Study of groundwater recharge in Rechna Doab using isotope techniques
International Nuclear Information System (INIS)
Sajjad, M.I.; Tasneem, M.A.; Ahmed, M.; Hussain, S.D.; Khan, I.H.; Akram, W.
1992-04-01
Isotopic studies were performed in the Rechna Doab area to understand the recharge mechanism, investigate the relative contributions from various sources such as rainfall, rivers and canal system and to estimate the turn over times and replenishment rate of groundwater. The isotopic data suggest that the groundwater in the project area can be divided into different zones each having its own characteristic isotopic composition. The enriched isotopic values show rain recharge and depleted isotopic values are associated with river/canal system while the intermediate isotopic values show a mixing of two or more sources of water. The major contribution, however, comes from canal system. The isotopic data suggest that there is no quick movement of groundwater in the area. 18 figs. (author)
Rechargeable radioactive isotope generator
International Nuclear Information System (INIS)
Thornton, A.K.; Cerone, F.E.
1978-01-01
The description is given of a rechargeable radioactive isotope generator having the following features: a box containing a transport shield, a shielded generator including elements for the absorption and holding of the parent isotope, an eluant tank, a first pipe causing this tank to communicate with the transport shield, a second pipe causing this transport shield to communicate with the shielded generator and a third pipe placing the shielded generator in communication with the outside of the unit. It also includes a shelf across the external front part of the unit a part of which is shielded by external components, a shielded elution flask in which the eluate is poured and a filter set at a point between the flask and the third pipe [fr
International Nuclear Information System (INIS)
A. Meijer; E. Kwicklis
2000-01-01
This analysis is governed by the Office of Civilian Radioactive Waste Management (OCRWM) Analysis and Modeling Report Development Plan entitled ''Geochemical and Isotopic Constraints on Groundwater Flow Directions, Mixing and Recharge at Yucca Mountain'' (CRWMS M and O 1999a). As stated in this Development Plan, the purpose of the work is to provide an analysis of groundwater recharge rates, flow directions and velocities, and mixing proportions of water from different source areas based on groundwater geochemical and isotopic data. The analysis of hydrochemical and isotopic data is intended to provide a basis for evaluating the hydrologic system at Yucca Mountain independently of analyses based purely on hydraulic arguments. Where more than one conceptual model for flow is possible, based on existing hydraulic data, hydrochemical and isotopic data may be useful in eliminating some of these conceptual models. This report documents the use of geochemical and isotopic data to constrain rates and directions of groundwater flow near Yucca Mountain and the timing and magnitude of recharge in the Yucca Mountain vicinity. The geochemical and isotopic data are also examined with regard to the possible dilution of groundwater recharge from Yucca Mountain by mixing with groundwater downgradient from the potential repository site. Specifically, the primary tasks of this report, as listed in the AMR Development Plan (CRWMS M and O 1999a), consist of the following: (1) Compare geochemical and isotopic data for perched and pore water in the unsaturated zone with similar data from the saturated zone to determine if local recharge is present in the regional groundwater system; (2) Determine the timing of the recharge from stable isotopes such as deuterium ( 2 H) and oxygen-18 ( 18 O), which are known to vary over time as a function of climate, and from radioisotopes such as carbon-14 ( 14 C) and chlorine-36 ( 36 Cl); (3) Determine the magnitude of recharge from relatively
Stable isotopic data for inferring source of groundwater recharge in the Anekal Taluk, Karnataka
International Nuclear Information System (INIS)
Ansari, Md. Arzoo; Deodhar, Archana; Jaryal, Ajay; Mendhekar, G.N.; Sinha, U.K.; Dash, Ashutosh; Davis, Deljo
2015-01-01
Occurrence of groundwater mainly depends on recharge area characteristics such as slope of the topography, surface cover characteristics, geology of the area and the permeability of top soil etc. Most of the tube wells located in the study area are in unconfined aquifer and the hydrology of them is mainly influenced by rainfall and surrounding catchments area characteristics. Isotope techniques provide a unique tool for establishing the recharge areas of groundwater. The stable Isotopes of O and H in water behave chemically conservative below 60 - 80°C and their concentrations are not affected by geochemical reactions in normal aquifers. Therefore, groundwater preserves its isotopic fingerprint, reflecting the history and origin before infiltration. This makes it an useful tool to interpret recharge mechanisms and the flow system. Therefore, an isotope hydrological technique has been applied in Anekal (12 deg 47 min 44 sec N; 77 deg 41 min 29 sec E) to identify the groundwater recharge area. Groundwater samples were collected from the study areas and analyzed for environmental Isotope (δ 2 H, δ 18 O) by a Isotope ratio mass spectrometer (IsoPrime-100) using gas equilibration method. Physico-chemical parameters (Temperature, EC, pH) were measured insitu. Electrical conductivity (EC) of the groundwater ranges from 668 to 2139 μS/cm, which is dependent on their travel path and the associated rock-water interaction (dissolution of rock minerals)
International Nuclear Information System (INIS)
Edmunds, W.
1988-07-01
Against the background of recent droughts in the Sahel and the overexploitation of scarce water resources, new and improved techniques for recharge estimation in arid lands are now needed. Results have been obtained from the Butana area of Sudan where rainfall is presently well below 200 mm a -1 . Profiles of the unsaturated zone moisture were analysed for solutes and oxygen (δ 18 O) and hydrogen (δD) isotope ratios to estimate the extent of current recharge. Chloride concentrations were compared with those from rainfall inputs and the ratio used to estimate long term recharge values. Direct recharge proved to be below 1 mm a -1 and the unsaturated zone (25 m approx) contained around 2000 years storage. Isotopic profiles indicated that in some areas discharge from the water table was occurring. Within the Butana region of Sudan, therefore, current recharge rates in interfluve areas are effectively zero. Lateral recharge is however occurring, based on the presence of tritium, from the wadi systems. This forms the only replenishable resource which has been successfully exploited by traditional means, although under stress in the present dry period. The River Nile can be shown from isotopic results to recharge laterally some 10 km; but the deeper resources elsewhere are palaeowaters replenished during Holocene wet periods (6000-8000 BP). 2 refs, 6 figs
Recharge Estimation Using Water, Chloride and Isotope Mass Balances
Dogramaci, S.; Firmani, G.; Hedley, P.; Skrzypek, G.; Grierson, P. F.
2014-12-01
Discharge of surplus mine water into ephemeral streams may elevate groundwater levels and alter the exchange rate between streams and underlying aquifers but it is unclear whether volumes and recharge processes are within the range of natural variability. Here, we present a case study of an ephemeral creek in the semi-arid subtropical Hamersley Basin that has received continuous mine discharge for more than five years. We used a numerical model coupled with repeated measurements of water levels, chloride concentrations and the hydrogen and oxygen stable isotope composition (δ2H and δ18O) to estimate longitudinal evapotranspiration and recharge rates along a 27 km length of Weeli Wolli Creek. We found that chloride increased from 74 to 120 mg/L across this length, while δ18O increased from -8.24‰ to -7.00‰. Groundwater is directly connected to the creek for the first 13 km and recharge rates are negligible. Below this point, the creek flows over a highly permeable aquifer and water loss by recharge increases to a maximum rate of 4.4 mm/d, which accounts for ~ 65% of the total water discharged to the creek. Evapotranspiration losses account for the remaining ~35%. The calculated recharge from continuous flow due to surplus water discharge is similar to that measured for rainfall-driven flood events along the creek. Groundwater under the disconnected section of the creek is characterised by a much lower Cl concentration and more depleted δ18O value than mining discharge water but is similar to flood water generated by large episodic rainfall events. Our results suggest that the impact of recharge from continuous flow on the creek has not extended beyond 27 km from the discharge point. Our approach using a combination of hydrochemical and isotope methods coupled with classical surface flow hydraulic modelling allowed evaluation of components of water budget otherwise not possible in a highly dynamic system that is mainly driven by infrequent but large episodic
A geochemical and isotopic approach to recharge evaluation in semi-arid zones. Past and present
International Nuclear Information System (INIS)
Edmunds, W.M.; Walton, N.R.G.
1980-01-01
The magnitude of any recharge to aquifers in semi-arid and arid zones is the principal uncertainty in estimating a water balance. Recent studies in Cyprus and Libyan Arab Jamahiriya are currently being used to demonstrate the application of geochemical and isotopic techniques, to the determination of both current and palaeo-recharge. In Cyprus, solute profiles of the unsaturated zone have been interpreted to provide estimates of the direct recharge component using a steady-state, mass-balance approach; results from the chloride profiles compare well with recharge estimates using tritium. In addition, it is found that some solute peaks, notably for specific electrical conductance, give a reasonably accurate record of the rainfall history during the period 1950-1975. The solute profile method is relatively unsophisticated and could be more widely applied to recharge estimation in other semi-arid areas of the world. In Libya, a clear distinction can be made using the combined isotopic, hydrological and geochemical results between regional groundwaters recharged to the upper, unconfined aquifer of the Sirte Basin before 13,000 years BP and younger waters recharged locally during the period 5000-7800 years BP. A well-defined fresh-water channel, superimposed upon the regional water quality pattern, can be traced within the aquifer for some 130 km and represents direct evidence of recharge during the Holocene. Some shallow groundwaters of similar composition to the fresh-water channel are also considered to represent recent, if intermittent, recharge which took place during historical times. It is concluded that geochemical and isotopic studies of both the unsaturated zone and of shallow groundwaters in semi-arid regions, can be used to determine not only the present-day direct recharge component, but also a recharge chronology of immediate historic times, which may be important in the estimation of long-term water resources. (author)
Use of environmental isotope tracer and GIS techniques to estimate basin recharge
Odunmbaku, Abdulganiu A. A.
The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin. Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably affects groundwater recharge. Depending on precipitation, soil chemistry, groundwater chemical composition, gradient and depth, the age and rate of recharge can be estimated. This present research proposes to estimate the recharge in Mimbres, Tularosa and Diablo Basin using the chloride environmental isotope; chloride mass-balance approach and GIS. It also proposes to determine the effect of elevation on recharge rate. Mimbres and Tularosa Basin are located in southern New Mexico State, and extend southward into Mexico. Diablo Basin is located in Texas in extends southward. This research utilizes the chloride mass balance approach to estimate the recharge rate through collection of groundwater data from wells, and precipitation. The data were analysed statistically to eliminate duplication, outliers, and incomplete data. Cluster analysis, piper diagram and statistical significance were performed on the parameters of the groundwater; the infiltration rate was determined using chloride mass balance technique. The data was then analysed spatially using ArcGIS10. Regions of active recharge were identified in Mimbres and Diablo Basin, but this could not be clearly identified in Tularosa Basin. CMB recharge for Tularosa Basin yields 0.04037mm/yr (0.0016in/yr), Diablo Basin was 0.047mm/yr (0.0016 in/yr), and 0.2153mm/yr (0.00848in
Prada, Susana; Cruz, J. Virgílio; Figueira, Celso
2016-05-01
The hydrogeology of volcanic islands remains poorly understood, despite the fact that populations that live on them rely on groundwater as a primary water source. This situation is exacerbated by their complex structure, geological heterogeneity, and sometimes active volcanic processes that hamper easy analysis of their hydrogeological dynamics. Stable isotope analysis is a powerful tool that has been used to assess groundwater dynamics in complex terrains. In this work, stable isotopes are used to better understand the hydrogeology of Madeira Island and provide a case-study that can serve as a basis for groundwater studies in other similar settings. The stable isotopic composition (δ18O and δ2H) of rain at the main recharge areas of the island is determined, as well as the sources and altitudes of recharge of several springs, groundwater in tunnels and wells. The water in tunnels was found to be recharged almost exclusively by rain in the deforested high plateaus, whilst several springs associated with shallow perched aquifers are recharged from rain and cloud water interception by the vegetated slopes. Nevertheless some springs thought to be sourced from deep perched aquifers, recharge in the central plateaus, and their isotopic composition is similar to the water in the tunnels. Recharge occurs primarily during autumn and winter, as evidenced by the springs and tunnels Water Lines (WL). The groundwater in wells appears to originate from runoff from rain that falls along the slopes that infiltrates near the streams' mouths, where the wells are located. This is evident by the evaporation line along which the wells plot. Irrigation water is also a possible source of recharge. The data is compatible with the hydrogeological conceptual model of Madeira. This work also shows the importance of cloud water interception as a net contributor to groundwater recharge, at least in the perched aquifers that feed numerous springs. As the amount of rainfall is expected to
Keesari, Tirumalesh; Sharma, Diana A; Rishi, Madhuri S; Pant, Diksha; Mohokar, Hemant V; Jaryal, Ajay Kumar; Sinha, U K
2017-11-01
Groundwater samples collected from the alluvial aquifers of southwest Punjab, both shallow and deep zones were measured for environmental tritium ( 3 H) and stable isotopes ( 2 H and 18 O) to evaluate the source of recharge and aquifer dynamics. The shallow groundwater shows wide variation in isotopic signature (δ 18 O: -11.3 to -5.0‰) reflecting multiple sources of recharge. The average isotopic signature of shallow groundwaters (δ 18 O: -6.73 ± 1.03‰) is similar to that of local precipitation (-6.98 ± 1.66‰) indicating local precipitation contributes to a large extent compared to other sources. Other sources have isotopically distinct signatures due to either high altitude recharge (canal sources) or evaporative enrichment (irrigation return flow). Deep groundwater shows relatively depleted isotopic signature (δ 18 O: -8.6‰) and doesn't show any evaporation effect as compared to shallow zone indicating recharge from precipitation occurring at relatively higher altitudes. Environmental tritium indicates that both shallow ( 3 H: 5 - 10 T.U.) and deeper zone ( 3 H: 1.5 - 2.5 T.U.) groundwaters are modern. In general the inter-aquifer connections seem to be unlikely except a few places. Environmental isotope data suggests that shallow groundwater is dynamic, local and prone to changes in land use patterns while deep zone water is derived from distant sources, less dynamic and not impacted by surface manifestations. A conceptual groundwater flow diagram is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Wan Zakaria Wan Muhamad Tahir; Nur Hayati Hussin; Ismail Yusof; Kamaruzaman Mamat; Johari Abdul Latif; Rohaimah Demanah
2014-01-01
Estimation and understanding of groundwater recharge mechanism and capacity of aquifer are essential issues in water resources investigation. An integrated study of environmental chloride content in the unsaturated zone using chloride mass balance method (CMB) and isotopic analyses of deuterium, oxygen-18, and tritium values range in the alluvial channel aquifer profiles (quaternary sediments) of the North Kelantan River basin has been carried out in order to estimate and understand groundwater recharge processes. However, the rate of aquifer recharge is one of the most difficult factors to measure in the evaluation of ground water resources. Estimation of recharge, by whatever method, is normally subject to large uncertainties and errors. In this paper, changes in stable isotopic signatures in different seasons and tritium analysis of the sampled groundwater observed at different depth in the aquifer system were evaluated. Stable isotope data are slightly below the local meteoric water line (LMWL) indicating that there is some isotopic enrichment due to direct evaporation through the soil surface which is exposed prior or during the recharging process. The overall data on water isotopic signatures from boreholes and production wells (shallow and relatively deep aquifer system) are spread over a fairly small range but somewhat distinct compared to river water isotopic compositions. Such a narrow variation in isotopic signatures of the sampled groundwaters may suggest that all groundwater samples originated from the same area of direct recharge predominantly from rainfall and nearby rivers. Environmental tritium data measured in groundwater at different depths and locations together with a medium-term of limited monthly rainfall collections were used to investigate the groundwater age distributions (residence times). The existence of groundwater in the aquifer system (sampled wells) is predominantly designated as modern (young) water that has undergone recharged
International Nuclear Information System (INIS)
Shivanna, K.; Tirumalesh, K.; Noble, J.; Joseph, T.B.; Singh, Gursharan; Joshi, A.P.; Khati, V.S.
2008-01-01
Environmental isotope techniques have been employed to identify the recharge areas of springs in India, in order to construct artificial recharge structures for rainwater harvesting and groundwater augmentation for their rejuvenation. A model project was taken up in the mountainous region of Gaucher area, Chamoli District, Uttarakhand for this purpose. The springs in this regions are seasonal and are derived from seepage waters flowing through the shallow weathered and fractured zone. The chemistry of high-altitude springs is similar to that of precipitation, whereas water-rock interactions contributes to increased mineralization in low-altitude springs. The stable isotopic variation in precipitation suggests that the altitude effect for Gaucher area is -0.55% for δ 18 O and -3.8% for δ 2 H per 100 m rise in altitude. Based on local geology, geomorphology, hydrochemistry and isotope information, the possible recharge areas inferred for valleys 1, 2 and 3 are located at altitudes of 1250, 1330 and 1020 m amsl respectively. Water conservation and recharge structures such as subsurface dykes, check bunds and contour trenches were constructed at the identified recharge areas in the respective valleys for controlling the subsurface flow, rainwater harvesting and groundwater augmentation respectively. As a result, during and after the following monsoon, the discharge rates of the springs not only increased significantly, but also did not dry up even during the dry period. The study shows that the isotope techniques can be effectively used in identifying recharge areas of springs in the Himalayan region. It also demonstrates the advantage of isotope techniques over conventional methods. (author)
International Nuclear Information System (INIS)
Trabelisi, R.; Zouari, K.
2012-12-01
Southern Tunisia is characterized by the presence of several hydrogeological basins, which extend over Tunisian borders. The Djeffara aquifer is one of the most important aquifer systems n this area and contains several interconnected aquifer levels. Stable (δ 2 H, δ 18 O and δ 13 C) and radioactive isotopes (1 4C , 3 H ) have been used to evaluate recharge mechanisms and groundwater residence time in the Djeffara multi-aquifer. Thesis aquifer presents two compartments, the first one ( west of the Medenine fault system) is unconfined with a well defined isotope fingerprint, the second compartment is deeper and confined multi- tracer results show groundwater of different origins, and ages , and that tectonic features control ground water flows. The unconfined part was mostly recharged during the Holocene. The recharge rates of this aquifer, inferred by 1 4C ages, are variable and could reach 3.5 mm/year. However, stable isotope composition and 1 4 'C content of the confined groundwater indicates carrier recharge during late pelistocene cold periods. (Author)
Energy Technology Data Exchange (ETDEWEB)
Zouari, K.; Trabelsi, R.; Kacem, A. [Laboratory of Radio-Analysis and Environment, ENIS, Sfax (Tunisia)
2013-07-15
Water resource issues constitute a major concern in arid and semiarid areas in Tunisia. To meet rising demand for different human activities considerable importance is being given to improving the natural groundwater recharge by the installation of hydraulic catchments. In central Tunisia, numerous retention sites and dams have been built since 1990, for example, the el Ogla dam in the Nadhour-Saouaf basin. In order to determine the implication of these hill reservoirs on the hydrodynamic functioning and water quality of the aquifer system, hydrochemical (major elements) and isotopic methods have been employed. The interpretation of these results showed that the shallow aquifer is recharged mainly by surface water and water dam infiltration from the el Ogla and Sahel catchments. A tentative isotopic mass balance based on stable isotope contents leads to the quantification of the artificial recharge rate, which ranges between 42% and 86% of precipitation in the humid period. (author)
Isotopic and hydrochemical evidence of groundwater recharge in the Hopq Desert, NW China
International Nuclear Information System (INIS)
Jian Ge; Tao Wang; Yafei Chen; Jiansheng Chen; Hohai University, Nanjing, Jiangsu Province; Lu Ge; Chao Wang
2016-01-01
Artesian wells and lakes are found in the hinterland of the Hopq Desert, China. Analysis of soil profiles has revealed that the local vadose zone is always in a state of water deficit because of strong evaporation, and precipitation cannot infiltrate into the groundwater. This research indicated that soil water and surface water are recharged by groundwater and that the groundwater is recharged via an external source. Analyses of the stable isotopes in precipitation and of the water budget suggested that surface water in the Qiangtang Basin on the Tibetan Plateau might correspond to the groundwater in the Hopq Desert. (author)
International Nuclear Information System (INIS)
Sajjad, M.I.; Tasneem, M.A.; Khan, I.H.; Ahmad, M.; Akram, W.
1992-01-01
Environmental isotopic investigation were carried out in Haripur plain to determine the recharge mechanism in the area. The Haripur plain is bounded by river Doar (that falls in Tarbela lake) in the north mountain ranges in the east and west, while the river Haro flows on the south eastern boundary upon which Khanpur dam has been built. Effort were made to identify the different sources which recharge the aquifer in the area. Isotopic data reveals that the major source of recharge is the rainfall on adjoining hills There is no contribution of Tarbela and Khanpur lakes. The residence time varies from a few years to more than fifty years depending upon the geology of the area. 14 figs. (author)
International Nuclear Information System (INIS)
Hassan, T.M.; Awad, M.A.; Hamza, M.S.
1994-01-01
The recharge rate is the most critical factor to groundwater resources management especially in semi-arid and arid areas. This paper presents a study on the feasibility of a groundwater development plan for south east egypt area. Environmental stable isotopes (oxygen-18 and deuterium), and hydro geochemistry techniques were used to investigate the recharge sources of groundwater. The examined groundwater wells tap the quaternary, basement and Nubian sandstone aquifers. The isotopic compositions of these groundwater samples indicate that there is a mixing among three different sources of recharge, local precipitation, palaeo water and sea water intrusion along the coastal plain, from the hydrochemical point of view, the predominant water types reflect meteoric, as well as marine waters genesis. The changes in salinity depend upon the dissolution of terrestrial salts, distance from the catchment area and seepage from deep aquifers. 7 figs., 2 tabs
Input of environmental isotopes in the study of the recharge and the flow dynamic of aquifers
International Nuclear Information System (INIS)
Aranyossy, J.F.; Njitchoua, R.; Zuppi, G.M.
1998-01-01
Several examples of hydrogeological studies have been selected in order to illustrate the input of environmental isotopic techniques in the general knowledge of aquifer systems: evaluation of the present aquifer recharge (Mali, Senegal, Italy, North-Cameroon, North-Sahara, Niger); evidence of the recharge variation with time (Niger, Italy, Vietnam); evaluation of the aquifer characteristics and hydraulic conditions (Chad, Niger). Most of these studies were carried out in collaboration with Professor Jean-Charles Fontes. (author)
International Nuclear Information System (INIS)
Mabiala, M.P.; Nlandu, W.J.; Ndembo, L.J.
2005-01-01
The stable isotopic content of daily precipitation sampled at Mount Amba (CGEA) shows large variations principally due to climatic conditions during rain events and to the type of air masses, which generaed the precipitation. The isotopic values of groundwater suggest, throughout the study zone, a rapid and easy recharge of the aquifers by direct infiltration precipitation. In some places, isotopic enrichment content could be attributed to evaporation processes during precipation. Groundwater is generally of chloride and sodium type. They are chemically good for drinking water, but localised high concentrations in nitrates indicate a risk of pollution of the aquifer.
Applying Environmental Isotope Theory to Groundwater Recharge in the Jiaozuo Mining Area, China
Directory of Open Access Journals (Sweden)
Pinghua Huang
2017-01-01
Full Text Available This study establishes the surface water evaporation line in theory and numerically simulates the δD and δ18O value distribution interval of the recharge source of deep groundwater in the Jiaozuo mining area. The recharge elevation is calculated based on hydrogen and oxygen isotope tracer theory. Theoretical calculation and experimental data indicate that the surface water evaporation line in the study area in theory is almost the same as the measured surface data-fitting line. A significant linear relationship is identified between δ18O and the elevation of spring outcrop. The topography increases per 100 m, and the δ18O value reduces by 0.23‰ on average. The δ18O value is converted into formula to calculate the groundwater recharge elevation, which is approximately from 400 to 800 m. The measured tritium values of karst groundwater are greater than 3 TU. The second factor score is a fraction distribution in shallow groundwater and negative fraction distribution in spring and deep groundwater, which indicates that the Northern Taihang Mountain is the main recharge area, where carbonate-exposed areas exist. The research conclusion holds a certain value for the flood evaluation of local coal mines.
International Nuclear Information System (INIS)
Mizutani, Yoshihiko; Sakurai, Kazuhiro
1988-01-01
The Joganjigawa Fan, an area of rice farming of 50 km 2 lies to the southeast of Toyama city and was formed in the Late Quarternary by terrestrial gravel deposition by the Joganji River. To identify sources of water in shallow aquifers (maximum depth 100 m) beneath the fan, studies of hydrogen and oxygen isotopes in the ground and surface waters of the fan have been made. Major rivers flowing onto the fan are from higher-altitude catchments (maximum altitude 3000 m) and have lower δ 18 D and δO values than rainfall on the fan. The isotopic measurements indicate that the aquifers are mainly recharged by infiltration of the irrigation water, which is derived from the Joganji River, and local precipitations from the surface. In narrow areas along the Jinzu and its tributary the Kumano Rivers, the aquifers are locally recharged from the Jinzu and Kumano Rivers, respectively. Chemical data support this identification of sources of water in the aquifers. (author)
Joshi, Suneel Kumar; Rai, Shive Prakash; Sinha, Rajiv; Gupta, Sanjeev; Densmore, Alexander Logan; Rawat, Yadhvir Singh; Shekhar, Shashank
2018-04-01
Rapid groundwater depletion from the northwestern Indian aquifer system in the western Indo-Gangetic basin has raised serious concerns over the sustainability of groundwater and the livelihoods that depend on it. Sustainable management of this aquifer system requires that we understand the sources and rates of groundwater recharge, however, both these parameters are poorly constrained in this region. Here we analyse the isotopic (δ18O, δ2H and tritium) compositions of groundwater, precipitation, river and canal water to identify the recharge sources, zones of recharge, and groundwater flow in the Ghaggar River basin, which lies between the Himalayan-fed Yamuna and Sutlej River systems in northwestern India. Our results reveal that local precipitation is the main source of groundwater recharge. However, depleted δ18O and δ2H signatures at some sites indicate recharge from canal seepage and irrigation return flow. The spatial variability of δ18O, δ2H, d-excess, and tritium reflects limited lateral connectivity due to the heterogeneous and anisotropic nature of the aquifer system in the study area. The variation of tritium concentration with depth suggests that groundwater above c. 80 mbgl is generally modern water. In contrast, water from below c. 80 mbgl is a mixture of modern and old waters, and indicates longer residence time in comparison to groundwater above c. 80 mbgl. Isotopic signatures of δ18O, δ2H and tritium suggest significant vertical recharge down to a depth of 320 mbgl. The spatial and vertical variations of isotopic signature of groundwater reveal two distinct flow patterns in the aquifer system: (i) local flow (above c. 80 mbgl) throughout the study area, and (ii) intermediate and regional flow (below c. 80 mbgl), where water recharges aquifers through large-scale lateral flow as well as vertical infiltration. The understanding of spatial and vertical recharge processes of groundwater in the study area provides important base-line knowledge
Recharge Area of Groundwater of Jakarta Basin
International Nuclear Information System (INIS)
Wandowo; Abidin, Zainal; Alip; Djiono
2002-01-01
Groundwater inside the earth contained in a porous and permeable layers called aquifers. Depend on the hydrogeological structure, the aquifers may be composed of independent layers separated each other by impermeable boundaries. Such a condition may effect the location of recharge where water is able to infiltrate and goes to the aquifers. The objective of this research is to find out and to locate the recharge area of Jakarta basin by utilizing stable isotopes 2H and 18O . The work was done by collecting shallow and deep groundwater samples throughout Jabotabek area and precipitations from different altitudes. Since the stable isotopes composition of precipitation is subject to the altitude, the recharge area would be able to be identified by assessing the correlation of stable isotopes composition of precipitation and corresponding groundwater population. The data obtained from this study suggested that shallow groundwater is originated from local recharge while deep groundwater is recharged from the area having altitude of 125 -230 meters, it correspond to the area between Depok and Bogor
International Nuclear Information System (INIS)
Davisson, M.L.; Criss, R.E.
1995-01-01
Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the δ 18 O values of groundwater were relatively homogeneous (mostly -7.0 ± 0.5 per-thousand), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high 18 O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low 18 O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in δ 18 O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are ∼10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for ∼40 years, creating cones of depression ∼25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low 18 O water (-11.0 per-thousand) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp 18 O gradients in our groundwater isotope map
Directory of Open Access Journals (Sweden)
M. Arnoux
2017-11-01
Full Text Available Lakes are under increasing pressure due to widespread anthropogenic impacts related to rapid development and population growth. Accordingly, many lakes are currently undergoing a systematic decline in water quality. Recent studies have highlighted that global warming and the subsequent changes in water use may further exacerbate eutrophication in lakes. Lake evolution depends strongly on hydrologic balance, and therefore on groundwater connectivity. Groundwater also influences the sensitivity of lacustrine ecosystems to climate and environmental changes, and governs their resilience. Improved characterization of groundwater exchange with lakes is needed today for lake preservation, lake restoration, and sustainable management of lake water quality into the future. In this context, the aim of the present paper is to determine if the future evolution of the climate, the population, and the recharge could modify the geochemistry of lakes (mainly isotopic signature and quality via phosphorous load and if the isotopic monitoring of lakes could be an efficient tool to highlight the variability of the water budget and quality. Small groundwater-connected lakes were chosen to simulate changes in water balance and water quality expected under future climate change scenarios, namely representative concentration pathways (RCPs 4.5 and 8.5. Contemporary baseline conditions, including isotope mass balance and geochemical characteristics, were determined through an intensive field-based research program prior to the simulations. Results highlight that future lake geochemistry and isotopic composition trends will depend on four main parameters: location (and therefore climate conditions, lake catchment size (which impacts the intensity of the flux change, lake volume (which impacts the range of variation, and lake G index (i.e., the percentage of groundwater that makes up total lake inflows, the latter being the dominant control on water balance conditions, as
Arnoux, Marie; Barbecot, Florent; Gibert-Brunet, Elisabeth; Gibson, John; Noret, Aurélie
2017-11-01
Lakes are under increasing pressure due to widespread anthropogenic impacts related to rapid development and population growth. Accordingly, many lakes are currently undergoing a systematic decline in water quality. Recent studies have highlighted that global warming and the subsequent changes in water use may further exacerbate eutrophication in lakes. Lake evolution depends strongly on hydrologic balance, and therefore on groundwater connectivity. Groundwater also influences the sensitivity of lacustrine ecosystems to climate and environmental changes, and governs their resilience. Improved characterization of groundwater exchange with lakes is needed today for lake preservation, lake restoration, and sustainable management of lake water quality into the future. In this context, the aim of the present paper is to determine if the future evolution of the climate, the population, and the recharge could modify the geochemistry of lakes (mainly isotopic signature and quality via phosphorous load) and if the isotopic monitoring of lakes could be an efficient tool to highlight the variability of the water budget and quality. Small groundwater-connected lakes were chosen to simulate changes in water balance and water quality expected under future climate change scenarios, namely representative concentration pathways (RCPs) 4.5 and 8.5. Contemporary baseline conditions, including isotope mass balance and geochemical characteristics, were determined through an intensive field-based research program prior to the simulations. Results highlight that future lake geochemistry and isotopic composition trends will depend on four main parameters: location (and therefore climate conditions), lake catchment size (which impacts the intensity of the flux change), lake volume (which impacts the range of variation), and lake G index (i.e., the percentage of groundwater that makes up total lake inflows), the latter being the dominant control on water balance conditions, as revealed by
Santoni, S.; Huneau, F.; Garel, E.; Celle-Jeanton, H.
2018-04-01
Climate change is nowadays widely considered to have major effects on groundwater resources. Climatic projections suggest a global increase in evaporation and higher frequency of strong rainfall events especially in Mediterranean context. Since evaporation is synonym of low recharge conditions whereas strong rainfall events are more favourable to recharge in heterogeneous subsurface contexts, a lack of knowledge remains then on the real ongoing and future drinking groundwater supply availability at aquifers scale. Due to low recharge potential and high inter-annual climate variability, this issue is strategic for the Mediterranean hydrosystems. This is especially the case for coastal aquifers because they are exposed to seawater intrusion, sea-level rise and overpumping risks. In this context, recharge processes and rates were investigated in a Mediterranean coastal aquifer with subsurface heterogeneity located in Southern Corsica (France). Aquifer recharge rates from combining ten physical and chemical methods were computed. In addition, hydrochemical and isotopic investigations were carried out through a monthly two years monitoring combining major ions and stable isotopes of water in rain, runoff and groundwater. Diffuse, focused, lateral mountain system and irrigation recharge processes were identified and characterized. A predominant focused recharge conditioned by subsurface heterogeneity is evidenced in agreement with variable but highly favourable recharge rates. The fast water transfer from the surface to the aquifer implied by this recharge process suggests less evaporation, which means higher groundwater renewal and availability in such Mediterranean coastal aquifers.
International Nuclear Information System (INIS)
Dharmasiri, J.K.; Morawska, L.
1997-01-01
Gatton is an important agricultural area for Queensland where about 40% of its vegetables needs are produced using groundwater as the main source. An alluvial Aquifer is located about 30m beneath the layers of alluvial sediments ranging from black soils of volcanic origin on top, layers of alluvial sands, clays and beds of sand and gravel. The leakage of creek flows has been considered to be the main source of recharge to this aquifer. A number of weirs have been built across the Lockyer and Laidley creeks to allow surface water to infiltrate through the beds when the creeks flow. Water levels in bores in a section located in the middle of the alluvial plain (Crowley Vale) have been declining for the last 20 years with little or no success in recharging from the creeks. Acute water shortages have been experienced in the Gatton area during the droughts of 1980-81, 1986-87 and 1994-97. Naturally occurring stable isotopes, 2 H, 18 0 and 13 C as well as radioisotopes 3 H and 14 C have been used to delineate sources of recharge and active recharge areas. Tritium tracing of soil moisture in the unsaturated soil was also used to determine direct infiltration rates
International Nuclear Information System (INIS)
AlKatheeri, E. S.; Murad, A. A.; Howari, F. M.
2007-01-01
Liwa area is located in the Western Region of the Abu Dhabi Emirate in UAE. Environmental isotopes namely 2 H , 1 8O and 3 H were used to study the Quaternary aquifer in the aforementioned area. The analyses indicate that groundwater samples obtained from the study area have significant variation of isotopic content. The range of δ2 H is from -17 to 16.5, while the δ1 8O is ranging from +1.07 to +6.05. This large variation in both oxygen and hydrogen contents may be related to different origin of groundwater. δ2 H - δ1 8O relationship points to potential evaporation of recharged water prior to infiltration as observed from the slope of 4 and y-intercept of about 9. The reported results demonstrate that investigated aquifer is recharged from high elevation source which is Northern Oman Mountains, as seen from the distribution of the samples relative to the LMWL. Groundwater samples have been classified based on their depth to shallow-medium aquifer and deep aquifer. Samples from deeper aquifer have depleted values of isotopes and this indicates that deep groundwater is ancient and originated from rains of different climatic regime.
Salameh, Elias
The recharge sources, the flow mechanisms and discharge areas of the different groundwater bodies underlying the Yarmouk River catchment area in Jordan, have, until now, not been adequately explained, although a wide range of hydrological, hydrogeological, and hydrochemical studies have been done. Along the Jordanian part of the catchment area of the Yarmouk River, groundwater issues from different aquifers with a variety of chemistries and types within the same aquifer and in between the different aquifers. Conventional recharge/discharge mechanisms, water balances and chemical analyses did not adequately explain the chemical variations and the different water types found in the area. Applying environmental isotopic tools combined with their altitude effects due to topographic variations (250-1,300 m a.s.l. within a distance of 20 km), and taking into consideration re-evaporation effects on the isotopic depletion and enrichment of rainwater, has greatly helped in understanding the recharge discharge mechanisms of the different aquifers. Precipitation along the highlands of an average of 600 mm/year is found to be depleted in its isotopic content of δO18 = -7.0 to -7.26 and δD = -32.2 to -33.28, whereas that of the Jordan Valley of 350 mm/year is highly enriched in isotopes with δO18 = -4.06 and δD = -14.5. The groundwater recharged along the highlands is depleted in isotopes (δO18 = -6, δD = -30), groundwater at the intermediate elevations is enriched (δO18 = -5, δD = -23) and that of the Jordan Valley aquifers containing meteoric water is highly enriched (δO18 -3.8, δD = -18). The deep aquifers in the Jordan Valley foothills are depleted in isotopes (δO18 -18 = -6, δD = -30) and resemble those of the highland aquifers. Only through using isotopes as a tool, were the sources of the different groundwater bodies and recharge and discharge mechanisms unambiguously explained. It was found that recharge takes place all over the study area and produces
International Nuclear Information System (INIS)
Palacio B, Paola Andrea; Betancur V, Teresita
2008-01-01
Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D 2H y 3H to study the aquifer system on Bajo Cauca antioqueno
International Nuclear Information System (INIS)
Shohaib, R.EL-SH.; Nada, A.; Safie El-Din, A.
1991-01-01
Groundwater samples collected from a number of localities in ataqa-north galala region were subjected to various chemical and isotopic analyses. The seasonal fluctuations in hydrochemical composition reveal that the marin Mg Cl 2 type is dominant in the aquifer through-out the year. The Ca Cl 2 water type of marine origin appears in January in wells W 3 and W 7 which lie close to sukhna fault. Recharge to the aquifer is reflected by fluctuation in the water level and fluctuations of the hydrochemical composition of the water. The results of the isotopic content of the water samples indicate that the connate marine water has been subjected to dilution and mixing by the meteoric water invasion since the pliestocene pluvial period (paleowater) and recent meteoric water precipitation. The bulk of the stored water ( about 80%) is paleowater and the recent water (20%) are percolate ones derived from the rain-fall at high latitudes.4 fig. 1 tab
International Nuclear Information System (INIS)
Saighi, O.
1999-01-01
In the crystalline and igneous Ahaggar massif, the water resources are found in some small-scale phreatic aquifers which are recharged by sporadic wadi floods. The most favourable aquifer zones are localized in the valleys, consisting of three overlying levels of varying importance: the alluvial aquifer, the weathered zone of the underlying substratum, and the deep aquifer of fissured basement, the extent of which is not limited only to wadis. In order to evaluate the recharge to the different aquifers, chemical and isotopic analyses have been carried out on a hundred samples taken at different depths. Measurements of oxygen-18, deuterium, carbon-13, carbon-14 and tritium have been carried out on these samples
Uribe, Javier; Muñoz, José F.; Gironás, Jorge; Oyarzún, Ricardo; Aguirre, Evelyn; Aravena, Ramón
2015-11-01
Closed basins are catchments whose drainage networks converge to lakes, salt flats or alluvial plains. Salt flats in the closed basins in arid northern Chile are extremely important ecological niches. The Salar del Huasco, one of these salt flats located in the high plateau (Altiplano), is a Ramsar site located in a national park and is composed of a wetland ecosystem rich in biodiversity. The proper management of the groundwater, which is essential for the wetland function, requires accurate estimates of recharge in the Salar del Huasco basin. This study quantifies the spatio-temporal distribution of the recharge, through combined use of isotopic characterization of the different components of the water cycle and a rainfall-runoff model. The use of both methodologies aids the understanding of hydrological behavior of the basin and enabled estimation of a long-term average recharge of 22 mm/yr (i.e., 15 % of the annual rainfall). Recharge has a high spatial variability, controlled by the geological and hydrometeorological characteristics of the basin, and a high interannual variability, with values ranging from 18 to 26 mm/yr. The isotopic approach allowed not only the definition of the conceptual model used in the hydrological model, but also eliminated the possibility of a hydrogeological connection between the aquifer of the Salar del Huasco basin and the aquifer that feeds the springs of the nearby town of Pica. This potential connection has been an issue of great interest to agriculture and tourism activities in the region.
Dogramaci, Shawan; Firmani, Giovanni; Hedley, Paul; Skrzypek, Grzegorz; Grierson, Pauline F.
2015-02-01
Dewatering associated with mining below water table to achieve dry mining conditions may exert significant pressure on water balance in terms of lowering the water table and change in the dynamics of interactions between surface water and groundwater. The discharge of surplus mine water into ephemeral streams may also affect the water balance, by elevating groundwater levels and altering the exchange rate between streams and underlying aquifers. However, it is unclear whether volumes and recharge processes are within the range of natural variability. Here, we present a case study of an ephemeral creek in the semi-arid Hamersley Basin of northwest Australia that has received continuous mine discharge for more than six years. We used a numerical model coupled with repeated measurements of water levels, chloride concentrations and the hydrogen and oxygen stable isotope composition (δ2H and δ18O) to estimate longitudinal evapotranspiration and recharge rates along a 27 km length of Weeli Wolli Creek. We found that chloride increased from 73 to 120 mg/L across this length, while δ18O increased from -8.2‰ to -7.00‰. Groundwater is directly connected to the creek for the first 13 km and recharge rates are negligible. Below this point, the creek flows over a highly permeable aquifer and water loss by recharge increases to a maximum rate of 4.4 mm/d, which accounts for ∼65% of the total water discharged to the creek. Evapotranspiration losses account for the remaining ∼35%. The calculated recharge from continuous flow due to surplus water discharge is similar to that measured for rainfall-driven flood events along the creek. Groundwater under the disconnected section of the creek is characterised by a much lower Cl concentration and more depleted δ18O value than mining discharge water but is similar to flood water generated by large episodic rainfall events. Our results suggest that the impact of recharge from continuous flow on the water balance of the creek
Ginn, T.R.; Woolfenden, L.
2002-01-01
A project for modeling and isotopic analysis of artificial recharge in the Rialto-Colton basin aquifer in California, is discussed. The Rialto-Colton aquifer has been divided into four primary and significant flowpaths following the general direction of groundwater flow from NW to SE. The introductory investigation include sophisticated chemical reaction modeling, with highly simplified flow path simulation. A comprehensive reactive transport model with the established set of geochemical reactions over the whole aquifer will also be developed for treating both reactions and transport realistically. This will be completed by making use of HBGC123D implemented with isotopic calculation step to compute Carbon-14 (C14) and stable Carbon-13 (C13) contents of the water. Computed carbon contents will also be calibrated with the measured carbon contents for assessment of the amount of imported recharge into the Linden pond.
International Nuclear Information System (INIS)
Verhagen, B.Th.; Bredenkamp, D.B.; Janse van Rensburg, H.; Farr, J.L.
1999-01-01
Environmental isotope data from a 'snapshot' sampling hold out the promise of producing acceptable estimates of ground water recharge for resource management purposes. In three major ground water developments in Botswana, estimates of recharge to the Karoo aquifers in the Kalahari, were based on residence times derived from radiocarbon data. In the assessment, three factors needed to be considered: 1) the model leading to acceptable values of residence times 2) the initial, or recharge, radiocarbon value and 3) appropriate values of aquifer porosity. In the three studies, porosity had been measured on numerous drill cores obtained from the principal fractured sandstone aquifers. The resulting isotope-based recharge values correspond reasonably with independent recharge assessments using the equal volume method to analyse long-term rest level observations in two cases; in the third, recharge was independently assessed on the basis of chloride balance in both unsaturated and saturated zones. It is concluded that a) the isotope snapshot approach can give acceptable values for recharge in the development of ground water resources, providing rational management information early in the life of a ground water supply scheme; b) the exponential model and an initial radiocarbon values of 85% atmospheric are realistic in this environment and c) the total porosity appears to be the appropriate parameter in the calculation of recharge. This also provides an insight into the behaviour of the aquifers. (author)
Aquifer recharging in South Carolina: radiocarbon in environmental hydrogeology
International Nuclear Information System (INIS)
Stone, P.A.; Knox, R.L.; Mathews, T.D.
1985-01-01
Radiocarbon activities of dissolved inorganic carbon (and tritium activities where infiltration rates are rapid and aquifers shallow) provide relatively unambiguous and inexpensive evidence for identification of significant recharge areas. Such evidence is for the actual occurrence of modern recharge in the aquifer and thus is less inferential than stratigraphic or potentiometric evidence. These underutilized isotopic techniques are neither arcane nor complex and have been more-or-less standardized by earlier researchers. In South Carolina, isotopic evidence has been used from both calcareous and siliceous sedimentary aquifers and fractured crystalline rock aquifers. The Tertiary limestone aquifer is shown not to be principally recharged in its subcrop area, unlike conditions assumed for many other sedimentary aquifers in southeastern United States, and instead receives considerable lateral recharge from interfingering updip Tertiary sand aquifers in the middle coastal plain. Induced recharging at Hilton Head Island is mixing ancient relict water and modern recharge water. Recharging to deeper portions of the Cretaceous Middendorf basal sand aquifer occurs at least as far coastward as the middle coastal plain, near sampling sites that stratigraphically appear to be confined. Pronounced mineralization of water in fractured rocks cannot be considered as evidence of ancient or relict ground water that is isolated from modern contaminants, some of these waters contain considerable radiocarbon and hydrogen-bomb tritium
International Nuclear Information System (INIS)
Mokrik, R.; Mazeika, J.
2002-01-01
Several hypotheses were established to explain low δ 18 O values of groundwater which have been found in the Estonian Homocline. Traces of depleted groundwater were found also in other parts of the Baltic Basin near the shoreline. From data collected in this and previous studies, the δ 18 O values of groundwater in most aquifers are known to range from -7.7 to -13.9 per mille. However, the groundwater in Estonia in the Cambrian-Vendian aquifer system has significantly lower δ 18 O values, which vary mainly from -18 to -22.5 per mille. The overlying Ordovician-Cambrian aquifer is also depleted in 18 O, but, as a rule, the degree of depletion is several per mille less than in case of the Cambrian- Vendian aquifer. The thickness of the depleted water in Estonia reaches 450 m. At similar depths beneath Gotland Island (Sweden Homocline), groundwater has significantly higher δ 18 O values (from -5.7 to -6.1 per mille). A hydrogeologic model, depicting conditions during the pre Late Glacial, and accounting for hydraulic connections between the lake and river systems through taliks in permafrost, was developed to explain the observed groundwater isotope data. According to the adopted model, penetration of isotopically depleted surface waters could have reached depths of up to 500 m, with subsequent mixing between subglacial meltwater and old groundwater of Huneborg-Denekamp time. Traces of this penetration were discovered only near the shoreline, where δ 18 O values vary from -12 to -13.9 per mille and 14 C is below 4%. In the territory of the Estonian Homocline, the hydraulically close connection via the Cambrian-Vendian aquifer between talik systems of the Gulf of Riga and the Gulf of Finland existed through permafrost before the Late Glacial. This was due to subglacial recharge during the recessional Pandivere (12 ka BP) and Palivere (11.2 ka BP) phases, which is also associated with recharge of isotopically depleted groundwater. (author)
Contribution to the study of the recharge of Morondava hydrogeological basin
International Nuclear Information System (INIS)
RAHOBISOA, J.J.
2006-01-01
Stables isotopes and radioisotopes, combinated with hydrogeological data and hydrochemical data have been applied in the investigation of the groundwater recharge of the Morondava plain. This area is located in the south western of Madagascar, in the catchment of Morondava river. The dominant hydrochemical type of the groundwaters in the study area is of calcium-bicarbonate, with sodium chloride type in the coastal and central areas. They may originate from dissolution of limestone; or from hydrolysis of Anorthite; or from sea sprays. The phreatic aquifer receives both direct and lateral recharge by rainfall. The average recharge rate is estimated to 165,7 to 182,7 mm/a corresponding to a recharge of 250 614.10 3 to 276 318.10 3 m 3 /a. As for the deeper aquifer, the groundwater recharge area is mainly located in Tsiandava plateau according to the isotopic recharge altitude calculations. As for the phreatic aquifer, tritium values have provided a mean residence time of 56 years. As for the deeper aquifers, the 14 C groundwater age ranges between 1400 and 1985 years [fr
Groundwater Recharge Process in the Morondava Sedimentary Basin, Southwestern Madagascar
International Nuclear Information System (INIS)
Mamifarananahary, E.; Rajaobelison, J.; Ramaroson, V.; Rahobisoa, J.J.
2007-01-01
The groundwater recharge process in the Morondava Sedimentary basin was determined using chemical and isotopic tools. The results showed that the main recharge into shallow aquifer is from infiltration of evaporated water. Into deeper aquifer, it is done either from direct infiltration of rainfall from recharge areas on the top of the hill in the East towards the low-lying discharge areas in the West, or from vertical infiltration of evaporated shallow groundwater. The tritium contents suggest that recharge from shallow aquifers is from recent rainfall with short residence time while recharge into deeper aquifers is from older rainfall with longer residence time.
Groundwater Recharge Processes Revealed By Multi-Tracers Approach in a Headwater, North China Plain
Sakakibara, K.; Tsujimura, M.; Song, X.; Zhang, J.
2014-12-01
Groundwater recharge variation in space and time is crucial for effective water management especially in arid/ semi-arid regions. In order to reveal comprehensive groundwater recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were conducted at 4 times in different seasons in Wangkuai watershed, Taihang Mountains, which is a main groundwater recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate was observed in stable state condition. The stable isotopic compositions, silica and bicarbonate concentrations in the groundwater show close values as those in the surface water, suggesting main groundwater recharge occurs from surface water at mountain-plain transitional zone throughout a year. Also, the deuterium and oxgen-18 in the Wangkuai reservoir and the groundwater in the vicinity of the reservoir show higher values, suggesting the reservoir water, affected by evaporation effect, seems to have an important role for the groundwater recharge in alluvial plain. For specifying the groundwater recharge area and quantifying groundwater recharge rate from the reservoir, an inversion analysis and a simple mixing model were applied in Wangkuai watershed using stable isotopes of oxygen-18 and deuterium. The model results show that groundwater recharge occurs dominantly at the altitude from 357 m to 738 m corresponding to mountain-plain transitional zone, and groundwater recharge rate by Wangkuai reservoir is estimated to be 2.4 % of total groundwater recharge in Wangkuai watershed.
Using Isotopes for Design and Monitoring of Artificial Recharge Systems
International Nuclear Information System (INIS)
2013-11-01
Over the past years, the IAEA has provided support to a number of Member States engaged in the implementation of hydrological projects dealing with the design and monitoring of artificial recharge (AR) systems, primarily situated in arid and semiarid regions. AR is defined as any engineered system designed to introduce water to, and store water in, underlying aquifers. Aquifer storage and recovery (ASR) is a specific type of AR used with the purpose of increasing groundwater resources. Different water management strategies have been tested under various geographical, hydrological and climatic regimes. However, the success of such schemes cannot easily be predicted, since many variables need to be taken into account in the early stages of every AR project. As often occurs in the case of the assessment and management of groundwater and aquifers, information on hydrological behaviour and response to human-made actions is difficult to obtain and often very costly, especially if only conventional hydrological methods are used. Classical methods in AR and ASR are meant to provide information on changes in the volume and quality of the artificially introduced water to ensure its sustainability. Although the use of isotopes and geochemical tracers to plan and monitor AR and ASR has been limited, there is a growing number of publications reporting the successful application of tracers in the different phases of AR and ASR schemes. This publication discusses several theoretical aspects important to the understanding, planning and monitoring of AR and ASR schemes and presents a selected number of examples illustrating the usefulness of isotopes and other tracers. One section presents the list of available isotope tracers, indicating the type of information that can be obtained from each. The case studies presented in this publication illustrate the use of these tools in the different stages of AR and ASR schemes. The publication is expected to be of interest to hydrologists
Geochemical and isotopic methods for management of artificial recharge in mazraha station (Damascus)
International Nuclear Information System (INIS)
Abou Zakhem, B.; Hafez, R.; Kadkoy, N.
2009-11-01
Artificial recharge of shallow groundwater at specially designed facilities is an attractive option increasing the storage capacity of potable water in arid and semi arid region such as Syria, Damascus Oasis. This operation needs integral management and detailed knowledge of groundwater dynamics and quantity and quality development of water. The objective of this study is to determine the temporal and spatial variations of chemical and environmental isotopic characteristics of groundwater during injection and recovery process. The geochemical and environmental isotope techniques are ideally suited for these investigations. 400 to 500 x10 3 m 3 of spring water were injected annually into the ambient groundwater in Mazraha station, Damascus Oasis, which is used later for drinking purpose. Native groundwater and injected water are calcium bicarbonate type with EC of about 850±100 μS/cm and 300±50 μS/cm respectively. The injected water is under saturated with respect to calcite, while ambient groundwater is over saturated and the mixed water is in equilibrium after injection. It was observed that The injection process created a dilution cloud decreasing chemical concentrations progressively that improve the groundwater quality. After completed injection, the dilution center moved about 200 m during 85 days to the south southeast according to the ambient groundwater flow path. Based on this observation, the hydraulic conductivity of the aquifer is estimated about 7.5±1.3x10 -4 m/s. The spatial distribution maps of CFC-11 and CFC-12, after injection, showed the same shape and flow direction of the spatial distribution of chemical elements. The effective diameter of artificial recharge is limited to about 250 m from the injection wells, as EC, Cl- and NO 3 - concentrations are effected significantly. Mixing ratio of 30% is required in order to lower nitrate concentration to less than 50 mg/l in native groundwater for potable water. Depending on pumping rate, the
International Nuclear Information System (INIS)
Vachier, P.; Dever, L.; Fontes, J.C.
1987-01-01
Water from the unsaturated zone in the chalk, obtained from porous plugs, was subjected to chemical and isotope analyses over a three-year period. Tensiometric and volumetric water content measurements were carried out at the same time. The results obtained make it possible to establish an outline of the hydrodynamics of this porous, fissured chalk medium. Matrix porosity was 0.42 while fissure porosity was in the region of 0.01. The tritium and nitrate concentrations in the water fix the mean residence time in the 20-metre unsaturated zone at about 30 years. The isotope profiles ( 18 O and 3 H) and their downward displacements make it possible to estimate the mean annual recharge into the unconfined groundwater in the chalk (200 to 300 mm, depending on plant cover). The vertical movement of the solution in the porous matrix is dominated by the piston effect. Variations in 18 O concentration can be correlated with local climatic fluctuations. The recharge period runs from November to March, with summer rainfall playing no part. A comparison of 2 H and 18 O concentrations shows that even winter rainfall is partially removed by evaporation. (author). 17 refs, 11 figs, 1 tab
International Nuclear Information System (INIS)
Al-Charideh, A.
2012-03-01
Karst aquifers represents an important groundwater resources not only in Syria, but in the world-wide. The hydrological approaches for studying the karst system were developed in the last tow decade. One of the main approaches is the use of natural isotopes and hydrochemical traces for description the recharge and discharge and estimate the recharge rate of karst aquifer system. The main filed site tests are the Figeh and Barada karst aquifer, located in the carbonate rocks of the Anti-Lebanon Mountains. Environmental isotopes and chemical major ions (δ 18 Ο, δ 2 H and 3 H), in precipitation and groundwater were integrated for studying the isotope and hydrochemical characterization and the description of temporal variations of groundwater discharge from the karst springs of Figeh and Barada which are considered as the main large springs due to there huge discharge in the Anti-Lebanon Mountains. The δ 18 O values are -8.9 and -7.7. for Figeh and Barada respectively. The regression line for both precipitation and groundwater discharge from Figeh and Barada is described by the equation: δD = 7.9δ 18 O + 19.7 wish shows no evaporation during precipitation and suggest that the groundwater are mainly from direct infiltration of precipitation. The altitude gradients in the precipitation were estimated to be -0.23./100 m for δ 18 O. The main recharge areas were estimated to be 2000±50 and 1350±50 m.a.s.l for Figeh and Barada springs.The chloride mass balance (CMB) method was used to quantify recharge rates of groundwater in the Mountain karst aquifer of Figeh spring. The recharge rate varies from 192 to 825 mm year-1, which corresponds to 43 and 67% of the total annual rainfall. Recharge rates estimated by CMB were compared with values obtained from other methods and were found to be in good agreement. The tritium concentrations in groundwater are low and very close to the rainfall value 4.5 Tu for meteoric stations. Adopting a model with exponential time
Groundwater problems studies in the Thar desert, India, using isotope techniques
International Nuclear Information System (INIS)
Navada, S.V.
1999-01-01
In groundwater management, particularly in arid regions like western Rajasthan, it is important to know the presence of modern recharge and to estimate the recharge rate to avoid over-exploitation of the groundwater resource. Isotopes can help to identify modern recharge and to estimate recharge rate to the aquifer. If modern recharge is absent, groundwater dating using radiocarbon could help to identify old groundwater or paleowaters. A number of isotope studies carried out in arid zones (particularly in the Sahara) have shown that the deep groundwater is generally very old. From these studies it was concluded that episodic large scale recharge corresponding to humid phases or pluvials occurred in these arid areas. The paper reviews our experiences on the application of isotope techniques in understanding groundwater recharge process in and western Rajasthan
Fractionation of boron isotopes in Icelandic hydrothermal systems
International Nuclear Information System (INIS)
Aggarwal, J.K.
1995-01-01
Boron isotope ratios have been determined in a variety of different geothermal waters from hydrothermal systems across Iceland. Isotope ratios from the high temperature meteoric water recharged systems reflect the isotope ratio of the host rocks without any apparent fractionation. Seawater recharged geothermal systems exhibit more positive δ 1 1B values than the meteoric water recharged geothermal systems. Water/rock ratios can be assessed from boron isotope ratios in the saline hydrothermal systems. Low temperature hydrothermal systems also exhibit more positive δ 1 1B than the high temperature systems, indicating fractionation of boron due to absorption of the lighter isotope onto secondary minerals. Fractionation of boron in carbonate deposits may indicate the level of equilibrium attained within the systems. (author). 14 refs., 2 figs
Mechanisms, timing and quantities of recharge to groundwater in semi-arid and tropical regions
International Nuclear Information System (INIS)
Edmunds, W.M.
2001-01-01
Groundwater being exploited in many and and semi-arid regions at the present day was recharged during former humid episodes of the Pleistocene or Holocene and, in contrast, the amounts derived from modem recharge are small generally small and variable. Geochemical and isotopic techniques provide the most effective way to calculate modem recharge and to investigate recharge history, since physically- based water-balance methods are generally inapplicable in semiarid regions. Examples from Africa (Senegal, Niger, Nigeria, Sudan as well as Cyprus) show that direct recharge rates may vary from zero to around 40% of mean rainfall, dependent primarily on the soil depth and the lithology. Spatial variability presents a real problem in any recharge investigation but results from Senegal show that unsaturated zone profiles may be extrapolated using the chemistry of shallow groundwater. Unsaturated-zone studies show that there are limiting conditions to direct recharge through soil, but that present day replenishment of aquifers takes place via wadis and channels. In the Butana area of central Sudan the regional groundwater was also recharged during a mid-Holocene wet phase and is now in decline. The only current recharge sources, which can be recognised distinctly using stable isotopes, are Nile baseflow and ephemeral wadi floods. (author)
Groundwater Recharge and Flow Processes in Taihang Mountains, a Semi-humid Region, North China
Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie
2015-04-01
Groundwater flow/recharge variations in time and space are crucial for effective water management especially in semi-arid and semi-humid regions. In order to reveal comprehensive groundwater flow/recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were undertaken at 4 times in different seasons (June 2011, August 2012, November 2012, February 2014) in the Wangkuai watershed, Taihang mountains, which is a main groundwater recharge area of the North China Plain. The groundwater, spring, stream water and reservoir water were taken, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate and the depth of groundwater table were observed. The stable isotopic compositions and inorganic solute constituents in the groundwater are depleted and shown similar values as those of the surface water at the mountain-plain transitional area. Additionally, the groundwater in the vicinity of the Wangkuai Reservoir presents clearly higher stable isotopic compositions and lower d-excess than those of the stream water, indicating the groundwater around the reservoir is affected by evaporation same as the Wangkuai Reservoir itself. Hence, the surface water in the mountain-plain transitional area and Wangkuai Reservoir are principal groundwater recharge sources. An inversion analysis and simple mixing model were applied in the Wangkuai watershed using stable isotopes of oxygen-18 and deuterium to construct a groundwater flow model. The model shows that multi-originated groundwater flows from upstream to downstream along topography with certain mixing. In addition, the groundwater recharge occurs dominantly at the altitude from 421 m to 953 m, and the groundwater recharge rate by the Wangkuai Reservoir is estimated to be 2.4 % of the total groundwater recharge in the Wangkuai watershed. Therefore, the stream water and
Energy Technology Data Exchange (ETDEWEB)
Re, V. [Department of Molecular Sciences and Nanosystems, University Ca' Foscari, Venice (Italy); Allais, E. [ISO4 s.n.c., Torino (Italy); El Hamouti, N. [Multidisciplinary Faculty of Nador, University of Oujda, Nador (Morocco); Bouchnan, R. [Laboratory of Physical Phenomena and Natural Risk Modelling, University of Tangier, Tangier (Morocco); Sacchi, E. [Department of Earth Sciences, University of Pavia, Pavia (Italy); Rizzo, F. [UNESCO International Hydrological Programme, Paris (France); Zuppi, G. M. [Department of Molecular Sciences and Nanosystems, University Ca' Foscari, Venice and Institute of Environmental Geology and Geoengineering, National Research Council, Monterotondo (Italy)
2013-07-15
The geochemical and isotopic ({delta}{sup 2}H, {delta}{sup 18}O, {delta}{sup 13}C, {delta}{sup 15}N{sub NO3},{delta} {sup 18}O{sub NO3}) characterization of the Bou Areg aquifer (North Morocco) based on samples collected during two surveys in November 2009 and June 2010 allowed the identification of run-off from the mountain regions and agricultural return flows as the main sources of aquifer recharge. The high salinization of the aquifer is not only due to the intensive agricultural activities but it is also associated with the natural quality of the catchment. The isotopic signal of dissolved nitrates allowed for the identification of two main sources of nitrogen in the system: (i) fertilizers and (ii) manure and septic effluents. The study, framed within the UNESCO-IHP sub component of the Strategic Partnership for the Mediterranean Large Marine Ecosystem, represents the first isotopic investigation of the area and will serve as a basis for the promotion of robust science based management practices in the region. (author)
International Nuclear Information System (INIS)
Awad, M.A.A.; Salem, W.M.; Ezzeldin
1999-01-01
Wadi Gharandal lies on southwestern part of sinai peninsula with its outlets into the Gulf of suez. Eight groundwater samples were collected from quaternary aquifer in wadi gharandal to identify the sources of replenishment and evaluation of its water quality. The variation in chemical composition of water samples is due to water-rock interaction and the effect of sea spray. The distribution of chemical species in the examined groundwater samples is controlled by geography and climate conditions prevailing in the area of study. The salinity increase towards the gulf of suez. The isotopic data indicate that precipitation and floods are considered to be the main sources of recharge in this area. The investigated groundwater samples are found to be suitable for irrigation purposes based on sodium adsorption ratio (SAR) and unsuitable for domestic usages due to high salinity and hardness values
Use of environmental isotopes in arid zone hydrology
International Nuclear Information System (INIS)
Dincer, T.
1980-01-01
After aridity is defined some physical and hydrologic features common in arid lands are described. An attempt has been made to identify various groundwater recharge mechanisms in arid countries and to assess their relative importance. The influence of the arid climates on the isotopic composition of the precipitation is discussed. The use of environmental isotopes in run-off and precipitation infiltration and recharge is evaluated, and the importance of isotopic studies in investigating interrelations between aquifers is stressed. Finally, some examples of isotope applications in surface water and its relation to groundwater are given. (author)
Directory of Open Access Journals (Sweden)
Amol Deshmukh
2018-04-01
Full Text Available Social robots perform tasks to help humans in their daily activities. However, if they fail to fulfill expectations this may affect their acceptance. This work investigates the service degradation caused by recharging, during which the robot is socially inactive. We describe two studies conducted in an ecologically valid office environment. In the first long-term study (3 weeks, we investigated the service degradation caused by the recharging behavior of a social robot. In the second study, we explored the social strategies used to manage users’ expectations during recharge. Our findings suggest that the use of verbal strategies (transparency, apology, and politeness can make robots more acceptable to users during recharge.
Directory of Open Access Journals (Sweden)
Elizabeth Peters
2018-01-01
Full Text Available Mount Shasta (4322 m is famous for its spring water. Water for municipal, domestic and industrial use is obtained from local springs and wells, fed by annual snow melt and sustained perennially by the groundwater flow system. We examined geochemical and isotopic tracers in samples from wells and springs on Mount Shasta, at the headwaters of the Sacramento River, in order to better understand the hydrologic system. The topographic relief in the study area imparts robust signatures of recharge elevation to both stable isotopes of the water molecule (δ18O and δD and to dissolved noble gases, offering tools to identify recharge areas and delineate groundwater flow paths. Recharge elevations determined using stable isotopes and noble gas recharge temperatures are in close agreement and indicate that most snowmelt infiltrates at elevations between 2000 m and 2900 m, which coincides with areas of thin soils and barren land cover. Large springs in Mt Shasta City discharge at an elevation more than 1600 m lower. High elevation springs (>2000 m yield very young water (<2 years while lower elevation wells (1000–1500 m produce water with a residence time ranging from 6 years to over 60 years, based on observed tritium activities. Upslope movement of the tree line in the identified recharge elevation range due to a warming climate is likely to decrease infiltration and recharge, which will decrease spring discharge and production at wells, albeit with a time lag dependent upon the length of groundwater flow paths.
Directory of Open Access Journals (Sweden)
Ziqiang Liu
2018-05-01
Full Text Available Stable isotopes of oxygen and hydrogen were used to estimate seasonal contributions of precipitation to natural spring recharge in Beijing’s mountainous area. Isotopic compositions were shown to be more positive in the dry season and more negative in the wet season, due to the seasonal patterns in the amount of precipitation. The local meteoric water line (LMWL was δ2H = 7.0 δ18O − 2.3 for the dry season and δ2H = 5.9 δ18O − 10.4 for the wet season. LMWL in the two seasons had a lower slope and intercept than the Global Meteoric Water Line (p < 0.01. The slope and intercept of the LMWL in the wet season were lower than that in the dry season because of the effect of precipitation amount during the wet season (p < 0.01. The mean precipitation effects of −15‰ and −2‰ per 100 mm change in the amount of precipitation for δ2H and δ18O, respectively, were obtained from the monthly total precipitation and its average isotopic value. The isotopic composition of precipitation decreased when precipitation duration increased. Little changes in the isotopic composition of the natural spring were found. By employing isotope conservation of mass, it could be derived that, on average, approximately 7.2% of the natural spring came from the dry season precipitation and the rest of 92.8% came from the wet season precipitation.
Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie
2014-05-01
Groundwater recharge is a crucial hydrological process for effective water management especially in arid/ semi-arid regions. However, the insufficient number of specific research regarding groundwater recharge process has been reported previously. Intensive field surveys were conducted during rainy season, mid dry season, and end of dry season, in order to clarify comprehensive groundwater recharge and flow regime of Wangkuai watershed in a headwater, which is a main recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen 18 and deuterium were determined on all water samples. Also the stream flow rate was observed. The solute ion concentrations and stable isotopic compositions show that the most water of this region can be characterized by Ca-HCO3 type and the main water source is precipitation which is affected by altitude effect of stable isotopes. In addition, the river and reservoir of the area seem to recharge the groundwater during rainy season, whereas interaction between surface water and groundwater does not become dominant gradually after the rainy season. The inversion analysis applied in Wangkuai watershed using simple mixing model represents an existing multi-flow systems which shows a distinctive tracer signal and flow rate. In summary, the groundwater recharged at different locations in the upper stream of Wangkuai reservoir flows downward to alluvial fan with a certain amount of mixing together, also the surface water recharges certainly the groundwater in alluvial plain in the rainy season.
Richards, Laura A.; Magnone, Daniel; Boyce, Adrian J.; Casanueva-Marenco, Maria J.; van Dongen, Bart E.; Ballentine, Christopher J.; Polya, David A.
2018-02-01
Chronic exposure to arsenic (As) through the consumption of contaminated groundwaters is a major threat to public health in South and Southeast Asia. The source of As-affected groundwaters is important to the fundamental understanding of the controls on As mobilization and subsequent transport throughout shallow aquifers. Using the stable isotopes of hydrogen and oxygen, the source of groundwater and the interactions between various water bodies were investigated in Cambodia's Kandal Province, an area which is heavily affected by As and typical of many circum-Himalayan shallow aquifers. Two-point mixing models based on δD and δ18O allowed the relative extent of evaporation of groundwater sources to be estimated and allowed various water bodies to be broadly distinguished within the aquifer system. Model limitations are discussed, including the spatial and temporal variation in end member compositions. The conservative tracer Cl/Br is used to further discriminate between groundwater bodies. The stable isotopic signatures of groundwaters containing high As and/or high dissolved organic carbon plot both near the local meteoric water line and near more evaporative lines. The varying degrees of evaporation of high As groundwater sources are indicative of differing recharge contributions (and thus indirectly inferred associated organic matter contributions). The presence of high As groundwaters with recharge derived from both local precipitation and relatively evaporated surface water sources, such as ponds or flooded wetlands, are consistent with (but do not provide direct evidence for) models of a potential dual role of surface-derived and sedimentary organic matter in As mobilization.
International Nuclear Information System (INIS)
Saha, Dipankar; Sinha, U.K.; Dwivedi, S.N.
2011-01-01
Research highlights: → Sub-regional scale aquifers delineated in arsenic-enriched belt in the Ganga Plain. Isotopic fingerprint of the groundwater, from arsenic-enriched and arsenic-safe aquifers established for the first time in the Ganga Plain. → Recharge processes and the water provenances of vertically separated Quaternary aquifers have been established. → Mean residence time of groundwater in the deeper aquifers has been worked out using C-14 isotope. → Water from the deeper aquifer has been correlated with the paleoclimatic model of the Middle Ganga Plain (Mid-Ganga Basin) for 6-2 ka. - Abstract: Arsenic concentrations in groundwater extracted from shallow aquifers in some areas of the Ganga Plain in the states of Bihar and Uttar Pradesh, exceed 50 μg L -1 and locally reach levels in the 400 μg L -1 range. The study covered 535 km 2 of active flood plain of the River Ganga, in Bihar where a two-tier aquifer system has been delineated in a multi-cyclic sequence of Quaternary sand, clay, sandy clay and silty clay all ≤∼250 m below ground surface. The research used isotopic signatures (δ 18 O, δ 2 Η, 3 H, 14 C) and major chemical constituents (HCO 3 - ,SO 4 2- ,NO 3 - ,Cl - ,Ca 2+ ,Mg 2+ ,Na + ,K + ,As total ) of groundwater to understand the recharge processes and groundwater circulation in the aquifers. Values of δ 18 O and δ 2 Η combined with 3 H data indicate that the recharge to the As-enriched top 40 m of the deposits is modern ( -1 ) is hydrologically isolated from the upper aquifer and is characterized by lower 14 C concentration and lower (more negative) δ 18 O values. Groundwater in the lower aquifer is ∼3 ka old, occurs under semi-confined to confined conditions, with hydrostatic head at 1.10 m above the head of the upper aquifer during the pre-monsoon. The recharge areas of the lower aquifer lies in Pleistocene deposits in basin margin areas with the exposed Vindhyan System, at about 55 km south of the area.
Aspects of the environmental isotope chemistry in groundwaters in Eastern Jordan
International Nuclear Information System (INIS)
Lloyd, J.W.
1980-01-01
Aspects of the environmental isotope data from a sandstone and a limestone aquifer are given. The data concerning the sandstone are limited but indicate the type of recharge that is occurring in the outcrop area. Although the 14 C data indicate some modern recharge in radiocarbon terms the tritium data show evidence of only localized recharge. Stable isotope data from one well indicate that indirect recharge may be important. In the limestone aquifer it is found that tritiated groundwater occurs chiefly in the vicinity of wadis indicating the importance of indirect recharge. The lack of tritiated groundwater in the 'recharge mounds' in the interfluve areas is seen as partly a function of sampling but also as indicating the high permeability zones at the tops of the aquifers. The delta 13 C data distribution are examined with respect to possible recharge mechanisms. (author)
Boron isotopes in geothermal systems
International Nuclear Information System (INIS)
Aggarwal, J.
1997-01-01
Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)
California GAMA Special Study: Importance of River Water Recharge to Selected Groundwater Basins
Energy Technology Data Exchange (ETDEWEB)
Visser, Ate [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moran, Jean E. [California State Univ. East Bay (CalState), Hayward, CA (United States); Singleton, Michael J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2016-03-21
River recharge represents 63%, 86% and 46% of modern groundwater in the Mojave Desert, Owens Valley, and San Joaquin Valley, respectively. In pre-modern groundwater, river recharge represents a lower fraction: 36%, 46%, and 24% respectively. The importance of river water recharge in the San Joaquin valley has nearly doubled and is likely the result of a total increase of recharge of 40%, caused by river water irrigation return flows. This emphasizes the importance of recharge of river water via irrigation for renewal of groundwater resources. Mountain front recharge and local precipitation contribute to recharge of desert groundwater basins in part as the result of geological features focusing scarce precipitation promoting infiltration. River water recharges groundwater systems under lower temperatures and with larger water table fluctuations than local precipitation recharge. Surface storage is limited in time and volume, as evidenced by cold river recharge temperatures resulting from fast recharge, compared to the large capacity for subsurface storage. Groundwater banking of seasonal surface water flows therefore appears to be a natural and promising method for increasing the resilience of water supply systems. The distinct isotopic and noble gas signatures of river water recharge, compared to local precipitation recharge, reflecting the source and mechanism of recharge, are valuable constraints for numerical flow models.
Percolation pond as a method of managed aquifer recharge in a ...
Indian Academy of Sciences (India)
8
hydrogeological conditions and the quality of water used for recharge. .... investigate the nature of sediments and the environment of deposition of sediments ...... isotopic signatures and geochemical modelling (unpublished doctoral thesis), ...
Hydro-geochemical and isotopic composition of ground water in Helwan area
Directory of Open Access Journals (Sweden)
W.M. Salem
2015-12-01
The environmental stable isotopes oxygen and hydrogen (18O, and deuterium were studied and used to identify the sources of recharge. The studied ground waters are enriched in D and 18O and the isotopic features suggest that most of the ground water recharged indirectly after evaporation prior to infiltration from irrigation return water as well as the contribution from Nile water.
Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.
2007-01-01
Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed.Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans.Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not
International Nuclear Information System (INIS)
Kohfahl, Claus; Sprenger, Christoph; Herrera, Jose Benavente; Meyer, Hanno; Chacon, Franzisca Fernandez; Pekdeger, Asaf
2008-01-01
The objective of this study is to refine the understanding of recharge processes in watersheds representative for karstic semiarid areas by means of stable isotope analysis and hydrogeochemistry. The study focuses on the Granada aquifer system which is located in an intramontane basin bounded by high mountain ranges providing elevation differences of almost 2900 m. These altitude gradients lead to important temperature and precipitation gradients and provide excellent conditions for the application of stable isotopes of water whose composition depends mainly on temperature. Samples of rain, snow, surface water and groundwater were collected at 154 locations for stable isotope studies (δ 18 O, D) and, in the case of ground- and surface waters, also for major and minor ion analysis. Thirty-seven springs were sampled between 2 and 5 times from October 2004 to March 2005 along an altitudinal gradient from 552 masl in the Granada basin to 2156 masl in Sierra Nevada. Nine groundwater samples were taken from the discharge of operating wells in the Granada basin which are all located between 540 and 728 masl. The two main rivers were monitored every 2-3 weeks at three different altitudes. Rainfall being scarce during the sampling period, precipitation could only be sampled during four rainfall events. Calculated recharge altitudes of springs showed that source areas of mainly snowmelt recharge are generally located between 1600 and 2000 masl. The isotope compositions of spring water indicate water sources from the western Mediterranean as well as from the Atlantic without indicating a seasonal trend. The isotope pattern of the Quaternary aquifer reflects the spatial separation of different sources of recharge which occur mainly by bankfiltration of the main rivers. Isotopic signatures in the southeastern part of the aquifer indicate a considerable recharge contribution by subsurface flow discharged from the adjacent carbonate aquifer. No evaporation effects due to
Energy Technology Data Exchange (ETDEWEB)
Kohfahl, Claus [Freie Universitaet Berlin, Institute of Geological Sciences, Malteserstr. 74-100, D-12249 Berlin (Germany)], E-mail: kohfahl@zedat.fu-berlin.de; Sprenger, Christoph [Freie Universitaet Berlin, Institute of Geological Sciences, Malteserstr. 74-100, D-12249 Berlin (Germany); Herrera, Jose Benavente [Instituto del Agua de la Universidad de Granada, Ramon y Cajal, 4, 18071 Granada (Spain); Meyer, Hanno [Isotope Laboratory of the Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A 43, 14473 Potsdam (Germany); Chacon, Franzisca Fernandez [Dpto. Hidrogeologia y Aguas Subterraneas, Instituto Geologico y Minero de Espana, Oficina de Proyectos, Urb. Alcazar del Genil 4, Edificio Zulema bajo, 18006 Granada (Spain); Pekdeger, Asaf [Freie Universitaet Berlin, Institute of Geological Sciences, Malteserstr. 74-100, D-12249 Berlin (Germany)
2008-04-15
The objective of this study is to refine the understanding of recharge processes in watersheds representative for karstic semiarid areas by means of stable isotope analysis and hydrogeochemistry. The study focuses on the Granada aquifer system which is located in an intramontane basin bounded by high mountain ranges providing elevation differences of almost 2900 m. These altitude gradients lead to important temperature and precipitation gradients and provide excellent conditions for the application of stable isotopes of water whose composition depends mainly on temperature. Samples of rain, snow, surface water and groundwater were collected at 154 locations for stable isotope studies ({delta}{sup 18}O, D) and, in the case of ground- and surface waters, also for major and minor ion analysis. Thirty-seven springs were sampled between 2 and 5 times from October 2004 to March 2005 along an altitudinal gradient from 552 masl in the Granada basin to 2156 masl in Sierra Nevada. Nine groundwater samples were taken from the discharge of operating wells in the Granada basin which are all located between 540 and 728 masl. The two main rivers were monitored every 2-3 weeks at three different altitudes. Rainfall being scarce during the sampling period, precipitation could only be sampled during four rainfall events. Calculated recharge altitudes of springs showed that source areas of mainly snowmelt recharge are generally located between 1600 and 2000 masl. The isotope compositions of spring water indicate water sources from the western Mediterranean as well as from the Atlantic without indicating a seasonal trend. The isotope pattern of the Quaternary aquifer reflects the spatial separation of different sources of recharge which occur mainly by bankfiltration of the main rivers. Isotopic signatures in the southeastern part of the aquifer indicate a considerable recharge contribution by subsurface flow discharged from the adjacent carbonate aquifer. No evaporation effects due
Bourke, Sarah A.; Cook, Peter G.; Dogramaci, Shawan; Kipfer, Rolf
2015-06-01
Groundwater recirculation occurs when groundwater is pumped from an aquifer onto the land surface, and a portion of that water subsequently infiltrates back to the aquifer. In environments where groundwater is recirculated, differentiation between various sources of recharge (e.g. natural rainfall recharge vs. recirculated water) can be difficult. Groundwater age indicators, in particular transient trace gases, are likely to be more sensitive tracers of recharge than stable isotopes or chloride in this setting. This is because, unlike stable isotopes or chloride, they undergo a process of equilibration with the atmosphere, and historical atmospheric concentrations are known. In this paper, groundwater age indicators (14C and CFC-12) were used as tracers of recharge by surplus mine water that is discharged to streams. Ternary mixing ratios were calculated based on 14C and CFC-12 concentrations measured along three transects of piezometers and monitoring wells perpendicular to the creeks, and from dewatering wells. Uncertainty in calculated mixing ratios was estimated using a Monte Carlo approach. Ternary mixing ratios in dewatering wells suggest that recharge by mine water accounted for between 10% and 87% of water currently abstracted by dewatering wells. The calculated mixing ratios suggest that recharge by mine water extends to a distance of more than 550 m from the creeks. These results are supported by seepage flux estimates based on the water and chloride balance along the creeks, which suggest that 85-90% of mine water discharged to the creeks recharges the aquifer and recharge by mine water extends between 110 and 730 m from the creeks. Mixing calculations based on gaseous groundwater age indicators could also be used to partition recharge associated with agricultural irrigation or artificial wetland supplementation.
Application of isotope study of the hydrogeological aquifers of the Yarmouk basin
International Nuclear Information System (INIS)
Sharida, A.R.; Jubeili, Y.
2001-05-01
Environmental isotopic variations have been used to investigate the source of recharge and age in the basaltic and deep limestone aquifers system in the Yarmouk basin, SW of Syria. Isotopic results show that recharge of basaltic aquifer is directly related to infiltration of rainwater from high and transitional zones. However, the homogeneity noted of stable and radioactive isotopes values (δ 18 O= -5.58± 0.25%, 14 C=46.2± 4.45 % pmc) in Laja plateau and central zone, confirm the mechanism of common recharge and critical role of this plateau in absorbing great amount of precipitation. In addition these values indicate, to a high rate mixing taking place in this plateau and the central zone. In the Kahiel area, the groundwater is of recent age as shown from the high values of 14 C activity ( 14 C= 66.3 ± 5.3 % pcm) accompanied by enriched 18 O (δ 18 O=-4.7±0.22 %). The recharge of groundwater is related to the leakage of water from dams and drainage network. The tectonic setting in this area constitutes an additional factor in increasing this recharge. Netpath model was used to determine the age of groundwater. the age of groundwater in the basaltic aquifer is generally modern and reaches 2000 y BP in discharge area. Preliminary conclusion of deep limestone aquifer, indicate that its groundwater occur under high piezometric pressure. The salinity is less than 1g/L and the temperature water varied between 35 to 45 degreed centigrade. The low 14 C activities in deep groundwater suggest pleistocene and holocene recharge, although their stable isotopes values indicate recharge by modern meteoric precipitation. The corrected age of this groundwater determined by Netpath model indicate that this age fall between recent water in recharge area and 20 Ky BP. (author)
International Nuclear Information System (INIS)
McNab, Walt W.; Singleton, Michael J.; Moran, Jean E.; Esser, Bradley K.
2009-01-01
Stable isotope data, a dissolved gas tracer study, groundwater age dating, and geochemical modeling were used to identify and characterize the effects of introducing low-TDS recharge water in a shallow aerobic aquifer affected by a managed aquifer recharge project in California's San Joaquin Valley. The data all consistently point to a substantial degree of mixing of recharge water from surface ponds with ambient groundwater in a number of nearby wells screened at depths above 60 m below ground surface. Groundwater age data indicate that the wells near the recharge ponds sample recently recharged water, as delineated by stable O and C isotope data as well as total dissolved solids, in addition to much older groundwater in various mixing proportions. Where the recharge water signature is present, the specific geochemical interactions between the recharge water and the aquifer material appear to include ion exchange reactions (comparative enrichment of affected groundwater with Na and K at the expense of Ca and Mg) and the desorption of oxyanion-forming trace elements (As, V, and Mo), possibly in response to the elevated pH of the recharge water
Vystavna, Yuliya; Diadin, Dmytro; Huneau, Frédéric
2018-05-01
Stable isotopes of hydrogen ( 2 H) and oxygen ( 18 O) of the water molecule were used to assess the relationship between precipitation, surface water and groundwater in a large Russia/Ukraine trans-boundary river basin. Precipitation was sampled from November 2013 to February 2015, and surface water and groundwater were sampled during high and low flow in 2014. A local meteoric water line was defined for the Ukrainian part of the basin. The isotopic seasonality in precipitation was evident with depletion in heavy isotopes in November-March and an enrichment in April-October, indicating continental and temperature effects. Surface water was enriched in stable water isotopes from upstream to downstream sites due to progressive evaporation. Stable water isotopes in groundwater indicated that recharge occurs mainly during winter and spring. A one-year data set is probably not sufficient to report the seasonality of groundwater recharge, but this survey can be used to identify the stable water isotopes framework in a weakly gauged basin for further hydrological and geochemical studies.
International Nuclear Information System (INIS)
Bredenkamp, D.B.
1978-01-01
Methods of quantitative estimation of groundwater recharge have been estimated to 1) illustrate uncertainties associated with methods usually applied 2) indicate some of the simplifying assumptions inherent to a specific method 3) propagate the use of more than one technique in order to improve the reliability of the combined recharge estimate and 4) propose a hydrological model by which the annual recharge and annual variability of recharge could be ascertained. Classical methods such as the water balance equation and flow nets have been reviewed. The use of environmental tritium and radiocarbon have been illustrated as a means of obaining qualitative answers to the occurence of recharge and in revealing the effective mechanism of groundwater recharge through the soil. Quantitative estimation of recharge from the ratio of recharge to storage have been demonstrated for the Kuruman recharge basin. Methods of interpreting tritium profiles in order to obtain a quantitative estimate of recharge have been shown with application of the technique for Rietondale and a dolomitic aquifer in the Western Transvaal. The major part of the thesis has been devoted to the use of hydrological model as a means of estimating groundwater recharge. Subsequent to a general discussion of the conceptual logic, various models have been proposed and tested
Groundwater geochemistry of nile delta-desert interface 1.isotope hydrology
International Nuclear Information System (INIS)
Hussein, M.F.; Nada, A.A.; Awad, M.A.
1995-01-01
Sustenance and environmental protection of groundwater supply is of major concern in the integral environmental development in the arid to sub-arid regions in the Nile basin. Isotope data ( 18O , 2H and 3H ) of groundwater in the west of the Nile delta indicates the contribution of palaeo groundwater component (in the range 0.1 - 0.8 with means of 0.39 and 0.52 for tahrir and khatatbah, respectively) along with sub recent recharge from the delta aquifer and recent recharge from irrigation conveyance canals in desert. Isotope mixing model (developed as Two-input table using excel TM spreads heat on apple Macintosh TM) is proposed to explain the apparent discrepancies in groundwater isotopic composition of khatatbah and tahrir areas assuming the contribution of two isotopically different palaeo-oples with two isotopically similar maind delta groundwater poles. About 0.30% 1 8 O depletion per 10 Km downstream is detected and low northward groundwater recharge is suggested along 75 Km of the western strip of rosetta Nile. Higher sub-recent recharge from the main delta aquifer is believed to take place in khatatbah than tahrir whereas the last is believed to be replenished at present from the irrigation/ drainage network and irrigated fields with higher pollution risk for groundwater system in tahrir aquifer is exposed to northern marine intrusion. Lowering of the piezo metric level is to be expected in the newly exploited desertic areas under over pumping. 9 figs
Kallioras, Andreas; Piepenbrink, Matthias; Schuth, Christoph; Pfletschinger, Heike; Dietrich, Peter; Koeniger, Franz; Rausch, Randolf
2010-05-01
Accurate determination of groundwater recharge is a key issue for the "smart mining" of groundwater resources. Groundwater recharge estimation techniques depend on the investigated hydrologic zone, and therefore main approaches are based on (a) unsaturated zone, (b) saturated zone and (c) surface water studies. This research contributes to the determination of groundwater recharge by investigating the infiltration of groundwater through the unsaturated zone. The investigations are conducted through the application of a combination of different pilot field as well as lab techniques. The field techniques include the installation of specially designed Time Domain Reflectometry (TDR) sensors, at different depths within the unsaturated zone for in-situ and continuous measurements of the volumetric pore water content. Additionally, the extraction of pore water -for analysis of its isotopic composition- from multilevel undisturbed soil samples through significant depths within the unsaturated zone column, enables the dating of the groundwater age through the determination of its isotopic composition. The in-situ investigation of the unsaturated zone is complemented by the determination of high resolution temperature profiles. The installation of the pilot TDR sensors is achieved by using direct push methods at significant depths within the unsaturated zone, providing continuous readings of the soil moisture content. The direct push methods are also ideal for multilevel sampling of undisturbed -without using any drilling fluids which affect the isotopic composition of the containing pore water- soil and consequent extraction of the included pore water for further isotopic determination. The pore water is extracted by applying the method of azeotropic distillation; a method which has the least isotopic fractionation effects on groundwater samples. The determination of different isotopic signals such as 18O, 2H, 3H, and 36Cl, aims to the investigation of groundwater transit
International Nuclear Information System (INIS)
Gates, John B; Edmunds, W Mike; Darling, W George; Ma Jinzhu; Pang Zhonghe; Young, Adam A
2008-01-01
Sources of groundwater recharge to the Badain Jaran Desert in China have been investigated using geochemical and isotopic techniques. Stable isotope compositions (δ 18 O and δ 2 H) of shallow groundwater and surface water from oasis lakes evolve from a starting composition considerably depleted compared to local unsaturated zone moisture, confirming inferences from chloride mass balance that direct infiltration of precipitation is not a volumetrically important source of recharge to the shallow aquifer in the study area. Shallow phreatic and deeper confined groundwater bodies appear unconnected based on chemical composition and radiocarbon activities. Hydrogeologic evidence points toward a bordering mountain range (Yabulai) as a likely recharge zone, which is consistent with tracer results. A mean residence time in the range of 1-2 ka for the desert's southeastern margin is inferred from radiocarbon. These results reveal that some replenishment to the desert aquifer is occurring but at a rate much lower than previously suggested, which is relevant for water resources planning in this ecologically sensitive area
GAMA-LLNL Alpine Basin Special Study: Scope of Work
Energy Technology Data Exchange (ETDEWEB)
Singleton, M J; Visser, A; Esser, B K; Moran, J E
2011-12-12
For this task LLNL will examine the vulnerability of drinking water supplies in foothills and higher elevation areas to climate change impacts on recharge. Recharge locations and vulnerability will be determined through examination of groundwater ages and noble gas recharge temperatures in high elevation basins. LLNL will determine whether short residence times are common in one or more subalpine basin. LLNL will measure groundwater ages, recharge temperatures, hydrogen and oxygen isotopes, major anions and carbon isotope compositions on up to 60 samples from monitoring wells and production wells in these basins. In addition, a small number of carbon isotope analyses will be performed on surface water samples. The deliverable for this task will be a technical report that provides the measured data and an interpretation of the data from one or more subalpine basins. Data interpretation will: (1) Consider climate change impacts to recharge and its impact on water quality; (2) Determine primary recharge locations and their vulnerability to climate change; and (3) Delineate the most vulnerable areas and describe the likely impacts to recharge.
Groundwater recharge and flow on Montserrat, West Indies: Insights from groundwater dating
Hemmings, Brioch; Gooddy, Daren; Whitaker, Fiona; George Darling, W.; Jasim, Alia; Gottsmann, Joachim
2015-01-01
Study region Montserrat, Lesser Antilles, Caribbean. Study focus Analysis of δ2H and δ18O isotopes, and chlorofluorocarbon (CFC) anthropogenic tracers in Montserrat groundwater provides insights into the age and provenance of the spring waters. New hydrological insights δ2H and δ18O analysis indicates uniform recharge elevations for groundwaters on Montserrat. CFC-11 and CFC-12 analysis reveals age differences between isotopically similar, high elevation springs and low eleva...
Groundwater recharge and agricultural contamination
Böhlke, J.K.
2002-01-01
Agriculture has had direct and indirect effects on the rates and compositions of groundwater recharge and aquifer biogeochemistry. Direct effects include dissolution and transport of excess quantities of fertilizers and associated materials and hydrologic alterations related to irrigation and drainage. Some indirect effects include changes in water–rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3–, N2, Cl, SO42–, H+, P, C, K, Mg, Ca, Sr, Ba, Ra, and As, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3–, a combination of chemical, isotopic, and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. Groundwater records derived from multi-component hydrostratigraphic data can be used to quantify recharge rates and residence times of water and dissolved contaminants, document past variations in recharging contaminant loads, and identify natural contaminant-remediation processes. These data indicate that many of the world's surficial aquifers contain transient records of changing agricultural contamination from the last half of the 20th century. The transient agricultural groundwater signal has important implications for long-term trends and spatial heterogeneity in discharge.
International Nuclear Information System (INIS)
Al-Charideh, A.
2002-01-01
Environmental isotopic variations have been used to investigate the source of recharge and age in the basaltic and deep limestone aquifers system in the Yarmouk basin, SW of Syria. Isotopic results show that recharge of basaltic aquifer is directly related to infiltration of rainwater from high and transitional zones. However, the homogeneity noted of stable and radioactive isotopes values (δ 18 O= -5.58± 0.25%, 14 C=46.2± 4.45 % pmc) in Laja plateau and central zone, confirm the mechanism of common recharge and critical role of this plateau in absorbing great amount of precipitation. In addition these values indicate, to a high rate mixing taking place in this plateau and the central zone. In the Kahiel area, the groundwater is of recent age as shown from the high values of 14 C activity ( 14 C= 66.3 ± 5.3 % pcm) accompanied by enriched 18 O (δ 18 O=-4.7±0.22 %). The recharge of groundwater is related to the leakage of water from dams and drainage network. The tectonic setting in this area constitutes an additional factor in increasing this recharge. Netpath model was used to determine the age of groundwater. the age of groundwater in the basaltic aquifer is generally modern and reaches 2000 y BP in discharge area. Preliminary conclusion of deep limestone aquifer, indicate that its groundwater occur under high piezometric pressure. The salinity is less than 1g/L and the temperature water varied between 35 to 45 degreed centigrade. The low 14 C activities in deep groundwater suggest pleistocene and holocene recharge, although their stable isotopes values indicate recharge by modern meteoric precipitation. The corrected age of this groundwater determined by Netpath model indicate that this age fall between recent water in recharge area and 20 Ky BP. (author)
Groundwater geochemistry of nile delta-desert interface 1.isotope hydrology
Energy Technology Data Exchange (ETDEWEB)
Hussein, M F [Cairo University, Dept., of Soil and water, Giza, Gamma Street, (Egypt); Nada, A A; Awad, M A [Atomic Energy Authority, Nuclear Chemistry Dept., P.o. Box 13759, Cairo, (Egypt)
1995-10-01
Sustenance and environmental protection of groundwater supply is of major concern in the integral environmental development in the arid to sub-arid regions in the Nile basin. Isotope data ({sup 18O}, {sup 2H} and {sup 3H}) of groundwater in the west of the Nile delta indicates the contribution of palaeo groundwater component (in the range 0.1 - 0.8 with means of 0.39 and 0.52 for tahrir and khatatbah, respectively) along with sub recent recharge from the delta aquifer and recent recharge from irrigation conveyance canals in desert. Isotope mixing model (developed as Two-input table using excel{sup TM} spreads heat on apple Macintosh{sup TM)} is proposed to explain the apparent discrepancies in groundwater isotopic composition of khatatbah and tahrir areas assuming the contribution of two isotopically different palaeo-oples with two isotopically similar maind delta groundwater poles. About 0.30% {sup 1}8{sup O} depletion per 10 Km downstream is detected and low northward groundwater recharge is suggested along 75 Km of the western strip of rosetta Nile. Higher sub-recent recharge from the main delta aquifer is believed to take place in khatatbah than tahrir whereas the last is believed to be replenished at present from the irrigation/ drainage network and irrigated fields with higher pollution risk for groundwater system in tahrir aquifer is exposed to northern marine intrusion. Lowering of the piezo metric level is to be expected in the newly exploited desertic areas under over pumping. 9 figs.
Isotope hydrology of ground waters of the Kalahari, Gordonia
International Nuclear Information System (INIS)
Verhagen, B.Th.
1985-01-01
Environmental isotope observations were conducted on ground waters from approximately 50 boreholes covering a substantial part of Gordonia. The quality of these waters ranges from fresh to saline. The observed isotope ratios cover a wide range of values, indicating varied hydrological conditions. The most important conclusions arrived at by this study are: 1. no important regional movement of ground water occurs at present; 2. there is widespread evidence of diffuse rainfall recharge; and 3. an important part of ground-water salinity is derived from the unsaturated zone, during such recharge
Temporal variations of isotopes in arid rain storms
International Nuclear Information System (INIS)
Adar, E.M.; Dodi, A.; Geyh, M.A.; Yair, A.
1999-01-01
The distribution of isotopes in rainfall has long been used to elaborate on hydrological systems. Both isotopic composition of stable isotopes (oxygen-18 and deuterium) and tritium content are used to illuminate on sources of groundwater recharge and as tracers upon which groundwater fluxes are assessed. As runoff is concerned, stable isotopes have been used to identify flow paths and the precise location of the rain storm which produced the floods. Analyses of stable isotopes in arid storms in the Negev desert revealed clear discrepancy between the spatial isotopic composition in floods versus the spatial and temporal isotopic composition in rainfall. In addition, simple water balance revealed that the entire flood volume is equivalent to a very small portion of the rain storm, suggesting that a specific flood is produced by a very short and intensive portion of the rainfall. Therefore, knowledge of the weighted isotopic average of a rainfall can not serve as an adequate input function for modeling of desert floods. Since in arid environment, floods are considered as major source of groundwater recharge it also can not be used as input function for modeling of groundwater systems. This paper summarizes detailed isotopic study of short segments (∼2 mm each) of desert rainstorms as sampled in the Negev desert, Israel
International Nuclear Information System (INIS)
Herczeg, A.L.; Rattray, K.J.; Dillon, P.J.; Pavelic, P.C.; Barry, K.J.
2002-01-01
Artificial recharge and reclamation of stormwater into groundwater is a newly developing strategy to augment water resources in the Adelaide metropolitan area of South Australia. Mixing between injected storm water and native groundwater can be most effectively using naturally occurring chloride ion. Stable isotopes of the water molecule are used more effectively during short term tests (i.e., immediately following injection events), and requires frequent monitoring of the surface water end-member. Biogeochemical processes involving geochemical reactions such as organic matter oxidation, carbonate mineral dissolution and sulfide mineral oxidation are very effectively traced by δ 13 C and 14 C (of TDIC) and δ 34 S (of SO 4 2- ). The most important processes occurring in the Tertiary limestone aquifer in Adelaide were carbonate mineral dissolution which is induced largely by CO 2 production during organic matter oxidation. Sulfide mineral oxidation is a minor process, and is accompanied by an equivalent amount of sulfate reduction after injection of the stormwater. (author)
An approach to identify urban groundwater recharge
Directory of Open Access Journals (Sweden)
E. Vázquez-Suñé
2010-10-01
Full Text Available Evaluating the proportion in which waters from different origins are mixed in a given water sample is relevant for many hydrogeological problems, such as quantifying total recharge, assessing groundwater pollution risks, or managing water resources. Our work is motivated by urban hydrogeology, where waters with different chemical signature can be identified (losses from water supply and sewage networks, infiltration from surface runoff and other water bodies, lateral aquifers inflows, .... The relative contribution of different sources to total recharge can be quantified by means of solute mass balances, but application is hindered by the large number of potential origins. Hence, the need to incorporate data from a large number of conservative species, the uncertainty in sources concentrations and measurement errors. We present a methodology to compute mixing ratios and end-members composition, which consists of (i Identification of potential recharge sources, (ii Selection of tracers, (iii Characterization of the hydrochemical composition of potential recharge sources and mixed water samples, and (iv Computation of mixing ratios and reevaluation of end-members. The analysis performed in a data set from samples of the Barcelona city aquifers suggests that the main contributors to total recharge are the water supply network losses (22%, the sewage network losses (30%, rainfall, concentrated in the non-urbanized areas (17%, from runoff infiltration (20%, and the Besòs River (11%. Regarding species, halogens (chloride, fluoride and bromide, sulfate, total nitrogen, and stable isotopes (18O, 2H, and 34S behaved quite conservatively. Boron, residual alkalinity, EDTA and Zn did not. Yet, including these species in the computations did not affect significantly the proportion estimations.
The isotope altitude effect reflected in groundwater: a case study from Slovenia.
Mezga, Kim; Urbanc, Janko; Cerar, Sonja
2014-01-01
This paper presents the stable isotope data of oxygen (δ(18)O) and hydrogen (δ(2)H) in groundwater from 83 sampling locations in Slovenia and their interpretation. The isotopic composition of water was monitored over 3 years (2009-2011), and each location was sampled twice. New findings on the isotopic composition of sampled groundwater are presented, and the data are also compared to past studies regarding the isotopic composition of precipitation, surface water, and groundwater in Slovenia. This study comprises: (1) the general characteristics of the isotopic composition of oxygen and hydrogen in groundwater in Slovenia, (2) the spatial distribution of oxygen isotope composition (δ(18)O) and d-excess in groundwater, (3) the groundwater isotope altitude effect, (4) the correlation between groundwater d-excess and the recharge area altitude of the sampling location, (5) the relation between hydrogen and oxygen isotopes in groundwater in comparison to the global precipitation isotope data, (6) the groundwater isotope effect of distance from the sea, and (7) the estimated relation between the mean temperature of recharge area and δ(18)O in groundwater.
International Nuclear Information System (INIS)
Ma Jinzhu; Pan Feng; Chen Lihua; Edmunds, W. Mike; Ding Zhenyu; He Jianhua; Zhou Kunpeng; Huang Tianming
2010-01-01
Multiple isotopic and hydrogeochemical tracers were utilized to understand the recharge sources and geochemical evolution of groundwater in the Quaternary aquifer beneath Jinchang city and the adjacent Gobi desert area. The groundwater shows markedly depleted stable isotopic composition compared to modern rainfall. The signature of groundwaters from Jinchang and the northern Gobi desert area differ clearly from that of the alluvial fan in the south Yongchang basin and modern rainfall, and has lower or non-detectable 3 H activity, implying that the aquifer is likely maintained by palaeowater. This groundwater in the Gobi desert has a 14 C age older than 12 ka, indicating that the groundwater resources are non-renewable. The build-up of dissolved solids through evaporation is a major control on groundwater composition, and the dominant anion species change systematically from HCO 3 - , SO 4 2- to Cl - , but cations from weathering of albite, calcite, dolomite and gypsum also make a significant contribution. The scientific results have important implications for groundwater management in Jinchang city and as well as in the Shiyang River basin under China's West Development Strategy. It is recommended that the water allocation program of diverting water from the Dongda river to the Minqin basin be reconsidered.
Water quality management of aquifer recharge using advanced tools.
Lazarova, Valentina; Emsellem, Yves; Paille, Julie; Glucina, Karl; Gislette, Philippe
2011-01-01
Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.
Hydrochemical and Isotopic Assessment of Ground Water in Eastern Desert, Egypt
International Nuclear Information System (INIS)
Atiti, S.Y.; Ali, M.M.; Yousef, L.A.; Dessouki, H.A.
2011-01-01
The recharge rate is the most critical factor to ground water resources especially in semi- arid and arid areas. Fourteen representative ground water samples were collected from South Eastern Desert of Egypt and subjected to chemical and isotopic composition. The chemical data reported that, the alkalinity (ph) ranges between 6.5 and 8.5, the salinity of water ranges between 396 and 7874 ppm, sodium is the most dominant cation and chloride is the most dominant anion. The concentration of trace elements (Fe, Pb, Cd, Ni, Cu, Zn, and Mn) was analyzed to evaluate the suitability for drinking and irrigation. Uranium and thorium concentrations were found within the safe limit. Most of ground water was found suitable for drinking water, laundry, irrigation, building, industrial, livestock and poultry. The environmental stable isotopes (D and 18 O) and the radioactive isotope 3 H were evaluated for water samples of the investigated area to focus on the origin of the ground water, sources of recharging and the water rock interaction between aquifers and water. The isotopic compositions of these ground water samples indicated that, there are three different sources of recharge; paleo-water, local precipitation and rain water
Application of stable isotopes to hydrogeology in coal mine
International Nuclear Information System (INIS)
Duan Qi; Duan Yucheng
1988-01-01
Stable isotopes including Oxygen-18 and Deuterium have been applied to investigation of hydrogeology in main coal mines. By determination of stable isotopic composition of hydrogen and oxygen together with water analysis, the following studies have been developed: Identification of the hydrogeochemical characteristics of the groundwater from varied aquifers; Analysis of the hydraulic relationship between varied aquifers; Interpretation of the probable recharge source of mine water. The research results mentioned above reveal that: 1. The groundwater from main aquifers at coal mines in north China is of meteoric origin, which is recharged from hilly area surrounding the coal mine. Its isotopic composition differs slightly from that of the local precipitation. 2. There is a mutual hydraulic relationship between the Ordovician and Quarternary aquifers, so the difference of isotopic composition is very small. 3. By way of the variation of isotopic composition of groundwater from coal-bearing strata, we can infer the hydraulic relationship extent between overlaid alluvial layer and underlaid Ordovician limestone. (author). 9 refs, 6 figs, 8 tabs
DEFF Research Database (Denmark)
Larsen, Flemming; Owen, R.; Dahlin, T.
2002-01-01
A multi-disciplinary study is being carried out on recharge to the Karoo sandstone aquifer in the western part of Zimbabwe, where recharge is controlled by the presence of a thick, confining basalt layer. The aquifer is geographically extensive, and has been identified throughout the southern part......, before it dips below an impervious basalt cover. However, resistivity profiling shows that the basalt at the basin margin is weathered and fractured, and probably permeable, while the basalt deeper into the basin is fresh, solid and impermeable. Field and laboratory analysis of 22 groundwater samples......–130 mm/yr, with an average value of 25 mm/yr. Preliminary results of recharge estimate using 36Cl data suggests lower direct infiltration rates, but further studies are needed. The combination of hydro-chemical, isotopic and geophysical investigations show that the recharge area extends well beyond...
Kalahari groundwaters: Their hydrogen, carbon and oxygen isotopes
International Nuclear Information System (INIS)
Mazor, E.; Verhagen, B.T.; Sellschop, J.P.F.; Robins, N.S.; Hutton, L.G.
1974-01-01
Tritium and 14 C measurements have revealed several cases of post-nuclear bomb-test rain recharge of local groundwaters, along with values indicating recharge over larger, yet hydrologically active, time scales. In general, recharge seems to follow rain distribution in being more intense in the northern rather than in the southern Kalahari. Initial δ 13 C values vary over a wide range and reveal some correlation to pH and chemical composition of the water. They cannot be used to correct for fossil carbon dilution in 14 C-age calculations. Radiocarbon-deduced ages range from recent to 30,000 years. Stable hydrogen and oxygen isotopes indicate recharge from direct rain infiltration. (author)
Tritium profiles in Kalahari sands as a measure of rain water recharge
International Nuclear Information System (INIS)
Verhagen, B.T.; Smith, P.E.; McGeorge, I.; Dziembowski, Z.
1978-01-01
This paper attempts to relate recharge measurements in the Kalahari by tritium profiles in the unsaturated zone to isotopic, hydrochemical and hydrologic data from an underlying, semi-confined aquifer. Auger holes into the sand cover were drilled along a line of experimental deeper holes penetrating the saturated zone. A further line of auger holes was drilled into the dune sand cover of a control area. Variable moisture contents, apparently indepent of grain size distribution and indicating transients are observed in the different profiles. 3 H and 18 O measurements on the moisture contents allow for the identification of the 1962/63 bomb tritium rise and successive drier and wetter periods. Infiltration, or potential recharge as percentage of infiltration was found to be strongly dependent on the annual rainfall. The distribution of 14 C, 13 C, 3 H and chemistry in the shallower of two underlying aquifers leads to the consideration of three possible mechanisms of recharge. Arguments favouring vertical recharge are presented, which lead to possible extrapolations into the sand covered areas of the Kalahari in general. (orig.) [de
Stamm, John F.; McBride, W. Scott
2016-12-21
Discharge from springs in Florida is sourced from aquifers, such as the Upper Floridan aquifer, which is overlain by an upper confining unit that locally can have properties of an aquifer. Water levels in aquifers are affected by several factors, such as precipitation, recharge, and groundwater withdrawals, which in turn can affect discharge from springs. Therefore, identifying groundwater sources and recharge characteristics can be important in assessing how these factors might affect flows and water levels in springs and can be informative in broader applications such as groundwater modeling. Recharge characteristics include the residence time of water at the surface, apparent age of recharge, and recharge water temperature.The groundwater sources and recharge characteristics of three springs that discharge from the banks of the Suwannee River in northern Florida were assessed for this study: Bell Springs, White Springs, and Suwannee Springs. Sources of groundwater were also assessed for a 150-foot-deep well finished within the Upper Floridan aquifer, hereafter referred to as the UFA well. Water samples were collected for geochemical analyses in November 2012 and October 2013 from the three springs and the UFA well. Samples were analyzed for a suite of major ions, dissolved gases, and isotopes of sulfur, strontium, oxygen, and hydrogen. Daily means of water level and specific conductance at White Springs were continuously recorded from October 2012 through December 2013 by the Suwannee River Water Management District. Suwannee River stage at White Springs was computed on the basis of stage at a U.S. Geological Survey streamgage about 2.4 miles upstream. Water levels in two wells, located about 2.5 miles northwest and 13 miles southeast of White Springs, were also used in the analyses.Major ion concentrations were used to differentiate water from the springs and Upper Floridan aquifer into three groups: Bell Springs, UFA well, and White and Suwannee Springs. When
Directory of Open Access Journals (Sweden)
Tagma, T.
2008-06-01
Full Text Available Determination of the origin of recharge of the unconfined aquifer in the right side of the Souss wadi between Agadir and Taroudant (South-western of Morocco was based on the use of hydrochemical and isotopic analysis of groundwater, surface water and springs of the contact zone between the High-Atlas Chain and the Souss plain.The correspondence in the space evolution of the various chemical elements of evaporitic origin (SO42-, Cl-, Sr2+ in groundwater, piedmont springs, and surface water reveals the existence of recharge water from the adjacent High-Atlas Chain.The various recharge modes of the different aquifers (High Atlas and Souss plain determined by isotopic analysis, shows that the source of groundwater for the unconfined Souss aquifer seems to be composite between a direct infiltration on the High-Atlas tributaries and a remote recharge from the bordering High Atlas aquifers.La determinación del origen de los aportes de agua de la capa freática de la ribera derecha del rio Souss entre Agadir y Taroudant (Suroeste de Marruecos se ha basado en la hidroquímica y el análisis isotópico de las aguas subterráneas, aguas superficiales y manantiales de la zona de contacto entre el Alto Atlas y la llanura de Souss.La correspondencia en la evolución espacial de los diferentes elementos químicos de origen evaporítico (SO42-, Cl-, Sr2+ en las aguas subterráneas, manantiales de pie de monte y aguas superficiales, revela la existencia de una recarga de agua procedente de la cadena del Alto Atlas. El análisis de los modos de recarga de los diferentes acuíferos (Alto Atlas y llanura de Souss determinado por análisis isotópico, demuestra que la alimentación de la capa freática de Souss a partir del Alto Atlas parece ser mixta, compuesta por una infiltración directa de los afluentes del Alto Atlas y una alimentación lejana desde los acuiferos que limitan con el borde del Alto Atlas.
Use of environmental isotopes in hydrogeological studies in Kedah and Perlis, Malaysia
International Nuclear Information System (INIS)
Daud bin Mohamad.
1981-01-01
A preliminary study of the isotope hydrology of the Kedah and Perlis area was undertaken under the RCA programme. This project is an attempt at elucidating the mechanism of recharge, origin, area of recharge and dating of groundwater system in the area. The results show that all groundwater samples in the area vary within a narrow range for 18 0 (-7.58 to -5.06%) while 2 H ranges from -50.3 to -35.1%. The mean isotopic composition of precipitation collected at Alor Star meteorological station fall within the range of variation of the Kedah/Perlis groundwaters. In the southern part of the study site, the isotopic results indicate the occurence of two types of water; firstly the recharge is from the highlands where more negative 18 0 values and low tritium were observed and the second type is of local recharge where high tritium and less negative 18 0 values were observed. On the other hand, in the northern part of the basin the interpretation of stable isotopic results is quite difficult to be made at this stage. There was no correlation at all between tritium and 18 0 whatsoever. Results of the tritium assay show that some of the groundwater samples are pre-nuclear in age as indicated by low tritium content. Consequently, a Carbon-14 investigation was carried out from a few selected sites and their ages were found to be in the range of about 3000 to 5000 years. (author)
International Nuclear Information System (INIS)
2004-01-01
Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near the western margin of the Hanford Site, and ambient drainage may be up to 30 mm/yr in the center of the site assuming an average bulk rock weathering rate of 10-7.5 g/g/yr
International Nuclear Information System (INIS)
Nada, A.A.; Awad, M.A.; Froehlich, K.; El Behery, M.
1991-01-01
Groundwater samples collected from a number of localities, in Al-Maghara area, north central part of Sinai, were subject to various chemical and isotopic analysis. The purpose of the study is to determine whether the groundwaters are recently recharged or not in order to adopt an efficient water management policy. The hydrochemical results indicate that they are mainly of primary marine origin, dilution of this water by meteoric water changes its chemical composition to be mixed water type, which has the major chemical components: KCl, NaCl, Na 2 SO 4 , MgSO 4 , Mg(HCO 3 ) 2 and Ca(HCO 3 ) 2 . The tritium content confirm the meteoric water recharge recently especially for wells with high tritium content. The stable environmental isotopic composition of the groundwater reflects the isotopic composition of precipitation and flooding with some evaporation enrichment prior to infiltration. There is also mixing with palaeowater (water recharge in the past cooler climate periods), by leaking through faulting in the area. (orig.) [de
Rechargeable sup(99)MO/sup(99m)TC generator system
International Nuclear Information System (INIS)
Thornton, A.K.; Cerone, F.E.
1980-01-01
A rechargeable radioisotope generator system is described in which the transfer of the parent isotope, molybdenum 99, can be affected safely and easily. Part of the system consists of a shielded shipping vial for the parent isotope. The generator consists of an alumina column upon which molybdenum 99 may be adsorbed and from which technetium 99m may be eluted. The generator is shipped as a cold package to the user and is charged as needed. A transfer mechanism is incorporated in the shipping shield, which allows the septum of the vial to be pierced and the contents to be transferred to the generator essentially automatically. (LL)
Lu, Lianghua; Pang, Zhonghe; Kong, Yanlong; Guo, Qi; Wang, Yingchun; Xu, Chenghua; Gu, Wen; Zhou, Lingling; Yu, Dandan
2018-01-01
Geothermal resources are practical and competitive clean-energy alternatives to fossil fuels, and study on the recharge sources of geothermal water supports its sustainable exploitation. In order to provide evidence on the recharge source of water and circulation dynamics of the Tangshan Geothermal System (TGS) near Nanjing (China), a comprehensive investigation was carried out using multiple chemical and isotopic tracers (δ2H, δ18O, δ34S, 87Sr/86Sr, δ13C, 14C and 3H). The results confirm that a local (rather than regional) recharge source feeds the system from the exposed Cambrian and Ordovician carbonate rocks area on the upper part of Tangshan Mountain. The reservoir temperature up to 87 °C, obtained using empirical as well as theoretical chemical geothermometers, requires a groundwater circulation depth of around 2.5 km. The temperature of the geothermal water is lowered during upwelling as a consequence of mixing with shallow cold water up to a 63% dilution. The corrected 14C age shows that the geothermal water travels at a very slow pace (millennial scale) and has a low circulation rate, allowing sufficient time for the water to become heated in the system. This study has provided key information on the genesis of TGS and the results are instructive to the effective management of the geothermal resources. Further confirmation and even prediction associated with the sustainability of the system could be achieved through continuous monitoring and modeling of the responses of the karstic geothermal reservoir to hot-water mining.
Application of environmental isotopes to groundwater investigations in Qatar
International Nuclear Information System (INIS)
Yurtsever, Y.; Payne, B.R.
1978-01-01
Environmental isotope techniques have been used to study the dynamic behaviour of the groundwater systems in Qatar. The aim was to identify the mixing processes between the shallow phreatic aquifer, the deep confined aquifers and seawater. Environmental tritium was used to estimate the average recharge of the shallow freshwater aquifer. The results of the environmental isotope study, supplemented by hydrochemical data, have clearly indicated that in the south western part of the peninsula the shallow aquifer is in direct hydraulic connection with the deeper artesian aquifers. Furthermore, the poor quality of water in that area is mainly due to substantial upward leakage of water from the deeper aquifers. In some parts of the peninsula seawater was identified as an additional source of salinity. A model was developed for estimating the turnover rate and average recharge of the phreatic aquifer from the tritium data. The results of this model provide an independent estimate of the average annual recharge. (orig.) [de
Application of environmental isotopes to groundwater investigations in Qatar
International Nuclear Information System (INIS)
Yurtsever, Y.; Payne, B.R.
1979-01-01
Environmental isotope techniques have been used to study the dynamic behaviour of the groundwater systems in Qatar. The aim was to identify the mixing processes between the shallow phreatic aquifer, the deep confined aquifers and sea-water. Environmental tritium was used to estimate the average recharge of the shallow fresh-water aquifer. The results of the environmental isotope study, supplemented by hydrochemical data, have clearly indicated that in the southwestern part of the peninsula the shallow aquifer is in direct hydraulic connection with the deeper artesian aquifers. Furthermore, the poor quality of water in that area is mainly due to substantial upward leakage of water from the deeper aquifers. In some parts of the peninsula sea-water was identified as an additional source of salinity. A model was developed for estimating the turnover rate and average recharge of the phreatic aquifer from the tritium data. The results of this model provide an independent estimate of the average annual recharge. (author)
Ground-water recharge in the arid and semiarid southwestern United States
Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.
2007-01-01
areas, and distinct modes of recharge in the Colorado Plateau and Basin and Range subregions.The chapters in this professional paper present (first) an overview of climatic and hydrogeologic framework (chapter A), followed by a regional analysis of ground-water recharge across the entire study area (chapter B). These are followed by an overview of site-specific case studies representing different subareas of the geographically diverse arid and semiarid southwestern United States (chapter C); the case studies themselves follow in chapters D–K. The regional analysis includes detailed hydrologic modeling within the framework of a high-resolution geographic-information system (GIS). Results from the regional analysis are used to explore both the distribution of ground-water recharge for mean climatic conditions as well as the influence of two climatic patterns—the El Niño-Southern Oscillation and Pacific Decadal Oscillation—that impart a high degree of variability to the hydrologic cycle. Individual case studies employ a variety of geophysical and geochemical techniques to investigate recharge processes and relate the processes to local geologic and climatic conditions. All of the case studies made use of naturally occurring tracers to quantify recharge. Thermal and geophysical techniques that were developed in the course of the studies are presented in appendices.The quantification of ground-water recharge in arid settings is inherently difficult due to the generally low amount of recharge, its spatially and temporally spotty nature, and the absence of techniques for directly measuring fluxes entering the saturated zone from the unsaturated zone. Deep water tables in arid alluvial basins correspond to thick unsaturated zones that produce up to millennial time lags between changes in hydrologic conditions at the land surface and subsequent changes in recharge to underlying ground water. Recent advances in physical, chemical, isotopic, and modeling techniques have
Environmental isotopes in the aquifers of the North Western Sahara
International Nuclear Information System (INIS)
Conrad, G.
1975-09-01
The isotopic composition of single rains at Beni-Abbes (Algeria) has been determined from 1964 to 1975. The weighed mean delta 18 O value is -3.54 %o vs. SMOW for all rains, -6.29 for rains higher than 10 mm. Only these more intense rains are believed to contribute significantly to groundwater recharge. Tritium content of precipitation varies from 900 TU in a 1964 rain, to 235 in 1967, 215 in 1968 and about 50 in 1972. The isotopic and chemical composition of water from a small salt lake nearby Beni-Abbes show variations depending on the evaporation rate and on the amount and origin of inflow. Groundwater in the Western Ground Erg contain significant amount of tritium, indicating recent recharge. The water is however submitted to evaporation as indicated by its 18 O and deuterium content. The so-called Continental Intercalaire aquifer, which extends over most of the Sahara desert, appears to be presently recharged in the outcropping areas like in Tidikelt, as shown by tritium and 14 C, and by the Western Ground Erg aquifer in the Gourara area, as shown by stable isotopes
Groundwater recharge and agricultural contamination in alluvial fan of Eastern Kofu basin, JAPAN
Nakamura, T.
2009-12-01
Agriculture has significant effects on the rate and composition of groundwater recharge. The chemical loading into groundwater have been dominated by the constituents derived directly or indirectly from agricultural practices and additives. The contamination of groundwater with nitrate is a major public health and environmental concern around the world. The inorganic constituents like, K+, Ca2+, Mg2+, SO42-, Cl- and variety of other minor elements of groundwater are often used as agricultural additives; and the natural occurrence of these elements are dominated by the agricultural sources. A recent study has reported that Kofu basin groundwater aquifer is contaminated by nitrate from agricultural areas because of the fertilizer application for the orchard (Kazama and Yoneyama, 2002; Sakamoto et al., 1997, Nakamura et al., 2007). The water-oxygen and hydrogen stable isotope (δ18O and δD) and nitrate-nitrogen stable isotope (δ15N) of groundwater, river water and precipitation samples were investigated to identify the source of groundwater and nitrate nitrogen contamination in groundwater in the Fuefukigawa and Hikawa_Kanegawa alluvial fans in Kofu basin. The plot of δD versus δ18O values of groundwater, river water and precipitation samples suggest that the groundwater is a mixture of precipitation and river water. And nitrate-nitrogen isotope values have suggested the nitrate contamination of groundwater is from agricultural area. The study revealed positive correlation between groundwater δ18O values and NO3-, Cl-, SO42-, Ca2+, Mg2+ concentration, which shows the agricultural contamination is carried by the recharge of groundwater from precipitation in alluvial fan. Whereas, NO3-, Cl-, SO42-, Ca2+, Mg2+ are diluted by the river water recharges. This study showed the quality of groundwater is resulted from the mixing of water from the different source during the groundwater recharge in the study area. References Kazama F, Yoneyama M (2002) Nitrogen generation
International Nuclear Information System (INIS)
Geldern, Robert van; Baier, Alfons; Subert, Hannah L.; Kowol, Sigrid; Balk, Laura; Barth, Johannes A.C.
2014-01-01
Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ∼20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. - Highlights: • Groundwater from deep aquifer identified as paleo-water with age over 20,000 years. • Low stable isotope values indicate recharge during Pleistocene. • Shallow aquifer mirrors stable isotope signature of average modern precipitation. • Identification of non-renewable paleo-waters enhance sustainable water management. • Strict protection measures of authorities justified by isotope geochemistry
Energy Technology Data Exchange (ETDEWEB)
Geldern, Robert van, E-mail: robert.van.geldern@fau.de [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Baier, Alfons; Subert, Hannah L. [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Kowol, Sigrid [Erlanger Stadtwerke AG, Äußere Brucker Str. 33, 91052 Erlangen (Germany); Balk, Laura; Barth, Johannes A.C. [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany)
2014-10-15
Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ∼20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. - Highlights: • Groundwater from deep aquifer identified as paleo-water with age over 20,000 years. • Low stable isotope values indicate recharge during Pleistocene. • Shallow aquifer mirrors stable isotope signature of average modern precipitation. • Identification of non-renewable paleo-waters enhance sustainable water management. • Strict protection measures of authorities justified by isotope geochemistry.
Adkins, Candice B.; Bartolino, James R.
2010-01-01
Residents of northern Ada County, Idaho, depend on groundwater for domestic and agricultural uses. The population of this area is growing rapidly and groundwater resources must be understood for future water-resource management. The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, used a suite of isotopic and environmental tracers to gain a better understanding of groundwater ages, recharge sources, and flowpaths in northern Ada County. Thirteen wells were sampled between September and October 2009 for field parameters, major anions and cations, nutrients, oxygen and hydrogen isotopes, tritium, radiocarbon, chlorofluorocarbons, and dissolved gasses. Well depths ranged from 30 to 580 feet below land surface. Wells were grouped together based on their depth and geographic location into the following four categories: shallow aquifer, intermediate/deep aquifer, Willow Creek aquifer, and Dry Creek aquifer. Major cations and anions indicated calcium-bicarbonate and sodium-bicarbonate water types in the study area. Oxygen and hydrogen isotopes carried an oxygen-18 excess signature, possibly indicating recharge from evaporated sources or water-rock interactions in the subsurface. Chlorofluorocarbons detected modern (post-1940s) recharge in every well sampled; tritium data indicated modern water (post-1951) in seven, predominantly shallow wells. Nutrient concentrations tended to be greater in wells signaling recent recharge based on groundwater age dating, thus confirming the presence of recent recharge in these wells. Corrected radiocarbon results generated estimated residence times from modern to 5,100 years before present. Residence time tended to increase with depth, as confirmed by all three age-tracers. The disagreement among residence times indicates that samples were well-mixed and that the sampled aquifers contain a mixture of young and old recharge. Due to a lack of data, no conclusions about sources of recharge could be drawn
Isotope Hydrology Investigation of Zonguldak And Province Groundwater
International Nuclear Information System (INIS)
Erduran, B.; Toerk, K.; Oektue, G.
2002-01-01
The most important coal area of Turkey is situated in Zonguldak and province. The coal series occurred during Westfalien (Carboniferous) are lower-bounded by Visean aged karstic limestones and upper-bounded by Aptian-Barremian aged karstic limestones. The isotope hydrology, which consists one of the studies dealed with karst hydrogeology, was held to determine the groundwater relations between the karstic limestones adjacent to the coal layers located in the Zonguldak coal mine areas. Environmental isotope samples were collected in the basin during 1994 - 1995 period, from the surface and groundwater. Deuterium ( 2 H), Oxygen 18 ( 18 O) and Tritium ( 3 H) analysis were carried out on the samples. Recharge elevation, water origin and transit time of the groundwater system were determined with the evaluation of the analysis results. Waters encountered in the area are of marine origined rainfall, recharging at an elevation of 400-500 meters and consisting of shallow and deep circulation systems. Groundwater that intruding the coal mine galleries, have a short flow period and are recharged from recent precipitations
Some isotope hydrological studies in Southern Africa
International Nuclear Information System (INIS)
Verhagen, B.Th.
2001-01-01
Four case studies involving the use of the environmental isotopes 14 C and 3 H, in the and to semi-arid Kalahari region of Southern Africa are described and general conclusions regarding the qualitative aspects of recharge and discharge characteristics of the systems are based on these measurements. In each of the studies, diffuse, local recharge was found to be the dominant recharge mechanism. Recharge via river beds was found to be limited at the regional scale. The balancing discharge mechanism for groundwater was found to be via evapotranspiration. Groundwater salinity and mineralisation as well as the regional hydrogeology are controlled by geological structure rather than lithologies or residence times and the absence of hypersaline groundwaters indicates that the aquifers are periodically flushed during pluvial periods, thus pointing to long-term hydroclimatic controls over the observed present-day hydrology. (author)
Jin, Ke; Rao, Wenbo; Tan, Hongbing; Song, Yinxian; Yong, Bin; Zheng, Fangwen; Chen, Tangqing; Han, Liangfeng
2018-04-01
The recharge mechanism of groundwater in the Badain Jaran Desert, North China has been a focus of research and still disputable in the past two decades. In this study, the chemical and hydrogen (H) and oxygen (O) isotopic characteristics of shallow groundwater, lake water and local precipitation in the Badain Jaran Desert and neighboring areas were investigated to reveal the relationships between various water bodies and the recharge source of shallow groundwater. Isotopic and hydrogeochemical results show that (1) shallow groundwater was associated with local precipitation in the Ayouqi and Yabulai regions, (2) lake water was mainly recharged by groundwater in the desert hinterland, (3) shallow groundwater of the desert hinterland, Yabulai Mountain and Gurinai Grassland had a common recharge source. Shallow groundwater of the desert hinterland had a mean recharge elevation of 1869 m a.s.l. on the basis of the isotope-altitude relationship and thus originated chiefly from lateral infiltration of precipitation in the Yabulai Mountain. It is further concluded that shallow groundwater flowed towards the Gurinai Grassland according to the groundwater table contour map. Along the flow pathway, the H-O isotopic variations were primarily caused by the evaporation effect but chemical variations of shallow groundwater were affected by multiple factors, e.g., evaporation effect, dilution effect of occasional heavy-precipitation and dissolution of aquifer evaporites. Our findings provide new insight into the groundwater cycle and benefit the management of the limited water resources in the arid desert area.
Chemical and isotopic properties of groundwater along the coastal plain of the aqaba gulf, (EG)
International Nuclear Information System (INIS)
Awad, M.A.A
1999-01-01
Isotopic and hydrochemical studies were undertaken along the coastal plain of aqaba gulf in taba, dahab and sharm El-Sheikh to ascertain the role of precipitation (via floods), local water and sea water intrusion as replenishment sources for available groundwater resources in these areas. From the isotopic point of view, it can be concluded that groundwater in nuweiba wells appears to have been recharged from continental and mediterranean participation, while in dahab wells and sharm El-Sheikh Nubian well, recent precipitation via monsoonal air masses which comes from indian ocean plays a considerable role in recharging of these wells. In Taba wells, seepage of partly evaporated flood water represents the main source of their recharge. The fractured nature of the studied area has an effect on the occurrence of groundwater. The variation in chemical water type is due to leaching of terrestrial salts and impact of marine faces (i.e. evaporites and sea spray). Sea water intrusion via over pumping and/ or during tide and ebb duration shows an affect-to some extent-on the chemical composition of some localized wells. Construction of meteorological stations in scattered sites all over sinai is necessary to collect rainwater and floods samples periodically, to study the modification of the isotopic composition of rainwater by processes which occur before groundwater recharge using environmental isotopes
International Nuclear Information System (INIS)
Aly, A.I.M.; Nada, A.; Awad, M.; Hamza, M.; Salem, W.M.
1993-01-01
Oxygen-18 ( 18 O) and deuterium isotopes were used to estimate the evaporation from the Aswan High Dam Lake and to investigate the inter-relation between the lake water and adjacent groundwater. According to stable isotopic analysis of samples taken in 1988 and 1989, the lake can be divided into two sections. In the first section extending between Abu Simbel and a point between El-Alaki and Krosko, a remarkable vertical gradient of 18 O and deuterium isotopic composition was observed. The second northern sector extending to the High Dam is characterised by a lower vertical isotopic gradient. In this sector in general, higher values of 18 O and deuterium contents were found at the top and lower values at the bottom. Also a strong horizontal increase of the heavy isotope content was observed. Thus, in the northern section evaporation is of dominating influence on the isotopic composition of the lake water. With the help of an evaporation pan experiment it was possible to calibrate the evaporative isotope enrichment in the lake and to facilitate a preliminary estimate of evaporative losses of lake water. The evaporation from the lake was estimated to be about 19% of the input water flow rate. The groundwater around the lake was investigated and samples from production wells and piezometers were subjected to isotopic analysis. The results indicate that recent recharge to the groundwater aquifer is limited to wells near to the lake and up to a maximum distance of about 10 km. The contribution of recent Nile water to the groundwater in these wells was estimated to range between 23 and 70%. Beyond this distance, palaeowater was observed with highly depleted deuterium and 18 O contents, which was also confirmed by 14c dating. The age of palaeo groundwater in this area can reach values of more than 26,000 years. Recommendations are given for efficient water management of the lake water. (Author)
Katz, Brian G.; Catches, John S.; Bullen, Thomas D.; Michel, Robert L.
1998-11-01
The Little River, an ephemeral stream that drains a watershed of approximately 88 km 2 in northern Florida, disappears into a series of sinkholes along the Cody Scarp and flows directly into the carbonate Upper Floridan aquifer, the source of water supply in northern Florida. The changes in the geochemistry of ground water caused by a major recharge pulse from the sinking stream were investigated using chemical and isotopic tracers and mass-balance modeling techniques. Nine monitoring wells were installed open to the uppermost part of the aquifer in areas near the sinks where numerous subterranean karst solution features were identified using ground penetrating radar. During high-flow conditions in the Little River, the chemistry of water in some of the monitoring wells changed, reflecting the mixing of river water with ground water. Rapid recharge of river water into some parts of the aquifer during high-flow conditions was indicated by enriched values of delta 18O and delta deuterium (-1.67 to -3.17 per mil and -9.2 to -15.6 per mil, respectively), elevated concentrations of tannic acid, higher (more radiogenic) 87Sr/ 86Sr ratios, and lower concentrations of 222Rn, silica, and alkalinity compared to low-flow conditions. The proportion of river water that mixed with ground water ranged from 0.10 to 0.67 based on binary mixing models using the tracers 18O, deuterium, tannic acid, silica, 222Rn, and 87Sr/ 86Sr. On the basis of mass-balance modeling during steady-state flow conditions, the dominant processes controlling carbon cycling in ground water are the dissolution of calcite and dolomite in aquifer material, and aerobic degradation of organic matter.
International Nuclear Information System (INIS)
Djoret, D.; Travi, Y.
2001-01-01
Stable isotopes and major chemical elements have been used to investigate present or ancient groundwater renewal in the multilayered aquifer of the Chari-Baguirmi plain, South of Lake Chad. On the Western side, recharge mainly occurs from the Chari River during the flood period. Within the Ndjamena area, the rise of the piezometric level in the contaminated subsurface zone provokes an increase in nitrate concentrations. Rainfall recharge is mainly located close to the outcropping basement, i.e. on the Eastern side of the area and does not occurs in the central part of the plain where groundwater also presents a stronger evaporative signature. This supports the hypothesis attributing a major role to evaporation processes in the formation of piezometric depressions in the Sahel zone. There is no evidence of present day or ancient water recharge from Lake Chad. (author)
The isotope hydrology of the northern well field, Jwaneng diamond mine, Botswana
International Nuclear Information System (INIS)
Verhagen, B.Th.; Brook, M.C.
1989-01-01
The northern well field supplies the Jwaneng diamond mine with 4.8x10 6 m 3 /a of good quality ground water. Model predictions, based on hydraulic parameters obtained during initial development, were found to have overestimated well field drawdown and have been twice updated in the past seven years. Since 1983, various surveys of environmental isotope levels in the well field ground water were conducted. Over the period of observation, there has been very little change in the initial conclusion that part of the well field contains suprisingly recent ground water. Active recharge, which was suspected from the chemical composition of the ground water, was therefore confirmed, as well as the fact that the ground water body as a whole is dynamic. The isotopic data are discussed in terms of regional information from the surrounding Karoo aquifers. It is shown that earlier theories of remote recharge to the well field are untenable. More recent data on first strike and other water samples obtained during exploring drilling are incorporated. Estimates based on the hydrological picture presented by the isotope data, indicate economically significant local rain recharge. A simple analytical model of well field behaviour shows that this calculated recharge rate brings the modelled drawdowns into the range of actually observed values. 10 refs., 7 figs
Isotope hydrology and its impact in the developing world
International Nuclear Information System (INIS)
Verhagen, B.Th.
2003-01-01
Ground water has increasingly taken its place in the provision of safe, potable supply in the developing world. Large investments have been made in infrastructural development for rural ground water supply schemes, but far too little attention has been given to assess the sustainability of these supplies. Overexploitation of aquifers, evident in failing boreholes and deteriorating water quality, has become a world-wide concern. Developments in physics half a century ago established the basis of isotope hydrology. Radioactive isotopes give information on ground water dynamics and recharge rates whilst non-radioactive - or stable - isotopes indicate origins of ground water and delineate ground water bodies. Environmental isotope hydrology is increasingly seen as a powerful discipline in assessing ground water systems. This is particularly important in developing environments, where historical data is rarely available. Brief examples are presented of isotope applications to collaborative ground water studies conducted at the University of the Witwatersrand. Recharge estimates based on isotope 'snapshot' data conform well with results from subsequent long-term water level observations in the Kalahari of Botswana. The importance is demonstrated of irrigation return flow and pollution hazard to the Lomagundi dolomite of Zimbabwe. Isotopes suggest the source of high nitrate concentrations to an important ground water supply in Tanzania. Mechanisms of the release of arsenic into millions of tube wells in Bangladesh are put into perspective. Isotope hydrology as appropriate technology is highlighted in terms of its cost-effectiveness and the investigative empowerment of local investigators. (author)
Report on the environmental isotopic investigations in Kedah and Perlis Area, Malaysia (Part 1)
International Nuclear Information System (INIS)
Daud bin Mohamad.
1982-11-01
A preliminary study of the isotope hydrology of the Kedah and Perlis area was undertaken under the RCA programme. This project is an attempt at elucidating the mechanism of recharge, origin, area of recharge and dating of groundwater system in the area. The results show that all groundwater samples in the area vary within a narrow range for 18 0 (-7.58 to -5.06%) while 2 H ranges from -50.3 to -35.1%. The mean isotopic composition of precipitation collected at Alor Star meteorological station fall within the range of variation of the Kedah/Perlis groundwaters. In the southern part of the study site, the isotopic results indicate the occurence of two types of water: firstly, the recharge is from the highlands where more negative 18 0 values and low tritium were observed and the second type is of local recharge where high tritium and less negative 18 0 values were observed. On the other hand, in the northern part of the basin the interpretation of stable isotopic results is quite difficult to be made at this stage. There was no correlation at all between tritium and 18 0 whatsoever. Results of the tritium assay show that some of the groundwater samples are pre-nuclear in age as indicated by low tritium content. Consequently, a Carbon-14 investigation was carried out from a few selected sites and their ages were found to be in the range of about 3000 to 5000 years. (author)
Environmental isotopic study of the Korama aquifers, south of Zinder (Niger)
International Nuclear Information System (INIS)
Zakara, Z.; Karbo, A.; Aranyossy, J.F.
1993-01-01
A first environmental isotope study has been carried out on the ''Korama'' aquifers located in the southern part of the city of Zinder (Niger). Preliminary interpretation confirms that most of the aquifers are presently recharged by direct infiltration of rainwater. Structural fractures seem to play an important role in the water circulation allowing vertical drainage of oldest water coming from deeper aquifers and facilitating the recharge by surface water in the prheatic zone. It does not appear any difference between the so-called ''superficial Korama'' and the ''Deep Korama'' aquifers on the basis of the isotopic compositions. (author). 11 refs, 7 figs, 2 tabs
Isotope hydrology study of Kato Nevrokopi of Dramas
International Nuclear Information System (INIS)
Leontiadis, I.L.; Payne, B.R.; Letsios, A.; Papagianni, N.; Kakarelis, D.; Chadjiagorakis, D.
1984-01-01
The isotopic composition of the water was used in order to define the mechanism of recharge of the high plateau of Kato Nevrokopi of Dramas. The results of this study indicate that there are two main sources of recharge to groundwater. One is infiltration of water from the network of irrigation canals which carry water from the Vathitopos stream. The other source of recharge originates in the mountains to the east of the plain. Infiltration from the Nevrokopi stream does occur, but is believed to be minor in this part of the plain. Recharge by infiltration of local precipitation is considered to be minor in comparison with the two main sources of recharge. An underground barrier prevents draining of the groundwater through the sinkhole, resulting in a very big reservoir under the whole central and southern parts of the high plateau. The exploitation of the groundwater of this reservoir very probably offers a low-cost solution to satisfy all needs of the area for irrigation water. (author)
International Nuclear Information System (INIS)
Kamdee, K.; Laoharojanaphand, S.; Noipow, N.; Jaruratanab, A.; Detoup, D.; Chantarachota, W.
2011-06-01
Full text: A new analysis method of stable isotope was developed by using the absorption characteristic of pulsed laser beam concept for trace gas analysis (O'Keefe, 1989). The method provides high performance and analysis capacity but contribute less applicative compared to the traditional IRMS methods by using only pure liquids phase of water. The methods are using with environmental isotopes techniques to improve groundwater management of the Chiang Mai Basin, the biggest Cenozoic basin in the northern part of Thailand. Unconsolidated and consolidated sediments form three main aquifers, the Chao Phraya, Chiang Rai and Chiang Mai Aquifers, show clearly unconfined to confined characteristic. From chemical composition of the groundwater, most of groundwater samples are of calcium-magnesium bicarbonate and sodium-potassium bicarbonate type and few of them show the risk of fluorine content for drinking purpose. Radioactive Carbon results showed the ages of groundwater vary from 2,300 ±240 to +30,000 years. The tritium results showed low tritium content, less than 1.0 Tritium Unit (T.U.) in all groundwater samples, was compared to the surface water that arranged from 2.1-2.6 T.U. The stable isotope result of the liquid water isotope analyzer (Los Gatos Research: DLT-100) indicated the main recharge resources of groundwater in the basin was from the local rain water in terrace area and from both sides of the basin at different altitudes. Surface water from rivers and dams have no contribution to the origin of groundwater in the basin. The radioactive and stable isotope data of ground water from different aquifers did not show clear separation and was similar to the previous study of the basin in 1993 (Buapheng et al., 1993). Thus, the recent data accrue to be convinced that there was some mixing of groundwater within three aquifers and rather slow replenishment. The conceptual modeling of groundwater system in Chiang Mai Basin can be revised. The Upper part of Chiang
Energy Technology Data Exchange (ETDEWEB)
Wang, Shiqin [Faculty of Horticulture, Chiba University, Matsudo-City 271-8510 (Japan); Tang, Changyuan, E-mail: cytang@faculty.chiba-u.jp [Faculty of Horticulture, Chiba University, Matsudo-City 271-8510 (Japan); Song, Xianfang [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Wang, Qinxue [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); Zhang, Yinghua [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Yuan, Ruiqiang [College of Environment and Resources, Shanxi University (China)
2014-06-01
Sewage leakage has become an important source of groundwater recharge in urban areas. Large linear wastewater ponds that lack anti-seepage measures can act as river channels that cause the deterioration of groundwater quality. This study investigated the groundwater recharge by leakage of the Tanghe Wastewater Reservoir, which is the largest industrial wastewater channel on the North China Plain. Additionally, water quality evolution was investigated using a combination of multivariate statistical methods, multi-tracers and geochemical methods. Stable isotopes of hydrogen and oxygen indicated high levels of wastewater evaporation. Based on the assumption that the wastewater was under an open system and fully mixed, an evaporation model was established to estimate the evaporation of the wastewater based on isotope enrichments of the Rayleigh distillation theory using the average isotope values for dry and rainy seasons. Using an average evaporation loss of 26.5% for the input wastewater, the estimated recharge fraction of wastewater leakage and irrigation was 73.5% of the total input of wastewater. The lateral regional groundwater inflow was considered to be another recharge source. Combing the two end-members mix model and cluster analysis revealed that the mixture percentage of the wastewater decreased from the Highly Affected Zone (76%) to the Transition Zone (5%). Ion exchange and redox reaction were the dominant geochemical processes when wastewater entered the aquifer. Carbonate precipitation was also a major process affecting evolution of groundwater quality along groundwater flow paths. - Highlights: • An unlined wastewater reservoir caused the deterioration of groundwater quality. • An evaporation fraction was estimated by Rayleigh distillation theory of isotopes. • 73.5% of wastewater recharge to groundwater by leakage and irrigation infiltration. • The region influenced by wastewater was divided into four subzones. • Mixing, ion exchange, and
Anderson, Katherine; Nelson, Stephen; Mayo, Alan; Tingey, David
2006-05-01
Springs in the Furnace Creek area (Texas, Travertine, and Nevares Springs) of Death Valley National Park exhibit high discharge rates and depleted δ18O VSMOW (˜-13‰) and δD VSMOW (˜-102‰) values. Isotopic depletion of this magnitude and large spring fluxes (˜10,000 L/min) suggests that modern local recharge in the arid Furnace Creek drainage cannot be responsible for spring fluxes. An alternate explanation, interbasin flow, is difficult to envisage due to the stratigraphic and structural relationships of bedrock in intervening ranges, although it is the most common conceptual model for Furnace Creek spring flows. High-flux springs at Furnace Creek nonetheless respond modestly to modern climate in terms of discharge rate and isotopic composition. Hydrographs show a climate response and variations in time-series stable isotope data of widely spaced springs track one another. Small, but measurable quantities of tritium (water for these springs may be, there appears to be a subtle, but recent climatic influence. Estimates of flow at nearby mountain springs produce discharge rates per square kilometer of catchment that, by analogy, could support from 20 to 300% of the flow at large Death Valley springs under the current climate. Yet, 14C model ages suggest valley-bottom springs at Furnace Creek (5500-14,500 yr) contain a large component of older water, suggesting that much of the water was recharged during a pluvial period (Younger Dryas?) when net infiltration would have been much higher and isotopically depleted. 14C model ages are also of similar age, or younger, than many 'up gradient' waters, rather than being older as would be expected for interbasin flow. Chemical evolution models of solutes are consistent with both local recharge and interbasin transfer from Ash Meadows. However, when considered with isotopic constraints, interbasin flow becomes obviously untenable. Estimates of the thickness of alluvium and semi-consolidated Tertiary units in the
International Nuclear Information System (INIS)
1999-05-01
The papers presented at the symposium dealt with environmental isotope measurements and tracer techniques in studies on sedimentation, groundwater recharge, dynamics and pollution; discussed isotope data interpretation; and presented recent advances in analytical techniques for isotope hydrology. This document contains 139 extended synopses; each of them was indexed individually
Isotopes in hydrology of ground water
International Nuclear Information System (INIS)
Rodriguez, N.; C, O.
1996-01-01
Fundamental concepts on Radioactivity, Isotopes, Radioisotopes, Law of Nuclear Decay (Middle Life concept), Radioactivity units, Types of radiation, Absorption and dispersion of both Alfa and Beta particles and both gamma and X-rays attenuation are presented. A description on Environmental Isotopes (those that are presented in natural form in the environment and those that can't be controlled by the humans), both stables and unstable (radioisotopes) isotopes is made. Isotope hydrology applications in surface water investigations as: Stream flow measurements and Atmosphere - surface waters interrelationship is described. With relation to the groundwater investigations, different applications of the isotope hydrology, its theoretical base and its methodology are presented to each one of the substrates as: Unsaturated zone (soil cape), Saturated zone (aquifer cape), Surface waters - ground waters interrelationship (infiltration and recharge) and to hydrologic balance
Ganot, Yonatan; Russak, Amos; Siebner, Hagar; Bernstein, Anat; Katz, Yoram; Guttman, Jospeh; Kurtzman, Daniel
2017-04-01
In the last three years we monitor Managed Aquifer Recharge (MAR) of post-treated desalinated seawater (PTDES) in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. The PTDES are stabilized with CaCO3 during post-treatment in the desalination plant and their chemical composition differs from those of any other water recharged to the aquifer and of the natural groundwater. We use suction cups in the unsaturated zone, shallow observation wells within the pond and production wells that encircles the MAR Menashe site, to study the geochemical processes during MAR with PTDES. Ion-enrichment (remineralization) of the recharged water was observed in both unsaturated zone and shallow observation wells samples. Enrichment occurs mainly in the first few meters below the pond surface by ion-exchange processes. Mg2+ enrichment is most prominent due to its deficiency in the PTDES. It is explained by ion-exchange with Ca2+, as the PTDES (enriched with Ca2+) infiltrates through a calcareous-sandstone aquifer with various amount of adsorbed Mg2+ (3-27 meq/kg). Hence, the higher concentration of Ca+2 in the PTDES together with its higher affinity to the sediments promotes the release of Mg2+ ions to the recharged water. Water isotopes analysis of the production wells were used to estimate residence time and mixing with local groundwater. At the end of 2016, it was found that the percentage of PTDES in adjacent down-gradient production wells was around 10%, while more distant or up-gradient wells show no mixing with PTDES. The distinct isotope contrast between the recharged desalinated seawater (δ2H=+11.2±0.2‰) and the local groundwater (δ2H ranged from -22.7 to -16.7‰) is a promising tool to evaluate future mixing processes at the Menshae MAR site. Using the Menashe MAR system for remineralization could be beneficial as a primary or complementary post-treatment technique. However, the sustainability of this process is
International Nuclear Information System (INIS)
Rockhold, M.L.; Fayer, M.J.; Kincaid, C.T.; Gee, G.W.
1995-03-01
In 1994, the Pacific Northwest Laboratory (PNL) initiated the Recharge Task, under the PNL Vitrification Technology Development (PVTD) project, to assist Westinghouse Hanford Company (WHC) in designing and assessing the performance of a low-level waste (LLW) disposal facility for the US Department of Energy (DOE). The Recharge Task was established to address the issue of ground water recharge in and around the LLW facility and throughout the Hanford Site as it affects the unconfined aquifer under the facility. The objectives of this report are to summarize the current knowledge of natural ground water recharge at the Hanford Site and to outline the work that must be completed in order to provide defensible estimates of recharge for use in the performance assessment of this LLW disposal facility. Recharge studies at the Hanford Site indicate that recharge rates are highly variable, ranging from nearly zero to greater than 100 mm/yr depending on precipitation, vegetative cover, and soil types. Coarse-textured soils without plants yielded the greatest recharge. Finer-textured soils, with or without plants, yielded the least. Lysimeters provided accurate, short-term measurements of recharge as well as water-balance data for the soil-atmosphere interface and root zone. Tracers provided estimates of longer-term average recharge rates in undisturbed settings. Numerical models demonstrated the sensitivity of recharge rates to different processes and forecast recharge rates for different conditions. All of these tools (lysimetry, tracers, and numerical models) are considered vital to the development of defensible estimates of natural ground water recharge rates for the performance assessment of a LLW disposal facility at the Hanford Site
Borehole environmental tracers for evaluating net infiltration and recharge through desert bedrock
Heilweil, V.M.; Solomon, D.K.; Gardner, P.M.
2006-01-01
Permeable bedrock aquifers in arid regions are being increasingly developed as water supplies, yet little is generally known about recharge processes and spatial and temporal variability. Environmental tracers from boreholes were used in this study to investigate net infiltration and recharge to the fractured Navajo Sandstone aquifer. Vadose zone tracer profiles at the Sand Hollow study site in southwestern Utah look similar to those of desert soils at other sites, indicating the predominance of matrix flow. However, recharge rates are generally higher in the Navajo Sandstone than in unconsolidated soils in similar climates because the sandstone matrix allows water movement but not root penetration. Water enters the vadose zone either as direct infiltration of precipitation through exposed sandstone and sandy soils or as focused infiltration of runoff. Net infiltration and recharge exhibit extreme spatial variability. High-recharge borehole sites generally have large amounts of vadose zone tritium, low chloride concentrations, and small vadose zone oxygen-18 evaporative shifts. Annual net-infiltration and recharge rates at different locations range from about 1 to 60 mm as determined using vadose zone tritium, 0 to 15 mm using vadose zone chloride, and 3 to 60 mm using groundwater chloride. Environmental tracers indicate a cyclical net-infiltration and recharge pattern, with higher rates earlier in the Holocene and lower rates during the late Holocene, and a return to higher rates during recent decades associated with anomalously high precipitation during the latter part of the 20th century. The slightly enriched stable isotopic composition of modern groundwater indicates this recent increase in precipitation may be caused by a stronger summer monsoon or winter southern Pacific El Nin??o storm track. ?? Soil Science Society of America.
International Nuclear Information System (INIS)
Carreira, Paula M.; Nunes, Dina; Marques, Jose M.; Monteiro Santos, Fernando A.; Goncalves, Rui; Pina, Antonio; Mota Gomes, Antonio
2013-01-01
Stable isotopes (δ 18 O, δ 2 H) and tritium ( 3 H), together with geochemistry and geophysical data, were used for evaluating groundwater recharge sources, flow paths, and residence times in a watershed on Santiago Island, Cape Verde, West Africa. Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. Low tritium concentrations at seven sampling sites indicate groundwater residence times greater than 50 years. Higher tritium values at other locations suggest more recent recharge. Young ages indicate local recharge and potential groundwater vulnerability to surface contamination and/or salt-water intrusion. Geochemical results indicate that water-rock interaction mechanisms are the major processes responsible for the groundwater quality (mainly calcium-bicarbonate type), reflecting the lithological composition of subsurface soil. (authors)
Energy Technology Data Exchange (ETDEWEB)
Carreira, Paula M.; Nunes, Dina [Quimica Analitica e Ambiental, IST/ITN, Universidade Tecnica de Lisboa, Estrada Nacional no. 10, 2686-953 Sacavem (Portugal); Marques, Jose M. [Centro de Petrologia e Geoquimica. Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Monteiro Santos, Fernando A. [Universidade de Lisboa-IDL, 1749-016 Lisboa (Portugal); Goncalves, Rui [Inst. Politecnico de Tomar, Quinta do Contador, Estrada da Serra, 2300 Tomar (Portugal); Pina, Antonio; Mota Gomes, Antonio [Instituto Superior de Educacao, Praia, Santiago (Cape Verde)
2013-07-01
Stable isotopes (δ{sup 18}O, δ{sup 2}H) and tritium ({sup 3}H), together with geochemistry and geophysical data, were used for evaluating groundwater recharge sources, flow paths, and residence times in a watershed on Santiago Island, Cape Verde, West Africa. Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. Low tritium concentrations at seven sampling sites indicate groundwater residence times greater than 50 years. Higher tritium values at other locations suggest more recent recharge. Young ages indicate local recharge and potential groundwater vulnerability to surface contamination and/or salt-water intrusion. Geochemical results indicate that water-rock interaction mechanisms are the major processes responsible for the groundwater quality (mainly calcium-bicarbonate type), reflecting the lithological composition of subsurface soil. (authors)
Isotope study in geothermal fields in Java Island
International Nuclear Information System (INIS)
Wandowo, Z.A.
1995-01-01
Study in two geothermal fields, Dieng and Kamojang, in Java island by utilizing isotope technique has been carried out. Isotopic data of wells, springs and other geothermal manifestations providing informations on the recharge area of precipitation contributed to geothermal resources, flow paths and origin of geothermal fluids. The data of oxygen shift has also provided information on the characteristic the fields. (author). 8 refs, 5 figs, 3 tabs
He, Xin; Song, Xiyun; Frey, Eric C
2008-11-01
The diagnosis of cardiac disease using dual-isotope myocardial perfusion SPECT (MPS) is based on the defect status in both stress and rest images, and can be modeled as a three-class task of classifying patients as having no, reversible, or fixed perfusion defects. Simultaneous acquisition protocols for dual-isotope MPS imaging have gained much interest due to their advantages including perfect registration of the (201)Tl and (99m)Tc images in space and time, increased patient comfort, and higher clinical throughput. As a result of simultaneous acquisition, however, crosstalk contamination, where photons emitted by one isotope contribute to the image of the other isotope, degrades image quality. Minimizing the crosstalk is important in obtaining the best possible image quality. One way to minimize the crosstalk is to optimize the injected activity of the two isotopes by considering the three-class nature of the diagnostic problem. To effectively do so, we have previously developed a three-class receiver operating characteristic (ROC) analysis methodology that extends and unifies the decision theoretic, linear discriminant analysis, and psychophysical foundations of binary ROC analysis in a three-class paradigm. In this work, we applied the proposed three-class ROC methodology to the assessment of the image quality of simultaneous dual-isotope MPS imaging techniques and the determination of the optimal injected activity combination. In addition to this application, the rapid development of diagnostic imaging techniques has produced an increasing number of clinical diagnostic tasks that involve not only disease detection, but also disease characterization and are thus multiclass tasks. This paper provides a practical example of the application of the proposed three-class ROC analysis methodology to medical problems.
He, H. Y.; Shi, X. F.; Zhu, W.; Wang, C. Q.; Ma, H. W.; Zhang, W. J.
2017-11-01
The city conducted groundwater artificial recharge test which was taken a typical site as an example, and the purpose is to prevent and control land subsidence, increase the amount of groundwater resources. To protect groundwater environmental quality and safety, the city chose tap water as recharge water, however, the high cost makes it not conducive to the optimal allocation of water resources and not suitable to popularize widely. To solve this, the city selects two major surface water of River A and B as the proposed recharge water, to explore its feasibility. According to a comprehensive analysis of the cost of recharge, the distance of the water transport, the quality of recharge water and others. Entropy weight Fuzzy Comprehensive Evaluation Method is used to prefer tap water and water of River A and B. Evaluation results show that water of River B is the optimal recharge water, if used; recharge cost will be from 0.4724/m3 to 0.3696/m3. Using Entropy weight Fuzzy Comprehensive Evaluation Method to confirm water of River B as optimal water is scientific and reasonable. The optimal water management decisions can provide technical support for the city to carry out overall groundwater artificial recharge engineering in deep aquifer.
Environmental isotope studies on groundwater problems in the Thar Desert, India
International Nuclear Information System (INIS)
Nair, A.R.; Navada, S.V.; Rao, S.M.
1997-01-01
One of the groundwater problems encountered in arid areas like the Thar Desert in Rajasthan is to know whether the shallow groundwater is being actively recharged. Environmental isotopes particularly tritium are very useful in providing evidence of recent recharge. In the Barmer area, the shallow groundwaters have tritium levels generally in the range 3-6 TU showing modern recharge. Most of the recharge possibly occurs by direct infiltration of precipitation. Indirect recharge through wadis (river channels) could sometimes be an important mechanism of groundwater recharge. Environmental isotope study in Jalore area showed that the shallow groundwaters near the Sukri river course had δ 2 H and δ 18 O are depleted compared to present day precipitation but not as depleted as the present day Himalayan rivers. Carbon-24 values of some of these groundwaters are in the range of 54-58 pMC showing that they possibly represent old river with headwater connection outside the desert. In the Thar, the deep groundwaters which sometimes form the bulk of water supply are generally paleowaters as sown by environmental δ 2 H, δ 18 O, 3 H and 14 C. For example in the Barmer area, deep groundwaters (depth > 150m) have depleted δ 2 H and δ 18 O compared to the shallow groundwaters and present day precipitation. They have negligible 3 H and 14 C model ages ranging from 4000 to 9500 BP. Hence the isotope data of the deep groundwaters indicate they are paleowaters recharged during humid periods in the Holocene. Over-exploitation of deep groundwaters could lead to mixing of shallow and deep groundwaters or influx of waters from adjoining aquifers. In the Bikaner area similar δ 2 H and δ 18 O of the shallow and deep wells and young waters encountered in some of the deep wells indicated mixing between the two aquifers due to heavy exploitation of groundwaters in the area. In a limestone belt of Jodhpur-Nagaur district heavy exploitation of groundwaters is taking place in the southern
Use of natural isotopes and groundwater quality for improved ...
African Journals Online (AJOL)
2006-07-21
Jul 21, 2006 ... Use of natural isotopes and groundwater quality for improved recharge ..... the environmental impact and the effectiveness of clean-up measures is ..... VEGTER JR and FOSTER MBJ (1990) The Hydrogeology of Dolomitic.
Energy Technology Data Exchange (ETDEWEB)
NONE
1999-05-01
The papers presented at the symposium dealt with environmental isotope measurements and tracer techniques in studies on sedimentation, groundwater recharge, dynamics and pollution; discussed isotope data interpretation; and presented recent advances in analytical techniques for isotope hydrology. This document contains 139 extended synopses; each of them was indexed individually Refs, figs, tabs
International Nuclear Information System (INIS)
Gonfiantini, R.; Sauzay, G.; Payne, B.R.; Conrad, G.; Fontes, J.Ch.
1974-01-01
The Northern Sahara contains several aquifers, the largest of which is that of the Continental Intercalaire formations. In its eastern part the aquifer is confined and presents a very homogeneous isotopic composition. The 14 C activity is low or zero except in the outcrop zones of the north (Saharan Atlas), the east (Dahar) and the south (Tinrhert), all of which are recharge zones. In these areas the isotopic composition does not differ appreciably from that of the old water in the confined part of the aquifer. In the western part, where the reservoir outcrops widely, the 14 C activities show the extent of the local recharge. The heavy isotope content indicates the overflow of the surface aquifer of the western Grand Erg into the Continental Intercalaire over the whole Gourara front. The mixtures thus formed pass under the Tademait and drain towards the Touat. In the resurgence zone of the Gulf of G abes in Tunisia the heavy-isotope content confirms the recharging of the aquifer of the Complex terminal by drainage of water from the Continental Intercalaire through the El-Hamma fault system. The water then runs eastwards, mixing with local contributions. The marine Miocene confined aquifer of Zarzis-Djerba in the Gulf of Gabes receives no contribution from the Continental Intercalaire. The water in the aquifer of the western Grand Erg indicates an evaporation mechanism, probably peculiar to the dune systems, which gives rise to heavy-isotope enrichment compared with the recharge of other types of formations. (author) [fr
Directory of Open Access Journals (Sweden)
Sonja Cerar
2013-01-01
Full Text Available Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A total of 138 groundwater samples were collected at 69 sampling locations from both aquifers. Major carbonate ions and the stable isotope of oxygen were used to identify differences in the recharging areas of aquifers. Four groups of groundwater were identified: (1 Ljubljansko polje aquifer, with higher Ca2+ values, as limestone predominates in its recharge area, (2 northern part of Ljubljansko Barje aquifer, with prevailing dolomite in its recharge area, (3 central part of Ljubljansko Barje aquifer, which lies below surface cover of impermeable clay and is poor in carbonate, and (4 Brest and Iški vršaj aquifer in the southern part of Ljubljansko Barje with higher Mg2+ in groundwater and dolomite prevailing in its recharge area. The radioactive isotope tritium was also used to estimate the age of groundwater. Sampled groundwater is recent with tritium activity between 4 and 8 TU and residence time of up to 10 years.
Recharge Data Package for Hanford Single-Shell Tank Waste Management Areas
Energy Technology Data Exchange (ETDEWEB)
Fayer, Michael J.; Keller, Jason M.
2007-09-24
Pacific Northwest National Laboratory (PNNL) assists CH2M HILL Hanford Group, Inc., in its preparation of the Resource Conservation and Recovery Act (RCRA) Facility Investigation report. One of the PNNL tasks is to use existing information to estimate recharge rates for past and current conditions as well as future scenarios involving cleanup and closure of tank farms. The existing information includes recharge-relevant data collected during activities associated with a host of projects, including those of RCRA, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the CH2M HILL Tank Farm Vadose Zone Project, and the PNNL Remediation and Closure Science Project. As new information is published, the report contents can be updated. The objective of this data package was to use published data to provide recharge estimates for the scenarios being considered in the RCRA Facility Investigation. Recharge rates were estimated for areas that remain natural and undisturbed, areas where the vegetation has been disturbed, areas where both the vegetation and the soil have been disturbed, and areas that are engineered (e.g., surface barrier). The recharge estimates supplement the estimates provided by PNNL researchers in 2006 for the Hanford Site using additional field measurements and model analysis using weather data through 2006.
How much of stream and groundwater comes from snow? A stable isotope perspective in the Swiss Alps
Beria, H.; Schaefli, B.; Ceperley, N. C.; Michelon, A.; Larsen, J.
2017-12-01
Precipitation which once fell as snow is predicted to fall more often as liquid rain now that climate is, and continues, warming. Within snow dominated areas, preferential winter groundwater recharge has been observed, however a shorter winter season and smaller snow fraction results in earlier snowmelt and thinner snowpacks. This has the potential to change the supply of snow water sources to both streams and groundwater, which has important implications for flow regimes and water resources. Stable isotopes of water (2H and 18O) allow us to discriminate rain vs snow signatures within water flowing in the stream or the subsurface. Using one year of isotope data collected in a Swiss Alpine catchment (Vallon de Nant, Vaud), we developed novel forward Bayesian mixing models, based on statistical and empirical likelihoods, to quantify source contributions and uncertainty estimates. To account for the spatial heterogeneity in precipitation isotopes, we parameterized the model accounting for elevation effects on isotopes, calculated using the network of GNIP stations in Switzerland. Instead of sampling meltwater, we sampled snowpack throughout the season and across a steep elevation gradient (1241m to 2455m) to infer the snowmelt transformation factor. Due to continuous mixing within the snowpack, the snowmelt water shows much lower variability in its isotopic range which is reflected in the snow transformation factor. Snowmelt yield to groundwater recharge per unit amount of precipitation was found to be greater than rainfall in Vallon de Nant, suggesting strongly preferential winter recharge. Seasonal dynamics of stream responses to rain-on-snow events, fog deposition, snowmelt and summer rain were also explored. Innovative monitoring and sampling with tools such as stable isotopes and forward Bayesian mixing models are key to improved comprehension of global recharge mechanisms.
Energy Technology Data Exchange (ETDEWEB)
Pang, Z.; Huang, T.; Kong, Y. [Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing (China)
2013-07-15
Since 2000, more than 2 billion m{sup 3} of water has been diverted from the Peacock River to the neighbouring Lower Tarim River in NW China via a 900 km canal for ecosystem rescue by cross-catchment water diversion. Isotope techniques have been used in the riparian groundwater- river interactions along the 350 km long river channel through sampling of monitoring wells and river stream as well as soil profiles. Stable isotopes ({delta}{sup 2}H, {delta} {sup 18}O) show that groundwater is enriched in heavy isotopes, attributed to evaporation during recharge. Tritium data show that the extent of modern recharge is limited to 600-1500 m from the riverbank in the middle reaches and 200-600 m in the lower reaches. The salinity of groundwater is affected by river recharge, residence time and evapotranspiration. The zone of appropriate water table for arid plants is confined to a narrow scope. The assessment calls for a more favourable water allocation and management scheme catchment wide. (author)
International Nuclear Information System (INIS)
Chilton, P.J.; Stuart, M.E.; Darling, W.G.
1998-01-01
Agricultural irrigation with wastewater is widely practised in Mexico, often in areas where the underlying aquifers are used for potable water supply. Studies in two areas of the country have examined the fate and behaviour of contaminants from untreated wastewater. The use of δ 18 O and δ 2 H isotopes was integrated with hydrogeological techniques such as core drilling, geophysics, major ion and trace element analysis of water samples, soil sampling and simple modelling. In both study areas, the isotope data helped to confirm the hydrochemical results. Conventional plots of δ 2 H and δ 18 O provide indications of altitude differences and evaporation processes in looking at sources of recharge. Plotting δ 18 O against chloride provides a convenient way of distinguishing groundwater types. In Leon, isotopic data confirmed that recharge to the deep volcanic-rock aquifer underlying the area of wastewater irrigation came partly from the surrounding mountains where this formation outcrops. In the Mezquital Valley, recharge to groundwaters beneath the valley floor originates from infiltration of wastewater. Comparison with data from 25 years ago indicated that isotopic compositions at some locations have become significantly less depleted in δ 18 O, suggesting that the contribution from irrigation water had increased. The study has demonstrated the importance of establishing good conceptual models at an early stage of such investigations, particularly where multiple and changing sources of groundwater recharge are anticipated. (author)
Using isotopes for design and monitoring of artificial recharge systems
Contributors: Hendriksson, N.; Kulongoski, J.T.; Massmann, G.; Newman, B.
2013-01-01
Over the past years, the IAEA has provided support to a number of Member States engaged in the implementation of hydrological projects dealing with the design and monitoring of artificial recharge ( A R ) systems, primarily situated in arid and semiarid regions. AR is defined as any engineered system designed to introduce water to, and store water in, underlying aquifers. Aquifer storage and recovery (ASR) is a specific type of AR used with the purpose of increasing groundwater resources. Different water management strategies have been tested under various geographical, hydrological and climatic regimes. However, the success of such schemes cannot easily be predicted, since many variables need to be taken into account in the early stages of every AR project.
Afrifa, George Yamoah; Sakyi, Patrick Asamoah; Chegbeleh, Larry Pax
2017-07-01
Sustainable development and the management of groundwater resources for optimal socio-economic development constitutes one of the most effective strategies for mitigating the effects of climate change in rural areas where poverty is a critical cause of environmental damage. This research assessed groundwater recharge and its spatial and temporal variations in Gushiegu District in the Northern Region of Ghana, where groundwater is the main source of water supply for most uses. Isotopic data of precipitation and groundwater were used to infer the origin of groundwater and the possible relationship between groundwater and surface water in the partially metamorphosed sedimentary aquifer system in the study area. Though the data do not significantly establish strong relation between groundwater and surface water, the study suggests that groundwater in the area is of meteoric origin. However, the data also indicate significant enrichment of the heavy isotopes (18O and 2H) in groundwater relative to rainwater in the area. The Chloride Mass Balance (CMB) and Water Table Fluctuations (WTF) techniques were used to quantitatively estimate the groundwater recharge in the area. The results suggest groundwater recharge in a range of 13.9 mm/y - 218 mm/y, with an average of 89 mm/yr, representing about 1.4%-21.8% (average 8.9%) of the annual precipitation in the area. There is no clearly defined trend in the temporal variations of groundwater recharge in the area, but the spatial variations are discussed in relation to the underlying lithologies. The results suggest that the fraction of precipitation that reaches the saturated zone as groundwater recharge is largely controlled by the vertical hydraulic conductivities of the material of the unsaturated zone. The vertical hydraulic conductivity coupled with humidity variations in the area modulates the vertical infiltration and percolation of precipitation.
El-Sayed, Salah Abdelwahab; Morsy, Samah M.; Zakaria, Khalid M.
2018-06-01
This study addresses the topic of recharge sources and evolution of groundwater in the Atfih area situated in the northeastern part of the Nile Valley, Egypt. Inventory of water wells and collection of groundwater and surface water samples have been achieved. Water samples are analyzed for major ions according to the American Society for Testing and Materials and for the environmental isotopes analysis (oxygen-18 and deuterium) by using a Triple Liquid Isotopic Water Analyzer (Los Gatos). The groundwater is available from the Quaternary aquifer formed mainly of graded sand and gravel interbedded with clay lenses. The hydrogeologic, hydrogeochemical and isotopic investigations indicate the hydrodynamic nature of the aquifer, where different flow paths, recharge sources and evolution mechanisms are distinguished. The directions of groundwater flow are from E, W and S directions suggesting the contribution from Nile River, the Eocene aquifer and the Nile basin, respectively. The groundwater altitudes range from 13 m (MSL) to 44 m (MSL). The hydraulic gradient varies between 0.025 and 0.0015. The groundwater is alkaline (pH > 7) and has salinity ranging from fresh to brackish water (TDS between 528 mg/l and 6070 mg/l). The observed wide range in the ionic composition and water types reflects the effect of different environmental and geological conditions through which the water has flowed. The isotopic compositions of groundwater samples vary between -14.13‰ and +23.56 for δD and between - 2.91‰ and +3.10 for δ18O. The isotopic data indicates that the Quaternary aquifer receive recharge from different sources including the Recent Nile water, surplus irrigation water, old Nile water before the construction of Aswan High Dam, surface runoff of local rains and Eocene aquifer. Evaporation, water rock interaction and mixing between different types of waters are the main processes in the groundwater evolution. Major suggestions are presented to develop the aquifer
International Nuclear Information System (INIS)
Daud bin Mohamad; Roslan bin Mohd Ali.
1981-02-01
A preliminary study of the isotope hydrology of the Lower Kelantan River Basin is presented. The overall aims of this investigation are to study the groundwater movement, re-charge areas, direction and flowrate and also to identify the recharge mechanism of the existing aquifers. The results show that all groundwater samples in the area vary within a narrow range for Oxygen-18 (-5.66 to -7.64) whilst isotope of Hydrogen -2 ranges from -34.1 to -48.8. The Kelantan River water contains -6.84 for Oxygen-18 and -45.0 for 2 H. Tritium data confirm that all groundwater samples of third aquifer is older than 25 years and most waters from the first and second aquifers are younger than 25 years. The isotopic data demonstrates that the first aquifer is recharged either by precipitation and/or river water in locations where high tritium and less negative 8-values are observed and by the third aquifer in locations with low tritium and more negative 8-values, the recharging of the second aquifer seems to be from the first and third aquifers as the second aquifer has 8-values ranging from those of the first and third aquifers; the recharge mechanism of the third aquifer cannot be established with the present data, a more detailed investigation is needed. From the chemical and isotopic results it seems that the salt content increases in waters are derived from leaching the aquifer matrix rather than from sea water intrusion. However, more wells and samples are expected to be collected in the second sampling programme in order to visualise clearly the regional hydrogeological system of the area. Nevertheless, some important conclusions that have been drawn from this study will be very useful as a guideline to further investigation and planning of groundwater management. (author)
van Geldern, Robert; Baier, Alfons; Subert, Hannah L; Kowol, Sigrid; Balk, Laura; Barth, Johannes A C
2014-10-15
Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ~20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. Copyright © 2014 Elsevier B.V. All rights reserved.
Using 14C and 3H to understand groundwater flow and recharge in an aquifer window
Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.
2014-12-01
Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr-1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower δ18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10
Groundwater salinity study in the Mekong Delta using isotope techniques
International Nuclear Information System (INIS)
Le Van Khoi, Nguyen Kien Chinh; Do Tien Hung
2002-01-01
Environmental isotopes D, 18 O and chemical composition were used for study of recharge and salinization of groundwater in the are located between Bassac and Mekong Rivers. The results showed that: (a) Pleistocene aquifers are recharged through flood plains and outcrops located at the same altitude. The sanility of groundwater in these aquifers is mostly due to dissolution of the aquifer material, (b) Pliocene and Miocene aquifers receive recharge through outcrops located at the higher altitude on the northeast extension of the Delta and Cambodia. The salinity of groundwater in the coastal region of the aquifer is attributable to sea water intrusion. There appears to be significant retention of sea water in the coastal sediment during intrusion. (Author)
Natural isotopes and water stratification in the Judea Group aquifer (Judea Desert)
International Nuclear Information System (INIS)
Kornfeld, Loel; Vogel, John C.; Rosenthal, Asher
1992-01-01
Using environmental isotopes, the subaquifer of the Judea Group carbonate aquifer were studied from the recharge area in the Judea Hills, eastwords down the flanks of the escarpment to the Jordan River Valley. The oxygen isotope data confirms that the dominant source of recharge for the phreatic and confined subaquifers in the Judean Hills. Water-rock interactions develop the δ 13 C values rapidly in the recharge region. once established where is no significant subsequent modification due to interaction with the enveloping carbonate as the water travels down dip. The relative high tritium values encountered in the springs and several of the well waters would indicate modern waters. However, the low radiocarbon levels are often encountered in the same water sources implies that a mixture of young water with significanly older water has been encountered. There are indications, at least in the upper subaquifer, of agewise stratification of the waters. Water is transmitted very rapidly through the upper portions of the aquifer while the water in the lower portions may be moving slowly because of the low permeability. The timing of the recharge of the deeper portion of the subaquifer and much of the lower subaquifer occurred in the mid-to early Holocene. (authors)
International Nuclear Information System (INIS)
Amro, H.; Kilani, S.; Jawawdeh, J.; Abd El-Din, I.; Rayan, M.
2001-01-01
The study of environmental chloride, deuterium and nitrate has been carried out in sand profiles in two locations in Jordan. The first location is in the Quaternary sediments and sandstones of Al Quwayra in southern Jordan where the average rainfall is less than 70 mm per year. The study concluded that there is no modern recharge in the studied site in southern Jordan. The second location is in the Kurnub sandstone outcrop near to Jarash in northern Jordan. The average rainfall in the area is 500 mm per year and thus significant recharge is possible in that area. The study showed that the annual recharge to the aquifer in that area is about 28 mm per year. The third location consists of four cores is in the alluvium Mudflat deposits of Azraq Oasis. The average rainfall in this area is about 67 mm per year which occur as storms between January and March. (author)
Ayadi, Rahma; Trabelsi, Rim; Zouari, Kamel; Saibi, Hakim; Itoi, Ryuichi; Khanfir, Hafedh
2017-12-01
Major element concentrations and stable (δ18O and δ2H) and radiogenic (3H and 14C) isotopes in groundwater have proved useful tracers for understanding the geochemical processes that control groundwater mineralization and for identifying recharge sources in the semi-arid region of Sfax (southeastern Tunisia). Major-ion chemical data indicate that the origins of the salinity in the groundwater are the water-rock interactions, mainly the dissolution of evaporitic minerals, as well as the cation exchange with clay minerals. The δ18O and δ2H relationships suggest variations in groundwater recharge mechanisms. Strong evaporation during recharge with limited rapid water infiltration is evident in the groundwater of the intermediate aquifer. The mixing with old groundwater in some areas explains the low stable isotope values of some groundwater samples. Groundwaters from the intermediate aquifer are classified into two main water types: Ca-Na-SO4 and Ca-Na-Cl-SO4. The high nitrate concentrations suggest an anthropogenic source of nitrogen contamination caused by intensive agricultural activities in the area. The stable isotopic signatures reveal three water groups: non-evaporated waters that indicate recharge by recent infiltrated water; evaporated waters that are characterized by relatively enriched δ18O and δ2H contents; and mixed groundwater (old/recent) or ancient groundwater, characterized by their depleted isotopic composition. Tritium data support the existence of recent limited recharge; however, other low tritium values are indicative of pre-nuclear recharge and/or mixing between pre-nuclear and contemporaneous recharge. The carbon-14 activities indicate that the groundwaters were mostly recharged under different climatic conditions during the cooler periods of the late Pleistocene and Holocene.
Environmental isotope study of groundwater systems in the Republic of Djibouti
International Nuclear Information System (INIS)
Fontes, J.Ch.; Saliege, J.F.; Zuppi, G.M.; Pouchan, P.
1980-01-01
Environmental isotopes and hydrogeochemistry are being used to shed new light on the occurrence of present-day recharge and on the origin of groundwater systems in the Republic of Djibouti. Furthermore, an attempt is also being made to evaluate palaeohydrological conditions during the past 6000 years. From stable isotope data which lie along a correlation line at a slope of 8 in the diagram delta 2 H-delta 18 O, it can be concluded that recharge occurs by rapid seepage in fractured rocks without evaporation. Some waters from hot springs show an oxygen shift, indicating the occurrence of an exchange process with rocks at high temperatures. The following conclusions can be reached from tritium and 14 C content of waters. Groundwaters can be divided into two groups: one deriving from recent recharge (last five or six years) corresponding to water with rather fast circulations in fractured media; and a second group, pre-bomb recharged corresponding to water with low flow rates in porous media. Only one sample (Yoboki) seems to derive from about 10-year-old recharge. In the case of Abhe hot spring, a 14 C age of about 1200 years may be evaluated. The calcite concretions of the Abhe Lake Basin are believed to have formed as a result of the mixing of lake water (sodium-carbonate type) with groundwater (sodium-chloride, calcium-sulphate type). From the 13 C and 14 C content it appears that the dissolved carbon of present-day lake water is in, or close to, equilibrium with the atmosphere. Consequently, it is assumed that such was also the case during the whole Holocene. The 18 O content of palaeolake water, evaluated from the calcite isotopic composition with the palaeo-temperature equation, was originally more negative than the present one. This is interpreted as due to the fact that the Holocene lake was fed by large floods and that significant seepage occurred through the lake bottom with a consequent reduction of the evaporation effects. (author)
Evaluation of TASTEX task H: measurement of plutonium isotopic abundances by gamma-ray spectrometry
International Nuclear Information System (INIS)
Gunnink, R.; Prindle, A.L.; Asakura, Y.; Masui, J.; Ishiguro, N.; Kawasaki, A.; Kataoka, S.
1981-10-01
This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables
Acheampong, S. Y.
2007-12-01
A critical component to managing water resources is understanding the source of ground water that is extracted from a well. Detail information on the source of recharge and the age of groundwater is thus vital for the proper assessment, development, management, and monitoring of the groundwater resources in an area. Great differences in the isotopic composition of groundwater in a basin and the basin precipitation imply that the groundwater in the basin originates from a source outside the basin or is recharged under different climatic conditions. The stable isotopes of oxygen and hydrogen in precipitation were compared with the isotopic composition of water from wells, springs, and creeks to evaluate the source of the shallow groundwater recharge in Spring and Snake Valleys, Nevada, as part of an evaluation of the water resources in the area. Delta deuterium and delta oxygen-18 composition of springs, wells, creeks, and precipitation in Spring and Snake Valleys show that groundwater recharge occurs primarily from winter precipitation in the surrounding mountains. The carbon-14 content of the groundwater ranged from 30 to 95 percent modern carbon (pmc). Twenty two of the thirty samples had carbon-14 values of greater than 50 pmc. The relatively high carbon-14 values suggest that groundwater in the area is recharged by modern precipitation and the waters have rapid travel times. Total dissolved solids content of the samples outside the playa areas are generally low, and suggests that the water has a relatively short travel time between the recharge areas and sample sites. The presence of tritium in some of the springs and wells also indicate that groundwater mixes with post 1952 precipitation. Hydrogen bomb tests which began in 1952 in the northern hemisphere added large amounts of tritium to the atmosphere and reached a peak in 1963. The stable isotopic composition, the high carbon-14 activities, and the presence of tritium, show that the shallow groundwater in
Groundwater recharge in the tropics: a pan-African analysis of observations
Taylor, R. G.
2015-12-01
Groundwater is a vital source of freshwater in sub-Saharan Africa where rainfall and river discharge are unreliable and per-capita reservoir storage is among the lowest in the world. Groundwater is widely considered a distributed, low-cost and climate-resilient option to meet rapidly growing freshwater demand and alleviate endemic poverty by expanding access to safe water and improving food security through irrigation. Recent research indicates that groundwater storage in Africa is about 100 times greater than annual river discharge yet major uncertainties remain in the magnitude and nature of replenishment through recharge as well as the impacts of land-use and climate change. Here, we present newly compiled, multi-decadal observations of groundwater levels from 5 countries (Benin, Burkina Faso, Niger, Tanzania, Uganda) and paired measurements of stable isotope ratios of O and H in precipitation and groundwater at 11 locations. These data reveal both a distinct bias in groundwater recharge to intensive rainfall and rapid recharge pathways (e.g. focused, macropore flow) that are inconsistent with conventional recharge models assuming pore-matrix flow defined by the Darcy-Richards equation. Further the records highlight the substantial influence of land-use change (e.g. conversion of natural, perennial cover to croplands) on groundwater recharge. The compiled observations also provide, for the first time, a pan-African baseline to evaluate the performance of large-scale hydrological models and Land-Surface Models incorporating groundwater in this region. Our results suggest that the intensification of precipitation brought about by global warming favours groundwater replenishment in sub-Saharan Africa. As such, groundwater may prove to be a climate-resilient source of freshwater in the tropics, enabling adaptive strategies such as groundwater-fed irrigation and sustaining domestic and industrial water supplies.
Age of underground waters: isotopes contribution
International Nuclear Information System (INIS)
Chery, L.; Olive, Ph.
2006-01-01
Does water has an age? The age of underground waters can be the duration of their underground travel between their infiltration inside the ground and their captation at a spring or a drilled well. The isotopic geochemistry comes to the support of classical geochemistry to estimate these residence times. Radio-isotopes, like tritium for young waters or carbon 14 for old waters, are used as chronometers to interpret the recharge ways, the flow mechanisms and the residence times of underground waters. Their use is presented in this article with some theoretical recalls and some examples of application. (J.S.)
Combined stable isotope trajectories for water-rock interaction
International Nuclear Information System (INIS)
Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt
1981-01-01
The 'mixed' model of water-rock interaction (1980 Workshop) is explained in detail. Based on the magnitude of the oxygen isotope shifts of their recharge water, different geothermal systems can be placed in an evolutionary series, from incipient (large shift of water) to mature (small shift of water). Isotopes of different chemical elements may be combined, to yield a stringent test of whether or not a given change in rock composition may be ascribed to interaction with water (L-shaped trajectories). For the acidic eruptives of the Taupo Volcanic Zone, available strontium and oxygen isotope data practically rule out an origin by partial melting of greywacke basement
International Nuclear Information System (INIS)
Duvert, Clément; Raiber, Matthias; Owen, Daniel D.R.; Cendón, Dioni I.; Batiot-Guilhe, Christelle; Cox, Malcolm E.
2015-01-01
Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO 3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO 3 –Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment
Residence Times in Central Valley Aquifers Recharged by Dammed Rivers
Loustale, M.; Paukert Vankeuren, A. N.; Visser, A.
2017-12-01
Groundwater is a vital resource for California, providing between 30-60% of the state's water supply. Recent emphasis on groundwater sustainability has induced a push to characterize recharge rates and residence times for high priority aquifers, including most aquifers in California's Central Valley. Flows in almost all rivers from the western Sierra to the Central Valley are controlled by dams, altering natural flow patterns and recharge to local aquifers. In eastern Sacramento, unconfined and confined shallow aquifers (depth recharged by a losing reach of the Lower American River, despite the presence of levees with slurry cut-off walls.1 Flow in the Lower American River is controlled through the operation of the Folsom and Nimbus Dams, with a minimum flow of 500 cfs. Water table elevation in wells in close proximity to the river are compared to river stage to determine the effect of river stage on groundwater recharge rates. Additionally, Tritium-3Helium dates and stable isotopes (∂18O and ∂2H) have been measured in monitoring wells 200- 2400 ft lateral distance from the river, and depths of 25 -225 feet BGS. Variation in groundwater age in the vertical and horizontal directions are used to determine groundwater flow path and velocity. These data are then used to calculate residence time of groundwater in the unconfined and confined aquifer systems for the Central Valley in eastern Sacramento. Applying groundwater age tracers can benefit future compliance metrics of the California Sustainable Groundwater Resources Act (SGMA), by quantifying river seepage rates and impacts of groundwater management on surface water resources. 1Moran et al., UCRL-TR-203258, 2004.
Borisova, Anastassia Y.; Bohrson, Wendy A.; Grégoire, Michel
2017-07-01
Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine-hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open-system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy-constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21-19 Ma basaltic series, the most primitive series ever found among the Kerguelen OIBs, we performed sixty-seven simulations in the pressure range from 0.2 to 1.0 GPa using compositions of olivine-hosted melt inclusions as parental magmas, and metagabbro xenoliths from the Kerguelen Archipelago as wallrock. MCS modeling requires that the assimilant is anatectic crustal melts (P2O5 ≤ 0.4 wt.% contents) derived from the Kerguelen oceanic metagabbro wallrock. To best fit the phenocryst assemblage observed in the investigated basaltic series, recharge of relatively large masses of hydrous primitive basaltic melts (H2O = 2-3 wt%; MgO = 7-10 wt.%) into a middle crustal chamber at 0.2 to 0.3 GPa is required. Our results thus highlight the important impact that crustal gabbro assimilation and mantle recharge can have on the geochemistry of mantle-derived olivine-phyric OIBs. The importance of crustal assimilation affecting primitive plume-derived basaltic melts underscores that isotopic and chemical equilibrium between ocean island basalts and associated deep plume mantle source(s) may be the exception rather than the rule.
International Nuclear Information System (INIS)
Stewart, M.K.; Dicker, M.J.I.; Johnston, M.R.
1981-01-01
Oxygen isotope measurements of ground and surface waters of the Waimea Plains, Nelson, have been used to identify sources of water in aquifers beneath the plains. Major rivers flowing onto the plains are from higher-altitude catchments (maximum altitude 2000 m) and have delta O 18 approximately equal to -7.2%, whereas rainfall on the plains and adjacent low-altitude catchment streams have delta O 18 approximately equal to -6.2%. The delta O 18 measurements indicate that the 3 major aquifer units, the ''Lower Confined Aquifers'' and the ''Upper Confined Aquifers'' in the Hope Gravel (Late Pleistocene) and the ''Unconfined Aquifers'' in the Appleby Gravel (Holocene) are recharged from different sources. The ''Lower Confined Aquifers'' probably receive slow recharge in the south near Brightwater. The ''Upper Confined Aquifers'' are recharged, in the south, from the Wairoa River and locally in the north are connected with the unconfined aquifers. The ''Unconfined Aquifers'' are recharged from the Waimea River and, away from the river, from rainfall. Intermixing of water, via multiple screened wells, between the various aquifers is also indicated. (author). 5 refs., 5 figs., 1 tab
Directory of Open Access Journals (Sweden)
Nara Somaratne
2015-02-01
Full Text Available The article “Karst aquifer recharge: Comments on ‘Characteristics of Point Recharge in Karst Aquifers’, by Adrian D. Werner, 2014, Water 6, doi:10.3390/w6123727” provides misrepresentation in some parts of Somaratne [1]. The description of Uley South Quaternary Limestone (QL as unconsolidated or poorly consolidated aeolianite sediments with the presence of well-mixed groundwater in Uley South [2] appears unsubstantiated. Examination of 98 lithological descriptions with corresponding drillers’ logs show only two wells containing bands of unconsolidated sediments. In Uley South basin, about 70% of salinity profiles obtained by electrical conductivity (EC logging from monitoring wells show stratification. The central and north central areas of the basin receive leakage from the Tertiary Sand (TS aquifer thereby influencing QL groundwater characteristics, such as chemistry, age and isotope composition. The presence of conduit pathways is evident in salinity profiles taken away from TS water affected areas. Pumping tests derived aquifer parameters show strong heterogeneity, a typical characteristic of karst aquifers. Uley South QL aquifer recharge is derived from three sources; diffuse recharge, point recharge from sinkholes and continuous leakage of TS water. This limits application of recharge estimation methods, such as the conventional chloride mass balance (CMB as the basic premise of the CMB is violated. The conventional CMB is not suitable for accounting chloride mass balance in groundwater systems displaying extreme range of chloride concentrations and complex mixing [3]. Over simplification of karst aquifer systems to suit application of the conventional CMB or 1-D unsaturated modelling as described in Werner [2], is not suitable use of these recharge estimation methods.
Isotope techniques in water resource investigations in arid and semi-arid regions
International Nuclear Information System (INIS)
2001-03-01
The Co-ordinated Research Project (CRP) on the Use of Isotope Techniques in Water Resources Investigations in Arid and Semi-arid Regions was initiated with the aim od contributing to the assessment of groundwater resources in arid areas through the use of environmental isotope techniques, and thereby to help in better management of these valuable fresh groundwater resources. The main emphases identified were in three key areas: (i) the evaluation of water balance components such as recharge rate estimation and recharge and discharge cycles at different spatial scales, (ii) paleohydrology and hydroclimatic change and, (iii) anthropogenic impacts and the assessment of the vulnerability of arid zone ground waters to salinisation and pollution impacts. This publication presents individual projects carried out within the frameworks of the CRP. Each paper has been indexed separately
Progress in aqueous rechargeable batteries
Jilei Liu; Chaohe Xu; Zhen Chen; Shibing Ni; Ze Xiang Shen
2018-01-01
Over the past decades, a series of aqueous rechargeable batteries (ARBs) were explored, investigated and demonstrated. Among them, aqueous rechargeable alkali-metal ion (Li+, Na+, K+) batteries, aqueous rechargeable-metal ion (Zn2+, Mg2+, Ca2+, Al3+) batteries and aqueous rechargeable hybrid batteries are standing out due to peculiar properties. In this review, we focus on the fundamental basics of these batteries, and discuss the scientific and/or technological achievements and challenges. B...
A validation of the 3H/3He method for determining groundwater recharge
Solomon, D. K.; Schiff, S. L.; Poreda, R. J.; Clarke, W. B.
1993-09-01
Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s 3H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing 3H and its stable daughter 3He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the 3H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero 3H/3He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the 3H peak (and hence the vertical velocity) is also well-defined, the 3H/3He results could not be used to compute recharge because samples were not collected sufficiently far above the 3H peak; however, modeling indicates that the 3H/3He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because 3H and 3He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for 3H (3HHO) and 3He of 2.4×10-5 and 1.3×10-4 m2/day, respectively. Although the 3H/3He age gradient is an excellent indicator of vertical groundwater velocities above the mid-1960s 3H peak, dispersive mixing and diffusive loss of 3He perturb the age gradient near and below the 3H peak.
Heilweil, V.M.; Solomon, K.D.; Gingerich, S.B.; Verstraeten, Ingrid M.
2009-01-01
Stable isotopes (??18O, ??2H), tritium (3H), and helium isotopes (3He, 4He) were used for evaluating groundwater recharge sources, flow paths, and residence times of three watersheds in the Cape Verde Islands (West Africa). Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. In contrast to other active oceanic hotspots, environmental tracers show that deep geothermal circulation does not strongly affect groundwater. Low tritium concentrations at seven groundwater sites indicate groundwater residence times of more than 50 years. Higher tritium values at other sites suggest some recent recharge. High 4He and 3He/4He ratios precluded 3H/3He dating at six sites. These high 3He/4He ratios (R/Ra values of up to 8.3) are consistent with reported mantle derived helium of oceanic island basalts in Cape Verde and provided end-member constraints for improved dating at seven other locations. Tritium and 3H/3He dating shows that S??o Nicolau Island's Ribeira Faj?? Basin has groundwater residence times of more than 50 years, whereas Fogo Island's Mosteiros Basin and Santo Ant??o Island's Ribeira Paul Basin contain a mixture of young and old groundwater. Young ages at selected sites within these two basins indicate local recharge and potential groundwater susceptibility to surface contamination and/or salt-water intrusion. ?? Springer-Verlag 2009.
International Nuclear Information System (INIS)
Iffatul Izza Siftianida; Agus Budhie Wijatna; Bungkus Pratikno
2016-01-01
Spring as a source of groundwater in Cijeruk district exploited by local people and water companies. Excessive use of water causes lack of water during dry season. Conservation of recharge areas to maintain the availability of water to supply the water demand. Determination of location recharge areas and chemical analysis of groundwater needs to be done to provide required information to conserve the recharge area. Therefore, this study aims: (1) determine the origin of groundwater, (2) determine recharge area, (3) identify facies of groundwater, and (4) identify the quality of groundwater. Sampling was done in Cijeruk, groundwater samples were collected from 10 locations that were used by water companies and local people in May 2015. The ratio of isotopes δD and δ "1"8O in water samples was measured by liquid water stable isotope analyzer LGR DLT-100 to determine the genesis of groundwater and recharge area. Hydrochemical facies analysis to determine groundwater quality. Chemical parameters used are pH, electrical conductivity (EC), Total Dissolved Solid (TDS), and major ions. The results showed: (a) spring origin from several sources suck as rainwater and groundwater, (b) recharge area of CJR01, CJR02, CJR03, and CJR04 located on elevation of 1988 to 2055 m.dpl, (c) recharge area of CJR06 and CJR09 on elevation 1379 - 1430 m.dpl, (d) recharge area of CJR08 and CJR07 on elevation of 811-836 m.dpl, (e) recharge area of CJR05 and CJR10, each located on elevation of 1475 m.dpl, and 1932 m.dpl, (f) the groundwater facies is Mg-HCO_3 (magnesium bicarbonate), and (g) the quality of groundwater is fresh water. (author)
International Nuclear Information System (INIS)
Al-Sagaby, A.; Moallim, A.
2001-01-01
The investigation of recharge in the sand dune, Qasim, Saudi Arabia, with the help of chloride concentration and isotope content has revealed inconsistent pattern and less homogeneity. Monotonic chloride concentration and isotope content was the result of seasonal recharge occurrence in the study area. In addition, applying chloride mass-balance method, recharge rate calculation in the sand dune site, Qasim, Saudi Arabia, was made. The results (1.80 and 1.84mmy -1 - dune site) estimated during this project using this method was a long way below the recharge rates (30mmy -1 , 13.4mmy -1 in the dune site and 5mmy -1 in the swale site) obtained with the application of tritium method in the previous years (1994 and 1996). 1.80 and 1.84mmy -1 was for CRP-Saud-9405 project and was calculated 1997 and 1998 respectively. The reason for the lower recharge rate with the application of chloride mass-balance method could be the source of chloride input and high evaporation, which causes accumulation of chloride salts in the area. (author)
Evaluation of the ''Sabana de Bogota'' aquifer using isotopes techniques
International Nuclear Information System (INIS)
Torres, E.; Jimenez, G.; Obando, E.; Sanchez, L.; Alayon, E.
1987-01-01
Groundwater from the Sabana de Bogota area was studied by means of isotopic techniques such as isotope analysis, injection of tracers for determination of hydrogeological parameters, velocity measurements using tracers. These results combined with the ones obtained by conventional techniques were used to determine recharge area, origin, equipotencial lines and direction of groundwater. The results show that a combined application of classical and nuclear methods may establish rather reasonable hydrogeological concepts without investing much time and money
Isotope characteristics of groundwater in Beishan area
International Nuclear Information System (INIS)
Guo Yonghai; Liu Shufen; Lu Chuanhe
2004-01-01
Using the isotope techniques, the authors studied the origin, evolution and circulation of the groundwater in the potential site of China's high-level waste repository. The results indicate that both deep groundwater and shallow groundwater are mainly recharged by modern and local precipitation, and the deep groundwater in the site area is of meteoric origin. The shallow groundwater is mainly recharged by modern and local precipitation, and the deep groundwater originates from regional precipitation at higher elevation, or might be derived from the precipitation during the geological period of lower temperature. It is also known from the study that the deep underground is a system of very low-permeability where the groundwater flow rates are very low. (author)
Isotopic study of the effect of Tarbela reservoir on the groundwater system in the downstream areas
International Nuclear Information System (INIS)
Sajjad, M.I.; Tasneem, M.A.; Hussain, S.D.; Khan, I.H.; Ali, M.; Latif, Z.
1994-04-01
Isotopic studies were carried out on the right side of river Indus, downstream of Tarbela dam to study the effect of Tarbela Reservoir on the groundwater system. The main objectives of the study were to determine the hydraulic connection, if any, between the Tarbela Lake and the groundwater appearing in the ponds near Gadon Amazai, see the effect of Tarbela dam on the groundwater system in the downstream areas, compute the relative contribution of different recharge sources towards groundwater system and to estimate residence time of groundwater in the area. Isotopic data reveals that the ponds near Gadoon Amazai area are being recharged by local rains and there is no contribution of Tarbela lake. The area around Gadoon Amazai, Topi and Kalabat is solely recharged by local rains while the area around Swabi, Zaida and Lahor has mixed recharge with major contribution from local canal system. Tritium data suggests that the residence time of groundwater in the study area varies from a few years to 30 years. Te groundwater in the area has low dissolved salt contents and is, generally, of good quality. (author) 19 figs
Precipitation, flood- and groundwaters of the Negev highlands. An isotopic study of desert hydrology
International Nuclear Information System (INIS)
Levin, M.; Issar, A.
1980-01-01
Precipitation in the Negev highlands was found to be surprisingly depleted of 18 O and deuterium and generally characterized by ''deuterium excess'' values of d>15per mille. Isotopic compositions are relatively uniform over a wide area on any particular day, but differ appreciably from storm to storm. Thus, they are valuable tools for hydrographic analysis of flood-flows. Flood-flow samples, collected in Nahal-Zin and Nahal-Besor, were often even more depleted in heavy isotopes than the total rainstorm, indicating that run-off is generated selectively by high-intensity rains. The initial rush of the flood flushed away the surface salinity and saline accumulations in surface pools, but apparently does not involve sub-surface salinity to any great extent. Recharge to groundwater appears to be accompanied by a slight evaporative enrichment of the isotopes, more so in the case of waters recharged from flood-flows. Environmental tritium can be used as an indicator of direct flood-water contributions to the aquifers. (author)
Isotope and chemical tracers in groundwater hydrology
International Nuclear Information System (INIS)
Kendall, C.; Stewart, M.K.; Morgenstern, U.; Trompetter, V.
1999-01-01
The course sessions cover: session 1, Fundamentals of stable and radioactive isotopes; session 2, Stable oxygen and hydrogen isotopes in hydrology: background, examples, sampling strategy; session 3, Catchment studies using oxygen and hydrogen isotopes: background - the hydrologic water balance, evapotranspiration - the lion's share, runoff generation - new water/old water fractions, groundwater recharge - the crumbs; session 4, Isotopes in catchment hydrology: survey of applications, future developments; session 5, Applications of tritium in hydrology: background and measurement, interpretation, examples; session 6, Case studies using mixing models: Hutt Valley groundwater system, an extended mixing model for simulating tracer transport in the unsaturated zone; session 7, Groundwater dating using CFC concentrations: background, sampling and measurement, use and applications; session 8, Groundwater dating with carbon-14: background, sampling and measurement, use and applications; session 9, NZ case studies: Tauranga warm springs, North Canterbury Plains groundwater; session 10, Stable carbon and nitrogen isotopes: background and examples, biological applications of C-N-S isotopes; session 11, New developments in isotope hydrology: gas isotopes, compound specific applications, age dating of sediments etc; session 12, NZ case studies: North Canterbury Plains groundwater (continued), Waimea Plains groundwater. (author). refs., figs
Water flow and solute transport using environmental isotopes and modeling
International Nuclear Information System (INIS)
Hussein, M.F.
2001-01-01
The deep unsaturated zone may be a useful hydrological archive in desert environments characterized by scant or sporadic rainfall and slow percolation of rainwater over decades or even centuries. This moisture archive provides a useful way to distinguish the net downward flow of recharge water, whereas the isotopic composition and concentration of the conservative solutes of the preserved moisture could be used to reconstruct the history of recharge under the prevailing deficient water balance. The major advantage of such coupled approach is to obtain independent estimates of groundwater recharge rates which are normally difficult to evaluate using the hydrological methods applied in the temperate zones. The study was conducted in the Shiekh-Zoweid/Raffa area in the northeastern coastal strip of Sinai Peninsula. Bore-holes were dry-drilled in a line perpendicular to the sea shoreline (using an 8-inch diameter hand-operated rotary rig) for the unsaturated sediment collection from successive 0.5m thick layers down to a depth of 20m. Samples were investigated for the moisture contents and the chemical and isotope composition of this moisture was determined. Physical parameters were also assessed including porosity and volumetric moisture content. Chloride mass-balance was used to calculate recharge rates through the unsaturated zone by predicting the position of the 1963-Tritium peak in the unsaturated column. Analysis of moisture, chloride and deuterium profiles showed three principle peaks (along with minor ones) in Karafin site indicating few major recharge events that have taken place during the last few decades. Adjustment of these episodes has also been attempted using two historical major rainfall events (known from nearby meteorological stations). Application of the methodology in water resources management in arid regions is discussed. (author)
Coes, A.L.; Pool, D.R.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.
2007-01-01
The timing and location of streamflow in the San Pedro River are partially dependent on the aerial distribution of recharge in the Sierra Vista subwatershed. Previous investigators have assumed that recharge in the subwatershed occurs only along the mountain fronts by way of stream-channel infiltration near the contact between low-permeability rocks of the mountains and the basin fill. Recent studies in other alluvial basins of the Southwestern United States, however, have shown that significant recharge can occur through the sediments of ephemeral stream channels at locations several kilometers distant from the mountains. The purpose of this study was to characterize the spatial distribution of infiltration and subsequent recharge through the ephemeral channels in the Sierra Vista subwatershed.Infiltration fluxes in ephemeral channels and through the basin floor of the subwatershed were estimated by using several methods. Data collected during the drilling and coring of 16 boreholes included physical, thermal, and hydraulic properties of sediments; chloride concentrations of sediments; and pore-water stable-isotope values and tritium activity. Surface and subsurface sediment temperatures were continuously measured at each borehole.Twelve boreholes were drilled in five ephemeral stream channels to estimate infiltration within ephemeral channels. Active infiltration was verified to at least 20 meters at 11 of the 12 borehole sites on the basis of low sediment-chloride concentrations, high soil-water contents, and pore-water tritium activity similar to present-day precipitation. Consolidated sediments at the twelfth site prevented core recovery and estimation of infiltration. Analytical and numerical methods were applied to determine the surface infiltration flux required to produce the observed sediment-temperature fluctuations at six sites. Infiltration fluxes were determined for summer ephemeral flow events only because no winter flows were recorded at the sites
Kuroda, Keisuke; Hayashi, Takeshi; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Funabiki, Ayako; Takizawa, Satoshi
2017-05-01
Over-exploited groundwater is expected to remain the predominant source of domestic water in suburban areas of Hanoi, Vietnam. In order to evaluate the effect on groundwater recharge, of decreasing surface-water bodies and land-use change caused by urbanization, the relevant groundwater systems and recharge pathways must be characterized in detail. To this end, water levels and water quality were monitored for 3 years regarding groundwater and adjacent surface-water bodies, at two typical suburban sites in Hanoi. Stable isotope (δ18O, δD of water) analysis and hydrochemical analysis showed that the water from both aquifers and aquitards, including the groundwater obtained from both the monitoring wells and the neighboring household tubewells, was largely derived from evaporation-affected surface-water bodies (e.g., ponds, irrigated farmlands) rather than from rivers. The water-level monitoring results suggested distinct local-scale flow systems for both a Holocene unconfined aquifer (HUA) and Pleistocene confined aquifer (PCA). That is, in the case of the HUA, lateral recharge through the aquifer from neighboring ponds and/or irrigated farmlands appeared to be dominant, rather than recharge by vertical rainwater infiltration. In the case of the PCA, recharge by the above-lying HUA, through areas where the aquitard separating the two aquifers was relatively thin or nonexistent, was suggested. As the decrease in the local surface-water bodies will likely reduce the groundwater recharge, maintaining and enhancing this recharge (through preservation of the surface-water bodies) is considered as essential for the sustainable use of groundwater in the area.
Isotope techniques in water resources development 1991
International Nuclear Information System (INIS)
1992-01-01
Water resources are scarce in many parts of the world. Often, the only water resource is groundwater. Overuse usually invites a rapid decline in groundwater resources which are recharged insufficiently, or not at all, by prevailing climatic conditions. These and other problems currently encountered in hydrology and associated environmental fields have prompted an increasing demand for the utilization of isotope methods. Such methods have been recognized as being indispensable for solving problems such as the identification of pollution sources, characterization of palaeowater resources, evaluation of recharge and evaporative discharge under arid and semi-arid conditions, reconstruction of past climates, study of the interrelationships between surface and groundwater, dating of groundwater and validation of contaminant transport models. Moreover, in combination with other hydrogeological and geochemical methods, isotope techniques can provide useful hydrological information, such as data on the origin, replenishment and dynamics of groundwater. It was against this background that the International Atomic Energy Agency, in co-operation with the United Nations Educational, Scientific and Cultural Organization and the International Association of Hydrological Sciences, organized this symposium on the Use of Isotope Techniques in Water Resources Development, which took place in Vienna from 11 to 15 March 1991. The main themes of the symposium were the use of isotope techniques in solving practical problems of water resources assessment and development, particularly with respect to groundwater protection, and in studying environmental problems related to water, including palaeohydrological and palaeoclimatological problems. A substantial part of the oral presentations was concerned with the present state and trends in groundwater dating, and with some methodological aspects. These proceedings contain the papers of 37 oral and the extended synopses of 47 poster
isotopic characteristics of aquifers in sinai
International Nuclear Information System (INIS)
Al-Gamal, S.A.
2004-01-01
the environmental isotopes data (expressed as δ 2 d and δ 18 O) of different aquifers in sinai were treated using correlation and regression techniques. whereas, rain water isotopic data were treated using empirical orthogonal functions (EOF) techniques. environmental isotopes for different aquifers expressed in terms of O-18 and H-2, were taken to represent the isotopic characteristics. regression equations using the highly correlated variables of δ 2 d and δ 18 O were constructed for each aquifer. the latitudinal variations (of rainwater in sinai and selected climatic stations east mediterranean ) versus rainwater isotopic compositions were analyzed using the normalized variables. it was found that the latitudinal variations of the rainwater isotopic compositions ( δ 2 D, δ 18 O), vapor pressure, and surface temperature occurred in parallel and decreased with latitude. in the east mediterranean, empirical linear relationship between altitude and δ 2 D has indicted that the rate of change of δ 2 D with height is comparable with the dry lapse rate in the atmosphere.The obtained regression equations of environmental isotopes data have impacted on different slopes and different constants expressing the non-homogeneity in the isotopic composition of rainwater recharging the aquifers of sinai , due to the presence of different air masses
Linking denitrification and infiltration rates during managed groundwater recharge.
Schmidt, Calla M; Fisher, Andrew T; Racz, Andrew J; Lockwood, Brian S; Huertos, Marc Los
2011-11-15
We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress. Zero order denitrification rates between 3 and 300 μmol L(-1) d(-1) were measured during infiltration. Denitrification was not detected at times and locations where the infiltration rate exceeded a threshold of 0.7 ± 0.2 m d(-1). Pore water profiles of oxygen and nitrate concentration indicated a deepening of the redoxocline at high flow rates, which reduced the thickness of the zone favorable for denitrification. Denitrification rates were positively correlated with infiltration rates below the infiltration threshold, suggesting that for a given set of sediment characteristics, there is an optimal infiltration rate for achieving maximum nitrate load reduction and improvements to water supply during managed groundwater recharge. The extent to which results from this study may be extended to other managed and natural hydrologic settings remains to be determined, but the approach taken in this study should be broadly applicable, and provides a quantitative link between shallow hydrologic and biogeochemical processes.
Vadose Zone Infiltration Rates from Sr isotope Measurements
Maher, K.; Maher, K.; DePaolo, D. J.; DePaolo, D. J.; Conrad, M.
2001-12-01
Predicting infiltration rates and recharge through the vadose zone in arid regions is difficult and hence developing methods for the measurement of infiltration rates is important. We have been investigating the use of Sr isotope measurements for determining infiltration at the 200 Area plateau on the Hanford reservation in central Washington. In this context, infiltration affects the transport of contaminants to the water table as well as recharge of the groundwater system. Using Sr isotopes for this purpose requires drill core and water samples from the vadose zone, although leaches of the cores can substitute for water samples. Complementary information, including some constraints on regional recharge, can also be obtained using water samples from groundwater monitoring wells. The VZ method is based on the fact that the Sr isotope ratio of soil water just below the surface is often set by dissolution of aeolian material including carbonate, and this ratio is different from the average value in the deeper underlying vadose zone rock matrix. As water infiltrates, the Sr isotopic composition of the water changes toward the rock values as a result of Sr released from the rocks by weathering reactions. The rate of change with depth of the Sr isotope ratio of the vadose zone water is a function ultimately of q/R; the ratio of the infiltration flux (q) to the bulk rock weathering rate (R). Where it is possible to evaluate R, q can be estimated. As data accumulate it may be possible to improve the calibration of the method. At Hanford the vadose zone rock material is mostly unconsolidated sand, silt, and gravel of broadly granitic composition, which constitute the Hanford and Ringold formations. Annual precipitation is about 160 mm/yr. Drilling and coring of a ca. 70m hole to the water table in 1999 as part of the Hanford groundwater monitoring program, in a relatively undisturbed area of the site, allowed us to generate a unique Sr isotope data set. The Sr isotope
Isotopic hydrological studies carried out on the Karst water system
International Nuclear Information System (INIS)
Longinelli, A.
1988-03-01
The isotopic composition and temperature of many karst springs in the area of Trieste (Italy) have been measured for about three and a half years. During the same period the isotopic composition of precipitation has also been systematically studied. The isotopic composition of springs generally shows variations which are markedly shifted in time with respect to those of precipitation. In most of the springs the heavy isotope contents of winter samples are the highest of the whole year. On the contrary, summer samples normally show quite negative δ-values, the most negative of which often refer to the last summer months. The data obtained are explained in terms of variable mixing of waters from two main reservoirs. The less negative reservoir (in terms of δ) is recharged by ''local'' meteoric waters falling on the westernmost section of the karst area whose mean elevation is about 400 m a.s.l. The most negative reservoir is probably recharged by meteoric waters falling on the Slovenian section of the karst, whose mean elevation is about 800-900 m a.s.l. At least in the case of some of the northernmost karst springs, it is likely that a third water system, basically fed by the Isonzo river, flowing north of the karst area, could interfere with the previously mentioned reservoirs, partially controlling the outflow of some springs. 6 figs
Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie
2017-02-01
Groundwater recharge variations in time and space are crucial for effective water management, especially in low-precipitation regions. To determine comprehensive groundwater recharge processes in a catchment with large seasonal hydrological variations, intensive field surveys were conducted in the Wangkuai Reservoir watershed located in the Taihang Mountains, North China, during three different times of the year: beginning of the rainy season (June 2011), mid-rainy season (August 2012), and dry season (November 2012). Oxygen and hydrogen isotope and chemical analyses were conducted on the groundwater, spring water, stream water, and reservoir water of the Wangkuai Reservoir watershed. The results were processed using endmember mixing analysis to determine the amount of contribution of the groundwater recharging processes. Similar isotopic and chemical signatures between the surface water and groundwater in the target area indicate that the surface water in the mountain-plain transitional area and the Wangkuai Reservoir are the principal groundwater recharge sources, which result from the highly permeable geological structure of the target area and perennial large-scale surface water, respectively. Additionally, the widespread and significant effect of the diffuse groundwater recharge on the Wangkuai Reservoir was confirmed with the deuterium (d) excess indicator and the high contribution throughout the year, calculated using endmember mixing analysis. Conversely, the contribution of the stream water to the groundwater recharge in the mountain-plain transitional area clearly decreases from the beginning of the rainy season to the mid-rainy season, whereas that of the precipitation increases. This suggests that the main groundwater recharge source shifts from stream water to episodic/continuous heavy precipitation in the mid-rainy season. In other words, the surface water and precipitation commonly affect the groundwater recharge in the rainy season, whereas the
Cuthbert, M. O.; Acworth, R. I.; Andersen, M. S.; Larsen, J. R.; McCallum, A. M.; Rau, G. C.; Tellam, J. H.
2016-02-01
Understanding and managing groundwater resources in drylands is a challenging task, but one that is globally important. The dominant process for dryland groundwater recharge is thought to be as focused, indirect recharge from ephemeral stream losses. However, there is a global paucity of data for understanding and quantifying this process and transferable techniques for quantifying groundwater recharge in such contexts are lacking. Here we develop a generalized conceptual model for understanding water table and groundwater head fluctuations due to recharge from episodic events within ephemeral streams. By accounting for the recession characteristics of a groundwater hydrograph, we present a simple but powerful new water table fluctuation approach to quantify focused, indirect recharge over both long term and event time scales. The technique is demonstrated using a new, and globally unparalleled, set of groundwater observations from an ephemeral stream catchment located in NSW, Australia. We find that, following episodic streamflow events down a predominantly dry channel system, groundwater head fluctuations are controlled by pressure redistribution operating at three time scales from vertical flow (days to weeks), transverse flow perpendicular to the stream (weeks to months), and longitudinal flow parallel to the stream (years to decades). In relative terms, indirect recharge decreases almost linearly away from the mountain front, both in discrete monitored events as well as in the long-term average. In absolute terms, the estimated indirect recharge varies from 80 to 30 mm/a with the main uncertainty in these values stemming from uncertainty in the catchment-scale hydraulic properties.
International Nuclear Information System (INIS)
Zagloul, A.; Elewa, H.H.; Abd El-Samie, S.G.
2000-01-01
Hydrochemical and the isotope hydrological studies were carried out on four main aquifers in Halaib and Shalatein areas (Basement, Nubian- Sabdstone, Miocene and Quaternar aquifers) from which water samples were examined for detecting the origin, water type and the rechargeable to these aquifers. The genesis of the groundwater in the Basement aquifer in the north-west direction are NaHCO 3 and Na 2 SO 4 which changed to MgCl 2 near the coast. Its isotopic data indicate that rain water is the possible recharge source to this aquifer. The water genesis of the Nubian Sandstone aquifer is NgCI 2 in the flowing springs and Na 2 SO 4 in the deep wells. The range of isotopic depletion values with low salt content show a mixing of palaeo-rain water. In the Miocene and the Quaternary aquifers, CaCI 2 is the groundwater genesis with high dissolved solids and enriched isotopic content suggest that sea water is intrusion and dissolution of lagoons salts
Directory of Open Access Journals (Sweden)
Maurizio Barbieri
2014-06-01
Full Text Available The strontium isotopic ratio (expressed as 87Sr/86Sr of groundwater represents a useful method for studying and understanding the groundwater circulations, also, the U and Ra isotopic compositions can vary as function of the groundwater residence time. This paper reports an evaluation of the probable recharge area of the Sangemini mineral water springs (Terni-Umbria Central Italy and an estimate of the residence time of the aquifer by coupling Sr and U series isotopic systematics. For this study have been analyzed four water sample for the isotope ratio of 87Sr/86Sr, and eleven samples, shallow waters and groundwaters, for U and Ra, furthermore were determined the values of isotopic ratio for sample of typical rocks of the area. The results of this study allow to identify: a recharge area in a restricted sector of the Meso-Cenozoic carbonates a longer and more effective water/rock interaction in the Quaternary series. U and Ra recoil models allow to estimate a groundwater residence time of about 350 years and a total water volume whose value (64*106 m3 agrees with the limited extension of the aquifer. The extension of the aquifer was constrained by comparing Sr isotopic composition of waters and local geological formations. Groundwaters seem mainly to circulate in clayey sandy Quaternary series characterized by low redox conditions.
International Nuclear Information System (INIS)
Rodriguez-Arevalo, J.; Diaz-Teijeiro, M.F.; Castano, S.
2011-01-01
A simple multiple regression model based on two geographic factors (latitude and elevation) has been developed that reproduces reasonably well the spatial distribution of the current mean oxygen-18 isotope composition in precipitation over Spain. In a preliminary analysis, additional geographic and climatic factors do not improve the performance of the model. A continuous digital map of oxygen-18 isotope composition in precipitation has been produced by combining the polynomial model with a Digital Elevation Model using GIS tools. Application of the resulting map to several case studies in Spain has shown it to be useful as a reference of the isotope input function to groundwater recharge and surface runoff. The results obtained so far show a good fit between modelled stable isotope values and those measured in surface and ground waters from different aquifers and recharge areas. The GIS tools applied to a continuous digital layer of spatial isotope are able to provide accurate information at detailed scales that are not affordable by other means. Further validation of the model, and further testing of its usefulness in surface hydrology and climatic studies, is going on.
Rechargeable batteries applications handbook
1998-01-01
Represents the first widely available compendium of the information needed by those design professionals responsible for using rechargeable batteries. This handbook introduces the most common forms of rechargeable batteries, including their history, the basic chemistry that governs their operation, and common design approaches. The introduction also exposes reader to common battery design terms and concepts.Two sections of the handbook provide performance information on two principal types of rechargeable batteries commonly found in consumer and industrial products: sealed nickel-cad
Geophysical Methods for Investigating Ground-Water Recharge
Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.
2007-01-01
While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods
Summary of groundwater-recharge estimates for Pennsylvania
Stuart O. Reese,; Risser, Dennis W.
2010-01-01
Groundwater recharge is water that infiltrates through the subsurface to the zone of saturation beneath the water table. Because recharge is a difficult parameter to quantify, it is typically estimated from measurements of other parameters like streamflow and precipitation. This report provides a general overview of processes affecting recharge in Pennsylvania and presents estimates of recharge rates from studies at various scales.The most common method for estimating recharge in Pennsylvania has been to estimate base flow from measurements of streamflow and assume that base flow (expressed in inches over the basin) approximates recharge. Statewide estimates of mean annual groundwater recharge were developed by relating base flow to basin characteristics of HUC10 watersheds (a fifth-level classification that uses 10 digits to define unique hydrologic units) using a regression equation. The regression analysis indicated that mean annual precipitation, average daily maximum temperature, percent of sand in soil, percent of carbonate rock in the watershed, and average stream-channel slope were significant factors in the explaining the variability of groundwater recharge across the Commonwealth.Several maps are included in this report to illustrate the principal factors affecting recharge and provide additional information about the spatial distribution of recharge in Pennsylvania. The maps portray the patterns of precipitation, temperature, prevailing winds across Pennsylvania’s varied physiography; illustrate the error associated with recharge estimates; and show the spatial variability of recharge as a percent of precipitation. National, statewide, regional, and local values of recharge, based on numerous studies, are compiled to allow comparison of estimates from various sources. Together these plates provide a synopsis of groundwater-recharge estimations and factors in Pennsylvania.Areas that receive the most recharge are typically those that get the most
He, Xin; Song, Xiyun; Frey, Eric C.
2008-01-01
The diagnosis of cardiac disease using dual-isotope myocardial perfusion SPECT (MPS) is based on the defect status in both stress and rest images, and can be modeled as a three-class task of classifying patients as having no, reversible, or fixed perfusion defects. Simultaneous acquisition protocols for dual-isotope MPS imaging have gained much interest due to their advantages including perfect registration of the 201Tl and 99mTc images in space and time, increased patient comfort, and higher...
Geochemical and flow modelling as tools in monitoring managed aquifer recharge
International Nuclear Information System (INIS)
Niinikoski, Paula; Saraperä, Sami; Hendriksson, Nina; Karhu, Juha A.
2016-01-01
Due to a growing world population and the effects of anthropogenic climate change, access to clean water is a growing global concern. Managed aquifer recharge (MAR) is a method that can help society's response to this increasing demand for pure water. In MAR, the groundwater resources are replenished and the quality of the recharged surface water is improved through effects such as the removal of organic matter. This removal occurs through mechanisms such as microbial decomposition, which can be monitored by studying the isotopic composition of dissolved inorganic carbon (DIC). Nevertheless, the monitoring can be difficult when there are other factors, like dissolving calcite, affecting the isotopic composition of DIC. The aims of this study were to establish a method for monitoring the decomposition of organic matter (dissolved organic carbon – DOC) in cases where calcite dissolution adds another component to the DIC pool, and to use this method to monitor the beginning and amount of DOC decomposition on a MAR site at Virttaankangas, southwestern Finland. To achieve this, we calculated the mean residence times of infiltrated water in the aquifer and the fractions of this water reaching observation wells. We conducted geochemical modelling, using PHREEQC, to estimate the amount of DOC decomposition and the mineral reactions affecting the quality of the water. - Highlights: • The decomposition of DOC in MAR systems is residence time dependent. • High pH environment can delay the beginning of the decomposition process. • Shortest travel times do not correlate with mean residence times in MAR systems.
Solution of tasks concerning protection of underground waters and environment
International Nuclear Information System (INIS)
Dubinchuk, V.T.; Polyakov, V.A.
1988-01-01
Use of environment isotopes and indicators in solving problems concerning protection of underground waters and environment is discussed. The applied methods permit to study dynamics of underground waters and to estimate risk of their contamination; to follow the surface and underground waters interrelations using data on infiltration recharge estimation etc. Complex nuclear-geophysical and isotope studies may be applied to detect hindered water exchange zones where liquid industrial waste disposals could be placed with minimum damage to environment. 48 refs.; 74 figs.; 22 tabs
Appraisal of groundwater resources of Ziarat valley using isotopic techniques
International Nuclear Information System (INIS)
Ahmad, M.; Akram, W.; Tasneem, M.A.; Rafique, M.
2009-07-01
Study of water resources of Ziarat Valley was carried out to investigate groundwater recharge mechanism and effectiveness of delay action dams. Samples of precipitation (rain, snow), dam reservoirs and groundwater (dug wells, tube wells, karezes, springs) were periodically collected from different locations and analyzed for environmental isotopes (/sup 2/H, /sup 3/H, /sup 18/O, /sup 34/S). The data indicate that rainfall and snow samples show wide ranges of delta /sup 2/H and delta /sup 18/O. However, the mean values for these isotopes are -6.4% and -37% respectively. Mean tritium value of rain is 9TU. Delta /sup 2/H and delta /sup 18/O values of dam reservoirs range from -6.7 to +4.9% and -42 to +30% respectively. Average isotopic indices of all the karezes are close to each other. Mean delta /sup 18/O and delta /sup 2/H values of Sandaman Tangi, Faran Tangi and Quaid springs vary from -6.3 to -6% and -40 to -31%. Tritium concentration of Sandaman Tangi and Faran Tangi springs (7 TU) is less than Quaid spring (11TU). Ranges of mean delta /sup 18/O and delta /sup 2/H values of all the groundwater samples (wells, karezes, springs) are -6.6 to -2.2% and -40 to -16% respectively. Delta /sup 34/S values of dissolved sulphates in groundwater vary from -8.5 to -0.8%. In /sup 18/O vs. /sup 2/H plot, most of the groundwater samples lie close to LMWL indicating the meteoric origin. Reservoir water in Pechi Dam shows highly enriched isotopic values in summer due to evaporation. Such enriched values are not depicted by the groundwater in the wells and karezes downstream of the dam. This implies that there is no significant recharge from this dam. Similar is the case of Mana Dam. Vouch Ghouski Dam has some contribution towards groundwater recharge while Warchoom Dam is much effective and makes significant contribution. Results of tritium dating suggest that residence time of groundwater is quite short (only few years). (author)
Geochemical Processes During Managed Aquifer Recharge With Desalinated Seawater
Ganot, Y.; Holtzman, R.; Weisbrod, N.; Russak, A.; Katz, Y.; Kurtzman, D.
2018-02-01
We study geochemical processes along the variably-saturated zone during managed aquifer recharge (MAR) with reverse-osmosis desalinated seawater (DSW). The DSW, post-treated at the desalination plant by calcite dissolution (remineralization) to meet the Israeli water quality standards, is recharged into the Israeli Coastal Aquifer through an infiltration pond. Water quality monitoring during two MAR events using suction cups and wells inside the pond indicates that cation exchange is the dominant subsurface reaction, driven by the high Ca2+ concentration in the post-treated DSW. Stable isotope analysis shows that the shallow groundwater composition is similar to the recharged DSW, except for enrichment of Mg2+, Na+, Ca2+, and HCO3-. A calibrated variably-saturated reactive transport model is used to predict the geochemical evolution during 50 years of MAR for two water quality scenarios: (i) post-treated DSW (current practice) and (ii) soft DSW (lacking the remineralization post-treatment process). The latter scenario was aimed to test soil-aquifer-treatment (SAT) as an alternative post-treatment technique. Both scenarios provide an enrichment of ˜2.5 mg L-1 in Mg2+ due to cation exchange, compared to practically zero Mg2+ currently found in the Israeli DSW. Simulations of the alternative SAT scenario provide Ca2+ and HCO3- remineralization due to calcite dissolution at levels that meet the Israeli standard for DSW. The simulated calcite content reduction in the sediments below the infiltration pond after 50 years of MAR was low (<1%). Our findings suggest that remineralization using SAT for DSW is a potentially sustainable practice at MAR sites overlying calcareous sandy aquifers.
Directory of Open Access Journals (Sweden)
Spannenberg Jescica
2017-09-01
Full Text Available Fractional differentiation has adequate use for investigating real world scenarios related to geological formations associated with elasticity, heterogeneity, viscoelasticity, and the memory effect. Since groundwater systems exist in these geological formations, modelling groundwater recharge as a real world scenario is a challenging task to do because existing recharge estimation methods are governed by linear equations which make use of constant field parameters. This is inadequate because in reality these parameters are a function of both space and time. This study therefore concentrates on modifying the recharge equation governing the EARTH model, by application of the Eton approach. Accordingly, this paper presents a modified equation which is non-linear, and accounts for parameters in a way that it is a function of both space and time. To be more specific, herein, recharge and drainage resistance which are parameters within the equation, became a function of both space and time. Additionally, the study entailed solving the non-linear equation using an iterative method as well as numerical solutions by means of the Crank-Nicolson scheme. The numerical solutions were used alongside the Riemann-Liouville, Caputo-Fabrizio, and Atangana-Baleanu derivatives, so that account was taken for elasticity, heterogeneity, viscoelasticity, and the memory effect. In essence, this paper presents a more adequate model for recharge estimation.
Isotopic evolution of aqueous sulphate in northern Chile water
International Nuclear Information System (INIS)
Aravena, R.; Suzuki, O.; Fritz, P.; Pena, H.; Rauert, W.
1987-01-01
Full text: The extremely arid condition of northern Chile is the main obstacle to the present and future development of urban centres and economic activities in the region. The existing water resources are scarce. During the last decade, isotope techniques have been applied to investigate aspects such as the origin and residence time of the groundwater, these being extremely important for water development and water management. This paper presents 18 O and 34 S data in aqueous sulphate, as well as 18 O, 2 H, and 3 H from springs, rivers and groundwater samples of the Pampa del Tamarugal and Salar de Llamara basins. The principal aim of this study was to investigate the isotope evolution of the sulphate, the origin of the sulphur, the groundwater flow path, and the possibility of using the 18 O of the sulphate as a tracer for estimation of the residence time of the groundwater. Springs that have their recharge area in the high Altiplano (Salar del Huasco basin) show δ values between +5.0 per mille and +6.0 per mille for the 18 O and +5.0 per mille and +9.0 per mille for the 34 S isotope. Springs from lower altitude, show an isotope content between + 8.6 per mille and + 10.6 per mille for 18 O and +7.4 per mille and + 11.7 per mille for 34 S. The groundwaters in the Pampa aquifers, based on their hydrogen and oxygen isotope composition, are associated with different recharge areas. However, these waters show an isotope range for the sulphate similar to .he one of the springs, and no clear relationships are observed between isotope content, flow path and residence time. This pattern could be related to the poorly defined aquifer systems present in the Pampa. The Llamara groundwaters have a uniform isotope content and are the most enriched in the region (δ 18 O = -6.0 per mille and δ 2 H = -50 per mille). The isotope composition of their sulphate compares well with the Pampa groundwater, indicating a similar sulphate source. The isotope composition of gypsum
Golan Heights Groundwater Systems: Separation By REE+Y And Stable Isotopes
Siebert, C.; Geyer, S.; Knoeller, K.; Roediger, T.; Weise, S.; Dulski, P.; Moeller, P.; Guttman, J.
2008-12-01
In a semi-arid to arid country like Israel, all freshwater resources are under (over-) utilization. Particularly, the Golan Heights rank as one of the most important extraction areas of groundwater of good quality and quantity. Additionally the mountain range feed to a high degree the most important freshwater reservoir of Israel, the Sea of Galilee. Hence, knowing the sources and characters of the Golan Heights groundwater systems is an instantaneous demand regarding sustainable management and protection. Within the "German-Israeli-Jordanian-Palestinian Joint Research Program for the Sustainable Utilisation of Aquifer Systems", hundreds of water samples were taken from all over the Jordan-Dead Sea rift-system to understand groundwater flow-systems and salinisation. For that purpose, each sample was analysed for major and minor ions, rare earth elements including yttrium (REY) and stable isotopes of water (d18O, d2H). The REY distribution in groundwater is established during infiltration by the first water-rock interaction and consequently reflects the leachable components of sediments and rocks of the recharge area. In well- developed flow-systems, REY are adsorbed onto pore surfaces are in equilibrium with the percolating groundwater, even if the lithology changes (e.g. inter-aquifer flow). Thus, groundwater sampled from wells and springs still show the REY distribution pattern established in the recharge area. Since high temperatures do not occur in Golan Heights, d2H and d18O are less controlled by water-rock interaction than by climatic and geomorphological factors at the time of replenishment. Applying the REY signature as a grouping criterion of groundwaters, d18O vs. d2H plots yield a new dimension in interpreting isotope data. The combined use of hydrochemical and isotopic methods enabled us to contain the areas of replenishment and the flow-paths of all investigated groundwater in the Golan Heights. Despite location, salinity or temperature of spring or
Progress in aqueous rechargeable batteries
Directory of Open Access Journals (Sweden)
Jilei Liu
2018-01-01
Full Text Available Over the past decades, a series of aqueous rechargeable batteries (ARBs were explored, investigated and demonstrated. Among them, aqueous rechargeable alkali-metal ion (Li+, Na+, K+ batteries, aqueous rechargeable-metal ion (Zn2+, Mg2+, Ca2+, Al3+ batteries and aqueous rechargeable hybrid batteries are standing out due to peculiar properties. In this review, we focus on the fundamental basics of these batteries, and discuss the scientific and/or technological achievements and challenges. By critically reviewing state-of-the-art technologies and the most promising results so far, we aim to analyze the benefits of ARBs and the critical issues to be addressed, and to promote better development of ARBs.
International Nuclear Information System (INIS)
Aly, A.I.M.; Nada, A.; Awad, M.; Salman, A.B.; Hamza, M.S.
1991-01-01
Groundwater samples collected from some localities in the vicinity of Moghra and Ain El-Sharip in the north western desert were subjected to chemical and to isotopic analyses. The combination of the hydrochemical data with the isotopic compositions of deuterium, oxygen-18 and tritium shows that the groundwater in this region represents a mixture of water recharged from different sources including : Nile, sea and paleo-waters.5 fig.,2 tab
International Nuclear Information System (INIS)
Duke, L.L.
1989-09-01
To comply with Department of Energy Order 5480.XX (Draft), a job/task analysis was initiated by the Maintenance Management Department at Oak Ridge National Laboratory (ORNL). The analysis was applicable to instrument technicians working at the ORNL High Flux Isotope Reactor (HFIR). This document presents the procedures and results of that analysis. 2 refs., 2 figs
International Nuclear Information System (INIS)
Edmunds, W.M.
2001-01-01
Isotopic techniques combined with chemistry can provide comprehensive information on groundwater recharge and recharge history, as well as on environmental and climatic change. Examples of integrated use are reviewed from studies in Senegal and Cyprus as well as Sudan. Tritium provides calibration for the wider use of Cl as a tool for larger scale recharge estimation in low rainfall areas. A recharge history is preserved in the unsaturated zone in favourable locations where homogeneous unsaturated flow predominates. Recharge variations taking place at the decadal scale tie in well with instrumental records and extrapolation indicates records may exist over centuries or millennia. Results from the CRP, from Nigeria, Tunisia, Jordan and Mexico have been modelled against local rainfall records and chemistry to give a reasonable correlation with recharge events over various timescales from 30 to 50 000 yr. (author)
Gastmans, Didier; Chang, Hung Kiang; Hutcheon, Ian
2010-09-01
The groundwater flow pattern of the western part of the Guarani Aquifer System (GAS), Brazil, is characterized by three regional recharge areas in the north, and a potentiometric divide in the south, which trends north-south approximately. Groundwater flow is radial from these regional recharge areas toward the center of Paraná Sedimentary Basin and toward the western outcrop areas at the border of the Pantanal Matogrossense, because of the potentiometric divide. The isotopic composition of GAS groundwater leads to understanding the paleoclimatic conditions in the regional recharge areas. The δ18O and δ2H isotopic ratios of GAS groundwaters vary, respectively, from -9.1 to -4.8‰ V-SMOW and -58.4 to -21.7‰ V-SMOW. In the recharge zones, enriched δ18O values are observed, while in the confined zone lighter δ18O values are observed. These suggest that climatic conditions were 10°C cooler than the present during the recharge of these waters. The δ13C ratios in groundwater of GAS, in the study area, vary from -19.5 to -6.5‰ VPDB, increasing along the regional flow lines toward the confined zone. This variation is related to dissolution of carbonate cement in the sandstones.
International Nuclear Information System (INIS)
Senguji, F.H.
1999-01-01
Makutupora groundwater basin has been the main source of water supply for Dodoma town since 1950s. the water is mainly used for domestic water supply to over one million inhabitants, for industrial purposes and livestock watering. Conventional hydrogeological investigations have been carried out in the basin to gather information on the groundwater potential of the basin to meet the ever-increasing demand for water. However, firm conclusions could not be reached with conventional methods. This paper highlights on the isotope techniques applied in an integrated manner with conventional hydrogeological methods to study the groundwater regime of the Makutupora basin. Results of isotope techniques have provided adequate information on recharge locations, recharge rates and age of groundwater in the basin, that is very important and open up prospects for further investigations using isotope techniques. The ongoing investigation in the basin regarding pollution and depletion of the groundwater resource, has not succeeded in defining specific pumping limits or groundwater protection zones. Isotope data are sought to provide a clear basis for regulatory and future groundwater management in the Makutupora basin. (author)
Energy Technology Data Exchange (ETDEWEB)
Palacio, P.; Dapena, C.; Betancur, T. [Universidad de Antioquia, Medellin (Colombia)
2013-07-15
The Man River basin is located in the lower foothills of the western and central ranges of the tropical Andes, Colombia. In this area hydrological studies and hydrochemical analyses were carried out and isotopic techniques applied to describe and understand the interactions between ground and surface waters. To expand this model and to include elements other than local hydrodynamics, relationships between regional precipitation, recharge, regional flow paths and hydraulic gradients controlling water flows from big rivers to groundwater are currently being explored. Accordingly, an isotope local meteoric water line was derived and it was discovered that the relationship between ground and surface waters is similar in wet and dry seasons. Precipitation constitutes the main recharge source, base flow is important in supporting flow in rivers, streams and wetlands, and evaporation causes effects over water systems in dry periods. A tendency towards increasing air temperatures has been detected in the Man River; this change may cause negative impacts over the hydrological system, affecting evapotranspiration- recharge processes. (author)
A study plan for determining recharge rates at the Hanford Site using environmental tracers
International Nuclear Information System (INIS)
Murphy, E.M.; Szercsody, J.E.; Phillips, S.J.
1991-02-01
This report presents a study plan for estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, 36 Cl, 3 H, and 2 H/ 18 O. Atmospheric levels of 36 Cl and 3 H increased during nuclear bomb testing in the Pacific, and the resulting ''bomb pulse'' or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resulted in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, 129 I, and 99 Tc. Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Six tracer techniques (total chloride, 36 Cl, 3 H, nitrate, 129 I, and 99 Tc) will be tested on at least one site in the Quincy sand, one site in the Warden silt loam, and the background site, to determine which combination of tracers works best for a given soil type. In subsequent years, additional sites will be investigated. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial variability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other arid sites. 166 refs., 41 figs., 16 tabs
Application of Isotope techniques in the arid and semi-arid zone hydrology
International Nuclear Information System (INIS)
Gonfiantini, R.; Louvat, D.; Aranyossy, J.F.
1993-01-01
The paper presents a brief introduction on the scientific background of isotope hydrology,and after, explains the applications of environment isotope techniques in groundwater hydrology of the arid and semi-arid zones. It includes the study of aquifer recharge and discharge, identification of palaeorecharge, groundwater movement and age in unconfined and confined aquifers, and interconnections between aquifers. The contribution of isotopes is highlighted with many examples of field case studies, with emphasis on studies carried out with IAEA support. Finally, a short description of IAEA program on isotope hydrology is given, with a list of regional projects supported through the IAEA Technical Cooperation program, and of Coordinated Research Programs. The latter give the modern research trends in isotope application to hydrology and hydrosphere environmental studies. (author). 2 tabs., 25 figs., 69 refs
Hydrological processes in the subsurface investigated by water isotopes and silica
Czech Academy of Sciences Publication Activity Database
Šanda, M.; Kulasová, Alena; Císlerová, M.
2009-01-01
Roč. 4, Sp. is. 2 (2009), S83-S92 ISSN 1801-5395 R&D Projects: GA ČR GA205/06/0375 Institutional research plan: CEZ:AV0Z20600510 Keywords : rainfall to runoff response * isotopes * geochemical tracers * streamflow generation * subsurface stormflow * groundwater recharge Subject RIV: DA - Hydrology ; Limnology
Isotope characterization of shallow aquifers in the Horombe region, South of Madagascar
International Nuclear Information System (INIS)
Fareze, L.P.; Rajaobelison, J.; Ramaroson, V.; Raoelina Andriambololona; Andriamiarintsoa, G.; Razafitsalama, P.R.; Rahobisoa, J.J.; Randrianarison, H.; Ranaivoarisoa, A.; Marah, H.
2011-01-01
The present study deals with the problem of evaluation of the recharge mechanism and the characterization of the groundwater flow system in the basement shallow aquifer, which is one of the groundwater resource in the semi-arid South region of Madagascar. Stable isotopes (deuterium and oxygen-18) and tritium are used to achieve with accuracy the hydrogeological and geochemical dynamics study. Chemical analysis is used to provide complementary information to the investigation. A space distribution of tritium concentration and isotopic composition in groundwater shows evidence of two opposite categories of aquifers, which is confirmed by the chemical analysis results and by the geological features of the study site. Some groundwater flow path directions have been identified in the study area thanks to the tritium concentration space distribution and the geological formation. Besides, the groundwater recharge of the shallow aquifers in the South of Madagascar has been characterized by the exponential mixing model.
Environmental isotope study of a groundwater supply project in the Kalahari of Gordonia
International Nuclear Information System (INIS)
Verhagen, B.T.
1984-01-01
A feasibility study for a central fresh groundwater supply scheme in the Kalahari of the Gordonia district, South Africa, provided the opportunity to study fresh and saline water occurrences in detail with environmental isotopes. The isotopic and chemical signals show a clear contrast among groundwaters below a river bed, an extended fresh groundwater body and saline groundwaters in close proximity to the river. Carbon-14, tritium and stable-isotope data lead to a vertical rain recharge model rather than a regional flow mechanism for an understanding of the various water occurrences, their interrelationships and varied hydrochemistry. (author)
Recharge at the Hanford Site: Status report
International Nuclear Information System (INIS)
Gee, G.W.
1987-11-01
A variety of field programs designed to evaluate recharge and other water balance components including precipitation, infiltration, evaporation, and water storage changes, have been carried out at the Hanford Site since 1970. Data from these programs have indicated that a wide range of recharge rates can occur depending upon specific site conditions. Present evidence suggests that minimum recharge occurs where soils are fine-textured and surfaces are vegetated with deep-rooted plants. Maximum recharge occurs where coarse soils or gravels exist at the surface and soils are kept bare. Recharge can occur in areas where shallow-rooted plants dominate the surface, particularly where soils are coarse-textured. Recharge estimates have been made for the site using simulation models. A US Geological Survey model that attempts to account for climate variability, soil storage parameters, and plant factors has calculated recharge values ranging from near zero to an average of about 1 cm/yr for the Hanford Site. UNSAT-H, a deterministic model developed for the site, appears to be the best code available for estimating recharge on a site-specific basis. Appendix I contains precipitation data from January 1979 to June 1987. 42 refs., 11 figs., 11 tabs
Statewide Groundwater Recharge Modeling in New Mexico
Xu, F.; Cadol, D.; Newton, B. T.; Phillips, F. M.
2017-12-01
It is crucial to understand the rate and distribution of groundwater recharge in New Mexico because it not only largely defines a limit for water availability in this semi-arid state, but also is the least understood aspect of the state's water budget. With the goal of estimating groundwater recharge statewide, we are developing the Evapotranspiration and Recharge Model (ETRM), which uses existing spatial datasets to model the daily soil water balance over the state at a resolution of 250 m cell. The input datasets includes PRISM precipitation data, MODIS Normalized Difference Vegetation Index (NDVI), NRCS soils data, state geology data and reference ET estimates produced by Gridded Atmospheric Data downscalinG and Evapotranspiration Tools (GADGET). The current estimated recharge presents diffuse recharge only, not focused recharge as in channels or playas. Direct recharge measurements are challenging and rare, therefore we estimate diffuse recharge using a water balance approach. The ETRM simulated runoff amount was compared with USGS gauged discharge in four selected ephemeral channels: Mogollon Creek, Zuni River, the Rio Puerco above Bernardo, and the Rio Puerco above Arroyo Chico. Result showed that focused recharge is important, and basin characteristics can be linked with watershed hydrological response. As the sparse instruments in NM provide limited help in improving estimation of focused recharge by linking basin characteristics, the Walnut Gulch Experimental Watershed, which is one of the most densely gauged and monitored semiarid rangeland watershed for hydrology research purpose, is now being modeled with ETRM. Higher spatial resolution of field data is expected to enable detailed comparison of model recharge results with measured transmission losses in ephemeral channels. The final ETRM product will establish an algorithm to estimate the groundwater recharge as a water budget component of the entire state of New Mexico. Reference ET estimated by GADGET
Application of 18O and 2H natural isotopes for groundwater study in Semarang Basin, Central Java
International Nuclear Information System (INIS)
Rasi Prasetio; Satrio
2015-01-01
As a big city that support industrialism, Semarang has increasing needs of fresh water supply which is mostly provided by ground water. The utilization of groundwater must consider sustainability and environmental preservation aspects, as water is basic needs for human being. Therefore, the knowledge about groundwater dynamics is important to manage groundwater utilization. Isotope hydrology technique using 18 O and 2 H isotopes has been applied to investigate groundwater dynamics and can be taken as consideration for groundwater management. For this purpose, water samples have been collected from various water sources such as springs, deep monitoring wells, dug wells, streams and rain water for 18 O and 2 H isotopes analysis. The results show that isotopes composition of groundwater varied between -8.77‰ to -4.76‰ for δ 18 O and -56.6‰ to -29.4‰ for δ 2 H. Isotopes composition for unconfined groundwater in most of study area are relatively uniform, i.e. between -5.9‰ to -6.6‰ for δ 18 O and -35.1‰ to -40.4‰ for δ 2 H, except in some minor places that have more depleted and more enriched composition. This distribution indicates that the unconfined aquifer is depend on local recharge. While most of isotopes composition of deep confined aquifer plotted around isotopes composition of Ungaran's rain water, indicates that the recharge area of these confined groundwater were originated from this elevation or higher. (author)
Clark, Jordan F; Hudson, G Bryant; Avisar, Dror
2005-06-01
A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.
Ganot, Yonatan; Holtzman, Ran; Weisbrod, Noam; Nitzan, Ido; Katz, Yoram; Kurtzman, Daniel
2017-09-01
We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors, and observation wells. During a month (January 2015) of continuous intensive MAR (2.45 × 106 m3 discharged to a 10.7 ha area), groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from ˜ 11 to ˜ 0.4 m d-1). This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments. Clogging processes at the pond-surface - abundant in many MAR operations - are negated by the high-quality desalinated seawater (turbidity ˜ 0.2 NTU, total dissolved solids ˜ 120 mg L-1) or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016) fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models.
International Nuclear Information System (INIS)
Kebede, Seifu; Travi, Yves; Alemayehu, Tamiru; Ayenew, Tenalem
2005-01-01
Geochemical and environmental isotope data were used to gain the first regional picture of groundwater recharge, circulation and its hydrochemical evolution in the upper Blue Nile River basin of Ethiopia. Q-mode statistical cluster analysis (HCA) was used to classify water into objective groups and to conduct inverse geochemical modeling among the groups. Two major structurally deformed regions with distinct groundwater circulation and evolution history were identified. These are the Lake Tana Graben (LTG) and the Yerer Tullu Wellel Volcanic Lineament Zone (YTVL). Silicate hydrolysis accompanied by CO 2 influx from deeper sources plays a major role in groundwater chemical evolution of the high TDS Na-HCO 3 type thermal groundwaters of these two regions. In the basaltic plateau outside these two zones, groundwater recharge takes place rapidly through fractured basalts, groundwater flow paths are short and they are characterized by low TDS and are Ca-Mg-HCO 3 type waters. Despite the high altitude (mean altitude ∼2500 masl) and the relatively low mean annual air temperature (18 deg. C) of the region compared to Sahelian Africa, there is no commensurate depletion in δ 18 O compositions of groundwaters of the Ethiopian Plateau. Generally the highland areas north and east of the basin are characterized by relatively depleted δ 18 O groundwaters. Altitudinal depletion of δ 18 O is 0.1%o/100 m. The meteoric waters of the Blue Nile River basin have higher d-excess compared to the meteoric waters of the Ethiopian Rift and that of its White Nile sister basin which emerges from the equatorial lakes region. The geochemically evolved groundwaters of the YTVL and LTG are relatively isotopically depleted when compared to the present day meteoric waters reflecting recharge under colder climate and their high altitude
Energy Technology Data Exchange (ETDEWEB)
Kebede, Seifu [Laboratory of Hydrogeology, University of Avignon, 33 Rue Louis Pasteur, 84000 Avignon (France) and Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)]. E-mail: seifu.kebede@univ-avignon.fr; Travi, Yves [Laboratory of Hydrogeology, University of Avignon, 33 Rue Louis Pasteur, 84000 Avignon (France); Alemayehu, Tamiru [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia); Ayenew, Tenalem [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)
2005-09-15
Geochemical and environmental isotope data were used to gain the first regional picture of groundwater recharge, circulation and its hydrochemical evolution in the upper Blue Nile River basin of Ethiopia. Q-mode statistical cluster analysis (HCA) was used to classify water into objective groups and to conduct inverse geochemical modeling among the groups. Two major structurally deformed regions with distinct groundwater circulation and evolution history were identified. These are the Lake Tana Graben (LTG) and the Yerer Tullu Wellel Volcanic Lineament Zone (YTVL). Silicate hydrolysis accompanied by CO{sub 2} influx from deeper sources plays a major role in groundwater chemical evolution of the high TDS Na-HCO {sub 3} type thermal groundwaters of these two regions. In the basaltic plateau outside these two zones, groundwater recharge takes place rapidly through fractured basalts, groundwater flow paths are short and they are characterized by low TDS and are Ca-Mg-HCO {sub 3} type waters. Despite the high altitude (mean altitude {approx}2500 masl) and the relatively low mean annual air temperature (18 deg. C) of the region compared to Sahelian Africa, there is no commensurate depletion in {delta} {sup 18}O compositions of groundwaters of the Ethiopian Plateau. Generally the highland areas north and east of the basin are characterized by relatively depleted {delta} {sup 18}O groundwaters. Altitudinal depletion of {delta} {sup 18}O is 0.1%o/100 m. The meteoric waters of the Blue Nile River basin have higher d-excess compared to the meteoric waters of the Ethiopian Rift and that of its White Nile sister basin which emerges from the equatorial lakes region. The geochemically evolved groundwaters of the YTVL and LTG are relatively isotopically depleted when compared to the present day meteoric waters reflecting recharge under colder climate and their high altitude.
Climatic controls on diffuse groundwater recharge across Australia
Directory of Open Access Journals (Sweden)
O. V. Barron
2012-12-01
Full Text Available Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, the correlation between the modelled recharge and total annual rainfall is weaker than the correlation between recharge and the annual rainfall parameters reflecting rainfall intensity. Under similar soil and vegetation conditions for the same annual rainfall, annual recharge in regions with winter-dominated rainfall is greater than in regions with summer-dominated rainfall. The importance of climate parameters other than rainfall in recharge estimation is highest in the tropical climate type. Mean annual values of solar radiation and vapour pressure deficit show a greater importance in recharge estimation than mean annual values of the daily mean temperature. Climate parameters have the lowest relative importance in recharge estimation in the arid climate type (with cold winters and the temperate climate type. For 75% of all soil, vegetation and climate types investigated, recharge elasticity varies between 2 and 4 indicating a 20% to 40% change in recharge for a 10% change in annual rainfall. Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.
Petelet-Giraud, Emmanuelle; Cary, Lise; Bertrand, Guillaume; Hirata, Ricardo; Martins, Veridiana; Montenegro, Suzana; Pauwels, Hélène; Kloppmann, Wolfram; Aquilina, Luc
2014-05-01
The Metropolitan Region of Recife (RMR) went through large changes of water and land uses over the last decades due to an increasing demographic pressure (1.5 M of inhabitants). These evolutions gave rise to numerous environmental consequences, such as a dramatic decline of the water levels, groundwater salinization and contamination. This degradation of natural resources is linked to the increase of water demand that is also punctually amplified by drought periods, inducing the construction of thousands of private wells. Recife city was built on an estuarine area, at the geological limits of the two sedimentary basins of Pernambuco (north of the city) and Paraíba (south of the city) separated by a famous shear zone (the Pernambuco lineament). Tectonic and sedimentary events involved in the genesis and evolution of these basins were mainly controlled by the opening of the Atlantic Ocean leading to the deposition of cretaceous sediments which now constitute the two main exploited aquifers, the Beberibe and Cabo aquifers. These two deep aquiferous formations are topped by the unconfined Boa Viagem aquifer of quaternary sediments. It is the most directly exposed to contamination, since it is connected to mangroves, rivers, estuaries and highly urbanized areas. Both the Beberibe and Cabo aquifers contain large clay levels and are separated by a rather continuous clayed formation which seems to play a consistent role of screen and to interfere in the hydraulic connections between the three aquifers. Previous isotopic studies have shown that recharge processes are similar in the aquifers, suggesting that exchanges may occur and may be modified or amplified by overexploitation. This very complex aquifer system is studied through more than 60 water samples, including some surface water samples from the main rivers. A methodology based on multi-isotopes fingerprinting is applied, including stable isotopes of the water molecule, strontium isotopes, boron isotopes, sulfur
Futuristic isotope hydrology in the Gulf region
Saravana Kumar, U.; Hadi, Khaled
2018-03-01
The Gulf region is one of the most water-stressed parts in the world. Water in the region is very scarce, shortage of supply and lacking of renewable water resources, while the demand for water is growing day by day. It is thus essential to implement modern approaches and technologies in addressing water-related issues. In this context, isotope hydrology will provide invaluable aid. Some of the most important areas of futuristic applications of isotope hydrology include evaluation of aquifer recharge, storage and their recovery system, understanding of dynamic changes due to long-term exploitation of the groundwater, development and management of shared groundwater aquifers, fresh groundwater discharge along the Arabian Gulf, identification and quantification of hydrocarbon contamination in groundwater; soil moisture and solute movement in unsaturated zone, paleoclimate reconstruction, etc. Literature survey suggests, in general, not many isotope studies on the above have been reported.
Isotopic and chemical investigations of quaternary aquifer in sinai peninsula
International Nuclear Information System (INIS)
Sadek, M.A.; Ahmed, M.A.; Awad, M.A.
2001-01-01
The present study has been conducted to investigate the renewal activity and mineralization potential of the quaternary aquifer in Sinai peninsula using environmental isotopes and hydrochemistry. The quaternary aquifer is vital for development processes as it has a wide extension and shallow water table. The total dissolved salts vary greatly from one location to another and range widely between 510-7060 mg/1, reflecting all categories from fresh to saline water. The change in salinity all over Sinai can be attributed to variations in the rate of evaporation. Leaching and dissolution of terrestrial salts during floods as well as the effects of sea spray and saline water intrusion. The main sources of groundwater recharge are the infiltration of Local precipitation and surface runoff as well as lateral flow through hydraulic connection with fractured aquifers. Snow melt also contributes to aquifer recharge in some areas in the central part of southern Sinai. The environmental stable isotopic contents of the ground water in the quaternary aquifer in Sinai reflect the isotopic composition of rain water from continental and east Mediterranean precipitation and monsonal air mass which comes from Indian ocean as well as the seepage of partly evaporated floodwater. The southern samples are more suitable for drinking and irrigation purposes due to its lower salinity and sodium hazard
The A.B.Cs of isotope hydrology
International Nuclear Information System (INIS)
Maduabuchi, C.
2000-01-01
The steady growth in world population coupled with the extension of irrigated agriculture and accelerated industrial development and other economic activities have put tremendous stress on the quantity and quality aspects of surface and groundwater resources the world over. The situation calls for necessary monitoring mechanism to safeguard these renewable but potentially depletable resources. A proper understanding of water resources systems is a prerequisite to their sustainable development. This informed the application of isotope techniques in hydrology as they provide vital information that are not readily obtainable from the classical hydrological techniques. These include issues relating to origin and history of groundwater, recharge estimates, vulnerability of aquifers to pollution, mixing proportion of component flows and study of geothermal systems amongst others. Maximum benefits are derived from the application of isotope techniques when they are complemented with conventional techniques in an integrated manner. The paper discusses the basic concepts which include configuration of the nucleus of the atom, isotopes, radioactivity and radioactive decay law. It further explains the occurrence of environmental isotopes including their measurement in natural compounds and the general application of isotopes in water resources development and management
Interpretation of groundwater origin in the Velenje coal mine on the basis of isotope composition
Directory of Open Access Journals (Sweden)
Janko Urbanc
2002-12-01
Full Text Available The aim of the investigation was to determine the isotopic properties of cave waters from the Velenje coal mine and define the recharge areas of individual aquifers. With regard to the oxygen isotope composition, groundwater in the Velenje coal mine can beclassified into three types. Typical d18O values of the first type are around -9 ‰ and are found in surface waters in the vicinity of the mine, therefore it is supposed that these waters are recharged locally. The second type is represented mainly by waters from thelower part of the pliocene aquifer. The average oxygen composition of these waters is about -11 ‰. This isotope composition is considerably different from the isotope composition of recent waters from the mine’s vicinity, which leads to the conclusion that these are older, fossile waters. These waters also have a very high degree of mineralization and consequently conductivity. Waters of the third type have average δ18O values around -10 ‰ and originate mainly from triassic dolomites. These waters could be a mixture of recentand old waters, but it is also possible that they flow into the coal mine from the higher areas of Paški Kozjak.
Zhang, Wenjie; Chen, Xi; Tan, Hongbing; Zhang, Yanfei; Cao, Jifu
2015-04-15
The decline of groundwater table and deterioration of water quality related to seawater have long been regarded as a crucial problem in coastal regions. In this work, a hydrogeologic investigation using combined hydrochemical and isotopic approaches was conducted in the coastal region of the South China Sea near the Leizhou peninsular to provide primary insight into seawater intrusion and groundwater circulation. Hydrochemical and isotopic data show that local groundwater is subjected to anthropogenic activities and geochemical processes, such as evaporation, water-rock interaction, and ion exchange. However, seawater intrusion driven by the over-exploitation of groundwater and insufficient recharge is the predominant factor controlling groundwater salinization. Systematic and homologic isotopic characteristics of most samples suggest that groundwater in volcanic area is locally recharged and likely caused by modern precipitation. However, very depleted stable isotopes and extremely low tritium of groundwater in some isolated aquifers imply a dominant role of palaeowater. Copyright © 2015 Elsevier Ltd. All rights reserved.
van Geldern, Robert; Kuhlemann, Joachim; Schiebel, Ralf; Taubald, Heinrich; Barth, Johannes A C
2014-06-01
The Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (δP) with values of-8.6(± 0.2) ‰ for δ(18)O and-58(± 2) ‰ for δ(2)H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of-0.17(± 0.02) ‰ per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.
Isotope hydrological evidence of geomorphological changes in North-Eastern Hungary
International Nuclear Information System (INIS)
Hertelendi, E.; Marton, L.; Miko, L.
1991-01-01
Stable isotope and radiocarbon data of groundwater stored in Quaternary aquifers in North-Eastern Hungary can not be explained by climatic changes alone. More than two hundred δD, δ 18 O and radiocarbon ages of waters from 79 wells show that the recharge are changed during the time of upper pleniglacial and late glacial. Groundwaters of the studied are can be divided into three categories, which can explain their origin. The data are consistent with geomorphological results giving isotope evidence of hydrology for a geodynamical event during the mentioned periods. (R.P.) 3 refs.; 2 figs
Assessment of Groundwater Quality in the Western Aquifers of Mauritius Using Isotope Techniques
Energy Technology Data Exchange (ETDEWEB)
Dindyal, D.; Brizmohun, R.; Fanny, J. O.Y. [National Environmental Laboratory, Reduit (Mauritius); Sacchi, E. [Dipartimento di Scienze della Terra e dell' Ambiente, Universita di Pavia (Italy)
2013-07-15
This contribution reports the results obtained in the IAEA TC project Mar/8/007, initiated in 2007. Fourteen boreholes were sampled during three sampling campaigns (rainy season, winter and summer): analyses include major ions, trace elements, stable isotopes ({delta}{sup 2}H, {delta}{sup 18}O and {delta}{sup 13}C) and a microbiological assessment (TC and E. coli). Results indicate that groundwater quality is generally good. Recharge mostly occurs in the central plateau area, but the increase in nitrates along the groundwater flow and the common presence of E. coli indicate that a minor recharge occurs all over the aquifer's extension. Infiltration is rapid and favoured by the presence of vertical fractures in the basalts. Discharge occurs at a lower altitude and is marked by a different stable isotope content and lower nitrates. In addition to validating the general groundwater circulation model, these results show that aquifers are not adequately protected against a possible input of pollutants from the surface. (author)
Scholl, Martha A.; Murphy, Sheila F.
2014-05-01
Like many mountainous areas in the tropics, watersheds in the Luquillo Mountains of eastern Puerto Rico have abundant rainfall and stream discharge and provide much of the water supply for the densely populated metropolitan areas nearby. Projected changes in regional temperature and atmospheric dynamics as a result of global warming suggest that water availability will be affected by changes in rainfall patterns. It is essential to understand the relative importance of different weather systems to water supply to determine how changes in rainfall patterns, interacting with geology and vegetation, will affect the water balance. To help determine the links between climate and water availability, stable isotope signatures of precipitation from different weather systems were established to identify those that are most important in maintaining streamflow and groundwater recharge. Precipitation stable isotope values in the Luquillo Mountains had a large range, from fog/cloud water with δ2H, δ18O values as high as +12 ‰, -0.73 ‰ to tropical storm rain with values as low as -127 ‰, -16.8 ‰. Temporal isotope values exhibit a reverse seasonality from those observed in higher latitude continental watersheds, with higher isotopic values in the winter and lower values in the summer. Despite the higher volume of convective and low-pressure system rainfall, stable isotope analyses indicated that under the current rainfall regime, frequent trade -wind orographic showers contribute much of the groundwater recharge and stream base flow. Analysis of rain events using 20 years of 15 -minute resolution data at a mountain station (643 m) showed an increasing trend in rainfall amount, in agreement with increased precipitable water in the atmosphere, but differing from climate model projections of drying in the region. The mean intensity of rain events also showed an increasing trend. The determination of recharge sources from stable isotope tracers indicates that water supply
International Nuclear Information System (INIS)
Zouari, K.; Maliki, My.A.; Moumni, L.; Aranyossy, J.F.
2001-01-01
A chemical and isotopic study of the unsaturated zone in Nefta, southwestern Tunisia was initiated to gain an improved understanding of the recharge and evaporation processes in the shallow 'Continental Terminal' (CT) sandy aquifer outcropping in the region of Nefta, which constitutes the most important water resource for agriculture and domestic uses in the region. A single 13.5-m core was extracted and subsampled from the unsaturated zone at the end of the 'rainy season' (23-24 April 1998) using a hand auger to avoid fluid contamination. Estimated recharge rates based on isotope and chemical profiles, uncertainties, and recommendations for future research are discussed. (author)
Natural vs. artificial groundwater recharge, quantification through inverse modeling
Directory of Open Access Journals (Sweden)
H. Hashemi
2013-02-01
Full Text Available Estimating the change in groundwater recharge from an introduced artificial recharge system is important in order to evaluate future water availability. This paper presents an inverse modeling approach to quantify the recharge contribution from both an ephemeral river channel and an introduced artificial recharge system based on floodwater spreading in arid Iran. The study used the MODFLOW-2000 to estimate recharge for both steady- and unsteady-state conditions. The model was calibrated and verified based on the observed hydraulic head in observation wells and model precision, uncertainty, and model sensitivity were analyzed in all modeling steps. The results showed that in a normal year without extreme events, the floodwater spreading system is the main contributor to recharge with 80% and the ephemeral river channel with 20% of total recharge in the studied area. Uncertainty analysis revealed that the river channel recharge estimation represents relatively more uncertainty in comparison to the artificial recharge zones. The model is also less sensitive to the river channel. The results show that by expanding the artificial recharge system, the recharge volume can be increased even for small flood events, while the recharge through the river channel increases only for major flood events.
International Nuclear Information System (INIS)
Chen Jiansheng; Fan Zhechao; Gu Weizu; Zhao Xia; Wang Jiyang
2003-01-01
In the paper, the sources of spring water and well water of Qilian Mountain's north side, Longshou Mountain, Badain Jaran Desert, Gurinai, Guaizi Lake, and Ejina Basin are studied by the methods of environmental isotopes and water chemistry. The groundwater of downstream areas (such as Badain Jaran Desert) is found that it is recharged by the precipitation of Qilian Mountain, and the average recharge elevation is 3300 m. Lots of naked limestones layers exist at the mountaintop of Qilian Mountain. The snow water of Qilian Mountain melts and directly infiltrates into deep layer passing through karst stratum or Big Fault in Front of the Mountain, and directly recharges into Badain Jaran Desert and its downstream areas passing through Longshou Mountain. The calcareous cementation and travertine, found in the lakes of the desert, approve that the groundwater passed the limestone layer. Confined water recharges shallow aquifer by means of leakage. The groundwater recharge volume is six hundreds millions cubic meters per year by calculating the evaporation amount, and the age of confined groundwater is 20-30 years. (authors)
Quantification of groundwater recharge in urban environments.
Tubau, Isabel; Vázquez-Suñé, Enric; Carrera, Jesús; Valhondo, Cristina; Criollo, Rotman
2017-08-15
Groundwater management in urban areas requires a detailed knowledge of the hydrogeological system as well as the adequate tools for predicting the amount of groundwater and water quality evolution. In that context, a key difference between urban and natural areas lies in recharge evaluation. A large number of studies have been published since the 1990s that evaluate recharge in urban areas, with no specific methodology. Most of these methods show that there are generally higher rates of recharge in urban settings than in natural settings. Methods such as mixing ratios or groundwater modeling can be used to better estimate the relative importance of different sources of recharge and may prove to be a good tool for total recharge evaluation. However, accurate evaluation of this input is difficult. The objective is to present a methodology to help overcome those difficulties, and which will allow us to quantify the variability in space and time of the recharge into aquifers in urban areas. Recharge calculations have been initially performed by defining and applying some analytical equations, and validation has been assessed based on groundwater flow and solute transport modeling. This methodology is applicable to complex systems by considering temporal variability of all water sources. This allows managers of urban groundwater to evaluate the relative contribution of different recharge sources at a city scale by considering quantity and quality factors. The methodology is applied to the assessment of recharge sources in the Barcelona city aquifers. Copyright © 2017 Elsevier B.V. All rights reserved.
Harlow, J.
2017-12-01
Groundwater recharge quantification is a key parameter for sustainable groundwater management. Many recharge quantification techniques have been devised, each with advantages and disadvantages. A free, GIS based recharge quantification tool - the Soil Water Balance (SWB) model - was developed by the USGS to produce fine-tuned recharge constraints in watersheds and illuminate spatial and temporal dynamics of recharge. The subject of this research is to examine SWB within a Mediterranean climate zone, focusing on the Catalina Island, California. This project relied on publicly available online resources with the exception the geospatial processing software, ArcGIS. Daily climate station precipitation and temperature data was obtained from the Desert Research Institute for the years 2008-2014. Precipitation interpolations were performed with ArcGIS using the Natural Neighbor method. The USGS-National Map Viewer (NMV) website provided a 30-meter DEM - to interpolate high and low temperature ASCII grids using the Temperature Lapse Rate (TLR) method, to construct a D-8 flow direction grid for downhill redirection of soil-moisture saturated runoff toward non-saturated cells, and for aesthetic map creation. NMV also provided a modified Anderson land cover classification raster. The US Department of Agriculture-National Resource Conservation Service (NRCS) Web Soil Survey website provided shapefiles of soil water capacity and hydrologic soil groups. The Hargreaves and Samani method was implemented to determine evapotranspiration rates. The resulting SWB output data, in the form of ASCII grids are easily added to ArcGIS for quick visualization and data analysis (Figure 1). Calculated average recharge for 2008-2014 was 3537 inches/year, or 0.0174 acre feet/year. Recharge was 10.2% of the islands gross precipitation. The spatial distribution of the most significant recharge is in hotspots which dominate the residential hills above Avalon, followed by grassy/unvegetated areas
Isotopes to Study the coastal aquifer plain, Cap Bon, Tunisia
International Nuclear Information System (INIS)
Ben Hamouda, M. F.; Zouari, Kamel; Tarhouni, J.; Gaye, C.B.; Oueslati, M.N.
2005-01-01
The study area is located in the northeastern part of Tunisia about 60 km south of the Tunis city. It is bounded by the Gulf of Haematite in the East, Djebel Sidi Aberahmane in the West, The town of Nabeul in the south and the area of the town Kelibia in the north. The landscape is a coastal plain slightly sloping (3%) towards the sea. The groundwater of the Oriental coast aquifer system occurs mainly at two levels, a shallow aquifer up to depths of about 50 m whose reservoir is consisted by sediments of the Plio quaternary and a deep aquifer between about 150 and 400 m located in the sand stone formations of Miocene of the anticline of Djebel Sidi Abderrahmene. The climate of the region is semi-arid to sub-humid and of Mediterranean type. There are no perennial rivers in this region; but intense storms occasionally cause surface runoff, which is discharged by the oueds. The study is related to a technical cooperation project with the International Atomic Energy Agency, Vienna, Austria, aimed at the use of isotope techniques to study the seawater intrusion into the coastal aquifers of Cap Bon in Tunisia. In this regard, a better understanding of the recharge and flow regime as well as the origin or salinity of the groundwater was required. To reach this goal, isotope and geochemical investigations were carried out. Water samples were taken from wells, boreholes from deep and shallow aquifer of the Oriental coastal aquifer located between Beni Khiar in the south and Kelibia in the north. The samples were analysed for their chemical and isotopic compositions (18O, 2H, 3H, 13C, 14C, 34S). In the following, the results of these analyses are presented and discussed in terms of the recharge and flow regime of the groundwater and the origin and evolution of its salinity. The results of geochemical and isotopic studies have shown that the groundwater is very eterogeneous and suggest the aquifer is replenished by recent water coming from direct infiltration from rain. At
International Nuclear Information System (INIS)
Nada, A.; Aly, A.I.M.; Awad, M.; El-Behery, M.A.; Hamza, M.S.
1991-01-01
An environmental isotopes and hydrochemical study was conducted on the underground water bearing strata in the northern part of Wadi El-Arish area, sinai. Wadi El-Arish area represents one of the most important areas for future agricultural expansion in the sinai peninsula. The purpose of the study is to determine whether the groundwater is recently recharged or not in order to adopt an efficient management policy. The hydrochemical results indicate the meteoric origin of the water with some contribution from sea water and old marine water. The tritium data confirm the meteoric origin of the water and indicate the recharge of groundwater in the study area in the last 20 years. The stable environmental isotopic composition of the groundwater (oxygen-18 and deuterium) reflects more or less the isotopic composition of precipitation and flooding within the delta of the wadi to infiltration. There is also a possibility, of contribution from palea-water (depleted in the environmental stable isotopes) in some wells by leaking through faulting in this area.7 fig,2 tab
Deuterium isotope composition of palaeoinfiltration water trapped in speleothems
International Nuclear Information System (INIS)
Rozanski, K.
1987-05-01
Analytical and methodological aspects of combined isotope investigations of carbonate cave deposits are thoroughly discussed in the report. Weight is put on isotope analyses of fluid inclusions (D and 18 O content) extracted from speleothems of known age. Dating was done by the 230 Th/ 234 U ratio method. Isotopic analyses of speleothems originating from European caves allowed some important conclusions to be formulated regarding past climatic and environmental conditions prevailing over the European continent during the last 300,000 yrs: a) δD values of fluid inclusions suggest a remarkable constancy of the heavy-isotope content of European palaeoinfiltration waters recharged during interglacial periods, b) a climate-induced, long-term changes in isotopic composition of precipitation and surface air temperature over Europe can be characterized by the deuterium gradient of ca.1 4 deg./oo/deg. C, c) an apparent constancy of the continental gradient in deuterium content of European palaeoinfiltration waters as judged from the fluid inclusion data suggests that atmospheric circulation over Europe did not undergo substantial changes for at least 300,000 years
A rechargeable carbon-oxygen battery
DEFF Research Database (Denmark)
2014-01-01
The invention relates to a rechargeable battery and a method to operate a rechargeable battery having high efficiency and high energy density for storing energy. The battery stores electrical energy in the bonds of carbon and oxygen atoms by converting carbon dioxide into solid carbon and oxygen....
Isotopic studies in soil and plant nutrition
International Nuclear Information System (INIS)
Pasricha, N.S.
2001-01-01
One of the most important peaceful applications of isotopes is in research for the enhancement of our understanding for increased crop production and better management of resources with higher economic efficiency and environmental safety. Nuclear techniques helped in generating useful information on such aspects as use-efficiency of fertilizer nutrients, quantifying their losses from soil and their biological transformations. Such information was, hitherto, obtained indirectly by conventional methods. Radio and stable isotopes have also been successfully employed for getting information in such diverse fields as soil erosion, turnover of soil organic matter, pesticide retention in soil ground water recharge etc. The property of 137 Cs adhering tightly to certain exchange surface in soil and its chemically inert nature has made it a useful tool for soil erosion studies. In this paper, applications of isotopes in the research and other such studies as degradation, movement and retention of pesticides, movement of nitrate in soil, biological and ammoniacal nitrogen fixation in soil is discussed
Directory of Open Access Journals (Sweden)
Y. Ganot
2017-09-01
Full Text Available We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors, and observation wells. During a month (January 2015 of continuous intensive MAR (2.45 × 106 m3 discharged to a 10.7 ha area, groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from ∼ 11 to ∼ 0.4 m d−1. This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments. Clogging processes at the pond-surface – abundant in many MAR operations – are negated by the high-quality desalinated seawater (turbidity ∼ 0.2 NTU, total dissolved solids ∼ 120 mg L−1 or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016 fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models.
Energy Technology Data Exchange (ETDEWEB)
Lambán, L.J., E-mail: javier.lamban@igme.es [Geological Survey of Spain (IGME) (Spain); Jódar, J., E-mail: jorge.jodar@upc.edu [Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Barcelona (Spain); Custodio, E., E-mail: emilio.custodio@upc.edu [Department of Geotechnical Engineering and Geosciences, Technical University of Catalonia (UPC), Barcelona (Spain); Soler, A., E-mail: albertsoler@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament Cristal lografia Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB) (Spain); Sapriza, G., E-mail: g.sapriza@usask.ca [Global Institute for Water Security, National Hydrology Research Centre (Canada); Soto, R., E-mail: r.soto@igme.es [Geological Survey of Spain (IGME) (Spain)
2015-02-15
The Ordesa and Monte Perdido National Park, located in the Southern Pyrenees, constitutes the highest karst system in Western Europe. No previous studies regarding its geochemical and isotopic groundwater characterization are available in this area. This work presents the results of field and sampling campaigns carried out between July 2007 and September 2013. The groundwater presents high calcium bicarbonate contents due to the occurrence of upper Cretaceous and lower Paleocene–Eocene carbonate materials in the studied area. Other relevant processes include dissolution of anhydrite and/or gypsum and incongruent dissolution of Mg-limestone and dolomite. The water stable isotopes (δ{sup 18}O, δ{sup 2}H) show that the oceanic fronts from the Atlantic Ocean are responsible for the high levels of precipitation. In autumn, winter, and spring, a deuterium excess is found in the recharge water, which could be related to local atmospheric transport of low-altitude snow sublimation vapour and its later condensation on the snow surface at higher altitude, where recharge is mostly produced. The recharge zones are mainly between 2500 m and 3200 m a.s.l. The tritium content of the water suggests short groundwater transit times. The isotopic composition of dissolved sulphate points to the existence of regional fluxes mixed with local discharge in some of the springs. This work highlights the major role played by the altitude difference between the recharge and discharge zones in controlling the chemistry and the vertical variability of the isotopic composition in high-altitude karst aquifers. - Highlights: • Environmental tracers are essential to study complex alpine karst aquifers. • The long presence of snow controls the deuterium excess in groundwater. • Seasonal δD content in springs depends on gap between recharge and discharge points. • The first hydrogeological characterization of the Ordesa National Park is presented. • Sulphate content in springs comes
International Nuclear Information System (INIS)
Kilani, S.F.
2003-01-01
This study presents a thorough investigation of recharge origins of the strategic Disi sandstone aquifer in southern Jordan. This aquifer is of substantial potential and huge extension most of which lies in Saudi Arabia. Disi groundwater infiltrated in the ground thousands of years ago and is not currently being replenished, therefore crucial management for this resource is very important. This aquifer is foreseen to provide 100 MCM/a of high quality drinking water to the Capital Amman in addition to the current use of about 60 MCM/a for agricultural activities in the area and to meet the water demand in the port of Aqaba. Origins and amount of recharge to groundwater is one critical aspect in resource management. A study to estimate recharge rate was conducted in the Quaternary sediments and sandstone's of Al Quwayra in southern Jordan where the average rainfall is less than 70 mm per year. Environmental chloride, deuterium and nitrate in the sand profiles in the vadose zone were the study tools. The study showed that recharge if present is a result of severe infrequent storm events and that the aquifer does not receive significant direct recharge from rain. The pollutant profiles in the unsaturated zone might give chronology of the recharge history
Dvory, N. Z.; Ronen, A.; Livshitz, Y.; Adar, E.; Kuznetsov, M.; Yakirevich, A.
2017-12-01
Sustainable groundwater production from karstic aquifers is primarily dictated by its recharge rate. Therefore, in order to limit over-exploitation, it is essential to accurately quantify groundwater recharge. Infiltration during erratic floods in karstic basins may contribute substantial amount to aquifer recharge. However, the complicated nature of karst systems, which are characterized in part by multiple springs, sinkholes, and losing/gaining streams, present a large obstacle to accurately assess the actual contribution of flood water to groundwater recharge. In this study, we aim to quantify the proportion of groundwater recharge during flood events in relation to the annual recharge for karst aquifers. The role of karst conduits on flash flood infiltration was examined during four flood and artificial runoff events in the Sorek creek near Jerusalem, Israel. The events were monitored in short time steps (four minutes). This high resolution analysis is essential to accurately estimating surface flow volumes, which are of particular importance in arid and semi-arid climate where ephemeral flows may provide a substantial contribution to the groundwater reservoirs. For the present investigation, we distinguished between direct infiltration, percolation through karst conduits and diffused infiltration, which is most affected by evapotranspiration. A water balance was then calculated for the 2014/15 hydrologic year using the Hydrologic Engineering Center - Hydrologic Modelling System (HEC-HMS). Simulations show that an additional 8% to 24% of the annual recharge volume is added from runoff losses along the creek that infiltrate through the karst system into the aquifer. The results improve the understanding of recharge processes and support the use of the proposed methodology for quantifying groundwater recharge.
Groundwater recharge estimates in the Athabasca and Cold Lake oil sands areas
International Nuclear Information System (INIS)
MacMillan, G.J.; Smith, A.D.
2009-01-01
Groundwater recharge estimates for the Cold Lake and Athabasca oil sands region were presented. New oil sands projects planned for the future will require approximately 150,000 m 3 per day of groundwater. Regulators and public agencies are now investigating the potential impacts of oil sands operations on both shallow groundwater and surface water in the region. Maximum yields from the aquifers are also being estimated. Measurements are currently being taken to determine transmissivity, hydraulic pressure, storage potential and leakage. Numerical models are currently used to determine saturated zone recharge estimates and water table fluctuations. Isotope tracers are also being used to determine where groundwater flow potential is vertical as well as to determine correction factors for hydrogeological and geochemical conditions at each site. Darcy's Law is used to determine heat flow in the groundwater aquifers. To date, the studies have demonstrated that drilling fluids have been recovered at groundwater sites. Wells are often installed near water supply and supply well networks. It was concluded that new water wells will need to be completed at various depths. Data were presented for aquifers and nest wells. refs., tabs., figs
Environmental isotopic and hydrochemical study of the coastal submarine springs in Lebanon and Syria
International Nuclear Information System (INIS)
Al-Charideh, A. R.
2007-08-01
The groundwater of major karst system and the submarine springs in the Syrian coastal limestone aquifer have been studied using chemical and isotopic techniques. Stable isotopes show that the groundwater and submarine springs originates from the direct infiltration of atmospheric water. The elevation of recharge zones feeding the Banyas area (400-600 m a.s.l). The δ 18 O e xtracted for the major submarine spring at Bassieh suggests a mean recharge area elevation of 600-700 m a.s.l. Based on the measured velocity and percentage of fresh water at the submarine springs outlet (Bassieh and Tartous), the estimated discharge rate is 350 million m 3 /y. Adopting a model with exponential time distribution, the mean turnover time of groundwater in the Al-sen spring was evaluated to be 60 years. A value of about 3.7 billion m 3 was obtained for the maximum groundwater reservoir size.(Author)
International Nuclear Information System (INIS)
Gross, G.W.; Hoy, R.N.
1980-04-01
Different approaches were used to study recharge and flow patterns in the Roswell, New Mexico, artesian basin. Isotope determination for tritium, deuterium, and oxygen-18 were made as a function of time and space. Observation well levels, springflow, and precipitation were analyzed by stochastic/numerical approaches. Also, a hydrogeologic survey was made of representative springs in the recharge zone on the basin western flank. An updated listing of tritium activity in precipitation, springs, surface runoff, and subsurface water from over 120 sampling sites in the basin covers 117 pages of the report. Substantial deep leakage contributions from the basin western flank must be included to account for the basin groundwater budget
Ganot, Y.; Ganot, Y.; Holtzman, R.; Weisbrod, N.; Nitzan, I.; Katz, Y.; Kurtzman, D.
2017-01-01
We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil senso...
Müller, Th.; Osenbrück, K.; Strauch, G.; Pavetich, S.; Al-Mashaikhi, K.-S.; Herb, C.; Merchel, S.; Rugel, G.; Aeschbach, W.; Sanford, Ward E.
2016-01-01
Multiple age tracers were measured to estimate groundwater residence times in the regional aquifer system underlying southwestern Oman. This area, known as the Najd, is one of the most arid areas in the world and is planned to be the main agricultural center of the Sultanate of Oman in the near future. The three isotopic age tracers 4He, 14C and 36Cl were measured in waters collected from wells along a line that extended roughly from the Dhofar Mountains near the Arabian Sea northward 400 km into the Empty Quarter of the Arabian Peninsula. The wells sampled were mostly open to the Umm Er Radhuma confined aquifer, although, some were completed in the mostly unconfined Rus aquifer. The combined results from the three tracers indicate the age of the confined groundwater is 100 ka in the central section north of the mountains, and up to and > one Ma in the Empty Quarter. The 14C data were used to help calibrate the 4He and 36Cl data. Mixing models suggest that long open boreholes north of the mountains compromise 14C-only interpretations there, in contrast to 4He and 36Cl calculations that are less sensitive to borehole mixing. Thus, only the latter two tracers from these more distant wells were considered reliable. In addition to the age tracers, δ2H and δ18O data suggest that seasonal monsoon and infrequent tropical cyclones are both substantial contributors to the recharge. The study highlights the advantages of using multiple chemical and isotopic data when estimating groundwater travel times and recharge rates, and differentiating recharge mechanisms.
International Nuclear Information System (INIS)
Racadio, Charles Darwin T.; Mendoza, Norman DS.; Castañeda, Soledad S.; Abaño, Susan P.; Rongavilla, Luis S.; Castro, Joey
2015-01-01
Groundwater has been the primary source of drinking water of about 50% of the people in the Philippines and the numbers continue to rise. However, data and information on groundwater resources are generally spasmodic or sparse in the country. A specific remedy to address this gap is the use of isotope hydrological techniques. A pilot project utilizing this technique was done in Water Resources Region X with the aim of demonstrating the effectiveness and efficiency of these approach in groundwater resources assessment. When optimized, the technique will be replicated in other areas of the country. Groundwater samples from springs deep wells hand pumps and dug wells and river water were collected within the study area from September 2012 to June 2014. Monthly integrated precipitation samples were also collected at different points within the study area from October 2012 to March 2015. Samples were analyzed for stable isotope (δ”2H and δ”1”8O) using Laser Water Isotope Analyzer and tritium for groundwater dating. Results showed that aquifers in the study area are recharged by infiltrated rain during the heavy rainfall moths (May to November for Cagayan-Tagaloan Basin, and December to April for Agusan Basin). Water in Agusan Basin is isotopically enriched compared with the water in Cagayan-Tagaloan Basin. There appears to be interaction between shallow unconfined aquifer and deep semi-confined aquifer in Cagayan de Oro City. Shallow aquifers appear to be recharged by local precipitation. Groundwater in the study area is of Ca-Mg-HCO 3 type, which is characteristic of dynamic water with short residence time. Tritium-helium aging puts the water at ages between 18 to 72 years. Recharged rates of 422 to 625 mm/year were calculated for Cagayan de Oro City.(author)
Groundwater Resources Isotope Study of Eastern and Southeastern Areas of Jordan
International Nuclear Information System (INIS)
Al-Momani, M. R.
2004-01-01
Since Jordan depends on the groundwater resources especially for municipal use so, water resources studies and development takes priority on the national level. For this reason the environmental isotope technique and application contributed and supported the hydrological studies as a research tool confirmed some scientific facts including natural and environmental changes of water resources. The isotope analyses has been implemented for upper and deep aquifer systems in the eastern and southeastern areas of Jordan for Hamad, Sirhan, Azraq and Jafr basins. The analyses included the stable isotopes for 18 O, Deuterium ( 2 H) and 13 C also the radioactive isotopes for Tritium ( 3 H ) and 14 C in nineties of the last century until 2002 and this indicates the following: * The origin and mechanism of the nonrenewable groundwater recharge in the deep aquifer systems of (B2/A7) Campanian and Turonian age for Hamad and Azraq basins has been defined. This refers that the groundwater recharge existed within humid, cold and wet climatologic conditions which is completely different from the present climate where the groundwater age exceeds thirty thousand years. * Also this indicates that the stable isotopic composition of the upper aquifers in Hamad and Sirhan basins in Shallala and Rijam aquifers (B5/B4) of Eocene and Paleocene age lie on the Global Meteoric Water Line (GMWL) where the deuterium excess (d) is 10 %. Actually this water is not tritiated and the 14 C content in the groundwater is close to zero which is a strong indication of humid and wet climate where the age of the groundwater range between 20000 and exceeds 300000 years. In comparison this situation with the same aquifer in Jafr basin located in the southeastern part of Jordan, there are differences in the deuterium excess (d), Tritium and 14 C content which depends on the climatologic conditions existed during the recharge period. Also the isotopic signaure for the middle groundwater system (B2/A7) and the
Hopkins, Candice B.
2013-01-01
Parties proposing residential development in the area of Mayfield, Idaho are seeking a sustainable groundwater supply. During 2011–12, the U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources, used geochemical tracers in the Mayfield area to evaluate sources of aquifer recharge and differences in groundwater residence time. Fourteen groundwater wells and one surface-water site were sampled for major ion chemistry, metals, stable isotopes, and age tracers; data collected from this study were used to evaluate the sources of groundwater recharge and groundwater residence times in the area. Major ion chemistry varied along a flow path between deeper wells, suggesting an upgradient source of dilute water, and a downgradient source of more concentrated water with the geochemical signature of the Idaho Batholith. Samples from shallow wells had elevated nutrient concentrations, a more positive oxygen-18 signature, and younger carbon-14 dates than deep wells, suggesting that recharge comes from young precipitation and surface-water infiltration. Samples from deep wells generally had higher concentrations of metals typical of geothermal waters, a more negative oxygen-18 signature, and older carbon-14 values than samples from shallow wells, suggesting that recharge comes from both infiltration of meteoric water and another source. The chemistry of groundwater sampled from deep wells is somewhat similar to the chemistry in geothermal waters, suggesting that geothermal water may be a source of recharge to this aquifer. Results of NETPATH mixing models suggest that geothermal water composes 1–23 percent of water in deep wells. Chlorofluorocarbons were detected in every sample, which indicates that all groundwater samples contain at least a component of young recharge, and that groundwater is derived from multiple recharge sources. Conclusions from this study can be used to further refine conceptual hydrological models of the area.
The use of environmental uranium isotopes in the study of the hydrology of the Burdekin Delta
International Nuclear Information System (INIS)
Campbell, B.L.
1977-03-01
Analyses of bore water samples from the Burdekin Delta, Queensland, show considerable variation in both the uranium concentration and the 234 U/ 238 U activity ratio. In many cases, the uranium concentration was closely correlated with the bicarbonate concentration, but not for waters with a very low uranium concentration. Mechanisms by which uranium can be removed from solution are discussed. They provide a basis for explaining the low uranium concentrations and, in some areas, the apparent lack of response of the aquifer to the input of uranium by recharge. The 234 U/ 238 U activity ratio is interpreted as a reflection of the extent of local interaction of infiltrating ground water with soil constituents. Measurement of the isotope activity ratio has confirmed the location of an area with significant recharge from the river into the aquifer system. The isotopic and supporting chemical data illustrate the complexity of the aquifer system. (author)
Ganot, Yonatan; Holtzman, Ran; Weisbrod, Noam; Nitzan, Ido; Katz, Yoram; Kurtzman, Daniel
2016-01-01
We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors and observation...
Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment
International Nuclear Information System (INIS)
MJ Fayer; EM Murphy; JL Downs; FO Khan; CW Lindenmeier; BN Bjornstad
2000-01-01
Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is known as the Hanford ILAW Performance Assessment (PA) Activity, hereafter called the ILAW PA project. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require predictions of contaminant migration from the facility. To make such predictions will require estimates of the fluxes of water moving through the sediments within the vadose zone around and beneath the disposal facility. These fluxes, loosely called recharge rates, are the primary mechanism for transporting contaminants to the groundwater. Pacific Northwest National Laboratory (PNNL) assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of recharge rates for current conditions and long-term scenarios involving the shallow-land disposal of ILAW. Specifically, recharge estimates are needed for a filly functional surface cover; the cover sideslope, and the immediately surrounding terrain. In addition, recharge estimates are needed for degraded cover conditions. The temporal scope of the analysis is 10,000 years, but could be longer if some contaminant peaks occur after 10,000 years. The elements of this report compose the Recharge Data Package, which provides estimates of recharge rates for the scenarios being considered in the 2001 PA. Table S.1 identifies the surface features and
Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment
Energy Technology Data Exchange (ETDEWEB)
MJ Fayer; EM Murphy; JL Downs; FO Khan; CW Lindenmeier; BN Bjornstad
2000-01-18
Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is known as the Hanford ILAW Performance Assessment (PA) Activity, hereafter called the ILAW PA project. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require predictions of contaminant migration from the facility. To make such predictions will require estimates of the fluxes of water moving through the sediments within the vadose zone around and beneath the disposal facility. These fluxes, loosely called recharge rates, are the primary mechanism for transporting contaminants to the groundwater. Pacific Northwest National Laboratory (PNNL) assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of recharge rates for current conditions and long-term scenarios involving the shallow-land disposal of ILAW. Specifically, recharge estimates are needed for a filly functional surface cover; the cover sideslope, and the immediately surrounding terrain. In addition, recharge estimates are needed for degraded cover conditions. The temporal scope of the analysis is 10,000 years, but could be longer if some contaminant peaks occur after 10,000 years. The elements of this report compose the Recharge Data Package, which provides estimates of recharge rates for the scenarios being considered in the 2001 PA. Table S.1 identifies the surface features and
International Nuclear Information System (INIS)
Jong Sung Ahn
1988-01-01
Environmental isotope-aided studies on river water and groundwater interaction in the Han River Basin in areas especially occupied by crystalline rocks and limestone have been undertaken. The result indicates that the groundwater in the Seoul area is recharged by the Han River whereas in non-urban areas it is replenished by the infiltration of precipitation, the crystalline rock aquifers are recharged by downward percolation of shallow groundwater stored in overlying alluvium. Older groundwater having a very low concentration of tritium, ranging from 0 to 2 TU, was observed at the lower Han River basin near Bupyeong. It may indicate that the water sampled was recharged at a much earlier time than the other groundwater sampled, maybe, as early as the pre-thermonuclear period. The same interaction study conducted in the Karst area has shown that there is clearly no systematic differences of tritium level between surface water and groundwater and that the residence time of groundwater in limestone is very short, probably not longer than a few months. The areas recharged by the water from the overlying alluvium into the sedimentary rock aquifer were restricted only along the Kumho River channel and its tributaries in a clastic sedimentary rock area. Bedrock groundwater whose tritium level and stable isotope composition were less than 14 TU and -6.8 respectively was observed in the central part of Taegu city. (author). 15 refs, 21 figs, 8 tabs
Isotopic composition of groundwater in semi-arid regions of Southern Africa
International Nuclear Information System (INIS)
Vogel, J.C.; Urk, H. van
1975-01-01
Although the isotope content of precipitation in the semi-arid regions of southern Africa is extremely variable, groundwater samples from the same district are found to have a remarkably constant isotopic composition. The oxygen-18 content of the underground water, in general, varies by about 0.5% in a given area. The differences that occur between different regions are sufficiently large to allow the groundwater of an area to be characterized by means of its oxygen-18 content. In order to localize the infiltration area of an aquifer, radiocarbon dating of the water is used. It appears that the groundwater contains, in general, less of the heavy isotopes than does the precipitation in the recharge area. This indicates that infiltration only takes place during periods of heavy rainfall. Examples are given where the isotope content of the groundwater is used to distinguish between different aquifers in the same region
Proposed artificial recharge studies in northern Qatar
Kimrey, J.O.
1985-01-01
The aquifer system in northern Qatar comprises a water-table aquifer in the Rus Formation which is separated by an aquitard from a partially confined aquifer in the top of the overlying Umm er Radhuma Formation. These two aquifers are composed of limestone and dolomite of Eocene and Paleocene age and contain a fragile lens of freshwater which is heavily exploited as a source of water for agricultural irrigation. Net withdrawals are greatly in excess of total recharge, and quality of ground water is declining. Use of desalinated seawater for artificial recharge has been proposed for the area. Artificial recharge, on a large scale, could stabilize the decline in ground-water quality while allowing increased withdrawals for irrigation. The proposal appears technically feasible. Recharge should be by injection to the Umm er Radhuma aquifer whose average transmissivity is about 2,000 meters squared per day (as compared to an average of about 200 meters squared per day for the Rus aquifer). Implementation of artificial recharge should be preceded by a hydrogeologic appraisal. These studies should include test drilling, conventional aquifer tests, and recharge-recovery tests at four sites in northern Qatar. (USGS)
Apparatus for reading and recharging condenser ionization chambers
International Nuclear Information System (INIS)
McCall, R.C.
1977-01-01
A metering circuit for a condenser ionization chamber is disclosed for simultaneously recharging the ionization chamber and reading out the amount of charge required to recharge the chamber. During the recharging process, the amount of charge necessary to recharge the ionization chamber capacitor is placed on an integrating capacitor in the metering apparatus. The resultant voltage across the integrating capacitor is a measure of the radiation to which the ionization chamber was exposed. 9 claims, 1 figure
NORTH CAROLINA GROUNDWATER RECHARGE RATES 1994
North Carolina Groundwater Recharge Rates, from Heath, R.C., 1994, Ground-water recharge in North Carolina: North Carolina State University, as prepared for the NC Department of Environment, Health and Natural Resources (NC DEHNR) Division of Enviromental Management Groundwater S...
Groundwater recharge: The intersection between humanity and hydrogeology
Smerdon, Brian D.; Drewes, Jörg E.
2017-12-01
Groundwater recharge is an essential part of subsurface water circulation and the beginning of groundwater flow systems that can vary in duration from days to millennia. Globally, there is a growing body of evidence suggesting that many of Earth's aquifers contain 'fossil' groundwater that was recharged more than 12,000 years ago (Jasechko et al., 2017), and a very small portion of groundwater that was recharged within the last 50 years (Gleeson et al., 2015). Together, this information demonstrates the irregular distribution of groundwater circulation within the Earth and the wide variability of recharge conditions that replenish aquifer systems (Befus et al., 2017). Knowledge of groundwater recharge rates and distribution are needed for evaluating and regulating the quantity and quality of water resources, understanding consequences of landscapes use, identifying where managed aquifer recharge can augment supply, and predicting how groundwater systems will respond to a changing climate. In-turn, these topics are of central importance for the health of humans and ecosystems, and security of food and energy. Yet, despite the global importance, quantifying groundwater recharge remains challenging as it cannot be measured directly, and there is uncertainty associated with all currently known estimation methods (Scanlon et al., 2002).
Quantifying potential recharge in mantled sinkholes using ERT.
Schwartz, Benjamin F; Schreiber, Madeline E
2009-01-01
Potential recharge through thick soils in mantled sinkholes was quantified using differential electrical resistivity tomography (ERT). Conversion of time series two-dimensional (2D) ERT profiles into 2D volumetric water content profiles using a numerically optimized form of Archie's law allowed us to monitor temporal changes in water content in soil profiles up to 9 m in depth. Combining Penman-Monteith daily potential evapotranspiration (PET) and daily precipitation data with potential recharge calculations for three sinkhole transects indicates that potential recharge occurred only during brief intervals over the study period and ranged from 19% to 31% of cumulative precipitation. Spatial analysis of ERT-derived water content showed that infiltration occurred both on sinkhole flanks and in sinkhole bottoms. Results also demonstrate that mantled sinkholes can act as regions of both rapid and slow recharge. Rapid recharge is likely the result of flow through macropores (such as root casts and thin gravel layers), while slow recharge is the result of unsaturated flow through fine-grained sediments. In addition to developing a new method for quantifying potential recharge at the field scale in unsaturated conditions, we show that mantled sinkholes are an important component of storage in a karst system.
Recharge signal identification based on groundwater level observations.
Yu, Hwa-Lung; Chu, Hone-Jay
2012-10-01
This study applied a method of the rotated empirical orthogonal functions to directly decompose the space-time groundwater level variations and determine the potential recharge zones by investigating the correlation between the identified groundwater signals and the observed local rainfall records. The approach is used to analyze the spatiotemporal process of piezometric heads estimated by Bayesian maximum entropy method from monthly observations of 45 wells in 1999-2007 located in the Pingtung Plain of Taiwan. From the results, the primary potential recharge area is located at the proximal fan areas where the recharge process accounts for 88% of the spatiotemporal variations of piezometric heads in the study area. The decomposition of groundwater levels associated with rainfall can provide information on the recharge process since rainfall is an important contributor to groundwater recharge in semi-arid regions. Correlation analysis shows that the identified recharge closely associates with the temporal variation of the local precipitation with a delay of 1-2 months in the study area.
On the combination of isotope hydrogeology with regional flow and transport modelling
International Nuclear Information System (INIS)
Barmen, G.A.
1992-01-01
Many different methods and tools can be used when trying to improve the information basis on which decisions are made for maintaining a quantitatively and qualitatively safe, long-term use of groundwater resources. In this thesis, classical hydrogeological examinations, hydrochemical investigations, environmental isotope studies, computerized groundwater flow modelling and radioisotope transport modelling have been applied to the large system of reservoirs in the sedimentary deposits of southwestern Scania, Sweden. The stable isotopes 2 H, 18 O and 13 C and the radioactive 3 H and 14 C have been measured and the results obtained can improve the estimations of the periods of recharge and the average circulation times of the groundwater reservoirs studied. A groundwater flow model based on finite difference techniques and a continuum approach has been modified by data from traditional hydrogeological studies. The computer code, NEWSAM, has been used to simulate steady-state and transient isotope transport in the area studied, taking into account advective transport with radioactive decay. The interacting groundwater resevoirs studied have been represented by a three-dimensional system of grids in the numerical model. A major merit of this combination of isotope hydrogeology and regional flow and transport modelling is that the isotope transport simulations help to demonstrate where zones particularly vulnerable to pollution are situated. These locations are chiefly the results of the hydrogeological characteristics traditionally examined, but they are revealed by means of the transport model. Subsequent, more detailed investigations can then be focussed primarily on these vulnerable zones. High contents of radioisotopes in the main aquifer of southwestern Scania may indicate that groundwater withdrawals have stimulated recharge from shallow aquifers and surface waters and that the risk of pollution has increased. (196 refs.) (au)
Peng, Tsung-Ren; Zhan, Wen-Jun; Tong, Lun-Tao; Chen, Chi-Tsun; Liu, Tsang-Sen; Lu, Wan-Chung
2018-03-01
A study in eastern Taiwan evaluated the importance of montane water contribution (MC) to adjacent valley-plain groundwater (VPG) in a tectonic suture zone. The evaluation used a ternary natural-tracer-based end-member mixing analysis (EMMA). With this purpose, VPG and three end-member water samples of plain precipitation (PP), mountain-front recharge (MFR), and mountain-block recharge (MBR) were collected and analyzed for stable isotopic compositions (δ 2H and δ 18O) and chemical concentrations (electrical conductivity (EC) and Cl-). After evaluation, Cl- is deemed unsuitable for EMMA in this study, and the contribution fractions of respective end members derived by the δ 18O-EC pair are similar to those derived by the δ 2H-EC pair. EMMA results indicate that the MC, including MFR and MBR, contributes at least 70% (679 × 106 m3 water volume) of the VPG, significantly greater than the approximately 30% of PP contribution, and greater than the 20-50% in equivalent humid regions worldwide. The large MC is attributable to highly fractured strata and the steep topography of studied catchments caused by active tectonism. Furthermore, the contribution fractions derived by EMMA reflect the unique hydrogeological conditions in the respective study sub-regions. A region with a large MBR fraction is indicative of active lateral groundwater flow as a result of highly fractured strata in montane catchments. On the other hand, a region characterized by a large MFR fraction may possess high-permeability stream beds or high stream gradients. Those hydrogeological implications are helpful for water resource management and protection authorities of the studied regions.
Estimation of potential rainfall recharge in the pothwar area
International Nuclear Information System (INIS)
Afzal, M.; Yaseen, M.
2015-01-01
Groundwater recharge is complex phenomenon to understand and describe because it cannot be seen with open eyes. We have to depend some theoretical assumptions to understand this complicated hidden natural underground water movement process. There are many factors affecting and controlling the water movement in soil profile. Groundwater use in district chakwal is of a fundamental importance to meet the rapidly expanding drinking and agricultural water requirements. The man factors contributing to groundwater recharge in chakwal are rainfall, evapotranspiration and geology. due to the semi arid climatic conditions of the area, this resource is almost the only key to economic development. There are a number of dug wells in the area where water is getting stored during rainy season. source and processes of recharge in humid areas are different compared with semi-arid areas. Due to the main resource of available water in the area, the potential groundwater recharge estimation could be good exercise to visulize the amount of rainwater entering the ground. For groundwater recharge estimation there are a number of simple and advanced techniques available. In the present study simple methods were used to estimate potential recharge due to available limited resources. Rainfall runoff, gravimetric and water table fluctuation methods were used to quantify rainfall recharge during the monsoon season. The average potential recharge estimated was 60% of the rainfall of 148 mm. Rainfall runoff and gravimetric methods were found to be comparable for short period potential recharge estimation while water table fluctuation method gives actual recharge and require longer period data. Potential recharge values were higher for area having grassland type vegetation and low for area covering shrubs and tick vegetation. (author)
Wireless rechargeable sensor networks
Yang, Yuanyuan
2015-01-01
This SpringerBrief provides a concise guide to applying wireless energy transfer techniques in traditional battery-powered sensor networks. It examines the benefits and challenges of wireless power including efficiency and reliability. The authors build a wireless rechargeable sensor networks from scratch and aim to provide perpetual network operation. Chapters cover a wide range of topics from the collection of energy information and recharge scheduling to joint design with typical sensing applications such as data gathering. Problems are approached using a natural combination of probability
isotopic and hydrochemical studies on the groundwater of the eastern part of nile delta
International Nuclear Information System (INIS)
Nada, A.A.I.
1984-01-01
the present work deals with the study of trace elements, chemical composition and isotopic composition of oxygen and hydrogen in groundwater in the eastern part of the nile delta, surface water from the nile and ismaillia canal and sea water from the mediterranean sea and suez canal. this study involves chemical analysis for water samples and distribution of trace elements and major elements, some water-rock interactions, groundwater recharge relationships between surface and groundwater and some flow mechanism. the combination between isotopic composition and chemical composition of surface and groundwater
Luo, Mingming; Chen, Zhihua; Zhou, Hong; Zhang, Liang; Han, Zhaofeng
2018-03-01
To be better understand the hydrological and thermal behavior of karst systems in South China, seasonal variations in flow, hydrochemistry and stable isotope ratios of five karst springs were used to delineate flow paths and recharge processes, and to interpret their thermal response. Isotopic data suggest that mean recharge elevations are 200-820 m above spring outlets. Springs that originate from high elevations have lower NO3 - concentrations than those originating from lower areas that have more agricultural activity. Measured Sr2+ concentrations reflect the strontium contents of the host carbonate aquifer and help delineate the spring catchment's saturated zone. Seasonal variations of NO3 - and Sr2+ concentrations are inversely correlated, because the former correlates with event water and the latter with baseflow. The mean annual water temperatures of springs were only slightly lower than the local mean annual surface temperature at the outlet elevations. These mean spring temperatures suggest a vertical gradient of 6 °C/vertical km, which resembles the adiabatic lapse rate of the Earth's stable atmosphere. Seasonal temperature variations in the springs are in phase with surface air temperatures, except for Heilongquan (HLQ) spring. Event-scale variations of thermal response are dramatically controlled by the circulation depth of karst systems, which determines the effectiveness of heat exchange. HLQ spring undergoes the deepest circulation depth of 820 m, and its thermal responses are determined by the thermally effective regulation processes at higher elevations and the mixing processes associated with thermally ineffective responses at lower elevations.
Stable-isotope studies of groundwaters in southeastern New Mexico
International Nuclear Information System (INIS)
Lambert, S.J.
1987-01-01
Oxygen-18/16 and deuterium/hydrogen ratio measurements have been made on groundwaters sampled according to specific field criteria applied during pump tests of the Rustler Formation in Nash Draw, a solution-subsidence valley west of the WIPP site in the northern Delaware Basin of southeastern New Mexico. Comparison of these data with similar measurements on other groundwaters from the northern Delaware Basin indicates two nonoverlapping populations of meteoric groundwaters. Most of the Rustler waters in Nash Draw and at the WIPP site and older waters from the eastern two-thirds of the Capitan Limestone constitute one population, while unconfined groundwaters originating as observable modern surface recharge to alluvium, the near-surface Rustler in southwestern Nash Draw, and the Capitan in the Guadalupe Mountains (Carlsbad Caverns) constitute the other. The isotopic distinction suggests that Rustler groundwater in most of Nash Draw and at the WIPP site is not receiving significant modern meteoric recharge. A likely explanation for this distinction is that meteoric recharge to most of the Rustler and Capitan took place in the geologic past under climatic conditions significantly different from the present. 25 refs., 4 figs., 2 tabs
Assessment of aquifer system in the city of Lahore, Pakistan using isotopic techniques
International Nuclear Information System (INIS)
Ahmad, M.; Rafiq, M.; Akram, W.; Tasneem, M.A.; Ahmad, N.; Iqbal, N.; Sajjad, M.I.
2002-01-01
Isotopic and geochemical techniques were applied to assess the groundwater replenishment mechanism, pollution levels and pollution sources in the city of Lahore, the second largest city of Pakistan where water supply has been based on the abstraction of groundwater. Isotopic and chemical data indicates that groundwater has major contribution from the river water up to the center of the city while at remaining locations it seems base-flow recharged by rains of distant area or mixed recharge from river and rains. In case of shallow groundwater, different local sources like irrigation canals, sewerage drains, local rain and maybe the leaking main supply lines also contribute. High tritium values of deep groundwater fed by river show its quick movement up to 8-10 Km. Deep groundwater in the adjacent area towards the center of the city, although fed by the river shows residence time of about 45 years. Recharge to shallow aquifer is generally quick as most of the sampling locations have high tritium values. Chemical data shows that groundwater is mainly of sodium bicarbonate and calcium bicarbonate type. The infiltrating river water is of calcium bicarbonate type which changes to sodium bicarbonate type at few kilometers away from the river due to cation exchange and calcite precipitation processes. Water quality was assessed for drinking purpose and it was noted that concentrations of several parameters exceed the norms of good quality drinking water in case of shallow groundwater. This study clearly indicated an increasing trend of groundwater nitrate concentrations. δ 15 N values of high nitrate waters reveal the localized pollution from sewerage drains. Bacterial contamination of groundwater especially at locations near the drains also proves the penetration of urban recharge from sewerage drains. (author)
Global synthesis of groundwater recharge in semiarid and arid regions
Scanlon, Bridget R.; Keese, K.E.; Flint, A.L.; Flint, L.E.; Gaye, C.B.; Edmunds, W.M.; Simmers, I.
2006-01-01
Global synthesis of the findings from ∼140 recharge study areas in semiarid and arid regions provides important information on recharge rates, controls, and processes, which are critical for sustainable water development. Water resource evaluation, dryland salinity assessment (Australia), and radioactive waste disposal (US) are among the primary goals of many of these recharge studies. The chloride mass balance (CMB) technique is widely used to estimate recharge. Average recharge rates estimated over large areas (40–374 000 km2) range from 0·2 to 35 mm year−1, representing 0·1–5% of long-term average annual precipitation. Extreme local variability in recharge, with rates up to ∼720 m year−1, results from focussed recharge beneath ephemeral streams and lakes and preferential flow mostly in fractured systems. System response to climate variability and land use/land cover (LU/LC) changes is archived in unsaturated zone tracer profiles and in groundwater level fluctuations. Inter-annual climate variability related to El Niño Southern Oscillation (ENSO) results in up to three times higher recharge in regions within the SW US during periods of frequent El Niños (1977–1998) relative to periods dominated by La Niñas (1941–1957). Enhanced recharge related to ENSO is also documented in Argentina. Climate variability at decadal to century scales recorded in chloride profiles in Africa results in recharge rates of 30 mm year−1 during the Sahel drought (1970–1986) to 150 mm year−1 during non-drought periods. Variations in climate at millennial scales in the SW US changed systems from recharge during the Pleistocene glacial period (≥10 000 years ago) to discharge during the Holocene semiarid period. LU/LC changes such as deforestation in Australia increased recharge up to about 2 orders of magnitude. Changes from natural grassland and shrublands to dryland (rain-fed) agriculture altered systems from discharge (evapotranspiration, ET) to recharge in
International Nuclear Information System (INIS)
Benhamouda, M.F.
1997-01-01
The groundwater table studied here is located in the plain of Kairouan and it is one of the main underground resources in the Centre of Tunisia. This region is characterized by a semi arid climate with high intensity of rain that causes flooding of Kairouan City. This study has two objectives namely: 1- To develop a technical process of this recharge. The experiment was realized at two sites. In each site were installed 3 neutron probe access tubes to the depth of the level of the ground water table.Successive measurements were taken in each tube in function of depth and time to follow up the hydrodynamics of the recharge of the water table. Neutron and gamma probes were used and compared with respect to measured water content.Each access tube for a fixed time give a water content profile which shows the dynamics of actual recharge and the previous recharge. this technique can help the developer to make decision concerning the recharge parameters and, particularly, the flow rate and the opportunity time to get the best recharge water efficiency. 2- To analyse the concentration of stable and radioactive isotopes in the water of the plain of kairouan. Samples were taken from the shallow and deep water table. The obtained results are helpful to specify the origin of the water. Geochemical analysis were also done to clear the spatial variability of the quality of water. To reach the fore mentioned objectives, a survey of wells using those resources was made. Samples were taken from all surveilled wells in this investigation. water samples were taken from the deep and shallow aquifers and to determine salt concentration as well as stable and radioactive element (O18, H2, C13, C14, H3). The results obtained from chemical analysis showed no clear spatial variability of water quality between the two aquifers. However the isotopic study gave two types of results: First: A significant difference between ages of the water coming from the shallow and the deep ground water
Blok, Bertil; Van Kerrebroeck, Philip; de Wachter, Stefan; Ruffion, Alain; Van der Aa, Frank; Jairam, Ranjana; Perrouin-Verbe, Marie; Elneil, Sohier
2018-02-01
The RELAX-OAB study is designed to confirm the safety, efficacy, and technical performance of the Axonics r-SNM System, a miniaturized, rechargeable SNM system approved in Europe and Canada for the treatment of bladder and bowel dysfunction. The purpose of this article is to describe study subjects' ability to charge the rechargeable neurostimulator and to document their neurostimulator program settings and recharge interval over time. Fifty-one OAB patients were implanted in a single-stage procedure. These results represent the 3-month charging experience for 48 subjects who completed the 3-month follow-up. Recharge intervals were estimated using therapy stimulation settings and subject experience was evaluated using questionnaires. Forty-seven of forty-eight (98%) subjects were able to successfully charge their device prior to follow-up within 1-month post-implant. At 3-month post-implant, 98% of subjects were able to charge prior to their follow-up visit. Average stimulation amplitude across all subjects was 1.8 mA (±1.1 mA). A total of 69% of subjects had ≥14-day recharge intervals (time between charging) and 98% of subjects had ≥7-day recharge interval. No charging related adverse events occurred. Study subjects were able to charge the Axonics r-SNM System and stimulation settings provided 2 weeks of therapy between recharging for most subjects. Subject satisfaction indicates that subjects are satisfied with rechargeable SNM therapy. © 2018 The Authors. Neurourology and Urodynamics Published by Wiley Periodicals, Inc.
NTS groundwater recharge study, FY 1992
International Nuclear Information System (INIS)
Lyles, B.F.; Mihevc, T.M.
1992-10-01
Groundwater recharge from precipitation is thought by many scientists to be extremely low in Southem Nevada; however, no direct measurements of recharge have been made to substantiate this hypothesis. Three geomorphic regions have been identified as potential areas of groundwater recharge at the Nevada Test Site (NTS): mesas, washes, and lowlands. Eight recharge monitoring stations have been installed to monitor each of these regions; four of the stations are on Pahute/Rainier Mesa, two stations are in Fortymile Wash, one station is in a transition area between the mesas and the lowlands (Whiterock Spring), and one station is located in Yucca Flat at the bottom of the U-3fd crater. An additional station is proposed for Frenchman Flat near the Area 5 mixed waste facility; however, the instrumentation of that site has been delayed due to the complex permitting process associated with instrument installation near the mixed waste facility. Digital data were collected from eight sites during FY 1992
Energy Technology Data Exchange (ETDEWEB)
Blaser, P.C., E-mail: petra.blaser@petraconsult.com [Petraconsult buero fuer angewandte geologie dipl. geol. petra c. blaser, Bergstrasse 269, CH 8707 Uetikon am See (Switzerland); Coetsiers, M. [Laboratory for Applied Geology and Hydrogeology, Ghent University, B-9000 Ghent (Belgium); Aeschbach-Hertig, W. [Institut fuer Umweltphysik, Universitaet Heidelberg, D-69120 Heidelberg (Germany); Kipfer, R. [Department of Water Resources and Drinking Water, Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf (Switzerland)] [Institute of Isotope Geochemistry and Mineral Resources, ETH Zurich, CH-8092 Zurich (Switzerland); Van Camp, M. [Laboratory for Applied Geology and Hydrogeology, Ghent University, B-9000 Ghent (Belgium); Loosli, H.H. [Department of Climate and Environmental Physics, University of Bern, CH 3012 Bern (Switzerland); Walraevens, K. [Laboratory for Applied Geology and Hydrogeology, Ghent University, B-9000 Ghent (Belgium)
2010-03-15
The particular objective of the present work is the development of a new radiocarbon correction approach accounting for palaeoclimate conditions at recharge and hydrochemical evolution. Relevant climate conditions at recharge are atmospheric pCO{sub 2} and infiltration temperatures, influencing C isotope concentrations in recharge waters. The new method is applied to the Ledo-Paniselian Aquifer in Belgium. This is a typical freshening aquifer where recharge takes place through the semi-confining cover of the Bartonian Clay. Besides cation exchange which is the major influencing process for the evolution of groundwater chemistry (particularly in the Bartonian Clay), also mixing with the original porewater solution (fossil seawater) occurs in the aquifer. Recharge temperatures were based on noble gas measurements. Potential infiltration water compositions, for a range of possible pCO{sub 2}, temperature and calcite dissolution system conditions, were calculated by means of PHREEQC. Then the sampled groundwaters were modelled starting from these infiltration waters, using the computer code NETPATH and considering a wide range of geochemical processes. Fitting models were selected on the basis of correspondence of calculated {delta}{sup 13}C with measured {delta}{sup 13}C. The {sup 14}C modelling resulted in residence times ranging from Holocene to Pleistocene (few hundred years to over 40 ka) and yielded consistent results within the uncertainty estimation. Comparison was made with the {delta}{sup 13}C and Fontes and Garnier correction models, that do not take climate conditions at recharge into account. To date these are considered as the most representative process-oriented existing models, yet differences in calculated residence times of mostly several thousands of years (up to 19 ka) are revealed with the newly calculated ages being mostly (though not always) younger. Not accounting for climate conditions at recharge (pCO{sub 2} and temperature) is thus producing
The contribution of environmental isotopes to studies of large aquifers in Morocco
International Nuclear Information System (INIS)
Kabbaj, A.; Zeryouhi, I.; Carlier, Ph.
1979-01-01
The geochemistry of environmental isotopes has been used for the study of various aquifers in Morocco, some of which are large, such as the Charf el Akab in the Tangiers area, the Oum er Rbia basin and the Turonian aquifer of the Tadla, the free groundwater of the Quaternary lacustrine limestones of the Sais Plain and the Lias limestone aquifer. These isotope studies take hydrogeochemical data into account and have made it possible to determine the conditions of recharge of the aquifers, to distinguish waters of different origin from the Atlas Mountains or from the Phosphate Plateau in the Tadla Basin and the Sais plain, to estimate the recharge of one aquifer by another - for example groundwater of the Lias limestones passing via the folds of the Sais Plain into the lacustrine limestone aquifer - and to test the homogeneity or heterogeneity of these aquifers and their tightness (e.g. the Turonian aquifer of the Tadla and the special case of the Charf el Akab in relation to the marine environment). Altogether, these results made it possible to test the value of the techniques used and to specify the general conditions in which they can profitably be used. (author)
Delineation of groundwater recharge areas, western Cape Cod, Massachusetts
Masterson, John P.; Walter, Donald A.
2000-01-01
The unconfined sand-and-gravel aquifer in western Cape Cod, Massachusetts, which is the sole source of water supply for the communities in the area, is recharged primarily from precipitation. The rate of recharge from precipitation is estimated to be about 26 inches per year (in/yr), or about 60 percent of the precipitation rate. This recharge rate yields a flow through the aquifer of about 180 million gallons per day (Mgal/d). Groundwater flows radially outward from the top of the water-table mound in the north-central part of the flow system toward the coast, as indicated by the water-table contours on the large map on this sheet. Recharge that reaches the water table near the top of the mound travels deeper through the aquifer than recharge that reaches the water table closer to the coast. All recharge to the aquifer ultimately discharges to pumping wells, streams, or coastal areas; however, some of this recharge may flow first through kettle ponds before eventually reaching these discharge points.
Scholl, M.A.; Cozzarelli, I.M.; Christenson, S.C.
2006-01-01
Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals in the top 2 m of the saturated zone from a leachate-contaminated well and an uncontaminated well, and analyzed for ??18O, ??2H, non-volatile dissolved organic carbon (NVDOC), SO42-, NO3- and Cl-. Monthly recharge amounts were quantified using the offset of the ??18O or ??2H from the local meteoric water line as a parameter to distinguish water types, as evaporation and methanogenesis caused isotopic enrichment in waters from different sources. Presence of dissolved SO42- in the top 1 to 2??m of the saturated zone was associated with recharge; SO42- averaged 2.2??mM, with maximum concentrations of 15??mM. Nitrate was observed near the water table at the contaminated site at concentrations up to 4.6??mM. Temporal monitoring of ??2H and SO42- showed that vertical transport of recharge carried SO42- to depths up to 1.75??m below the water table, supplying an additional electron acceptor to the predominantly methanogenic leachate plume. Measurements of ??34S in SO42- indicated both SO42- reduction and sulfide oxidation were occurring in the aquifer. Depth-integrated net SO42- reduction rates, calculated using the natural Cl- gradient as a conservative tracer, ranged from 7.5 ?? 10- 3 to 0.61??mM??d- 1 (over various depth intervals from 0.45 to 1.75??m). Sulfate reduction occurred at both the contaminated and uncontaminated sites; however, median SO42- reduction rates were higher at the contaminated site. Although estimated SO42- reduction rates are relatively high, significant decreases in NVDOC were not observed at the contaminated site. Organic compounds more labile than the leachate NVDOC may be
Scholl, Martha A; Cozzarelli, Isabelle M; Christenson, Scott C
2006-08-10
Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals in the top 2 m of the saturated zone from a leachate-contaminated well and an uncontaminated well, and analyzed for delta(18)O, delta(2)H, non-volatile dissolved organic carbon (NVDOC), SO(4)(2-), NO(3)(-) and Cl(-). Monthly recharge amounts were quantified using the offset of the delta(18)O or delta(2)H from the local meteoric water line as a parameter to distinguish water types, as evaporation and methanogenesis caused isotopic enrichment in waters from different sources. Presence of dissolved SO(4)(2-) in the top 1 to 2 m of the saturated zone was associated with recharge; SO(4)(2-) averaged 2.2 mM, with maximum concentrations of 15 mM. Nitrate was observed near the water table at the contaminated site at concentrations up to 4.6 mM. Temporal monitoring of delta(2)H and SO(4)(2-) showed that vertical transport of recharge carried SO(4)(2-) to depths up to 1.75 m below the water table, supplying an additional electron acceptor to the predominantly methanogenic leachate plume. Measurements of delta(34)S in SO(4)(2-) indicated both SO(4)(2-) reduction and sulfide oxidation were occurring in the aquifer. Depth-integrated net SO(4)(2-) reduction rates, calculated using the natural Cl(-) gradient as a conservative tracer, ranged from 7.5x10(-3) to 0.61 mM.d(-1) (over various depth intervals from 0.45 to 1.75 m). Sulfate reduction occurred at both the contaminated and uncontaminated sites; however, median SO(4)(2-) reduction rates were higher at the contaminated site. Although estimated SO(4)(2-) reduction rates are relatively high, significant decreases in NVDOC were not observed at the contaminated
International Nuclear Information System (INIS)
Kamarudin Samuding; Noor Akhmal Kamarudin; Mohd Shahrizal Mohamed Sharifodin; Azrul Arifin; Kamaruzaman Mohamad
2016-01-01
An investigation of geothermal resources at Ulu Slim has been carried out using integrated environmental isotope and hydro-geochemical techniques. Environmental isotope Oxygen-18 ("1"8O) and Deuterium ("2H) and Tritium ("3H) were used to identify the recharge zones and origin of the water, whereas the hydro-geochemical technique is used to determine the water type and the level of solutes in the geothermal waters out flowing at the surface as well as in shallow and deep groundwater system. The sampling programme includes precipitations, surface waters, hot springs, groundwater for isotopes and hydro-geochemical analyses. The plot graph of (δ"1"8O vs δ"2H) show that the stable isotope composition of hot spring is relatively depleted as compared to surface water and groundwater. This indicates that the recharge of the hot spring is likely to occur from farther and higher elevation areas of the geothermal system. Tritium content in hot spring, groundwater and surface water is ranged between 0.85 - 0.92 TU, 0.81- 1.05 TU, 1.60-2.07 TU respectively. The values of TU in hot spring and groundwater is seen similar suggests that these samples are older than the surface water. Based on the plot of Ternary Major Anion diagram (Cl-SO_4- HCO_3) and Tri-linear Piper diagram, all the water samples are identified from the type of bicarbonate (HCO_3). Nevertheless, the content of sodium (Na) in hot spring is detected relatively higher as compared to surface water. Tri-linear Piper diagram also shows that there is no mixing process between hot spring and surface water. (author)
Modeling Recharge - can it be Done?
Verburg, K.; Bond, W. J.; Smith, C. J.; Dunin, F. X.
2001-12-01
In sub-humid areas where rainfall is relatively low and sporadic, recharge (defined as water movement beyond the active root zone) is the small difference between the much larger numbers rainfall and evapotranspiration. It is very difficult to measure and often modeling is resorted to instead. But is modeling this small number any less difficult than measurement? In Australia there is considerable debate over the magnitude of recharge under different agricultural systems because of its contribution to rising saline groundwater levels following the clearing of native vegetation in the last 100 years. Hence the adequacy of measured and modeled estimates of recharge is under close scrutiny. Results will be presented for the water balance of an intensively monitored 8 year sequence of crops and pastures. Measurements included meteorological inputs, evapotranspiration measured with a pair of weighing lysimeters, and soil water content was measured with TDR and neutron moisture meter. Recharge was estimated from the percolate removed from the lysimeters as well as, when conditions were suitable, from soil water measurements and combined soil water and evapotranspiration measurements. This data was simulated using a comprehensive soil-plant-atmosphere model (APSIM). Comparison with field measurements shows that the recharge can be simulated with an accuracy similar to that with which it can be measured. However, is either sufficiently accurate for the applications for which they are required?
Yang, Yuzhong; Wu, Qingbai; Hou, Yandong; Zhang, Zhongqiong; Zhan, Jing; Gao, Siru; Jin, Huijun
2017-12-15
Permafrost degradation on the Qinghai-Tibet Plateau (QTP) will substantially alter the surface runoff discharge and generation, which changes the recharge processes and influences the hydrological cycle on the QTP. Hydrological connections between different water bodies and the influence of thawing permafrost (ground ice) are not well understood on the QTP. This study applied water stable isotopic method to investigate the permafrost hydrological variabilities in Beiluhe Basin (BLB) on Central QTP. Isotopic variations of precipitation, river flow, thermokarst lake, and near-surface ground ice were identified to figure out the moisture source of them, and to elaborate the hydrological connections in permafrost region. Results suggested that isotopic seasonalities in precipitation is evident, it is showing more positive values in summer seasons, and negative values in winter seasons. Stable isotopes of river flow are mainly distributed in the range of precipitation which is indicative of important replenishment from precipitation. δ 18 O, δD of thermokarst lakes are more positive than precipitation, indicating of basin-scale evaporation of lake water. Comparison of δ I values in different water bodies shows that hydrology of thermokarst lakes was related to thawing of permafrost (ground ice) and precipitation. Near-surface ground ice in BLB exhibits different isotopic characteristics, and generates a special δD-δ 18 O relationship (freezing line): δD=5.81δ 18 O-23.02, which reflects typical freezing of liquid water. From isotopic analysis, it is inferred that near-surface ground ice was mainly recharged by precipitation and active layer water. Stable isotopic and conceptual model is suggestive of striking hydrological connections between precipitation, river flow, thermokarst lake, and ground ice under degrading permafrost. This research provides fundamental comprehensions into the hydrological processes in permafrost regions on QTP, which should be considered
Energy Technology Data Exchange (ETDEWEB)
Silva, Priscila Sousa, E-mail: priscila.silva@cprm.gov.br [Serviço Geológico do Brasil (CPRM), Manaus, AM (Brazil); Campos, José Eloi Guimarães; Cunha, Luciano Soares; Mancini, Luís Henrique, E-mail: eloi@unb.br, E-mail: lucianosc@unb.br, E-mail: lmancini@unb.br [Universidade de Brasília (UnB), Brasília, DF (Brazil)
2018-01-15
The Petrolina County, Pernambuco State, Brazil, presents specificities that make it unique from a hydrogeological point of view. Water resource scarcity is both a quantitative and qualitative issue. The climate is classified as semiarid, having low precipitation, along with high temperatures and evapotranspiration rates. Aquifer zones are related to low connected fractures resulting in a restricted water flow in the aquifer. The recharge is limited and the groundwater salinity is high. Stable isotope analyses of H and O were developed in groundwater samples (with different electrical conductivity) and surface water collected in a bypass channel flowing from the São Francisco River. The results were plotted in a δD ‰ versus δ{sup 18}O ‰ graph along with the curves of the global and local meteoric water line. Groundwater samples showed unexpected results showing a lighter sign pattern when compared to the meteoric waters. More negative δD and δ{sup 18}O values indicate an enrichment in light isotopes, which show that this process is not influenced by surface processes, where the enrichment occurs in heavy isotopes due to evaporation. The isotopic signature observed is interpreted either as resulting from the water-rock interaction, or as resulting from recharge from paleo rains. The waters are old and show restricted flow. So the water-rock contact time is extended. In the rock weathering processes, through the hydration of feldspars, there is preferential assimilation of heavy isotopes at the expense of the lighter ones that remain in the water. Analyses of the {sup 87}Sr/{sup 86}Sr ratio and isotopic groundwater dating assist in the interpretations. (author)
Argon isotopes as recorders of magmatic processes
Layer, P. W.; Gardner, J. E.; Mora Chaparro, J. C.; Arce, J. L.
2003-12-01
Argon isotopic ratios vary enough between different reservoirs (atmosphere, crust, mantle) and diffuse fast enough through most minerals at magmatic temperatures (700-1200 C) to make them ideal for looking at magma chamber dynamics. Indeed, diffusion is sufficiently fast to allow short time scales to be deciphered, setting argon apart from many other isotopic methods. A mineral's ability to retain "excess" argon (40Ar/36Ar ratios greater than the atmospheric value and apparent ages older than the known eruption age) during post-eruption cooling is key to Ar studies. Previous work shows that both phenocrysts (crystallizing in the magma chamber; e.g. Mt St. Helens; Layer and Gardner, 2001) and xenocrysts (introduced into the magma chamber; e.g Toba; Gardner et al., 2002) preserve excess argon, which enables magma chamber processes to be deciphered through the variable diffusion rates between crystal phases. Single crystal 40Ar/39Ar step-heating of biotite from the 10.5 ka eruption of Nevado de Toluca volcano, Mexico indicates that they are xenocrystic and resided for only a short (< 1 year) time in the magma before it erupted. The biotite has reaction rims of hornblende, orthopyroxene and plagioclase, and failed to grow experimentally at pressure-temperature conditions of the magma, confirming the xenocrystic nature of this phase. Single-step fusion of plagioclase phenocrysts from eruptions of El Chichon volcano, Mexico, shows evidence of excess (mantle) argon, whereas hornblende from the same eruptions contains little or none. In this case, faster diffusion of Ar in plagioclase than in hornblende allow plagioclase to incorporate excess argon during magma recharge; hornblende does not. Combining such results with other isotopic systems may in fact better determine magma chamber processes. At El Chichon, Sr isotopes suggest magma recharges ocurred (Tepley et al., 2000), whereas the argon isotopes suggest such pulses occurred just before each eruption. The fast and
Hartmann, Andreas; Jasechko, Scott; Gleeson, Tom; Wada, Yoshihide; Andreo, Bartolomé; Barberá, Juan Antonio; Brielmann, Heike; Charlier, Jean-Baptiste; Darling, George; Filippini, Maria; Garvelmann, Jakob; Goldscheider, Nico; Kralik, Martin; Kunstmann, Harald; Ladouche, Bernard; Lange, Jens; Mudarra, Matías; Francisco Martín, José; Rimmer, Alon; Sanchez, Damián; Stumpp, Christine; Wagener, Thorsten
2017-04-01
Karst develops through the dissolution of carbonate rock and results in pronounced spatiotemporal heterogeneity of hydrological processes. Karst groundwater in Europe is a major source of fresh water contributing up to half of the total drinking water supply in some countries like Austria or Slovenia. Previous work showed that karstic recharge processes enhance and alter the sensitivity of recharge to climate variability. The enhanced preferential flow from the surface to the aquifer may be followed by enhanced risk of groundwater contamination. In this study we assess the contamination risk of karst aquifers over Europe and the Mediterranean using simulated transit time distributions. Using a new type of semi-distributed model that considers the spatial heterogeneity of karst hydraulic properties, we were able to simulate karstic groundwater recharge including its heterogeneous spatiotemporal dynamics. The model is driven by gridded daily climate data from the Global Land Data Assimilation System (GLDAS). Transit time distributions are calculated using virtual tracer experiments. We evaluated our simulations by independent information on transit times derived from observed time series of water isotopes of >70 karst springs over Europe. The simulations indicate that, compared to humid, mountain and desert regions, the Mediterranean region shows a stronger risk of contamination in Europe because preferential flow processes are most pronounced given thin soil layers and the seasonal abundance of high intensity rainfall events in autumn and winter. Our modelling approach includes strong simplifications and its results cannot easily be generalized but it still highlights that the combined effects of variable climate and heterogeneous catchment properties constitute a strong risk on water quality.
GEOCHEMICAL AND ISOTOPIC INVESTIGATION OF LAKES IN THE TRENTO PROVINCE (ITALY
Directory of Open Access Journals (Sweden)
Marco Natale
2013-09-01
Full Text Available We present the geochemical composition and the stable isotope signature (18O/16O and 2H/1H of waters sampled from six lakes (Caldonazzo, Levico, Lases, Santa Colomba, Lamar and Santo located in the Province of Trento. The chemical compositions invariably revealed a HCO3-Ca hydrochemical facies; however slight differences were observed among the lakes, in relation to the lithologies distinguishing each lakes’drainage basin. Elemental ratios and in particular the Rb/Sr provide a discriminative tool to recognize the rocks that have been weathered; for example this ratio is high in water that interacted with volcanic ignimbrites (rhyolites, and low in rocks that interacted with carbonate rocks. Many other trace elements were analyzed, thus providing baseline data, and only arsenic displayed concentrations higher than the legislative threshold defined for drinking water (10mg/l, especially in Lake Levico (10-19 mg/l. As concerns the stable isotopes δD and δ18O, the obtained results approach the meteoric signature for waters sampled during the 2012 winter season. The waters sampled during two summers (2011 and 2012 displayed distinctive trends, reflecting the significant influence of evaporative processes. We emphasize that the annual differences recorded in the isotopic composition of distinct years are plausibly related to temperature changes and type of precipitation that recharged the lakes. In this light, the peculiar isotopic signature recorded in the year 2011 is possibly related to a significant snowy period, which greatly contributed to the lakes’ water budget. Interestingly, waters from Lake Santa Colomba were systematically different from all the other samples, possibly due to more effective evaporative processes, or to the involvement of deep underground recharge including fossil waters.
Groundwater regimes and isotopic studies, Ranger mine area, Northern Territory
Energy Technology Data Exchange (ETDEWEB)
Ahmad, M; Green, D C
1986-12-01
Three types of groundwater occur in the area of the Ranger mine. Type A groundwater occurs in the loose sands and gravels occupying the present day stream channels, Type B in the weathering profile and Type C occurs in relatively fresh fractured bedrock occupying open fractures and other cavities. The three types of groundwater can be distinguished both chemically and isotopically. Light stable isotope data suggest that most early rains are lost by evapotranspiration and have no imprint on the groundwater. Later in the wet season, the ground is saturated and groundwater recharge occurs on a regional scale. This younger groundwater sits on the older waters. Mixing is probably minimal as before any large scale mixing could occur, most younger waters are lost by evapotranspiration. Stable isotope data suggest that Type B groundwater in certain areas has some connection with evaporated surface water bodies. Stable isotope measurements for the pollution monitoring bores around the tailings dam do not indicate any connection with the polluted pond waters at the time of sample collection.
International Nuclear Information System (INIS)
Al-Charideh, A.
2010-03-01
Chemical and environmental isotopes have been used for studying the Upper Cretaceous aquifer systems in the Middle Orontes basin. The results indicate that the salinity of groundwater (0.2 to 2 g/l) reveals the dissolution of evaporate rocks is the main factor of high salinity especially in the Homes depression. The degree of salinity and its spaces distribution are basically related to the pattern of groundwater movement in the Upper cretaceous aquifer. The stable isotopes composition of groundwater in the Homes depression are more depleted by -2.5% and -17.0% for δ 18 O and δ 2 H respectively, than the groundwater from Hama elevation, suggested different origin and recharge time between this two groundwater groups. Estimates of their mean subsurface residence times have been constrained on the basis of 14 C D IC. The corrected ages of groundwater are recent and less to 10 thousand years in Hama uplift. However, the corrected age of groundwater in the Homs depression range between 10 to 25 thousand years indicate late Pleistocene recharge period. (author)
Energy Technology Data Exchange (ETDEWEB)
Grassa, Fausto [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa, 153, 90146 Palermo (Italy)]. E-mail: f.grassa@pa.ingv.it; Favara, Rocco [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa, 153, 90146 Palermo (Italy); Valenza, Mariano [Dipartimento CFTA, Universita di Palermo, Palermo, Via Archirafi, 36, 90123, Palermo (Italy)
2006-12-15
Here the authors present results of an isotope study on precipitation collected during a 2-a period from a rain-gauge network consisting of 6 stations located at different elevations in the Hyblean Mountains (HM) region, in south-eastern Sicily. The slope of the local meteoric water line ({delta}D = 6.50 {delta} {sup 18}O + 9.87) obtained for the region suggests that precipitation is affected by evaporation during rainfall events. The main variations in rainwater isotope composition are due to seasonal effects and elevation. An average {sup 2}H excess value of +21.2 per mille was found for precipitation events less affected by evaporation (i.e. when the rainfall was >65 mm/month). The spatial distribution of O isotope composition of precipitation shows a negative gradient from east and south to the inner areas. The depositional rate of Cl, used as a tracer of the origin of air masses, is highest at the coastal rain-gauges (SR and MRG stations) and lowest on the northern flank of the HM region (SC station). Based on these findings, a model is proposed for the origin of precipitation in the HM region, which assumes that a Mediterranean-derived component is the main source of moisture in the studied area. D/H and {sup 18}O/{sup 16}O ratios of inferred meteoric recharge waters were also compared with the isotope composition of waters collected from the main local springs and wells. The best linear fit of the {delta} {sup 18}O vs {delta}D relationship for Hyblean groundwater is {delta}D = 4.85 {delta} {sup 18}O-2.01. The enrichment of heavy isotopes in Hyblean groundwater is probably due to evaporation occurring after precipitation events or to a recharging contribution from surface waters (lakes or rivers) enriched in heavy isotopes.
International Nuclear Information System (INIS)
Grassa, Fausto; Favara, Rocco; Valenza, Mariano
2006-01-01
Here the authors present results of an isotope study on precipitation collected during a 2-a period from a rain-gauge network consisting of 6 stations located at different elevations in the Hyblean Mountains (HM) region, in south-eastern Sicily. The slope of the local meteoric water line (δD = 6.50 δ 18 O + 9.87) obtained for the region suggests that precipitation is affected by evaporation during rainfall events. The main variations in rainwater isotope composition are due to seasonal effects and elevation. An average 2 H excess value of +21.2 per mille was found for precipitation events less affected by evaporation (i.e. when the rainfall was >65 mm/month). The spatial distribution of O isotope composition of precipitation shows a negative gradient from east and south to the inner areas. The depositional rate of Cl, used as a tracer of the origin of air masses, is highest at the coastal rain-gauges (SR and MRG stations) and lowest on the northern flank of the HM region (SC station). Based on these findings, a model is proposed for the origin of precipitation in the HM region, which assumes that a Mediterranean-derived component is the main source of moisture in the studied area. D/H and 18 O/ 16 O ratios of inferred meteoric recharge waters were also compared with the isotope composition of waters collected from the main local springs and wells. The best linear fit of the δ 18 O vs δD relationship for Hyblean groundwater is δD = 4.85 δ 18 O-2.01. The enrichment of heavy isotopes in Hyblean groundwater is probably due to evaporation occurring after precipitation events or to a recharging contribution from surface waters (lakes or rivers) enriched in heavy isotopes
Rye, Robert O.; Truesdell, Alfred Hemingway; Morgan, Lisa A.
2007-01-01
The extraordinary number, size, and unspoiled beauty of the geysers and hot springs of Yellowstone National Park (the Park) make them a national treasure. The hydrology of these special features and their relation to cold waters of the Yellowstone area are poorly known. In the absence of deep drill holes, such information is available only indirectly from isotope studies. The δD-δ18O values of precipitation and cold surface-water and ground-water samples are close to the global meteoric water line (Craig, 1961). δD values of monthly samples of rain and snow collected from 1978 to 1981 at two stations in the Park show strong seasonal variations, with average values for winter months close to those for cold waters near the collection sites. δD values of more than 300 samples from cold springs, cold streams, and rivers collected during the fall from 1967 to 1992 show consistent north-south and east-west patterns throughout and outside of the Park, although values at a given site vary by as much as 8 ‰ from year to year. These data, along with hot-spring data (Truesdell and others, 1977; Pearson and Truesdell, 1978), show that ascending Yellowstone thermal waters are modified isotopically and chemically by a variety of boiling and mixing processes in shallow reservoirs. Near geyser basins, shallow recharge waters from nearby rhyolite plateaus dilute the ascending deep thermal waters, particularly at basin margins, and mix and boil in reservoirs that commonly are interconnected. Deep recharge appears to derive from a major deep thermal-reservoir fluid that supplies steam and hot water to all geyser basins on the west side of the Park and perhaps in the entire Yellowstone caldera. This water (T ≥350°C; δD = –149±1 ‰) is isotopically lighter than all but the farthest north, highest altitude cold springs and streams and a sinter-producing warm spring (δD = –153 ‰) north of the Park. Derivation of this deep fluid solely from present-day recharge is
Geostatistical estimates of future recharge for the Death Valley region
International Nuclear Information System (INIS)
Hevesi, J.A.; Flint, A.L.
1998-01-01
Spatially distributed estimates of regional ground water recharge rates under both current and potential future climates are needed to evaluate a potential geologic repository for high-level nuclear waste at Yucca Mountain, Nevada, which is located within the Death Valley ground-water region (DVGWR). Determining the spatial distribution of recharge is important for regional saturated-zone ground-water flow models. In the southern Nevada region, the Maxey-Eakin method has been used for estimating recharge based on average annual precipitation. Although this method does not directly account for a variety of location-specific factors which control recharge (such as bedrock permeability, soil cover, and net radiation), precipitation is the primary factor that controls in the region. Estimates of recharge obtained by using the Maxey-Eakin method are comparable to estimates of recharge obtained by using chloride balance studies. The authors consider the Maxey-Eakin approach as a relatively simple method of obtaining preliminary estimates of recharge on a regional scale
Fast reactor recharging device
International Nuclear Information System (INIS)
Artemiev, L.N.; Kurilkin, V.V.
1979-01-01
Disclosure is made of a device for recharging a fast-neutron reactor, intended for the transfer of fuel assemblies and rods of the control and safety system, having profiled heads to be gripped on the outside. The device comprises storage drums whose compartments for rods of the control and safety system are identical to compartments for fuel assemblies. In order to store and transport rods of the control and safety system from the storage drums to the recharging mechanism provision is made for sleeve-type holders. When placed in such a holder, the dimensions of a rod of the control and safety system are equal to those of a fuel assembly. To join a holder to a rod of the control and safety system, on the open end of each holder there is mounted a collet, whereas on the surface of each rod of the control and safety system, close to its head, there is provided an encircling groove to interact with the collet. The grip of the recharging mechanism is provided with a stop interacting with the collet in order to open the latter and withdraw the safety and control system rod from its holder
Seasonal variation in natural recharge of coastal aquifers
Mollema, Pauline N.; Antonellini, Marco
2013-06-01
Many coastal zones around the world have irregular precipitation throughout the year. This results in discontinuous natural recharge of coastal aquifers, which affects the size of freshwater lenses present in sandy deposits. Temperature data for the period 1960-1990 from LocClim (local climate estimator) and those obtained from the Intergovernmental Panel on Climate Change (IPCC) SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration with the Thornthwaite method. Potential recharge (difference between precipitation and potential evapotranspiration) was defined at 12 locations: Ameland (The Netherlands), Auckland and Wellington (New Zealand); Hong Kong (China); Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. The influence of variable/discontinuous recharge on the size of freshwater lenses was simulated with the SEAWAT model. The discrepancy between models with continuous and with discontinuous recharge is relatively small in areas where the total annual recharge is low (258-616 mm/year); but in places with Monsoon-dominated climate (e.g. Mumbai, with recharge up to 1,686 mm/year), the difference in freshwater-lens thickness between the discontinuous and the continuous model is larger (up to 5 m) and thus important to consider in numerical models that estimate freshwater availability.
Directory of Open Access Journals (Sweden)
Jui-Pin Tsai
2015-03-01
Full Text Available High recharge areas significantly influence the groundwater quality and quantity in regional groundwater systems. Many studies have applied recharge potential analysis (RPA to estimate groundwater recharge potential (GRP and have delineated high recharge areas based on the estimated GRP. However, most of these studies define the RPA parameters with supposition, and this represents a major source of uncertainty for applying RPA. To objectively define the RPA parameter values without supposition, this study proposes a systematic method based on the theory of parameter identification. A surrogate variable, namely the average storage variation (ASV index, is developed to calibrate the RPA parameters, because of the lack of direct GRP observations. The study results show that the correlations between the ASV indexes and computed GRP values improved from 0.67 before calibration to 0.85 after calibration, thus indicating that the calibrated RPA parameters represent the recharge characteristics of the study area well; these data also highlight how defining the RPA parameters with ASV indexes can help to improve the accuracy. The calibrated RPA parameters were used to estimate the GRP distribution of the study area, and the GRP values were graded into five levels. High and excellent level areas are defined as high recharge areas, which composed 7.92% of the study area. Overall, this study demonstrates that the developed approach can objectively define the RPA parameters and high recharge areas of the Choushui River alluvial fan, and the results should serve as valuable references for the Taiwanese government in their efforts to conserve the groundwater quality and quantity of the study area.
Recharge and discharge calculations to characterize the groundwater hydrologic balance
International Nuclear Information System (INIS)
Liddle, R.G.
1998-01-01
Several methods are presented to quantify the ground water component of the hydrologic balance; including (1) hydrograph separation techniques, (2) water budget calculations, (3) spoil discharge techniques, and (4) underground mine inflow studies. Stream hydrograph analysis was used to calculate natural groundwater recharge and discharge rates. Yearly continuous discharge hydrographs were obtained for 16 watersheds in the Cumberland Plateau area of Tennessee. Baseflow was separated from storm runoff using computerized hydrograph analysis techniques developed by the USGS. The programs RECESS, RORA, and PART were used to develop master recession curves, calculate ground water recharge, and ground water discharge respectively. Station records ranged from 1 year of data to 60 years of data with areas of 0.67 to 402 square miles. Calculated recharge ranged from 7 to 28 inches of precipitation while ground water discharge ranged from 6 to 25 inches. Baseflow ranged from 36 to 69% of total flow. For sites with more than 4 years of data the median recharge was 20 inches/year and the 95% confidence interval for the median was 16.4 to 23.8 inches of recharge. Water budget calculations were also developed independently by a mining company in southern Tennessee. Results showed about 19 inches of recharge is available on a yearly basis. A third method used spoil water discharge measurements to calculate average recharge rate to the mine. Results showed 21.5 inches of recharge for this relatively flat area strip mine. In a further analysis it was shown that premining soil recharge rates of 19 inches consisted of about 17 inches of interflow and 2 inches of deep aquifer recharge while postmining recharge to the spoils had almost no interflow component. OSM also evaluated underground mine inflow data from northeast Tennessee and southeast Kentucky. This empirical data showed from 0.38 to 1.26 gallons per minute discharge per unit acreage of underground workings. This is the
Application of isotopic techniques for study of ground water from karstic areas. 1. Origin of waters
International Nuclear Information System (INIS)
Feurdean, Victor; Feurdean, Lucia
2000-01-01
Environmental stable isotope method was used for study of ground water from karst of NE Dobrogea. Study area is in the vicinity of Danube Delta (declared in 1990 by UNESCO the Reserve of Biosphere) and presents scientific and ecological interest. Measurements of deuterium content of ground water show that waters are meteoric in origin, but at the same time the results showed that the water from two sampling points could not originate from local ground water and have their recharge area at high altitude and a considerable distance. According to the δD values the following categories of waters were established: - waters depleted in deuterium (δD 0 / 00 ) relative to δD values of surface and ground water in the geographic area from which they were collected. They represent most probably the intrusion of isotopically light water from high altitude sites (higher than 1000 m) through network of highly permeable karst channels. The discharge of this component of aquifer occurs both by conduct flow and by diffuse flow; - Waters tributaries to the Danube River (δD > -75 0 / 00 ) that have a small time variability of δD values; - Local infiltration waters, situated in the West side of the investigated area towards the continental platform of the Dobrogea (δD > -70 0 / 00 ). They present high time variability of δD values, due to distinct seasonal effects; - Waters originated in mixing processes between the waters with different isotopic content. The endmember one is heavier isotopic water that belongs to local recharged waters (local infiltration waters and waters tributary to Danube river) while the other endmember is the isotopically light water. (authors)
Isotopic characteristic of meteoric water and groundwater in Ahaggar massif (central Sahara)
International Nuclear Information System (INIS)
Saighi, O.; Michelot, J.L.; Filly, A.
2001-01-01
The mean contents of both oxygen-18 and deuterium in precipitation from the Ahaggar massif (central Sahara) are: δ 18 O = -3 per mille and 2 H = -15 per mille. The heterogeneity in meteoric events and the great scattering of these isotopic contents can be ascribed to the origins and the histories of air masses. The main contribution comes from the inflow of the Guinean monsoon during summer months. During winter, the N/W winds, arriving in the area from the Moroccan coast, provide some rains. The deuterium excess of these precipitation are up to +10 per mille, indicating that the air masses generating these rains are supplied by the recycling of the continental air moisture. Groundwater resources are produced in some little phreatic aquifers, which are recharged by sporadic wadi floods. Aquifer zones that are the most favourable are located in the valleys and occur as three overlying levels of unequal importance: the alluvial aquifer, the weathered zone of the underlying substratum and the deep aquifer of fissured basement. The alluvial aquifer contain weakly mineralised water (0.3 g/l). Their stable isotopes contents (δ 18 O∼ -2.7 per mille) and 14 C activity of them (> 100 pmc) are comparable to present meteoric water, allowing modern meteoric waters to be identified. The weathered zone groundwater's are more mineralised (0.8 g/l) and its isotopic contents (δ 18 O∼ -4.2 per mille) and intermediate radiocarbon activity, prove their old water component. The basement's groundwater are more mineralised (> 1 g/l) and their very depleted isotopic contents (δ 18 O∼ -9 per mille) diverge clearly from the present precipitation. Furthermore, the absence of 3 H and 14 C activity of them, prove an old heritage, resulting from recharge during the last humid episode of the Holocene. (author)
International Nuclear Information System (INIS)
Xiao Feng; Wang Zhiming; Li Sen
1995-01-01
Through the research on chemical compositions of various kinds of ground water, hydrogen and oxygen stable isotopes and radioactive isotopes in ground water in the study area, the shallow underground water (pore water) and the weathering fissure water in bedrock are distinguished. It is determined that the recharge area of ground water is the Paiyashan area. The main direction for the surface water and ground water runoff is SE-striking, in the meantime the lateral migration of ground water exists and recharges the shallow water and surface water in the form of springs. Based on the decay calculation of tritium and compared with the data from Hongkong observation station, the relative ages of water in the area have been established and they are divided into 3 age groups: (1) ground water with the shortest runoff time, having tritium concentration identical to that of recent meteoric water; (2) shallow ground water with the relative age of about 20 years; (3) low tritium water with the relative age of more than 30 years
Emulation of recharge and evapotranspiration processes in shallow groundwater systems
Doble, Rebecca C.; Pickett, Trevor; Crosbie, Russell S.; Morgan, Leanne K.; Turnadge, Chris; Davies, Phil J.
2017-12-01
In shallow groundwater systems, recharge and evapotranspiration are highly sensitive to changes in the depth to water table. To effectively model these fluxes, complex functions that include soil and vegetation properties are often required. Model emulation (surrogate modelling or meta-modelling) can provide a means of incorporating detailed conceptualisation of recharge and evapotranspiration processes, while maintaining the numerical tractability and computational performance required for regional scale groundwater models and uncertainty analysis. A method for emulating recharge and evapotranspiration processes in groundwater flow models was developed, and applied to the South East region of South Australia and western Victoria, which is characterised by shallow groundwater, wetlands and coastal lakes. The soil-vegetation-atmosphere transfer (SVAT) model WAVES was used to generate relationships between net recharge (diffuse recharge minus evapotranspiration from groundwater) and depth to water table for different combinations of climate, soil and land cover types. These relationships, which mimicked previously described soil, vegetation and groundwater behaviour, were combined into a net recharge lookup table. The segmented evapotranspiration package in MODFLOW was adapted to select values of net recharge from the lookup table depending on groundwater depth, and the climate, soil and land use characteristics of each cell. The model was found to be numerically robust in steady state testing, had no major increase in run time, and would be more efficient than tightly-coupled modelling approaches. It made reasonable predictions of net recharge and groundwater head compared with remotely sensed estimates of net recharge and a standard MODFLOW comparison model. In particular, the method was better able to predict net recharge and groundwater head in areas with steep hydraulic gradients.
Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu
2013-02-01
To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin.
Isotope hydrology in the Sahel zone
International Nuclear Information System (INIS)
1974-01-01
Northern Africa has recently experienced an exceptional period of severe drought. Practically no precipitation has been received during two or three years by large regions in the so-called Sahel zone, which extends over all Africa from West to East at a latitude between 10 and 20 degrees North in the following countries: Senegal, Mauritania, Mali, Upper Volta, Niger, Nigeria, Chad, Sudan and Ethiopia. Although precipitation is scarce even in normal years, important groundwater resources are present in the Sahei zone. However, groundwater is exploited mainly by dug wells, reaching only the upper part of the phreatic aquifer, which is also the one immediately affected by droughts (lowering of the water table). Deep groundwater is exploited only by a limited number of drilled wells. In recent years several hydrogeological projects have been financed by the United Nations through UNDP in the Sahel countries, with the purpose of locating and evaluating groundwater resources and of developing their exploitation. The International Atomic Energy Agency has taken or takes part in many of these projects by providing isotopic analyses of groundwater. Some of the most difficult questions to be answered in groundwater research in arid zones are: Is the recharge of a given aquifer also taking place at present? If so, from where does the major contribution to groundwater recharge come? What is the age of groundwater? Often it is not possible to answer these questions with the classical hydrogeological and geophysical methods above, but the techniques based on the so-called environmental isotopes ( 18 O and 2 H, 3 H and 14 C) may provide an answer. The information provided by isotope techniques is in many cases extremely valuable for a better understanding of groundwater resources and a better planning of their exploitation, despite the problems which always occur in actual cases. In fact, natural processes, like mixing or interaction with the aquifer material, or practical
Isotope hydrogeochemical characteristics of water bodies in Munigou, Sichuan
International Nuclear Information System (INIS)
Li Hongye; Yin Guan; Yang Junyi; Fan Xiao
2003-01-01
Munigou is a part of Huanglong -Jiuzhaigou national scenic in northern Sichuan province. By using isotope geochemistry technique of natural water to analyze the data of δ D, δ 18 O, tritium contents, deuterium excess parameters (d-excess) and element chemical analyses, we discusses the recharge, runoff, discharge and hydraulic relationship between the precipitation, terrain surface water, groundwater and main spring in the Munigou area. Pearl spring and Jadeite spring are major spring resources in this spot. Pearl spring is a hot spring that recharged by the precipitation that sourced from an elevation of more than 3700 m. The part of precipitation infiltrate underground and return the earth's surface after it exchanged quantity of heat with deep hot fluid. So the Pearl spring can be exploited as hot spring; The Jadeite spring is typical acidic karst water cold spring. The velocity of flow of the water in the Jadeite spring's aquifer is slower than the Pearl spring's and the water has long detained time. The spring water has a good quality and important economical value for natural mineral water; Most of runoff in Munigou recharged by precipitation and shallow groundwater. This recharge have seasonal variation and important for scenic spot. These discussed problems in article have far-reaching meaning on evaluation the exploited potential of the Pearl spring and Jadeite spring and is important to protecting and developing the precious natural resource in Munigou area. And provides reference for the similar researches too. (authors)
International Nuclear Information System (INIS)
Minissale, A.; Vaselli, O.
2011-01-01
Highlights: → Isotopic compositions of karstic springs in central Italy have been reviewed. → Isotopic gradients of rainfalls for elevations have been evaluated in an Alpine valley. → Karstic drops have been calculated by using isotopic compositions of springs. → Isotopic compositions of rainfalls in central Italy have been re-calculated using the isotopic compositions of karstic springs. - Abstract: This paper describes an indirect method to calculate the isotopic composition of rainfall by using the isotopic composition of karst springs fed by waters circulating in the most important regional aquifer of central Italy, i.e. the Mesozoic limestone sequence that forms the backbone of the Apennines. By using δ 18 O and δD data and the δ 18 O (and/or δD) average gradient for elevation, evaluated through the use of literature rainfall data and new measurements from a typical Alpine valley in northern Italy, the altitude of precipitation of their parent water has been re-calculated. Vertical descents of more than 2000 m, from recharge to discharge, have been assessed in some high flow-rate cold springs in the morphologically steep Adriatic sector of central Italy. A clear correlation between the vertical descents and more negative isotopic compositions at their relative emergence elevations is highlighted. In contrast, in the Tyrrhenian sector lower karstic drops (generally lower than 500 m) correlate with less negative isotopic composition of recharge areas. The δ 18 O iso-contour map of the 'recalculated' parent rainfall in central Italy is more detailed than any possible isotopic map of rainfall made using pluviometers, unless large number of rainfall collectors were deployed on mountaintops. The data also show that the isotopic composition of rainfall depends on the source of the storm water. In particular, precipitation is isotopically heavier when originating in the Mediterranean Sea, and lighter when formed in the Atlantic Ocean. Consequently, the
A Study Plan for Determining Recharge Rates at the Hanford Site Using Environmental Tracers
Energy Technology Data Exchange (ETDEWEB)
Murphy, E. M.; Szecsody, J. E.; Phillips, S. J.
1991-02-01
This report presents a study plan tor estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. The prediction of contaminant movement or transport is one aspect of performance assessment and an important step in the remedial investigation/feasibility study (RI/FS) process. In the past, recharge has been characterized by collecting lysimeter data. Although lysimeters can generate important and reliable data, their limitations include 1) fixed location, 2) fixed sediment contents, 3) edge effects, 4) low rates, and 5) relatively short duration of measurement. These limitations impact the ability to characterize the spatial distribution of recharge at the Hanford Site, and thus the ability to predict contaminant movement in the vadose zone. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, {sup 36}CI, {sup 3}H, and {sup 2}H/{sup 18}O. Atmospheric levels of {sup 36}CI and {sup 3}H increased during nuclear bomb testing in the Pacific, and the resulting "bomb pulse" or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resu~ed in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, {sup 129}I, and {sup 99}Tc. The radionuclides, in particular, reached a well-defined atmospheric peak in 1945. Atmospheric releases of {sup 129}I and {sup 99}Tc were greatly reduced by mid-1946, but nitrogen oxides continued to be released from the uranium separations facilities. As a result, the nitrate concentrations probably peaked in the mid-1950s, when the greatest number of separations facilities were operating
Chlorine stable isotope studies of old groundwater, southwestern Great Artesian Basin, Australia
International Nuclear Information System (INIS)
Zhang Min; Frape, Shaun K.; Love, Andrew J.; Herczeg, Andrew L.; Lehmann, B.E.; Beyerle, U.; Purtschert, R.
2007-01-01
Stable Cl isotope ratios ( 37 Cl/ 35 Cl) were measured in groundwater samples from the southwestern flow system of the Great Artesian Basin, Australia to gain a better understanding of the Cl - sources and transport mechanisms. δ 37 Cl values range from 0 per mille to -2.5 per mille (SMOC), and are inversely correlated with Cl - concentration along the inferred flow direction. The Cl isotopic compositions, in conjunction with other geochemical parameters, suggest that Cl - in groundwaters is not derived from salt dissolution. Mixing of the recharge water with saline groundwater cannot explain the relationship between δ 37 Cl and Cl - concentration measured. Marine aerosols deposited via rainfall and subsequent evapotranspiration appear to be responsible for the Cl - concentrations observed in wells that are close to the recharge area, and in groundwaters sampled along the southern transect. δ 37 Cl values measured in the leachate of the Bulldog shale suggest that the aquitard is the subsurface source of Cl - for the majority of groundwater samples studied. Diffusion is likely the mechanism through which Cl - is transported from the pore water of the Bulldog shale to the aquifer. However, a more detailed study of the aquitard rocks is required to verify this hypothesis
Beyer, Matthias; Gaj, Marcel; Hamutoko, Josefina Tulimeveva; Koeniger, Paul; Wanke, Heike; Himmelsbach, Thomas
2015-01-01
The stable water isotope deuterium ((2)H) was applied as an artificial tracer ((2)H2O) in order to estimate groundwater recharge through the unsaturated zone and describe soil water movement in a semi-arid region of northern central Namibia. A particular focus of this study was to assess the spatiotemporal persistence of the tracer when applied in the field on a small scale under extreme climatic conditions and to propose a method to obtain estimates of recharge in data-scarce regions. At two natural sites that differ in vegetation cover, soil and geology, 500 ml of a 70% (2)H2O solution was irrigated onto water saturated plots. The displacement of the (2)H peak was analyzed 1 and 10 days after an artificial rain event of 20 mm as well as after the rainy season. Results show that it is possible to apply the peak displacement method for the estimation of groundwater recharge rates in semi-arid environments via deuterium labelling. Potential recharge for the rainy season 2013/2014 was calculated as 45 mm a(-1) at 5.6 m depth and 40 mm a(-1) at 0.9 m depth at the two studied sites, respectively. Under saturated conditions, the artificial rain events moved 2.1 and 0.5 m downwards, respectively. The tracer at the deep sand site (site 1) was found after the rainy season at 5.6 m depth, corresponding to a displacement of 3.2 m. This equals in an average travel velocity of 2.8 cm d(-1) during the rainy season at the first site. At the second location, the tracer peak was discovered at 0.9 m depth; displacement was found to be only 0.4 m equalling an average movement of 0.2 cm d(-1) through the unsaturated zone due to an underlying calcrete formation. Tracer recovery after one rainy season was found to be as low as 3.6% at site 1 and 1.9% at site 2. With an in situ measuring technique, a three-dimensional distribution of (2)H after the rainy season could be measured and visualized. This study comprises the first application of the peak displacement method using a
Chemical and environmental isotope study of the basaltic aquifer systems of Yarmouk Basin (Syria)
International Nuclear Information System (INIS)
Kattan, Z.
1994-08-01
The water in the fissured basalt aquifer system, the Upper Jurassic aquifer of the Yarmouk Basin and the atmospheric precipitation have been investigated using chemical and environmental isotope techniques. The groundwaters flowing through the different aquifers are differentiated by their chemical ratios and their isotopic compositions. The evolution of chemical facies of groundwater from the recharge area towards the basin outlet is characterized by increasing of sodium and magnesium contents as a result of silicate leaching. The stable isotope compositions of precipitation and mountainous spring waters match the Mediterranean Meteoric Water Line, while the groundwaters from the central zone and from the major springs of the Yarmouk Basin are mixtures of freshwater, which is isotopically depleted and salty groundwater of Laja plateau area. The interpretations of tritium and radiocarbon ( 14 C) data indicate that the recharge zones of the groundwater in the Yarmouk Basin occur on the high-land of more than 1000 m of altitude. The residence time of the mountainous springs is short (of about 40 years or less). However, water ages corrected by Vogel's concept and Gonfiantini's Model show, in general, a range from 1000 to 11000 years for the central zone groundwater. The groundwater moves from the Mt. Hermon and Mt. Arab towards the central zone and from the north-east (i.e. the Laja plateau) towards south-west (i.e. the major springs). The radiometric flow velocities range from 20 to 60 m/year within the central zone, while the flow velocities from both sides of Mt. Hermon and Mt. Arab are lower (1-7 m/year). (author). 43 refs., 37 figs., 6 tabs
Geochemical processes during managed aquifer recharge with desalinated seawater
Ganot, Y.; Holtzman, R.; Weisbrod, N.; Russak, A.; Katz, Y.; Kurtzman, D.
2017-12-01
In this work we study the geochemical processes along the variably-saturated zone during managed aquifer recharge (MAR) with reverse-osmosis desalinated seawater (DSW) to an infiltration pond at the Menashe site, located above the Israeli coastal aquifer. The DSW is post-treated by calcite dissolution (remineralization) in order to meet the Israeli desalinated water quality criteria. Suction cups and monitoring wells inside the pond were used to monitor water quality during two MAR events on 2015 and 2016. Results show that cation exchange is dominant, driven by the high Ca2+ concentration in the post-treated DSW. Stable isotope analysis shows that the composition of the shallow groundwater is similar to the recharged DSW, but with enrichment of Mg2+, Na+, Ca2+ and HCO3-. A calibrated variably-saturated reactive transport model was used to predict the geochemical evolution during 50 years of MAR with two water quality scenarios: post-treated DSW and soft DSW (without post-treatment). The latter scenario was aimed to test soil-aquifer-treatment as an alternative post-treatment technique. In terms of water quality, the results of the two scenarios were found within the range of the desalinated water criteria. Mg2+ enrichment was stable ( 2.5 mg L-1), higher than the zero concentration found in the Israeli DSW. Calcite content reduction was low (<1%) along the variably-saturated profile, after 50 years of MAR. This suggests that using soil-aquifer-treatment as a remineralization technique for DSW is potentially a sustainable practice, which is limited only by the current hydraulic capacity of the Menashe MAR site.
Artificial recharge of groundwater and its role in water management
Kimrey, J.O.
1989-01-01
This paper summarizes and discusses the various aspects and methods of artificial recharge with particular emphasis on its uses and potential role in water management in the Arabian Gulf region. Artificial recharge occurs when man's activities cause more water to enter an aquifer, either under pumping or non-pumping conditions, than otherwise would enter the aquifer. Use of artificial recharge can be a practical means of dealing with problems of overdraft of groundwater. Methods of artificial recharge may be grouped under two broad types: (a) water spreading techniques, and (b) well-injection techniques. Successful use of artificial recharge requires a thorough knowledge of the physical and chemical characteristics of the aquifier system, and extensive onsite experimentation and tailoring of the artificial-recharge technique to fit the local or areal conditions. In general, water spreading techniques are less expensive than well injection and large quantities of water can be handled. Water spreading can also result in significant improvement in quality of recharge waters during infiltration and movement through the unsaturated zone and the receiving aquifer. In comparison, well-injection techniques are often used for emplacement of fresh recharge water into saline aquifer zones to form a manageable lens of fresher water, which may later be partially withdrawn for use or continue to be maintained as a barrier against salt-water encroachment. A major advantage in use of groundwater is its availability, on demand to wells, from a natural storage reservoir that is relatively safe from pollution and from damage by sabotage or other hostile action. However, fresh groundwater occurs only in limited quantities in most of the Arabian Gulf region; also, it is heavily overdrafted in many areas, and receives very little natural recharge. Good use could be made of artificial recharge by well injection in replenishing and managing aquifers in strategic locations if sources of
Külls, Christoph; Nunes, Alice; Köbel-Batista, Melanie; Branquinho, Cristina; Bianconi, Nadja; Costantini, Eduardo
2014-05-01
Measures for monitoring desertification and soil degradation require a thorough understanding of soil physical properties and of the water balance in order to guide restoration efforts (Costantini et al. 2009). It is hypothesized that long term restoration success on degraded land depends on a series of interacting factors such as exposition, soil type, soil hydrology including lateral flow on hill-slope catenae. Recently, new soil water isotope measurement techniques have been developed (Garvelmann et al. 2012) that provide much faster and reliable stable water isotope profiles in soils. This technique yield information on groundwater recharge, soil water balance and on the origin of water available for plants, which in combination with conservative chemical tracers (chloride) can be validated. A multidisciplinary study including ecologists, soil physicists and hydrologists of the COST Action Desert Restoration Hub was carried out on four semi-arid sites in Portugal. A comparative characterization of soil physical parameters, soil water isotope and chloride profiles was performed in order to estimate pedoclimate, soil aridity, soil water balance and groundwater recharge. In combination with soil physical data a comprehensive and cross-validated characterization of pedoclimate and soil aridity was obtained. These indicators were then integrated and related to plant cover. The long-term rainfall of the four sites ranges from 512 to 638 mm, whereas air temperature is from 15.8 to 17.0°C. The De Martonne index of aridity spans from 19.3 to 24.6, pointing to semiarid to moderately arid climatic conditions. The long-term average number of days when the first 0.50 m of soil is dry ranges from 110 to 134, while the mean annual soil temperature at 0.50 m spans from 15.8 and 19.1°C. The studied profiles show different hydrological characteristics, in particular, the estimated hydraulic conductivity ranges from 0.1-1 to 10-100 µm/s. Three out of four profiles show a
Geochemical and Isotopic Characteristics of Quaternary Aquifer in Sohag District, Upper Egypt
International Nuclear Information System (INIS)
Ahmed, M.A.
2008-01-01
Thc Nile River valley represent one of the most important regions for agriculture and land reclamation in our area. Environmental isotopes and hydrochemical compositions in conjunction with geological and hydrogeological data were used to define chemical characteristics, sources of salinity, ground water origin and the possible recharge sources to the Nile Valley aquifer in Sohag district, Upper Egypt. The total dissolved solids of the ground water samples have higher values (445-7828 mg/L) than surface water (291-348 mg/L). The ground water in the Nile flood plain is very similar to that of the river water except at the margins of the basin. This ground water contains isotopic contents comparable to the river Nile with low TDS. The change of water quality at the old alluvium plain could be due to extensive use of fertilizers to improve soil characteristics in new reclamation area. Mineral saturation indices suggest that the dissolution of evaporites and halite is significant in the ground water and responsible for most of the ground water salinization. The relationships between Na + ,Cl - , Ca 2+ , Mg 2+ ,HCO 3 - and SO 4 2- show that complex geochemical processes control the chemical history of ground water: (I) continuous dissolution of evaporites and halite and precipitation of carbonate rocks, (2) cation exchange between ground water and clay minerals, (3) excessive use of fertilizers rich in MgSO 4 in the reclamation projects. The isotopic contents of surface water raged from 2.03 to 2.93%0 for δ 18 O, from 15.3 to 28.4%0 for δ 3 H, and from 4.6 to 7.8 TU for tritium while the isotopic contents of ground water ranged from -8,41 to 3,86% o for δ 18 O, from -67.8 to 29.9%0 for δ 2 H, and from 0.5 to 11.3 TU for tritium. The isotopic data reveals that the rechargability of this water is attributed to Nile flood water which was depleted in its isotopic content. Significant contribution from the palaeowater, which stored in the Nubia sandstone aquifer system
International Nuclear Information System (INIS)
Müller, Th.; Osenbrück, K.; Strauch, G.; Pavetich, S.; Al-Mashaikhi, K.-S.; Herb, C.; Merchel, S.; Rugel, G.; Aeschbach, W.; Sanford, W.
2016-01-01
Multiple age tracers were measured to estimate groundwater residence times in the regional aquifer system underlying southwestern Oman. This area, known as the Najd, is one of the most arid areas in the world and is planned to be the main agricultural center of the Sultanate of Oman in the near future. The three isotopic age tracers "4He, "1"4C and "3"6Cl were measured in waters collected from wells along a line that extended roughly from the Dhofar Mountains near the Arabian Sea northward 400 km into the Empty Quarter of the Arabian Peninsula. The wells sampled were mostly open to the Umm Er Radhuma confined aquifer, although, some were completed in the mostly unconfined Rus aquifer. The combined results from the three tracers indicate the age of the confined groundwater is 100 ka in the central section north of the mountains, and up to and > one Ma in the Empty Quarter. The "1"4C data were used to help calibrate the "4He and "3"6Cl data. Mixing models suggest that long open boreholes north of the mountains compromise "1"4C-only interpretations there, in contrast to "4He and "3"6Cl calculations that are less sensitive to borehole mixing. Thus, only the latter two tracers from these more distant wells were considered reliable. In addition to the age tracers, δ"2H and δ"1"8O data suggest that seasonal monsoon and infrequent tropical cyclones are both substantial contributors to the recharge. The study highlights the advantages of using multiple chemical and isotopic data when estimating groundwater travel times and recharge rates, and differentiating recharge mechanisms. - Highlights: • Multiple age tracers are required for the interpretation of the groundwater system. • Different tracers are applicable along different sections of the flowpath. • Groundwater residence times >1 Ma have been determined for the northern Najd area.
International Nuclear Information System (INIS)
Tan, Hongbing; Zhang, Yanfei; Zhang, Wenjie; Kong, Na; Zhang, Qing; Huang, Jingzhong
2014-01-01
Highlights: • Unique geothermal resources in Tibetan Plateau were discussed. • Isotopes were used to trace circulation of geothermal water. • Magmatic water mixing dominates geothermal water evolution. - Abstract: With the uplift of the Tibetan Plateau, many of the world’s rarest and most unique geothermal fields have been developed. This study aims to systematically analyze the characteristics of the hydrogen and oxygen isotopic data of geothermal, river, and lake waters to understand the circulation of groundwater and to uncover the mechanism of geothermal formation in the Tibetan Plateau. Field observations and isotopic data show that geothermal water has higher temperatures and hydraulic pressures, as well as more depleted D and 18 O isotopic compositions than river and lake waters. Thus, neither lakes nor those larger river waters are the recharge source of geothermal water. Snow-melt water in high mountains can vertically infiltrate and deeply circulate along some stretching tensile active tectonic belts or sutures and recharge geothermal water. After deep circulation, cold surface water evolves into high-temperature thermal water and is then discharged as springs at the surface again in a low area, under high water-head difference and cold–hot water density difference. Therefore, the large-scale, high-temperature, high-hydraulic-pressure geothermal systems in the Tibetan Plateau are developed and maintained by rapid groundwater circulation and the heat source of upwelled residual magmatic water. Inevitably, the amount of geothermal water will increase if global warming accelerates the melting of glaciers in high mountains
Stamos, Christina L.; Martin, Peter; Everett, Rhett; Izbicki, John A.
2013-01-01
recharge ponds in the middle of site 3, and YVUZ-2 was located approximately 1,200 feet down-gradient and to the southeast in an area where septic systems have been in use since about 1960. Site YVUZ-3 only went to a depth of 42 feet and was used to sample the upper part of the unsaturated zone near a golf course. Prior to the start of artificial recharge at site 3, nitrate concentrations reported as nitrogen from the soil leachate below YVUZ-1 did not exceed 1.58 milligrams per kilogram. Nitrate-reducing bacteria concentrations of 4,300 most probable number were found at about 220 feet below land surface and at the top of the water table at YVUZ-1. Nitrate concentrations at YVUZ-2 reached a maximum concentration of about 25 milligrams per kilogram between about 100 and 121 feet below land surface; concentrations of nitrate-reducing or denitrifying bacteria were as high as 21,000 most probable number at 36 feet below land surface but did not exceed 40 most probable number below about 150 feet below land surface. Between June 2006 and September 2009, more than 9,800 acre feet of water from the State Water Project was released to site 3 ponds. The infiltration of the recharge water was predominantly vertical with limited lateral spreading to a depth of about 200 feet below land surface at YVUZ-1. Lateral spreading of the recharge water with depth was caused by geologic heterogeneities within the unsaturated zone, and resulted in varied arrival times of the recharge water to the instruments and slower rates of vertical movement with depth. No abrupt changes in soil moisture were observed at YVUZ-2, indicating that the recharge water had not reached that site by September 2009. Water levels from the monitoring wells at both sites and from five production wells nearby showed that the water table rose at a mean rate of about 0.08 feet per day between June 2006 and January 2009. The arrival of the water from the State Water Project caused relatively rapid changes in the stable-isotopic
Synopsis of oxygen isotopes in geothermal solids and fluids of New Zealand
International Nuclear Information System (INIS)
Blattner, P.
1982-01-01
Geothermal minerals serve as downhole probes of oxygen isotope compositions and thus of parameters of geothermal hydrology. ''Deep'' wells (2500 m) in New Zealand show no sign of Δ 18 O values ''bottoming out''. Ngawha differs from other systems both in the level and profile details of Δ 18 O values. The reservoir fluid at Ngawha hydrogeology may or may not be suited for development of a high-throughput surface recharge system
Surma, J; Assonov, S; Herwartz, D; Voigt, C; Staubwasser, M
2018-03-21
This study demonstrates the potential of triple O-isotopes to quantify evaporation with recharge on a salt lake from the Atacama Desert, Chile. An evaporative gradient was found in shallow ponds along a subsurface flow-path from a groundwater source. Total dissolved solids (TDS) increased by 177 g/l along with an increase in δ 18 O by 16.2‰ and in δD by 65‰. 17 O-excess decreased by 79 per meg, d-excess by 55‰. Relative humidity (h), evaporation over inflow (E/I), the isotopic composition of vapor ( * R V ) and of inflowing water ( * R WI ) determine the isotope distribution in 17 O-excess over δ 18 O along a well-defined evaporation curve as the classic Craig-Gordon model predicts. A complementary on-site simple (pan) evaporation experiment over a change in TDS, δ 18 O, and 17 O-excess by 392 g/l, 25.0‰, and -130 per meg, respectively, was used to determine the effects of sluggish brine evaporation and of wind turbulence. These effects translate to uncertainty in E/I rather than h. The local composition of * R V relative to * R WI pre-determines the general ability to resolve changes in h. The triple O-isotope system is useful for quantitative hydrological balancing of lakes and for paleo-humidity reconstruction, particularly if complemented by D/H analysis.
Radioecological aspects in artificial groundwater recharge
Energy Technology Data Exchange (ETDEWEB)
Matthess, G [Kiel Univ. (Germany, F.R.). Geologisch-Palaeontologisches Inst. und Museum; Neumayr, V [Institut fuer Wasser-, Boden- und Lufthygiene, Frankfurt am Main (Germany, F.R.)
1980-01-01
In increasing extent surface waters, especially those of rivers and streams, are contaminated by radionuclides. Therefore it is necessary to investigate the possibility of impairment of the quality of artificially recharged groundwater and drinking water by radionuclides. Hazards for man are possible by drinking water, that was affected by waste and during exposition to air, as well as indirectly by irrigation water and the food chain. In a model calculation using realistic conditions the order of magnitude of these hazards for man by incorporation of radioactively contaminated artificially recharged drinking water are to be assessed. Here the parameters are discussed which must be considered in such an assessment. The model includes the use of river water for artificial recharge. All models and assessments assume the most unfavourable preconditions, which may lead to an impact to man.
International Nuclear Information System (INIS)
Onhon, E.
1983-08-01
Detailed field investigations with environmental isotopes (O-18, D, T, C-14 and C-13) have been conducted to study the replenishment process and flow dynamics of groundwater system in Edremit plain, which is an area of 200 m 2 size located in the eastern part of Turkey. Along with conventional hydrogeological and hydrochemical data collected from the study area, results of environmental isotopic analyses performed on water samples systematically collected from the area, enabled to delineate the source and origin of recharge to the shallow groundwater aquifers and as well provided information on various dynamic parameters of groundwater flow. In addition to basic flow dynamic characteristics of the shallow aquifer in the study area, environmental isotopes were used to investigate the hydraulic interconnections between deeper thermal groundwater system and the upper shallow aquifers. Results of all the environmental isotopic analyses and their interpretation are given
Stable isotope study of ground water recharge and movement in the Shogawa Fan, Toyama
International Nuclear Information System (INIS)
Mizutani, Yoshihiko; Oda, Matsuhisa
1983-01-01
Deuterium and oxygen-18 measurements of ground and river waters of the Shogawa Fan, Toyama, have been used to identify sources of water in aquifers in the Fan. A significant difference exists in deltaD and delta 18 O values between two major rivers flowing onto the Fan. On the basis of this difference, it is indicated that aquifers in the eastern half of the Fan are recharged from the Sho River and those in the western half of the Fan are from the Oyabe River. Chloride measurements of the waters support this identification of water sources. Contributions of other water sources to the aquifers are also indicated. The flow rate of infiltration from the Sho River is estimated to be 10-13 m/day in the confined aquifers in the northern part of the Fan. (author)
Comparing potential recharge estimates from three Land Surface Models across the Western US
NIRAULA, REWATI; MEIXNER, THOMAS; AJAMI, HOORI; RODELL, MATTHEW; GOCHIS, DAVID; CASTRO, CHRISTOPHER L.
2018-01-01
Groundwater is a major source of water in the western US. However, there are limited recharge estimates available in this region due to the complexity of recharge processes and the challenge of direct observations. Land surface Models (LSMs) could be a valuable tool for estimating current recharge and projecting changes due to future climate change. In this study, simulations of three LSMs (Noah, Mosaic and VIC) obtained from the North American Land Data Assimilation System (NLDAS-2) are used to estimate potential recharge in the western US. Modeled recharge was compared with published recharge estimates for several aquifers in the region. Annual recharge to precipitation ratios across the study basins varied from 0.01–15% for Mosaic, 3.2–42% for Noah, and 6.7–31.8% for VIC simulations. Mosaic consistently underestimates recharge across all basins. Noah captures recharge reasonably well in wetter basins, but overestimates it in drier basins. VIC slightly overestimates recharge in drier basins and slightly underestimates it for wetter basins. While the average annual recharge values vary among the models, the models were consistent in identifying high and low recharge areas in the region. Models agree in seasonality of recharge occurring dominantly during the spring across the region. Overall, our results highlight that LSMs have the potential to capture the spatial and temporal patterns as well as seasonality of recharge at large scales. Therefore, LSMs (specifically VIC and Noah) can be used as a tool for estimating future recharge rates in data limited regions. PMID:29618845
Impacts of vegetation change on groundwater recharge
Bond, W. J.; Verburg, K.; Smith, C. J.
2003-12-01
Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.
Kristensen, Emil; Madsen-Østerbye, Mikkel; Massicotte, Philippe; Pedersen, Ole; Markager, Stiig; Kragh, Theis
2018-02-01
Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5-45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only), total nitrogen (TN, lake only), total dissolved phosphorus (TDP, groundwater only), total phosphorus (TP, lake only), δ18O / δ16O isotope ratios and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS). The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs) of the lake (0.25-3.5 years in 0.25-year increments). These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration, the CATS model isolated
Isotope study of groundwater in Beishan area, Gansu province
International Nuclear Information System (INIS)
Guo Yonghai; Liu Shufen; Yang Tianxiao
2004-01-01
Using the isotope techniques, the groundwater origin, evolution and circulation in the potential site of China's high-level waste repository are studied. The results indicate that both shallow groundwaters are and deep groundwaters in the site area are of meteoric origin. The shallow groundwaters are mainly recharged by modern and local precipitation, and the deep groundwaters are originated from regional history period with lower temperature. Through the study we can also understand that the deep underground is a very low-permeability system where the groundwater flow-rates are very low. (author)
Managed Aquifer Recharge in Italy: present and prospects.
Rossetto, Rudy
2015-04-01
On October the 3rd 2014, a one-day Workshop on Managed Aquifer Recharge (MAR) experiences in Italy took place at the GEOFLUID fair in Piacenza. It was organized within the framework of the EIP AG 128 - MAR Solutions - Managed Aquifer Recharge Strategies and Actions and the EU FPVII MARSOL. The event aimed at showcasing present experiences on MAR in Italy while at the same time starting a network among all the Institutions involved. In this contribution, we discuss the state of MAR application in Italy and summarize the outcomes of that event. In Italy aquifer recharge is traditionally applied unintentionally, by increasing riverbank filtration or because of excess irrigation. A certain interest for artificial recharge of aquifers arose at the end of the '70s and the beginning of the '80s and tests have been carried out in Tuscany, Veneto and Friuli Venezia Giulia. During the last years some projects on aquifer recharge were co-financed by the European Commission mainly through the LIFE program. Nearly all of them use the terminology of artificial recharge instead of MAR. They are: - TRUST (Tool for regional - scale assessment of groundwater storage improvement in adaptation to climate change, LIFE07 ENV/IT/000475; Marsala 2014); - AQUOR (Implementation of a water saving and artificial recharging participated strategy for the quantitative groundwater layer rebalance of the upper Vicenza's plain - LIFE 2010 ENV/IT/380; Mezzalira et al. 2014); - WARBO (Water re-born - artificial recharge: innovative technologies for the sustainable management of water resources, LIFE10 ENV/IT/000394; 2014). While the TRUST project dealt in general with aquifer recharge, AQUOR and WARBO focused essentially on small scale demonstration plants. Within the EU FPVII-ENV-2013 MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought; 2014), a dedicated monitoring and decision support system is under development to manage recharge at a large scale
Advances of aqueous rechargeable lithium-ion battery: A review
Alias, Nurhaswani; Mohamad, Ahmad Azmin
2015-01-01
The electrochemical characteristic of the aqueous rechargeable lithium-ion battery has been widely investigated in efforts to design a green and safe technology that can provide a highly specific capacity, high efficiency and long life for high power applications such as the smart grid and electric vehicle. It is believed that the advantages of this battery will overcome the limitations of the rechargeable lithium-ion battery with organic electrolytes that comprise safety and create high fabrication cost issues. This review focuses on the opportunities of the aqueous rechargeable lithium-ion battery compared to the conventional rechargeable lithium-ion battery with organic-based electrolytes. Previously reported studies are briefly summarised, together with the presentation of new findings based on the conductivity, morphology, electrochemical performance and cycling stability results. The factors that influence the electrochemical performance, the challenges and potential of the aqueous rechargeable lithium-ion battery are highlighted in order to understand and maintained the excellent battery performance.
Isotope hydrology study of Molai area in Laconia
International Nuclear Information System (INIS)
Leontiadis, J.L.
1981-04-01
The isotopic composition of the groundwater was used in order to investigate the mechanism of recharge of the Molai plain (Laconia) and of the coastal brackish springs of the area. The results of this study have shown that the Tripolitza carbonates, northeast of the plain, do not form a unique aquifer nor contribute to the recharge of the plain which is mainly fed by the local rainwater. The brackish springs at Glyfada are fed by the Tripolitza carbonates, northeast of the Mavrovouni-Koupia fault, through an isolated from the neogene aquifer of the plain conduit. The water content of the corresponding reservoir is estimated in the range of 2318 to 3091 hm 3 . The brackish springs at Plytra are fed by the marbles of Chavallas and Skardolakka mountains through the bedrock of Assopos river and the neogene aquifer of that part of the plain. The water content of the corresponding reservoir is estimated to be more than 284 hm 3 . The brackish coastal springs between Palea Monemvasia and Hierax are fed by the Tripolitza limestones southeast of the Mavrovouni-Koupia fault. (T.A.)
Groundwater Modelling For Recharge Estimation Using Satellite Based Evapotranspiration
Soheili, Mahmoud; (Tom) Rientjes, T. H. M.; (Christiaan) van der Tol, C.
2017-04-01
Groundwater movement is influenced by several factors and processes in the hydrological cycle, from which, recharge is of high relevance. Since the amount of aquifer extractable water directly relates to the recharge amount, estimation of recharge is a perquisite of groundwater resources management. Recharge is highly affected by water loss mechanisms the major of which is actual evapotranspiration (ETa). It is, therefore, essential to have detailed assessment of ETa impact on groundwater recharge. The objective of this study was to evaluate how recharge was affected when satellite-based evapotranspiration was used instead of in-situ based ETa in the Salland area, the Netherlands. The Methodology for Interactive Planning for Water Management (MIPWA) model setup which includes a groundwater model for the northern part of the Netherlands was used for recharge estimation. The Surface Energy Balance Algorithm for Land (SEBAL) based actual evapotranspiration maps from Waterschap Groot Salland were also used. Comparison of SEBAL based ETa estimates with in-situ abased estimates in the Netherlands showed that these SEBAL estimates were not reliable. As such results could not serve for calibrating root zone parameters in the CAPSIM model. The annual cumulative ETa map produced by the model showed that the maximum amount of evapotranspiration occurs in mixed forest areas in the northeast and a portion of central parts. Estimates ranged from 579 mm to a minimum of 0 mm in the highest elevated areas with woody vegetation in the southeast of the region. Variations in mean seasonal hydraulic head and groundwater level for each layer showed that the hydraulic gradient follows elevation in the Salland area from southeast (maximum) to northwest (minimum) of the region which depicts the groundwater flow direction. The mean seasonal water balance in CAPSIM part was evaluated to represent recharge estimation in the first layer. The highest recharge estimated flux was for autumn
International Nuclear Information System (INIS)
Jacob, Noble
2017-01-01
The groundwater potential of Anjangaon village in Amaravati district of Maharashtra is generally poor and the water quality is saline in most of the places. Farmers dig open wells (up to 30 m depth) and drill bore wells (100-150 m depth) for domestic and irrigation purposes. Most of the wells failed and farmers are struggling for fresh water in this region. To evaluate the groundwater recharge and to identify the groundwater potential zones an environmental isotope and geophysical study was carried out. Water samples were collected from rain, springs, open wells, bore wells and detention tanks and measured for environmental isotopes such as "1"8O, "2H and "3H. Isotope results indicate that the groundwater is getting modern component of recharge from the rain as well as from the detention tanks. The percentage contributions from the detention tanks were estimated to be about 40 to 90 %. In the southern part of the Anjagaon village, an electrical resistivity survey of the geological formation was carried out and a groundwater potential zone was delineated at 45m depth. The farmers were asked to drill bore wells at the identified depth. The drilled five bore wells yielded perennial source of good quality water
International Nuclear Information System (INIS)
Panarello, H.O.
1990-01-01
Results and conclusions obtained under the framework of the 3995/RB research contract between the IAEA and the INGEIS with participation of the Dirreccion de Geologia, Mineria y Aguas Subterraneas (DGMAS) and the Centro Federal de Inversiones (C.F.I.) are presented. From the results the suitability of the isotope techniques for tracing hydrodynamic processes could be confirmed. Recharge condition also have been defined. The exceptional event of flood in the Buenos Aires province that begin in 1986 in connection with abnormal high precipitations targed infiltrating waters with the isotopical signal of the evaporation. This signal was found out in many of the sampled wells and allowed to recognize the recharge, even to significant depths. In the Pinamar and Villa Gesell towns, it was possible to establish the dynamic of wells under seasonal exploitation. In the most of cases water withdrawn in summer was recharged in the immediate precedent pluvious period. Refs, figs and tabs
International Nuclear Information System (INIS)
Vaniman, D.T.; Whelan, J.F.
1994-01-01
Past research has indicated a genetic connection between calcite formed in calcretes at the surface of Yucca Mountain, Nevada, and calcites deposited in underlying fractures of the unsaturated zone. This common genesis suggests that paleoenvironmental information, as well as the timing and pathways of past recharge episodes, might be obtained from studies of the deposits in both the calcretes and the unsaturated fractures. Chemical and isotopic modification of calcite-precipitating fluids appears to begin at the surface, largely under the influence of plant roots and their decay products. Chemical characteristics of the deeper calcites are either initiated or largely defined within the first few meters of fluid migration into the unsaturated tuffs beneath the calcretes. However, petrographic and isotopic data indicate a very unique low-δ 13 C microenvironment that is localized at the upper surfaces of the calcretes. These surfaces form an interface in the soil horizon where infiltration may pond above the underlying carbonate ''plug.'' In order to decipher the chemistry and petrology of past recharge events, it is important to first understand microenvironments such as this that contribute to mineral precipitation/dissolution events in the pedogenic environment
Implications of projected climate change for groundwater recharge in the western United States
Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David J.; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle A.
2016-03-01
Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10-20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed
Implications of projected climate change for groundwater recharge in the western United States
Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle Ann
2016-01-01
Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10–20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using
Wang, Liheng; Dong, Yanhui; Xu, Zhifang; Qiao, Xiaojuan
2017-12-01
Groundwater is typically the only water source in arid regions, and its circulation processes should be better understood for rational resource exploitation. Stable isotopes and major ions were investigated in the northeastern Tengger Desert, northern China, to gain insights into groundwater recharge and evolution. In the northern mountains, Quaternary unconsolidated sediments, exposed only in valleys between hills, form the main aquifer, which is mainly made of aeolian sand and gravel. Most of the mountain groundwater samples plot along the local meteoric water line (LMWL), with a more depleted signature compared to summer precipitation, suggesting that mountain groundwater was recharged by local precipitation during winter. Most of the groundwater was fresh, with total dissolved solids less than 1 g/L; dominant ions are Na+, SO4 2- and Cl-, and all mineral saturation indices are less than zero. Evaporation, dissolution and cation exchange are the major hydrogeochemical processes. In the southern plains, however, the main aquifers are sandstone. The linear regression line of δD and δ 18O of groundwater parallels the LMWL but the intercept is lower, indicating that groundwater in the plains has been recharged by ancient precipitation rather than modern. Both calcite and dolomite phases in the plains groundwater are close to saturation, while gypsum and halite can still be dissolved into the groundwater. Different recharge mechanisms occur in the northern mountains and the southern plains, and the hydraulic connection between them is weak. Because of the limited recharge, groundwater exploitation should be limited as much as possible.
Flint, Lorraine E.; Brandt, Justin; Christensen, Allen H.; Flint, Alan L.; Hevesi, Joseph A.; Jachens, Robert; Kulongoski, Justin T.; Martin, Peter; Sneed, Michelle
2012-01-01
Big Bear Valley. The INFILv3 model was modified for this study to include a perched zone beneath the root zone to better simulate lateral seepage and recharge in the shallow subsurface in mountainous terrain. The climate input used in the INFILv3 model was developed by using daily climate data from 84 National Climatic Data Center stations and published Parameter Regression on Independent Slopes Model (PRISM) average monthly precipitation maps to match the drier average monthly precipitation measured in the Baldwin Lake drainage basin. This model resulted in a good representation of localized rain-shadow effects and calibrated well to measured lake volumes at Big Bear and Baldwin Lakes. The simulated average annual recharge was about 5,480 acre-ft/yr in the Big Bear study area, with about 2,800 acre-ft/yr in the Big Bear Lake surface-water drainage basin and about 2,680 acre-ft/yr in the Baldwin Lake surface-water drainage basin. One spring and eight wells were sampled and analyzed for chemical and isotopic data in 2005 and 2006 to determine if isotopic techniques could be used to assess the sources and ages of groundwater in the Big Bear Valley. This approach showed that the predominant source of recharge to the Big Bear Valley is winter precipitation falling on the surrounding mountains. The tritium and uncorrected carbon-14 ages of samples collected from wells for this study indicated that the groundwater basin contains water of different ages, ranging from modern to about 17,200-years old.The results of these investigations provide an understanding of the lateral and vertical extent of the groundwater basin, the spatial distribution of groundwater recharge, the processes responsible for the recharge, and the source and age of groundwater in the groundwater basin. Although the studies do not provide an understanding of the detailed water-bearing properties necessary to determine the groundwater availability of the basin, they do provide a framework for the future
Using groundwater levels to estimate recharge
Healy, R.W.; Cook, P.G.
2002-01-01
Accurate estimation of groundwater recharge is extremely important for proper management of groundwater systems. Many different approaches exist for estimating recharge. This paper presents a review of methods that are based on groundwater-level data. The water-table fluctuation method may be the most widely used technique for estimating recharge; it requires knowledge of specific yield and changes in water levels over time. Advantages of this approach include its simplicity and an insensitivity to the mechanism by which water moves through the unsaturated zone. Uncertainty in estimates generated by this method relate to the limited accuracy with which specific yield can be determined and to the extent to which assumptions inherent in the method are valid. Other methods that use water levels (mostly based on the Darcy equation) are also described. The theory underlying the methods is explained. Examples from the literature are used to illustrate applications of the different methods.
International Nuclear Information System (INIS)
Dapena, C.; Panarello, H.O.
2007-01-01
The isotopic composition of precipitation in Buenos Aires station is of great importance to understand the Pampean hydrological Systems. The rain isotope content ( 2 H, 18 O and 3 H) is being recorded since 1978 at Ciudad Universitaria Station, belonging to the Red Nacional de Colectores constitutes the main recharge factor for most of local and regional hydrologic system. The knowledge and characterization of their isotope content is of fundamental importance for a hydrological investigation, so we need a historical updated record. For this reason the International Atomic Energy Agency (IAEA) in co-operation with the World Meteorological Organization (WMO) developed an international network devoted to the measurement of isotope contents in precipitation named as GNIP (Global Network for Isotopes in Precipitation) which started in 1960. The main objective of the network is to evaluate on a global scale the spatial and temporal distribution of isotope contents in precipitation and their dependence to relevant meteorological parameters. In this framework, the 'Instituto de Geocronologia y Geologia Isotopica' (INGEIS) established a National Collector Network for Isotopes in Precipitation (RNC) which integrates with the GNIP. The operation of the network in Argentina began in November 1978 with one station located in Buenos Aires City. At present, INGEIS is operating 17 stations at different altitudes and latitudes, covering a wide range of temperatures and a large variety of climates. This information allows us to know the input functions (rain isotope content) at different regions of the country. Signatures of isotopes in precipitation are not static. They respond to both, synoptic and climatology and global climate change. Attracted by this issue, a new community, interested in palaeoclimate and atmospheric circulation modelling, started to use the GNIP data. However, it becomes apparent soon that the collected data were also useful in other water-related fields
International Nuclear Information System (INIS)
Sood, S.K.; Fong, C.
1997-05-01
The design review performed on the ITER Isotope Separation System and the Water Detritiation System are summarized. The objectives of the task are: to produce a Design Description Document for the Feed Treatment and Vacuum system for the Water Detritiation system; to review the process system operation and control philosophy for the Water Detritiation System; to review the equipment arrangement drawings where available. 1 fig., 3 refs
International Nuclear Information System (INIS)
Carreira, P.M.; Nunes, D.; Marques, J.M.; Pina, A.; Mota Gomes, A.; Almeida, E.; Goncalves, R.; Monteiro Santos, F.
2007-01-01
Two sampling campaigns were carried out at Santiago Island - Cabo Verde under the scope of an isotopic and geochemical research study. An evaluation of the groundwater systems was carried out through the application of environmental isotopes and geochemical data in order to answer questions such as: origin and mechanisms of groundwater recharge; relation between the hydrochemical evolution of the groundwater systems with the geological matrix (minerals dissolution) or mixture with seawater and aerosol marine influence; identification of seawater intrusion mechanisms and, determination of the apparent groundwater 'age'. The results obtained so far are not conclusive on the identification of the process responsible for the increase of salinity. In general, all the data obtained seems to indicate that the waters have the same isotopic history but different geochemical evolution, which depends on the weathering and permeability of the rocks. (author)
The aquifer recharge: an overview of the legislative and planning aspect.
De Giglio, O; Caggiano, G; Apollonio, F; Marzella, A; Brigida, S; Ranieri, E; Lucentini, L; Uricchio, V F; Montagna, M T
2018-01-01
In most regions of the world, safeguarding groundwater resources is a serious issue, particularly in coastal areas where groundwater is the main water source for drinking, irrigation and industry. Water availability depends on climate, topography and geology. The aim of this paper is to evaluate aquifer recharge as a possible strategy to relieve water resource scarcity. Natural aquifer recharge is defined as the downward flow of water reaching the water table, increasing the groundwater reservoir. Hydro-meteorological factors (rainfall, evapotranspiration and runoff) may alter natural recharge processes. Artificial aquifer recharge is a process by which surface water is introduced with artificial systems underground to fill an aquifer. As a consequence of global warming that has increased the frequency and severity of natural disasters like the drought, the impacts of climate change and seasonality, the artificial recharge has been considered as a viable option. Different direct and indirect techniques can be used, and the choice depends on the hydrologic characteristics of a specific area. In Italy, Legislative Decree no. 152/06 plans artificial aquifer recharge as an additional measure in water management, and Decree no. 100/2016 establishes quantitative and qualitative conditions for recharge. Many projects examine aquifer recharge, such us WADIS-MAR in the southern Mediterranean region, WARBO in Italy and municipal wastewater treatment project in Apulia, a southern Italian region. However, aside from groundwater recharge, the community must foster a spirit of cooperation to manage groundwater as a sustainable resource.
Energy Technology Data Exchange (ETDEWEB)
Minissale, A., E-mail: minissa@igg.cnr.it [CNR - Italian Council for Research, Institute of Geosciences and Earth Resources (Section of Florence) - Via La Pira 4, 50121 Firenze (Italy); Vaselli, O. [CNR - Italian Council for Research, Institute of Geosciences and Earth Resources (Section of Florence) - Via La Pira 4, 50121 Firenze (Italy)] [Department of Earth Sciences, University of Florence - Via La Pira 4, 50121 Firenze (Italy)
2011-05-15
Highlights: > Isotopic compositions of karstic springs in central Italy have been reviewed. > Isotopic gradients of rainfalls for elevations have been evaluated in an Alpine valley. > Karstic drops have been calculated by using isotopic compositions of springs. > Isotopic compositions of rainfalls in central Italy have been re-calculated using the isotopic compositions of karstic springs. - Abstract: This paper describes an indirect method to calculate the isotopic composition of rainfall by using the isotopic composition of karst springs fed by waters circulating in the most important regional aquifer of central Italy, i.e. the Mesozoic limestone sequence that forms the backbone of the Apennines. By using {delta}{sup 18}O and {delta}D data and the {delta}{sup 18}O (and/or {delta}D) average gradient for elevation, evaluated through the use of literature rainfall data and new measurements from a typical Alpine valley in northern Italy, the altitude of precipitation of their parent water has been re-calculated. Vertical descents of more than 2000 m, from recharge to discharge, have been assessed in some high flow-rate cold springs in the morphologically steep Adriatic sector of central Italy. A clear correlation between the vertical descents and more negative isotopic compositions at their relative emergence elevations is highlighted. In contrast, in the Tyrrhenian sector lower karstic drops (generally lower than 500 m) correlate with less negative isotopic composition of recharge areas. The {delta}{sup 18}O iso-contour map of the 'recalculated' parent rainfall in central Italy is more detailed than any possible isotopic map of rainfall made using pluviometers, unless large number of rainfall collectors were deployed on mountaintops. The data also show that the isotopic composition of rainfall depends on the source of the storm water. In particular, precipitation is isotopically heavier when originating in the Mediterranean Sea, and lighter when formed in
Transformer Recharging with Alpha Channeling in Tokamaks
International Nuclear Information System (INIS)
Fisch, N.J.
2009-01-01
Transformer recharging with lower hybrid waves in tokamaks can give low average auxiliary power if the resistivity is kept high enough during the radio frequency (rf) recharging stage. At the same time, operation in the hot ion mode via alpha channeling increases the effective fusion reactivity. This paper will address the extent to which these two large cost saving steps are compatible.
Precipitation Intensity Effects on Groundwater Recharge in the Southwestern United States
Directory of Open Access Journals (Sweden)
Brian F. Thomas
2016-03-01
Full Text Available Episodic recharge as a result of infrequent, high intensity precipitation events comprises the bulk of groundwater recharge in arid environments. Climate change and shifts in precipitation intensity will affect groundwater continuity, thus altering groundwater recharge. This study aims to identify changes in the ratio of groundwater recharge and precipitation, the R:P ratio, in the arid southwestern United States to characterize observed changes in groundwater recharge attributed to variations in precipitation intensity. Our precipitation metric, precipitation intensity magnification, was used to investigate the relationship between the R:P ratio and precipitation intensity. Our analysis identified significant changes in the R:P ratio concurrent with decreases in precipitation intensity. The results illustrate the importance of precipitation intensity in relation to groundwater recharge in arid regions and provide further insights for groundwater management in nonrenewable groundwater systems and in a changing climate.
30 CFR 57.4203 - Extinguisher recharging or replacement.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Extinguisher recharging or replacement. 57.4203 Section 57.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Prevention and Control Firefighting Equipment § 57.4203 Extinguisher recharging or replacement. Fire...
30 CFR 56.4203 - Extinguisher recharging or replacement.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Extinguisher recharging or replacement. 56.4203 Section 56.4203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Prevention and Control Firefighting Equipment § 56.4203 Extinguisher recharging or replacement. Fire...
Energy Technology Data Exchange (ETDEWEB)
Rodriguez-Arevalo, J.; Diaz-Teijeiro, M. F. [Centro de Estudios y Experimentacion de Obras Publicas (CEDEX), Madrid (Spain); Castano, S. [Geological Survey of Spain (IGME), Madrid (Spain)
2013-07-15
A simple multiple regression model based on two geographic factors (latitude and elevation) has been developed that reproduces reasonably well the spatial distribution of the current mean oxygen-18 isotope composition in precipitation over spain. In a preliminary analysis, additional geographic and climatic factors do not improve the performance of the model. A continuous digital map of oxygen-18 isotope composition in precipitation has been produced by combining the polynomial model with a digital elevation model using GIS tools. Application of the resulting map to several groundwater case studies in spain has shown it to be useful as a reference of the input function to recharge. Further validation of the model, and further testing of its usefulness in surface hydrology and climatic studies, is ongoing through comparison of model results with isotope data from the GNIP database and from isotope studies in hydrogeology and climate change taking place in spain. (author)
International Nuclear Information System (INIS)
Maduabuchi, C.
2000-07-01
This publication summarizes the result of the project on the use of isotope techniques for the study of recharge and discharge of the Sokoto-Rima hydrological basin in the semi-arid and northwestern part of Nigeria
Isotope hydrology of groundwaters in the Donana National Park and the associated zone of influence
International Nuclear Information System (INIS)
Plata, A.; Baonza, E.; Silgado, A.
1984-01-01
The authors describe a study, using environmental isotopes, of the groundwaters of a complex hydrological system formed by a free recharge zone with a multi-layer structure, a confined zone with connate waters trapped by the deposition of a thick clay layer in a coastal pool environment, and a series of both recent and ancient highly permeable dune formations. Attempts have been made, using tritium of thermonuclear origin, to determine the approximate average recharge rate during the last 28 years in the free aquifer zone. Despite the difficulties encountered, the value of 78 mm/a obtained, which is 13.2% of the average precipitation, is very similar to that obtained using conventional methods (approximately 84 mm/a). As was expected, there was no tritium in the confined zone. Carbon-14 was used to determine the reduced velocity of the underground stream and to confirm the network of streams deduced from conductivity measurements. The age-correction methods proposed by Tamers, Pearson, Mook and Fontes were compared. The differences in age between the last method and the first two are reasonable and can be explained by the isotopic interchange between the CaCO 3 of the rock formation and the gaseous CO 2 included in Fontes' model. On the other hand, the differences found with the Mook method are considerable, particularly for sample values below delta 13 C. The last model is more sensitive to changes in delta 13 C, and the interval of this parameter for which this model gives reasonable values of age is very small. In addition, the 14 C made it possible to determine the sedimentation velocity of clays in the swamp zone. The stable isotopes in the water confirmed the hypothesis that the underground waters in the confinement zone are a mixture of fresh water which has infiltrated into the recharge zone and of connate water trapped by the deposition of the clay layer. (author)
Kloppmann, Wolfram; Vengosh, Avner; Guerrot, Catherine; Millot, Romain; Pankratov, Irena
2008-07-01
A systematic measurement of ions and 2H/1H, 7Li/6Li, 11B/10B, 18O/ 16O, and 87Sr/86Sr isotopes in feed-waters, permeates, and brines from commercial reverse osmosis (RO) desalination plants in Israel (Ashkelon, Eilat, and Nitzana) and Cyprus (Larnaca) reveals distinctive geochemical and isotopic fingerprints of fresh water generated from desalination of seawater (SWRO) and brackish water (BWRO). The degree of isotope fractionation during the passage of water and solutes through the RO membranes depends on the medium (solvent-water vs. solutes), chemical speciation of the solutes, their charge, and their mass difference. O, H, and Sr isotopes are not fractionated during the RO process. 7Li is preferentially rejected in low pH RO, and B isotope fractionation depends on the pH conditions. Under low pH conditions, B isotopes are not significantly fractionated, whereas at high pH, RO permeates are enriched by 20 per thousand in 11B due to selective rejection of borate ion and preferential permeation of 11B-enriched boric acid through the membrane. The specific geochemical and isotopic fingerprints of SWRO provide a unique tool for tracing "man-made" fresh water as an emerging recharge component of natural water resources.
Management of ground water using isotope techniques
International Nuclear Information System (INIS)
Romani, Saleem
2004-01-01
Ground water play a major role in national economy and sustenance of life and environment. Prevalent water crisis in India includes falling water table, water quality deterioration, water logging and salinity. Keeping in view the increasing thrust on groundwater resources and the present scenario of availability vis-a vis demand there is a need to reorient our approach to ground water management. The various ground water management options require proper understanding of ground water flow system. Isotopes are increasingly being applied in hydrogeological investigations as a supplementary tool for assessment of aquifer flow and transport characteristics. Isotope techniques coupled with conventional hydrogeological and hydrochemical methods can bring in greater accuracy in the conceptualization of hydrogeological control mechanism. The use of isotope techniques in following areas can certainly be of immense help in implementing various ground water management options in an efficient manner. viz.Interaction between the surface water - groundwater systems to plan conjunctive use of surface and ground water. Establishing hydraulic interconnections between the aquifers in a multi aquifer system. Depth of circulation of water and dating of ground water. Demarcating ground water recharge and discharge areas. Plan ground water development in coastal aquifers to avoid sea water ingress. Development of flood plain aquifer. (author)
Recharge estimation in semi-arid karst catchments: Central West Bank, Palestine
Jebreen, Hassan; Wohnlich, Stefan; Wisotzky, Frank; Banning, Andre; Niedermayr, Andrea; Ghanem, Marwan
2018-03-01
Knowledge of groundwater recharge constitutes a valuable tool for sustainable management in karst systems. In this respect, a quantitative evaluation of groundwater recharge can be considered a pre-requisite for the optimal operation of groundwater resources systems, particular for semi-arid areas. This paper demonstrates the processes affecting recharge in Palestine aquifers. The Central Western Catchment is one of the main water supply sources in the West Bank. Quantification of potential recharge rates are estimated using chloride mass balance (CMB) and empirical recharge equations over the catchment. The results showing the spatialized recharge rate, which ranges from 111-216 mm/year, representing 19-37% of the long-term mean annual rainfall. Using Water Balance models and climatological data (e. g. solar radiation, monthly temperature, average monthly relative humidity and precipitation), actual evapotranspiration (AET) is estimated. The mean annual actual evapotranspiration was about 66-70% of precipitation.
Chloride-mass-balance for predicting increased recharge after land-use change
Energy Technology Data Exchange (ETDEWEB)
Gee, G.W.; Zhang, Z.F.; Tyler, S.W.; Albright, W.H.; Singleton, M.J.
2004-02-23
The chloride-mass-balance (CMB) method has been used extensively to estimate recharge in arid and semi-arid environments. Required data include estimates of annual precipitation, total chloride input (from dry fallout and precipitation), and pore-water chloride concentrations. Typically, CMB has been used to estimate ancient recharge but recharge from recent land-use change has also been documented. Recharge rates below a few mm/yr are reliably detected with CMB; however, estimates above a few mm/yr appear to be less reliable. We tested the CMB method against 26 years of drainage from a 7.6-m-deep lysimeter at a simulated waste-burial ground, located on the Department of Energy s Hanford Site in southeastern Washington State, USA where land-use change has increased recharge rates. Measured drainage from the lysimeter for the past 26 years averaged 62 mm/yr. Precipitation averaged 190 mm/yr with an estimated chloride input of 0.225 mg/L. Initial pore-water chloride concentration was 88 mg/L and decreased to about 6 mg/L after 26 years, while the drainage water decreased to less than 1 mg/L. A recharge estimate made using chloride concentrations in drain water was within 20 percent of the measured drainage rate. In contrast, recharge estimates using 1:1 (water: soil) extracts were lower than actual by factors ranging from 2 to 8 or more. The results suggest that when recharge is above a few mm/yr, soil water extracts can lead to unreliable estimates of recharge. For conditions of elevated recharge, direct sampling of pore water is the preferred method, because chloride concentrations are often 20 to 50 times higher in directly-sampled pore water than in pore-water extracts.
Zheng, G.; Cao, J. R.; Cheng, X. S.; Ha, D.; Wang, F. J.
2018-02-01
Artificial recharge measures have been adopted to control the drawdown of confined aquifers and the ground subsidence caused by dewatering during deep excavation in Tianjin, Shanghai and other regions in China. However, research on recharge theory is still limited. Additionally, confined aquifers consisting of silt and silty sand in Tianjin have lower hydraulic conductivities than those consisting of sand or gravel, and the feasibility and effectiveness of recharge methods in these semiconfined aquifers urgently require investigation. A series of single-well and multiwell pumping and recharge tests was conducted at a metro station excavation site in Tianjin. The test results showed that it was feasible to recharge silt and silty sand semiconfined aquifers, and, to a certain extent, the hydrogeological parameters obtained from the pumping tests could be used to predict the water level rise during single-well recharge. However, the predicted results underestimated the water level rise near the recharge well (within 7 m) by approximately 10-25%, likely because the permeability coefficient around the well was reduced during the recharge process. Pressured recharge significantly improved the efficiency of the recharge process. Maintaining the recharge and pumping rates at a nearly equal level effectively controlled the surrounding surface and building settlement. However, the surrounding surface subsidence tended to rapidly develop when recharge stopped. Therefore, the recharge process should continue and gradually stop after the pumping stops. The twin-well combined recharge technique can be used to control the head loss of an aquifer when one of the recharge wells requires pumping to solve the associated clogging problems.
Vengosh, A.; Hening, S.; Ganor, J.; Mayer, B.; Weyhenmeyer, C.E.; Bullen, T.D.; Paytan, A.
2007-01-01
The geochemistry and isotopic composition (H, O, S, Osulfate, C, Sr) of groundwater from the Nubian Sandstone (Kurnub Group) aquifer in the Negev, Israel, were investigated in an attempt to reconstruct the origin of the water and solutes, evaluate modes of water-rock interactions, and determine mean residence times of the water. The results indicate multiple recharge events into the Nubian sandstone aquifer characterized by distinctive isotope signatures and deuterium excess values. In the northeastern Negev, groundwater was identified with deuterium excess values of ???16???, which suggests local recharge via unconfined areas of the aquifer in the Negev anticline systems. The ??18OH2O and ??2H values (-6.5??? and -35.4???) of this groundwater are higher than those of groundwater in the Sinai Peninsula and southern Arava valley (-7.5??? and -48.3???) that likewise have lower deuterium excess values of ???10???. Based on the geochemical differences between groundwater in the unconfined and confined zones of the aquifer, a conceptual geochemical model for the evolution of the groundwater in the Nubian sandstone aquifer has been reconstructed. The isotopic composition of shallow groundwater from the unconfined zone indicates that during recharge oxidation of pyrite to SO4 (??34SSO4 ???-13???; ??18OSO4 ???+7.7???) and dissolution of CaCO3 (87Sr/86Sr ???0.70787; ??13CDIC = -3.7???) occur. In the confined zone of the aquifer, bacterial SO4 reduction removes a significant part of dissolved SO42 -, thereby modifying its isotopic composition (??34SSO4 ???-2???; ??18OSO4 ???+8.5???) and liberating dissolved inorganic C that contains little or no radiocarbon (14C-free) with low ??13CDIC values (contribution of external groundwater sources to the Nubian Sandstone aquifer, resulting in further modifications of the groundwater chemical and isotopic signatures. In the northeastern Negev, it is shown that SO4-rich groundwater from the underlying Jurassic aquifer contributes
International Nuclear Information System (INIS)
Abd El-Samie, S.G.; Sadek, M.A.; Mahmoud, N.S.
2002-01-01
The tenth of ramadan city is an intensive industrial settement on the peripheries of cairo. All types of wastewater from industrial and domestic practices are discharged into three unlined oxidation ponds to eliminate pollutants. The present srudy has been conduted to assess the extent of seepage to groundwater from the ponds and how efficient they are for pollution reduction. The chemical composition is more developed in the groundwater of the miocene aquifer due to the less active recharge and the dominance of readily dissolved salts that interact with the inflow. The seepage from ismailia canal and the excess irrigation from agricultural lands and the infiltration from the oxidation ponds as well as the upleaked water represent the main sources of recharge in the quaternary aquifer. The chemical and isotopic composition of the water in the oxidation ponds is controlled by the nature of the drained water and the geochemical processes affecting the solute content. The isotopic enrichment differs for the three ponds being related to the evaporation intensity in each
Understanding wetland sub-surface hydrology using geologic and isotopic signatures
Directory of Open Access Journals (Sweden)
P. Sahu
2009-07-01
Full Text Available This paper attempts to utilize hydrogeology and isotope composition of groundwater to understand the present hydrological processes prevalent in a freshwater wetland, source of wetland groundwater, surface water/groundwater interaction and mixing of groundwater of various depth zones in the aquifer. This study considers East Calcutta Wetlands (ECW – a freshwater peri-urban inland wetland ecosystem located at the lower part of the deltaic alluvial plain of South Bengal Basin and east of Kolkata city. This wetland is well known over the world for its resource recovery systems, developed by local people through ages, using wastewater of the city. Geological investigations reveal that the sub-surface geology is completely blanketed by the Quaternary sediments comprising a succession of silty clay, sand of various grades and sand mixed with occasional gravels and thin intercalations of silty clay. At few places the top silty clay layer is absent due to scouring action of past channels. In these areas sand is present throughout the geological column and the areas are vulnerable to groundwater pollution. Groundwater mainly flows from east to west and is being over-extracted to the tune of 65×103 m3/day. δ18O and δD values of shallow and deep groundwater are similar indicating resemblance in hydrostratigraphy and climate of the recharge areas. Groundwater originates mainly from monsoonal rain with some evaporation prior to or during infiltration and partly from bottom of ponds, canals and infiltration of groundwater withdrawn for irrigation. Relatively high tritium content of the shallow groundwater indicates local recharge, while the deep groundwater with very low tritium is recharged mainly from distant areas. At places the deep aquifer has relatively high tritium, indicating mixing of groundwater of shallow and deep aquifers. Metals such as copper, lead, arsenic, cadmium, aluminium, nickel and chromium are also
Understanding wetland sub-surface hydrology using geologic and isotopic signatures
Sikdar, P. K.; Sahu, P.
2009-07-01
This paper attempts to utilize hydrogeology and isotope composition of groundwater to understand the present hydrological processes prevalent in a freshwater wetland, source of wetland groundwater, surface water/groundwater interaction and mixing of groundwater of various depth zones in the aquifer. This study considers East Calcutta Wetlands (ECW) - a freshwater peri-urban inland wetland ecosystem located at the lower part of the deltaic alluvial plain of South Bengal Basin and east of Kolkata city. This wetland is well known over the world for its resource recovery systems, developed by local people through ages, using wastewater of the city. Geological investigations reveal that the sub-surface geology is completely blanketed by the Quaternary sediments comprising a succession of silty clay, sand of various grades and sand mixed with occasional gravels and thin intercalations of silty clay. At few places the top silty clay layer is absent due to scouring action of past channels. In these areas sand is present throughout the geological column and the areas are vulnerable to groundwater pollution. Groundwater mainly flows from east to west and is being over-extracted to the tune of 65×103 m3/day. δ18O and δD values of shallow and deep groundwater are similar indicating resemblance in hydrostratigraphy and climate of the recharge areas. Groundwater originates mainly from monsoonal rain with some evaporation prior to or during infiltration and partly from bottom of ponds, canals and infiltration of groundwater withdrawn for irrigation. Relatively high tritium content of the shallow groundwater indicates local recharge, while the deep groundwater with very low tritium is recharged mainly from distant areas. At places the deep aquifer has relatively high tritium, indicating mixing of groundwater of shallow and deep aquifers. Metals such as copper, lead, arsenic, cadmium, aluminium, nickel and chromium are also present in groundwater of various depths. Therefore
Spatial distribution of groundwater recharge and base flow: Assessment of controlling factors
Directory of Open Access Journals (Sweden)
Z. Zomlot
2015-09-01
New hydrological insights for the region: The average resulting recharge is 235 mm/year and occurs mainly in winter. The overall moderate correlation between base flow estimates and modeled recharge rates indicates that base flow is a reasonable proxy of recharge. Groundwater recharge variation was explained in order of importance by precipitation, soil texture and vegetation cover; while base flow variation was strongly controlled by vegetation cover and groundwater depth. The results of this study highlight the important role of spatial variables in estimation of recharge and base flow. In addition, the prominent role of vegetation makes clear the potential importance of land-use changes on recharge and hence the need to include a proper strategy for land-use change in sustainable management of groundwater resources.
International Nuclear Information System (INIS)
Buaphan, C.; Yangme, W.; Wannakao, L.; Sriboonlue, V.; Tassanasorn, A.; Buapeng, S.
1999-01-01
Investigation of groundwater origin by using isotopic compositions for evaluation of high productive deep aquifers in Khon Kaen Province is emphasized on hydrogeology and isotopes technique. The study area consists of Mesozoic sedimentary rocks and unconsolidated sediments of Quaternary. Phu Tok aquifers in the southern part of the study area are mainly confined in very well sorted, fine grained sandstone as well as in fractures and joints. They extend from Ban Tha Pra to Ban Phai covering area 500 km 2 . Depth to the aquifers is from 20 to 250 m, while their piezometric surface ranges from 0.35 m to 15 m from the ground surface. Their thickness range from 50 to 100 m. The transmissivity is from 0.45 to 1,047 m 2 /d on the pumping rate of 48-1,200 m 3 /d with drawdown of less than 10% and rough annual safe yield is 83.34x10 6 m 3 . The water is very good in quality for drinking, except for the TDS and total hardness around aquifer boundary. The groundwater and surface water are analysed for stable and radioactive isotopes, including 2 H, 18 O, 3 H and 14 C. The results show that the shallow groundwater of the depth less than 50 m is originated by direct recharge of rainfall between 180 and 6,820 a. The groundwater flow is relatively rapid from west to east and northwest to southeast, the high productive deep aquifer of Phu Tok flow radiate from recharging area to all direction. However, the groundwater flow rate based on 14 C analyses for Phu Tok is 2 to 3 m/a. Within some areas the flow is about 8 m/a, while the unconsolidated aquifers along the Phong River give flow rate about 4 m/a. The deeper aquifers also have direct rain recharge the same as the above aquifers but the flow rate are lower, especially the deepest aquifer at the depth of nearly 200 m indicated no direct rain recharge with age of more than 20 000 a, which is confirmed with the amount of tritium less than 1.0 TU. (author)
Fate of human viruses in groundwater recharge systems
Energy Technology Data Exchange (ETDEWEB)
Vaughn, J.M.; Landry, E.F.
1980-03-01
The overall objective of this research program was to determine the ability of a well-managed tertiary effluent-recharge system to return virologically acceptable water to the groundwater aquifer. The study assessed the quality of waters renovated by indigenous recharge operations and investigated a number of virus-soil interrelationships. The elucidation of the interactions led to the establishment of basin operating criteria for optimizing virus removal. Raw influents, chlorinated tertiary effluents, and renovated wastewater from the aquifer directly beneath a uniquely designed recharge test basin were assayed on a weekly basis for the presence of human enteroviruses and coliform bacteria. High concentrations of viruses were routinely isolated from influents but were isolated only on four occasions from tertiary-treated sewage effluents. In spite of the high quality effluent being recharged, viruses were isolated from the groundwater observation well, indicating their ability to penetrate the unsaturated zone. Results of poliovirus seeding experiments carried out in the test basin clearly indicated the need to operate recharge basins at low (e.g. 1 cm/h) infiltration rates in areas having soil types similar to those found at the study site. The method selected for reducing the test basin infiltration rate involved clogging the basin surface with settled organic material from highly turbid effluent. Alternative methods for slowing infiltration rates are discussed in the text.
Optimization of control bars patterns and fuel recharges of coupled form
International Nuclear Information System (INIS)
Mejia S, D.M.; Ortiz S, J.J.
2006-01-01
In this work a system coupled for the optimization of fuel recharges and control bars patterns in boiling water reactors (BWR by its initials in English) is presented. It was used a multi state recurrent neural net like optimization technique. This type of neural net has been used in the solution of diverse problems, in particular the design of patterns of control bars and the design of the fuel recharge. However, these problems have been resolved in an independent way with different optimization techniques. The system was developed in FORTRAN 77 language, it calls OCORN (Optimization of Cycles of Operation using Neural Nets) and it solves both problems of combinatory optimization in a coupled way. OCORN begins creating a seed recharge by means of an optimization through the Haling principle. Later on a pattern of control bars for this recharge seed is proposed. Then a new fuel recharge is designed using the control bars patterns previously found. By this way an iterative process begins among the optimization of control bars patterns and the fuel recharge until a stop criteria it is completed. The stop criteria is completed when the fuel recharges and the control bars patterns don't vary in several successive iterations. The final result is an optimal fuel recharge and its respective control bars pattern. In this work the obtained results by this system for a cycle of balance of 18 months divided in 12 steps of burnt are presented. The obtained results are very encouraging, since the fuel recharge and the control bars pattern, its fulfill with the restrictions imposed in each one of the problems. (Author)
Slow and preferential flow in the unsaturated zone and its impact on stable isotope composition
International Nuclear Information System (INIS)
Seiler, K.P.
2001-01-01
Stable isotope methods (δ 18 O and δ 2 H) have been used investigate the importance of bypass flow in the unsaturated zone which leads to unproductive water loss during flood irrigation. Field experiments have been carried out in Jordan and Pakistan in order to determine the occurrence of bypass flow, its amount and its velocity compared to piston flow. Results show that there is not only an advective component of flow (bypass flow) but a diffusive tracer exchange between piston and bypass flow. Infiltration calculations and analysis of tracer distributions are used to show that at the research sites, bypass flow amounts to about 25% of water recharged during winter. This estimate is important as it provides an assessment of the amount of water that passes the root zone and directly recharges groundwater. (author)
Verbeiren, Boud; Weerasinghe, Imeshi; Vanderhaegen, Sven; Canters, Frank; Uljee, Inge; Engelen, Guy; Jacquemin, Ingrid; Tychon, Bernard; Vangelis, Harris; Tsakiris, George; Batelaan, Okke; Huysmans, Marijke
2015-04-01
Drought is mainly regarded as a purely natural phenomenon, driven by the natural variation in precipitation or rather the lack of precipitation. Nowadays many river catchments are, however, altered by human activities having direct effects on the catchment landscape and hydrological response. In case of the occurrence of drought events in those catchments it becomes more complex to determine the effects of drought. To what extent is the hydrological response a direct result of the natural phenomenon and what is the role of the human factor? In this study we focus on the effects of droughts on groundwater recharge. Reliable estimation of groundwater recharge in space and time is of utmost importance for sustainable management of groundwater resources. Groundwater recharge forms the main source for replenishing aquifers. The main factors influencing groundwater recharge are the soil and topographic characteristics, land use and climate. While the first two influencing factors are relatively static, the latter two are (highly) dynamic. Differentiating between the contributions of each of these influencing factors to groundwater recharge is a challenging but important task. On the one hand, the occurrence of meteorological drought events is likely to cause direct, potentially deteriorating, effects on groundwater recharge. On the other hand, this is also the case for on-going land-use dynamics such as extensive urbanisation. The presented methodology aims at distinguishing in space and time between climate (drought-related) and land-use (human-induced) effects, enabling to assess the effects of drought on groundwater recharge. The physically-based water balance model WetSpass is used to calculate groundwater recharge in a distributed way (space and time) for the Dijle-Demer catchments in Belgium. The key issue is to determine land-use dynamics in a consistent way. A land-use timeseries is build based on four base maps. Via a change trajectory analysis the consistency
Determining Changes in Groundwater Quality during Managed Aquifer Recharge
Gambhir, T.; Houlihan, M.; Fakhreddine, S.; Dadakis, J.; Fendorf, S. E.
2016-12-01
Managed aquifer recharge (MAR) is becoming an increasingly prevalent technology for improving the sustainability of freshwater supply. However, recharge water can alter the geochemical conditions of the aquifer, mobilizing contaminants native to the aquifer sediments. Geochemical alterations on deep (>300 m) injection of highly treated recycled wastewater for MAR has received limited attention. We aim to determine how residual disinfectants used in water treatment processes, specifically the strong oxidants chloramine and hydrogen peroxide, affect metal mobilization within deep injection wells of the Orange County Water District. Furthermore, as the treated recharge water has very low ionic strength (44.6 mg L-1 total dissolved solids), we tested how differing concentrations of magnesium chloride and calcium chloride affected metal mobilization within deep aquifers. Continuous flow experiments were conducted on columns dry packed with sediments from a deep injection MAR site in Orange County, CA. The effluent was analyzed for shifts in water quality, including aqueous concentrations of arsenic, uranium, and chromium. Interaction between the sediment and oxic recharge solution causes naturally-occurring arsenopyrite to repartition onto iron oxides. The stability of arsenic on the newly precipitated iron oxides is dependent on pH changes during recharge.
Recharge and Aquifer Response: Manukan Island’s Aquifer, Sabah, Malaysia
Directory of Open Access Journals (Sweden)
Sarva Mangala Praveena
2010-01-01
Full Text Available Manukan Island is a small island located in North-West of Sabah, Malaysia was used as a case study area for numerical modeling of an aquifer response to recharge and pumping rates. The results in this study present the variations of recharge into the aquifer under the prediction simulations. The recharge rate increases the water level as indicated by hydraulic heads. This shows that it can alter groundwater of Manukan Island which has been suffering from an overexploration in its unconfined the aquifer. The increase in recharge rate (from 600 mm/year to 750 mm/year increases the water level indicated by hydraulic heads. A reduction in pumping rate (from 0.072 m3/day to 0.058 m3/day not only increases the amount of water levels in aquifer but also reduces the supply hence a deficit in supply. The increase in hydraulic heads depends on the percentage reduction of pumping and recharges rates. The well water has 1978.3 mg/L chloride with current pumping (0.072 m3/day and recharge rates (600 mm/year. However, with an increased of recharge rate and current pumping rate it has decreased about 1.13%. In addition, reduction in pumping rate made the chloride concentration decreased about 2.8%. In general, a reduction in pumping with an increase in recharge rate leads to a decreased in chloride concentrations within the vicinity of cone of depression. Next, to further develop the numerical model, the model should focus on climate change variables such as consequences of climate change are increase in air temperature, increase in sea surface temperature, and more extreme weather conditions. These parameters are considered critical parameters for climate change impact modeling in aquifers. The behavior of the aquifer and its sustainable pumping rate can be done by applying a computer modeling component.
International Nuclear Information System (INIS)
Wei Keqin; Lin Ruifen; Wang Zhixiang
1988-01-01
A comprehensive environmental isotope investigation of several complex groundwater systems and the mixing of groundwater with surface water in the region of Taiyuan, Shanxi Province of China, is presented. Environmental isotopes, including stable isotopes, tritium and uranium series in water and its activity ratio 234 U/ 238 U are applied to divide karstic groundwaters into separate Xishan and Dongshan systems. The Xishan karstic water system shows a great scattering of isotope data. This results from the mixing of karstic groundwater and surface water from the Fenhe River. The Dongshan system is homogeneous and karstic water is tritium free and its age should be more than 50-100 a. The increase in uranium activity ratio, which is correlated with the length of the flow paths, shows the run-off direction of the Dongshan karstic water system towards the major natural outlet, the Lancun Spring. The altitudes of recharge of Xishan and Dongshan karstic waters are evaluated as 1400 m and 1300 m, respectively. The ages of fissure groundwaters in metamorphic rocks are determined in terms of their tritium content. Some practical considerations upon groundwater management are also drawn from isotope results. (author). 9 refs, 10 figs, 9 tabs
Energy Technology Data Exchange (ETDEWEB)
Lyles, B.F.; Edkins, J.; Jacobson, R.L.; Hess, J.W.
1990-11-01
The temporal variations of ion and isotope geochemistry were observed at six selected springs on the Nevada Test Site, Nye County, Nevada and included: Cane, Whiterock, Captain Jack, Topopah, Tippipah, and Oak Springs. The sites were monitored from 1980 to 1982 and the following parameters were measured: temperature, pH, electrical conductance, discharge, cations (Ca{sup 2+}, Mg{sup 2+}. Na{sup +}, K{sup +}), anions Cl{sup {minus}}, SO{sub 4}{sup 2{minus}}. HCO{sub 3}{sup {minus}}, silica, stable isotopes ({delta}{sup 18}O, {delta}D, {delta}{sup 13}C), and radioactive isotopes ({sup 3}H, {sup 14}C). A more detailed study was continued from 1982 to 1988 at Cane and Whiterock Springs. Field microloggers were installed at these sites in 1985 to measure the high frequency response of temperature, electrical conductance, and discharge to local precipitation. Stage fluctuations near the discharge point dissolve minerals/salts as groundwater inundates the mineralized zone immediately above the equilibrium water table. This phenomena was most noticeable at Whiterock Spring and lagged the discharge response by several hours. Stable isotope analysis of precipitation and groundwater suggests a 1.5 to 2 month travel time for meteoric water to migrate from the recharge area to the discharge point. Groundwater age determinations suggest a mean age of approximately 30 years at Whiterock Spring and possibly older at Cane Spring. However, the short travel time and geochemical integrity of recharge pulses suggest that the waters are poorly mixed along the flow paths. 25 refs., 25 figs., 24 tabs.
Groundwater recharge and flow on Montserrat, West Indies: Insights from groundwater dating
Directory of Open Access Journals (Sweden)
Brioch Hemmings
2015-09-01
New hydrological insights: δ2H and δ18O analysis indicates uniform recharge elevations for groundwaters on Montserrat. CFC-11 and CFC-12 analysis reveals age differences between isotopically similar, high elevation springs and low elevation aquifer waters. Low CFC concentrations within a confined low elevation aquifer suggest water ages of ∼45 years. High CFC concentrations in the northern and western springs are explained by rapid infiltration of cool (high CFC concentration rainfall into saturated compartments, with flow through the vadose zone to the phreatic zone dominated by compartment flow. Lower CFC concentrations in a number of aligned warmer springs suggest a contribution from older, warmer waters from depth. Temperatures and CFC concentrations indicate older component supply rates of up to 8 L/s to the highest yielding spring on Centre Hills, with contributions of up to 75% in the warmest spring waters.
Aspects of the isotope hydrology of the Great Artesian Basin, Australia
International Nuclear Information System (INIS)
Airey, P.L.; Calf, G.E.; Campbell, B.L.; Hartley, P.E.; Roman, D.
1979-01-01
A study has been made of the isotope hydrology of the principal Jurassic aquifer of the Queensland portion of the Great Artesian Basin down-gradient of the recharge area. Much of the data have been interpreted in terms of the residence times of the groundwater samples which were up to 350,000 years. It is postulated that the observed systematic variations in the chloride levels reflect variations in the rate of infiltration of recycled salt throughout the late Quaternary. The minimum and maximum in the chloride curve correlate with the last glacial and interglacial period respectively. The bicarbonate ion levels are perturbed by the dissolution of carbonate minerals. About 0.1% of the aquifer material would have been dissolved since the mid-Tertiary when the present hydrodynamic conditions were established if dissolution rates calculated from the geochemical model are representative. The D/H ratios were found to be extremely constant. The 46 wells sited away from the recharge area have a mean deltaD of -41.8 per mille and a standard deviation of 1.1. There was no isotopic evidence for exchange of oxygen between water and the host rock despite the long contact periods, sometimes at elevated temperatures. A 226 Ra, 238 U survey showed that radium is frequently in excess despite extensive leaching since the Tertiary times and the fact that the time scales associated with the transport of water are large compared with the half life of 226 Ra. (author)
International Nuclear Information System (INIS)
Thompson, D.A.; Macauley-Newcombe, R.G.
1996-04-01
Ceramic insulators are integral parts of numerous components essential for the heating control and diagnostic measurement of fusion plasmas. For safe and reliable reactor operations it is necessary to be able to predict the resultant tritium inventories and permeation fluxes through these materials. Some materials being considered are Al 2 O 3 (both as single crystal sapphire and polycrystalline alumina) and BeO. This report contains results of ion-implantation, thermal absorption (diffusion loading) and ion-beam analysis experiments performed in 1994 and 1995 for ITER task T26/28. The combination of implantation and thermal absorption capabilities enable us to load samples with hydrogen isotopes under differing conditions. 13 figs., 1 tab., 11 refs
The Guarani Aquifer System: estimation of recharge along the Uruguay-Brazil border
Gómez, Andrea A.; Rodríguez, Leticia B.; Vives, Luis S.
2010-11-01
The cities of Rivera and Santana do Livramento are located on the outcropping area of the sandstone Guarani Aquifer on the Brazil-Uruguay border, where the aquifer is being increasingly exploited. Therefore, recharge estimates are needed to address sustainability. First, a conceptual model of the area was developed. A multilayer, heterogeneous and anisotropic groundwater-flow model was built to validate the conceptual model and to estimate recharge. A field campaign was conducted to collect water samples and monitor water levels used for model calibration. Field data revealed that there exists vertical gradients between confining basalts and underlying sandstones, suggesting basalts could indirectly recharge sandstone in fractured areas. Simulated downward flow between them was a small amount within the global water budget. Calibrated recharge rates over basalts and over outcropping sandstones were 1.3 and 8.1% of mean annual precipitation, respectively. A big portion of sandstone recharge would be drained by streams. The application of a water balance yielded a recharge of 8.5% of average annual precipitation. The numerical model and the water balance yielded similar recharge values consistent with determinations from previous authors in the area and other regions of the aquifer, providing an upper bound for recharge in this transboundary aquifer.
Energy Technology Data Exchange (ETDEWEB)
Li, J. [Key Laboratory of Engineering Geomechanics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, J.; Wang, X. [Hydrogeology and Engineering Geology Team of Beijing, Beijing 100037 (China); Pang, Z. [Key Laboratory of Engineering Geomechanics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)
2013-07-01
Environmental isotopes and chemical compositions are useful tools for the study of groundwater flow systems. Groundwater of the Chaobai River catchment, Beijing was sampled for chemical and stable isotopes analyses in 2005. Geochemical signatures evolve progressively from CaMg-HCO{sub 3} to NaK-HCO{sub 3}, and then to Na-HCO{sub 3} compositions as groundwater flows from the mountain to discharge areas. Groundwater can be divided into two groups on the basis of stable isotope compositions: ancient groundwater and modern groundwater. Modern groundwater (-9.90/00 to -6.60/00 for δ{sup 18}O) plots along a line with a slope of 4.0 on a δ{sup 2}H versus δ{sup 18}O diagram, reflecting evaporation during the process of recharge, whereas ancient groundwater samples (30 to 12 Ka.) are different in isotopic composition (-11.00/00 and -68.20/00 for δ{sup 18}O and δ{sup 2}H, respectively), reflecting the cold and arid climate in the last glacial period. The results have important implications for groundwater management in Beijing City. (authors)
Modelling of recharge and pollutant fluxes to urban groundwaters
International Nuclear Information System (INIS)
Thomas, Abraham; Tellam, John
2006-01-01
Urban groundwater resources are of considerable importance to the long-term viability of many cities world-wide, yet prediction of the quantity and quality of recharge is only rarely attempted at anything other than a very basic level. This paper describes the development of UGIf, a simple model written within a GIS, designed to provide estimates of spatially distributed recharge and recharge water quality in unconfined but covered aquifers. The following processes (with their calculation method indicated) are included: runoff and interception (curve number method); evapotranspiration (Penman-Grindley); interflow (empirical index approach); volatilization (Henry's law); sorption (distribution coefficient); and degradation (first order decay). The input data required are: meteorological data, landuse/cover map with event mean concentration attributes, geological maps with hydraulic and geochemical attributes, and topographic and water table elevation data in grid form. Standard outputs include distributions of: surface runoff, infiltration, potential recharge, ground level slope, interflow, actual recharge, pollutant fluxes in surface runoff, travel times of each pollutant through the unsaturated zone, and the pollutant fluxes and concentrations at the water table. The process of validation has commenced with a study of the Triassic Sandstone aquifer underlying Birmingham, UK. UGIf predicts a similar average recharge rate for the aquifer as previous groundwater flow modelling studies, but with significantly more spatial detail: in particular the results indicate that recharge through paved areas may be more important than previously thought. The results also highlight the need for more knowledge/data on the following: runoff estimation; interflow (including the effects of lateral flow and channelling on flow times and therefore chemistry); evapotranspiration in paved areas; the nature of unsaturated zone flow below paved areas; and the role of the pipe network
Cartwright, Ian; Weaver, Tamie R.; Simmons, Craig T.; Fifield, L. Keith; Lawrence, Charles R.; Chisari, Robert; Varley, Simon
2010-01-01
SummaryA low-salinity (total dissolved solids, TDS, Australia. Hydraulic heads, surface water elevations, δ 18O values, major ion geochemistry, 14C activities, and 3H concentrations show that the lens is recharged from the Murray River largely through the riverbank with limited recharge through the floodplain. Recharge of the lens occurs mainly at high river levels and the low-salinity groundwater forms baseflow to some river reaches during times of low river levels. Within the lens, flow through the shallow Channel Sands and deeper Parilla Sands aquifers is sub-horizontal. While the Blanchetown Clay locally separates the Channel Sands and the Parilla Sands, the occurrence of recently recharged low-salinity groundwater below the Blanchetown Clay suggests that there is considerable leakage through this unit, implying that it is not an efficient aquitard. The lateral margin of the lens with the regional groundwater (TDS >25,000 mg/L) is marked by a hectometer to kilometer scale transition in TDS concentrations that is not stratigraphically controlled. Rather this boundary represents a mixing zone with the regional groundwater, the position of which is controlled by the rate of recharge from the river. The lens is part of an active and dynamic hydrogeological system that responds over years to decades to changes in river levels. The lens has shrunk during the drought of the late 1990s to the mid 2000s, and it will continue to shrink unless regular high flows in the Murray River are re-established. Over longer timescales, the rise of the regional water table due to land clearing will increase the hydraulic gradient between the regional groundwater and the groundwater in the lens, which will also cause it to degrade. Replacement of low-salinity groundwater in the lens with saline groundwater will ultimately increase the salinity of the Murray River reducing its utility for water supply and impacting riverine ecosystems.
Energy Technology Data Exchange (ETDEWEB)
Ben Moussa, A.; Zouari, K. [Laboratory of Radio-Analysis and Environment, ENIS, Sfax (Tunisia); Kurttas, T. [Isotope Hydrology Section, International Atomic Energy Agency, Vienna (Austria)
2013-07-15
The combination of major element geochemistry, stable ({delta}{sup 18}O, {delta}{sup 2}H) and radioactive ({sup 3}H, {sup 14}C) isotopes has provided a comprehensive understanding of the natural and anthropogenic processes that control groundwater mineralization as well as the sources of different groundwater bodies within the Hammamet-Nabeul unconfined aquifer (Cap Bon peninsula, northeastern Tunisia). The geochemical examination shows the dominance of Na-Cl and Ca-SO{sub 4} water types resulting from the dissolution of halite and gypsum, the dedolomitization and the cation exchange process. Additionally, the return flow process in relation with the long term flood irrigation practice contributes to the mineralization by producing high amounts of nitrate. The stable isotope signatures reveal the existence of two groundwater groups. The non-evaporated groundwaters with relatively depleted contents, reflecting recharge at higher altitudes; and evaporated groundwaters with enriched contents highlighting the influence of return flow of irrigation waters. Tritium contents in these two groups provide evidence of the presence of pre- 1950 and post-1960 recharge periods. Carbon-14 activities in shallow wells, in spite of their contamination by organic {sup 14}C, confirm the recent origin of the groundwaters in the study area. (author)
Directory of Open Access Journals (Sweden)
Pengpeng Zhou
2017-01-01
Full Text Available Groundwater sustainability has become a critical issue for Zhanjiang (China because of serious groundwater level drawdown induced by overexploitation of its coastal multilayered aquifer system. It is necessary to understand the origins, material sources, hydrochemical processes, and dynamics of the coastal groundwater in Zhanjiang to support its sustainable management. To this end, an integrated analysis of hydrochemical and isotopic data of 95 groundwater samples was conducted. Hydrochemical analysis shows that coastal groundwater is fresh; however, relatively high levels of Cl−, Mg2+, and total dissolved solid (TDS imply slight seawater mixing with coastal unconfined groundwater. Stable isotopes (δ18O and δ2H values reveal the recharge sources of groundwater in the multilayered aquifer system. The unconfined groundwater originates from local modern precipitation; the confined groundwater in mainland originates from modern precipitation in northwestern mountain area, and the confined groundwater in Donghai and Leizhou is sourced from rainfall recharge during an older period with a colder climate. Ionic relations demonstrate that silicate weathering, carbonate dissolutions, and cation exchange are the primary processes controlling the groundwater chemical composition. Declining trends of groundwater level and increasing trends of TDS of the confined groundwater in islands reveal the landward extending tendency of the freshwater-seawater mixing zone.
Stable isotope composition of surface and groundwater in Baja California, Mexico
International Nuclear Information System (INIS)
Kretzschmar, Thomas G.; Frommen, Theresa
2013-01-01
Based on a total of 135 stable isotope analysis (δ 18 O, δD) carried out on surface and groundwater samples, as well as on rainwater samples between 2004 and 2011 in 5 different regions in Baja California, an isotopic evaluation of the region was established. The results showed a depletion gradient of -0.25 0/00 δ 18 O per 100 m rise in elevation throughout the study area. Considering an unaltered δ 18 O signature for the thermal springs, the recharge areas of these waters are at elevations over 1400 m outside of the present watersheds, indicating the presence of regional flow systems next to the local flow regime feeding the cold springs and wells. The Mesa de Andrade area has a completely different signature with values of -105 for δ 18 O and -13 for δD. (authors)
Reconnaissance Estimates of Recharge Based on an Elevation-dependent Chloride Mass-balance Approach
Energy Technology Data Exchange (ETDEWEB)
Charles E. Russell; Tim Minor
2002-08-31
Significant uncertainty is associated with efforts to quantity recharge in arid regions such as southern Nevada. However, accurate estimates of groundwater recharge are necessary to understanding the long-term sustainability of groundwater resources and predictions of groundwater flow rates and directions. Currently, the most widely accepted method for estimating recharge in southern Nevada is the Maxey and Eakin method. This method has been applied to most basins within Nevada and has been independently verified as a reconnaissance-level estimate of recharge through several studies. Recharge estimates derived from the Maxey and Eakin and other recharge methodologies ultimately based upon measures or estimates of groundwater discharge (outflow methods) should be augmented by a tracer-based aquifer-response method. The objective of this study was to improve an existing aquifer-response method that was based on the chloride mass-balance approach. Improvements were designed to incorporate spatial variability within recharge areas (rather than recharge as a lumped parameter), develop a more defendable lower limit of recharge, and differentiate local recharge from recharge emanating as interbasin flux. Seventeen springs, located in the Sheep Range, Spring Mountains, and on the Nevada Test Site were sampled during the course of this study and their discharge was measured. The chloride and bromide concentrations of the springs were determined. Discharge and chloride concentrations from these springs were compared to estimates provided by previously published reports. A literature search yielded previously published estimates of chloride flux to the land surface. {sup 36}Cl/Cl ratios and discharge rates of the three largest springs in the Amargosa Springs discharge area were compiled from various sources. This information was utilized to determine an effective chloride concentration for recharging precipitation and its associated uncertainty via Monte Carlo simulations
Kiryukhin, A. V.; Polyakov, A. Y.; Usacheva, O. O.; Kiryukhin, P. A.
2018-05-01
The Mutnovsky geothermal area is part of the Eastern Kamchatka active volcano belt. Mutnovsky, 80 kY old and an aging strato-volcano (a complex of 4 composite volcanic cones), acts as a magma- and water-injector into the 25-km-long North Mutnovsky extension zone. Magmatic injection events (dykes) are associated with plane-oriented MEQ (Micro Earth Quakes) clusters, most of them occurring in the NE sector of the volcano (2 × 10 km2) at elevations from -4 to -2 km, while some magmatic injections occur at elevations from -6.0 to -4.0 km below the Mutnovsky production field. Water recharge of production reservoirs is from the Mutnovsky volcano crater glacier (+1500 to +1800 masl), which was confirmed by water isotopic data (δD, δ18O) of production wells at an earlier stage of development. The Mutnovsky (Dachny) 260-310 °C high-temperature production geothermal reservoir with a volume of 16 km3 is at the junction of NNE- and NE-striking normal faults, which coincides with the current dominant dyke injection orientation. TOUGH2-modeling estimates of the reservoir properties are as follows: the reservoir permeability is 90-600 e-15 m2, the deep upflow recharge is 80 kg/s and the enthalpy is 1420 kJ/kg. Modeling was used to reproduce the history of the Mutnovsky (Dachny) reservoir exploitation since 1983 with an effective power of 48 MWe by 2016. Modeling also showed that the reservoir is capable of yielding 65-83 MWe of sustainable production until 2055, if additional production drilling in the SE part of the field is performed. Moreover, this power value may increase to 87-105 MWe if binary technologies are applied. Modeling also shows that the predicted power is sensitive to local meteoric water influx during development. Conceptual iTOUGH2-EOS1sc thermal hydrodynamic modeling of the Mutnovsky magma-hydrothermal system as a whole reasonably explains its evolution over the last 1500-5000 years in terms of heat recharge (dyke injection from the Mutnovsky-4 funnel) and
Changes of the water isotopic composition in unsaturated soils
International Nuclear Information System (INIS)
Feurdean, Victor; Feurdean, Lucia
2001-01-01
Based on the spatial and temporal variations of the stable isotope content in precipitation - as input in subsurface - and the mixing processes, the deuterium content in the water that moves in unsaturated zones was used to determine the most conducive season to recharge, the mechanisms for infiltration of snow or rain precipitation in humid, semi-arid or arid conditions, the episodic cycles of infiltration water mixing with the already present soil water and water vapor and whether infiltration water is or is not from local precipitation. Oscillations in the isotopic profiles of soil moisture can be used to estimate the following aspects: where piston or diffusive flow is the dominant mechanisms of water infiltration; the average velocities of the water movement in vadose zone; the influence of vegetation cover, soil type and slope exposure on the dynamics of water movement in soil; the conditions required for infiltration such as: the matrix, gravity, pressure and osmotic potentials during drainage in unsaturated soil. (authors)
Estimation of alluvial recharge in the semiarid
Andrade,Tafnes S.; Montenegro,Suzana M. G. L.; Montenegro,Abelardo A. de A.; Rodrigues,Diogo F. B.
2014-01-01
In areas where there is irrigated agriculture, the recuperation of water reserves in alluvial aquifers may occur preferentially due to precipitation. Recharging can be evaluated from variation information of water depth measured in piezometers or observation wells. Thus, the aim of this research is to study the recharge in the alluvial aquifer formed by the Mimoso temporary stream in the semiarid region of Pernambuco (PE), Brazil, using the method of the fluctuation of the water level. This s...
How to Recharge a Confined Aquifer: An Exploration of Geologic Controls on Groundwater Storage.
Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.
2017-12-01
Decreased snowpack storage and groundwater overdraft in California has increased interest in managed aquifer recharge (MAR) of excess winter runoff to the Central Valley aquifer system, which has unused storage capacity that far exceeds the state's surface reservoirs. Recharge to the productive, confined aquifer system remains a challenge due to the presence of nearly-ubiquitous, multiple silt and clay confining units that limit recharge pathways. However, previous studies have identified interconnected networks of sand and gravel deposits that bypass the confining units and accommodate rapid, high-volume recharge to the confined aquifer system in select locations. We use the variably-saturated, fully-integrated groundwater/surface-water flow code, ParFlow, in combination with a high-resolution, transition probability Markov-chain geostatistical model of the subsurface geologic heterogeneity of the east side of the Sacramento Valley, CA, to characterize recharge potential across a landscape that includes these geologic features. Multiple 180-day MAR simulations show that recharge potential is highly dependent on subsurface geologic structure, with a several order-of-magnitude range of recharge rates and volumes across the landscape. Where there are recharge pathways to the productive confined-aquifer system, pressure propagation in the confined system is widespread and rapid, with multi-kilometer lateral pressure propagation. Although widespread pressure propagation occurs in the confined system, only a small fraction of recharge volume is accommodated there. Instead, the majority of recharge occurs by filling unsaturated pore spaces. Where they outcrop at land surface, high-K recharge pathways fill rapidly, accommodating the majority of recharge during early time. However, these features become saturated quickly, and somewhat counterintuitively, the low-K silt and clay facies accommodate the majority of recharge volume during most of the simulation. These findings
Predicting groundwater recharge for varying land cover and climate conditions - a global meta-study
Mohan, Chinchu; Western, Andrew W.; Wei, Yongping; Saft, Margarita
2018-05-01
Groundwater recharge is one of the important factors determining the groundwater development potential of an area. Even though recharge plays a key role in controlling groundwater system dynamics, much uncertainty remains regarding the relationships between groundwater recharge and its governing factors at a large scale. Therefore, this study aims to identify the most influential factors of groundwater recharge, and to develop an empirical model to estimate diffuse rainfall recharge at a global scale. Recharge estimates reported in the literature from various parts of the world (715 sites) were compiled and used in model building and testing exercises. Unlike conventional recharge estimates from water balance, this study used a multimodel inference approach and information theory to explain the relationship between groundwater recharge and influential factors, and to predict groundwater recharge at 0.5° resolution. The results show that meteorological factors (precipitation and potential evapotranspiration) and vegetation factors (land use and land cover) had the most predictive power for recharge. According to the model, long-term global average annual recharge (1981-2014) was 134 mm yr-1 with a prediction error ranging from -8 to 10 mm yr-1 for 97.2 % of cases. The recharge estimates presented in this study are unique and more reliable than the existing global groundwater recharge estimates because of the extensive validation carried out using both independent local estimates collated from the literature and national statistics from the Food and Agriculture Organization (FAO). In a water-scarce future driven by increased anthropogenic development, the results from this study will aid in making informed decisions about groundwater potential at a large scale.
Isotope hydrology study of Kalamos region (Attiki) and of the Assopos river basin
International Nuclear Information System (INIS)
Leontiadis, J.L.
1980-10-01
The isotopic composition of the water was used to determine the mechanism of recharge of the Assopos river basin and that of the Kalamos springs issuing brackish water near the coast. The results of the study permitted the catchment of the water before its salinization. A quantity of 73000 m 3 per day is now pumped and used as additional drinkable water for the major area of Athens covering about the 1/6 of the corresponding mean daily consumption. (T.A.)
Comparing groundwater recharge and base flow in the Bukmoongol ...
Indian Academy of Sciences (India)
model, also known as the Rorabaugh Method. (Rorabaugh 1960; Daniel 1976; Rutledge 2007b), estimates groundwater recharges for each stream- flow peak using the recession-curve-displacement method. It is based on an analytical model that describes groundwater discharge subsequent to recharge to the water table ...
Changes in groundwater recharge under projected climate in the upper Colorado River basin
Tillman, Fred; Gangopadhyay, Subhrendu; Pruitt, Tom
2016-01-01
Understanding groundwater-budget components, particularly groundwater recharge, is important to sustainably manage both groundwater and surface water supplies in the Colorado River basin now and in the future. This study quantifies projected changes in upper Colorado River basin (UCRB) groundwater recharge from recent historical (1950–2015) through future (2016–2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 climate projections. Simulated future groundwater recharge in the UCRB is generally expected to be greater than the historical average in most decades. Increases in groundwater recharge in the UCRB are a consequence of projected increases in precipitation, offsetting reductions in recharge that would result from projected increased temperatures.
Catchment-scale groundwater recharge and vegetation water use efficiency
Troch, P. A. A.; Dwivedi, R.; Liu, T.; Meira, A.; Roy, T.; Valdés-Pineda, R.; Durcik, M.; Arciniega, S.; Brena-Naranjo, J. A.
2017-12-01
Precipitation undergoes a two-step partitioning when it falls on the land surface. At the land surface and in the shallow subsurface, rainfall or snowmelt can either runoff as infiltration/saturation excess or quick subsurface flow. The rest will be stored temporarily in the root zone. From the root zone, water can leave the catchment as evapotranspiration or percolate further and recharge deep storage (e.g. fractured bedrock aquifer). Quantifying the average amount of water that recharges deep storage and sustains low flows is extremely challenging, as we lack reliable methods to quantify this flux at the catchment scale. It was recently shown, however, that for semi-arid catchments in Mexico, an index of vegetation water use efficiency, i.e. the Horton index (HI), could predict deep storage dynamics. Here we test this finding using 247 MOPEX catchments across the conterminous US, including energy-limited catchments. Our results show that the observed HI is indeed a reliable predictor of deep storage dynamics in space and time. We further investigate whether the HI can also predict average recharge rates across the conterminous US. We find that the HI can reliably predict the average recharge rate, estimated from the 50th percentile flow of the flow duration curve. Our results compare favorably with estimates of average recharge rates from the US Geological Survey. Previous research has shown that HI can be reliably estimated based on aridity index, mean slope and mean elevation of a catchment (Voepel et al., 2011). We recalibrated Voepel's model and used it to predict the HI for our 247 catchments. We then used these predicted values of the HI to estimate average recharge rates for our catchments, and compared them with those estimated from observed HI. We find that the accuracies of our predictions based on observed and predicted HI are similar. This provides an estimation method of catchment-scale average recharge rates based on easily derived catchment
Directory of Open Access Journals (Sweden)
E. Kristensen
2018-02-01
Full Text Available Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC, coloured dissolved organic matter (CDOM and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5–45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only, total nitrogen (TN, lake only, total dissolved phosphorus (TDP, groundwater only, total phosphorus (TP, lake only, δ18O ∕ δ16O isotope ratios and fluorescent dissolved organic matter (FDOM components derived from parallel factor analysis (PARAFAC. The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS. The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs of the lake (0.25–3.5 years in 0.25-year increments. These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration
Chafouq, D.; El Mandour, A.; Elgettafi, M.; Himi, M.; Chouikri, I.; Casas, A.
2018-03-01
The coastal aquifer of Ghis-Nekor (Morocco) was studied to identify the major processes causing salinization of groundwater. In fact, a geochemical approach multi tracer (general chemistry and isotopes - δ2H, δ18O-H2O, δ34S, δ18O-SO4) was utilized, with the hydrodynamics to explain the processes responsible for the salinization of groundwater, and for identttifying areas most vulnerable to seawater intrusion. The recharge of the aquifer is mainly by the Al-Khattabi dam, the Nekor River and the Ghis River, on the eastern border of the plain. The water that feeds the aquifer shows a relatively high level of salinity and for this reason, the majority of sampled wells indicate high values of electric conductivity and total salinity which arrives at 7.5 g L-1. The plot of the geochemical results analyzes of groundwater in the Piper diagram shows two distinct chemical facies; sodium chloride-facies and chlorinated calcium and magnesium sulfated facies. The concentrations of 18O range between -4.15‰ and -5.73‰, while the values of 2H range between -28.4‰ and -41.7‰. The Nekor river water is depleted in heavy isotopes, and the isotopic compositions are in the order on -6‰ for 18O and -40.5‰ for deuterium. Most of the wells have a slope <8 indicating a slight evaporation before infiltration. The data show low and variable d-excess values (range from -0.02‰ to 11.6‰), reflect recharge during different climatic conditions. The isotopic concentrations of 18O-SO4 vary between 4.35‰ and 8.60‰, while the 34S isotope values range from -4.3‰ to 9.9‰. For Ghis River, these values are between -4.4‰ and 4.95‰, respectively, for sulfur and oxygen. The interpretation of the chemical and isotopic results suggesting the intrusion of seawater to increase salinity of groundwater in the region is low. However, only the NE area shows probable contamination of seawater. In contrast, wells are saline independent of seawater intrusion, the origin of the high
Beisner, Kimberly R.; Paretti, Nicholas V.; Tucci, Rachel S.
2016-04-25
Stable isotope delta values (δ18O and δ2H) of precipitation can vary with elevation, and quantification of the precipitation elevation gradient can be used to predict recharge elevation within a watershed. Precipitation samples were analyzed for stable isotope delta values between 2003 and 2014 from the Verde River watershed of north-central Arizona. Results indicate a significant decrease in summer isotopic values overtime at 3,100-, 4,100-, 6,100-, 7,100-, and 8,100-feet elevation. The updated local meteoric water line for the area is δ2H = 7.11 δ18O + 3.40. Equations to predict stable isotopic values based on elevation were updated from previous publications in Blasch and others (2006), Blasch and Bryson (2007), and Bryson and others (2007). New equations were separated for samples from the Camp Verde to Flagstaff transect and the Prescott to Chino Valley transect. For the Camp Verde to Flagstaff transect, the new equations for winter precipitation are δ18O = -0.0004z − 8.87 and δ2H = -0.0029z − 59.8 (where z represents elevation in feet) and the summer precipitation equations were not statistically significant. For the Prescott to Chino Valley transect, the new equations for summer precipitation are δ18O = -0.0005z − 3.22 and δ2H = -0.0022z − 27.9; the winter precipitation equations were not statistically significant and, notably, stable isotope values were similar across all elevations. Interpretation of elevation of recharge contributing to surface and groundwaters in the Verde River watershed using the updated equations for the Camp Verde to Flagstaff transect will give lower elevation values compared with interpretations presented in the previous studies. For waters in the Prescott and Chino Valley area, more information is needed to understand local controls on stable isotope values related to elevation.
International Nuclear Information System (INIS)
Carlin, F.; Magri, G.
1975-01-01
This research is part of the investigations carried out to assess the environmental impact of the Brasimone site in the upper reaches of the Reno River, where a nuclear research plant is under construction. This plant might imply a risk of contamination of the Reno River water by radioactive wastes. Environmental isotope techinques were used to study the interconnections between the Reno River and groundwater and qualitatively to define the flow dynamics between the surface waters and groundwater in the area of Bologna. The Reno River flows across an aquifer consisting of an irregular succession of alluvial beds of sandy gravel, sands and clayey or sandy silts of varying thicknesses. At the two pumping stations of Borgo Panigale and Tiro a Segno, the tritium and 14 C contents of the groundwater regularly decrease with increasing distance from the Reno River. This indicates that there is a contribution of recent water recharged fron the river, and that such a contribution is higher in Borgo Panigale than in Tiro a Segno. At the pumping station of San Vitale di Reno, only recently put into operation and at a distance from the river greater than that of the other two stations, there is no indication of recharge of recent river water. Stable isotopes also show a slight variation with the distance from the river, in agreement with the fact that deep groundwater is a mixture in variable proportions of two components, one of them originating from the river. All these results were possible to achieve only by means of nevironmental isotope techniques. (author)
International Nuclear Information System (INIS)
Dody, A.
1995-08-01
The aim of this work was to characterize the isotopic composition of potential recharge in an arid rocky watershed. Unique field observations were obtained from an arid watershed in the Negev Highlands, Israel, through utilization of the dynamic variations in the isotopic composition of rainfall and runoff. The hydrological system's inputs are rainfall and its isotopic composition. Rainfall and runoff were sampled in eight storms. High variability in the isotopic composition of rainfall was observed during any single rainstorm. The isotopic distribution in the runoff at the outlet of the basin appeared often not to be correlated to the isotopic patterns of the associated rain storm. A new mathematical model was developed to describe these physical processes. The model called A Double-Component Kinematic Wave Flow and Transport Approach, was designated to assess the dynamic isotopic distribution in arid rain storms and runoff. This model simulates the transport of rainfall into overland flow and runoff in an arid rocky watershed with uniformly distributed shallow depression storage. A numerical solution for the problem was developed, to estimate the depression storage parameters. The model also reflects the isotopic memory effect due to the depression storage between sequential rain showers. A good agreement between the observed and computed hydrograph and the change of the δ 18O values in runoff in time confirms the validity of the model. (author) 138 figs., 125 refs
Inferring time‐varying recharge from inverse analysis of long‐term water levels
Dickinson, Jesse; Hanson, R.T.; Ferré, T.P.A.; Leake, S.A.
2004-01-01
Water levels in aquifers typically vary in response to time‐varying rates of recharge, suggesting the possibility of inferring time‐varying recharge rates on the basis of long‐term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño‐Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one‐dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long‐term water level records using southwest aquifers as the case study. Time‐varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.
Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.
Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott
2015-07-07
Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration.
Benefits and Economic Costs of Managed Aquifer Recharge in California
Directory of Open Access Journals (Sweden)
Debra Perrone
2016-07-01
Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss2art4Groundwater management is important and challenging, and nowhere is this more evident than in California. Managed aquifer recharge (MAR projects can play an important role in ensuring California manages its groundwater sustainably. Although the benefits and economic costs of surface water storage have been researched extensively, the benefits and economic costs of MAR have been little researched. Historical groundwater data are sparse or proprietary within the state, often impairing groundwater analyses. General obligation bonds from ballot propositions offer a strategic means of mining information about MAR projects, because the information is available publicly. We used bond-funding applications to identify anticipated MAR project benefits and proposed economic costs. We then compared these costs with actual project costs collected from a survey, and identified factors that promote or limit MAR. Our analysis indicates that the median proposed economic cost for MAR projects in California is $410 per acre-foot per year ($0.33 per cubic meter per year. Increasing Water Supply, Conjunctive Use, and Flood Protection are the most common benefits reported. Additionally, the survey indicates that (1 there are many reported reasons for differences between proposed and actual costs ($US 2015 and (2 there is one primary reason for differences between proposed recharge volumes and actual recharge volumes (AFY: availability of source water for recharge. Although there are differences between proposed and actual costs per recharge volume ($US 2015/AFY, the ranges for proposed costs per recharge volume and actual costs per recharge volume for the projects surveyed generally agree. The two most important contributions to the success of a MAR project are financial support and good communication with stakeholders.
Estimated ground-water recharge from streamflow in Fortymile Wash near Yucca Mountain, Nevada
International Nuclear Information System (INIS)
Savard, C.S.
1998-01-01
The two purposes of this report are to qualitatively document ground-water recharge from stream-flow in Fortymile Wash during the period 1969--95 from previously unpublished ground-water levels in boreholes in Fortymile Canyon during 1982--91 and 1995, and to quantitatively estimate the long-term ground-water recharge rate from streamflow in Fortymile Wash for four reaches of Fortymile Wash (Fortymile Canyon, upper Jackass Flats, lower Jackass Flats, and Amargosa Desert). The long-term groundwater recharge rate was estimated from estimates of the volume of water available for infiltration, the volume of infiltration losses from streamflow, the ground-water recharge volume from infiltration losses, and an analysis of the different periods of data availability. The volume of water available for infiltration and ground-water recharge in the four reaches was estimated from known streamflow in ephemeral Fortymile Wash, which was measured at several gaging station locations. The volume of infiltration losses from streamflow for the four reaches was estimated from a streamflow volume loss factor applied to the estimated streamflows. the ground-water recharge volume was estimated from a linear relation between infiltration loss volume and ground-water recharge volume for each of the four reaches. Ground-water recharge rates were estimated for three different periods of data availability (1969--95, 1983--95, and 1992--95) and a long-term ground-water recharge rate estimated for each of the four reaches
Directory of Open Access Journals (Sweden)
Yang Xu
2017-11-01
Full Text Available To improve the efficiency of utilizing water resources in arid areas, the mechanism of artificial recharge effecting on groundwater reservoir was analyzed in this research. Based on a generalized groundwater reservoir in a two-dimensional sand tank model, different scenarios of the infiltration basin location and recharge intensity are designed to study how to improve the efficiency of groundwater reservoir artificial recharge. The effective storage capacity and the effective storage rate are taken as the main parameters to analyze the relation between recharge water volume and storage capacity. By combining with groundwater flow system theory, FEFLOW (Finite Element subsurface FLOW system is adopted to set up the groundwater numerical model. It is used to verify the experiment results and to make deep analysis on the rule of water table fluctuations and groundwater movement in the aquifer. Based on the model, different scenarios are designed to examine the combined effect of recharge intensity and intermittent periods. The research results show that: the distance between infiltration basin and pumping well should be shortened appropriately, but not too close; increasing recharge intensity helps to enlarge the effective storage capacity, but it can also reduce the effective storage rate, which goes against the purpose of effective utilization of water resources; and, the recharge intensity and recharge duration should be given full consideration by the actual requirements when we take the approach of intermittent recharge to make a reasonable choice.
Estimated ground-water recharge from streamflow in Fortymile Wash near Yucca Mountain, Nevada
Energy Technology Data Exchange (ETDEWEB)
Savard, C.S.
1998-10-01
The two purposes of this report are to qualitatively document ground-water recharge from stream-flow in Fortymile Wash during the period 1969--95 from previously unpublished ground-water levels in boreholes in Fortymile Canyon during 1982--91 and 1995, and to quantitatively estimate the long-term ground-water recharge rate from streamflow in Fortymile Wash for four reaches of Fortymile Wash (Fortymile Canyon, upper Jackass Flats, lower Jackass Flats, and Amargosa Desert). The long-term groundwater recharge rate was estimated from estimates of the volume of water available for infiltration, the volume of infiltration losses from streamflow, the ground-water recharge volume from infiltration losses, and an analysis of the different periods of data availability. The volume of water available for infiltration and ground-water recharge in the four reaches was estimated from known streamflow in ephemeral Fortymile Wash, which was measured at several gaging station locations. The volume of infiltration losses from streamflow for the four reaches was estimated from a streamflow volume loss factor applied to the estimated streamflows. the ground-water recharge volume was estimated from a linear relation between infiltration loss volume and ground-water recharge volume for each of the four reaches. Ground-water recharge rates were estimated for three different periods of data availability (1969--95, 1983--95, and 1992--95) and a long-term ground-water recharge rate estimated for each of the four reaches.
Groundwater recharge in desert playas: current rates and future effects of climate change
McKenna, Owen P.; Sala, Osvaldo E.
2018-01-01
Our results from playas, which are topographic low areas situated in closed-catchments in drylands, indicated that projected climate change in Southwestern USA would have a net positive impact over runon and groundwater recharge beneath playas. Expected increased precipitation variability can cause up to a 300% increase in annual groundwater recharge beneath playas. This increase will overshadow the effect of decreased precipitation amount that could cause up to a 50% decrease in recharge beneath playas. These changes could have a significant impact on groundwater and carbon storage. These results are important given that groundwater resources in Southwestern USA continue to decline due to human consumption outpacing natural recharge of aquifers. Here, we report on groundwater recharge rates ranging from less than 1 mm to greater than 25 mm per year beneath desert playas. Playas located in larger and steeper catchments with finer-textured soils had the highest rates of recharge. Vegetation cover had no effect on recharge beneath playas. We modeled catchment runoff generation and found that the amount of runon a playa receives annually strongly correlated to the rate of groundwater recharge beneath that playa. Runon occurred during precipitation events larger than 20 mm and increased linearly with events above that threshold.
Review: Recharge rates and chemistry beneath playas of the High Plains aquifer, USA
Gurdak, Jason J.; Roe, Cassia D.
2010-12-01
Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a result, there has been considerable scientific debate about the potential for water to infiltrate the relatively impermeable playa floors, travel through the unsaturated zone sediments that are tens of meters thick, and subsequently recharge the High Plains aquifer. This critical review examines previously published studies on the processes that control recharge rates and chemistry beneath playas. Reported recharge rates beneath playas range from less than 1.0 to more than 500 mm/yr and are generally 1-2 orders of magnitude higher than recharge rates beneath interplaya settings. Most studies support the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this review provide science-based implications for management of playas and groundwater resources of the High Plains aquifer and directions for future research.
Isotope studies of UK tufa deposits and associated source waters
International Nuclear Information System (INIS)
Thorpe, P.M.
1981-12-01
Tufa is a secondary deposit of calcium carbonate precipitated from springs and streams. Previous attempts to date tufa deposits directly with 14 C have had limited success. The major problem is to quantify the amount of carbon incorporated in tufa, derived from the dissolution of carbonate bedrock, essentially free of 14 C. The isotopic composition of tufa-depositing streamwaters is similar to that of water recharging aquifers. The 14 C levels of recent tufa layers, at three sites, were similar to those of the source waters. 14 C dates from tufa at these sites suggested a Postglacial origin when corrected for bedrock carbon dilution of 16 to 24%. This dilution was overestimated by consideration of carbon mass balance using characteristic stable carbon isotope compositions (delta 13 C) for the biogenic and bedrock components. This method of correction is often applied to 14 C dates from groundwaters. The carbon isotope composition of spring waters supplying the tufa-depositing streams was realistically explained by a two stage process of carbonate dissolution under open and then closed conditions with respect to gaseous carbon dioxide. Seasonal variations in the 14 C and delta 13 C composition of stream and spring waters, downstream increases in 14 C and delta 13 C and seasonal variations in the oxygen and hydrogen isotopic composition of rainfall are explained. (author)
Isotopes in water resources management. V.2. Proceedings of a symposium
International Nuclear Information System (INIS)
1996-01-01
At present, the thrusts of the IAEA involvement are towards improved management of water resources in regions suffering from water scarcity, assessment of human impact on water resources, e.g. water pollution, and exploration and management of geothermal resources. Lately, novel isotope based techniques have been evolving from specialized laboratories. These trends and challenges are reflected by the scientific contributions to the International Symposium on Isotopes in Water Resources Management, held from 20 to 24 March 1995 in Vienna. The main themes of the symposium were groundwater resources management, with about two thirds of the contributions addressing origin and recharge of groundwater, groundwater dynamics and pollution, modelling approaches, and geothermal and paleowater resources. The remaining third of the contributions were concerned with surface water sediments, unsaturated zones and methodological aspects. These proceedings contain the 43 papers presented and the extended synopses of over 100 poster presentations. Refs, figs, tabs
Stable isotope composition of surface and groundwater in Baja California, Mexico
Energy Technology Data Exchange (ETDEWEB)
Kretzschmar, Thomas G. [CICESE, Carret. Ensenada-Tijuana No 3819, Ensenada 22860 (Mexico); Frommen, Theresa [FU Berlin Malteserstr. 74-100, 12249 Berlin (Germany)
2013-07-01
Based on a total of 135 stable isotope analysis (δ{sup 18}O, δD) carried out on surface and groundwater samples, as well as on rainwater samples between 2004 and 2011 in 5 different regions in Baja California, an isotopic evaluation of the region was established. The results showed a depletion gradient of -0.25 0/00 δ{sup 18}O per 100 m rise in elevation throughout the study area. Considering an unaltered δ{sup 18}O signature for the thermal springs, the recharge areas of these waters are at elevations over 1400 m outside of the present watersheds, indicating the presence of regional flow systems next to the local flow regime feeding the cold springs and wells. The Mesa de Andrade area has a completely different signature with values of -105 for δ{sup 18}O and -13 for δD. (authors)
Land cover controls on depression-focused recharge: an example from southern Ontario
Buttle, J. M.; Greenwood, W. J.
2015-12-01
The Oak Ridges Moraine (ORM) is a critical hydrogeologic feature in southern Ontario. Although previous research has highlighted the implications of spatially-focused recharge in closed topographic depressions for regional groundwater resources, such depression-focused recharge (DFR) has not been empirically demonstrated on the ORM. Permeable surficial sands and gravels mantling much of the ORM imply that water fluxes will largely be vertical recharge rather than lateral downslope transfer into depressions. Nevertheless, lateral fluxes may occur in winter and spring, when concrete frost development encourages surface runoff of rainfall and snowmelt. The potential for DFR was examined under forest and agricultural land cover with similar soils and surficial geology. Soil water contents, soil temperatures and ground frost thickness were measured at the crest and base of closed depressions in two agricultural fields and two forest stands on permeable ORM outcrops. Recharge from late-fall to the end of spring snowmelt was estimated via 1-d water balances and surface-applied bromide tracing. Both forest and agricultural sites experienced soil freezing; however, greater soil water contents prior to freeze-up at the latter led to concrete soil frost development. This resulted in lateral movement of snowmelt and rainfall into topographic depressions and surface ponding, which did not occur in forest depressions. Water balance recharge exceeded estimates from the bromide tracer approach at all locations; nevertheless, both methods indicated DRF exceeded recharge at the depression crest in agricultural areas with little difference in forest areas. Water balance estimates suggest winter-spring DFR (1300 - 2000 mm) is 3-5× recharge on level agricultural sites. Differences in the potential for DFR between agricultural and forest land covers have important implications for the spatial variability of recharge fluxes and the quality of recharging water on the ORM.
Comparing groundwater recharge and base flow in the Bukmoongol ...
Indian Academy of Sciences (India)
Groundwater recharge and base flow using different investigated methods are simulated in the 15-ha Bukmoongol small-forested watershed located at the southern part of Korea.The WHAT system, PART,RORA,PULSE,BFI,and RAP software are used to estimate groundwater recharge or base flow and base flow index from ...
Mechanisms of recharge in a fractured porous rock aquifer in a semi-arid region
Manna, Ferdinando; Walton, Kenneth M.; Cherry, John A.; Parker, Beth L.
2017-12-01
Eleven porewater profiles in rock core from an upland exposed sandstone vadose zone in southern California, with thickness varying between 10 and 62 m, were analyzed for chloride (Cl) concentration to examine recharge mechanisms, estimate travel times in the vadose zone, assess spatial and temporal variability of recharge, and determine effects of land use changes on recharge. As a function of their location and the local terrain, the profiles were classified into four groups reflecting the range of site characteristics. Century- to millennium-average recharge varied from 4 to 23 mm y-1, corresponding to different average Cl concentrations in the vadose zone and in groundwater, the contribution of diffuse flow (estimated at 80%) and preferential flow (20%) to the total recharge was quantified. This model of dual porosity recharge was tested by simulating transient Cl transport along a physically based narrow column using a discrete fracture-matrix numerical model. Using a new approach based on partitioning both water and Cl between matrix and fracture flow, porewater was dated and vertical displacement rates estimated to range in the sandstone matrix from 3 to 19 cm y-1. Moreover, the temporal variability of recharge was estimated and, along each profile, past recharge rates calculated based on the sequence of Cl concentrations in the vadose zone. Recharge rates increased at specific times coincident with historical changes in land use. The consistency between the timing of land use modifications and changes in Cl concentration and the match between observed and simulated Cl concentration values in the vadose zone provide confidence in porewater age estimates, travel times, recharge estimates, and reconstruction of recharge histories. This study represents an advancement of the application of the chloride mass balance method to simultaneously determine recharge mechanisms and reconstruct location-specific recharge histories in fractured porous rock aquifers. The
Induced recharge of an artesian glacial-drift aquifer at Kalamazoo, Michigan
Reed, J.E.; Deutsch, Morris; Wiitala, S.W.
1966-01-01
As part of a program for managing its ground-water supply, the city of Kalamazoo has constructed induced-recharge facilities at the sites of several of its well fields. To determine the benefits of induced recharge in a water-management program, the U.S. Geological Survey, in cooperation with the city, conducted a series of field experiments at a city well field (Station 9). The 12 production wells at the test site penetrate about 160 feet of glacial drift, which can be separated into three general units a lower aquifer, an intervening confining layer, and an upper aquifer. Although the upper aquifer is not tapped by any of the municipal supply wells, it serves as a storage and transmission medium for water from the West Fork Portage Creek. The testing program consisted of four aquifer and three recharge tests. The aquifer tests show that the transmissibility of the upper and lower aquifers ranges from 50,000 to 100,000 gallons per day per foot and indicate that nearly 200 gpm (gallons per minute) leaks through the intervening aquiclude under nonpumping conditions. The object of the three recharge tests (tests 5, 6, and 7) was to observe the effects of induced recharge by varying conditions in the recharge channel. During the three recharge tests, 7 wells were pumped at a total rate averaging about 2,500 gpm. During test 5, inflow to the channel was shut off, and the water level in the channel was allowed to decline. Drawdowns measured during this test were used as a standard for comparison with drawdowns in tests 6 and 7. During test 6, the head in the recharge channel was maintained as constant as possible, and the inflow to the channel was measured. The rate of induced recharge, as indicated by the measured inflow, averaged about 300 gpm. Between tests 6 and 7, the area of the channel was increased from 27,000 to 143,000 square feet. During test 7, the head in the channel was again maintained as constant as possible, but the inflow to the larger channel
Rechargeable batteries materials, technologies and new trends
Zhang, Zhengcheng
2015-01-01
This book updates the latest advancements in new chemistries, novel materials and system integration of rechargeable batteries, including lithium-ion batteries and batteries beyond lithium-ion and addresses where the research is advancing in the near future in a brief and concise manner. The book is intended for a wide range of readers from undergraduates, postgraduates to senior scientists and engineers. In order to update the latest status of rechargeable batteries and predict near research trend, we plan to invite the world leading researchers who are presently working in the field to write
LITERATURE SURVEY ON ISOTOPIC ABUNDANCE RATIO MEASUREMENTS - 2001-2005
International Nuclear Information System (INIS)
HOLDEN, N.E.
2005-01-01
Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Research Library at the Brookhaven Lab, have already been sent to the members of the Atomic Weights Commission, by either Michael Berglund or Thomas Walczyk. In the last few days, I checked the published literature for any other articles in the areas of natural variations in isotopic abundance ratios, measurements of isotopic abundance ratios on samples of extra-terrestrial material and isotopic abundance ratio measurements performed using ICPMS instruments. Hopefully this information will be of interest to members of the Commission, the sub-committee on isotopic abundance measurements (SIAM), members of the former sub-committee on natural isotopic fractionation (SNIF), the sub-committee on extra-terrestrial isotope ratios (SETIR), the RTCE Task Group and the Guidelines Task Group, who are dealing with ICPMS and TIMS comparisons. In the following report, I categorize the publications in one of four areas. Measurements performed using either positive or negative ions with Thermal Ionization Mass Spectrometer, TIMS, instruments; measurements performed on Inductively Coupled Plasma Mass Spectrometer, ICPMS, instruments; measurements of natural variations of the isotopic abundance ratios; and finally measurements on extra-terrestrial samples with instrumentation of either type. There is overlap in these areas. I selected out variations and ET results first and then categorized the rest of the papers by TIMS and ICPMS
Ecohydrologic process modeling of mountain block groundwater recharge.
Magruder, Ian A; Woessner, William W; Running, Steve W
2009-01-01
Regional mountain block recharge (MBR) is a key component of alluvial basin aquifer systems typical of the western United States. Yet neither water scientists nor resource managers have a commonly available and reasonably invoked quantitative method to constrain MBR rates. Recent advances in landscape-scale ecohydrologic process modeling offer the possibility that meteorological data and land surface physical and vegetative conditions can be used to generate estimates of MBR. A water balance was generated for a temperate 24,600-ha mountain watershed, elevation 1565 to 3207 m, using the ecosystem process model Biome-BGC (BioGeochemical Cycles) (Running and Hunt 1993). Input data included remotely sensed landscape information and climate data generated with the Mountain Climate Simulator (MT-CLIM) (Running et al. 1987). Estimated mean annual MBR flux into the crystalline bedrock terrain is 99,000 m(3) /d, or approximately 19% of annual precipitation for the 2003 water year. Controls on MBR predictions include evapotranspiration (radiation limited in wet years and moisture limited in dry years), soil properties, vegetative ecotones (significant at lower elevations), and snowmelt (dominant recharge process). The ecohydrologic model is also used to investigate how climatic and vegetative controls influence recharge dynamics within three elevation zones. The ecohydrologic model proves useful for investigating controls on recharge to mountain blocks as a function of climate and vegetation. Future efforts will need to investigate the uncertainty in the modeled water balance by incorporating an advanced understanding of mountain recharge processes, an ability to simulate those processes at varying scales, and independent approaches to calibrating MBR estimates. Copyright © 2009 The Author(s). Journal compilation © 2009 National Ground Water Association.
Application of environmental isotopes in water resources studies in Latin America
International Nuclear Information System (INIS)
Aravena, Ramon
2001-01-01
The development of urban centers and economical activities, such as agriculture and mining, in Latin America are intimately linked to the availability of water resources. The increasing demand for water and the risks associated to contamination have generated numerous studies related to the evaluation of water resources in this region. In the specific case of groundwater studies, environmental isotopes have played a significant role in these studies ( 18 O, 2 H, 14 C, 13 C). Groundwater provides about 50-60 % of the water resources used in Latin America. Large urban centers such as Lima (Peru), Managua (Nicaragua) and San Jose (Costa Rica) depend mainly on groundwater as a water supply for the population. The agriculture sector is also a major user of groundwater. The Isotope Hydrology Section of the International Atomic Energy Agency based in Vienna has mainly promoted the application of isotope techniques in Latin America. Most of these applications have focussed on the evaluation of the origin and residence time of the groundwater. The groundwater origin is intimately linked to recharge areas whose evaluation is key for the water balance of the aquifer. The evaluation of the groundwater residence time provides information that is relevant for the management of the groundwater system. This presentation will discuss the basic principles of the application of environmental isotopes in hydrology and it will review the current application of isotope techniques in Latin America. Case studies from different Latin American countries will be used to illustrate the main type of application of isotope techniques in groundwater studies in this region (au)
A synopsis of climate change effects on groundwater recharge
Smerdon, Brian D.
2017-12-01
Six review articles published between 2011 and 2016 on groundwater and climate change are briefly summarized. This synopsis focuses on aspects related to predicting changes to groundwater recharge conditions, with several common conclusions between the review articles being noted. The uncertainty of distribution and trend in future precipitation from General Circulation Models (GCMs) results in varying predictions of recharge, so much so that modelling studies are often not able to predict the magnitude and direction (increase or decrease) of future recharge conditions. Evolution of modelling approaches has led to the use of multiple GCMs and hydrologic models to create an envelope of future conditions that reflects the probability distribution. The choice of hydrologic model structure and complexity, and the choice of emissions scenario, has been investigated and somewhat resolved; however, recharge results remain sensitive to downscaling methods. To overcome uncertainty and provide practical use in water management, the research community indicates that modelling at a mesoscale, somewhere between watersheds and continents, is likely ideal. Improvements are also suggested for incorporating groundwater processes within GCMs.
Energy Technology Data Exchange (ETDEWEB)
Cortecci, G.; Dinelli, E.; Boschetti, T. [University of Bologna (Italy). Dept. of Earth and Geological Environmental Sciences; Bolognesi, L. [International Institute for Geothermal Research, Pisa (Italy); Ferrara, G. [University of Pisa (Italy). Dept. of Earth Sciences
2001-02-01
Twenty-two cold and thermal waters from shallow wells sampled in June 1995 in the Vulcano Porto area, Vulcano Island, were analyzed for major and minor chemical constituents, oxygen and hydrogen isotopes and tritium contents, and sulfur isotopes in the dissolved sulfate. The sulfur isotopic composition of the dissolved sulfate ranges between + 0.6 and + 6.5 per mille (mean + 3.7{+-}1.7 per mille), and is interpreted as deriving mainly from fumarolic SO{sub 2} undergoing oxidation in deep and shallow aquifers, with possible minor contributions from oxidation of H{sub 2}S. Dissolution of secondary anhydrite may have been a minor source of the isotopically heavy aqueous sulfate in the cold groundwaters. The chemical and isotopic features of the waters support previous interpretative hydrologic models of Vulcano Porto, which comprise a number of aquifers fed basically by two major end-members, i.e. meteoric water and crater-type fumarolic inputs, the latter in the form of absorbed emissions or condensate. These data, along with the sulfur isotopes of aqueous sulfate, exclude involvement of seawater in the recharge of the groundwater system of the island. (author)
Aspects of the isotope hydrology of the Great Artesian Basin, Australia
International Nuclear Information System (INIS)
Airey, P.L.; Calf, G.E.; Campbell, B.L.; Hartley, P.E.; Roman, D.
1978-01-01
A study has been made of the isotope hydrology of the principal Jurassic aquifer of the Queensland portion of the Great Artesian Basin down-gradient of the recharge area. Much of the data have been interpreted in terms of the residence times of the groundwater samples which were up to 350,000 years. It is postulated that the observed systematic variations in the chloride levels reflect variations in the rate of infiltration of recycled salt throughout the late Quaternary. The minimum and maximum in the chloride curve correlate with the last glacial and interglacial period respectively. The bicarbonate ion levels are perturbed by the dissolution of carbonate minerals. About 0.1 per cent of the aquifer materia would have been dissolved since the mid-tertiary when the present hydrodynamic conditions were established if dissolution rates calculated from the geochemical model are representative. The D/H ratios were found to be extremely constant. The 46 wells sited away from the recharge area have a mean of delta D of -41.8 per mille and a standard deviation of 1.1. There was no isotopic evidence for exchange of oxygen between water and the host rock despite the long contact periods, sometimes at elevated temperatures. A 226 Ra, 238 U survey showed that radium is frequently in excess despite extensive leaching since the Tertiary times and the fact that the time scales associated with the transport of water are large compared with the half life of 226 Ra. (orig.) [de
Assessing recharge using remotely sensed data in the Guarani Aquifer System outcrop zone
Lucas, M. C.; Oliveira, P. T. S.; Melo, D. D.; Wendland, E.
2014-12-01
Groundwater recharge is an essential hydrology component for sustainable water withdrawal from an aquifer. The Guarani Aquifer System (GAS) is the largest (~1.2 million km2) transboundary groundwater reservoir in South America, supplying freshwater to four countries: Brazil, Argentina, Paraguay and Uruguay. However, recharge in the GAS outcrop zones is one of the least known hydrological variables, in part because studies from hydrological data are scarce or nonexistent. We assess recharge using the water-budget as the difference of precipitation (P) and evapotranspiration (ET). Data is derived from remotely sensed estimates of P (TRMM 3B42 V7) and ET (MOD16) in the Onça Creek watershed over the 2004-12 period. This is an upland-flat watershed (slope steepness < 1%) dominated by sand soils and representative of the GAS outcrop zones. We compared the remote sensing approach against Water Table Fluctuation (WTF) method and another water-budget using ground-based measurements. Uncertainty propagation analysis were also performed. On monthly basis, TRMM P exhibited a great agreement with ground-based P data (R2 = 0.86 and RMSE = 41 mm). Historical (2004-12) mean(±sd) satellite-based recharge (Rsat) was 537(±224) mm y-1, while ground-based recharge using water-budget (Rgr) and WTF (Rwtf) method was 469 mm y-1 and 311(±150) mm y-1, respectively. We found that ~440 mm y-1 is a reasonable historical mean (between Rsat, Rgr and Rwtf) recharge for the study area over 2004-2012 period. The latter mean recharge estimate is about 29% of the mean historical P (1,514 mm y-1). Our results provide the first insight about an intercomparison of water budget from remote sensing and measured data to estimate recharge in the GAS outcrop zone. These results should be useful for future studies on assessing recharge in the GAS outcrop zones. Since accurate and precise recharge estimation still is a gap, our recharge satellite-based is considered acceptable for the Onça Creek
Xia, Lu; Gao, Zongjun; Zheng, Xilai; Wei, Jiuchuan
2018-04-01
To investigate the effect of recharge water temperature on bioclogging processes and mechanisms during seasonal managed aquifer recharge (MAR), two groups of laboratory percolation experiments were conducted: a winter test and a summer test. The temperatures were controlled at 5±2 and 15±3 °C, and the tests involved bacterial inoculums acquired from well water during March 2014 and August 2015, for the winter and summer tests, respectively. The results indicated that the sand columns clogged 10 times faster in the summer test due to a 10-fold larger bacterial growth rate. The maximum concentrations of total extracellular polymeric substances (EPS) in the winter test were approximately twice those in the summer test, primarily caused by a 200 μg/g sand increase of both loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). In the first half of the experimental period, the accumulation of bacteria cells and EPS production induced rapid bioclogging in both the winter and summer tests. Afterward, increasing bacterial growth dominated the bioclogging in the summer test, while the accumulation of LB-EPS led to further bioclogging in the winter test. The biological analysis determined that the dominant bacteria in experiments for both seasons were different and the bacterial community diversity was 50% higher in the winter test than that for summer. The seasonal inoculums could lead to differences in the bacterial community structure and diversity, while recharge water temperature was considered to be a major factor influencing the bacterial growth rate and metabolism behavior during the seasonal bioclogging process.
Estimating ground water recharge from topography, hydrogeology, and land cover.
Cherkauer, Douglas S; Ansari, Sajjad A
2005-01-01
Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.
Majumder, S.; Datta, S.; Nath, B.; Neidhardt, H.; Roman-Ross, G.; Berner, Z.; Hidalgo, M.; Chatterjee, D.; Sarkar, S.
2017-12-01
Large-scale groundwater abstraction was hypothesized to be one of the important factors controlling release and distribution of arsenic (As) in aquifers of Bengal Basin. In this study, we studied the groundwater/surface water geochemistry of two different geomorphic domains within the Chakdaha Block, West Bengal, to identify potential influences of groundwater withdrawal on the hydrochemical evolution of the aquifer. This has been done as a function of different water inputs (monsoon rain, irrigation and downward percolation from surface water impoundments) to the groundwater system and associated As mobilization. A low-land flood plain (with relatively more reducing aquifer) and a natural levee (less reducing aquifer) have been chosen for this purpose. The stable isotopic signatures of oxygen (δ18O) and hydrogen (δ2H) falls sub-parallel to the Global Meteoric Water Line (GMWL), with precipitation and subsequent evaporation seems to be the major controlling factor on the water isotopic composition. This shows a contribution of evaporation influenced water, derived from various surface water bodies, pointing at large-scale groundwater withdrawal helping drawdown of the evaporated surface water. In case of flood plain wells, the stable isotope composition and the Cl/Br molar ratio in local groundwater have revealed vertical recharge within the flood plain area to be the major recharge process, especially during the post-monsoon season. However, both evaporation and vertical mixing are visibly controlling the groundwater recharge in the natural levee area. A possible inflow of organic carbon to the aquifer during the monsoonal recharge process is noticeable, with an increase in dissolved organic carbon (DOC) concentration from 1.33 to 6.29 mg/L on passing from pre- to post-monsoon season. Concomitant increase in AsT, Fe(II) and HCO3- during the post monsoon season, being more pronounced in the flood plain samples, indicates a possible initial episode of reductive
Wu, X.; Wang, Y.; Wang, X. S.; Hu, B.
2017-12-01
Stable isotope δ2H, δ18O and d-excess values of water have previously been used to study the hydraulic connection of groundwater between the surrounding areas such as Heihe River Basin, Qilian Mountain and the Badain Jaran desert (BJD), China. We choose to focus on the effects of strong evaporation on the isotopic characteristics of water in the desert to better understand the origin of water in the BJD. A series of evaporation experiments were conducted in the desert to examine how it may change during evaporation and infiltration under local environmental conditions. Evaporation from open water was monitored in two experiments using local groundwater and lake water, respectively. And evaporation of soil water was observed in three pits which were excavated to different depths below a flat ground surface to install the evaporation-infiltration systems. Water samples were also collected from lakes, a spring and local unconfined aquifer for analyses of stable hydrogen and oxygen isotope ratios, and d-excess values in the BJD. The results show that water isotope contents became progressively enriched along an evaporation line, and the d-excess values decreased with the evaporation. The strong relationship of d-excess and δ18O values was observed from both the experiments and the water samples of groundwater and lakes, which is considered to be a signature of strong evaporation. Also, all the values of groundwater and lake water samples fall along with the evaporation line established through the evaporation experiments, indicating that lakes and groundwater in the study area have evolved from meteoric precipitation under modern or similar to modern climatic conditions. Analysis of a few previously published d-excess and δ18O values of groundwater from the BJD, Lake Eyre Basin, Australia, and Jabal Hafit mountain, United Arab Emirates reveals strong relationships between the two, suggesting similar recharge processes as observed in the BJD. This study demonstrated
Isotope studies of a thick unsaturated zone in a semi-arid area of Southern Africa
International Nuclear Information System (INIS)
Butler, M.J.; Verhagen, B.Th.
2001-01-01
Unsaturated zone profiles ranging in depth from 8 m to 22 m were obtained by hand augering an aeolian sand cover in the southern reaches of the semi-arid Kalahari thirstland. Moisture contents were rather low (<3 wt.%); in situ moisture chloride concentrations, measured by selective ion electrode following elutriation, are generally <500 ppm. Deuterium in the moisture was measured mass spectrometrically by direct quantitative conversion to hydrogen on zinc metal of moist soil samples. A novel technique of direct equilibration was developed for oxygen-18 analysis. Neither a thermonuclear tritium peak nor a stable isotope evaporation inversion near the surface could be observed in any of the profiles. Remarkable differences both laterally and vertically are observed in most parameters measured between profiles taken a few tens of metres apart. At greater depths, these differences become less pronounced. Recharge estimates based on chloride differ markedly from those obtained from tritium. Although the stable isotope values of the underlying saturated zone are similar to moisture in the deeper sections of the unsaturated zone profiles, the markedly lower chloride concentrations point towards preferential or bypass flow as an important mechanism of ground water recharge in the area. This can be regarded as a benchmark site on account of the wealth of unsaturated zone data as well as the detailed and ongoing rainfall record. (author)
The effect of modeled recharge distribution on simulated groundwater availability and capture.
Tillman, F D; Pool, D R; Leake, S A
2015-01-01
Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins along mountain fronts, by flowing overland to infiltrate along ephemeral channels that often traverse basins in the area, or by some combination of these processes. The importance of accurately simulating recharge distributions is a current topic of discussion among hydrologists and water managers in the region, but no comparative study has been performed to analyze the effects of different recharge distributions on groundwater simulations. This study investigates the importance of the distribution of aquifer recharge in simulating regional groundwater flow in basin-fill aquifers by calibrating a groundwater-flow model to four different recharge distributions, all with the same total amount of recharge. Similarities are seen in results from steady-state models for optimized hydraulic conductivity values, fit of simulated to observed hydraulic heads, and composite scaled sensitivities of conductivity parameter zones. Transient simulations with hypothetical storage properties and pumping rates produce similar capture rates and storage change results, but differences are noted in the rate of drawdown at some well locations owing to the differences in optimized hydraulic conductivity. Depending on whether the purpose of the groundwater model is to simulate changes in groundwater levels or changes in storage and capture, the distribution of aquifer recharge may or may not be of primary importance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Climate variability and vadose zone controls on damping of transient recharge
Corona, Claudia R.; Gurdak, Jason J.; Dickinson, Jesse; Ferré, T.P.A.; Maurer, Edwin P.
2017-01-01
Increasing demand on groundwater resources motivates understanding of the controls on recharge dynamics so model predictions under current and future climate may improve. Here we address questions about the nonlinear behavior of flux variability in the vadose zone that may explain previously reported teleconnections between global-scale climate variability and fluctuations in groundwater levels. We use hundreds of HYDRUS-1D simulations in a sensitivity analysis approach to evaluate the damping depth of transient recharge over a range of periodic boundary conditions and vadose zone geometries and hydraulic parameters that are representative of aquifer systems of the conterminous United States (U.S). Although the models were parameterized based on U.S. aquifers, findings from this study are applicable elsewhere that have mean recharge rates between 3.65 and 730 mm yr–1. We find that mean infiltration flux, period of time varying infiltration, and hydraulic conductivity are statistically significant predictors of damping depth. The resulting framework explains why some periodic infiltration fluxes associated with climate variability dampen with depth in the vadose zone, resulting in steady-state recharge, while other periodic surface fluxes do not dampen with depth, resulting in transient recharge. We find that transient recharge in response to the climate variability patterns could be detected at the depths of water levels in most U.S. aquifers. Our findings indicate that the damping behavior of transient infiltration fluxes is linear across soil layers for a range of texture combinations. The implications are that relatively simple, homogeneous models of the vadose zone may provide reasonable estimates of the damping depth of climate-varying transient recharge in some complex, layered vadose zone profiles.
Use of isotope techniques in water resources inventory planning and development
International Nuclear Information System (INIS)
1979-01-01
The seminar, sponsored jointly by the IAEA, UNESCO, and WHO, was organized by the Isotope Hydrology Section for hydrologists and hydrogeologists from English-speaking African countries who have primary administrative and technical responsibility in planning, implementing, and supervising programmes in the field of water resources in their countries. The aim of the seminar was to discuss and to inform the participants of both the theoretical and applied aspects of isotope techniques in hydrology and their potential use in studies dealing with water resources inventory, planning, and development. A similar regional seminar was organized in 1973 by the IAEA in Mexico City for Latin- American countries. In 1979, such a seminar will be held for French-speaking African countries. The Nairobi seminar was held at the East African Institute for Meteorological Training and Research. It was opened by the Minister for Water Development of the Kenyan Government, Dr. Gikonyo Kiano, who stressed the importance of water development problems in the African region and who appreciated the IAEA/UNESCO/WHO initiative in holding the seminar on isotope techniques in water resources in Nairobi. The programme of seminar lectures and discussions included the following topics. 1 Basic principles of radioisotope techniques and stable isotope ratios in hydrology 2. Tritium and radiocarbon as environmental tracers for dating water bodies 3 Isotope techniques in studying the origin of groundwater, recharge, and flow of groundwater. 4. Isotope techniques for identification of surface and groundwater relationships. 5 Surface water studies including lake dynamics, discharge measurements and sediment transport 6. Isotope methods in aquifer characteristics. 7 Isotope methods in geothermal resources prospecting. 8. Isotope techniques in hydraulics engineering. Each topic was illustrated with detailed descriptions of case studies During discussions, participants presented important problems (of water
High-performance rechargeable batteries with fast solid-state ion conductors
Energy Technology Data Exchange (ETDEWEB)
Farmer, Joseph C.
2017-06-27
A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.
Regional Assessment of Groundwater Recharge in the Lower Mekong Basin
Directory of Open Access Journals (Sweden)
Guillaume Lacombe
2017-12-01
Full Text Available Groundwater recharge remains almost totally unknown across the Mekong River Basin, hindering the evaluation of groundwater potential for irrigation. A regional regression model was developed to map groundwater recharge across the Lower Mekong Basin where agricultural water demand is increasing, especially during the dry season. The model was calibrated with baseflow computed with the local-minimum flow separation method applied to streamflow recorded in 65 unregulated sub-catchments since 1951. Our results, in agreement with previous local studies, indicate that spatial variations in groundwater recharge are predominantly controlled by the climate (rainfall and evapotranspiration while aquifer characteristics seem to play a secondary role at this regional scale. While this analysis suggests large scope for expanding agricultural groundwater use, the map derived from this study provides a simple way to assess the limits of groundwater-fed irrigation development. Further data measurements to capture local variations in hydrogeology will be required to refine the evaluation of recharge rates to support practical implementations.
Directory of Open Access Journals (Sweden)
W. G. Darling
2003-01-01
Full Text Available The utility of stable isotopes as tracers of the water molecule has a long pedigree. The study reported here is part of an attempt to establish a comprehensive isotopic 'baseline' for the British Isles as background data for a range of applications. Part 1 of this study (Darling and Talbot, 2003 considered the isotopic composition of rainfall in Britain and Ireland. The present paper is concerned with the composition of surface waters and groundwater. In isotopic terms, surface waters (other than some upland streams are poorly characterised in the British Isles; their potential variability has yet to be widely used as an aid in hydrological research. In what may be the first study of a major British river, a monthly isotopic record of the upper River Thames during 1998 was obtained. This shows high damping of the isotopic variation compared to that in rainfall over most of the year, though significant fluctuations were seen for the autumn months. Smaller rivers such as the Stour and Darent show a more subdued response to the balance between runoff and baseflow. The relationship between the isotopic composition of rainfall and groundwater is also considered. From a limited database, it appears that whereas Chalk groundwater is a representative mixture of weighted average annual rainfall, for Triassic sandstone groundwater there is a seasonal selection of rainfall biased towards isotopically-depleted winter recharge. This may be primarily the result of physical differences between the infiltration characteristics of rock types, though other factors (vegetation, glacial history could be involved. In the main, however, groundwaters appear to be representative of bulk rainfall within an error band of 0.5‰ δ18O. Contour maps of the δ18O and δ2H content of recent groundwaters in the British Isles show a fundamental SW-NE depletion effect modified by topography. The range of measured values, while much smaller than those for rainfall, still covers
Soil Water Balance and Recharge Monitoring at the Hanford Site – FY 2010 Status Report
Energy Technology Data Exchange (ETDEWEB)
Fayer, Michael J.; Saunders, Danielle L.; Herrington, Ricky S.; Felmy, Diana
2010-10-27
This report summarizes the recharge data collected in FY 2010 at five locations on the Hanford Site in southeastern Washington State. Average monthly precipitation and temperature conditions in FY 2010 were near normal and did not present an opportunity for increased recharge. The recharge monitoring data confirmed those conditions, showing normal behavior in water content, matric head, and recharge rates. Also provided in this report is a strategy for recharge estimation for the next 5 years.
Percolation pond as a method of managed aquifer recharge in a ...
Indian Academy of Sciences (India)
Raicy Mani Christy
2017-07-17
Jul 17, 2017 ... Percolation ponds have become very popular methods of managed aquifer recharge due to their low ... effect of recharge structures by some researchers .... qualitative comparison of observed responses of .... Two types of.
Seibert, Simone; Descourvieres, Carlos; Skrzypek, Grzegorz; Deng, Hailin; Prommer, Henning
2017-05-01
The oxidation of pyrite is often one of the main drivers affecting groundwater quality during managed aquifer recharge in deep aquifers. Data and techniques that allow detailed identification and quantification of pyrite oxidation are therefore crucial for assessing and predicting the adverse water quality changes that may be associated with this process. In this study, we explore the benefits of combining stable sulphur isotope analysis with reactive transport modelling to improve the identification and characterisation of pyrite oxidation during an aquifer storage and recovery experiment in a chemically and physically heterogeneous aquifer. We characterise the stable sulphur isotope signal (δ34S) in both the ambient groundwater and the injectant as well as its spatial distribution within the sedimentary sulphur species. The identified stable sulphur isotope signal for pyrite was found to vary between -32 and +34‰, while the signal of the injectant ranged between +9.06 and +14.45‰ during the injection phase of the experiment. Both isotope and hydrochemical data together suggest a substantial contribution of pyrite oxidation to the observed, temporally variable δ34S signals. The variability of the δ34S signal in pyrite and the injectant were both found to complicate the analysis of the stable isotope data. However, the incorporation of the data into a numerical modelling approach allowed to successfully employ the δ34S signatures as a valuable additional constraint for identifying and quantifying the contribution of pyrite oxidation to the redox transformations that occur in response to the injection of oxygenated water.
The rechargeable aluminum-ion battery
Jayaprakash, N.; Das, S. K.; Archer, L. A.
2011-01-01
We report a novel aluminium-ion rechargeable battery comprised of an electrolyte containing AlCl3 in the ionic liquid, 1-ethyl-3-methylimidazolium chloride, and a V2O5 nano-wire cathode against an aluminium metal anode. The battery delivered a
Isotopic investigations of mineral waters from Someseni - Cluj, Romania
International Nuclear Information System (INIS)
Cuna, Stela; Berdea, Petre; Baciu, Calin
2001-01-01
The Someseni mineral water spring area is located in the eastern part of Cluj-Napoca city, Romania, at the base of the first alluvial terrace of the Somesul Mic River. The presence of waters with therapeutical qualities in this area is known since the early 1920's. Only five springs are active at this moment. From a geological point of view, the mineral aquifer is located on the western border of the Neogene Transylvanian Basin. The Someseni spring area is situated in the axial zone of an anticline with salt core. Marls, with frequent intercalations of sandstones and volcanic tuffs dominate the lithology of these deposits. We have studied the flows of these waters by means of the hydrogen and oxygen isotopes. The method for determining the oxygen isotope composition was by equilibration with CO 2 and measurement of the isotopic ratio of CO 2 . Hydrogen isotope analysis of these waters was carried out on the hydrogen gas obtained by quantitative reduction of water directly in the inlet system of the mass spectrometer. In the interpretation of other authors, there are two distinct circuits of the waters from Someseni: a deep one, which determines a higher mineralisation, the water being in contact for a longer time with the salt massif, and a shallow one, located in alluvial deposits, which have a slight contact with the salt, reflected by its lower mineralisation. In our opinion, there is a single circuit for these mineral waters. The infiltration occurs through previous layers (volcanic tuffs, sandstones) in an unidentified recharging zone, generating a confined aquifer. This assumption can be sustained by the hydrogen and oxygen isotopes uptake of these waters. (authors)
Groundwater recharge estimation under semi arid climate: Case of Northern Gafsa watershed, Tunisia
Melki, Achraf; Abdollahi, Khodayar; Fatahi, Rouhallah; Abida, Habib
2017-08-01
Natural groundwater recharge under semi arid climate, like rainfall, is subjected to large variations in both time and space and is therefore very difficult to predict. Nevertheless, in order to set up any strategy for water resources management in such regions, understanding the groundwater recharge variability is essential. This work is interested in examining the impact of rainfall on the aquifer system recharge in the Northern Gafsa Plain in Tunisia. The study is composed of two main parts. The first is interested in the analysis of rainfall spatial and temporal variability in the study basin while the second is devoted to the simulation of groundwater recharge. Rainfall analysis was performed based on annual precipitation data recorded in 6 rainfall stations over a period of 56 years (1960-2015). Potential evapotranspiration data were also collected from 1960 to 2011 (52 years). The hydrologic distributed model WetSpass was used for the estimation of groundwater recharge. Model calibration was performed based on an assessment of the agreement between the sum of recharge and runoff values estimated by the WetSpass hydrological model and those obtained by the climatic method. This latter is based on the difference calculated between rainfall and potential evapotranspiration recorded at each rainy day. Groundwater recharge estimation, on monthly scale, showed that average annual precipitation (183.3 mm/year) was partitioned to 5, 15.3, 36.8, and 42.8% for interception, runoff, actual evapotranspiration and recharge respectively.
Enhancement of wadi recharge using dams coupled with aquifer storage and recovery wells
Missimer, Thomas M. M.
2014-06-25
Wadi channel recharge to the underlying alluvial aquifer is naturally limited by the flashy nature of flood events, evapotranspiration losses of water from the vadose zone, and aquifer heterogeneity, particularly low vertical hydraulic conductivity. Anthropogenic lowering of the water table in many wadi aquifers has also reduced the potential recharge by increasing the thickness of the vadose zone, causing interflow water loss from surface emergence and evaporation. A method to enhance recharge is to slow the flow within wadi channels by placement of dam structures, thereby ponding water and increasing the vertical head gradient to create a more rapid rate of infiltration and percolation. Effectiveness of wadi dams to enhance aquifer recharge reduces over time due to mud deposition within the reservoir caused by storm events. Up to 80 % of the water in old wadi reservoirs is lost to free-surface evaporation before infiltration and recharge can occur. One method to maintain or increase the rate of recharge is to convey clean water by gravity flow from the reservoir down-gradient to artificially recharge the aquifer using existing wells. This type of system is a low-cost and low-energy recharge method which could greatly enhance groundwater storage in wadi aquifers. Modeling results show that existing wells could store up to 1,000 m3/day under gravity-feed conditions and up to 3,900 m3/day with the shut-in of the well to produce a pressurized system. © 2014 Springer-Verlag Berlin Heidelberg.
Energy Technology Data Exchange (ETDEWEB)
Dody, A [Ben-Gurion Univ. of the Negev, Beersheba (Israel)
1995-08-01
The aim of this work was to characterize the isotopic composition of potential recharge in an arid rocky watershed. Unique field observations were obtained from an arid watershed in the Negev Highlands, Israel, through utilization of the dynamic variations in the isotopic composition of rainfall and runoff. The hydrological system`s inputs are rainfall and its isotopic composition. Rainfall and runoff were sampled in eight storms. High variability in the isotopic composition of rainfall was observed during any single rainstorm. The isotopic distribution in the runoff at the outlet of the basin appeared often not to be correlated to the isotopic patterns of the associated rain storm. A new mathematical model was developed to describe these physical processes. The model called A Double-Component Kinematic Wave Flow and Transport Approach, was designated to assess the dynamic isotopic distribution in arid rain storms and runoff. This model simulates the transport of rainfall into overland flow and runoff in an arid rocky watershed with uniformly distributed shallow depression storage. A numerical solution for the problem was developed, to estimate the depression storage parameters. The model also reflects the isotopic memory effect due to the depression storage between sequential rain showers. A good agreement between the observed and computed hydrograph and the change of the {delta}{sup 18O} values in runoff in time confirms the validity of the model. (author) 138 figs., 125 refs.
Santos, Isaac R; Zhang, Chenming; Maher, Damien T; Atkins, Marnie L; Holland, Rodney; Morgenstern, Uwe; Li, Ling
2017-02-15
Assessing recharge is critical to understanding groundwater and preventing pollution. Here, we investigate recharge in an Australian coastal aquifer using a combination of physical, modelling and geochemical techniques. We assess whether recharge may occur through a pervasive layer of floodplain muds that was initially hypothesized to be impermeable. At least 59% of the precipitation volume could be accounted for in the shallow aquifer using the water table fluctuation method during four significant recharge events. Precipitation events rates were estimated in the area underneath the floodplain clay layer rather than in the sandy area. A steady-state chloride method implied recharge rates of at least 200mm/year (>14% of annual precipitation). Tritium dating revealed long term net vertical recharge rates ranging from 27 to 114mm/year (average 58mm/year) which were interpreted as minimum net long term recharge. Borehole experiments revealed more permeable conditions and heterogeneous infiltration rates when the floodplain soils were dry. Wet conditions apparently expand floodplain clays, closing macropores and cracks that act as conduits for groundwater recharge. Modelled groundwater flow paths were consistent with tritium dating and provided independent evidence that the clay layer does not prevent local recharge. Overall, all lines of evidence demonstrated that the coastal floodplain muds do not prevent the infiltration of rainwater into the underlying sand aquifer, and that local recharge across the muds was widespread. Therefore, assuming fine-grained floodplain soils prevent recharge and protect underlying aquifers from pollution may not be reasonable. Copyright © 2016 Elsevier B.V. All rights reserved.
Isotope study of the groundwater of the Apodi Plateau
International Nuclear Information System (INIS)
Santiago, M.M.F.; Silva, C.M.S.V.; Frischkorn, H.; Manoel Filho, J.; Mendes Filho, J.
2011-01-01
Full text: The environmental isotopes oxygen-18 and deuterium, excellent natural tracers in hydrology, are used to characterize the groundwater stored in the Sedimentary Apodi Basin. They are originating from the Acu Sandstone Formation and from the limestone of the Jandaira Formation. These waters assist the needs from agricultural industry implanted on the top of the Apodi Plateau, responsible for the export of tropical horticulture products. This turns these waters a strategic reserve for the economic and social development of the area, and detailed knowledge of their storage and recharge conditions is necessary in order to maintain a sustainable exploration and an appropriate rational administration. With the objective of understanding the recharge mechanism and the interaction between the two aquifers, hydro chemical parameters, pH, and electric conductivity and isotopes oxygen-18 and deuterium were measured. Samples were collected in two periods, being one during the dry (set/09) and the other one at the beginning of the rainy period (jan/10). Values of δ 18 (in per mil) range from -3.5 to -2.0 in the Jandaira limestone waters, whereas they have an average of only -4.5 in Acu sandstone. Thus Jandaira values indicate the presence of recent waters and the values below - 4.0 in Acu waters indicate the presence of paleowaters, waters that should be considered as strategic reserve. The relationships between the two isotopes measured in the dry and rainy periods are described respectively by the equations δD = 4.0δO 18 - 10.5 and δD = 5.3δO 18 - 1.3. Comparing them to the classical World Meteoric Water Line (δD = 8δO 18 + 10, we identify that especially in the dry period evaporation and/or limestone dissolution play an important role. Electric conductivities of Jandaira waters range from 1000 to 3000μS/cm; waters from Acu sandstone are of lower salinity with a mean value of 500μS/cm. The relationship between the parameters oxygen-18, deuterium and electric
Groundwater Diffuse Recharge and its Response to Climate Changes in Semi-Arid Northwestern China
Directory of Open Access Journals (Sweden)
Lin Deng
2015-01-01
Full Text Available Understanding the processes and rates of groundwater recharge in arid and semi-arid areas is crucial for utilizing and managing groundwater resources sustainably. We obtained three chloride profiles of the unsaturated-zone in the desert/loess transition zone of northwestern China and reconstructed the groundwater recharge variations over the last 11, 21, and 37 years, respectively, using the generalized chloride mass balance (GCMB method. The average recharge rates were 43.7, 43.5, and 45.1 mm yr-1, respectively, which are similar to those evaluated by the chloride mass balance (CMB or GCMB methods in other semi-arid regions. The results indicate that the annual recharge rates were not in complete linear proportion to the corresponding annual precipitations, although both exhibited descending tendencies on the whole. Comparisons between the daily precipitation aggregate at different intensity and recharge rates reveal that the occurrence of relatively heavy daily precipitation per year may contribute to such nonlinearity between annual precipitation and recharge. The possible influences of vegetation cover alterations following precipitation change cannot be excluded as well. The approximately negative correlation between the average annual recharge and temperature suggests that changes in temperature have had significant influences on recharge.
Rechargeable Lithium Metal Cell, Phase I
National Aeronautics and Space Administration — PSI proposes to develop a rechargeable lithium metal cell with energy density >400Wh/kg. This represents a >70% increase as compared to similarly constructed...
Groundwater recharge and sustainability in the High Plains aquifer in Kansas, USA
Sophocleous, M.
2005-01-01
Sustainable use of groundwater must ensure not only that the future resource is not threatened by overuse, but also that natural environments that depend on the resource, such as stream baseflows, riparian vegetation, aquatic ecosystems, and wetlands are protected. To properly manage groundwater resources, accurate information about the inputs (recharge) and outputs (pumpage and natural discharge) within each groundwater basin is needed so that the long-term behavior of the aquifer and its sustainable yield can be estimated or reassessed. As a first step towards this effort, this work highlights some key groundwater recharge studies in the Kansas High Plains at different scales, such as regional soil-water budget and groundwater modeling studies, county-scale groundwater recharge studies, as well as field-experimental local studies, including some original new findings, with an emphasis on assumptions and limitations as well as on environmental factors affecting recharge processes. The general impact of irrigation and cultivation on recharge is to appreciably increase the amount of recharge, and in many cases to exceed precipitation as the predominant source of recharge. The imbalance between the water input (recharge) to the High Plains aquifer and the output (pumpage and stream baseflows primarily) is shown to be severe, and responses to stabilize the system by reducing water use, increasing irrigation efficiency, adopting water-saving land-use practices, and other measures are outlined. Finally, the basic steps necessary to move towards sustainable use of groundwater in the High Plains are delineated, such as improving the knowledge base, reporting and providing access to information, furthering public education, as well as promoting better understanding of the public's attitudinal motivations; adopting the ecosystem and adaptive management approaches to managing groundwater; further improving water efficiency; exploiting the full potential of dryland and
Effect of temporal averaging of meteorological data on predictions of groundwater recharge
Directory of Open Access Journals (Sweden)
Batalha Marcia S.
2018-06-01
Full Text Available Accurate estimates of infiltration and groundwater recharge are critical for many hydrologic, agricultural and environmental applications. Anticipated climate change in many regions of the world, especially in tropical areas, is expected to increase the frequency of high-intensity, short-duration precipitation events, which in turn will affect the groundwater recharge rate. Estimates of recharge are often obtained using monthly or even annually averaged meteorological time series data. In this study we employed the HYDRUS-1D software package to assess the sensitivity of groundwater recharge calculations to using meteorological time series of different temporal resolutions (i.e., hourly, daily, weekly, monthly and yearly averaged precipitation and potential evaporation rates. Calculations were applied to three sites in Brazil having different climatological conditions: a tropical savanna (the Cerrado, a humid subtropical area (the temperate southern part of Brazil, and a very wet tropical area (Amazonia. To simplify our current analysis, we did not consider any land use effects by ignoring root water uptake. Temporal averaging of meteorological data was found to lead to significant bias in predictions of groundwater recharge, with much greater estimated recharge rates in case of very uneven temporal rainfall distributions during the year involving distinct wet and dry seasons. For example, at the Cerrado site, using daily averaged data produced recharge rates of up to 9 times greater than using yearly averaged data. In all cases, an increase in the time of averaging of meteorological data led to lower estimates of groundwater recharge, especially at sites having coarse-textured soils. Our results show that temporal averaging limits the ability of simulations to predict deep penetration of moisture in response to precipitation, so that water remains in the upper part of the vadose zone subject to upward flow and evaporation.
Energy Technology Data Exchange (ETDEWEB)
Panarello, H O [Instituto de Geocronologia y Geologia Isotopica (INGEIS), Buenos Aires (Argentina)
1990-01-01
Results and conclusions obtained under the framework of the 3995/RB research contract between the IAEA and the INGEIS with participation of the Dirreccion de Geologia, Mineria y Aguas Subterraneas (DGMAS) and the Centro Federal de Inversiones (C.F.I.) are presented. From the results the suitability of the isotope techniques for tracing hydrodynamic processes could be confirmed. Recharge condition also have been defined. The exceptional event of flood in the Buenos Aires province that begin in 1986 in connection with abnormal high precipitations targed infiltrating waters with the isotopical signal of the evaporation. This signal was found out in many of the sampled wells and allowed to recognize the recharge, even to significant depths. In the Pinamar and Villa Gesell towns, it was possible to establish the dynamic of wells under seasonal exploitation. In the most of cases water withdrawn in summer was recharged in the immediate precedent pluvious period. Refs, figs and tabs.
Isotope and chemical techniques in assessing groundwater contamination from Metro Manila landfill
International Nuclear Information System (INIS)
Castaneda, Soledad S.; Almoneda, Rosalina V.; Ascano, Luz; Del Castillo, Lorena A.; Fernandez, Lourdes G.; Sucgang, Raymond J.; Iblan, Cynthia L.; Baui, Daniel G.
2007-01-01
The first objective of the investigations is establishing benchmark isotopic characteristics of water sources and baseline concentrations of main environmental parameters related to contamination from the landfill. Water samples were collected from the production wells and surface water in the municipalities in proximity of the landfill, in Rodriguez and in San Mateo. Stable isotope characterization of the deep groundwater and rivers shows isotopic values clustering along the LMWL with ae 18 O ranging from -7.5 promille to -6.5 promille and ae 2 H ranging from - 53.59 promille to -42.91. The shallow groundwater are more isotopically enriched trending towards the evaporation line, with mean ae 18 O and aeD values of -6.46 promille and -44.14 promille, respectively. The mean isotopic signatures of surface water, with mean ae 18 O of -7.19 promille and deep groundwater, with mean ae 18 O of -6.67 promille, in Rodriguez are significantly distinct. San Mateo groundwater appear to be more isotopically enriched, indicating recharge different from that of Rodriguez groundwater. Leachate from the landfill exhibits a distinct isotopic composition from the freshwaters, with ae 18 O and aeD values of -5.58 promille and -31.66 promille. The significant differences in the isotopic signatures of the different water sources in the study area would facilitate detection of contamination from leachate run-off to the surface water, and eventually, to the groundwater. Trace metals in the water samples collected, generally, were below the regulatory limits for drinking water and surface water. Results of elemental determination in the sediment samples obtained from rivers showed that aside from the major crustal elements, Zn, Cu, and Ni were also present in significant amount. (author)
Multiple batch recharging for industrial CZ silicon growth
Fickett, B.; Mihalik, G.
2001-05-01
The Czochralski (CZ) crystal growth process used in the Siemens Solar Industries’ (SSI) Vancouver, WA facility was non-continuous. Each furnace run's production was limited by the size of the starting charge. Once the charge was depleted, the furnace was shut down, cooled, and set back up for the next run. A recharge system was developed which transforms standard CZ growth into a semi-continuous process. Now when the charge is depleted, the crucible can be refilled in situ as the grown ingot is being removed from the furnace. SSI has demonstrated up to 14 recharge cycles in a single run. The resulting benefits included: significant cost reduction, increased yield, increased throughput, reduced energy consumption, improved process capability, reduced material handling requirements, and reduced labor. The recharge system also enables the use of granular silicon, which requires less than 30% of the energy required when manufacturing silicon-starting materials. This significantly reduces the energy “pay-back” time associated with SSI's finished product, photovoltaic panels.
Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D
Directory of Open Access Journals (Sweden)
B. Leterme
2012-08-01
Full Text Available The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain, considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.
Ground-water recharge in Fortymile Wash near Yucca Mountain, Nevada, 1992--1993
International Nuclear Information System (INIS)
Savard, C.S.
1994-01-01
Quantification of the ground-water recharge from streamflow in the Fortymile Wash watershed will contribute to regional ground-water studies. Regional ground-water studies are an important component in the studies evaluating the ground-water flow system as a barrier to the potential migration of radionuclides from the potential underground high-level nuclear waste repository. Knowledge gained in understanding the ground-water recharge mechanisms and pathways in the Pah Canyon area, which is 10 km to the northeast of Yucca Mountain, may transfer to Yucca site specific studies. The current data collection network in Fortymile Canyon does not permit quantification of ground-water recharge, however a qualitative understanding of ground-water recharge was developed from these data
International Nuclear Information System (INIS)
Shamsan, A. M.
2004-01-01
Environmental Isotope Study Of The Well Field of The Sana'a Water Supply and Sanitation Local Corporation (SWSSLC) In Sana'a Basin-Yemen. The water in the deep aquifers of the Sana'a Basin has been investigated using chemical and environmental isotope techniques. To identify the Chemical and the Isotopic characteristics for the well fields of the Sana'a Water Supply And Sanitation Local Corporation (SWSSLC) which withdrawal the water from deep aquifers (Tawilah Sandstone and Volcanics).The Tawilah Sandstone and Volcanic Aquifers represent the main Aquifers in the Sana'a Basin.The chemical and environmental isotope study in Sana'a basin comes out with the following results: 1. The Hydrochemical characteristic in the Sana'a Basin differ from aquifer to another, according to the rock type or formation, It was found that the type of water in the Tawilah sandstone is dominated by Ca- Na- HCO 3 , while the water type Na-Ca- HCO 3 found demonstrated in Volcanic Aquifer. Generally the Hydrochemical composition of groundwater from two aquifers are represent of mixture water. 2. The Groundwater of the deep aquifers for (Tawilah sandstone and Volcanics), indicates that its isotopic constitutes for a 18 O is depleted and tend to be close from the slope 8 of global meteoric water line, which means that this water does not exposed to any evaporation processes, and infiltrated to the aquifers in a cold and humid climatic condition. It is also indicates that the recharge to the deep aquifers comes from the same source and same altitudes, and also there is a hydraulic contact between aquifers. 3. The δ 18 O and δ 2 H values of the groundwater samples from deep aquifers are reflect hydrological regime with limited present day recharge and storage of large volume of fossil ground water .the very low or non-existent Tritium 3 H concentration observed in groundwater also support this conclusion and indicate that the groundwater contains no water recharged in the last four decades
Vesicle-based rechargeable batteries
Energy Technology Data Exchange (ETDEWEB)
Stanish, I.; Singh, A. [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375 (United States); Lowy, D.A. [Nova Research, Inc., 1900 Elkin St., Alexandria, VA 22308 (United States); Hung, C.W. [Department of Chemical Engineering, University of Maryland, College Park, MD 20742 (United States)
2005-05-02
Vesicle-based rechargeable batteries can be fabricated by mounting polymerized vesicles filled with ferrocyanide or ferricyanide to a conductive surface. The potential can be adjusted by changing the concentration ratio of hydroquinone and benzoquinone bound to the vesicle membranes. These batteries show promise as a means of supplying portable power for future autonomous nanosystems. (Abstract Copyright [2005], Wiley Periodicals, Inc.)
Stable Isotope Mapping of Alaskan Grasses and Marijuana
Booth, A. L.; Wooller, M. J.
2008-12-01
The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing
International Nuclear Information System (INIS)
Carucci, Valentina; Petitta, Marco; Aravena, Ramon
2012-01-01
In the Tivoli Plain (Rome, Central Italy) the interaction between shallow and deep groundwater flow systems enhanced by groundwater extraction has been investigated using isotopic and chemical tracers. A conceptual model of the groundwater flowpaths has been developed and verified by geochemical modeling. A combined hydrogeochemical and isotopic investigation using ion relationships such as DIC/Cl − , Ca/(Ca + Mg)/SO 4 /(SO 4 + HCO 3 ), and environmental isotopes (δ 18 O, δ 2 H, 87 Sr/ 86 Sr, δ 34 S and δ 13 C) was carried out in order to determine the sources of recharge of the aquifer, the origin of solutes and the mixing processes in groundwater of Tivoli Plain. Multivariate statistical methods such as principal component analysis and Cluster analyses have confirmed the existence of different geochemical facies and the role of mixing in the chemical composition of the groundwater. Results indicate that the hydrochemistry of groundwater is characterized by mixing between end-members coming directly from carbonate recharge areas and to groundwater circulating in a deeply buried Meso-Cenozoic carbonate sequence. The travertine aquifer is fed by both flow systems, but a local contribution by direct input in the Plain has also been recognized. The stable isotope data ( 18 O, 2 H, 13 C and 34 S) supports the flow system conceptual model inferred from the geochemical data and represents key data to quantify the geochemical mixing in the different groundwaters of the Plain. The results of numerical modeling (PHREEQC) are consistent with the flowpaths derived from the hydrogeochemical conceptual model. The inverse models performed generated the main geochemical processes occurring in the groundwater flow system, which also included mixing. Geochemical and isotope modeling demonstrate an increasing influence of groundwater from the deeply buried aquifer in the travertine aquifer, enhanced by lowering of the travertine aquifer water table due to quarry pumping.
Effect of irrigation return flow on groundwater recharge in an overexploited aquifer in Bangladesh
Touhidul Mustafa, Syed Md.; Shamsudduha, Mohammad; Huysmans, Marijke
2016-04-01
Irrigated agriculture has an important role in the food production to ensure food security of Bangladesh that is home to over 150 million people. However, overexploitation of groundwater for irrigation, particularly during the dry season, causes groundwater-level decline in areas where abstraction is high and surface geology inhibits direct recharge to underlying shallow aquifer. This is causing a number of potential adverse socio-economic, hydrogeological, and environmental problems in Bangladesh. Alluvial aquifers are primarily recharged during monsoon season from rainfall and surface sources. However, return flow from groundwater-fed irrigation can recharge during the dry months. Quantification of the effect of return flow from irrigation in the groundwater system is currently unclear but thought to be important to ensure sustainable management of the overexploited aquifer. The objective of the study is to investigate the effect of irrigation return flow on groundwater recharge in the north-western part of Bangladesh, also known as Barind Tract. A semi-physically based distributed water balance model (WetSpass-M) is used to simulate spatially distributed monthly groundwater recharge. Results show that, groundwater abstraction for irrigation in the study area has increased steadily over the last 29 years. During the monsoon season, local precipitation is the controlling factor of groundwater recharge; however, there is no trend in groundwater recharge during that period. During the dry season, however, irrigation return-flow plays a major role in recharging the aquifer in the irrigated area compared to local precipitation. Therefore, during the dry season, mean seasonal groundwater recharge has increased and almost doubled over the last 29 years as a result of increased abstraction for irrigation. The increase in groundwater recharge during dry season has however no significant effect in the improvement of groundwater levels. The relation between groundwater
A new rechargeable intelligent vehicle detection sensor
International Nuclear Information System (INIS)
Lin, L; Han, X B; Ding, R; Li, G; Lu, Steven C-Y; Hong, Q
2005-01-01
Intelligent Transportation System (ITS) is a valid approach to solve the increasing transportation issue in cities. Vehicle detection is one of the key technologies in ITS. The ITS collects and processes traffic data (vehicle flow, vehicular speed, vehicle density and occupancy ratios) from vehicle detection sensors buried under the road or installed along the road. Inductive loop detector as one type of the vehicle detector is applied extensively, with the characters of stability, high value to cost ratio and feasibility. On the other hand, most of the existing inductive loop vehicle detection sensors have some weak points such as friability of detective loop, huge engineering for setting and traffic interruption during installing the sensor. The design and reality of a new rechargeable intelligent vehicle detection sensor is presented in this paper against these weak points existing now. The sensor consists of the inductive loop detector, the rechargeable batteries, the MCU (microcontroller) and the transmitter. In order to reduce the installing project amount, make the loop durable and easily maintained, the volume of the detective loop is reduced as much as we can. Communication in RF (radio frequency) brings on the advantages of getting rid of the feeder cable completely and reducing the installing project amount enormously. For saving the cable installation, the sensor is supplied by the rechargeable batteries. The purpose of the intelligent management of the energy and transmitter by means of MCU is to minimize the power consumption and prolong the working period of the sensor. In a word, the new sensor is more feasible with smaller volume, wireless communication, rechargeable batteries, low power consumption, low cost, high detector precision and easy maintenance and installation
A new rechargeable intelligent vehicle detection sensor
Energy Technology Data Exchange (ETDEWEB)
Lin, L [Inspiring Technology Research Laboratory, Tianjin University, Tianjin 300072 (China); Han, X B [Inspiring Technology Research Laboratory, Tianjin University, Tianjin 300072 (China); Ding, R [Tianjin University of Technology and Education, Tianjin 300222 (China); Li, G [Inspiring Technology Research Laboratory, Tianjin University, Tianjin 300072 (China); Lu, Steven C-Y [Inspiring Technology Research Laboratory, Tianjin University, Tianjin 300072 (China); Hong, Q [Inspiring Technology Research Laboratory, Tianjin University, Tianjin 300072 (China)
2005-01-01
Intelligent Transportation System (ITS) is a valid approach to solve the increasing transportation issue in cities. Vehicle detection is one of the key technologies in ITS. The ITS collects and processes traffic data (vehicle flow, vehicular speed, vehicle density and occupancy ratios) from vehicle detection sensors buried under the road or installed along the road. Inductive loop detector as one type of the vehicle detector is applied extensively, with the characters of stability, high value to cost ratio and feasibility. On the other hand, most of the existing inductive loop vehicle detection sensors have some weak points such as friability of detective loop, huge engineering for setting and traffic interruption during installing the sensor. The design and reality of a new rechargeable intelligent vehicle detection sensor is presented in this paper against these weak points existing now. The sensor consists of the inductive loop detector, the rechargeable batteries, the MCU (microcontroller) and the transmitter. In order to reduce the installing project amount, make the loop durable and easily maintained, the volume of the detective loop is reduced as much as we can. Communication in RF (radio frequency) brings on the advantages of getting rid of the feeder cable completely and reducing the installing project amount enormously. For saving the cable installation, the sensor is supplied by the rechargeable batteries. The purpose of the intelligent management of the energy and transmitter by means of MCU is to minimize the power consumption and prolong the working period of the sensor. In a word, the new sensor is more feasible with smaller volume, wireless communication, rechargeable batteries, low power consumption, low cost, high detector precision and easy maintenance and installation.
The effects of model complexity and calibration period on groundwater recharge simulations
Moeck, Christian; Van Freyberg, Jana; Schirmer, Mario
2017-04-01
A significant number of groundwater recharge models exist that vary in terms of complexity (i.e., structure and parametrization). Typically, model selection and conceptualization is very subjective and can be a key source of uncertainty in the recharge simulations. Another source of uncertainty is the implicit assumption that model parameters, calibrated over historical periods, are also valid for the simulation period. To the best of our knowledge there is no systematic evaluation of the effect of the model complexity and calibration strategy on the performance of recharge models. To address this gap, we utilized a long-term recharge data set (20 years) from a large weighting lysimeter. We performed a differential split sample test with four groundwater recharge models that vary in terms of complexity. They were calibrated using six calibration periods with climatically contrasting conditions in a constrained Monte Carlo approach. Despite the climatically contrasting conditions, all models performed similarly well during the calibration. However, during validation a clear effect of the model structure on model performance was evident. The more complex, physically-based models predicted recharge best, even when calibration and prediction periods had very different climatic conditions. In contrast, more simplistic soil-water balance and lumped model performed poorly under such conditions. For these models we found a strong dependency on the chosen calibration period. In particular, our analysis showed that this can have relevant implications when using recharge models as decision-making tools in a broad range of applications (e.g. water availability, climate change impact studies, water resource management, etc.).
Stable isotope and radiocarbon analyses at the Stripa test site. Phase I
International Nuclear Information System (INIS)
Fritz, P.; Frape, S.K.; Fontes, J.C.
1985-01-01
The 18 O and 2 H contents of groundwaters in the Stripa granite document that deep and shallow groundwaters have a different origin and history. The lower heavy isotopes contents of the deep waters suggest recharge during a cooler climate and thus, possibly, an older age. This is supported by radiocarbon data-although it is not possible to deduce from much data definite ages or mean residence times of the deep waters. Widely variable carbon-13 contents in aqueous carbon and fracture calcites attest to the heterogeneous environments which characterize(d) these fracture systems: very negative S 13 C values in DIC and calcites provide strong indications that redox processes are active (bacterially mediated) and that both S 13 C of DIC and S 34 S values of aqueous sulfate are affected. This is relevant for an overall description of the geochemical environment, yet it has not been possible to assign a definite origin to the aqueous sulfate of these waters. Isotope data also demonstrate that it is not possible to ''age-date'' the deep waters on the basis of isotope echange reactions between sulfate and water
On-Farm, Almond Orchard Flooding as a Viable Aquifer Recharge Alternative
Ulrich, C.; Nico, P. S.; Wu, Y.; Newman, G. A.; Conrad, M. E.; Dahlke, H. E.
2017-12-01
In 2014, California legislators passed the Sustainable Groundwater Management Act (SGMA), which requires groundwater sustainability agencies (areas) to identify/prioritize water basins, develop current and projected water use/needs, develop a groundwater management plan, develop fees, etc. One of the challenges for implementing SGMA is the lack of data that can support alternative groundwater recharge methods such as on-farm flooding. Prior to anthropogenic river control, river floodplains captured excess water during overbank flow in the rainy season in the CA central valley. Today levees and canals strategically route rainy season high flows to the delta/ocean when irrigation water is not needed. Utilizing farmland once again as infiltration basins for groundwater banking and aquifer recharge could be a viable answer to California's depleted central valley aquifers. Prior to 2017, U.C. Davis had partnered with the Almond Board of California (ABC) and local growers to study the efficacy of agricultural flooding and the effects on annual almond crops (. LBNL joined this team to help understand the conveyance of recharge water, using electrical resistivity tomography (ERT), into the subsurface (i.e. localized fast paths, depth of infiltration, etc.) during flooding events. The fate of the recharge water is what is significant to understanding the viability of on-farm flooding as an aquifer recharge option. In this study two orchards (in Delhi and Modesto, CA), each approximately 2 acres, were flooded during the almond tree dormant period (January), to recharge 2 acre/ft of water into the local aquifers. ERT was used to characterize (soil structure) and monitor water infiltration over a single flooding event to investigate the fate of applied water. Data were collected every hour prior to flooding (baseline), during, and after all flood water had infiltrated (about 5 days total). Our time-lapse ERT results show a heterogeneous soil structure that leads to non
International Nuclear Information System (INIS)
Darling, W.G.; Burgess, W.G.; Hasan, M.K.
2002-01-01
The population of the greater Dhaka metropolitan area is over 8 million and growing at a rate of six percent per year. Much of the water supply for the area is obtained from the underlying Dupi Tila sand aquifer. Intensive exploitation of the aquifer has led to a progressive decline in water levels beneath the parts of the city. The resulting cone of depression is thought likely to be causing the infiltration of surface water, largely from the polluted Buriganga waterway. The use of oxygen and hydrogen stable isotopes in unravelling the subsurface hydrology of the Dhaka area is hindered by the lack of data regarding 'baseline' conditions. Nevertheless it is clear from the evidence obtained from tubewells across the city that there is leakage from the Buriganga river extending several kilometres beneath parts of the urban area, possibly as far as the centre of the city. Carbon stable isotopes and major ion chemistry confirm this general picture; though appear to indicate that polluted river water has not penetrated quite so far towards the city centre. The Dupi Tila is regarded as a multi-layer aquifer on the basis of its hydrogeology and water quality variations with depth. Since there is little stable isotopic evidence for stratification, future investigations should include sensitive recent age indicators to investigate this, and the rates of groundwater movement in general. (author)
An investigation into recharge in South African underground collieries
Energy Technology Data Exchange (ETDEWEB)
Vermeulen, P.D.; Usher, B.H. [University of the Free State, Bloemfontein (South Africa). Inst. of Groundwater Studies
2006-11-15
The Mineral and Petroleum Act of 2002 states that no closure certificate may be issued to mines unless the management of potential pollution to water resources has been addressed. Continuous recharge into the abandoned collieries occurs, and it is important for collieries that close down to plan their future management strategy accordingly. Research has been initiated to determine the recharge into abandoned mines of different mining depths, methods and size. Collieries of a nature similar to these case studies can thus associate with the recharge values obtained. Water balances are of overriding importance in determining recharge and water loss. These vary from mine to mine. Overriding factors are the method of mining, depth of mining, and surface hydrology. High extraction methods (stooping and longwall) invariably disturb the overlying strata more than bord and pillar methods. A summary of the percentage influx to be expected for the various mining methods is as follows: Shallow bord and pillar: 5-10% of the rainfall; Deep bord and pillar with no subsidence: 3-4% of the rainfall; Stooping: 5-12% of the rainfall; Longwall: 6-15% of the rainfall; Rehabilitated opencast: 14-20% of the rainfall. The actual percentages depend largely on specific circumstances.
Energy Technology Data Exchange (ETDEWEB)
Guinot, S
1996-03-15
A new family of solid polymer electrolytes (SPE) based on polyoxyethylene (POE), KOH and water is investigated in view of its use in rechargeable batteries. After a short review on rechargeable batteries, the preparation of various electrolyte compositions is described. Their characterization by differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction and microscopy confirm a multi-phasic structure. Conductivity measurements give values up to 10 sup -3 S cm sup -1 at room temperature. Their use in cells with nickel as negative electrode and cadmium or zinc as positive electrode has been tested; cycling possibility has been shown to be satisfactory. (C.B.) 113 refs.
Nondestructive control of residual stresses during welding and recharge processes
International Nuclear Information System (INIS)
Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Merino, F.; Aragon, B.
1993-01-01
In this work, the stress state of material during welding and recharge processes is controlled with the help of Barkhausen effect. The changes, occurred in the longitudinal and transversal stress profile are show during deposition of welding rings. It is proved that the stress state of the base-material depends on the amount of recharge layers, deposited on it
International Nuclear Information System (INIS)
Robinson, A.P.; Blythe, P.T.; Bell, M.C.; Hübner, Y.; Hill, G.A.
2013-01-01
This paper quantifies the recharging behaviour of a sample of electric vehicle (EV) drivers and evaluates the impact of current policy in the north east of England on EV driver recharging demand profiles. An analysis of 31,765 EV trips and 7704 EV recharging events, constituting 23,805 h of recharging, were recorded from in-vehicle loggers as part of the Switch EV trials is presented. Altogether 12 private users, 21 organisation individuals and 32 organisation pool vehicles were tracked over two successive six month trial periods. It was found that recharging profiles varied between the different user types and locations. Private users peak demand was in the evening at home recharging points. Organisation individual vehicles were recharged primarily upon arrival at work. Organisation pool users recharged at work and public recharging points throughout the working day. It is recommended that pay-as-you-go recharging be implemented at all public recharging locations, and smart meters be used to delay recharging at home and work locations until after 23:00 h to reduce peak demand on local power grids and reduce carbon emissions associated with EV recharging. - Highlights: • Study of EV driver recharging habits in the north east of England. • 7704 electric vehicle recharging events, comprising 23,805 h were collected. • There was minimal recharging during off- peak hours. • Free parking and electricity at point of use encouraged daytime recharging. • Need for financial incentives and smart solutions to better manage recharging demand peaks
Estimating 1970-99 average annual groundwater recharge in Wisconsin using streamflow data
Gebert, Warren A.; Walker, John F.; Kennedy, James L.
2011-01-01
Average annual recharge in Wisconsin for the period 1970-99 was estimated using streamflow data from U.S. Geological Survey continuous-record streamflow-gaging stations and partial-record sites. Partial-record sites have discharge measurements collected during low-flow conditions. The average annual base flow of a stream divided by the drainage area is a good approximation of the recharge rate; therefore, once average annual base flow is determined recharge can be calculated. Estimates of recharge for nearly 72 percent of the surface area of the State are provided. The results illustrate substantial spatial variability of recharge across the State, ranging from less than 1 inch to more than 12 inches per year. The average basin size for partial-record sites (50 square miles) was less than the average basin size for the gaging stations (305 square miles). Including results for smaller basins reveals a spatial variability that otherwise would be smoothed out using only estimates for larger basins. An error analysis indicates that the techniques used provide base flow estimates with standard errors ranging from 5.4 to 14 percent.
International Nuclear Information System (INIS)
2009-05-01
A coordinated research project (CRP) was conducted by the IAEA with the purpose of studying what isotopic and other ancillary data are required to help understand migration of potential contaminants through the unsaturated zone (UZ) into the underlying groundwater. To this end, research projects were conducted in ten countries to study recharge and infiltration processes, as well as contaminant migration in a wide variety of UZ environments. This publication contains the reports of these ten projects and a summary of the accomplishments of the individual projects. The IAEA-TECDOC reviews the usefulness and current status of application of the combined use of isotope and other hydrogeochemical tools for the assessment of flow and transport processes in the UZ. A number of isotope and hydrochemical tools have been used to simultaneously study groundwater recharge and transport of pollutants in the UZ. This information is relevant for assessing the vulnerability of groundwater to contamination. The ten projects covered climates ranging from humid to arid, and water table depths from the near surface to over 600 m. The studies included measuring movement of water, solutes, and gases through the UZ using an assortment of isotope and geochemical tracers and approaches. Contaminant issues have been studied at most of the ten sites and the UZ was found to be very effective in protecting groundwater from most heavy metal contaminants. The publication is expected to be of interest to hydrologists, hydrogeologists and soil scientists dealing with pollution aspects and protection of groundwater resources, as well as counterparts of TC projects in Member States
Mitigation of non-point source of fluoride on groundwater by dug well recharge
Ganesan, G.; Lakshmanan, E.
2017-12-01
Groundwater used for drinking purpose is affected in many regions due to the presence of excess fluoride. The excess intake of fluoride through drinking water causes fluorosis to human in many states of India, including Tamil Nadu. The present study was carried out with the objective of assessing hydrogeochemistry of groundwater and the feasibility of dug well recharge to reduce the fluoride concentration in Vaniyar river basin, Tamil Nadu, India. The major source for fluoride in groundwater of this area is the epidote hornblende gneissic and charnockite which are the major rocks occurring in this region. As a pilot study a cost effective induced recharge structure was constructed at Papichettipatty village in the study region. The study shows that the groundwater level around the recharge site raised up to 2 m from 14.5 m (bgl) and fluoride concentration has decreased from 3.8 mg/l to 0.9 mg/l due to dilution. The advantage of this induced recharge structure is of its low cost, the ease of implementation, improved groundwater recharge and dilution of fluoride in groundwater. An area of about 1.5 km2 has benefited due to this dug well recharge system.
Enhancing emerging organic compound degradation: applying chaotic flow to managed aquifer recharge
Rodríguez-Escales, Paula; Fernandez-Garcia, Daniel; Drechsel, Johannes; Folch, Albert; Sanchez-Vila, Xavier
2017-04-01
The coupling of Managed Aquifer Recharge with soil aquifer remediation treatment, by placing a reactive layer containing organic matter at the bottom of the infiltration pond, is a promising technology to improve the rate of degradation of EOCs. Its success is based on assuming that recharged water and groundwater get well mixed, which is not always true. It has been demonstrated that mixing can be enhanced by inducing chaotic advection through extraction-injection engineering. In this work we analyze how chaotic advection might enhance the spreading of redox conditions with the final aim of improving degradation of a mix of benzotriazoles: benzotriazole, 5-methyl-benzotriazole, and 5-chloro-benzotriazole. The first two compounds are better degraded under aerobic conditions whereas the third one under nitrate reducing conditions. We developed a reactive transport model that describes how a recharged water rich in organic matter mixes with groundwater, how this organic matter is oxidized by different electron acceptors, and how the benzotriazoles are degraded attending for the redox state. The model was tested in different scenarios of recharge, both in homogenous and in heterogenous media. It was found that chaotic flow increases the spreading of the plume of recharged water. Consequently, different redox conditions coexist at a given time within the area affected by recharge, facilitating the degradation of EOCs.
Assessment of check-dam groundwater recharge with water-balance calculations
Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos
2017-04-01
Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without
Chemical and Isotopic Tracers of Groundwater Sustainability: an Overview of New Science Directions
Bullen, T.
2002-12-01
Groundwater sustainability is an emerging concept that is rapidly gaining attention from both scientists and water resource managers, particularly with regard to contamination and degradation of water quality in strategic aquifers. The sustainability of a groundwater resource is a complex function of its susceptibility to factors such as intrusion of poor-quality water from diverse sources, lack of sufficient recharge and reorganization of groundwater flowpaths in response to excessive abstraction. In theory the critical limit occurs when degradation becomes irreversible, such that remediative efforts may be fruitless on a reasonable human time scale. Chemical and isotopic tracers are proving to be especially useful tools for assessment of groundwater sustainability issues such as characterization of recharge, identification of potential sources, pathways and impacts of contaminants and prediction of how hydrology will change in response to excessive abstraction. A variety of relatively cost-efficient tracers are now available with which to assess the susceptibility of groundwater reserves to contamination from both natural and anthropogenic sources, and may provide valuable monitoring and regulatory tools for water resource managers. In this overview, the results of several ongoing groundwater studies by the U.S. Geological Survey will be discussed from the perspective of implications for new science directions for groundwater sustainability research that can benefit water policy development. A fundamental concept is that chemical and isotopic tracers used individually often provide ambiguous information, and are most effective when used in a rigorous "multi-tracer" context that considers the complex linkages between the hydrology, geology and biology of groundwater systems.
Rainfall recharge estimation on a nation-wide scale using satellite information in New Zealand
Westerhoff, Rogier; White, Paul; Moore, Catherine
2015-04-01
Models of rainfall recharge to groundwater are challenged by the need to combine uncertain estimates of rainfall, evapotranspiration, terrain slope, and unsaturated zone parameters (e.g., soil drainage and hydraulic conductivity of the subsurface). Therefore, rainfall recharge is easiest to estimate on a local scale in well-drained plains, where it is known that rainfall directly recharges groundwater. In New Zealand, this simplified approach works in the policy framework of regional councils, who manage water allocation at the aquifer and sub-catchment scales. However, a consistent overview of rainfall recharge is difficult to obtain at catchment and national scale: in addition to data uncertainties, data formats are inconsistent between catchments; the density of ground observations, where these exist, differs across regions; each region typically uses different local models for estimating recharge components; and different methods and ground observations are used for calibration and validation of these models. The research described in this paper therefore presents a nation-wide approach to estimate rainfall recharge in New Zealand. The method used is a soil water balance approach, with input data from national rainfall and soil and geology databases. Satellite data (i.e., evapotranspiration, soil moisture, and terrain) aid in the improved calculation of rainfall recharge, especially in data-sparse areas. A first version of the model has been implemented on a 1 km x 1 km and monthly scale between 2000 and 2013. A further version will include a quantification of recharge estimate uncertainty: with both "top down" input error propagation methods and catchment-wide "bottom up" assessments of integrated uncertainty being adopted. Using one nation-wide methodology opens up new possibilities: it can, for example, help in more consistent estimation of water budgets, groundwater fluxes, or other hydrological parameters. Since recharge is estimated for the entire land
Recharge Data Package for the 2005 Integrated Disposal Facility Performance Assessment
Energy Technology Data Exchange (ETDEWEB)
Fayer, Michael J.; Szecsody, Jim E.
2004-06-30
Pacific Northwest National Laboratory assisted CH2M Hill Hanford Group, Inc., (CHG) by providing estimates of recharge rates for current conditions and long-term scenarios involving disposal in the Integrated Disposal Facility (IDF). The IDF will be located in the 200 East Area at the Hanford Site and will receive several types of waste including immobilized low-activity waste. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the IDF PA Project and from modeling studies conducted for the project. Recharge estimates were provided for three specific site features (the surface barrier; possible barrier side slopes; and the surrounding soil) and four specific time periods (pre-Hanford; Hanford operations; surface barrier design life; post-barrier design life). CHG plans to conduct a performance assessment of the latest IDF design and call it the IDF 2005 PA; this recharge data package supports the upcoming IDF 2005 PA.
Directory of Open Access Journals (Sweden)
Nyoman Suwartha
2012-05-01
Full Text Available The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recharge pond and river at three sampling point to determine existing water quality of the pond. The results showed that recharge rate of the pond between dry season (3.2 mm/day and wet season (6.1 mm/day are considered as insignificant different. The water balance of the recharge pond shows an excessive rate. Various physics and chemical parameters (turbidity, color, TDS, pH, and Cl are found to have concentration lower than the water quality standard. The results suggest that the pond surface water is remain suitable to be recharged into aquifer zone so that sustaining ground water conservation campaign, and it is potential to be utilized as an additional raw water source for domestic water demand of UI Campus Depok.
Trace organic chemicals contamination in ground water recharge.
Díaz-Cruz, M Silvia; Barceló, Damià
2008-06-01
Population growth and unpredictable climate changes will pose high demands on water resources in the future. Even at present, surface water is certainly not enough to cope with the water requirement for agricultural, industrial, recreational and drinking purposes. In this context, the usage of ground water has become essential, therefore, their quality and quantity has to be carefully managed. Regarding quantity, artificial recharge can guarantee a sustainable level of ground water, whilst the strict quality control of the waters intended for recharge will minimize contamination of both the ground water and aquifer area. However, all water resources in the planet are threatened by multiple sources of contamination coming from the extended use of chemicals worldwide. In this respect, the environmental occurrence of organic micropollutants such as pesticides, pharmaceuticals, industrial chemicals and their metabolites has experienced fast growing interest. In this paper an overview of the priority and emerging organic micropollutants in the different source waters used for artificial aquifer recharge purposes and in the recovered water is presented. Besides, some considerations regarding fate and removal of such compounds are also addressed.
Interactions of diffuse and focused allogenic recharge in an eogenetic karst aquifer (Florida, USA)
Langston, Abigail L.; Screaton, Elizabeth J.; Martin, Jonathan B.; Bailly-Comte, Vincent
2012-06-01
The karstic upper Floridan aquifer in north-central Florida (USA) is recharged by both diffuse and allogenic recharge. To understand how recharged water moves within the aquifer, water levels and specific conductivities were monitored and slug tests were conducted in wells installed in the aquifer surrounding the Santa Fe River Sink and Rise. Results indicate that diffuse recharge does not mix rapidly within the aquifer but instead flows horizontally. Stratification may be aided by the high matrix porosity of the eogenetic karst aquifer. Purging wells for sample collection perturbed conductivity for several days, reflecting mixing of the stratified water and rendering collection of representative samples difficult. Interpretive numerical simulations suggest that diffuse recharge impacts the intrusion of allogenic water from the conduit by increasing hydraulic head in the surrounding aquifer and thereby reducing influx to the aquifer from the conduit. In turn, the increase of head within the conduits affects flow paths of diffuse recharge by moving newly recharged water vertically as the water table rises and falls. This movement may result in a broad vertical zone of dissolution at the water table above the conduit system, with thinner and more focused water-table dissolution at greater distance from the conduit.
Annotated bibliography on artificial recharge of ground water, 1955-67
Signor, Donald C.; Growitz, Douglas J.; Kam, William
1970-01-01
Artificial ground-water recharge has become more important as water use by agriculture, industry, and municipalities increases. Water management agencies are increasingly interested in potential use of recharge for pollution abatement, waste-water disposal, and re-use and reclamation of locally available supplies. Research projects and theoretical analyses of operational recharge systems show increased scientific emphasis on the practice. Overall ground-water basin management systems generally now contain considerations of artificial recharge, whether by direct or indirect methods. Artificial ground-water recharge is a means of conserving surface runoff for future use in places where it would otherwise be lost, of protecting ground-water basins from salt-water encroachment along coastal areas, and of storing and distributing imported water. The biblio-graphy emphasizes technology; however, annotations of articles on waste-water reclamation, ground-water management and ground-water basin management are included. Subjects closely related to artificial recharge, including colloidal flow through porous media, field or laboratory instrumentation, and waste disposal by deep well injection are included where they specifically relate to potential recharge problems. Where almost the same material has been published in several journals, all references are included on the assumption that some publications may be more readily available to interested persons than others. Other publications, especially those of foreign literature, provided abstracts that were used freely as time limitations precluded obtaining and annotating all materials. Abstracts taken from published sources are noted. These are: "Abstracts of North American Geology," U.S. Department of the Interior, Geological Survey; "Abstracts of Recent Published Material on Foil and Water Conservation," ARS-41 series, Agricultural F.esearch Service, U.S. Department of Agriculture; "Water and1 Water
Narayan, Sri R. (Inventor); Prakash, G.K. Surya (Inventor); Kindler, Andrew (Inventor)
2014-01-01
Embodiments include an iron-air rechargeable battery having a composite electrode including an iron electrode and a hydrogen electrode integrated therewith. An air electrode is spaced from the iron electrode and an electrolyte is provided in contact with the air electrode and the iron electrodes. Various additives and catalysts are disclosed with respect to the iron electrode, air electrode, and electrolyte for increasing battery efficiency and cycle life.
Isotope study in the Alpine karst region of Rawil (Switzerland)
International Nuclear Information System (INIS)
Schotterer, U.; Siegenthaler, U.; Oeschger, H.; Wildberger, A.; Nabholz, W.
1978-01-01
An isotope study in the karst of the high Alps in Switzerland is described. From 1973 to 1978 discharge, 3 H, delta 18 O, conductivity and temperature were measured in representative springs. The springs are influenced by snowmelt in late spring and summer, by rain in late summer and autumn, and in the winter period, when infiltration stops, by reservoir water. Since tritium in precipitation in the last years scattered irregularly in time and space, the residence time of winter baseflow (2-4 years) could not be determined very precisely. The pronounced difference in delta 18 O between several springs allowed us to estimate the difference in mean altitude of their recharge areas. (orig.) [de
Estimating Groundwater Mounding in Sloping Aquifers for Managed Aquifer Recharge.
Zlotnik, Vitaly A; Kacimov, Anvar; Al-Maktoumi, Ali
2017-11-01
Design of managed aquifer recharge (MAR) for augmentation of groundwater resources often lacks detailed data, and simple diagnostic tools for evaluation of the water table in a broad range of parameters are needed. In many large-scale MAR projects, the effect of a regional aquifer base dip cannot be ignored due to the scale of recharge sources (e.g., wadis, streams, reservoirs). However, Hantush's (1967) solution for a horizontal aquifer base is commonly used. To address sloping aquifers, a new closed-form analytical solution for water table mound accounts for the geometry and orientation of recharge sources at the land surface with respect to the aquifer base dip. The solution, based on the Dupiuit-Forchheimer approximation, Green's function method, and coordinate transformations is convenient for computing. This solution reveals important MAR traits in variance with Hantush's solution: mounding is limited in time and space; elevation of the mound is strongly affected by the dip angle; and the peak of the mound moves over time. These findings have important practical implications for assessment of various MAR scenarios, including waterlogging potential and determining proper rates of recharge. Computations are illustrated for several characteristic MAR settings. © 2017, National Ground Water Association.
International Nuclear Information System (INIS)
Walton-Day, Katherine; Poeter, Eileen
2009-01-01
Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope (δ 18 O and δ 2 H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels change the local
Walton-Day, Katherine; Poeter, Eileen
2009-01-01
Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope (δ18O and δ2H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels change the local water
Energy Technology Data Exchange (ETDEWEB)
Hosono, Takahiro, E-mail: hosono@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Ikawa, Reo, E-mail: r_ikawa@es.sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Jun, E-mail: jshimada@sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Nakano, Takanori, E-mail: nakanot@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Saito, Mitsuyo, E-mail: misaito@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Onodera, Shin-ichi, E-mail: sonodera@hiroshima-u.ac.jp [Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Lee, Kang-Kun, E-mail: kklee@snu.ac.kr [School of Earth and Environmental Science, Seoul National University, San 56-1, Shinrim-dong, Kwanak-gu, Seoul 151-747 (Korea, Republic of); Taniguchi, Makoto, E-mail: makoto@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan)
2009-04-15
The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes ({delta}D, T, {delta}{sup 15}N, {delta}{sup 18}O, {delta}{sup 34}S, and {sup 87}Sr/{sup 86}Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes ({delta}D and {delta}{sup 18}O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The {delta}{sup 34}S and {delta}{sup 15}N of SO{sub 4}{sup 2-} and NO{sub 3}{sup -} data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO{sub 4}{sup 2-} (> 30 ppm as SO{sub 4}{sup 2-}) and NO{sub 3}{sup -} (> 20 ppm as NO{sub 3}{sup -}) of groundwater. The {sup 87}Sr/{sup 86}Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.
International Nuclear Information System (INIS)
Hosono, Takahiro; Ikawa, Reo; Shimada, Jun; Nakano, Takanori; Saito, Mitsuyo; Onodera, Shin-ichi; Lee, Kang-Kun; Taniguchi, Makoto
2009-01-01
The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes (δD, T, δ 15 N, δ 18 O, δ 34 S, and 87 Sr/ 86 Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes (δD and δ 18 O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The δ 34 S and δ 15 N of SO 4 2- and NO 3 - data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO 4 2- (> 30 ppm as SO 4 2- ) and NO 3 - (> 20 ppm as NO 3 - ) of groundwater. The 87 Sr/ 86 Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.
International Nuclear Information System (INIS)
Sidauruk, P.; Syafalni; Satrio
2012-01-01
The environmental isotopes were employed to study the interaction of shallow groundwater and river along the Cisadane River and Ciliwung River in Jakarta basin. The rapid growth and development of Jakarta and its surrounding cities, coupled with increasing industrial and other business sectors have impacted on the demand of the water supply for the area. These investigations have been conducted to determine the interaction between shallow groundwater and the river. The 14 C results showed that the groundwater samples (above 40 m) which were close to the river influenced the iso-age contour of 14 C, which indicated the contributions of river water. The analysis of stable isotopes 18 O and Deuterium from the river implied that the river water from upstream to downstream was influenced by the mixing of the river water with the human activities in the upstream (the isotopic compositions becoming enriched). Further, the 18 O and Deuterium data revealed that rivers of Cisadane and Ciliwung are contributing to recharge the shallow groundwater in Jakarta, especially in the nearby river bank. In general, the quality of the shallow groundwater along the rivers is good and is suitable as fresh water resource. Due to pollution and declining water table problems in the Jakarta basin, the artificial recharge wells is shown to be a good way out to delineate the problems as indicated by pilot project conducted at Kelurahan Kramat Jati, using infiltration basin method. (author)
International Nuclear Information System (INIS)
Campbell, A.R.; Vanlandingham, R.J.; Phillips, F.M.
1992-01-01
The Rustler Fm. overlies the salt beds in Salado Fm. in which the Waste Isolation Pilot Plant is being developed. The water in the Rustler Fm. aquifers have been the subject of various studies, including stable isotopes. Lambert and Harvey note that the Rustler waters all have δD below -43% whereas the other young ground waters in the region have δD's above 41%. They conclude that the water in the Rustler is not from modern recharge but is fossil water from a past climatic regime. Chapman on the other hand concludes that waters on Carlsbad Caverns are isotopically heavier than the Rustler water due to cave evaporation, and thus the Rustler water could be from modern recharge. The two different interpretations have very different implications for the hydrological characterization of the WIPP site. In order to further study this issue the authors have collected six shallow cores from the unconsolidated sand in the vicinity of WIPP. Water was extracted from each sample by vacuum distillation. For these samples the projected meteoric waters would have δD values in the range of -45 to -55%. This falls well within the range of the δD values for the Rustler Fm. From this the author concludes that the Rustler water could result from modern precipitation, although not from infiltration through a soil where evaporation is active. Soil waters may provide important isotopic constraints on the origins of water in regional aquifer systems
Probabilistic Analysis of Rechargeable Batteries in a Photovoltaic Power Supply System
Energy Technology Data Exchange (ETDEWEB)
Barney, P.; Ingersoll, D.; Jungst, R.; O' Gorman, C.; Paez, T.L.; Urbina, A.
1998-11-24
We developed a model for the probabilistic behavior of a rechargeable battery acting as the energy storage component in a photovoltaic power supply system. Stochastic and deterministic models are created to simulate the behavior of the system component;. The components are the solar resource, the photovoltaic power supply system, the rechargeable battery, and a load. Artificial neural networks are incorporated into the model of the rechargeable battery to simulate damage that occurs during deep discharge cycles. The equations governing system behavior are combined into one set and solved simultaneously in the Monte Carlo framework to evaluate the probabilistic character of measures of battery behavior.
2013-09-11
... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size DATES: The meeting...
2013-03-13
... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting...
2012-07-02
... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes. SUMMARY... 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Sizes. DATES: The meeting will...
2013-01-31
... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal... Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY... Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size. DATES: The meeting...
Nyoman Suwartha; Resky Pramadin
2012-01-01
The UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surface water is collected from recha...
PEMETAAN DATA RECHARGE AIR TANAH DI KABUPATEN SLEMAN BERDASARKAN DATA CURAH HUJAN
Directory of Open Access Journals (Sweden)
Bambang Yuwono
2017-01-01
The method used in this research is the Water Balance (keseimbangan airmethod. This method is based on any incoming rain water will be equal to the output evapotranspiration and runoff hereinafter this method is applied in the application. Factors affecting groundwater recharge the water balance method is precipitation, evapotranspiration and run off. Information og groundwater recharge is also displayed on the map using Google Map function are related to the database system to produce informative mapsCalculation of groundwater recharge is applied to the daily rainfall data input into the application which then included in the water balance equation method so it can be easy to determine the value of groundwater recharge. Groundwater recharge information can be displayed in the form of mapping, making them easier to understand visually.Based on testing, the highest recharge results of this research on the Kemput station is 1119,5 mm/year with rainfall of 2750 mm/year. Seyegan and Bronggang station is 1026,25 mm/year with rainfall of 2625 mm/year. Angin-angin and Prumpung station is 933 mm/year with rainfall of 2500 mm/year. Beran and Gemawang station is 839.5 mm/year with rainfall of 2375 mm/year. Plataran station is 808.42 mm/year with rainfall of 2333 mm/year. Godean station is 699.5 mm/year with rainfall of 2187 mm/year and the lowest at Tirto Tanjungand Santan stastion 560 mm / year with rainfall of 2000 mm / year.
Jiménez-Martínez, Joaquín; Candela, Lucila; Molinero, Jorge; Tamoh, Karim
2010-12-01
For semi-arid regions, methods of assessing aquifer recharge usually consider the potential evapotranspiration. Actual evapotranspiration rates can be below potential rates for long periods of time, even in irrigated systems. Accurate estimations of aquifer recharge in semi-arid areas under irrigated agriculture are essential for sustainable water-resources management. A method to estimate aquifer recharge from irrigated farmland has been tested. The water-balance-modelling approach was based on VisualBALAN v. 2.0, a computer code that simulates water balance in the soil, vadose zone and aquifer. The study was carried out in the Campo de Cartagena (SE Spain) in the period 1999-2008 for three different groups of crops: annual row crops (lettuce and melon), perennial vegetables (artichoke) and fruit trees (citrus). Computed mean-annual-recharge values (from irrigation+precipitation) during the study period were 397 mm for annual row crops, 201 mm for perennial vegetables and 194 mm for fruit trees: 31.4, 20.7 and 20.5% of the total applied water, respectively. The effects of rainfall events on the final recharge were clearly observed, due to the continuously high water content in soil which facilitated the infiltration process. A sensitivity analysis to assess the reliability and uncertainty of recharge estimations was carried out.
Silt and gas accumulation beneath an artificial recharge spreading basin, Southwestern Utah, U.S.A.
Heilweil, V.M.; Solomon, D.K.; Ortiz, G.
2009-01-01
Sand Hollow Reservoir in southwestern Utah, USA, is operated for both surface-water storage and artificial recharge to the underlying Navajo Sandstone. The total volume of estimated artificial recharge between 2002 and 2007 is 85 million cubic meters (69,000 acre-feet). Since 2002, artificial recharge rates have generally been declining and are inversely correlated with the increasing surface area of the reservoir. Permeability testing of core samples retrieved from beneath the reservoir indicates that this decline may not be due to silt accumulation. Artificial recharge rates also show much seasonal variability. Calculations of apparent intrinsic permeability show that these variations can only partly be explained by variation in water viscosity associated with seasonal changes in water temperature. Sporadic seasonal trends in recharge rates and intrinsic permeability during 2002-2004 could be associated with the large fluctuations in reservoir elevation and wetted area. From 2005 through 2007, the reservoir was mostly full and there has been a more consistent seasonal pattern of minimum recharge rates during the summer and maximum rates during the autumn. Total dissolved-gas pressure measurements indicate the presence of biogenic gas bubbles in the shallow sediments beneath the shallower parts of Sand Hollow Reservoir when the water is warmer. Permeability reduction associated with this gas clogging may contribute to the decrease in artificial recharge rates during the spring and summer, with a subsequently increasing recharge rates in the autumn associated with a decline in volume of gas bubbles. Other possible causes for seasonal variation in artificial recharge rates require further investigation.
A hydrochemical and isotopic case study around a near surface radioactive waste disposal
International Nuclear Information System (INIS)
Szanto, Zs.; Svingor, E.; Futo, I.; Palcsu, L.; Molnar, M.; Rinyu, L.
2007-01-01
As part of the site characterisation program for the near surface radioactive waste treatment and disposal facility (RWTDF) at Puespoekszilagy, Hungary, water quality and environmental isotope investigations have been carried out. Water samples for major ion chemistry, tritium, 14 C and stable isotope ratio measurements (δ 18 O, δD, δ 34 S, δ 13 C) were taken quarterly from the observation wells, the streams and the precipitation during the period 1999-2001. The chemical composition of groundwaters presented a continuous transition from waters situated on one side to waters on the top and on the other slope of the disposal suggesting the mixing of the three hydrochemical ''endmembers''. Most of δD and δ 18 O data were situated between GMWL and LMWL (δD = 7.2 x δ 18 O - 1 permille) with Oligocene aquifer presenting recharge of Pleistocene origin and water on the top and the gentle slope of the hill presenting recharge of Holocene origin. δ 34 S values of dissolved sulphates varied in a wide range (-14.2 permille to +5.4 permille). The tritium in precipitation varied between 4.4 and 18.1 TU with an annual weighted average of 10 ± 0.3 TU. The streams showed larger fluctuations than the wells, but the changes of δ 18 O, δD and T were small compared to those in precipitation (showing seasonal variation). Stable isotope, tritium and radiocarbon data proved that the replenishment of groundwater is slow on the steeper side and the direction of water movement is toward the gentle slope of the hill. It was judged that this path is the one that is most likely to give rise to high doses and, therefore, was used in the hydrological modelling of the safety assessment that followed the present work. The possibility that there may also be transport through the unsaturated zone and systems of perched water tables in layers 1 and 2 to both the Szilagyi and Nemedi streams cannot be excluded; the transport along these pathways is likely to be intermittent. (orig.)
On Evaluation of Recharge Model Uncertainty: a Priori and a Posteriori
International Nuclear Information System (INIS)
Ming Ye; Karl Pohlmann; Jenny Chapman; David Shafer
2006-01-01
Hydrologic environments are open and complex, rendering them prone to multiple interpretations and mathematical descriptions. Hydrologic analyses typically rely on a single conceptual-mathematical model, which ignores conceptual model uncertainty and may result in bias in predictions and under-estimation of predictive uncertainty. This study is to assess conceptual model uncertainty residing in five recharge models developed to date by different researchers based on different theories for Nevada and Death Valley area, CA. A recently developed statistical method, Maximum Likelihood Bayesian Model Averaging (MLBMA), is utilized for this analysis. In a Bayesian framework, the recharge model uncertainty is assessed, a priori, using expert judgments collected through an expert elicitation in the form of prior probabilities of the models. The uncertainty is then evaluated, a posteriori, by updating the prior probabilities to estimate posterior model probability. The updating is conducted through maximum likelihood inverse modeling by calibrating the Death Valley Regional Flow System (DVRFS) model corresponding to each recharge model against observations of head and flow. Calibration results of DVRFS for the five recharge models are used to estimate three information criteria (AIC, BIC, and KIC) used to rank and discriminate these models. Posterior probabilities of the five recharge models, evaluated using KIC, are used as weights to average head predictions, which gives posterior mean and variance. The posterior quantities incorporate both parametric and conceptual model uncertainties
Using isotope techniques to assess groundwater resources in the upper Jezireh region
International Nuclear Information System (INIS)
Kattan, Z.; Abou Zakhem, B.; Al-Charideh, A.; Kadkoy, N
2008-07-01
This work discuses in details the hydrochemical and environmental isotopes ( 2 H, 3 H, 13 C, 14 C, 18 O and 34 S) characteristics of groundwaters resources in the Palaeogene aquifer in the Upper Syrian Jezireh Region in order to evaluate these resources in terms of recharge zones and water ages in such an aquifer system that undergone during the last decades to intensive exploitation as a consequence of sever pumping in both Syria and Turkey. The results show that the main recharge zones for the Palaeogene aquifer exists in Turkey within lands of more than 700 m.a.s.l, and effectively coincide well with the exposure of the Karstified Nummulitic limestone in Mardin uplift. The chemical and isotopic behaviors of groundwaters, together with the radiometric 14 C ages reflect the existence of three different groundwater groups: (1) the fresh and cold water, percolating in short and shallow flow paths, such as the case of the major cold springs in Ras Al-Ain and Ain El-Arous areas and most wells located in the vicinity of the Syrian-Turkish borders, for which the main replenishment processes were occurred after the palaeoclimatic humid conditions of the Holocene period, placed between 4.5-6 ka BP; (2) the brackish and thermal waters containing certain amounts of H 2 S gas, that percolate in longer and deeper flow paths, for which the main replenishment processes were occurred during the palaeoclimatic humid conditions of the Pleistocene time, placed at 9-18 ka BP; (3) the brackish and admixed thermal groundwaters with intermediate 14 C ages, which seem to be formed as a result of mixing between the previous two groups. (Authors)
2012-02-14
... 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size AGENCY: Federal... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. SUMMARY: The FAA..., Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. DATES: The meeting will be held...
Energy Technology Data Exchange (ETDEWEB)
Martinez, D. E.; Quiroz Londono, O. M. [Instituto de Geologia de Costas y del Cuaternario, U.N. de Mar del Plata and Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET, Buenos Aires (Argentina); Bocanegra, E.; Massone, H. E. [Instituto de Geologia de Costas y del Cuaternario, U.N. de Mar del Plata (Argentina); Dapena, C. [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET, Buenos Aires (Argentina)
2013-07-15
A sedimentary sequence of loess-like Quaternary deposits, with a thickness ranging from a few metres to about 100 m, covers about 1 500 000 km{sup 2} in the Argentine Pampas. These deposits, named the Pampeano Sediments, constitute the main groundwater resource for the sustainability of agricultural production in Argentina. An isotope hydrology survey was carried out on a catchment area of about 10 000 km{sup 2} covered by these sediments in order to improve the understanding of the hydrological cycle. Since 2005, stable isotopes ({sup 2}H, {sup 18}O) have been determined in: (a) rainwater collected at three points in the basin; (b) stream water continuously sampled weekly at three points in the main river; and (c) groundwater samples. Furthermore, {sup 3}H concentration was determined in nearly 50 samples. Results show a seasonal effect in precipitation and the weighted average values as characteristic recharge water. A numerical flow model using the code MODFLOW was developed simultaneously and the isotopic results used to validate it. Groundwater is homogenous in its isotope composition indicating a dispersive flow model. Dominance of baseflow in the streamflow composition is another conclusion of the study. (author)
2012-04-05
... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size AGENCY: Federal... Committee 225, Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. SUMMARY: The FAA..., Rechargeable Lithium Batteries and Battery Systems, Small and Medium Size. DATES: The meeting will be held May...
A Rechargeable Hydrogen Battery.
Christudas Dargily, Neethu; Thimmappa, Ravikumar; Manzoor Bhat, Zahid; Devendrachari, Mruthunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Gautam, Manu; Shafi, Shahid Pottachola; Thotiyl, Musthafa Ottakam
2018-04-27
We utilize proton-coupled electron transfer in hydrogen storage molecules to unlock a rechargeable battery chemistry based on the cleanest chemical energy carrier molecule, hydrogen. Electrochemical, spectroscopic, and spectroelectrochemical analyses evidence the participation of protons during charge-discharge chemistry and extended cycling. In an era of anthropogenic global climate change and paramount pollution, a battery concept based on a virtually nonpolluting energy carrier molecule demonstrates distinct progress in the sustainable energy landscape.
Directory of Open Access Journals (Sweden)
S. Eeman
2012-10-01
Full Text Available In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens
Groundwater Recharge, Evapotranspiration and Surface Runoff ...
African Journals Online (AJOL)
Bheema
Using WetSpass Modeling Method in Illala Catchment, Northern Ethiopia ... Recharge is estimated by chloride ion mass balance method, empirical method, ..... environmental conditions of the catchment by applying some soil and water ... meteorological data in Ethiopia: Journal of engineers and architects, Addis Ababa,.
Separation unit for uranium isotopes etc
International Nuclear Information System (INIS)
1975-01-01
The task of the invention - improving the efficiency of a uranium isotope separation unit with a rotor as separation chamber by improving its flow characteristics - is solved by a central-axial gas conduction system with radial branches which leads the media into the separation chambers or out of these. (UWI) [de
Hydrogeochemistry and Stable Isotope Studies of Groundwater in the Ga West Municipal Area, Ghana
International Nuclear Information System (INIS)
Saka, David
2011-07-01
This study assesses groundwater in the Ga West Municipal Area of Ghana using hydrogeochemistry and stable isotope approaches. High salinity groundwaters are obtained in the municipality which poses problems for current and future domestic water supply exploitation. The increase in salinity is related to the dissolution of minerals in the host rocks and the evaporative concentration of solutes. The dominant groundwater composition in both shallow and deep wells sampled is Na-Cl, with concentration increasing substantially with well depths. The mixing process between freshwater and saline water was observed in the shift from CaHCO3 facies to Ca-Cl facies. Schoeller diagrams showed that groundwater movement in the study area is mostly vertical, moving from the shallow groundwaters towards the deep groundwaters. There were however few exceptions where no relationship was established between the shallow and the deep groundwaters. The oxygen and hydrogen isotope compositions in the groundwater samples suggest that groundwater recharge is of meteoric origin, with few samples showing evidence of evaporation. An average deuterium excess of rainfall of 14.2‰ was observed, which indicates the significance of kinetic evaporation due to low humidity conditions prevalent in the study area. The d-excess also indicates modern recharge along the Akwapim-Togo Ranges. Groundwater analysis for trace metals indicates that 93% of the groundwaters have Iron concentration above recommended limits. However, Cu, Zn, Pb, Cd and Cr have values within the acceptable limits. Generally, about 40% of the groundwaters sampled are not suitable for drinking and domestic purposes based on comparison with international standards for drinking water. (au)