Long-period Ground Motion Simulation in the Osaka Basin during the 2011 Great Tohoku Earthquake

Science.gov (United States)

Iwata, T.; Kubo, H.; Asano, K.; Sato, K.; Aoi, S.

2014-12-01

Large amplitude long-period ground motions (1-10s) with long duration were observed in the Osaka sedimentary basin during the 2011 Tohoku earthquake (Mw9.0) and its aftershock (Ibaraki-Oki, Mw7.7), which is about 600 km away from the source regions. Sato et al. (2013) analyzed strong ground motion records from the source region to the Osaka basin and showed the following characteristics. (1) In the period range of 1 to 10s, the amplitude of horizontal components of the ground motion at the site-specific period is amplified in the Osaka basin sites. The predominant period is about 7s in the bay area where the largest pSv were observed. (2) The velocity Fourier amplitude spectra with their predominant period of around 7s are observed at the bedrock sites surrounding the Osaka basin. Those characteristics were observed during both of the mainshock and the largest aftershock. Therefore, large long-period ground motions in the Osaka basin are generated by the combination of propagation-path and basin effects. They simulated ground motions due to the largest aftershock as a simple point source model using three-dimensional FDM (GMS; Aoi and Fujiwara, 1999). They used a three-dimensional velocity structure based on the Japan Integrated Velocity Structure Model (JIVSM, Koketsu et al., 2012), with the minimum effective period of the computation of 3s. Their simulation result reproduced the observation characteristics well and it validates the applicability of the JIVSM for the long period ground motion simulation. In this study, we try to simulate long-period ground motions during the mainshock. The source model we used for the simulation is based on the SMGA model obtained by Asano and Iwata (2012). We succeed to simulate long-period ground motion propagation from Kanto area to the Osaka basin fairly well. The long-period ground motion simulations with the several Osaka basin velocity structure models are done for improving the model applicability. We used strong motion

2.5D Simulation of basin-edge effects on the ground motion ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

The effects of basin-edge and soil velocity on the ground motion characteristics have been simulated ... Figure 1. 3-D and 2.5-D radial, transverse and vertical components of the radiation for .... sedimentary basin deserve a particular attention.

Guidelines for acceptable soil concentrations in the Old F- and H-Area Retention Basins. Revision 1

International Nuclear Information System (INIS)

Hamby, D.M.

1994-01-01

Concentration guidelines for residual radionuclides in soil at the sites of the Old F- and a Retention Basins (281-3F, 281-3H) have been calculated using a dose-based approach. The guidelines also are being applied to areas around the F-Basin's Process Line. Estimation of these soil guidelines was completed using RESRAD 5.0 in accordance with the DOE RESRAD methodology specified in DOE/CH/8901 (Gi89). Guidelines are provided for the nuclides known to be present in the soils at each basin (Sc87). Soil and hydrologic characteristics specific to each basin are defined for the areas above, within, and beneath the contaminated zones

Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

Directory of Open Access Journals (Sweden)

Y. Jun Xu

2013-04-01

Full Text Available Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004 river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen, nitrate + nitrite nitrogen (NO3 + NO2, total phosphorous (TP, and total organic carbon (TOC through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB acted as a significant sink for TKN (annual retention: 24%, TP (41%, and TOC (12%, but a source for NO3 + NO2 nitrogen (6%. On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise.

Different scale land subsidence and ground fissure monitoring with multiple InSAR techniques over Fenwei basin, China

Directory of Open Access Journals (Sweden)

C. Zhao

2015-11-01

Full Text Available Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground fissure, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS InSAR method and persistent scatterers (PS InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground fissure deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground fissure region, Xi'an, China, which can be benefitial to explain the occurrence of ground fissure and the correlation between land subsidence and ground fissure.

Geology and ground-water resources of the Douglas basin, Arizona, with a section on chemical quality of the ground water

Science.gov (United States)

Coates, Donald Robert; Cushman, R.L.; Hatchett, James Lawrence

1955-01-01

The Douglas basin is part of a large northwest-trending intermontane valley, known as the Sulphur Spring Valley, which lies in southeastern Arizona, and extends into northeastern Sonora, Mexico. Maturely dissected mountains rise abruptly from long alluvial slopes and culminate in peaks 3,000 to 4,000 feet above the valley floor, Bedrock in the mountain areas confines drainage on the east and west, and an arc of low hills to the north separates the basin from the Willcox basin of the Sulphur Spring Valley. Drainage of the 1,200 square miles in the Douglas basin is southward into Mexico through Whitewater Draw. The mountains include igneous, metamorphic, and sedimentary rocks ranging in age from pre-Cambrian to Tertiary, including Paleozoic and Mesozoic sedimentary rocks that total about 10,000 feet in thickness. The older rocks have been metamorphosed, and all the bedrock has been affected by igneous intrusion, largely in Mesozoic time, and by structural movements, largely in Cenozoic time and extending into the Quaternary period. By the early part of Cenozoic time the major structural features were formed, and mountain ranges had been uplifted above the valley trough along northwest-trending fault zones. Since that time the physiographic features have resulted through erosion of the mountain blocks and the deposition, in places, of more than 2,800 feet of unconsolidated rock debris in the valley. Ground-water supplies of the Douglas basin are developed largely in the saturated zone of the valley-fill sediments. The ground water in the valley fill occurs in thin lenses and strata of sand and gravel, which are interbedded with large thicknesses of silt and day. Scattered gypsum beds and extensive caliche deposits appear at the surface and occur within the valley fill at various depths. Although the valley-fill sediments are as much as 2,800 feet thick, the uppermost 300 feet or so are the most permeable. Ground water originates as precipitation in the mountain areas

Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

Science.gov (United States)

Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

2008-01-01

Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of

Basin-edge generated Rayleigh waves in the Almaty basin and corresponding consequences for ground motion amplification

Science.gov (United States)

Pilz, Marco; Parolai, Stefano; Petrovic, Bojana; Silacheva, Natalya; Abakanov, Tanatkan; Orunbaev, Sagynbek; Moldobekov, Bolot

2018-04-01

During the past two centuries, several large earthquakes have caused extensive damages in the city of Almaty in Kazakhstan. Increasing the preparedness for future events, the definition of the optimal engineering designs for civil structures and the corresponding mitigation of earthquake risks involves the accomplishment of site response studies. To this regard, a temporary seismological network of 15 stations was installed in the city aiming at the accurate identification of local variations of site response at different locations. As the city is settled on a deep sediment-filled plain with laterally strongly varying thicknesses, bound to the south by the Tien-Shan mountain range, the city might face important site effects: large amplification and significant increase of shaking duration. In addition, surface waves in the low-frequency range around and slightly higher than the fundamental resonance frequency, which could be generated at the boundaries of the basin, can carry a large amount of energy. In turn, this will influence both the spatial distribution of the level of amplification and the temporal lengthening of ground motion significantly. For quantifying these effects, we apply complex trace analysis, which uses the instantaneous polarization characteristics of the seismic signal for separating waves arriving at a single site from different directions. In this way, secondary surface waves originating at various sites along the edge of the Almaty basin can be identified as well as their generation regions. After having assessed 1-D amplification effects with well-established techniques like the standard spectral ratio and the horizontal-to-vertical spectral ratio techniques, the results further indicate that thick layers of soft clay deposits and the 3-D structure of the basin give rise to lengthening of ground motion and high amplification values at low frequencies around 0.2 Hz. The steep structure of the sediment-bedrock interface at the southern edge

Broadband Ground Motion Reconstruction for the Kanto Basin during the 1923 Kanto Earthquake

Science.gov (United States)

Sekiguchi, Haruko; Yoshimi, Masayuki

2011-03-01

Ground motions of the 1923 Kanto Earthquake inside the Kanto Basin are numerically simulated in a wide frequency range (0-10 Hz) based on new knowledge of the earthquake's source processes, the sedimentary structure of the basin, and techniques for generating broadband source models of great earthquakes. The Kanto Earthquake remains one of the most important exemplars for ground motion prediction in Japan due to its size, faulting geometry, and location beneath the densely populated Kanto sedimentary basin. We reconstruct a broadband source model of the 1923 Kanto Earthquake from inversion results by introducing small-scale heterogeneities. The corresponding ground motions are simulated using a hybrid technique comprising the following four calculations: (1) low-frequency ground motion of the engineering basement, modeled using a finite difference method; (2) high-frequency ground motion of the engineering basement, modeled using a stochastic Green's function method; (3) total ground motion of the engineering basement (i.e. 1 + 2); and (4) ground motion at the surface in response to the total basement ground motion. We employ a recently developed three-dimensional (3D) velocity structure model of the Kanto Basin that incorporates prospecting data, microtremor observations and measurements derived from strong ground motion records. Our calculations reveal peak ground velocities (PGV) exceeding 50 cm/s in the area above the fault plane: to the south, where the fault plane is shallowest, PGV reaches 150-200 cm/s at the engineering basement and 200-250 cm/s at the surface. Intensity 7, the maximum value in the Japan Meteorological Agency's intensity scale, is calculated to have occurred widely in Sagami Bay, which corresponds well with observed house-collapse rates due to the 1923 event. The modeling reveals a pronounced forward directivity effect for the area lying above the southern, shallow part of the fault plane. The high PGV and intensity seen above the

Estimates of ground-water recharge rates for two small basins in central Nevada

International Nuclear Information System (INIS)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins, two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation, stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most reliable results are those derived from a reduced form of the chloride-ion model because they reflect integrated, basinwide processes in terms of only three measured variables: precipitation amount, precipitation chemistry, and streamflow chemistry

Functional design criteria for the 242-A evaporator and PUREX [Plutonium-Uranium Extraction] Plant condensate interim retention basin

International Nuclear Information System (INIS)

Cejka, C.C.

1990-01-01

This document contains the functional design criteria for a 26- million-gallon retention basin and 10 million gallons of temporary storage tanks. The basin and tanks will be used to store 242-A Evaporator process condensate, the Plutonium-Uranium Extraction (PUREX) Plant process distillate discharge stream, and the PUREX Plant ammonia scrubber distillate stream. Completion of the project will allow both the 242-A Evaporator and the PUREX Plant to restart. 4 refs

Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

International Nuclear Information System (INIS)

Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Gruebel, R.D.

1996-08-01

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples

Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

Energy Technology Data Exchange (ETDEWEB)

Williams, C.V.; Lockwood, G.J.; Normann, R.A. [Sandia National Labs., Albuquerque, NM (United States); Gruebel, R.D. [Tech Reps, Inc., Albuquerque, NM (United States)

1996-08-01

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Long-Term Ground-Water Levels and Transmissivity in the Blackstone River Basin, Northern Rhode Island

Science.gov (United States)

Eggleston, Jack R.; Church, Peter E.; Barbaro, Jeffrey R.

2007-01-01

Ground water provides about 7.7 million gallons per day, or 28 percent of total water use in the Rhode Island part of the Blackstone River Basin. Primary aquifers in the basin are stratified glacial deposits, composed mostly of sand and gravel along valley bottoms. The ground-water and surface-water system in the Blackstone River Basin is under stress due to population growth, out-of-basin water transfers, industrialization, and changing land-use patterns. Streamflow periodically drops below the Aquatic Base Flow standard, and ground-water withdrawals add to stress on aquatic habitat during low-flow periods. Existing hydrogeologic data were reviewed to examine historical water-level trends and to generate contour maps of water-table altitudes and transmissivity of the sand and gravel aquifer in the Blackstone River Basin in Rhode Island. On the basis of data from four long-term observation wells, water levels appear to have risen slightly in the study area during the past 55 years. Analysis of available data indicates that increased rainfall during the same period is a likely contributor to the water-level rise. Spatial patterns of transmissivity are shown over larger areas and have been refined on the basis of more detailed data coverage as compared to previous mapping studies.

Ground-water availability from surficial aquifers in the Red River of the North Basin, Minnesota

Science.gov (United States)

Reppe, Thomas H.C.

2005-01-01

Population growth and commercial and industrial development in the Red River of the North Basin in Minnesota, North Dakota, and South Dakota have prompted the Bureau of Reclamation, U.S. Department of the Interior, to evaluate sources of water to sustain this growth. Nine surficial-glacial (surficial) aquifers (Buffalo, Middle River, Two Rivers, Beach Ridges, Pelican River, Otter Tail, Wadena, Pineland Sands, and Bemidji-Bagley) within the Minnesota part of the basin were identified and evaluated for their ground-water resources. Information was compiled and summarized from published studies to evaluate the availability of ground water. Published information reviewed for each of the aquifers included location and extent, physical characteristics, hydraulic properties, ground-water and surface-water interactions, estimates of water budgets (sources of recharge and discharge) and aquifer storage, theoretical well yields and actual ground-water pumping data, recent (2003) ground-water use data, and baseline ground-water-quality data.

Availability of ground water in the lower Pawcatuck River basin, Rhode Island

Science.gov (United States)

Gonthier, Joseph B.; Johnston, Herbert E.; Malmberg, Glenn T.

1974-01-01

The lower Pawcatuck River basin in southwestern Rhode Island is an area of about 169 square miles underlain by crystalline bedrock over which lies a relatively thin mantle of glacial till and stratified drift. Stratified drift, consisting dominantly of sand and gravel, occurs in irregularly shaped linear deposits that are generally less than a mile wide and less than 125 feet thick; these deposits are found along the Pawcatuck River, its tributaries, and abandoned preglacial channels. Deposits of stratified sand and gravel constitute the principal aquifer in the lower Pawcatuck basin and the only one capable of sustaining yields of 100 gallons per minute or more to individual wells. Water available for development in this aquifer consists of water in storage--potential ground-water runoff to streams--plus infiltration that can be induced from streams. Minimum annual ground-water runoff from the sand and gravel aquifer is calculated to be at least 1.17 cubic feet per second per square mile, or 0.76 million gallons per day per square mile. Potential recharge by induced infiltration is estimated to range from about 250 to 600 gallons per day per linear foot of streambed for the principal streams. In most areas, induced infiltration from streams constitutes the major source of water potentially available for development by wells. Because subsurface hydraulic connection in the sand and gravel aquifer is poor in several places, the deposits are conveniently divisible into several ground-water reservoirs. The potential yield from five of the most promising ground-water reservoirs is evaluated by means of mathematical models. Results indicate that continuous withdrawals ranging from 1.3 to 10.3 million gallons per day, and totaling 31 million gallons per day, are obtainable from these reservoirs. Larger yields may be recovered by different well placement, spacing, construction and development, pumping practice, and so forth. Withdrawals at the rates indicated will reduce

Predicting Multiple Functions of Sustainable Flood Retention Basins under Uncertainty via Multi-Instance Multi-Label Learning

Directory of Open Access Journals (Sweden)

Qinli Yang

2015-03-01

Full Text Available The ambiguity of diverse functions of sustainable flood retention basins (SFRBs may lead to conflict and risk in water resources planning and management. How can someone provide an intuitive yet efficient strategy to uncover and distinguish the multiple potential functions of SFRBs under uncertainty? In this study, by exploiting both input and output uncertainties of SFRBs, the authors developed a new data-driven framework to automatically predict the multiple functions of SFRBs by using multi-instance multi-label (MIML learning. A total of 372 sustainable flood retention basins, characterized by 40 variables associated with confidence levels, were surveyed in Scotland, UK. A Gaussian model with Monte Carlo sampling was used to capture the variability of variables (i.e., input uncertainty, and the MIML-support vector machine (SVM algorithm was subsequently applied to predict the potential functions of SFRBs that have not yet been assessed, allowing for one basin belonging to different types (i.e., output uncertainty. Experiments demonstrated that the proposed approach enables effective automatic prediction of the potential functions of SFRBs (e.g., accuracy >93%. The findings suggest that the functional uncertainty of SFRBs under investigation can be better assessed in a more comprehensive and cost-effective way, and the proposed data-driven approach provides a promising method of doing so for water resources management.

Remedial technology and characterization development at the SRS F/H Retention Basins using the DOE SAFER methodology

International Nuclear Information System (INIS)

Miles, W.C. Jr.; Kuelske, K.J.

1994-01-01

The Streamlined Approach For Environmental Restoration (SAFER) is a strategy used to accelerate and improve the environmental assessment and remediation of the F/H Retention Basins at the Savannah River Site (SRS). TMs strategy combines the data quality objectives (DQO) process and the observational approach to focus on data collection and converge on a remedial action early. This approach emphasizes stakeholder involvement throughout the Remedial Investigation/Feasibility Study (RI/FS) process. The SAFER methodology is being applied to the characterization, technology development, and remediation tasks for the F/H Retention Basins. This ''approach was initiated in the scoping phase of these projects through the involvment of major stakeholders; Department of Energy (DOE)-Savannah River Field Office, DOE-Headquarters, Westinghouse Savannah River Company, United States Environmental Protection Agency (EPA) Region IV, and the state of South Carolina Department of Health and Environmental Control (SCDHEC), in the development of the Remedial Investigation (RI) workplans. A major activity that has been initiated is the development and implementation of a phase I workplan to identify preliminary contaminants of concern (pCOCs). A sampling plan was developed and approved by the major stakeholders for preliminary characterization of wastes remaining in the F/H Retention Basins. The involvement of stakeholders, development of a site conceptual model, development of remedial objectives for probable conditions, identification of the problem and reasonable deviations, and development of initial decision rules in the planning stages will ensure that preliminary data needs are identified and obtained prior to the initiation of the assessment and implementation phases of the projects resulting in the final remediation of the sites in an accelerated and more cost effective manner

Evaluation of baseline ground-water conditions in the Mosteiros, Ribeira Paul, and Ribeira Fajã Basins, Republic of Cape Verde, West Africa, 2005-06

Science.gov (United States)

Heilweil, Victor M.; Earle, John D.; Cederberg, Jay R.; Messer, Mickey M.; Jorgensen, Brent E.; Verstraeten, Ingrid M.; Moura, Miguel A.; Querido, Arrigo; Spencer,; Osorio, Tatiana

2006-01-01

This report documents current (2005-06) baseline ground-water conditions in three basins within the West African Republic of Cape Verde (Mosteiros on Fogo, Ribeira Paul on Santo Antão, and Ribeira Fajã on São Nicolau) based on existing data and additional data collected during this study. Ground-water conditions (indicators) include ground-water levels, ground-water recharge altitude, ground-water discharge amounts, ground-water age (residence time), and ground-water quality. These indicators are needed to evaluate (1) long-term changes in ground-water resources or water quality caused by planned ground-water development associated with agricultural projects in these basins, and (2) the feasibility of artificial recharge as a mitigation strategy to offset the potentially declining water levels associated with increased ground-water development.Ground-water levels in all three basins vary from less than a few meters to more than 170 meters below land surface. Continuous recorder and electric tape measurements at three monitoring wells (one per basin) showed variations between August 2005 and June 2006 of as much as 1.8 meters. Few historical water-level data were available for the Mosteiros or Ribeira Paul Basins. Historical records from Ribeira Fajã indicate very large ground-water declines during the 1980s and early 1990s, associated with dewatering of the Galleria Fajã tunnel. More-recent data indicate that ground-water levels in Ribeira Fajã have reached a new equilibrium, remaining fairly constant since the late 1990s.Because of the scarcity of observation wells within each basin, water-level data were combined with other techniques to evaluate ground-water conditions. These techniques include the quantification of ground-water discharge (well withdrawals, spring discharge, seepage to springs, and gallery drainage), field water-quality measurements, and the use of environmental tracers to evaluate sources of aquifer recharge, flow paths, and ground

Estimates of ground-water recharge rates for two small basins in central Nevada

Science.gov (United States)

Lichty, R.W.; McKinley, P.W.

1995-01-01

Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins. two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. The first model uses a traditional approach to quantify watershed hydrology through a precipitation-runoff modeling system that accounts for the spatial variability of hydrologic inputs, processes, and responses (outputs) using a dailycomputational time step. The second model is based on the conservative nature of the dissolved chloride ion in selected hydrologic environments, and its use as a natural tracer allows the computation of acoupled, water and chloride-ion, mass-balance system of equations to estimate available water (sum ofsurface runoff and groundwater recharge). Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most

Historical and future changes of frozen ground in the upper Yellow River Basin

Science.gov (United States)

Wang, Taihua; Yang, Dawen; Qin, Yue; Wang, Yuhan; Chen, Yun; Gao, Bing; Yang, Hanbo

2018-03-01

Frozen ground degradation resulting from climate warming on the Tibetan Plateau has aroused wide concern in recent years. In this study, the maximum thickness of seasonally frozen ground (MTSFG) is estimated by the Stefan equation, which is validated using long-term frozen depth observations. The permafrost distribution is estimated by the temperature at the top of permafrost (TTOP) model, which is validated using borehole observations. The two models are applied to the upper Yellow River Basin (UYRB) for analyzing the spatio-temporal changes in frozen ground. The simulated results show that the areal mean MTSFG in the UYRB decreased by 3.47 cm/10 a during 1965-2014, and that approximately 23% of the permafrost in the UYRB degraded to seasonally frozen ground during the past 50 years. Using the climate data simulated by 5 General Circulation Models (GCMs) under the Representative Concentration Pathway (RCP) 4.5, the areal mean MTSFG is projected to decrease by 1.69 to 3.07 cm/10 a during 2015-2050, and approximately 40% of the permafrost in 1991-2010 is projected to degrade into seasonally frozen ground in 2031-2050. This study provides a framework to estimate the long-term changes in frozen ground based on a combination of multi-source observations at the basin scale, and this framework can be applied to other areas of the Tibetan Plateau. The estimates of frozen ground changes could provide a scientific basis for water resource management and ecological protection under the projected future climate changes in headwater regions on the Tibetan Plateau.

Final report of the environmental measurement-while-drilling-gamma ray spectrometer system technology demonstration at the Savannah River Site F-Area Retention Basin

Energy Technology Data Exchange (ETDEWEB)

Lockwood, G.J.; Normann, R.A.; Williams, C.V.

1997-08-01

The environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes passed near previously sampled vertical borehole locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRs system during drilling are compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Final report of the environmental measurement-while-drilling-gamma ray spectrometer system technology demonstration at the Savannah River Site F-Area Retention Basin

International Nuclear Information System (INIS)

Lockwood, G.J.; Normann, R.A.; Williams, C.V.

1997-08-01

The environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes passed near previously sampled vertical borehole locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRs system during drilling are compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples

First conference on ground control problems in the Illinois Coal Basin: proceedings

Energy Technology Data Exchange (ETDEWEB)

Chugh, Y. P.; Van Besien, A. [eds.

1980-06-01

The first conference on ground control problems in the Illinois Coal Basin was held at the Southern Illinois University at Carbondale, Illinois, August 22-24, 1979. Twenty-one papers from the proceedings have been entered individually into EDB; one had been entered previously from other sources. (LTN)

Hydrology of the coastal springs ground-water basin and adjacent parts of Pasco, Hernando, and Citrus Counties, Florida

Science.gov (United States)

Knochenmus, Lari A.; Yobbi, Dann K.

2001-01-01

The coastal springs in Pasco, Hernando, and Citrus Counties, Florida consist of three first-order magnitude springs and numerous smaller springs, which are points of substantial ground-water discharge from the Upper Floridan aquifer. Spring flow is proportional to the water-level altitude in the aquifer and is affected primarily by the magnitude and timing of rainfall. Ground-water levels in 206 Upper Floridan aquifer wells, and surface-water stage, flow, and specific conductance of water from springs at 10 gaging stations were measured to define the hydrologic variability (temporally and spatially) in the Coastal Springs Ground-Water Basin and adjacent parts of Pasco, Hernando, and Citrus Counties. Rainfall at 46 stations and ground-water withdrawals for three counties, were used to calculate water budgets, to evaluate long-term changes in hydrologic conditions, and to evaluate relations among the hydrologic components. Predictive equations to estimate daily spring flow were developed for eight gaging stations using regression techniques. Regression techniques included ordinary least squares and multiple linear regression techniques. The predictive equations indicate that ground-water levels in the Upper Floridan aquifer are directly related to spring flow. At tidally affected gaging stations, spring flow is inversely related to spring-pool altitude. The springs have similar seasonal flow patterns throughout the area. Water-budget analysis provided insight into the relative importance of the hydrologic components expected to influence spring flow. Four water budgets were constructed for small ground-water basins that form the Coastal Springs Ground-Water Basin. Rainfall averaged 55 inches per year and was the only source of inflow to the Basin. The pathways for outflow were evapotranspiration (34 inches per year), runoff by spring flow (8 inches per year), ground-water outflow from upward leakage (11 inches per year), and ground-water withdrawal (2 inches per year

3D Ground-Motion Simulations for Magnitude 9 Earthquakes on the Cascadia Megathrust: Sedimentary Basin Amplification, Rupture Directivity, and Ground-Motion Variability

Science.gov (United States)

Frankel, A. D.; Wirth, E. A.; Marafi, N.; Vidale, J. E.; Stephenson, W. J.

2017-12-01

We have produced broadband (0-10 Hz) synthetic seismograms for Mw 9 earthquakes on the Cascadia subduction zone by combining synthetics from 3D finite-difference simulations at low frequencies (≤ 1 Hz) and stochastic synthetics at high frequencies (≥ 1 Hz). These synthetic ground motions are being used to evaluate building response, liquefaction, and landslides, as part of the M9 Project of the University of Washington, in collaboration with the U.S. Geological Survey. The kinematic rupture model is composed of high stress drop sub-events with Mw 8, similar to those observed in the Mw 9.0 Tohoku, Japan and Mw 8.8 Maule, Chile earthquakes, superimposed on large background slip with lower slip velocities. The 3D velocity model is based on active and passive-source seismic tomography studies, seismic refraction and reflection surveys, and geologic constraints. The Seattle basin portion of the model has been validated by simulating ground motions from local earthquakes. We have completed 50 3D simulations of Mw 9 earthquakes using a variety of hypocenters, slip distributions, sub-event locations, down-dip limits of rupture, and other parameters. For sites not in deep sedimentary basins, the response spectra of the synthetics for 0.1-6.0 s are similar, on average, to the values from the BC Hydro ground motion prediction equations (GMPE). For periods of 7-10 s, the synthetic response spectra exceed these GMPE, partially due to the shallow dip of the plate interface. We find large amplification factors of 2-5 for response spectra at periods of 1-10 s for locations in the Seattle and Tacoma basins, relative to sites outside the basins. This amplification depends on the direction of incoming waves and rupture directivity. The basin amplification is caused by surface waves generated at basin edges from incoming S-waves, as well as amplification and focusing of S-waves and surface waves by the 3D basin structure. The inter-event standard deviation of response spectral

Estimates of ground-water pumpage from the Yakima River Basin aquifer system, Washington, 1960-2000

Science.gov (United States)

Vaccaro, J.J.; Sumioka, S.S.

2006-01-01

Ground-water pumpage in the Yakima River Basin, Washington, was estimated for eight categories of use for 1960-2000 as part of an investigation to assess groundwater availability in the basin. Methods used, pumpage estimates, reliability of the estimates, and a comparison with appropriated quantities are described. The eight categories of pumpage were public water supply, self-supplied domestic (exempt wells), irrigation, frost protection, livestock and dairy operations, industrial and commercial, fish and wildlife propagation, and ground-water claims. Pumpage estimates were based on methods that varied by the category and primarily represent pumpage for groundwater rights. Washington State Department of Ecology’s digital database has 2,874 active ground-water rights in the basin that can withdraw an annual quantity of about 529,231 acre-feet during dry years. Irrigation rights are for irrigation of about 129,570 acres. All but 220 of the rights were associated with well drillers’ logs, allowing for a spatial representation of the pumpage. Five-hundred and sixty of the irrigation rights were estimated to be standby/reserve rights. During this study, another 30 rights were identified that were not in the digital database. These rights can withdraw an annual quantity of about 20,969 acre-feet; about 6,700 acre-feet of these rights are near but outside the basin. In 1960, total annual pumpage in the basin, excluding standby/reserve pumpage, was about 115,776 acre-feet. By 2000, total annual pumpage was estimated to be 395,096 acre-feet, and excluding the standby/reserve rights, the total was 312,284 acre-feet. Irrigation accounts for about 60 percent of the pumpage, followed by public water supply at about 12 percent. The smallest category of pumpage was for livestock use with pumpage estimated to be 6,726 acre-feet. Total annual pumpage in 2000 was about 430 cubic feet per second, which is about 11 percent of the surface-water demand. Maximum pumpage is in July

Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

Science.gov (United States)

Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

2015-09-15

Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below

Regional ground-water flow modeling for the Paradox Basin, Utah: Second status report

International Nuclear Information System (INIS)

1986-09-01

Regional ground-water flow within the principal geohydrologic units of the Paradox Basin is evaluated by developing a conceptual model of the flow regime between the shallow aquifers, the Paradox salt and the deep-basin brine aquifers. This model is tested using a three-dimensional, finite-difference flow code. Sensitivity analyses (a limited parametric study) are conducted to define the system responses to changes in the conceptual model. The conceptual model is described in terms of its areal and vertical discretization, aquifer properties, fluid properties, and hydrologic boundary conditions. The simulated results are described with potentiometric surfaces, tables summarizing the areal and vertical volumetric flows through the principal units, and Darcy velocities at specified points. The reported work is the second stage of an ongoing evaluation of the Gisbon Dome area within the Paradox Basin as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the present conceptualization of ground-water flow to the hydrologic parameters and, to a lesser extent, the uncertainties of the present conceptualization. 20 refs., 17 figs., 9 tabs

Hydrographs Showing Ground-Water Level Changes for Selected Wells in the Lower Skagit River Basin, Washington

Science.gov (United States)

Fasser, E.T.; Julich, R.J.

2009-01-01

Hydrographs for selected wells in the Lower Skagit River basin, Washington, are presented in an interactive web-based map to illustrate monthly and seasonal changes in ground-water levels in the study area. Ground-water level data and well information were collected by the U.S. Geological Survey using standard techniques and were stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Availability of ground water in the middle Merrimack River basin, central and southern New Hampshire

Science.gov (United States)

Cotton, J.E.

1976-01-01

Sufficient amounts of water to supply single family homes are available from the bedrock aquifer nearly everywhere in the middle Merrimack River basin in central and southern New Hampshire. Relatively this and narrow, unconsolidated aquifers of sand or sand and gravel commonly capable of yielding more than 200 gallons per minute to properly located and constructed wells are found only in major stream valleys. The map provides a preliminary assessment of the availability of ground water in the basin, as determined by estimating the capability of the aquifers to store and transmit water. On the map, aquifers are rated as having high, medium, or low potential to yield water. Ground water in the middle Merrimack River basin is generally of good chemical quality. Most of it is clear and colorless, contains no suspended matter and practically no bacteria, water may be affected by land-use practices. Degradation of water quality may occur in unsewered residential and village areas, near solid-waste-disposal sites, agricultural land, and major highways. (Woodard-USGS)

Investigation of the structure and lithology of bedrock concealed by basin fill, using ground-based magnetic-field-profile data acquired in the San Rafael Basin, southeastern Arizona

Science.gov (United States)

Bultman, Mark W.

2013-01-01

Data on the Earth’s total-intensity magnetic field acquired near ground level and at measurement intervals as small as 1 m include information on the spatial distribution of nearsurface magnetic dipoles that in many cases are unique to a specific lithology. Such spatial information is expressed in the texture (physical appearance or characteristics) of the data at scales of hundreds of meters to kilometers. These magnetic textures are characterized by several descriptive statistics, their power spectrum, and their multifractal spectrum. On the basis of a graphical comparison and textural characterization, ground-based magnetic-field profile data can be used to estimate bedrock lithology concealed by as much as 100 m of basin fill in some cases, information that is especially important in assessing and exploring for concealed mineral deposits. I demonstrate that multifractal spectra of ground-based magnetic-field-profile data can be used to differentiate exposed lithologies and that the shape and position of the multifractal spectrum of the ground-based magnetic-field-profile of concealed lithologies can be matched to the upward-continued multifractal spectrum of an exposed lithology to help distinguish the concealed lithology. In addition, ground-based magnetic-field-profile data also detect minute differences in the magnetic susceptibility of rocks over small horizontal and vertical distances and so can be used for precise modeling of bedrock geometry and structure, even when that bedrock is concealed by 100 m or more of nonmagnetic basin fill. Such data contain valuable geologic information on the bedrock concealed by basin fill that may not be so visible in aeromagnetic data, including areas of hydrothermal alteration, faults, and other bedrock structures. Interpretation of these data in the San Rafael Basin, southeastern Arizona, has yielded results for estimating concealed lithologies, concealed structural geology, and a concealed potential mineral

Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

Science.gov (United States)

Tumbusch, Mary L.; Plume, Russell W.

2006-01-01

The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

Investigation for Strong Ground Shaking across the Taipei Basin during the MW 7.0 Eastern Taiwan Offshore Earthquake of 31 March 2002

Directory of Open Access Journals (Sweden)

Yi-Ling Huang

2010-01-01

Full Text Available According to reconstructed ground motion snapshots of the northern Taiwan area during the MW 7.0 eastern Taiwan offshore earthquake of 31 March 2002, the composite effects indicated complicated wave propagation behavior in the ground motion of the Taipei basin. A major low frequency pulse arose after the S-wave with the duration of about 20 seconds was observed in northern Taiwan and dominated the radial direction. Observed waveforms of a low frequency pulse show amplification during the seismic wave across the Taipei basin from its eastern edge to western portion. This effect has been considered to be generated by an unusual source radiation, deep Moho reflection or basin bottom surface. In this study, recorded ground motions from a dense seismic network were analyzed using a frequency-wavenumber spectrum analysis for seismic wave propagation properties. We investigated temporal and spatial variations in strong shaking in different frequency bands. Results show that a simple pulse incident seismic wave strongly interacts with inside soft sediments and the surrounding topography of the Taipei basin which in turn extends its shaking duration. Evidence showed that seismic waves have been reflected back from its western boundary of basin with a dominant frequency near one Hz. Findings in this study have been rarely reported and may provide useful information to further constrain a three-dimensional numerical simulation for the basin response and velocity structure, and to predict ground motions of further large earthquakes.

Retention efficiencies of halogenated and non-halogenated hydrocarbons in selected wetland ecosystem in Lake Victoria Basin

Directory of Open Access Journals (Sweden)

Shadrack Mule

2015-06-01

Full Text Available The determination of retention efficiencies of halogenated and non-halogenated hydrocarbon in selected wetland ecosystems in Lake Victoria basin was carried out. Qualitative and quantitative determination of the presence of residual hydrocarbons in Kigwal/Kimondi, Nyando and Nzoia wetland ecosystems using Gas Chromatography - Mass Spectrometer (GC-MS instrument indicated the presence of residual organochlorines, organophosphorus, carbamates and synthetic pyrethroid hydrocarbons in water, sediment and plant materials. In order to compare the retention efficiencies of the wetlands, the wetland ecosystems were divided into three different sections, namely: inlet, mid and outlet. Calculations of mass balances of residual halogenated and non-halogenated hydrocarbons at the respective sections was done taking into account the partition of the studied compounds in samples of water, sediments and papyrus reed plant materials and analyzed using validated Gas Chromatography - Mass Spectrometer (GC-MS method. From the analysis, several residual hydrocarbons namely: bendiocarb, benzene hexachloride (BHC, carbaryl, cypermethrin, decis, deltamethrin, diazinon, dieldrin, DDT, DDD, DDE, malathion, propoxur, sumithion, 5-phenylrhodanine, 1,3,5-trichlorobenzene, 1-(2-phenoxybenzylhydrazine were detected and quantified. The levels of the selected residual hydrocarbons in water samples were used to calculate the retention efficiencies of a specific hydrocarbon and the values recorded. Generally, River Nyando wetland recorded mean percentage retention efficiencies of 76 and 94% for dry and rainy seasons respectively; Kigwal/Kimondi wetland had seasonal mean percentage retention efficiencies of 63 to 78%. River Nzoia also had calculated seasonal mean percentage retention efficiencies of between 56 to 88%. Dry season had lower mean percentages retention efficiencies as compared to rainy season in the three wetlands of interest during the period of study. The study

Ground-Water System in the Chimacum Creek Basin and Surface Water/Ground Water Interaction in Chimacum and Tarboo Creeks and the Big and Little Quilcene Rivers, Eastern Jefferson County, Washington

Science.gov (United States)

Simonds, F. William; Longpre, Claire I.; Justin, Greg B.

2004-01-01

A detailed study of the ground-water system in the unconsolidated glacial deposits in the Chimacum Creek Basin and the interactions between surface water and ground water in four main drainage basins was conducted in eastern Jefferson County, Washington. The study will assist local watershed planners in assessing the status of the water resources and the potential effects of ground-water development on surface-water systems. A new surficial geologic map of the Chimacum Creek Basin and a series of hydrogeologic sections were developed by incorporating LIDAR imagery, existing map sources, and drillers' logs from 110 inventoried wells. The hydrogeologic framework outlined in the study will help characterize the occurrence of ground water in the unconsolidated glacial deposits and how it interacts with the surface-water system. Water levels measured throughout the study show that the altitude of the water table parallels the surface topography and ranges from 0 to 400 feet above the North American Vertical Datum of 1988 across the basin, and seasonal variations in precipitation due to natural cycles generally are on the order of 2 to 3 feet. Synoptic stream-discharge measurements and instream mini-piezometers and piezometers with nested temperature sensors provided additional data to refine the positions of gaining and losing reaches and delineate seasonal variations. Chimacum Creek generally gains water from the shallow ground-water system, except near the community of Chimacum where localized losses occur. In the lower portions of Chimacum Creek, gaining conditions dominate in the summer when creek stages are low and ground-water levels are high, and losing conditions dominate in the winter when creek stages are high relative to ground-water levels. In the Quilcene Bay area, three drainage basins were studied specifically to assess surface water/ground water interactions. The upper reaches of Tarboo Creek generally gain water from the shallow ground-water system

Ground Motion Prediction for Great Interplate Earthquakes in Kanto Basin Considering Variation of Source Parameters

Science.gov (United States)

Sekiguchi, H.; Yoshimi, M.; Horikawa, H.

2011-12-01

Broadband ground motions are estimated in the Kanto sedimentary basin which holds Tokyo metropolitan area inside for anticipated great interplate earthquakes along surrounding plate boundaries. Possible scenarios of great earthquakes along Sagami trough are modeled combining characteristic properties of the source area and adequate variation in source parameters in order to evaluate possible ground motion variation due to next Kanto earthquake. South to the rupture area of the 2011 Tohoku earthquake along the Japan trench, we consider possible M8 earthquake. The ground motions are computed with a four-step hybrid technique. We first calculate low-frequency ground motions at the engineering basement. We then calculate higher-frequency ground motions at the same position, and combine the lower- and higher-frequency motions using a matched filter. We finally calculate ground motions at the surface by computing the response of the alluvium-diluvium layers to the combined motions at the engineering basement.

Ground-Water Quality Data in the Coastal Los Angeles Basin Study Unit, 2006: Results from the California GAMA Program

Science.gov (United States)

Mathany, Timothy M.; Land, Michael; Belitz, Kenneth

2008-01-01

Ground-water quality in the approximately 860 square-mile Coastal Los Angeles Basin study unit (CLAB) was investigated from June to November of 2006 as part of the Statewide Basin Assessment Project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment was developed in response to the Ground-Water Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Coastal Los Angeles Basin study was designed to provide a spatially unbiased assessment of raw ground-water quality within CLAB, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 69 wells in Los Angeles and Orange Counties. Fifty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (?grid wells?). Fourteen additional wells were selected to evaluate changes in ground-water chemistry or to gain a greater understanding of the ground-water quality within a specific portion of the Coastal Los Angeles Basin study unit ('understanding wells'). Ground-water samples were analyzed for: a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides, polar pesticides, and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicators]; constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), 1,4-dioxane, and 1,2,3-trichloropropane (1,2,3-TCP)]; inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements]; radioactive constituents [gross-alpha and gross-beta radiation, radium isotopes, and radon-222]; and microbial indicators. Naturally occurring isotopes [stable isotopic ratios of hydrogen and oxygen, and activities of tritium and carbon-14

Ground Motions Simulations and Site Effects in the Quito Basin (Ecuador)

Science.gov (United States)

Courboulex, F.; Castro-Cruz, D.; Laurendeau, A.; Bonilla, L. F.; Bertrand, E.; Mercerat, D.; Alvarado, A. P.

2017-12-01

The city of Quito (3M inhabitants), capital of Ecuador has been damaged several times in the past by large earthquakes. It is built on the hanging-wall of an active reverse fault, constituting a piggy-back basin. The deep structure of this basin and its seismic response remains badly known. We first use the recordings of 170 events on 18 accelerometers from the Quito permanent network and perform spectral ratio analysis. We find that the southern part of Quito shows strong site amplification at low frequency ( 0.35 Hz). Yet, high frequency ( 5 Hz) amplifications also exist, but exhibit a complex spatial variability. We then propose a new calibrated method based on empirical Green's functions (EGF) to simulate the ground motions due to a future earthquake in Quito. The idea is to use the results of a global database of source time functions (i.e., the SCARDEC database, Vallée and Douet, 2016; Courboulex et al., 2016) to define the average values and the variability of the stress-drop ratio parameter, which strongly affects the resulting simulations. We test the method on a Mw 7.8 event, similar in location and focal mechanism to the Pedernales earthquake that occurred on April 16th 2016 on the subduction zone. For this aim, we use the recordings of 6 aftershocks of magnitude 5.6 to 6.2 as EGF's. The predicted Fourier spectra, peak values and response spectra we obtain are in good agreement with real data from the 2016 event recorded on the Quito network. With the constraints we impose on stress-drop ratios, we expect that the simulated ground motions be representative of the variability of other Pedernales-type events that could occur in the future. Our results also well reproduce the low frequency site effects amplification in the south of the basin. This amplification could be particularly dangerous in the case of a mega subduction earthquake, like the one that struck Ecuador in 1906.

Second status report on regional ground-water flow modeling for the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

1986-07-01

Regional ground-water flow within the principal geohydrologic units of the Palo Duro Basin is evaluated by developing a conceptual model of the flow regime and testing the model using a three-dimensional, finite-difference flow code. Sensitivity analyses (a limited parametric study) are conducted to define the system responses to changes in the conceptual model. Of particular interest are the impacts of salt permeability and potential climatic changes on the system response. The conceptual model is described in terms of its areal and vertical discretization, aquifer properties, fluid properties and hydrologic boundary conditions. The simulated ground-water flow fields are described with potentiometric surfaces, tables summarizing the areal and vertical volumetric flows through the principal units, and Darcy velocities within specified finite-difference blocks. The reported work is the second stage of an ongoing evaluation of the Palo Duro Basin as a potential repository for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, the report does provide a useful basis for describing the sensitivity of the present conceptualization of ground-water flow to particular parameters and, to a lesser extent, the uncertainties in the present conceptualization. 28 refs., 44 figs., 13 tabs

Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

Science.gov (United States)

Juckem, Paul F.

2009-01-01

A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

Arsenic, Boron, and Fluoride Concentrations in Ground Water in and Near Diabase Intrusions, Newark Basin, Southeastern Pennsylvania

Science.gov (United States)

Senior, Lisa A.; Sloto, Ronald A.

2006-01-01

During an investigation in 2000 by the U.S. Environmental Protection Agency (USEPA) of possible contaminant releases from an industrial facility on Congo Road near Gilbertsville in Berks and Montgomery Counties, southeastern Pennsylvania, concentrations of arsenic and fluoride above USEPA drinking-water standards of 10 ?g/L and 4 mg/L, respectively, and of boron above the USEPA health advisory level of 600 ?g/L were measured in ground water in an area along the northwestern edge of the Newark Basin. In 2003, the USEPA requested technical assistance from the U.S. Geological Survey (USGS) to help identify sources of arsenic, boron, and fluoride in the ground water in the Congo Road area, which included possible anthropogenic releases and naturally occurring mineralization in the local bedrock aquifer, and to identify other areas in the Newark Basin of southeastern Pennsylvania with similarly elevated concentrations of these constituents. The USGS reviewed available data and collected additional ground-water samples in the Congo Road area and four similar hydrogeologic settings. The Newark Basin is the largest of the 13 major exposed Mesozoic rift basins that stretch from Nova Scotia to South Carolina. Rocks in the Newark Basin include Triassic through Jurassic-age sedimentary sequences of sandstones and shales that were intruded by diabase. Mineral deposits of hydrothermal origin are associated with alteration zones bordering intrusions of diabase and also occur as strata-bound replacement deposits of copper and zinc in sedimentary rocks. The USGS review of data available in 2003 showed that water from about 10 percent of wells throughout the Newark Basin of southeastern Pennsylvania had concentrations of arsenic greater than the USEPA maximum contaminant level (MCL) of 10 ?g/L; the highest reported arsenic concentration was at about 70 ?g/L. Few data on boron were available, and the highest reported boron concentration in well-water samples was 60 ?g/L in contrast

Geohydrology and simulation of ground-water flow in the Red Clay Creek Basin, Chester County, Pennsylvania, and New Castle County, Delaware

Science.gov (United States)

Vogel, Karen L.; Reif, Andrew G.

1993-01-01

The 54-square-mile Red Clay Creek Basin, located in the lower Delaware River Basin, is underlain primarily by metamorphic rocks that range from Precambrian to Lower Paleozoic in age. Ground water flows through secondary openings in fractured crystalline rock and through primary openings below the water table in the overlying saprolite. Secondary porosity and permeability vary with hydrogeologic unit, topographic setting, and depth. Thirty-nine percent of the water-bearing zones are encountered within 100 feet of the land surface, and 79 percent are within 200 feet. The fractured crystalline rock and overlying saprolite act as a single aquifer under unconfined conditions. The water table is a subdued replica of the land surface. Local ground-water flow systems predominate in the basin, and natural ground-water discharge is to streams, comprising 62 to 71 percent of streamflow. Water budgets for 1988-90 for the 45-square-mile effective drainage area above the Woodale, Del., streamflow-measurement station show that annual precipitation ranged from 43.59 to 59.14 inches and averaged 49.81 inches, annual streamflow ranged from 15.35 to 26.33 inches and averaged 20.24 inches, and annual evapotranspiration ranged from 27.87 to 30.43 inches and averaged 28.98 inches. The crystalline rocks of the Red Clay Creek Basin were simulated two-dimensionally as a single aquifer under unconfined conditions. The model was calibrated for short-term steady-state conditions on November 2, 1990. Recharge was 8.32 inches per year. Values of aquifer hydraulic conductivity in hillside topographic settings ranged from 0.07 to 2.60 feet per day. Values of streambed hydraulic conductivity ranged from 0.08 to 26.0 feet per day. Prior to simulations where ground-water development was increased, the calibrated steady-state model was modified to approximate long-term average conditions in the basin. Base flow of 11.98 inches per year and a ground-water evapotranspiration rate of 2.17 inches per

Analog model study of the ground-water basin of the Upper Coachella Valley, California

Science.gov (United States)

Tyley, Stephen J.

1974-01-01

An analog model of the ground-water basin of the upper Coachella Valley was constructed to determine the effects of imported water on ground-water levels. The model was considered verified when the ground-water levels generated by the model approximated the historical change in water levels of the ground-water basin caused by man's activities for the period 1986-67. The ground-water basin was almost unaffected by man's activities until about 1945 when ground-water development caused the water levels to begin to decline. The Palm Springs area has had the largest water-level decline, 75 feet since 1986, because of large pumpage, reduced natural inflow from the San Gorgonio Pass area, and diversions of natural inflows at Snow and Falls Creeks and Chino Canyon starting in 1945. The San Gorgonio Pass inflow had been reduced from about 18,000 acre-feet in 1986 to about 9,000 acre-feet by 1967 because of increased ground-water pumpage in the San Gorgonio Pass area, dewatering of the San Gorgonio Pass area that took place when the tunnel for the Metropolitan Water District of Southern California was drilled, and diversions of surface inflow at Snow and Falls Creeks. In addition, 1944-64 was a period of below-normal precipitation which, in part, contributed to the declines in water levels in the Coachella Valley. The Desert Hot Springs, Garnet Hill, and Mission Creek subbasins have had relatively little development; consequently, the water-level declines have been small, ranging from 5 to 15 feet since 1986. In the Point Happy area a decline of about 2 feet per year continued until 1949 when delivery of Colorado River water to the lower valley through the Coachella Canal was initiated. Since 1949 the water levels in the Point Happy area have been rising and by 1967 were above their 1986 levels. The Whitewater River subbasin includes the largest aquifer in the basin, having sustained ground-water pumpage of about 740,000 acre-feet from 1986 to 1967, and will probably

First status report on regional ground-water flow modeling for the Paradox Basin, Utah

International Nuclear Information System (INIS)

Andrews, R.W.

1984-05-01

Regional ground-water flow within the principal hydrogeologic units of the Paradox Basin is evaluated by developing a conceptual model of the flow regime in the shallow aquifers and the deep-basin brine aquifers and testing these models using a three-dimensional, finite-difference flow code. Semiquantitative sensitivity analysis (a limited parametric study) is conducted to define the system response to changes in hydrologic properties or boundary conditions. A direct method for sensitivity analysis using an adjoint form of the flow equation is applied to the conceptualized flow regime in the Leadville limestone aquifer. All steps leading to the final results and conclusions are incorporated in this report. The available data utilized in this study is summarized. The specific conceptual models, defining the areal and vertical averaging of litho-logic units, aquifer properties, fluid properties, and hydrologic boundary conditions, are described in detail. Two models were evaluated in this study: a regional model encompassing the hydrogeologic units above and below the Paradox Formation/Hermosa Group and a refined scale model which incorporated only the post Paradox strata. The results are delineated by the simulated potentiometric surfaces and tables summarizing areal and vertical boundary fluxes, Darcy velocities at specific points, and ground-water travel paths. Results from the adjoint sensitivity analysis include importance functions and sensitivity coefficients, using heads or the average Darcy velocities to represent system response. The reported work is the first stage of an ongoing evaluation of the Gibson Dome area within the Paradox Basin as a potential repository for high-level radioactive wastes

Geologic framework of the regional ground-water flow system in the Upper Deschutes Basin, Oregon

Science.gov (United States)

Lite, Kenneth E.; Gannett, Marshall W.

2002-12-10

Ground water is increasingly relied upon to satisfy the needs of a growing population in the upper Deschutes Basin, Oregon. Hydrogeologic studies are being undertaken to aid in management of the ground-water resource. An understanding of the geologic factors influencing ground-water flow is basic to those investigations. The geology of the area has a direct effect on the occurrence and movement of ground water. The permeability and storage properties of rock material are influenced by the proportion, size, and degree of interconnection of open spaces the rocks contain. These properties are the result of primary geologic processes such as volcanism and sedimentation, as well as subsequent processes such as faulting, weathering, or hydrothermal alteration. The geologic landscape in the study area evolved during about 30 million years of volcanic activity related to a north-south trending volcanic arc, the current manifestation of which are today’s Cascade Range volcanoes.

Preliminary simulation model to determine ground-water flow and ages within the Palo Duro Basin hydrogeologic province

International Nuclear Information System (INIS)

Atwood, H.; Picking, L.

1986-01-01

Ground-water flow through the Palo Duro and Tucumcari Basins is simulated by developing a hydrogeolgic profile and applying a cross-sectional, finite-element, numerical model to the profile. The profile is 350 miles long and 2 miles deep and extends from east-central New Mexico to the Texas-Oklahoma border. It is comprised of hydrogeologic units that are identified from geophysical well logs, sample logs, and core descriptions. A hydrogeologic unit as used in this profile is a physically continuous rock sequence with hydrologic properties that are relatively consistent throughout and distinct from surrounding units. The resulting hydrogeologic profile, with the exception of the Ogallala Formation and the Dockum Group, is discretized into a 6000-element mesh and a 22,000-element mesh. Permeability values assigned to hydrogeologic units were, in part, calculated from drill stem tests conducted throughout the Palo Duro Basin. Ground-water age and travel paths are determined by applying Darcy's equation to selected flow lines. The 170 million-year age determined from ground-water at points within the Wolfcamp Series compares favorably with the geochemical data for this region. An age of 188 million years is determined for the Pennsylvanian granite wash

A study on uranium metallogenetic prospects of ground water oxidation zone type in the lower cretaceous, north Shanganning basin

International Nuclear Information System (INIS)

Wang Jinping

2000-01-01

Lower Cretaceous is developed well in the north part of Shanganning basin. The area was widely uplifting vertically after their deposited. Based on the features of lithology, lithophase and Neotectonic forms, two main periods of oxidation-erosion of K2-E1 and N1-present can be distinguished. During these two periods, large scale horizontal oxidation were occurred. It is significant that the ground water oxidation related to the uranium mineralization and has been proved by the field investigation and the data of γ-logging in drill hole for oil. Meanwhile, according to the hydrodynamic features of present Shanganning plateau type artesian basin, it seems that uranium mineralization main related to the ground water oxidation the upper parts of the Lower Cretaceous

Geohydrology and numerical simulation of ground-water flow in the central Virgin River basin of Iron and Washington Countries, Utah

Science.gov (United States)

Heilweil, V.M.; Freethey, G.W.; Wilkowske, C.D.; Stolp, B.J.; Wilberg, D.E.

2000-01-01

Because rapid growth of communities in Washington and Iron Counties, Utah, is expected to cause an increase in the future demand for water resources, a hydrologic investigation was done to better understand ground-water resources within the central Virgin River basin. This study focused on two of the principal ground-water reservoirs within the basin: the upper Ash Creek basin ground-water system and the Navajo and Kayenta aquifer system. The ground-water system of the upper Ash Creek drainage basin consists of three aquifers: the uppermost Quaternary basin-fill aquifer, the Tertiary alluvial-fan aquifer, and the Tertiary Pine Valley monzonite aquifer. These aquifers are naturally bounded by the Hurricane Fault and by drainage divides. On the basis of measurements, estimates, and numerical simulations of reasonable values for all inflow and outflow components, total water moving through the upper Ash Creek drainage basin ground-water system is estimated to be about 14,000 acre-feet per year. Recharge to the upper Ash Creek drainage basin ground-water system is mostly from infiltration of precipitation and seepage from ephemeral and perennial streams. The primary source of discharge is assumed to be evapotranspiration; however, subsurface discharge near Ash Creek Reservoir also may be important. The character of two of the hydrologic boundaries of the upper Ash Creek drainage basin ground-water system is speculative. The eastern boundary provided by the Hurricane Fault is assumed to be a no-flow boundary, and a substantial part of the ground-water discharge from the system is assumed to be subsurface outflow beneath Ash Creek Reservoir along the southern boundary. However, these assumptions might be incorrect because alternative numerical simulations that used different boundary conditions also proved to be feasible. The hydrogeologic character of the aquifers is uncertain because of limited data. Difference in well yield indicate that there is considerable

Long-period Ground Motion Characteristics Inside and Outside of the Osaka Basin during the 2011 Great Tohoku Earthquake and Its Largest Aftershock

Science.gov (United States)

Sato, K.; Iwata, T.; Asano, K.; Kubo, H.; Aoi, S.

2013-12-01

The 2011 great Tohoku earthquake (Mw 9.0) occurred on March 11, 2011, and the largest aftershock (Mw 7.7) at the region adjacent to south boundary of the mainshock's source region. Long-period ground motions (1-10s) of large amplitude were observed in the Osaka sedimentary basin about 550-800km away from the source regions during both events. We studied propagation and site characteristics of these ground motions, and found some common features between these two events in the Osaka basin. (1) The amplitude of horizontal components of the ground motion at the site-specific period is amplified at each sedimentary station. The predominant period is around 7s in the bayside area where the largest pSv were observed. (2) The velocity Fourier spectra have their peak values around 7s at the bedrock sites surrounding the Osaka basin. (3) Two remarkable wave packets separated by 30s propagating from stations around the Nobi plain to the bedrock sites near the Osaka basin were seen in the pasted-up velocity waveforms from the source regions to the Osaka basin for both events (Sato et al., 2012). Therefore, large long-period ground motions in the Osaka basin are generated by the combination of propagation-path and basin effects. Firstly, we simulate ground motions due to the largest aftershock using three-dimensional FDM (GMS; Aoi and Fujiwara, 1999). The reason we focus on the largest aftershock is that this event has a relatively small rupture area and simple rupture process compared to the mainshock. The source model is based on the model estimated by Kubo et al. (2013). The velocity structure model is a three-dimensional velocity structure based on the Japan Integrated Velocity Structure Model (Koketsu et al., 2012) and the layer of Vs 350m/s in this model is replaced with one of Vs 500m/s. The minimum effective period in this computation is 3s. Then, we compare synthetic waveforms with observed ones. At CHBH14, the nearest station to the source and 60km away from the

Impact of deforestation and climate on the Amazon Basin's above-ground biomass during 1993-2012.

Science.gov (United States)

Exbrayat, Jean-François; Liu, Yi Y; Williams, Mathew

2017-11-15

Since the 1960s, large-scale deforestation in the Amazon Basin has contributed to rising global CO 2 concentrations and to climate change. Recent advances in satellite observations enable estimates of gross losses of above-ground biomass (AGB) stocks due to deforestation. However, because of simultaneous regrowth, the net contribution of deforestation emissions to rising atmospheric CO 2 concentrations is poorly quantified. Climate change may also reduce the potential for forest regeneration in previously disturbed regions. Here, we address these points of uncertainty with a machine-learning approach that combines satellite observations of AGB with climate data across the Amazon Basin to reconstruct annual maps of potential AGB during 1993-2012, the above-ground C storage potential of the undisturbed landscape. We derive a 2.2 Pg C loss of AGB over the study period, and, for the regions where these losses occur, we estimate a 0.7 Pg C reduction in potential AGB. Thus, climate change has led to a decline of ~1/3 in the capacity of these disturbed forests to recover and recapture the C lost in disturbances during 1993-2012. Our approach further shows that annual variations in land use change mask the natural relationship between the El Niño/Southern Oscillation and AGB stocks in disturbed regions.

Spatiotemporal mapping of ground water pollution in a Greek lignite basin, using geostatistics

Energy Technology Data Exchange (ETDEWEB)

Modis, K. [National Technical Univ. of Athens, Athens (Greece)

2010-07-01

An issue of significant interest in the mining industry in Greece is the occurrence of chemical pollutants in ground water. Ammonium, nitrites and nitrates concentrations have been monitored through an extensive sampling network in the Ptolemais lignite opencast mining area in Greece. Due to intensive mining efforts in the area, the surface topology is continuously altered, affecting the life span of the water boreholes and resulting in messy spatiotemporal distribution of data. This paper discussed the spatiotemporal mapping of ground water pollution in the Ptolemais lignite basin, using geostatistics. More specifically, the spatiotemporal distribution of ground water contamination was examined by the application of the bayesian maximum entropy theory which allows merging spatial and temporal estimations in a single model. The paper provided a description of the site and discussed the materials and methods, including samples and statistics; variography; and spatiotemporal mapping. It was concluded that in the case of the Ptolemais mining area, results revealed an underlying average yearly variation pattern of pollutant concentrations. Inspection of the produced spatiotemporal maps demonstrated a continuous increase in the risk of ammonium contamination, while risk for the other two pollutants appeared in hot spots. 18 refs., 1 tab., 7 figs.

Spatiotemporal mapping of ground water pollution in a Greek lignite basin, using geostatistics

International Nuclear Information System (INIS)

Modis, K.

2010-01-01

An issue of significant interest in the mining industry in Greece is the occurrence of chemical pollutants in ground water. Ammonium, nitrites and nitrates concentrations have been monitored through an extensive sampling network in the Ptolemais lignite opencast mining area in Greece. Due to intensive mining efforts in the area, the surface topology is continuously altered, affecting the life span of the water boreholes and resulting in messy spatiotemporal distribution of data. This paper discussed the spatiotemporal mapping of ground water pollution in the Ptolemais lignite basin, using geostatistics. More specifically, the spatiotemporal distribution of ground water contamination was examined by the application of the bayesian maximum entropy theory which allows merging spatial and temporal estimations in a single model. The paper provided a description of the site and discussed the materials and methods, including samples and statistics; variography; and spatiotemporal mapping. It was concluded that in the case of the Ptolemais mining area, results revealed an underlying average yearly variation pattern of pollutant concentrations. Inspection of the produced spatiotemporal maps demonstrated a continuous increase in the risk of ammonium contamination, while risk for the other two pollutants appeared in hot spots. 18 refs., 1 tab., 7 figs.

Radioactive carbon-14 dating of ground waters in IPEN for evaluation of water resources in Rio Grande do Norte and Parana basin

International Nuclear Information System (INIS)

Chandra, U.; Pereira, M.C.

1986-01-01

14 C dating of deep ground waters from Potiguar basin and Parana basin was carried out to identify zones of recharge. In all 28 samples, five from Potiguar basin and 23 from Parana basin were analyzed for 14 C. The methods of sample collection and analysis are described. The analysis consists of transforming carbon of the sample to benzene, by synthesis process involving four steps i.e. production of carbon dioxide, production of lithium carbide, hydrolysis to acetylene and catalytic polymerization to bezene. The specific activity of the synthertized benzene is measured by liquid scintillation counting. The corrections for initial 14 C content have been made by using the model of Vogel. (Author) [pt

Soil Water Retention Curve

Science.gov (United States)

Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

2016-12-01

Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

Comparison between agricultural and urban ground-water quality in the Mobile River Basin

Science.gov (United States)

Robinson, James L.

2003-01-01

The Black Warrior River aquifer is a major source of public water supply in the Mobile River Basin. The aquifer outcrop trends northwest - southeast across Mississippi and Alabama. A relatively thin shallow aquifer overlies and recharges the Black Warrior River aquifer in the flood plains and terraces of the Alabama, Coosa, Black Warrior, and Tallapoosa Rivers. Ground water in the shallow aquifer and the Black Warrior River aquifer is susceptible to contamination due to the effects of land use. Ground-water quality in the shallow aquifer and the shallow subcrop of the Black Warrior River aquifer, underlying an agricultural and an urban area, is described and compared. The agricultural and urban areas are located in central Alabama in Autauga, Elmore, Lowndes, Macon, Montgomery, and Tuscaloosa Counties. Row cropping in the Mobile River Basin is concentrated within the flood plains of major rivers and their tributaries, and has been practiced in some of the fields for nearly 100 years. Major crops are cotton, corn, and beans. Crop rotation and no-till planting are practiced, and a variety of crops are grown on about one-third of the farms. Row cropping is interspersed with pasture and forested areas. In 1997, the average farm size in the agricultural area ranged from 196 to 524 acres. The urban area is located in eastern Montgomery, Alabama, where residential and commercial development overlies the shallow aquifer and subcrop of the Black Warrior River aquifer. Development of the urban area began about 1965 and continued in some areas through 1995. The average home is built on a 1/8 - to 1/4 - acre lot. Ground-water samples were collected from 29 wells in the agricultural area, 30 wells in the urban area, and a reference well located in a predominately forested area. The median depth to the screens of the agricultural and urban wells was 22.5 and 29 feet, respectively. Ground-water samples were analyzed for physical properties, major ions, nutrients, and pesticides

Radionuclides in ground water of the Carson River Basin, western Nevada and eastern California, U.S.A.

Science.gov (United States)

Thomas, J.M.; Welch, A.H.; Lico, M.S.; Hughes, J.L.; Whitney, R.

1993-01-01

Ground water is the main source of domestic and public supply in the Carson River Basin. Ground water originates as precipitation primarily in the Sierra Nevada in the western part of Carson and Eagle Valleys, and flows down gradient in the direction of the Carson River through Dayton and Churchill Valleys to a terminal sink in the Carson Desert. Because radionuclides dissolved in ground water can pose a threat to human health, the distribution and sources of several naturally occurring radionuclides that contribute to gross-alpha and gross-beta activities in the study area were investigated. Generally, alpha and beta activities and U concentration increase from the up-gradient to down-gradient hydrographic areas of the Carson River Basin, whereas 222Rn concentration decreases. Both 226Ra and 228Ra concentrations are similar throughout the study area. Alpha and beta activities and U concentration commonly exceed 100 pCi/l in the Carson Desert at the distal end of the flow system. Radon-222 commonly exceeds 2,000 pCi/l in the western part of Carson and Eagle Valleys adjacent to the Sierra Nevada. Radium-226 and 228Ra concentrations are processes. Thus, U is transported as dissolved and adsorbed species. A rise in the water table in the Carson Desert because of irrigation has resulted in the oxidation of U-rich organic matter and dissolution of U-bearing coatings on sediments, producing unusually high U concentration in the ground water. Alpha activity in the ground water is almost entirely from the decay of U dissolved in the water. Beta activity in ground water samples is primarily from the decay of 40K dissolved in the water and ingrowth of 238U progeny in the sample before analysis. Approximately one-half of the measured beta activity may not be present in ground water in the aquifer, but instead is produced in the sample after collection and before analysis. Potassium-40 is primarily from the dissolution of K-containing minerals, probably K-feldspar and biotite

Questa baseline and pre-mining ground-water quality investigation. 5. Well installation, water-level data, and surface- and ground-water geochemistry in the Straight Creek drainage basin, Red River Valley, New Mexico, 2001-03

Science.gov (United States)

Naus, Cheryl A.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Donohoe, Lisa C.; Hunt, Andrew G.; Paillet, Frederick L.; Morin, Roger H.; Verplanck, Philip L.

2005-01-01

The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and the Red River. Pyritized rock in the upper part of the drainage basin is the source of acid rock drainage (pH 2.8-3.3) that infiltrates debris-flow deposits containing acidic ground water (pH 3.0-4.0) and bedrock containing water of circumneutral pH values (5.6-7.7). Eleven observation wells were installed in the Straight Creek drainage basin. The wells were completed in debris-flow deposits, bedrock, and interfingering debris-flow and Red River alluvial deposits. Chemical analyses of ground water from these wells, combined with chemical analyses of surface water, water-level data, and lithologic and geophysical logs, provided information used to develop an understanding of the processes contributing to the chemistry of ground water in the Straight Creek drainage basin. Surface- and ground-water samples were routinely collected for determination of total major cations and selected trace metals; dissolved major cations, selected trace metals, and rare-earth elements; anions and alkalinity; and dissolved-iron species. Rare-earth elements were determined on selected samples only. Samples were collected for determination of dissolved organic carbon, mercury, sulfur isotopic composition (34S and 18O of sulfate), and water isotopic composition (2H and 18O) during

Characteristics and chemical composition of ground water in Bara basin

International Nuclear Information System (INIS)

Gibla, O.A.M.

2007-01-01

In this study analysis was carried for forty five ground water samples from different areas within Bara basin, fifteen solid samples, three locally produced salt samples and one mixed rocks sample. The rocks were brought from the underground during hand digging of wells. The study include areas Um-Galgie, Bara, Saatah Shambool, Um-Sadoun El-Shareef, EI-Dair, EI-Murra, Taybah, Um-sadoun EI-Nazir, EI-Hodied Shareef, Um-Nabeg, Um-Gazira, Magror, Ma'afa, El-Kheiran, Dameerat Abdu, Sharshar East, Sharshar West, El-Gaa'a Um-Safari, and El-Gaa'a Um EL-Gora. Physical characteristics of ground water samples were determined including pH, electrical conductivity, turbidity, and total dissolved solids, using pH-meter, conductivity-meter, and ultra- meter. Many other analytical techniques were used. Spectrophotometric analysis was used for determination of nitrate(NO 3 ''-''-), nitrite (No 2 ''-), ammonia-nitrogen (NH 3 -N), fluoride(F), sulphide(S''-''-) and sulphate(SO 4 ''-''-) ions. Chloride (Cl''-) and total alkalinity(OH''-,CO 3 ''-''-,HCO 3 ''-) were determined titrametrically. X-ray diffraction technique was used for determination of chemical composition of solid samples (soils,salts and rocks). X-ray fluorescence technique was used to measure the concentration of some metals in the solid samples. Radioactivity was measured using gamma-spectrometry. Atomic absorption spectrometry was used for the measurement of cations concentration in ground water samples as well as soil samples, this include macro-cations: sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) and micro cations (trace): Iron (Fe), manganese (Mn), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), silver (Ag), lead (Pb) and barium (Ba). The results obtained were statistically treated, using SPSS program, discussed and further future research was suggested. The analysis show general suitability of fresh ground water at section A and C samples from physical and chemical

Characteristics and chemical composition of ground water in Bara basin

Energy Technology Data Exchange (ETDEWEB)

Gibla, O A.M. [Sudan University of Science and Technology, College of Graduate Studies, Khartoum (Sudan)

2007-01-15

In this study analysis was carried for forty five ground water samples from different areas within Bara basin, fifteen solid samples, three locally produced salt samples and one mixed rocks sample. The rocks were brought from the underground during hand digging of wells. The study include areas Um-Galgie, Bara, Saatah Shambool, Um-Sadoun El-Shareef, EI-Dair, EI-Murra, Taybah, Um-sadoun EI-Nazir, EI-Hodied Shareef, Um-Nabeg, Um-Gazira, Magror, Ma'afa, El-Kheiran, Dameerat Abdu, Sharshar East, Sharshar West, El-Gaa'a Um-Safari, and El-Gaa'a Um EL-Gora. Physical characteristics of ground water samples were determined including pH, electrical conductivity, turbidity, and total dissolved solids, using pH-meter, conductivity-meter, and ultra- meter. Many other analytical techniques were used. Spectrophotometric analysis was used for determination of nitrate(NO{sub 3}''-''-), nitrite (No{sub 2}''-), ammonia-nitrogen (NH{sub 3}-N), fluoride(F), sulphide(S''-''-) and sulphate(SO{sub 4}''-''-) ions. Chloride (Cl''-) and total alkalinity(OH''-,CO{sub 3}''-''-,HCO{sub 3}''-) were determined titrametrically. X-ray diffraction technique was used for determination of chemical composition of solid samples (soils,salts and rocks). X-ray fluorescence technique was used to measure the concentration of some metals in the solid samples. Radioactivity was measured using gamma-spectrometry. Atomic absorption spectrometry was used for the measurement of cations concentration in ground water samples as well as soil samples, this include macro-cations: sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) and micro cations (trace): Iron (Fe), manganese (Mn), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), silver (Ag), lead (Pb) and barium (Ba). The results obtained were statistically treated, using SPSS program, discussed and further future research was suggested. The analysis show general suitability of fresh ground water at section A and C samples from

Effects of deep basins on structural collapse during large subduction earthquakes

Science.gov (United States)

Marafi, Nasser A.; Eberhard, Marc O.; Berman, Jeffrey W.; Wirth, Erin A.; Frankel, Arthur

2017-01-01

Deep sedimentary basins are known to increase the intensity of ground motions, but this effect is implicitly considered in seismic hazard maps used in U.S. building codes. The basin amplification of ground motions from subduction earthquakes is particularly important in the Pacific Northwest, where the hazard at long periods is dominated by such earthquakes. This paper evaluates the effects of basins on spectral accelerations, ground-motion duration, spectral shape, and structural collapse using subduction earthquake recordings from basins in Japan that have similar depths as the Puget Lowland basin. For three of the Japanese basins and the Puget Lowland basin, the spectral accelerations were amplified by a factor of 2 to 4 for periods above 2.0 s. The long-duration subduction earthquakes and the effects of basins on spectral shape combined, lower the spectral accelerations at collapse for a set of building archetypes relative to other ground motions. For the hypothetical case in which these motions represent the entire hazard, the archetypes would need to increase up to 3.3 times its strength to compensate for these effects.

Ground-based measurement of column-averaged mixing ratios of methane and carbon dioxide in the Sichuan Basin of China by a desktop optical spectrum analyzer

Science.gov (United States)

Qin, Xiu-Chun; Nakayama, Tomoki; Matsumi, Yutaka; Kawasaki, Masahiro; Ono, Akiko; Hayashida, Sachiko; Imasu, Ryoichi; Lei, Li-Ping; Murata, Isao; Kuroki, Takahiro; Ohashi, Masafumi

2018-01-01

Remote sensing of the atmospheric greenhouse gases, methane (CH4) and carbon dioxide (CO2), contributes to the understanding of global warming and climate change. A portable ground-based instrument consisting of a commercially available desktop optical spectrum analyzer and a small sun tracker has been applied to measure the column densities of atmospheric CH4 and CO2 at Yanting observation station in a mountainous paddy field of the Sichuan Basin from September to November 2013. The column-averaged dry-air molar mixing ratios, XCH4/XCO2, are compared with those retrieved by satellite observations in the Sichuan Basin and by ground-based network observations in the same latitude zone as the Yanting observation station.

Simulation of Regional Ground-Water Flow in the Suwannee River Basin, Northern Florida and Southern Georgia

Science.gov (United States)

Planert, Michael

2007-01-01

The Suwannee River Basin covers a total of nearly 9,950 square miles in north-central Florida and southern Georgia. In Florida, the Suwannee River Basin accounts for 4,250 square miles of north-central Florida. Evaluating the impacts of increased development in the Suwannee River Basin requires a quantitative understanding of the boundary conditions, hydrogeologic framework and hydraulic properties of the Floridan aquifer system, and the dynamics of water exchanges between the Suwannee River and its tributaries and the Floridan aquifer system. Major rivers within the Suwannee River Basin are the Suwannee, Santa Fe, Alapaha, and Withlacoochee. Four rivers west of the Suwannee River are the Aucilla, the Econfina, the Fenholloway, and the Steinhatchee; all drain to the Gulf of Mexico. Perhaps the most notable aspect of the surface-water hydrology of the study area is that large areas east of the Suwannee River are devoid of channelized, surface drainage; consequently, most of the drainage occurs through the subsurface. The ground-water flow system underlying the study area plays a critical role in the overall hydrology of this region of Florida because of the dominance of subsurface drain-age, and because ground-water flow sustains the flow of the rivers and springs. Three principal hydrogeologic units are present in the study area: the surficial aquifer system, the intermediate aquifer system, and the Floridan aquifer system. The surficial aquifer system principally consists of unconsoli-dated to poorly indurated siliciclastic deposits. The intermediate aquifer system, which contains the intermediate confining unit, lies below the surficial aquifer system (where present), and generally consists of fine-grained, uncon-solidated deposits of quartz sand, silt, and clay with interbedded limestone of Miocene age. Regionally, the intermediate aquifer system and intermediate con-fining unit act as a confining unit that restricts the exchange of water between the over

Observations of basin ground motions from a dense seismic array in San Jose, California

Science.gov (United States)

Frankel, A.; Carver, D.; Cranswick, E.; Bice, T.; Sell, R.; Hanson, S.

2001-01-01

We installed a dense array of 41 digital seismographs in San Jose, California, to evaluate in detail the effects of a deep sedimentary basin and shallow sedimentary deposits on earthquake ground motions. This urban array is located near the eastern edge of the Santa Clara Valley and spans the Evergreen sedimentary basin identified by gravity data. Average station spacing is 1 km, with three stations initially spaced 110 m apart. Despite the high-noise urban environment, the stations of the array successfully triggered on and recorded small local earthquakes (M 2.5-2.8 at 10-25 km distance) and larger regional events such as the M 5.0 Bolinas earthquake (90 km distance), M 4.6-5.6 earthquakes near Mammoth Lakes (270 km distance), M 4.9-5.6 events in western Nevada (420 km distance) and the M 7.1 Hector Mine earthquake (590 km distance). Maps of spectral ratios across the array show that the highest amplitudes in all frequency bands studied (0.125-8 Hz) are generally observed at stations farther from the eastern edge of the Santa Clara Valley. Larger spectral amplitudes are often observed above the western edge of the Evergreen Basin. Snapshots of the recorded wavefield crossing the array for regional events to the east reveal that large, low-frequency (0.125-0.5 Hz) arrivals after the S-wave travel from south to north across the array. A moving-window, cross-correlation analysis finds that these later arrivals are surface waves traveling from the south. The timing and propagation direction of these arrivals indicates that they were likely produced by scattering of incident S waves at the border of the Santa Clara Valley to the south of the array. It is remarkable that the largest low-frequency phases at many of the valley sites for regional events to the east are basin surface waves coming from a direction about 70 degrees different from that of the epicenters. Basin surface waves emanating from the eastern edge of the valley are also identified by the cross

Strong ground motion prediction using virtual earthquakes.

Science.gov (United States)

Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

2014-01-24

Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.

Status report: numerical modeling of ground-water flow in the Paleozoic formations, western Paradox Basin, Utah

International Nuclear Information System (INIS)

Dunbar, D.B.; Thackston, J.W.

1985-10-01

A three-dimensional finite-difference numerical model was applied to simulate the ground-water flow pattern in Paleozoic strata within the western Paradox Basin region. The primary purpose of the modeling was to test the present conceptual hydrogeologic model and evaluate data deficiencies. All available data on ground-water hydrology, although sparse in this area, were utilized as input to the model. Permeability and potentiometric levels were estimated from petroleum company drill-stem tests and water-supply wells; formation thicknesses were obtained from geologic correlation of borehole geophysical logs. Hydrogeologic judgment weighed heavily in the assignment of hydrologic values to geologic features for this preliminary modeling study. Calibration of the model was accomplished through trial-and-error matching of simulated potentiometric contours with available head data. Hypothetical flow patterns, flux rates, recharge amounts, and surface discharge amounts were produced by the model. 34 refs., 17 figs., 3 tabs

Hydrologic properties and ground-water flow systems of the Paleozoic rocks in the upper Colorado River basin in Arizona, Colorado, New Mexico, Utah, and Wyoming, excluding the San Juan Basin

Science.gov (United States)

Geldon, Arthur L.

2003-01-01

The hydrologic properties and ground-water flow systems of Paleozoic sedimentary rocks in the Upper Colorado River Basin were investigated under the Regional Aquifer-System Analysis (RASA) program of the U.S. Geological Survey in anticipation of the development of water supplies from bedrock aquifers to fulfill the region's growing water demands. The study area, in parts of Arizona, Colorado, New Mexico, Utah, and Wyoming, covers about 100,000 square miles. It includes parts of four physiographic provinces--the Middle Rocky Mountains, Wyoming Basin, Southern Rocky Mountains, and Colorado Plateaus. A variety of landforms, including mountains, plateaus, mesas, cuestas, plains, badlands, and canyons, are present. Altitudes range from 3,100 to 14,500 feet. Precipitation is distributed orographically and ranges from less than 6 inches per year at lower altitudes to more than 60 inches per year in some mountainous areas. Most of the infrequent precipitation at altitudes of less than 6,000 feet is consumed by evapotranspiration. The Colorado and Green Rivers are the principal streams: the 1964-82 average discharge of the Colorado River where it leaves the Upper Colorado River Basin is 12,170 cubic feet per second (a decrease of 5,680 cubic feet per second since construction of Glen Canyon Dam in 1963). On the basis of their predominant lithologic and hydrologic properties, the Paleozoic rocks are classified into four aquifers and three confining units. The Flathead aquifer, Gros Ventre confining unit, Bighorn aquifer, Elbert-Parting confining unit, and Madison aquifer (Redwall-Leadville and Darwin-Humbug zones) make up the Four Corners aquifer system. A thick sequence, composed mostly of Mississippian and Pennsylvanian shale, anhydrite, halite, and carbonate rocks--the Four Corners confining unit (Belden-Molas and Paradox-Eagle Valley subunits)--overlies the Four Corners aquifer system in most areas and inhibits vertical ground-water flow between the Four Corners aquifer

Hydrogeochemistry and simulated solute transport, Piceance Basin, northwestern Colorado

Science.gov (United States)

Robson, S.G.; Saulnier, G.J.

1981-01-01

Oil-shale mining activities in Piceance basin in northwestern Colorado could adversely affect the ground- and surface-water quality in the basin. This study of the hydrology and geochemistry of the area used ground-water solute-transport-modeling techniques to investigate the possible impact of the mines on water quality. Maps of the extent and structure of the aquifer were prepared and show that a saturated thickness of 2,000 feet occurs in the northeast part of the basin. Ground-water recharge in the upland areas in the east, south, and west parts of the basin moves down into deeper zones in the aquifer and laterally to the discharge areas along Piceance and Yellow Creeks. The saline zone and the unsaturated zone provide the majority of the dissolved solids found in the ground water. Precipitation, ion-exchange, and oxidation-reduction reactions are also occuring in the aquifer. Model simulations of ground-water pumpage in tracts C-a and C-b indicate that the altered direction of ground-water movement near the pumped mines will cause an improvement in ground-water quality near the mines and a degradation of water quality downgradient from the tracts. Model simulations of mine leaching in tract C-a and C-b indicate that equal rates of mine leaching in the tracts will produce much different effects on the water quality in the basin. Tract C-a, by virtue of its remote location from perennial streams, will primarily degrade the ground-water quality over a large area to the northeast of the tract. Tract C-b, by contrast, will primarily degrade the surface-water quality in Piceance Creek, with only localized effects on the ground-water quality. (USGS)

Biological significance of dead biomass retention trait in Mediterranean Basin species: an analysis between different successional niches and regeneration strategies as functional groups.

Science.gov (United States)

Baeza, M J; Santana, V M

2015-11-01

Standing dead biomass retention is considered one of the most relevant fuel structural traits to affect plant flammability. However, very little is known about the biological significance of this trait and its distribution between different functional groups. Our aim was to analyse how the proportion of dead biomass produced in Mediterranean species is related to the successional niche of species (early-, mid- and late-successional stages) and the regeneration strategy of species (seeders and resprouters). We evaluated biomass distribution by size classes and standing dead biomass retention in nine dominant species from the Mediterranean Basin in different development stages (5, 9, 14 and 26 years since the last fire). The results revealed significant differences in the standing dead biomass retention of species that presented a distinct successional niche or regeneration strategy. These differences were restricted to the oldest ages studied (>9 years). Tree and small tree resprouters, typical in late-successional stages, presented slight variations with age and a less marked trend to retain dead biomass, while seeder shrubs and dwarf shrubs, characteristic of early-successional stages, showed high dead biomass loads. Our results suggest that the species that tend to retain more dead branches are colonising species that may promote fire in early-successional stages. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

Water resources of the Cook Inlet Basin, Alaska

Science.gov (United States)

Freethey, Geoffrey W.; Scully, David R.

1980-01-01

Ground-water and surface-water systems of Cook Inlet basin, Alaska, are analyzed. Geologic and topographic features that control the movement and regional availability of ground water are explained and illustrated. Five aquifer systems beneath the most populous areas are described. Estimates of ground-water yield were determined for the region by using ground-water data for the populated areas and by extrapolating known subsurface conditions and interpreting subsurface conditions from surficial features in the other areas. Area maps of generalized geology, Quaternary sediment thickness, and general availability of ground water are shown. Surface-water resources are summarized by describing how basin characteristics affect the discharge in streams. Seasonal trend of streamflow for three types of streams is described. Regression equations for 4 streamflow characteristics (annual, monthly minimum, and maximum discharge) were obtained by using gaging station streamflow characteristics and 10 basin characteristics. In the 24 regression equations presented, drainage area is the most significant basin characteristic, but 5 others are used. Maps of mean annual unit runoff and minimum unit yield for 7 consecutive days with a recurrence interval of 10 years are shown. Historic discharge data at gaging stations is tabulated and representative low-flow and flood-flow frequency curves are shown. (USGS)

Airborne and ground-based transient electromagnetic mapping of groundwater salinity in the Machile–Zambezi Basin, southwestern Zambia

DEFF Research Database (Denmark)

Chongo, Mkhuzo; Vest Christiansen, Anders; Tembo, Alice

2015-01-01

The geological and morphological evolution of the Kalahari Basin of Southern Africa has given rise to a complex hydrogeological regime that is affected by water quality issues. Among these concerns is the occurrence of saline groundwater. Airborne and ground-based electromagnetic surveying...... of a low-resistivity (below 13 Ωm) valley that extends southwestwards into the Makgadikgadi salt pans. The electrical resistivity distribution is indicative of a full graben related to the Okavango–Linyati Fault system as a result of propagation of the East African Rift Valley System into Southern Africa...

Modelling of long term nitrogen retention in surface waters

Science.gov (United States)

Halbfaß, S.; Gebel, M.; Bürger, S.

2010-12-01

In order to derive measures to reduce nutrient loadings into waters in Saxony, we calculated nitrogen inputs with the model STOFFBILANZ on the regional scale. Thereby we have to compare our modelling results to measured loadings at the river basin outlets, considering long term nutrient retention in surface waters. The most important mechanism of nitrogen retention is the denitrification in the contact zone of water and sediment, being controlled by hydraulic and micro-biological processes. Retention capacity is derived on the basis of the nutrient spiralling concept, using water residence time (hydraulic aspect) and time-specific N-uptake by microorganisms (biological aspect). Short time related processes of mobilization and immobilization are neglected, because they are of minor importance for the derivation of measures on the regional scale.

Simulation of ground-water flow and evaluation of water-management alternatives in the upper Charles River basin, eastern Massachusetts

Science.gov (United States)

DeSimone, Leslie A.; Walter, Donald A.; Eggleston, John R.; Nimiroski, Mark T.

2002-01-01

Ground water is the primary source of drinking water for towns in the upper Charles River Basin, an area of 105 square miles in eastern Massachusetts that is undergoing rapid growth. The stratified-glacial aquifers in the basin are high yield, but also are thin, discontinuous, and in close hydraulic connection with streams, ponds, and wetlands. Water withdrawals averaged 10.1 million gallons per day in 1989?98 and are likely to increase in response to rapid growth. These withdrawals deplete streamflow and lower pond levels. A study was conducted to develop tools for evaluating water-management alternatives at the regional scale in the basin. Geologic and hydrologic data were compiled and collected to characterize the ground- and surface-water systems. Numerical flow modeling techniques were applied to evaluate the effects of increased withdrawals and altered recharge on ground-water levels, pond levels, and stream base flow. Simulation-optimization methods also were applied to test their efficacy for management of multiple water-supply and water-resource needs. Steady-state and transient ground-water-flow models were developed using the numerical modeling code MODFLOW-2000. The models were calibrated to 1989?98 average annual conditions of water withdrawals, water levels, and stream base flow. Model recharge rates were varied spatially, by land use, surficial geology, and septic-tank return flow. Recharge was changed during model calibration by means of parameter-estimation techniques to better match the estimated average annual base flow; area-weighted rates averaged 22.5 inches per year for the basin. Water withdrawals accounted for about 7 percent of total simulated flows through the stream-aquifer system and were about equal in magnitude to model-calculated rates of ground-water evapotranspiration from wetlands and ponds in aquifer areas. Water withdrawals as percentages of total flow varied spatially and temporally within an average year; maximum values were

Hydrogeology of the West Siberian Basin

International Nuclear Information System (INIS)

Foley, M.G.; Bradley, D.J.; Cole, C.R.

1996-01-01

Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in extensive radioactive contaminant releases to the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. We have assumed that ground-water flow in the West Siberian Basin is topographically driven, with recharge to the basin occurring in the highlands on the west, east, and south, and internal discharge localized in numerous river valleys and lakes that ultimately discharge north to the ocean. We are modeling the regional hydrogeology as three-dimensional, steady-state, saturated flow that is recharged from above. We acquired topographic, geologic, hydrostratigraphic, hydrogeologic, and water-balance data for the West Siberian Basin and constructed a regional water table. We correlated and combined 70 different rock types derived from published descriptions of West Siberian Basin rocks into 17 rock types appropriate for assignment of hydrogeologic properties on the basis of spatial heterogeneity and constituent (i.e., sand, silt, and clay) diversity. Examination of resulting three-dimensional assemblages of rock types showed that they were consistent with published and inferred paleogeography and depositional processes. Calibrating the basin's moisture balance (i.e., recharge and discharge) to the derived water table determined plausible input parameter values for unknowns such as hydraulic conductivities. The general directions of calculated ground-water flow suggest that major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks, and that ground-water divides that penetrate the entire thickness of the model are evident between major rivers

A conservationist approach on environmental diagnosis of ground use in the Iguatemi river basin, Mato Grosso do Sul State, Brazil - doi: 10.4025/actascibiolsci.v34i3.9001

Directory of Open Access Journals (Sweden)

Marco Antonio Gomes Souto

2012-06-01

Full Text Available Landscape Ecology is a contemporary approach in conservation studies in which, coupled to the development and use of GIS-based tools, provides new methods for the analysis of forest fragments. Based on these new approaches, the environmental assessment of ground use in the Iguatemi river basin Mato Grosso do Sul State, Brazil is provided through conservation-based flora and ecology aspects. A regional map of ground use with field-collected data using Rapid Ecological Assessment methodology and digital satellite images was prepared. AER analysis showed a highly impacted region featuring intense transformation in ground use with a conversion of 87% of native forest into grazing and agriculture land. The general situation is inconsistent with APA guidelines, the conservationist unit which operates in the river basin. PPAs’ recovery, erosion control and adjustment to current environmental regulations are mandatory.  

Ground-Water Flow Model of the Sierra Vista Subwatershed and Sonoran Portions of the Upper San Pedro Basin, Southeastern Arizona, United States, and Northern Sonora, Mexico

Science.gov (United States)

Pool, D.R.; Dickinson, Jesse

2007-01-01

A numerical ground-water model was developed to simulate seasonal and long-term variations in ground-water flow in the Sierra Vista subwatershed, Arizona, United States, and Sonora, Mexico, portions of the Upper San Pedro Basin. This model includes the simulation of details of the groundwater flow system that were not simulated by previous models, such as ground-water flow in the sedimentary rocks that surround and underlie the alluvial basin deposits, withdrawals for dewatering purposes at the Tombstone mine, discharge to springs in the Huachuca Mountains, thick low-permeability intervals of silt and clay that separate the ground-water flow system into deep-confined and shallow-unconfined systems, ephemeral-channel recharge, and seasonal variations in ground-water discharge by wells and evapotranspiration. Steady-state and transient conditions during 1902-2003 were simulated by using a five-layer numerical ground- water flow model representing multiple hydrogeologic units. Hydraulic properties of model layers, streamflow, and evapotranspiration rates were estimated as part of the calibration process by using observed water levels, vertical hydraulic gradients, streamflow, and estimated evapotranspiration rates as constraints. Simulations approximate observed water-level trends throughout most of the model area and streamflow trends at the Charleston streamflow-gaging station on the San Pedro River. Differences in observed and simulated water levels, streamflow, and evapotranspiration could be reduced through simulation of climate-related variations in recharge rates and recharge from flood-flow infiltration.

Description and comparison of selected models for hydrologic analysis of ground-water flow, St Joseph River basin, Indiana

Science.gov (United States)

Peters, J.G.

1987-01-01

The Indiana Department of Natural Resources (IDNR) is developing water-management policies designed to assess the effects of irrigation and other water uses on water supply in the basin. In support of this effort, the USGS, in cooperation with IDNR, began a study to evaluate appropriate methods for analyzing the effects of pumping on ground-water levels and streamflow in the basin 's glacial aquifer systems. Four analytical models describe drawdown for a nonleaky, confined aquifer and fully penetrating well; a leaky, confined aquifer and fully penetrating well; a leaky, confined aquifer and partially penetrating well; and an unconfined aquifer and partially penetrating well. Analytical equations, simplifying assumptions, and methods of application are described for each model. In addition to these four models, several other analytical models were used to predict the effects of ground-water pumping on water levels in the aquifer and on streamflow in local areas with up to two pumping wells. Analytical models for a variety of other hydrogeologic conditions are cited. A digital ground-water flow model was used to describe how a numerical model can be applied to a glacial aquifer system. The numerical model was used to predict the effects of six pumping plans in 46.5 sq mi area with as many as 150 wells. Water budgets for the six pumping plans were used to estimate the effect of pumping on streamflow reduction. Results of the analytical and numerical models indicate that, in general, the glacial aquifers in the basin are highly permeable. Radial hydraulic conductivity calculated by the analytical models ranged from 280 to 600 ft/day, compared to 210 and 360 ft/day used in the numerical model. Maximum seasonal pumping for irrigation produced maximum calculated drawdown of only one-fourth of available drawdown and reduced streamflow by as much as 21%. Analytical models are useful in estimating aquifer properties and predicting local effects of pumping in areas with

A hybrid method for the estimation of ground motion in sedimentary basins: Quantitative modelling for Mexico City

International Nuclear Information System (INIS)

Faeh, D.; Suhadolc, P.; Mueller, S.; Panza, G.F.

1994-04-01

To estimate the ground motion in two-dimensional, laterally heterogeneous, anelastic media, a hybrid technique has been developed which combines modal summation and the finite difference method. In the calculation of the local wavefield due to a seismic event, both for small and large epicentral distances, it is possible to take into account the sources, path and local soil effects. As practical application we have simulated the ground motion in Mexico City caused by the Michoacan earthquake of September 19, 1985. By studying the one-dimensional response of the two sedimentary layers present in Mexico City, it is possible to explain the difference in amplitudes observed between records for receivers inside and outside the lake-bed zone. These simple models show that the sedimentary cover produces the concentration of high-frequency waves (0.2-0.5 Hz) on the horizontal components of motion. The large amplitude coda of ground motion observed inside the lake-bed zone, and the spectral ratios between signals observed inside and outside the lake-bed zone, can only be explained by two-dimensional models of the sedimentary basin. In such models, the ground motion is mainly controlled by the response of the uppermost clay layer. The synthetic signals explain the major characteristics (relative amplitudes, spectral ratios, and frequency content) of the observed ground motion. The large amplitude coda of the ground motion observed in the lake-bed zone can be explained as resonance effects and the excitation of local surface waves in the laterally heterogeneous clay layer. Also, for the 1985 Michoacan event, the energy contributions of the three subevents are important to explain the observed durations. (author). 39 refs, 15 figs, 1 tab

Quality of water in an inactive uranium mine and its effects on the quality of water in Blue Creek, Stevens County, Washington, 1984-85. Water Resources Investigation

International Nuclear Information System (INIS)

Sumioka, S.S.

1991-01-01

The purpose of the report is to present the results of a study done to determine (1) the monthly and annual water budgets and probable variation in runoff for the drainage basin in which the mine is located; (2) if precipitation is the source of low pH water found in pit 3 and the retention pond; (3) the quality of water in pits 3 and 4, the retention pond, streamflow from the basin, Blue Creek upstream and downstream of the point the drainage enters, and near the mouth of Blue Creek; (4) the quality of ground water discharged from the basin into Blue Creek; and (5) the daily mean values of discharge, water temperature, specific conductance, and pH for mine drainage from the basin, Blue Creek upstream and downstream of the mine drainage, and near the mouth of Blue Creek. The report also describes a potential water-quality monitoring program that would allow the determination of annual loads of selected chemical constituents entering Blue Creek from the mine basin and information about the type of ground-water tracers and procedures needed to examine flow paths near the retention pond

The importance of hunting and hunting grounds for big and small game for tourism development in the basin of Crna Reka the Republic of Macedonia

OpenAIRE

Koteski, Cane; Jakovlev, Zlatko; Mitreva, Elizabeta; Angelkova, Tanja; Kitanov, Vladimir

2012-01-01

To show the hunting and hunting grounds for big and small game, the structure of the areas of certain hunting, fishing, fishing water objects, fish species, fishponds up to 20 years shown by municipalities and individual farms with ponds in the basin of Crna Reka.

Resonance properties of tidal channels with multiple retention basins: role of adjacent sea

Science.gov (United States)

Roos, Pieter C.; Schuttelaars, Henk M.

2015-03-01

We present an idealised model of the tidal response in a main channel with multiple secondary basins, co-oscillating with an adjacent sea. The sea is represented as a semi-infinite strip of finite width, anywhere between the limits of a channel extension (narrow) and a half-plane (wide). The sea geometry controls the extent to which radiative damping takes place and hence the type of conditions that effectively apply at the channel mouth. These conditions range between the two extremes of prescribing elevation (deep sea limit) and prescribing the incoming wave (sea as channel extension of the same depth, as done in an earlier study). The closer to this first extreme, the stronger the oscillations in the secondary basins may feed back onto the channel mouth and thus produce an amplified or weakened response in the system as a whole. The possibly resonant response is explained by analysing the additional waves that emerge on either side of the entrance of the secondary basin. Finally, we show that the simultaneous presence of two secondary basins may amplify or weaken the accumulated responses to these basins individually.

A comparison of ground-based and aircraft-based methane emission flux estimates in a western oil and natural gas production basin

Science.gov (United States)

Snare, Dustin A.

Recent increases in oil and gas production from unconventional reservoirs has brought with it an increase of methane emissions. Estimating methane emissions from oil and gas production is complex due to differences in equipment designs, maintenance, and variable product composition. Site access to oil and gas production equipment can be difficult and time consuming, making remote assessment of emissions vital to understanding local point source emissions. This work presents measurements of methane leakage made from a new ground-based mobile laboratory and a research aircraft around oil and gas fields in the Upper Green River Basin (UGRB) of Wyoming in 2014. It was recently shown that the application of the Point Source Gaussian (PSG) method, utilizing atmospheric dispersion tables developed by US EPA (Appendix B), is an effective way to accurately measure methane flux from a ground-based location downwind of a source without the use of a tracer (Brantley et al., 2014). Aircraft measurements of methane enhancement regions downwind of oil and natural gas production and Planetary Boundary Layer observations are utilized to obtain a flux for the entire UGRB. Methane emissions are compared to volumes of natural gas produced to derive a leakage rate from production operations for individual production sites and basin-wide production. Ground-based flux estimates derive a leakage rate of 0.14 - 0.78 % (95 % confidence interval) per site with a mass-weighted average (MWA) of 0.20 % for all sites. Aircraft-based flux estimates derive a MWA leakage rate of 0.54 - 0.91 % for the UGRB.

Organic geochemistry of deep ground waters from the Palo Duro Basin, Texas: implications for radionuclide complexation, ground-water origin, and petroleum exploration

International Nuclear Information System (INIS)

Means, J.L.; Hubbard, N.J.

1985-05-01

This report describes the organic geochemistry of 11 ground-water samples from the Palo Duro Basin, Texas and discusses the implications of their organic geochemical compositions in terms of radionuclide complexation, ground-water origin, and the petroleum potential of two candidate repository sites in Deaf Smith and Swisher Counties. Short-chain aliphatic acid anions are the principal organic constituents present. Stability constant data and simple chemical equilibria calculations suggest that short-chain aliphatic acids are relatively weak complexing agents. The extent of complexation of a typical actinide by selected inorganic ligands present in these brines is expected to far outweigh actinide complexation by the aliphatic acid anions. Various lines of evidence suggest that some portion of the bromide concentrations in the brines is derived from the same source as the short-chain aliphatic acid anions. When the postulated organic components are subtracted from total bromide concentrations, the origins of the Palo Duro brines, based on chloride versus bromide relationships, appear largely consistent with origins based on isotopic evidence. The short-chain aliphatic acid anion content of the Palo Duro brines is postulated to have been much greater in the geologic past. Aliphatic acid anions are but one of numerous petroleum proximity indicators, which consistently suggest a greater petroleum exploration potential for the area surrounding the Swisher County site than the region encompassing the candidate site in Deaf Smith County. Short-chain aliphatic acid anions appear to provide a useful petroleum exploration tool as long as the complex reactions that may dimish their concentrations in ground water are recognized. 71 refs., 10 figs., 10 tabs

Recruitment and Retention with a Spin

Science.gov (United States)

Lindgren, Rita; Hixson, Carla Braun

2010-01-01

Strategic planning and innovation at Bismarck State College (BSC) found common ground in the college's goal to recruit and retain employees in an environment of low unemployment and strong competition for skilled employees. BSC's strategic plan for 2007-09 included the objective "to increase retention of employees." One of the strategies…

Chemistry of ground water in the Silver Springs basin, Florida, with an emphasis on nitrate

Science.gov (United States)

Phelps, G.G.

2004-01-01

The Silver Springs group, in central Marion County, Florida, has a combined average discharge rate of 796 cubic feet per second and forms the headwaters of the Silver River. The springs support a diverse ecosystem and are an important cultural and economic resource. Concentrations of nitrite-plus-nitrate (nitrate-N) in water from the Main Spring increased from less than 0.5 milligrams per liter (mg/L) in the 1960s to about 1.0 mg/L in 2003. The Upper Floridan aquifer supplies the ground water to support spring discharge. This aquifer is at or near land surface in much of the ground-water basin; nutrients leached at land surface can easily percolate downward into the aquifer. Sources of nitrogen in ground water in the Silver Springs basin include atmospheric deposition, fertilizers used by agricultural and urban activities, and human and animal wastes. During 2000-2001, 56 wells in the area contributing recharge to Silver Springs were sampled for major ions, nutrients, and some trace constituents. Selected wells also were sampled for a suite of organic constituents commonly found in domestic and industrial wastewater and for the ratio of nitrogen isotopes (15N/14N) to better understand the sources of nitrate. Wells were selected to be representative of both confined and unconfined conditions of the Upper Floridan aquifer, as well as a variety of land-use types. Data from this study were compared to data collected from 25 wells in 1989-90. Concentrations of nitrate-N in ground water during this study ranged from less than the detection limit of 0.02 to 12 mg/L, with a median of 1.2 mg/L. For data from 1989-90, the range was from less than 0.02 to 3.6 mg/L, with a median of 1.04 mg/L. Water from wells in agricultural land-use areas had the highest median nitrate-N concentration (1.7 mg/L), although it is uncertain if the 12 mg/L maximum concentration was influenced by land-use activities or proximity to a septic tank. The median value for all urban land-use areas was

Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

International Nuclear Information System (INIS)

Engqvist, A.

1997-08-01

A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed

RAINWATER RETENTION ON THE HEAVILY INDUSTRIALIZED AREAS

Directory of Open Access Journals (Sweden)

Bartosz Kaźmierczak

2016-06-01

Full Text Available The paper presents the dimensioning of retention reservoirs indicator method regarding to the German DWA-A 117 guideline, recommended for small rainfall catchments (with an area of 200 ha. A comparative calculation of the retention reservoirs overflow useful volume were conducted for 4 variants of catchment development (degree sealing surface varied from 60% to 90%, under the assumed sewage outflow from the tank at the level of the urban basin natural runoff. At given conditions required unit volume of retention reservoirs, from 145.4 m3 to 206.7 m3 for each 1 ha of catchment area were determined. The obtained results confirmed the fact that useful volume of the tanks were decreased, when Blaszczyk’s pattern reliable rainwater streams were used for calculations. Because the DWA-A 117 guideline method should be applied to a small rainfall catchments, it is recommended to verify the hydraulic capacity of dimensioned channels and objects using hydrodynamic simulations at different load of rainfall catchment scenarios, variable in time and space.

Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

Science.gov (United States)

Lee, Terrie Mackin

2002-01-01

In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large

Modeling Nonlinear Site Response Uncertainty in Broadband Ground Motion Simulations for the Los Angeles Basin

Science.gov (United States)

Assimaki, D.; Li, W.; Steidl, J. M.; Schmedes, J.

2007-12-01

The assessment of strong motion site response is of great significance, both for mitigating seismic hazard and for performing detailed analyses of earthquake source characteristics. There currently exists, however, large degree of uncertainty concerning the mathematical model to be employed for the computationally efficient evaluation of local site effects, and the site investigation program necessary to evaluate the nonlinear input model parameters and ensure cost-effective predictions; and while site response observations may provide critical constraints on interpretation methods, the lack of a statistically significant number of in-situ strong motion records prohibits statistical analyses to be conducted and uncertainties to be quantified based entirely on field data. In this paper, we combine downhole observations and broadband ground motion synthetics for characteristic site conditions the Los Angeles Basin, and investigate the variability in ground motion estimation introduced by the site response assessment methodology. In particular, site-specific regional velocity and attenuation structures are initially compiled using near-surface geotechnical data collected at downhole geotechnical arrays, inverse low-strain velocity and attenuation profiles at these sites obtained by inversion of weak motion records and the crustal velocity structure at the corresponding locations obtained from the Southern California Earthquake Centre Community Velocity Model. Successively, broadband ground motions are simulated by means of a hybrid low/high-frequency finite source model with correlated random parameters for rupture scenaria of weak, medium and large magnitude events (M =3.5-7.5). Observed estimates of site response at the stations of interest are first compared to the ensemble of approximate and incremental nonlinear site response models. Parametric studies are next conducted for each fixed magnitude (fault geometry) scenario by varying the source-to-site distance and

Heat flow and subsurface temperature as evidence for basin-scale ground-water flow, North Slope of Alaska

Science.gov (United States)

Deming, D.; Sass, J.H.; Lachenbruch, A.H.; De Rito, R. F.

1992-01-01

Several high-resolution temperature logs were made in each of 21 drillholes and a total of 601 thermal conductivity measurements were made on drill cuttings and cores. Near-surface heat flow (??20%) is inversely correlated with elevation and ranges from a low of 27 mW/m2 in the foothills of the Brooks Range in the south, to a high of 90 mW/m2 near the north coast. Subsurface temperatures and thermal gradients estimated from corrected BHTs are similarly much higher on the coastal plain than in the foothills province to the south. Significant east-west variation in heat flow and subsurface temperature is also observed; higher heat flow and temperature coincide with higher basement topography. The observed thermal pattern is consistent with forced convection by a topographically driven ground-water flow system. Average ground-water (Darcy) velocity in the postulated flow system is estimated to be of the order of 0.1 m/yr; the effective basin-scale permeability is estimated to be of the order of 10-14 m2. -from Authors

Report of the panel on evaluation of ground-water flow in fractures at the Palo Duro Basin, Texas: Unanalyzed data: Technical report

International Nuclear Information System (INIS)

1988-01-01

A peer review group of hydrologists assessed the importance and availability of data on fracture-controlled ground-water flow at the Palo Duro Basin sites in the Permian Basin in Texas. After hearing presentations by US Department of Energy staff and consultants, and reviewing existing literature, they formed a conceptual model of basin flow that is downward across the salt facies and downdip in permeable formation in the lower hydrostratigraphic unit. Flow volumes and rates are very low. The panel examined several possible fracture-flow scenarios and concluded that flow within the salt section is probably porous-media-dominated with some fracture-flow influence in brittle zones. Fracture flow in the salt itself is rejected as a possibility based on current evidence. However, the panel recommended that fracture flow in the system should be included as a low-probability variable in any hydrogeologic modeling. They also concluded that many more data on lineament features and subsurface structures are needed to accurately characterize the system and to refine the modeling effort. 9 refs., 2 figs

Understanding the Influence of Retention Basin on Tidal Dynamics in Tidal Estuaries

Science.gov (United States)

Kumar, Mohit; Schuttelaars, Henk; Roos, Pieter

2014-05-01

Both the tidal motion and suspended sediment concentration (SSC) in tidal embayments and estuaries are influenced by anthropogenic (e.g. deepening ) and natural changes. An example of such an estuary is the Ems estuary, situated on the border of the Netherlands and Germany. The mean tidal range towards the end of the Ems estuary has increased from 1.5m in the 1950s to more than 3m in the 1990s while the suspended concentration has increased by a factor 10. To possibly reduce these negative effects, the construction of retention basin(s) (RB) is considered. In this contribution, the influence of location and geometry of RBs on tidal dynamics and SSC is investigated. For this purpose, a three-dimensional semi-analytic idealized model is developed. This model is an extension of the model proposed by Winant (2007) to arbitrary domain and realistic bathymetry with partial slip boundary condition at the bottom. The sea surface elevation (SSE) is calculated numerically using a finite element method. Next, the three-dimensional velocities are calculated by combining the analytically calculated vertical profiles and the gradients of the SSE which are obtained numerically. Firstly, the influence of a RB on the tidal dynamics in an infinitely long, rectangular, frictionless estuary is considered. The SSE decreases when the RB is located between a node and a landward antinode, consistent with the work of Alebregtse et al. (2013). Secondly, an estuary of finite length is connected to a sea. By varying the width of the sea, not only the effect of the distance of the RB to the landward end plays a role, but also the distance to the open sea becomes important. Finally, we discuss the influence of a RB on the tidal motion and initial sediment transport, considering the Ems estuary with realistic bathymetry. Results show that the SSE at the landward end of the Ems estuary decreases for all locations of the RBs. This decrease is most pronounced for the RB which is closest to the end

Effects of streambank fencing of pasture land on benthic macroinvertebrates and the quality of surface water and shallow ground water in the Big Spring Run basin of Mill Creek watershed, Lancaster County, Pennsylvania, 1993-2001

Science.gov (United States)

Galeone, Daniel G.; Brightbill, Robin A.; Low, Dennis J.; O'Brien, David L.

2006-01-01

Streambank fencing along stream channels in pastured areas and the exclusion of pasture animals from the channel are best-management practices designed to reduce nutrient and suspended-sediment yields from drainage basins. Establishment of vegetation in the fenced area helps to stabilize streambanks and provides better habitat for wildlife in and near the stream. This study documented the effectiveness of a 5- to 12-foot-wide buffer strip on the quality of surface water and near-stream ground water in a 1.42-mi2 treatment basin in Lancaster County, Pa. Two miles of stream were fenced in the basin in 1997 following a 3- to 4-year pre-treatment period of monitoring surface- and ground-water variables in the treatment and control basins. Changes in surface- and ground-water quality were monitored for about 4 years after fence installation. To alleviate problems in result interpretation associated with climatic and hydrologic variation over the study period, a nested experimental design including paired-basin and upstream/downstream components was used to study the effects of fencing on surface-water quality and benthic-macroinvertebrate communities. Five surface-water sites, one at the outlet of a 1.77-mi2 control basin (C-1), two sites in the treatment basin (T-3 and T-4) that were above any fence installation, and two sites (one at an upstream tributary site (T-2) and one at the outlet (T-1)) that were treated, were sampled intensively. Low-flow samples were collected at each site (approximately 25-30 per year at each site), and stormflow was sampled with automatic samplers at all sites except T-3. For each site where stormflow was sampled, from 35 to 60 percent of the storm events were sampled over the entire study period. Surface-water sites were sampled for analyses of nutrients, suspended sediment, and fecal streptococcus (only low-flow samples), with field parameters (only low-flow samples) measured during sample collection. Benthic-macroinvertebrate samples

Potential for ground-water contamination from movement of wastewater through the unsaturated zone, upper Mojave River Basin, California

Science.gov (United States)

Umari, A.M.; Martin, P.M.; Schroeder, R.A.; Duell, L.F.; Fay, R.G.

1993-01-01

Septic-tank wastewater disposed in 30-foot-deep seepage pits (dry wells) at 46,000 residences is estimated to equal 18 percent of the natural recharge to the sole-source aquifer in the rapidly developing upper Mojave River Basin (Victor Valley) in the high desert northeast of Los Angeles. Vertical rates of movement of the wastewater wetting front through the unsaturated zone at three newly occupied residences ranged from 0.07 to 1.0 foot per day. These rates translate to traveltimes of several months to several years for the wastewater wetting front to reach the water table and imply that wastewater from many disposal systems already has reached the water table, which averages about 150 feet below land surface in the Victor Valley. As wastewater percolates from seepage pits into the adjacent unsaturated zone, the nitrogen present in reduced form is rapidly converted to nitrate. Analyses on soil-core extracts and soil moisturefrom suction lysimeters installed beneath the seepage pits at eight residences showed that nitrate concentrations and nitrate/ chloride ratios generally become lower with increasing depth. The intervals of greatest decline seemed to coincide with finer soil texture or were near the water table. Nitrate-reducing bacteria were tested for and found to be present in soil cores from two residences. Sparse nitrogen-15 data from suction lysimeters at one of these residences, where thenitrate concentration decreased by about one-half at a depth of 200 feet, indicate that the nitrate decline was accompanied by nitrogen-15 enrichment in the residual nitrate with an isotope-separation factor of about -10 permil. Despite the potential input of abundant nitrogen with the domestic wastewater recharge, nitrate concentrations in the area's ground water are generally low. The absence of high nitrate concentrations in the ground water is consistent with the existence of denitrification, a microbial nitrogen-removal mechanism, as wastewater moves through the

HVDC Ground Electrodes and Tectonic Setting

Science.gov (United States)

Freire, P. F.; Pereira, S. Y.

2017-12-01

Ground electrodes in HVDC transmission are huge grounding systems for the DC part of the converter substation, about 1 km wide, sized to inject in the ground DC currents up to 3.5 kA. This work presents an analysis of how the tectonic setting at converter substation location is determinant for the search of the best electrode location (Site Selection) and on its design and performance. It will briefly present the author experience on HVDC electrode design, summarized as follows: Itaipu - Foz do Iguaçu electrodes (transmitter side) located in the middle of Paraná Sedimentary Basin, and Ibiúna electrodes (receiving side) on the border of the basin, 6 km from the geological strike, where the crystalline basement outcrops in São Paulo state; Madeira River - North electrodes (transmitting side) located on the Northwest border of South Amazon Craton, where the crystalline basement is below a shallow sediments layer, and South electrodes (receiving side) located within Paraná Sedimentary Basin; Chile - electrodes located on the Andean forearc, where the Nazca Plate plunges under the South American Plate; Kenya - Ethiopia - electrodes located in the African Rift; Belo Monte - North electrodes (transmitter side) located within the Amazonian Sedimentary Basin, about 35 km of its South border, and South electrodes (receiving side) within Paraná Sedimentary Basin (bipole 1) and on crystalline metamorphic terrain "Brasília Belt" (bipole 2). This diversity of geological conditions results on ground electrodes of different topologies and dimensions, with quite different electrical and thermal performances. A brief study of the geology of the converter stations regions, the so-called Desktop Study, allows for the preview of several important parameters for the site selection and design of the electrodes, such as localization, type, size and estimate of the interference area, which are important predictors of the investment to be made and indications of the design to be

Geographic information system datasets of regolith-thickness data, regolith-thickness contours, raster-based regolith thickness, and aquifer-test and specific-capacity data for the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado

Science.gov (United States)

Arnold, L. Rick

2010-01-01

These datasets were compiled in support of U.S. Geological Survey Scientific-Investigations Report 2010-5082-Hydrogeology and Steady-State Numerical Simulation of Groundwater Flow in the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado. The datasets were developed by the U.S. Geological Survey in cooperation with the Lost Creek Ground Water Management District and the Colorado Geological Survey. The four datasets are described as follows and methods used to develop the datasets are further described in Scientific-Investigations Report 2010-5082: (1) ds507_regolith_data: This point dataset contains geologic information concerning regolith (unconsolidated sediment) thickness and top-of-bedrock altitude at selected well and test-hole locations in and near the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado. Data were compiled from published reports, consultant reports, and from lithologic logs of wells and test holes on file with the U.S. Geological Survey Colorado Water Science Center and the Colorado Division of Water Resources. (2) ds507_regthick_contours: This dataset consists of contours showing generalized lines of equal regolith thickness overlying bedrock in the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado. Regolith thickness was contoured manually on the basis of information provided in the dataset ds507_regolith_data. (3) ds507_regthick_grid: This dataset consists of raster-based generalized thickness of regolith overlying bedrock in the Lost Creek Designated Ground Water Basin, Weld, Adams, and Arapahoe Counties, Colorado. Regolith thickness in this dataset was derived from contours presented in the dataset ds507_regthick_contours. (4) ds507_welltest_data: This point dataset contains estimates of aquifer transmissivity and hydraulic conductivity at selected well locations in the Lost Creek Designated Ground Water Basin, Weld, Adams, and

Assessment of retention parameters of the fission products in the soil

International Nuclear Information System (INIS)

Endo, Laura Sakiko

1978-01-01

In many countries the discharge of radioactive liquid wastes into the ground is a common practice. The retention capacity presented by soils allows the discharge of bulky amounts of wastes in low and intermediate concentrations, within safety conditions. In addition, operations of ground disposal have advantages in economy and simplicity. However, the possibility of contamination of water resources is important in the site selection for such purpose. In this work, the I.E.A. soil behavior related to the retention capacity of cesium and strontium was studied. Distribution coefficients (Kd) were determined for both elements in function of its concentrations, p H and the presence of K + and Na + in the waste solutions. Soil analysis by X-ray diffraction showed the predominance Kaolinite argyle in this region. Soil parameters were also determined in laboratory conditions, such as permeability, porosity and density. The observed retention capacity for both elements was between 0,7 and 2,0 meg/100 of soil. Evaluation of ground water velocity and ions migration rates were carried out through the results obtained in laboratory measurements. It was also evaluated the amounts of 137 Cs and 90 Sr that if discharged into the ground would produce in the critical group a dose equal to the dose limit fixed by the norms. It was concluded that the maximum discharge amounts is limited by heat dissipation capacity of ground water table, and through a very conservative evaluation the total beta-gamma activity for long-lives radioisotopes presented a value of 3,6 X 10 6 Ci/y. (author)

Evaluation of nutrient retention in vegetated filter strips using the SWAT model.

Science.gov (United States)

Elçi, Alper

2017-11-01

Nutrient fluxes in stream basins need to be controlled to achieve good water quality status. In stream basins with intensive agricultural activities, nutrients predominantly come from diffuse sources. Therefore, best management practices (BMPs) are increasingly implemented to reduce nutrient input to streams. The objective of this study is to evaluate the impact of vegetated filter strip (VFS) application as an agricultural BMP. For this purpose, SWAT is chosen, a semi-distributed water quality assessment model that works at the watershed scale, and applied on the Nif stream basin, a small-sized basin in Western Turkey. The model is calibrated with an automated procedure against measured monthly discharge data. Nutrient loads for each sub-basin are estimated considering basin-wide data on chemical fertilizer and manure usage, population data for septic tank effluents and information about the land cover. Nutrient loads for 19 sub-basins are predicted on an annual basis. Average total nitrogen and total phosphorus loads are estimated as 47.85 t/yr and 13.36 t/yr for the entire basin. Results show that VFS application in one sub-basin offers limited retention of nutrients and that a selection of 20-m filter width is most effective from a cost-benefit perspective.

Nutrient transport and transformation beneath an infiltration basin

Science.gov (United States)

Sumner, D.M.; Rolston, D.E.; Bradner, L.A.

1998-01-01

Field experiments were conducted to examine nutrient transport and transformation beneath an infiltration basin used for the disposal of treated wastewater. Removal of nitrogen from infiltrating water by denitrification was negligible beneath the basin, probably because of subsurface aeration as a result of daily interruptions in basin loading. Retention of organic nitrogen in the upper 4.6 m of the unsaturated zone (water table depth of approximately 11 m) during basin loading resulted in concentrations of nitrate as much as 10 times that of the applied treated wastewater, following basin 'rest' periods of several weeks, which allowed time for mineralization and nitrification. Approximately 90% of the phosphorus in treated wastewater was removed within the upper 4.6 m of the subsurface, primarily by adsorption reactions, with abundant iron and aluminum oxyhydroxides occurring as soil coatings. A reduction in the flow rate of infiltrating water arriving at the water table may explain the accumulation of relatively coarse (>0.45 ??m), organic forms of nitrogen and phosphorus slightly below the water table. Mineralization and nitrification reactions at this second location of organic nitrogen accumulation contributed to concentrations of nitrate as much as three times that of the applied treated wastewater. Phosphorus, which accumulated below the water table, was immobilized by adsorption or precipitation reactions during basin rest periods.Field experiments were conducted to examine nutrient transport and transformation beneath an infiltration basin used for the disposal of treated wastewater. Removal of nitrogen from infiltrating water by denitrification was negligible beneath the basin, probably because of subsurface aeration as a result of daily interruptions in basin loading. Retention of organic nitrogen in the upper 4.6 m of the unsaturated zone (water table depth of approximately 11 m) during basin loading resulted in concentrations of nitrate as much as 10

Structure and diversity of ground mesofauna inUlmus and Populus consortia in the industrial areas of mining and smelting complex of krivyi rig basin

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V. V. Kachinskaya

2010-05-01

Full Text Available The structure and biological diversity of ground mesofauna on a consortium level of organisation of ecosystems are considered. Indicators of structural organisation and biodiversity of ground mesofauna were analised in Ulmus and Populus consortia in the conditions of industrial territories of mining and smelting complex of Krivyi Rig Basin. It is established that taxonomical structure of ground mesofauna is characterised by insignificant number and quantity of taxonomical groups. Prevalence of hortobionts and herpetobionts in morpho-ecological structure of the community testifies to their attachment to consortium’s determinants and influence of steppe climate on its structure. Dominance of phytophages and polyphages in trophic structure is caused by a combination of consortium determinants specificity and «a zone source» of the fauna formations. The structural organisation of ground mesofauna in consortia of Ulmus and Populus in the conditions of industrial sites is characterised by simplified taxonomical structure with low biodiversity at all levels.

Characterising flow regime and interrelation between surface-water and ground-water in the Fuente de Piedra salt lake basin by means of stable isotopes, hydrogeochemical and hydraulic data

Science.gov (United States)

Kohfahl, Claus; Rodriguez, Miguel; Fenk, Cord; Menz, Christian; Benavente, Jose; Hubberten, Hans; Meyer, Hanno; Paul, Liisa; Knappe, Andrea; López-Geta, Juan Antonio; Pekdeger, Asaf

2008-03-01

SummaryThis research reports the characterisation of ground- and surface-water interaction in the Fuente de Piedra Salt lake basin in southern Spain by a combined approach using hydraulic, hydrogeochemical and stable isotope data. During three sampling campaigns (February 2004, 2005 and October 2005) ground- and surface-water samples were collected for stable isotope studies ( 18O, D) and for major and minor ion analysis. Hydraulic measurements at multilevel piezometers were carried out at four different locations around the lake edge. Conductivity logs were performed at four piezometers located along a profile at the northern lake border and at two deeper piezometers in the Miocene basin at a greater distance from the lake. To describe processes that control the brine evolution different hydrogeochemical simulations were performed. Hydrogeochemical data show a variety of brines related to thickness variations of lacustrine evaporites around the lake. Salinity profiles in combination with stable isotope and hydraulic data indicate the existence of convection cells and recycled brines. Furthermore restricted ground-water inflow into the lake was detected. Dedolomitisation processes were identified by hydrogeochemical simulations and different brine origins were reproduced by inverse modelling approaches.

Geostatistical and adjoint sensitivity techniques applied to a conceptual model of ground-water flow in the Paradox Basin, Utah

International Nuclear Information System (INIS)

Metcalfe, D.E.; Campbell, J.E.; RamaRao, B.S.; Harper, W.V.; Battelle Project Management Div., Columbus, OH)

1985-01-01

Sensitivity and uncertainty analysis are important components of performance assessment activities for potential high-level radioactive waste repositories. The application of geostatistical and adjoint sensitivity techniques to aid in the calibration of an existing conceptual model of ground-water flow is demonstrated for the Leadville Limestone in Paradox Basin, Utah. The geostatistical method called kriging is used to statistically analyze the measured potentiometric data for the Leadville. This analysis consists of identifying anomalous data and data trends and characterizing the correlation structure between data points. Adjoint sensitivity analysis is then performed to aid in the calibration of a conceptual model of ground-water flow to the Leadville measured potentiometric data. Sensitivity derivatives of the fit between the modeled Leadville potentiometric surface and the measured potentiometric data to model parameters and boundary conditions are calculated by the adjoint method. These sensitivity derivatives are used to determine which model parameter and boundary condition values should be modified to most efficiently improve the fit of modeled to measured potentiometric conditions

Repository site definition in basalt: Pasco Basin, Washington

Energy Technology Data Exchange (ETDEWEB)

Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

1982-03-01

Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi/sup 2/ (5180 km/sup 2/) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process.

Repository site definition in basalt: Pasco Basin, Washington

International Nuclear Information System (INIS)

Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

1982-03-01

Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi 2 (5180 km 2 ) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process

Ground-Water Quality Data in the Central Eastside San Joaquin Basin 2006: Results from the California GAMA Program

Science.gov (United States)

Landon, Matthew K.; Belitz, Kenneth

2008-01-01

Ground-water quality in the approximately 1,695-square-mile Central Eastside study unit (CESJO) was investigated from March through June 2006 as part of the Statewide Basin Assessment Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The study was designed to provide a spatially unbiased assessment of raw ground-water quality within CESJO, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 78 wells in Merced and Stanislaus Counties. Fifty-eight of the 78 wells were selected using a randomized grid-based method to provide statistical representation of the study unit (grid wells). Twenty of the wells were selected to evaluate changes in water chemistry along selected lateral or vertical ground-water flow paths in the aquifer (flow-path wells). The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides and pesticide degradates], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3-trichloropropane (1,2,3-TCP)], inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements], radioactive constituents, and microbial indicators. Naturally occurring isotopes [tritium, carbon-14, and uranium isotopes and stable isotopes of hydrogen, oxygen, nitrogen, sulfur, and carbon], and dissolved noble and other gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected

Environmental Setting and Implications on Water Quality, Upper Colorado River Basin, Colorado and Utah

Science.gov (United States)

Apodaca, Lori E.; Driver, Nancy E.; Stephens, Verlin C.; Spahr, Norman E.

1995-01-01

The Upper Colorado River Basin in Colorado and Utah is 1 of 60 study units selected for water-quality assessment as part of the U.S. Geological Survey's National Water-Quality Assessment program, which began full implementation in 1991. Understanding the environmental setting of the Upper Colorado River Basin study unit is important in evaluating water-quality issues in the basin. Natural and human factors that affect water quality in the basin are presented, including an overview of the physiography, climatic conditions, general geology and soils, ecoregions, population, land use, water management and use, hydrologic characteristics, and to the extent possible aquatic biology. These factors have substantial implications on water-quality conditions in the basin. For example, high concentrations of dissolved solids and selenium are present in the natural background water conditions of surface and ground water in parts ofthe basin. In addition, mining, urban, and agricultural land and water uses result in the presence of certain constituents in the surface and ground water of the basin that can detrimentally affect water quality. The environmental setting of the study unit provides a framework of the basin characteristics, which is important in the design of integrated studies of surface water, ground water, and biology.

Nitrogen Saturation in Highly Retentive Watersheds?

Science.gov (United States)

Daley, M. L.; McDowell, W. H.

2009-12-01

Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

Ground-water quality and its relation to hydrogeology, land use, and surface-water quality in the Red Clay Creek basin, Piedmont Physiographic Province, Pennsylvania and Delaware

Science.gov (United States)

Senior, Lisa A.

1996-01-01

The Red Clay Creek Basin in the Piedmont Physiographic Province of Pennsylvania and Delaware is a 54-square-mile area underlain by a structurally complex assemblage of fractured metamorphosed sedimentary and igneous rocks that form a water-table aquifer. Ground-water-flow systems generally are local, and ground water discharges to streams. Both ground water and surface water in the basin are used for drinking-water supply.Ground-water quality and the relation between ground-water quality and hydrogeologic and land-use factors were assessed in 1993 in bedrock aquifers of the basin. A total of 82 wells were sampled from July to November 1993 using a stratified random sampling scheme that included 8 hydrogeologic and 4 land-use categories to distribute the samples evenly over the area of the basin. The eight hydrogeologic units were determined by formation or lithology. The land-use categories were (1) forested, open, and undeveloped; (2) agricultural; (3) residential; and (4) industrial and commercial. Well-water samples were analyzed for major and minor ions, nutrients, volatile organic compounds (VOC's), pesticides, polychlorinated biphenyl compounds (PCB's), and radon-222.Concentrations of some constituents exceeded maximum contaminant levels (MCL) or secondary maximum contaminant levels (SMCL) established by the U.S. Environmental Protection Agency for drinking water. Concentrations of nitrate were greater than the MCL of 10 mg/L (milligrams per liter) as nitrogen (N) in water from 11 (13 percent) of 82 wells sampled; the maximum concentration was 38 mg/L as N. Water from only 1 of 82 wells sampled contained VOC's or pesticides that exceeded a MCL; water from that well contained 3 mg/L chlordane and 1 mg/L of PCB's. Constituents or properties of well-water samples that exceeded SMCL's included iron, manganese, dissolved solids, pH, and corrosivity. Water from 70 (85 percent) of the 82 wells sampled contained radon-222 activities greater than the proposed MCL of

A basin on an unstable ground: Correlation of the Middle Archaean Moodies Basin, Barberton Greenstone Belt, South Africa

Science.gov (United States)

Ohnemueller, Frank; Heubeck, Christoph; Kirstein, Jens; Gamper, Antonia

2010-05-01

The 3.22 Ga-old Moodies Group, representing the uppermost part of the Barberton Supergroup of the Barberton Greenstone Belt (BGB), is the oldest well-exposed, relatively unmetamorphosed, quartz-rich sedimentary unit on Earth. Moodies facies (north of the Inyoka Fault) were thought to be largely of alluvial, fluvial, deltaic or shallow-marine origin (Anhaeusser, 1976; Eriksson, 1980; Heubeck and Lowe, 1994) and in its upper part syndeformational. However, units can only locally be correlated, and the understanding of the interplay between Moodies sedimentation and deformation is thus limited. We mapped and measured Moodies units in the northern BGB. They partly consist of extensive turbiditic deepwater deposits, including graded bedding, flame structures, and slumped beds, interbedded with jaspilites. These contrast with shallow-water environments, south-facing progressive unconformities and overlying alluvial-fan conglomerates along the northern margin of the Saddleback Syncline further south. The palaeogeographic setting in which late BGB deformation was initiated therefore appears complex and cannot be readily explained by a simple southward-directed shortening event. In order to constrain Moodies basin setting before and during late-Moodies basin collapse, we correlated ~15 measured sections in the northern and central BGB. Most units below the Moodies Lava (MdL, ca. 3230.6+-6 Ma) can be correlated throughout although facies variations are apparent. Above the Moodies Lava, coarse-grained units can only be correlated through the Eureka Syncline and the Moodies Hills Block but not with the Saddleback Syncline. Fine-grained and jaspilitic units can be correlated throughout the northern BGB. Moodies below-wavebase deposition occurred largely north of the Saddleback Fault. The observations are consistent with a pronounced basin compartmentalization event following the eruption of the MdL which appeared to have blanketed most of the Moodies basin(s) in middle Moodies

Air and Ground Surface Temperature Relations in a Mountainous Basin, Wolf Creek, Yukon Territory

Science.gov (United States)

Roadhouse, Emily A.

The links between climate and permafrost are well known, but the precise nature of the relationship between air and ground temperatures remains poorly understood, particularly in complex mountain environments. Although previous studies indicate that elevation and potential incoming solar radiation (PISR) are the two leading factors contributing to the existence of permafrost at a given location, additional factors may also contribute significantly to the existence of mountain permafrost, including vegetation cover, snow accumulation and the degree to which individual mountain landscapes are prone to air temperature inversions. Current mountain permafrost models consider only elevation and aspect, and have not been able to deal with inversion effects in a systematic fashion. This thesis explores the relationship between air and ground surface temperatures and the presence of surface-based inversions at 27 sites within the Wolf Creek basin and surrounding area between 2001 and 2006, as a first step in developing an improved permafrost distribution TTOP model. The TTOP model describes the relationship between the mean annual air temperature and the temperature at the top of permafrost in terms of the surface and thermal offsets (Smith and Riseborough, 2002). Key components of this model are n-factors which relate air and ground climate by establishing the ratio between air and surface freezing (winter) and thawing (summer) degree-days, thus summarizing the surface energy balance on a seasonal basis. Here we examine (1) surface offsets and (2) freezing and thawing n-factor variability at a number of sites through altitudinal treeline in the southern Yukon. Thawing n-factors (nt) measured at individual sites remained relatively constant from one year to the next and may be related to land cover. During the winter, the insulating effect of a thick snow cover results in higher surface temperatures, while thin snow cover results in low surface temperatures more closely

Potential possibilities of water retention in agricultural loess catchments

Directory of Open Access Journals (Sweden)

Zubala Tomasz

2016-09-01

Full Text Available The growing water deficit and the increased demand for water, as well as economic problems and inadequate spatial planning in many regions indicate a necessity of developing more effective rules of programming and realisation of works concerning the water management in small catchments. The paper presents a sample analysis of the possibilities of increasing water retention in the agricultural loess catchments with periodic streams. The scope of the study included the determination of physical parameters of selected sub-catchments (geometry, soil cover, land use, etc. and of the sources of threat to water resources, resulting from construction and geomorphological conditions. Pre-design assumptions of dammings were developed, taking into account anti-erosion protective measures, and treatments increasing the landscape retention of water were proposed. Creating surface retention objects should be an important source of water in simplified agroecosystems, especially in regions, where productivity to a great extent depends on natural weather conditions. Proper management of the fourth-order loess basin of the Ciemięga River (area of about 150 km2, the presence of 50 lateral valleys could give a temporary reservoir retention reaching 500 thousand m3. Farmers should be encouraged to seek “own water sources” (including the accumulation of water within wasteland, using appropriate economic instruments (tax reliefs for the documented volume of retained water, e.g. in small retention reservoirs.

Phosphorus retention in riparian buffers: review of their efficiency.

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Hoffmann, Carl Christian; Kjaergaard, Charlotte; Uusi-Kämppä, Jaana; Hansen, Hans Christian Bruun; Kronvang, Brian

2009-01-01

Ground water and surface water interactions are of fundamental importance for the biogeochemical processes governing phosphorus (P) dynamics in riparian buffers. The four most important conceptual hydrological pathways for P losses from and P retention in riparian buffers are reviewed in this paper: (i) The diffuse flow path with ground water flow through the riparian aquifer, (ii) the overland flow path across the riparian buffer with water coming from adjacent agricultural fields, (iii) irrigation of the riparian buffer with tile drainage water from agricultural fields where disconnected tile drains irrigate the riparian buffer, and (iv) inundation of the riparian buffer (floodplain) with river water during short or longer periods. We have examined how the different flow paths in the riparian buffer influence P retention mechanisms theoretically and from empirical evidence. The different hydrological flow paths determine where and how water-borne P compounds meet and interact with iron and aluminum oxides or other minerals in the geochemical cycling of P in the complex and dynamic environment that constitutes a riparian buffer. The main physical process in the riparian buffer-sedimentation-is active along several flow paths and may account for P retention rates of up to 128 kg P ha(-1) yr(-1), while plant uptake may temporarily immobilize up to 15 kg P ha(-1) yr(-1). Retention of dissolved P in riparian buffers is not as pronounced as retention of particulate P and is often below 0.5 kg P ha(-1) yr(-1). Several studies show significant release of dissolved P (i.e., up to 8 kg P ha(-1) yr(-1)).

KE Basin water dispositioning engineering study

International Nuclear Information System (INIS)

Hunacek, G.S.; Gahir, S.S.

1994-01-01

This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation

Ground-water quality in the carbonate-rock aquifer of the Great Basin, Nevada and Utah, 2003

Science.gov (United States)

Schaefer, Donald H.; Thiros, Susan A.; Rosen, Michael R.

2005-01-01

The carbonate-rock aquifer of the Great Basin is named for the thick sequence of Paleozoic limestone and dolomite with lesser amounts of shale, sandstone, and quartzite. It lies primarily in the eastern half of the Great Basin and includes areas of eastern Nevada and western Utah as well as the Death Valley area of California and small parts of Arizona and Idaho. The carbonate-rock aquifer is contained within the Basin and Range Principal Aquifer, one of 16 principal aquifers selected for study by the U.S. Geological Survey’s National Water- Quality Assessment Program.Water samples from 30 ground-water sites (20 in Nevada and 10 in Utah) were collected in the summer of 2003 and analyzed for major anions and cations, nutrients, trace elements, dissolved organic carbon, volatile organic compounds (VOCs), pesticides, radon, and microbiology. Water samples from selected sites also were analyzed for the isotopes oxygen-18, deuterium, and tritium to determine recharge sources and the occurrence of water recharged since the early 1950s.Primary drinking-water standards were exceeded for several inorganic constituents in 30 water samples from the carbonate-rock aquifer. The maximum contaminant level was exceeded for concentrations of dissolved antimony (6 μg/L) in one sample, arsenic (10 μg/L) in eleven samples, and thallium (2 μg/L) in one sample. Secondary drinking-water regulations were exceeded for several inorganic constituents in water samples: chloride (250 mg/L) in five samples, fluoride (2 mg/L) in two samples, iron (0.3 mg/L) in four samples, manganese (0.05 mg/L) in one sample, sulfate (250 mg/L) in three samples, and total dissolved solids (500 mg/L) in seven samples.Six different pesticides or metabolites were detected at very low concentrations in the 30 water samples. The lack of VOC detections in water sampled from most of the sites is evidence thatVOCs are not common in the carbonate-rock aquifer. Arsenic values for water range from 0.7 to 45.7 �

The impact of cooking and delivery modes of thymol and carvacrol on retention and bioaccessibility in starchy foods.

Science.gov (United States)

Aravena, Gabriela; García, Olga; Muñoz, Ociel; Pérez-Correa, José R; Parada, Javier

2016-04-01

Oregano and thyme possess beneficial properties for human health, mainly attributable to monoterpenes such as thymol and carvacrol. The main objective of this research was to assess, on starchy food, the impact of cooking (boiling and baking) and delivery (ground leaves and essential oil) modes on retention and bioaccessibility of thymol and carvacrol. Retention was assessed after cooking, while bioaccessibility was estimated in cooked samples using an in vitro digestion model. Our results indicate that bioaccessibility was weakly dependent on cooking and delivery modes (27-33%). Boil cooking presented 20% more retention than baking for both compounds. When essential oil was added to the food matrix, thymol was retained almost 25% more when compared with ground leaves' addition. Conversely, carvacrol was retained 39% more when ground leaves were added. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimation of erosion and sedimentation yield in the Ucayali river basin, a Peruvian tributary of the Amazon River, using ground and satellite methods

Science.gov (United States)

Santini, William; Martinez, Jean-Michel; Guyot, Jean-Loup; Espinoza, Raul; Vauchel, Philippe; Lavado, Waldo

2014-05-01

Since 2003, the works of HYBAM observatory (www.ore-hybam.org) has allowed to quantify with accuracy, precision and over a long period Amazon's main rivers discharges and sediments loads. In Peru, a network of 8 stations is regularly gauged and managed in association with the national meteorological and Hydrological service (SENAMHI), the UNALM (National Agrological University of La Molina) and the National Water Agency (ANA). Nevertheless, some current processes of erosion and sedimentation in the foreland basins are still little known, both in volumes and in localization. The sedimentary contributions of Andean tributaries could be there considerable, masking a very strong sedimentation in subsidence zones localized between the control points of the HYBAM's network. The development of spatial techniques such as the Altimetry and reflectance measurement allows us today to complete the ground's network: HYBAM's works have allowed establishing a relation between surface concentration and reflectance in Amazonian rivers (Martinez et al., 2009, Espinoza et al., 2012) and reconstituting water levels series (Calmant et al., 2006, 2008). If the difficulty of calibration of these techniques increases towards the upstream, their use can allow a first characterization of the tributaries contributions and sedimentation zones. At world level, erosion and sedimentation yields in the upper Ucayali are exceptional, favored by a marked seasonality in this region (Espinoza et al., 2009, Lavado, 2010, Pépin et al., 2010) and the presence of cells of extreme precipitation ("Hotspots") (Johnson et al., 1976, Espinoza et al, 2009a). The upper Ucayali drainage basin is a Piggyback where the River run with a low slope, parallel to the Andean range, deposing by gravity hundred millions a year of sands, silts and clays. In this work, we thus propose an estimation of sedimentation and erosion yield in the Ucayali river basin using ground and satellite methods.

Geohydrology and potential effects of coal mining in 12 coal-lease areas, Powder River structural basin, northeastern Wyoming. Water Resources Investigation

International Nuclear Information System (INIS)

Fogg, J.L.; Martin, M.W.; Daddow, P.B.

1991-01-01

The purpose of the report is to describe the geohydrology of 12 coal-lease areas in the Powder River structural basin in relation to the mining proposed for each area. The description of the geohydrology of each of the lease areas focuses on the shallow ground-water system and includes identification of recharge and discharge areas, directions of ground-water movement, and potential effects of mining. The shallow ground-water system in the Powder River structural basin is not well defined because of the discontinuous nature of the aquifers in the basin. Understanding the ground-water hydrology of these 12 coal-lease areas will improve understanding of the shallow ground-water system in the basin. The first part of the report is a description of the general geohydrology of the Wyoming part of the Powder River structural basin. The second part of the report is a general discussion of the effects of coal mining on ground-water hydrology. The third part of the report contains site-specific discussions of the ground-water hydrology and potential effects of mining for each of the 12 coal-lease areas

Ground-Water Hydrology and Projected Effects of Ground-Water Withdrawals in the Sevier Desert, Utah

OpenAIRE

United States Geological Survey

1983-01-01

The principal ground-water reservoir in the Sevier Desert is the unconsolidated basin fill. The fill has been divided generally into aquifers and confining beds, although there are no clearcut boundaries between these units--the primary aquifers are the shallow and deep artesian aquifers. Recharge to the ground-water reservoir is by infiltration of precipitation; seepage from streams, canals, reservoirs, and unconsumed irrigation water; and subsurface inflow from consolidated rocks in mount...

Exploring spatiotemporal changes of the Yangtze River (Changjiang) nitrogen and phosphorus sources, retention and export to the East China Sea and Yellow Sea.

Science.gov (United States)

Liu, Xiaochen; Beusen, Arthur H W; Van Beek, Ludovicus P H; Mogollón, José M; Ran, Xiangbin; Bouwman, Alexander F

2018-06-04

Nitrogen (N) and phosphorus (P) flows from land to sea in the Yangtze River basin were simulated for the period 1900-2010, by combining models for hydrology, nutrient input to surface water, and an in-stream retention. This study reveals that the basin-wide nutrient budget, delivery to surface water, and in-stream retention increased during this period. Since 2004, the Three Gorges Reservoir has contributed 5% and 7% of N and P basin-wide retention, respectively. With the dramatic rise in nutrient delivery, even this additional retention was insufficient to prevent an increase of riverine export from 337 Gg N yr -1 and 58 Gg P yr -1 (N:P molar ratio = 13) to 5896 Gg N yr -1 and 381 Gg P yr -1 (N:P molar ratio = 35) to the East China Sea and Yellow Sea (ECSYS). The midstream and upstream subbasins dominate the N and P exports to the ECSYS, respectively, due to various human activities along the river. Our spatially explicit nutrient source allocation can aid in the strategic targeting of nutrient reduction policies. We posit that these should focus on improving the agricultural fertilizer and manure use efficiency in the upstream and midstream and better urban wastewater management in the downstream subbasin. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Geohydrologic reconnaissance of the upper Potomac River basin

Science.gov (United States)

Trainer, Frank W.; Watkins, Frank A.

1975-01-01

values the frequency of specific capacities of wells is much the same in all rocks in the basin, but high values of specific capacity are as much as 10 times more frequent in carbonate rock than in noncarbonate rock. Nearly all the large springs and high-capacity wells in the basin are in carbonate rock. Base runoff from the carbonate rock is better sustained during dry weather and on the average is about three times as great as base runoff from fractured rock having a thin regolith. The potential role of these water-bearing terranes in water management probably lies in the local development of large water supplies from the carbonate rock and in the possible manipulation of underground storage for such purposes as providing space for artificial recharge of ground water and providing ground water to be used for the augmentation of low streamflow. The chief water-quality problems in the basin--acidic mine-drainage water in the western part of the basin, local highly mineralized ground water, and the high nitrate content of ground water in some of the densely populated parts of the basin--would probably have little adverse affect on the use of ground water for low-flow augmentation.

Regional hydrology of the Dolores River Basin, eastern Paradox Basin, Colorado and Utah

International Nuclear Information System (INIS)

Weir, J.E. Jr.; Maxfield, E.B.; Zimmerman, E.A.

1983-01-01

The Dolores River Basin, is in the eastern part of the Paradox Basin and includes the eastern slope of the La Sal Mountains, the western slopes of the Rico and La Plata Mountains, and the southwest flank of the Uncompahgre Plateau. The climate of this area is more humid than most of the surrounding Colorado Plateau region. Precipitation ranges from slightly 200 mm/yr to 1000 mm/yr; the estimated volume of water falling on the area is 4000 x 10 6 cm 3 /yr. Of this total, about 600 x 10 6 cm 3 /yr is runoff; 190 x 10 6 cm 3 /yr recharges the upper ground-water system; and an estimated 55 x 10 6 cm 3 returns to the atmosphere via evapotranspiration from stream valleys. The remainder evaporates. Principal hydrogeologic units are permeable sandstone and limestone and nearly impermeable salt (halitic) deposits. Structurally, the area is dominated by northwest-trending salt anticlines and contiguous faults paralleled by synclinal structures. The Uncompahgre Plateau lies along the north and northeast sides of the area. The instrusive masses that form the La Sal Mountains are laccoliths with bysmaliths and other complex intrusive forms comprising, in gross form, moderately faulted omal structures. Intrusive rocks underlie the La Plata and Rico Mountains along the southeastern edge of the area. These geologic structures significantly modify ground-water flow patterns in the upper ground-water system, but have no conspicuous effect on the flow regime in the lower ground-water system. The water in the upper ground-water system generally is fresh except where it is affected by evaporite dissolution from salt anticlines. The water of the lower ground-water system is slightly saline to briny. Water quality of the Dolores River is slightly saline to fresh, based on dissolved chemical constituents; some of the smaller tributaries of the river have saline water

Paleohydrogeology of the San Joaquin basin, California

Science.gov (United States)

Wilson, A.M.; Garven, G.; Boles, J.R.

1999-01-01

Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

Water resources of the Yadkin-Pee Dee River Basin, North Carolina

Science.gov (United States)

Fish, Robert Eugene; LeGrand, H.E.; Billingsley, G.A.

1957-01-01

Sufficient water is available in the basin of the Yadkin and Pee Dee Rivers to meet present requirements and those for many years to come if water use increases at about the present rate. Data presented in this report show that the average annual streamflow from approximately 82 percent of the basin area during the 25-year period, 1929-53, was about 6,200 mgd, representing essentially the total available water supply. Comparison of the available water supply to the estimated withdrawal use (excluding water power) of both surface and ground water of 600 mgd indicates the relative utilization of the water resources of the basin at present. If proper pollution controls are observed and practiced so that water in the various streams may be reused several times, the potential water available is even greater than indicated by the above comparison. Preliminary studies indicate that the quantity of water now being withdrawn from ground-water reservoirs in the basin is only a fraction of the total that may be obtained from this source. Twenty-eight of the 64 municipalities having public water-supply systems use surface water; however, as the largest cities in the area use surface supplies, about 85 percent of the water used for public supplies is from surface sources. Of the 20 complete-record stream-gaging stations now in operation in this area 7 have been in operation for 24 years or longer. Periodic measurements of the rate of flow have been made at 31 additional sites on streams scattered widely over the basin. All available streamflow data including those for 1953 are summarized in either graphic or tabular form, or both. Because of the critically low flows occurring during the drought of 1954, several illustrations include data for 1954 and the early months of 1955 for comparison with the minima of previous years. Adequate water for domestic use is available from wells throughout the basin. The consolidated rocks of the Piedmont furnish water for small industries and

Aquifer recharge from infiltration basins in a highly urbanized area: the river Po Plain (Italy)

Science.gov (United States)

Masetti, M.; Nghiem, S. V.; Sorichetta, A.; Stevenazzi, S.; Santi, E. S.; Pettinato, S.; Bonfanti, M.; Pedretti, D.

2015-12-01

Due to the extensive urbanization in the Po Plain in northern Italy, rivers need to be managed to alleviate flooding problems while maintaining an appropriate aquifer recharge under an increasing percentage of impermeable surfaces. During the PO PLain Experiment field campaign in July 2015 (POPLEX 2015), both active and under-construction infiltration basins have been surveyed and analyzed to identify appropriate satellite observations that can be integrated to ground based monitoring techniques. A key strategy is to have continuous data time series on water presence and level within the basin, for which ground based monitoring can be costly and difficult to be obtained consistently.One of the major and old infiltration basin in the central Po Plain has been considered as pilot area. The basin is active from 2003 with ground based monitoring available since 2009 and supporting the development of a calibrated unsaturated-saturated two-dimensional numerical model simulating the infiltration dynamics through the basin.A procedure to use satellite data to detect surface water change is under development based on satellite radar backscatter data with an appropriate incidence angle and polarization combination. An advantage of satellite radar is that it can observe surface water regardless of cloud cover, which can be persistent during rainy seasons. Then, the surface water change is correlated to the reservoir water stage to determine water storage in the basin together with integrated ground data and to give quantitative estimates of variations in the local water cycle.We evaluated the evolution of the infiltration rate, to obtain useful insights about the general recharge behavior of basins that can be used for informed design and maintenance. Results clearly show when the basin becomes progressively clogged by biofilms that can reduce the infiltration capacity of the basin by as much as 50 times compared to when it properly works under clean conditions.

Well installation, single-well testing, and particle-size analysis for selected sites in and near the Lost Creek Designated Ground Water Basin, north-central Colorado, 2003-2004

Science.gov (United States)

Beck, Jennifer A.; Paschke, Suzanne S.; Arnold, L. Rick

2011-01-01

This report describes results from a groundwater data-collection program completed in 2003-2004 by the U.S. Geological Survey in support of the South Platte Decision Support System and in cooperation with the Colorado Water Conservation Board. Two monitoring wells were installed adjacent to existing water-table monitoring wells. These wells were installed as well pairs with existing wells to characterize the hydraulic properties of the alluvial aquifer and shallow Denver Formation sandstone aquifer in and near the Lost Creek Designated Ground Water Basin. Single-well tests were performed in the 2 newly installed wells and 12 selected existing monitoring wells. Sediment particle size was analyzed for samples collected from the screened interval depths of each of the 14 wells. Hydraulic-conductivity and transmissivity values were calculated after the completion of single-well tests on each of the selected wells. Recovering water-level data from the single-well tests were analyzed using the Bouwer and Rice method because test data most closely resembled those obtained from traditional slug tests. Results from the single-well test analyses for the alluvial aquifer indicate a median hydraulic-conductivity value of 3.8 x 10-5 feet per second and geometric mean hydraulic-conductivity value of 3.4 x 10-5 feet per second. Median and geometric mean transmissivity values in the alluvial aquifer were 8.6 x 10-4 feet squared per second and 4.9 x 10-4 feet squared per second, respectively. Single-well test results for the shallow Denver Formation sandstone aquifer indicate a median hydraulic-conductivity value of 5.4 x 10-6 feet per second and geometric mean value of 4.9 x 10-6 feet per second. Median and geometric mean transmissivity values for the shallow Denver Formation sandstone aquifer were 4.0 x 10-5 feet squared per second and 5.9 x 10-5 feet squared per second, respectively. Hydraulic-conductivity values for the alluvial aquifer in and near the Lost Creek Designated

Operational test report for LERF Basin 242AL-44 integrity test

International Nuclear Information System (INIS)

Galioto, T.M.

1994-01-01

This operational test report documents the results of LERF operational testing per operational test procedure (OTP) TFPE-WP-0231, ''LERF Basin Integrity Testing.'' The primary purpose of the OTP was to resolve test exceptions generated as a result of TFPE-WP-0184. The TOP was prepared and performed in accordance with WHC-SD-534-OTP-002, ''Operational Test Plan for the 242-A Evaporator Upgrades and the Liquid Effluent Retention Facility.'' WHC-S-086, ''Specification for Operational Testing of the Liquid Effluent Retention Facility, Basin Integrity Testing,'' identified the test requirements and acceptance criteria. The completed, signed-off test procedure is contained in Appendix A. The test log is contained in Appendix B. Section 2.1 describes all the test exceptions written during performance of the Operational Test Procedure. The test revisions generated during the testing are discussed in Section 2.2. The dispositioned test exception forms are contained in Appendix C

Water-quality assessment of part of the Upper Mississippi River Basin, Minnesota and Wisconsin - Ground-water quality in three different land-use areas, 1996-98

Science.gov (United States)

Fong, Alison L.

2000-01-01

The surficial sand and gravel aquifer is susceptible to effects from land-use in the Upper Mississippi River Basin study unit of the National Water-Quality Assessment (NAWQA) Program. The purpose of this report is to describe the ground-water quality and the assessment of how different land-uses affect the shallow ground-water quality in the surficial sand and gravel aquifer. Ground-water quality was compared in three different land-use areas; an urban residential/commercial area on the edge of the Anoka Sand Plain in a portion of the Twin Cities metropolitan area (urban study), an intensive agricultural area in the Anoka Sand Plain (agricultural study), and a forested area in the Bemidji-Bagley Sand Plain (forested study). Ground water was sampled and analyzed for about 200 constituents, including physical parameters, major ions, selected trace elements, nutrients, dissolved organic carbon, selected pesticides, selected volatile organic compounds (VOCs), and tritium. The urban study wells were sampled during June and July 1996. The agricultural study wells were sampled during May and September 1998. The forested study wells were sampled during June 1998.

Evaluation of site effects in Loja basin (southern Ecuador)

Science.gov (United States)

Guartán, J.; Navarro, M.; Soto, J.

2013-05-01

Site effect assessment based on subsurface ground conditions is often crucial for estimating the urban seismic hazard. In order to evaluate the site effects in the intra-mountain basin of Loja (southern Ecuador), geological and geomorphological survey and ambient noise measurements were carried out. A classification of shallow geologic materials was performed through a geological cartography and the use of geotechnical data and geophysical surveys. Seven lithological formations have been analyzed, both in composition and thickness of existing materials. The shear-wave velocity structure in the center of the basin, composed by alluvial materials, was evaluated by means of inversion of Rayleigh wave dispersion data obtained from vertical-component array records of ambient noise. VS30 structure was estimated and an average value of 346 m s-1 was obtained. This value agrees with the results obtained from SPT N-value (306-368 m s-1). Short-period ambient noise observations were performed in 72 sites on a 500m × 500m dimension grid. The horizontal-to-vertical spectral ratio (HVSR) method was applied in order to determine a ground predominant period distribution map. This map reveals an irregular distribution of predominant period values, ranged from 0.1 to 1.0 s, according with the heterogeneity of the basin. Lower values of the period are found in the harder formation (Quillollaco formation), while higher values are predominantly obtained in alluvial formation. These results will be used in the evaluation of ground dynamic properties and will be included in seismic microzoning of Loja basin. Keywords: Landform classification, Ambient noise, SPAC method, Rayleigh waves, Shear velocity profile, Ground predominant period. ;

Regional Survey of Structural Properties and Cementation Patterns of Fault Zones in the Northern Part of the Albuquerque Basin, New Mexico - Implications for Ground-Water Flow

Science.gov (United States)

Minor, Scott A.; Hudson, Mark R.

2006-01-01

Motivated by the need to document and evaluate the types and variability of fault zone properties that potentially affect aquifer systems in basins of the middle Rio Grande rift, we systematically characterized structural and cementation properties of exposed fault zones at 176 sites in the northern Albuquerque Basin. A statistical analysis of measurements and observations evaluated four aspects of the fault zones: (1) attitude and displacement, (2) cement, (3) lithology of the host rock or sediment, and (4) character and width of distinctive structural architectural components at the outcrop scale. Three structural architectural components of the fault zones were observed: (1) outer damage zones related to fault growth; these zones typically contain deformation bands, shear fractures, and open extensional fractures, which strike subparallel to the fault and may promote ground-water flow along the fault zone; (2) inner mixed zones composed of variably entrained, disrupted, and dismembered blocks of host sediment; and (3) central fault cores that accommodate most shear strain and in which persistent low- permeability clay-rich rocks likely impede the flow of water across the fault. The lithology of the host rock or sediment influences the structure of the fault zone and the width of its components. Different grain-size distributions and degrees of induration of the host materials produce differences in material strength that lead to variations in width, degree, and style of fracturing and other fault-related deformation. In addition, lithology of the host sediment appears to strongly control the distribution of cement in fault zones. Most faults strike north to north-northeast and dip 55? - 77? east or west, toward the basin center. Most faults exhibit normal slip, and many of these faults have been reactivated by normal-oblique and strike slip. Although measured fault displacements have a broad range, from 0.9 to 4,000 m, most are internal structure of, and cement

Water resources in the Big Lost River Basin, south-central Idaho

Science.gov (United States)

Crosthwaite, E.G.; Thomas, C.A.; Dyer, K.L.

1970-01-01

The Big Lost River basin occupies about 1,400 square miles in south-central Idaho and drains to the Snake River Plain. The economy in the area is based on irrigation agriculture and stockraising. The basin is underlain by a diverse-assemblage of rocks which range, in age from Precambrian to Holocene. The assemblage is divided into five groups on the basis of their hydrologic characteristics. Carbonate rocks, noncarbonate rocks, cemented alluvial deposits, unconsolidated alluvial deposits, and basalt. The principal aquifer is unconsolidated alluvial fill that is several thousand feet thick in the main valley. The carbonate rocks are the major bedrock aquifer. They absorb a significant amount of precipitation and, in places, are very permeable as evidenced by large springs discharging from or near exposures of carbonate rocks. Only the alluvium, carbonate rock and locally the basalt yield significant amounts of water. A total of about 67,000 acres is irrigated with water diverted from the Big Lost River. The annual flow of the river is highly variable and water-supply deficiencies are common. About 1 out of every 2 years is considered a drought year. In the period 1955-68, about 175 irrigation wells were drilled to provide a supplemental water supply to land irrigated from the canal system and to irrigate an additional 8,500 acres of new land. Average. annual precipitation ranged from 8 inches on the valley floor to about 50 inches at some higher elevations during the base period 1944-68. The estimated water yield of the Big Lost River basin averaged 650 cfs (cubic feet per second) for the base period. Of this amount, 150 cfs was transpired by crops, 75 cfs left the basin as streamflow, and 425 cfs left as ground-water flow. A map of precipitation and estimated values of evapotranspiration were used to construct a water-yield map. A distinctive feature of the Big Lost River basin, is the large interchange of water from surface streams into the ground and from the

Integrated numerical modeling for basin-wide water management: The case of the Rattlesnake Creek basin in south-central Kansas

Science.gov (United States)

Sophocleous, M.A.; Koelliker, J.K.; Govindaraju, R.S.; Birdie, T.; Ramireddygari, S.R.; Perkins, S.P.

1999-01-01

The objective of this article is to develop and implement a comprehensive computer model that is capable of simulating the surface-water, ground-water, and stream-aquifer interactions on a continuous basis for the Rattlesnake Creek basin in south-central Kansas. The model is to be used as a tool for evaluating long-term water-management strategies. The agriculturally-based watershed model SWAT and the ground-water model MODFLOW with stream-aquifer interaction routines, suitably modified, were linked into a comprehensive basin model known as SWATMOD. The hydrologic response unit concept was implemented to overcome the quasi-lumped nature of SWAT and represent the heterogeneity within each subbasin of the basin model. A graphical user-interface and a decision support system were also developed to evaluate scenarios involving manipulation of water fights and agricultural land uses on stream-aquifer system response. An extensive sensitivity analysis on model parameters was conducted, and model limitations and parameter uncertainties were emphasized. A combination of trial-and-error and inverse modeling techniques were employed to calibrate the model against multiple calibration targets of measured ground-water levels, streamflows, and reported irrigation amounts. The split-sample technique was employed for corroborating the calibrated model. The model was run for a 40 y historical simulation period, and a 40 y prediction period. A number of hypothetical management scenarios involving reductions and variations in withdrawal rates and patterns were simulated. The SWATMOD model was developed as a hydrologically rational low-flow model for analyzing, in a user-friendly manner, the conditions in the basin when there is a shortage of water.

Seismic amplification within the Seattle Basin, Washington State: Insights from SHIPS seismic tomography experiments

Science.gov (United States)

Snelson, C.M.; Brocher, T.M.; Miller, K.C.; Pratt, T.L.; Trehu, A.M.

2007-01-01

Recent observations indicate that the Seattle sedimentary basin, underlying Seattle and other urban centers in the Puget Lowland, Washington, amplifies long-period (1-5 sec) weak ground motions by factors of 10 or more. We computed east-trending P- and S-wave velocity models across the Seattle basin from Seismic Hazard Investigations of Puget Sound (SHIPS) experiments to better characterize the seismic hazard the basin poses. The 3D tomographic models, which resolve features to a depth of 10 km, for the first time define the P- and S-wave velocity structure of the eastern end of the basin. The basin, which contains sedimentary rocks of Eocene to Holocene, is broadly symmetric in east-west section and reaches a maximum thickness of 6 km along our profile beneath north Seattle. A comparison of our velocity model with coincident amplification curves for weak ground motions produced by the 1999 Chi-Chi earthquake suggests that the distribution of Quaternary deposits and reduced velocity gradients in the upper part of the basement east of Seattle have significance in forecasting variations in seismic-wave amplification across the basin. Specifically, eastward increases in the amplification of 0.2- to 5-Hz energy correlate with locally thicker unconsolidated deposits and a change from Crescent Formation basement to pre-Tertiary Cascadia basement. These models define the extent of the Seattle basin, the Seattle fault, and the geometry of the basement contact, giving insight into the tectonic evolution of the Seattle basin and its influence on ground shaking.

Modeling of the loss of soil by water erosion of the basin of the River V Anniversary Cuyaguateje

International Nuclear Information System (INIS)

Alonso, Gustavo R.; Días, Jorge; Ruíz, Maria Elena

2008-01-01

The complexity of the processes involved in water erosion of soils has led to widespread use of models with high level of empiricism. However, there are few applications based on models with a considerable physical basis in this field. The purpose of this work is to evaluate the potential of a model of physical basis for estimating soil loss by erosion basin-scale and analyze the behavior of the variables in this model response. The study area was located in the Sub-basin V anniversary, which belongs to the basin of the Cuyaguateje, in the province of Pinar de Rio. You were a database of physical properties of main soils of the basin, the series-temporales of solid spending and runoff measured at River, and rain recorded by a network of rain gauges across the basin. The equation of physical basis used was the sediment transport model (STM), according to Biesemans (2000). As input variables of the model were obtained the following maps: the digital elevation model, accumulative area of drainage, drainage, land use, surface water retention capacity, retention of moisture and hydraulic conductivity of saturation curve. Soil loss was obtained per pixel, and these were correlated with each time series. The results show that the process can be extended to other sub-basins without the need to validate all the variables involved

Evaluation of uranium anomalies in the Hylas zone and northern Richmond basin, east-central Virginia

International Nuclear Information System (INIS)

Baillieul, T.A.; Dexter, J.J.

1982-01-01

Conclusions from this study are: (1) Radon values in ground water from the Hylas Zone and the adjacent Richmomd Basin are anomalous and may indicate nearby uranium-enriched source rocks. (2) Pegmatites, protomylonitic granite, and the Petersburg Granite can be good sources of uranium for ground water. The pegmatites described in this report appear to be the best source rocks because of uranium values ranging from 82 to 235 ppM eU and corresponding low values of Th as well (average Th/U = 0.18). The protomylonitic granite has an average Th/U ratio of 0.5. Ground-water samples (ranging from 70 to 270 ppB uranium) from southwest Richmond are believed to have originated from a major ground-water system at the contact of the Petersburg Granite and overlying coastal plain sediments. Thus, the Petersburg Granite may be considered a possible source of uranium available to ground water entering the Richmond Basin. (3) The Richmond Basin could host uranium deposits of the sandstone class. As mentioned above, there appears to be an adequate supply of uranium in rocks surrounding the basin. The basin environment is presently classified as unevaluated. Further work is warranted on the basis of this study. (4) Pegmatites in the Hylas Zone could be favorable for the occurrence of uranium deposits of the pegmatitic class. However, it is not known how the uranium occurs in the pegmatites, and only pegmatites exposed in the Boscobel quarry were examined. Therefore, this environment remains unevaluated. 3 figures, 4 tables

Biotic diversity interfaces with urbanization in the Lake Tahoe basin

Science.gov (United States)

Patricia N. Manley; Dennis D. Murphy; Lori A. Campbell; Kirsten E. Heckmann; Susan Merideth; Sean A. Parks; Monte P. Sanford; Matthew D. Schlesinger

2006-01-01

In the Lake Tahoe Basin, the retention of native ecosystems within urban areas may greatly enhance the landscape’s ability to maintain biotic diversity. Our study of plant, invertebrate and vertebrate species showed that many native species were present in remnant forest stands in developed areas; however, their richness and abundance declined in association with...

Northern part, Ten Mile and Taunton River basins

Science.gov (United States)

Williams, John R.; Willey, Richard E.

1967-01-01

The northern part of the Ten Mile and Taunton River basins is an area of about 195 square miles within Norfolk, Plymouth, and Bristol Counties in southeastern Massachusetts. The northern boundary of the area (plate 1) is the drainage divide separating these basins from that of the Charles, Neponset, and Weymouth River basins. The western boundary is, for the most part, the divide separating the basins from the Blackstone River basin. The eastern boundary is at the edge of the Brockton-Pembroke area (Petersen, 1962; Petersen and Shaw, 1961). The southern boundary in Seekonk is the northern limit of the East Providence quadrangle, for which a ground-water map was prepared by Allen and Gorman (1959); eastward, the southern boundaries of the city of Attleboro and the towns of Norton, Easton, and West Bridgewater form the southern boundary of the area.

Meteorological, stream-discharge, and water-quality data for water year 1992 from two basins in Central Nevada

International Nuclear Information System (INIS)

McKinley, P.W.; Oliver, T.A.

1995-01-01

The US Geological Survey, in cooperation with the US Department of Energy, is studying Yucca Mountain, Nevada, as a potential repository for high level nuclear waste. As part of the Yucca Mountain Site Project, the analog recharge study is providing data for the evaluation of recharge to the Yucca Mountain ground-water system given a cooler and wetter climate than currently exists. The current and climatic conditions are favorable to the isolation of radioactive waste. Because waste isolation from the accessible environment for 10,000 years is necessary, climatic change and the potential for increased ground-water recharge need to be considered as part of the characterization of the potential repository. Therefore, two small basins, measuring less than 2 square miles, were studied to determine the volume of precipitation available for recharge to ground water. The semiarid 3-Springs Basin is located to the east of Kawich Peak in the Kawich Range east of Tonopah, Nevada. Stewart Basin is a subalpine drainage basin north of Arc Dome in the Toiyabe Range north of Tonopah, Nevada. The purpose of this publication is to make available the meteorological, stream-discharge, and water-quality data collected during the study. Meteorological data collected include air temperature, soil temperature, solar radiation, and relative humidity. Stream-discharge data were collected from the surface-water outlet of each basin. Water-quality data are chemical analyses of water samples collected from surface- and ground-water sources. Each basin has a meteorological station located in the lower and upper reaches of the basin. Hydrologic records include stream-discharge and water-quality data from the lower meteorological site and water-quality data from springs within the basins

CENTRAL NIGERIA: DEDUCTIONS FROM GROUND MAGNETIC

African Journals Online (AJOL)

Magnetic field data of the K uri River basin were obtained from a ground magnetic survey using an MP-2 proton ... These shapes conform to the concept of the ... Granite Complex in the South west (Fig. 1). ..... Cross-section: It's Properties and.

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume I. Dalhart Basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and highly variable prcipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Study on soil-water retention curves for loess aerated zone

International Nuclear Information System (INIS)

Guo Zede; Cheng Jinru; Deng An; Masayuki Mukai; Hideo Kamiyama

2000-01-01

The author introduces the measuring method and results of soil-water retention curves of 46 samples taken from ground surface to water table of 28 m depth at CIRP's Field Test Site. The results indicate that the soil-water retention characteristics vary significantly with depth, and the loess-aerated zone at the site can be divided into five layers. From the results, unsaturated hydraulic parameters are deduced, such as conductivity, specific water capacity and equivalent pore diameter. The water velocity calculated from these parameters is satisfactorily consistent with that one obtained from 3 H tracing test carried out at the site

Analysis of the Carmel Valley alluvial ground-water basin, Monterey County, California

Science.gov (United States)

Kapple, Glenn W.; Mitten, Hugh T.; Durbin, Timothy J.; Johnson, Michael J.

1984-01-01

A two-dimensional, finite-element, digital model was developed for the Carmel Valley alluvial ground-water basin using measured, computed, and estimated discharge and recharge data for the basin. Discharge data included evapotranspiration by phreatophytes and agricultural, municipal, and domestic pumpage. Recharge data included river leakage, tributary runoff, and pumping return flow. Recharge from subsurface boundary flow and rainfall infiltration was assumed to be insignificant. From 1974 through 1978, the annual pumping rate ranged from 5,900 to 9,100 acre-feet per year with 55 percent allotted to municipal use principally exported out of the valley, 44 percent to agricultural use, and 1 percent to domestic use. The pumpage return flow within the valley ranged from 900 to 1,500 acre-feet per year. The aquifer properties of transmissivity (about 5,900 feet squared per day) and of the storage coefficient (0.19) were estimated from an average alluvial thickness of 75 feet and from less well-defined data on specific capacity and grain-size distribution. During calibration the values estimated for hydraulic conductivity and storage coefficient for the lower valley were reduced because of the smaller grain size there. The river characteristics were based on field and laboratory analyses of hydraulic conductivity and on altitude survey data. The model is intended principally for simulation of flow conditions using monthly time steps. Time variations in transmissivity and short-term, highrecharge potential are included in the model. The years 1974 through 1978 (including "pre-" and "post-" drought) were selected because of the extreme fluctuation in water levels between the low levels measured during dry years and the above-normal water levels measured during the preceding and following wet years. Also, during this time more hydrologic information was available. Significantly, computed water levels were generally within a few feet of the measured levels, and computed

NO2 DOAS measurements from ground and space: comparison of ground based measurements and OMI data in Mexico City

Science.gov (United States)

Rivera, C.; Stremme, W.; Grutter, M.

2012-04-01

The combination of satellite data and ground based measurements can provide valuable information about atmospheric chemistry and air quality. In this work we present a comparison between measured ground based NO2 differential columns at the Universidad Nacional Autónoma de México (UNAM) in Mexico City, using the Differential Optical Absorption Spectroscopy (DOAS) technique and NO2 total columns measured by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite using the same measurement technique. From these data, distribution maps of average NO2 above the Mexico basin were constructed and hot spots inside the city could be identified. In addition, a clear footprint was detected from the Tula industrial area, ~50 km northwest of Mexico City, where a refinery, a power plant and other industries are located. A less defined footprint was identified in the Cuernavaca basin, South of Mexico City, and the nearby cities of Toluca and Puebla do not present strong enhancements in the NO2 total columns. With this study we expect to cross-validate space and ground measurements and provide useful information for future studies.

Ecohydrological Controls on Intra-Basin Alpine Subarctic Water Balances

Science.gov (United States)

Carey, S. K.; Ziegler, C. M.

2007-12-01

In the mountainous Canadian subarctic, elevation gradients control the disposition of vegetation, permafrost, and characteristics of the soil profile. How intra-basin ecosystems combine to control catchment-scale water and biogeochimcal cycling is uncertain. To this end, a multi-year ecohydrological investigation was undertaken in Granger Basin (GB), a 7.6 km2 sub-basin of the Wolf Creek Research Basin, Yukon Territory, Canada. GB was divided into four sub-basins based on the dominant vegetation and permafrost status, and the timing and magnitude of hydrological processes were compared using hydrometric and hydrochemical methods. Vegetation plays an important role in end-of-winter snow accumulation as snow redistribution by wind is controlled by roughness length. In sub-basins of GB with tall shrubs, snow accumulation is enhanced compared with areas of short shrubs and tundra vegetation. The timing of melt was staggered with elevation, although melt-rates were similar among the sub-basins. Runoff was enhanced at the expense of infiltration in tall shrub areas due to high snow water equivalent and antecedent soil moisture. In the high-elevation tundra sub-basin, thin soils with cold ground temperatures resulted in increased surface runoff. For the freshet period, the lower and upper sub-basins accounted for 81 % of runoff while accounting for 58 % of the total basin area. Two-component isotopic hydrograph separation revealed that during melt, pre-event water dominated in all sub-basins, yet those with greater permafrost disposition and taller shrubs had increased event-water. Dissolved organic carbon (DOC) spiked prior to peak freshet in each sub-basin except for the highest with thin soils, and was associated with flushing of surficial organic soils. For the post-melt period, all sub-basins have similar runoff contributions. Solute and stable isotope data indicate that in sub-basins dominated by permafrost, supra-permafrost runoff pathways predominate as flow

Assessment of groundwater potential in Ankobra River Basin

International Nuclear Information System (INIS)

Nyarkoh, Charles Prince

2011-08-01

Ankobra river basin is endowed with many rich natural resources. The mining activities in the basin and the proposed hydropower generation on the Ankobra river as well as oil discovery in the Western Region would lead to the establishing of new industries in the basin. These would certainly lead to potential population growth. As a result of these developments, there would be stress on surface water resources and therefore there would be demand for ground water. A research was carried out to assess groundwater supply. Hydrogeological data was used to evaluate the ground water storage in the basement complex, regolith. The relevant aquifer characteristics/parameters (extent of the study area, thickness of the ground water zone in the regolith, the porosity and specific capacity of the aquifer zones) were used to compute total groundwater storage and recoverable storage. The groundwater contribution to stream flow was computed using mean monthly discharge data from the filled data and hydrograph drawn. The base flow was then determined from the hydrograph separation using the straight line method. The groundwater potential in the Ankobra basin is 45.82*10 9 m 3 while the recoverable groundwater storage is 29.39*10 9 m 3 . The base flow computed was 13.75m 3/ s. Investigations into groundwater chemistry with particular references to physico-chemical parameters (quality) was analysed. The constituents fall within the acceptable limits of the Ghana Standard Board (GSB) for drinking water standard and are satisfactory for human consumption. However, Tamso, Wantenem, Gyaman, Beyim communities exceeded the GSB'S recommended values of PH (6.5-8.5) and chloride ( 250 mg/I) respectively for drinking water standard.(author)

Geographic, geologic, and hydrologic summaries of intermontane basins of the northern Rocky Mountains, Montana

Science.gov (United States)

Kendy, Eloise; Tresch, R.E.

1996-01-01

This report combines a literature review with new information to provide summaries of the geography, geology, and hydrology of each of 32 intermontane basins in western Montana. The summary of each intermontane basin includes concise descriptions of topography, areal extent, altitude, climate, 1990 population, land and water use, geology, surface water, aquifer hydraulic characteristics, ground-water flow, and ground-water quality. If present, geothermal features are described. Average annual and monthly temperature and precipitation are reported from one National Weather Service station in each basin. Streamflow data, including the drainage area, period of record, and average, minimum, and maximum historical streamflow, are reported for all active and discontinued USGS streamflow-gaging stations in each basin. Monitoring-well data, including the well depth, aquifer, period of record, and minimum and maximum historical water levels, are reported for all long-term USGS monitoring wells in each basin. Brief descriptions of geologic, geophysical, and potentiometric- surface maps available for each basin also are included. The summary for each basin also includes a bibliography of hydrogeologic literature. When used alone or in conjunction with regional RASA reports, this report provides a practical starting point for site-specific hydrogeologic investigations.

MONTHLY AVERAGE FLOW IN RÂUL NEGRU HYDROGRAPHIC BASIN

Directory of Open Access Journals (Sweden)

VIGH MELINDA

2014-03-01

Full Text Available Râul Negru hydrographic basin represents a well individualised and relatively homogenous physical-geographical unity from Braşov Depression. The flow is controlled by six hydrometric stations placed on the main collector and on two of the most powerful tributaries. Our analysis period is represented by the last 25 years (1988 - 2012 and it’s acceptable for make pertinent conclusions. The maximum discharge month is April, that it’s placed in the high flow period: March – June. Minimum discharges appear in November - because of the lack of pluvial precipitations; in January because of high solid precipitations and because of water volume retention in ice. Extreme discharge frequencies vary according to their position: in the mountain area – small basin surface; into a depression – high basin surface. Variation coefficients point out very similar variation principles, showing a relative homogeneity of flow processes.

Upper Illinois River basin

Science.gov (United States)

Friedel, Michael J.

1998-01-01

During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

Use of real-time monitoring to predict concentrations of select constituents in the Menomonee River drainage basin, Southeast Wisconsin, 2008-9

Science.gov (United States)

Baldwin, Austin K.; Graczyk, David J.; Robertson, Dale M.; Saad, David A.; Magruder, Christopher

2012-01-01

The Menomonee River drainage basin in southeast Wisconsin is undergoing changes that may affect water quality. Several rehabilitation and flood-management projects are underway, including removal of concrete channels and the construction of floodwater retention basins. The city of Waukesha may begin discharging treated wastewater into Underwood Creek, thus approximately doubling the current base-flow discharge. In addition, the headwater basins, historically dominated by agriculture and natural areas, are becoming increasingly urbanized.

Area environmental characterization report of the Dalhart and Palo Duro basins in the Texas Panhandle. Volume II. Palo Duro basin

International Nuclear Information System (INIS)

1982-09-01

This area report describes the environmental characteristics of the Dalhart and Palo Duro basins of the Texas Panhandle portion of the Permian basin. Both basins are rather sparsely populated, and the overall population is decreasing. The economic base is centered on agribusiness and manufacturing. Most of the potentially conflicting land uses in both basins (i.e., parks, historic sites) occupy small land areas, with the exception of a national grassland in the Dalhart and military air training routes in both basins. Ground transportation in the Dalhart basin is adequate, and it is well developed in the Palo Duro basin. In both basins irrigation constitutes the principal water use, and groundwater is the principal source. However, the dominant aquifer, the Ogallala, is being depleted. Both basins consist primarily of grasslands, rangelands, and agricultural areas. No critical terrestrial or aquatic habitats have been identified in the basins, though several endangered, threatened, or rare terrestrial species occur in or near the basins. Aquatic resources in both basins are limited because of the intermittent availability of water and the high salt content of some water bodies. Playa lakes are common, though usually seasonal or rain dependent. The climate of the area is semiarid, with low humidity, relatively high wind speeds, and high variable precipitation. Restrictive dispersion conditions are infrequent. National ambient secondary air quality standards for particulates are being exceeded in the area, largely because of fugitive dust, although there are some particulate point sources

Hydrogeology, water quality, and potential for contamination of the Upper Floridan aquifer in the Silver Springs ground-water basin, central Marion County, Florida

Science.gov (United States)

Phelps, G.G.

1994-01-01

The Upper Floridan aquifer, composed of a thick sequence of very porous limestone and dolomite, is the principal source of water supply in the Silver Springs ground-water basin of central Marion County, Florida. The karstic nature of the local geology makes the aquifer susceptible to contaminants from the land surface. Contaminants can enter the aquifer by seepage through surficial deposits and through sinkholes and drainage wells. Potential contaminants include agricultural chemicals, landfill leachates and petroleum products from leaking storage tanks and accidental spills. More than 560 sites of potential contamination sources were identified in the basin in 1990. Detailed investigation of four sites were used to define hydrologic conditions at representative sites. Ground-water flow velocities determined from dye trace studies ranged from about 1 foot per hour under natural flow conditions to about 10 feet per hour under pumping conditions, which is considerably higher than velocities estimated using Darcy's equation for steady-state flow in a porous medium. Water entering the aquifer through drainage wells contained bacteria, elevated concentrations of nutrients, manganese and zinc, and in places, low concentrations of organic compounds. On the basis of results from the sampling of 34 wells in 1989 and 1990, and from the sampling of water entering the Upper Floridan aquifer through drainage wells, there has been no widespread degradation of water quality in the study area. In an area of karst, particularly one in which fracture flow is significant, evaluating the effects from contaminants is difficult and special care is required when interpolating hydrogeologic data from regional studies to a specific. (USGS)

Ground-water quality in the Appalachian Plateaus, Kanawha River basin, West Virginia

Science.gov (United States)

Sheets, Charlynn J.; Kozar, Mark D.

2000-01-01

Water samples collected from 30 privately-owned and small public-supply wells in the Appalachian Plateaus of the Kanawha River Basin were analyzed for a wide range of constituents, including bacteria, major ions, nutrients, trace elements, radon, pesticides, and volatile organic compounds. Concentrations of most constituents from samples analyzed did not exceed U.S. Environmental Protection Agency (USEPA) standards. Constituents that exceeded drinking-water standards in at least one sample were total coliform bacteria, Escherichia coli (E. coli), iron, manganese, and sulfate. Total coliform bacteria were present in samples from five sites, and E. coli were present at only one site. USEPA secondary maximum contaminant levels (SMCLs) were exceeded for three constituents -- sulfate exceeded the SMCL of 250 mg/L (milligrams per liter) in samples from 2 of 30 wells; iron exceeded the SMCL of 300 ?g/L (micrograms per liter) in samples from 12 of the wells, and manganese exceeded the SMCL of 50 ?g/L in samples from 17 of the wells sampled. None of the samples contained concentrations of nutrients that exceeded the USEPA maximum contaminant levels (MCLs) for these constituents. The maximum concentration of nitrate detected was only 4.1 mg/L, which is below the MCL of 10 mg/L. Concentrations of nitrate in precipitation and shallow ground water are similar, potentially indicating that precipitation may be a source of nitrate in shallow ground water in the study area. Radon concentrations exceeded the recently proposed maximum contaminant level of 300 pCi/L at 50 percent of the sites sampled. The median concentration of radon was only 290 pCi/L. Radon-222 is a naturally occurring, carcinogenic, radioactive decay product of uranium. Concentrations, however, did not exceed the alternate maximum contaminant level (AMCL) for radon of 4,000 pCi/L in any of the 30 samples. Arsenic concentrations exceeded the proposed MCL of 5?g/L at 4 of the 30 sites. No samples exceeded the

18 CFR 430.19 - Ground water withdrawal metering, recording, and reporting.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Ground water withdrawal metering, recording, and reporting. 430.19 Section 430.19 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.19...

Hydrogeologic reconnaissance of the San Miguel River basin, southwestern Colorado

Science.gov (United States)

Ackerman, D.J.; Rush, F.E.

1984-01-01

The San Miguel River Basin encompasses 4,130 square kilometers of which about two-thirds is in the southeastern part of the Paradox Basin. The Paradox Basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Evaporite beds of mostly salt are both overlain and underlain by confining beds. Aquifers are present above and below the confining-bed sequence. The principal element of ground-water outflow from the upper aquifer is flow to the San Miguel River and its tributaries; this averages about 90 million cubic meters per year. A water budget for the lower aquifer has only two equal, unestimated elements, subsurface outflow and recharge from precipitation. The aquifers are generally isolated from the evaporite beds by the bounding confining beds; as a result, most ground water has little if any contact with the evaporites. No brines have been sampled and no brine discharges have been identified in the basin. Salt water has been reported for petroleum-exploration wells, but no active salt solution has been identified. (USGS)

Realistic modelling of observed seismic motion in complex sedimentary basins

International Nuclear Information System (INIS)

Faeh, D.; Panza, G.F.

1994-03-01

Three applications of a numerical technique are illustrated to model realistically the seismic ground motion for complex two-dimensional structures. First we consider a sedimentary basin in the Friuli region, and we model strong motion records from an aftershock of the 1976 earthquake. Then we simulate the ground motion caused in Rome by the 1915, Fucino (Italy) earthquake, and we compare our modelling with the damage distribution observed in the town. Finally we deal with the interpretation of ground motion recorded in Mexico City, as a consequence of earthquakes in the Mexican subduction zone. The synthetic signals explain the major characteristics (relative amplitudes, spectral amplification, frequency content) of the considered seismograms, and the space distribution of the available macroseismic data. For the sedimentary basin in the Friuli area, parametric studies demonstrate the relevant sensitivity of the computed ground motion to small changes in the subsurface topography of the sedimentary basin, and in the velocity and quality factor of the sediments. The total energy of ground motion, determined from our numerical simulation in Rome, is in very good agreement with the distribution of damage observed during the Fucino earthquake. For epicentral distances in the range 50km-100km, the source location and not only the local soil conditions control the local effects. For Mexico City, the observed ground motion can be explained as resonance effects and as excitation of local surface waves, and the theoretical and the observed maximum spectral amplifications are very similar. In general, our numerical simulations permit the estimate of the maximum and average spectral amplification for specific sites, i.e. are a very powerful tool for accurate micro-zonation. (author). 38 refs, 19 figs, 1 tab

Knowledge and Understanding of the Hydrogeology of the Salt Basin in South-Central New Mexico and Future Study Needs

Science.gov (United States)

Huff, G.F.; Chace, D.A.

2006-01-01

The Salt Basin covers about 2,400 square miles of south-central New Mexico and extends across the State line into Texas. As much as 57 million acre-feet of ground water may be stored within the New Mexico part of the Salt Basin of which 15 million acre-feet are potentially potable and recoverable. Recent work suggests that the volume of ground water in storage within the New Mexico portion of the Salt Basin may be substantially greater than 57 million acre-feet. In this report, aquifers contained in the San Andres, Bone Spring, and Victorio Peak Limestones and in the Yeso, Hueco, and Abo Formations are collectively referred to as the carbonate aquifer. Porosity and permeability of the major aquifer are primarily determined by the density and interconnectedness of fractures and karstic solution channels. The spatial variability of these fractures and karstic features leads to a large spatial variability in hydraulic properties in the carbonate aquifer. Ground water generally moves southward away from recharge areas along the northern border of the Salt Basin and generally moves eastward to southeastward away from areas of distributed recharge on the Otero Mesa and the Diablo Plateau. Ground water originating from these recharge areas generally moves toward the central valley. Present day discharge is mostly through ground-water withdrawal for agricultural irrigation. A zone of relatively low hydraulic gradient, corresponding to the location of the Otero Break, extends from near the Sacramento River watershed southward toward Dell City, Texas. Ground water in the carbonate aquifer generally is very hard and has dissolved-solids concentrations ranging from 500 to 6,500 milligrams per liter. Substantial variability exists in current estimates of (1) ground-water recharge, (2) natural ground-water discharge, (3) the volume of ground water in storage, (4) the volume of recoverable ground water, (5) the conceptual model of ground-water flow, (6) the distribution of ground

Hydrogeologic setting, water budget, and preliminary analysis of ground-water exchange at Lake Starr, a seepage lake in Polk County, Florida

Science.gov (United States)

Swancar, Amy; Lee, T.M.; O'Hare, T. M.

2000-01-01

Lake Starr, a 134-acre seepage lake of multiple-sinkhole origin on the Lake Wales Ridge of central Florida, was the subject of a detailed water-budget study from August 1996 through July 1998. The study monitored the effects of hydrogeologic setting, climate, and ground-water pumping on the water budget and lake stage. The hydrogeologic setting of the Lake Starr basin differs markedly on the two sides of the lake. Ground water from the surficial aquifer system flows into the lake from the northwest side of the basin, and lake water leaks out to the surficial aquifer system on the southeast side of the basin. Lake Starr and the surrounding surficial aquifer system recharge the underlying Upper Floridan aquifer. The rate of recharge to the Upper Floridan aquifer is determined by the integrity of the intermediate confining unit and by the downward head gradient between the two aquifers. On the inflow side of the lake, the intermediate confining unit is more continuous, allowing ground water from the surficial aquifer system to flow laterally into the lake. Beneath the lake and on the southeast side of the basin, breaches in the intermediate confining unit enhance downward flow to the Upper Floridan aquifer, so that water flows both downward and laterally away from the lake through the ground-water flow system in these areas. An accurate water budget, including evaporation measured by the energy-budget method, was used to calculate net ground-water flow to the lake, and to do a preliminary analysis of the relation of net ground-water fluxes to other variables. Water budgets constructed over different timeframes provided insight on processes that affect ground-water interactions with Lake Starr. Weekly estimates of net ground-water flow provided evidence for the occurrence of transient inflows from the nearshore basin, as well as the short-term effects of head in the Upper Floridan aquifer on ground-water exchange with the lake. Monthly water budgets showed the effects

A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

International Nuclear Information System (INIS)

Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A.; Myer, L.; Pellerin, L.; Pruess, K.

1996-11-01

This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ( 137 Cs, 90 Sr, and 238 Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and geophysical methods, was developed. A lance water injection test was conducted in order to obtain representative estimates of the hydraulic conductivity and its distribution for the design of the barrier emplacement. The water injection test demonstrated the lack of permeable zones for CS injection, and a decision not to proceed with the barrier emplacement was reached

Isotopic investigation of ground water resources in the Ojo Alamo sandstone, Nacimiento, and San Jose Formations, San Juan Basin, New Mexico. Technical completion report

International Nuclear Information System (INIS)

Phillips, F.M.; Peeters, L.A.; Tansey, M.K.

1984-06-01

The San Juan Basin, in northwest New Mexico, has vast reserves of strippable, low-sulfur coal. Development of the resource will require large quantities of water, from an area where water resources are not abundant. Since surface-water supplies are fully allocated, increased future water demands will have to be met through ground-water development. The study concentrates on the Ojo Alamo, Nacimiento, and San Jose Formations, the aquifers directly above the principal coal unit. Carbon-14 and tritium methods were used to date the ground water in these units. Initial radiocarbon activities were calculated using the models of Vogel, Tamers, Pearson, Mook and Fontes. The observation lends support to the hypothesis of isotopically lighter Pleistocene precipitation. Such lighter recharge was most likely due to a colder mean annual temperature and perhaps increased winter precipitation. A similar change is obtained from noble-gas paleothermometry

Seasonal thaw settlement at drained thermokarst lake basins, Arctic Alaska

Science.gov (United States)

Liu, Lin; Schaefer, Kevin; Gusmeroli, Alessio; Grosse, Guido; Jones, Benjamin M.; Zhang, Tinjun; Parsekian, Andrew; Zebker, Howard

2014-01-01

Drained thermokarst lake basins (DTLBs) are ubiquitous landforms on Arctic tundra lowland. Their dynamic states are seldom investigated, despite their importance for landscape stability, hydrology, nutrient fluxes, and carbon cycling. Here we report results based on high-resolution Interferometric Synthetic Aperture Radar (InSAR) measurements using space-borne data for a study area located on the North Slope of Alaska near Prudhoe Bay, where we focus on the seasonal thaw settlement within DTLBs, averaged between 2006 and 2010. The majority (14) of the 18 DTLBs in the study area exhibited seasonal thaw settlement of 3–4 cm. However, four of the DTLBs examined exceeded 4 cm of thaw settlement, with one basin experiencing up to 12 cm. Combining the InSAR observations with the in situ active layer thickness measured using ground penetrating radar and mechanical probing, we calculated thaw strain, an index of thaw settlement strength along a transect across the basin that underwent large thaw settlement. We found thaw strains of 10–35% at the basin center, suggesting the seasonal melting of ground ice as a possible mechanism for the large settlement. These findings emphasize the dynamic nature of permafrost landforms, demonstrate the capability of the InSAR technique to remotely monitor surface deformation of individual DTLBs, and illustrate the combination of ground-based and remote sensing observations to estimate thaw strain. Our study highlights the need for better description of the spatial heterogeneity of landscape-scale processes for regional assessment of surface dynamics on Arctic coastal lowlands.

Natural flood retention in mountain areas by forests and forest like short rotation coppices

Science.gov (United States)

Reinhardt-Imjela, Christian; Schulte, Achim; Hartwich, Jens

2017-04-01

Natural water retention is an important element of flood risk management in flood generating headwater areas in the low mountain ranges of Central Europe. In this context forests are of particular interest because of the high infiltration capacities of the soils and to increase water retention reforestation of agricultural land would be worthwhile. However competing claims for land use in intensely cultivated regions in Central Europe impede reforestation plans so the potential for a significant increase of natural water retention in forests is strongly limited. Nevertheless the development of innovative forms of land use and crop types opens new perspectives for a combination of agricultural land use with the water retention potential of forests. Recently the increasing demand for renewable energy resources leads to the cultivation of fast growing poplar and willow hybrids on agricultural land in short rotation coppices (SRC). Harvested in cycles of three to six years the wood from the plantations can be used as wood chips for heat and electricity production in specialized power plants. With short rotation plantations a crop type is established on arable land which is similar to forests so that an improvement of water retention can be expected. To what extend SRC may contribute to flood attenuation in headwater areas is investigated for the Chemnitzbach watershed (48 km2) in the Eastern Ore Mountains (Free State of Saxony, Germany), a low mountain range which is an important source of flood runoff in the Elbe basin. The study is based on a rainfall-runoff model of flood events using the conceptual modelling system NASIM. First results reveal a significant reduction of the flood peaks after the implementation of short rotation coppices. However the effect strongly depends on two factors. The first factor is the availability of areas for the plantations. For a substantial impact on the watershed scale large areas are required and with decreasing percentages of SRC

An economic assessment of local farm multi-purpose surface water retention systems in a Canadian Prairie setting

Science.gov (United States)

Berry, Pamela; Yassin, Fuad; Belcher, Kenneth; Lindenschmidt, Karl-Erich

2017-12-01

There is a need to explore more sustainable approaches to water management on the Canadian Prairies. Retention pond installation schemes designed to capture surface water may be a viable option that would reduce water stress during drought periods by providing water for irrigation. The retention systems would serve to capture excess spring runoff and extreme rainfall events, reducing flood potential downstream. Additionally, retention ponds may be used for biomass production and nutrient retention. The purpose of this research was to investigate the economic viability of adopting local farm surface water retention systems as a strategic water management strategy. A retention pond was analyzed using a dynamic simulation model to predict its storage capacity, installation and upkeep cost, and economic advantage to farmers when used for irrigation. While irrigation application increased crop revenue, the cost of irrigation and reservoir infrastructure and installation costs were too high for the farmer to experience a positive net revenue. Farmers who harvest cattails from retention systems for biomass and available carbon offset credits can gain 642.70/hectare of harvestable cattail/year. Cattail harvest also removes phosphorus and nitrogen, providing a monetized impact of 7014/hectare of harvestable cattail/year. The removal of phosphorus, nitrogen, carbon, and avoided flooding damages of the retention basin itself provide an additional 17,730-18,470/hectare of retention system/year. The recommended use of retention systems is for avoided flood damages, nutrient retention, and biomass production. The revenue gained from these functions can support farmers wanting to invest in irrigation while providing economic and environmental benefits to the region.

Radon-hazard potential the Beaver basin, Utah

International Nuclear Information System (INIS)

Bishop, C.E.

1995-01-01

Indoor-radon levels in the Beaver basin of southwestern Utah are the highest recorded to date in Utah, ranging from 17.5 to 495 picocuries per liter (pCi/L). Because the U.S. Environment Protection Agency considers indoor-radon levels above 4 pCi/L to represent a risk of lung cancer from long-term exposure, the Utah Geological Survey is preparing a radon-hazard-potential map for the area to help prioritize indoor testing and evaluate the need for radon-resistant construction. Radon is a chemically inert radioactive gas derived from the decay of uranium-238, which is commonly found in rocks and soils. Soil permeability, depth to ground water, and uranium/thorium content of source materials control the mobility and concentration of radon in the soil. Once formed, radon diffuses into the pore space of the soil and then to the atmosphere or into buildings by pressure-driven flow of air or additional diffusion. The Beaver basin has been a topographic and structural depression since late Miocene time. Paleocene to Miocene volcanic and igneous rocks border the basin. Uraniferous alluvial-fan, piedmont-slope, flood-plain, and lacustrine sediments derived from the surrounding volcanic rocks fill the basin. A soil-gas radon and ground radioactivity survey in the Beaver basin shows that soils have high levels of radon gas. In this survey, uranium concentrations range from 3 to 13 parts per million (ppm) and thorium concentrations range from 10 to 48 ppm. Radon concentrations in the soil gas ranged from 85 to 3,500 pCi/L. The highest concentrations of uranium, thorium, and radon gas and the highest radon-hazard-potential are in the well-drained permeable soils in the lower flood- plain deposits that underlie the city of Beaver

Water quality of the Swatara Creek Basin, PA

Science.gov (United States)

McCarren, Edward F.; Wark, J.W.; George, J.R.

1964-01-01

The Swatara Creek of the Susquehanna River Basin is the farthest downstream sub-basin that drains acid water (pH of 4.5 or less) from anthracite coal mines. The Swatara Creek drainage area includes 567 square miles of parts of Schuylkill, Berks, Lebanon, and Dauphin Counties in Pennsylvania.To learn what environmental factors and dissolved constituents in water were influencing the quality of Swatara Creek, a reconnaissance of the basin was begun during the summer of 1958. Most of the surface streams and the wells adjacent to the principal tributaries of the Creek were sampled for chemical analysis. Effluents from aquifers underlying the basin were chemically analyzed because ground water is the basic source of supply to surface streams in the Swatara Creek basin. When there is little runoff during droughts, ground water has a dominating influence on the quality of surface water. Field tests showed that all ground water in the basin was non-acidic. However, several streams were acidic. Sources of acidity in these streams were traced to the overflow of impounded water in unworked coal mines.Acidic mine effluents and washings from coal breakers were detected downstream in Swatara Creek as far as Harper Tavern, although the pH at Harper Tavern infrequently went below 6.0. Suspended-sediment sampling at this location showed the mean daily concentration ranged from 2 to 500 ppm. The concentration of suspended sediment is influenced by runoff and land use, and at Harper Tavern it consisted of natural sediments and coal wastes. The average daily suspended-sediment discharge there during the period May 8 to September 30, 1959, was 109 tons per day, and the computed annual suspended-sediment load, 450 tons per square mile. Only moderate treatment would be required to restore the quality of Swatara Creek at Harper Tavern for many uses. Above Ravine, however, the quality of the Creek is generally acidic and, therefore, of limited usefulness to public supplies, industries and

Process for storing radioactive waste in ground

International Nuclear Information System (INIS)

Cohen, P.; Gouvenot, D.; Pagny, P.

1983-01-01

A process for storing radioactive waste in a cavity in the ground is claimed. The waste is conditioned and isolated from the ground by at least one retention barrier. A grout consisting of 1000 parts by weight of water, 40 to 400 parts by weight of cement, 80 to 1000 parts by weight of at least one clay chosen from the group including montmorillonite, illite and vermiculite, as well as 25 to 1200 parts by weight of kieselguhr and/or natural or artificial pozzuolanas is introduced into gaps in the soil areas surrounding the cavity

Enhancing retention of partial dentures using elastomeric retention rings

Directory of Open Access Journals (Sweden)

Kakkirala Revathi

2015-01-01

Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

Ground Improvement of Dune Sand Fields For The Purpose of Moisture Retention

OpenAIRE

Dr.A.S.Wayal; Dr.N.K.Ameta

2014-01-01

Plant growth depends on the use of two important natural resources, soil and water. Soil provides the mechanical and nutrient support necessary for plant growth. Water is the major input for the growth and development of all types of plants. The availability of water, its movement and its retention are governed by the properties of soil. The properties like bulk density, mechanical composition, hydraulic conductivity etc depends on the nature and formation of soil and land use...

Basin characterization and determination of hydraulic connectivity of mega basins using integrated methods: (The case of Baro-Akobo and mega watershed beyond)

Science.gov (United States)

Alemayehu, Taye; Kebede, Tesfaye; Liu, Lanbo

2018-01-01

Despite being the longest river and the fourth in drainage area, Nile River has the lowest discharge per unit areas among the top ten rivers of the world. Understanding the hydrologic significance of the regional litho-stratigraphy and structures help to better understand the hydrodynamics. This work is aimed at characterizing the Baro-Akobo-Sobbat sub-basin of Nile and determine trans-basin flows. Integrated method is used to characterize the basin and determine the Baro-Akobo-Sobbat sub-basin's relationship with African Mesozoic Rifts. Oil and water well drilling logs; aeromagnetic, gravity and vertical electrical sounding data; and various study reports are used to establish regional lithostratigraphic correlations and determine trans-regional hydrogeological connectivity. A total of 633 samples collected from wells, springs, rivers, lakes, swamps and rain water are analysed for their chemical, stable isotopes, tritium and radon properties. The Baro-Akobo river basin is commonly presumed to have good groundwater potential, particularly in its lowland plain. However, it has poor exploitable groundwater potential and recharge rate due to the extensive clay cover, limited retention capacity and the loss of the bulk of the groundwaters through regional geological structures to the deep seated continental sediments; presumably reaching the hydraulically connected African Mesozoic Rifts; mainly Melut and Muglad. The deep underground northward flows, along Nile River is, presumably, retarded by Central African Shear Zone in the Sudan.

Exploring Changes in Nitrogen and Phosphorus Retention in Global Rivers in the Twentieth Century

Science.gov (United States)

Beusen, A.; Bouwman, L.; Van Beek, R.; Wisser, D.; Hartmann, J.

2012-12-01

Nutrients are transported from land to sea through the continuum formed by components of river basins (soils, groundwater, riparian zones, streams, rivers, lakes, and reservoirs). The hydrology, ecology and biogeochemical processing in each of these components are strongly coupled and result in retention of a significant fraction of the nutrients transported. For analyzing the impact of multiple changes and disturbances at the global scale, we use a distributed approach to describe the nitrogen (N) and phosphorus (P) transport and retention in all the above river basin components. A hydrological model is used to describe the water flow through the respective compartments. We analyze the changes in retention during the past century (1900-2000), as this period encompasses dramatic increases in human population and economic human activities that have resulted in global changes, such as climate change, land use change, changes in the hydrology by dam construction, irrigation, and consumptive water use. In the period 1900-2000, the global soil N budget surplus (inputs minus withdrawal by plants) for agricultural and natural ecosystems increased from 118 to 202 Tg yr-1, and the global P budget increased from nutrient spiraling concept. We concentrate on the flows of total N and total P, because of the importance of the ratios between these two elements for biogeochemistry and the functioning of aquatic ecosystems. Since the various processes in the different compartments in terms of delivery to surface water are poorly known, we present a sensitivity analysis of the modeled river export for a number of key variables.

Finite Element Modelling of the Indo-Gangetic Basin to Study Site Amplification

Science.gov (United States)

Sivasubramonian, J.; Jaya, D.; Raghukanth, S. T. G.; Mai, P. M.

2017-12-01

We have developed a finite-element model of the 3D velocity structure of the Indo-Gangetic basin (IG basin) to quantify site amplifications due to seismic waves emanated from regional earthquakes. Estimating seismic wave amplifications is difficult in case of limited instrumentation, thus motivating us to propose a new simulation-based approach. The input required for the finite-element model include the spatial coordinates and the material properties (density, P-wave and S-wave velocities, Q factor) of the basin. Recent studies in the basin demarcate sediment layers of varying thickness, reaching down to a depth of 6 km and S-wave velocities ranging from 0.4-2.4 km/s (Srinivas et al., 2013). In the present study, our regional model has dimensions 900 x 900 x 80 km in x, y and z directions, discretized into 320 x 320 x 53 hexahedral elements. The top 6 km of the IG basin is divided into 8 different sediment layers with varying material properties. We use kinematic rupture models for the earthquake sources to simulate past as well as hypothetical future events. Two past earthquakes (Mw4.9, Delhi; Mw5.2, Chamoli) and two hypothetical earthquakes (Mw7.1; Mw8.5) are considered in our study. The rupture plane dimensions (L and W) and the slip distribution are estimated using the method of Mai and Beroza (2002). Based on focal-mechanism solutions and the depths of seismicity, we define the strike (580, 3090), the dip (650, 210), the rake (160, 770), and the depth of top edge of fault (5 km, 19 km) for the two large hypothetical earthquakes. Based on these parameters, the Centroid Moment Tensor (CMT) solution of the source is obtained. Ground motions are then simulated by solving the three-dimensional wave equation using the spectral element method (Komatitsch and Tromp, 1999). The key observations from our results are: 1) basin amplification factors for Peak Ground Velocity (PGV) are twice as high as Peak Ground Displacement (PGD) 2) PGV amplifications are as high as a

Use of Microgravity to Assess the Effects of El Nino on Ground-Water Storage in Southern Arizona

Science.gov (United States)

Parker, John T.C.; Pool, Donald R.

1998-01-01

The availability of ground water is of extreme importance in areas, such as southern Arizona, where it is the main supply for agricultural, industrial, or domestic purposes. Where ground-water use exceeds recharge, monitoring is critical for managing water supplies. Typically, monitoring has been done by measuring water levels in wells; however, this technique only partially describes ground-water conditions in a basin. A new application of geophysical technology is enabling U.S. Geological Survey (USGS) scientists to measure changes in the amount of water in an aquifer using a network of microgravity stations. This technique enables a direct measurement of ground-water depletion and recharge. In Tucson, Arizona, residents have relied solely upon ground water for most of their needs since the 19th century. Water levels in some wells in the Tucson area have declined more than 200 ft in the past 50 years. Similar drops in water levels have occurred elsewhere in Arizona. In response to the overdrafting of ground water, the State of Arizona passed legislation designed to attain 'safe yield,' which is defined as a balance between ground-water withdrawals and annual recharge of aquifers. To monitor progress in complying with the legislation, ground-water withdrawals are measured and estimated, and annual recharge is estimated. The Tucson Basin and Avra Valley are two ground-water basins that form the Tucson Active Management Area (TAMA), which by State statute must attain 'safe yield' by the year 2025.

Geology of photo linear elements, Great Divide Basin, Wyoming

Science.gov (United States)

Blackstone, D. L., Jr.

1973-01-01

The author has identified the following significant results. Ground examination of photo linear elements in the Great Divide Basin, Wyoming indicates little if any tectonic control. Aeolian aspects are more widespread and pervasive than previously considered.

Hydrogeology and water quality of the West Valley Creek Basin, Chester County, Pennsylvania

Science.gov (United States)

Senior, Lisa A.; Sloto, Ronald A.; Reif, Andrew G.

1997-01-01

The West Valley Creek Basin drains 20.9 square miles in the Piedmont Physiographic Province of southeastern Pennsylvania and is partly underlain by carbonate rocks that are highly productive aquifers. The basin is undergoing rapid urbanization that includes changes in land use and increases in demand for public water supply and wastewater disposal. Ground water is the sole source of supply in the basin.West Valley Creek flows southwest in a 1.5-mile-wide valley that is underlain by folded and faulted carbonate rocks and trends east-northeast, parallel to regional geologic structures. The valley is flanked by hills underlain by quartzite and gneiss to the north and by phyllite and schist to the south. Surface water and ground water flow from the hills toward the center of the valley. Ground water in the valley flows west-southwest parallel to the course of the stream. Seepage investigations identified losing reaches in the headwaters area where streams are underlain by carbonate rocks and gaining reaches downstream. Tributaries contribute about 75 percent of streamflow. The ground-water and surface-water divides do not coincide in the carbonate valley. The ground-water divide is about 0.5 miles west of the surface-water divide at the eastern edge of the carbonate valley. Underflow to the east is about 1.1 inches per year. Quarry dewatering operations at the western edge of the valley may act partly as an artificial basin boundary, preventing underflow to the west. Water budgets for 1990, a year of normal precipitation (45.8 inches), and 1991, a year of sub-normal precipitation (41.5 inches), were calculated. Streamflow was 14.61 inches in 1990 and 12.08 inches in 1991. Evapotranspiration was estimated to range from 50 to 60 percent of precipitation. Base flow was about 62 percent of streamflow in both years. Exportation by sewer systems was about 3 inches from the basin and, at times, equaled base flow during the dry autumn of 1991. Recharge was estimated to be 18

Seismicity of the Paradox Basin and the Colorado Plateau interior

International Nuclear Information System (INIS)

Wong, I.G.

1984-04-01

National Waste Terminal Storage Program site qualification criteria require that a nuclear waste repository be located so that ground motion associated with the maximum credible and maximum probable earthquakes or other earthquake-associated effects will not have an unacceptable adverse impact on system performance. To determine whether a potential repository site located in the Paradox salt formation in the Paradox Basin of southeastern Utah satisfies these criteria, seismological studies were undertaken by Woodward-Clyde Consultants (WCC) in March 1978. These studies included: (1) analysis of historical seismicity; (2) analysis of contemporary seismicity and tectonics of both the Paradox Basin and surrounding Colorado Plateau, including an extensive program of microearthquake monitoring; (3) evaluation of the Paradox Basin crustal structure; (4) evaluation of mining-induced seismicity; and (5) characterization of design-related earthquake-induced ground motions pertinent to a potential repository site through studies of attentation and subsurface ground motions. A detailed discussion of the results of the seismological studies performed through December 1980 is contained in WCC (1982). The purpose of this topical report is to update and summarize the studies on the local, regional, and mining-induced seismicity conducted through December 1982. The limitations of any interpretations are also discussed and additional information that remains to be acquired is identified. 56 references, 45 figures, 4 tables

Ground-water resources of the Sevier River basin between Yuba Dam and Leamington Canyon, Utah

Science.gov (United States)

Bjorklund, Louis Jay; Robinson, Gerald B.

1968-01-01

The area investigated is a segment of the Sevier River basin, Utah, comprising about 900 square miles and including a 19-mile reach of the Sevier River between Yuba Dam and Leamington Canyon. The larger valleys in the area are southern Juab, Round, and Scipio Valleys. The smaller valleys are Mills, Little, Dog, and Tinctic Wash Valleys.The geology of parts of Scipio, Little, and Mills Valleys and parts of the surrounding highlands was mapped and studied to explain the occurrence of numerous sinkholes in the thre valleys and to show their relation to the large springs in Mills Valley. The sinkholes, which are formed in the alluvium, are alined along faults, which penetrate both the alluvium and the underlying bedrock, and they have been formed by collapse of solution cavities in the underlying bedrock. The bedrock is mostly sandy limestone beds of the upper part of the North Horn Formation and of the Flagstaff Limestone. The numerous faults traversing Scipio Valley in a north-northeasterly direction trend directly toward Molter and Blue Springs in Mills Valley. One fault, which can be traced directly between the springs, probably is the principal channelway for the ground water moving from Scipio and Little Valleys to the springs.

Ground failure in the 2001 Mw 8.4 southern Peru earthquake

Science.gov (United States)

Rondinel-Oviedo, Efrain Alejandro

On June 23rd 2001 a moment magnitude (M W) 8.4, earthquake shook the southern portion of Peru. This rare large-magnitude event provided a unique opportunity to develop a suite of high quality case histories and also to test and calibrate existing geotechnical earthquake engineering analysis procedures and models against observations from the earthquake. The work presented in this thesis is focused on three topics pertaining to ground failure (i.e., the permanent deformation of the ground resulting from an earthquake) observed during the event: (1) surface ground damage in small basin geometries, (2) seismic compression, and (3) performance of a concrete faced rockfill dam (CFRD) dam. Surface ground strain damage patterns in small basin geometries has previously been typically studied at the large (i.e., geological) scale, but not at the scale of civil engineering infrastructure. During seismic events basin geometries containing soft material confined by stiffer material trap the seismic waves and generate surface waves that travel on the ground along the soft material. Numerical modeling shows that surface waves are generated at basin edges and travel on the ground creating higher duration, higher response (peak ground acceleration, PGA), higher energy (Arias Intensity) and higher angular distortion, especially in zones close to the edges. The impedance contrast between the stiff material and the soft material, and the dip angle play an important role in basin response. Seismic compression (i.e., the shaking induced densification of unsaturated soil) was observed in many highway embankments in the region of the earthquake. In many instances, this phenomenon was exasperated by soil-structure interaction with adjacent bridge or culvert structures. Numerical modeling conducted as part of this research showed (i) a significantly different response when the structure (culvert) is considered, (ii) impedance contrast plays a role in the system responses, and (iii) low

Ground water in selected areas in the Klamath Basin, Oregon

Science.gov (United States)

Leonard, A.R.; Harris, A.B.

1973-01-01

GROUNDWATER FEATURES OF SIX LOWLAND AREAS IN THE KLAMATH BASIN OF OREGON--KLAMATH MARSH AREA, AND SPRAGUE RIVER, SWAN LAKE, YONNA, POE, AND LANGELL VALLEYS--ARE DESCRIBED. RUGGED MOUNTAINS AND RIDGES SURROUND AND SEPARATE THESE LOWLANDS WHERE FLOORS RANGE IN ALTITUDE FROM 4,100 FEET IN POE VALLEY TO 4,600 FEET NORTH OF KLAMATH MARSH. THE SIX AREAS EXTEND OVER A NORTH-SOUTH DISTANCE OF 70 MILES, AN EAST-WEST DISTANCE OF 40 MILES, AND INCLUDE AN AREA OF APPROXIMATELY 600 SQUARE MILES. THE AREA IS SEMIARID AND RECEIVED ABOUT 14 TO 18 INCHES OF PRECIPITATION A YEAR. EXTINCT VOLCANOES AND THEIR EXTRUSIONS CHARACTERIZE THE AREA. MOST WELLS TAP PERMEABLE BASALT OR CINDERY RUBBLE BENEATH THE LACUSTRINE BEDS. THE DEPTHS OF WELLS RANGE FROM LESS THAN 50 TO NEARLY 2,000 FEET--MOST ARE BETWEEN 100 AND 1,000 FEET DEEP. FLOWING WELLS OCCUR IN ALL AREAS EXCEPT SWAN LAKE VALLEY. THE MOST EXTENSIVE AREA OF FLOWING WELLS IS IN THE SPRAGUE RIVER VALLEY, WHERE ABOUT 25 WELLS, SOME FLOWING MORE THAN 2,000 GPM, SUPPLY WATER FOR IRRIGATION. WATER LEVELS IN WELLS FLUCTUATE SEASONALLY FROM 1 TO 4 FEET. GROUNDWATER IN THE BASIN IS OF EXCELLENT QUALITY FOR DRINKING, IRRIGATION, AND MOST INDUSTRIAL USES.

Recent Climate Changes in Northwestern Qaidam Basin Inferred from Geothermal Gradients

Science.gov (United States)

Liu, J.; Zhang, T.

2014-12-01

Temperature perturbations under the ground surface are direct thermal response to ground surface temperature changes. Thus ground surface temperature history can be reconstructed from borehole temperature measurements using borehole paleothermometry inversion method. In this study, we use seven borehole temperature profiles to reconstruct the ground surface temperature variation of the past 500 years of the Qaidam basin, northwestern China. Borehole transient temperature measurement from seven sites in northwestern Qaidam basin were separated from geothermal gradients and analyzed by functional space inversion method to determine past ground surface temperature variations in this region. All temperature profiles show the effects of recent climatic disturbances. Inversion shows an overall increase in ground surface temperature by an averaged 1.2℃ (-0.11~2.21℃) during the last 500 years. Clear signs of a cold period between 1500 and 1900 A.D., corresponding to the Little Ice Age, have been found. Its coldest period was between 1780~1790 A.D. with the ground surface temperature of 5.4℃. During the 19th and the 20th century, reconstructed ground surface temperature shows a rising trend, and in the late 20th century, the temperature started to decrease. However, the highest temperature in 1990s broke the record of the past 500 years. This reconstructed past ground surface temperature variation is verified by the simulated annual surface air temperature computed by EdGCM and the cooling trend is also confirmed by other reconstruction of winter half year minimum temperatures using tree rings on the northeastern Tibetan Plateau.

Detection of induced seismicity effects on ground surface using data from Sentinel 1A/1B satellites

Science.gov (United States)

Milczarek, W.

2017-12-01

Induced seismicity is the result of human activity and manifests itself in the form of shock and vibration of the ground surface. One of the most common factors causing the occurrence of induced shocks is underground mining activity. Sufficiently strong high-energy shocks may cause displacements of the ground surface. This type of shocks can have a significant impact on buildings and infrastructure. Assessment of the size and influence of induced seismicity on the ground surface is one of the major problems associated with mining activity. In Poland (Central Eastern Europe) induced seismicity occurs in the area of hard coal mining in the Upper Silesian Coal Basin and in the area of the Legnica - Głogów Copper Basin.The study presents an assessment of the use of satellite radar data (SAR) for the detection influence of induced seismicity in mining regions. Selected induced shocks from the period 2015- 2017 which occurred in the Upper Silesian Coal Basin and the Legnica - Głogów Copper Basin areas have been analyzed. In the calculations SAR data from the Sentinel 1A and Sentinel 1B satellites have been used. The results indicate the possibility of quickly and accurate detection of ground surface displacements after an induced shock. The results of SAR data processing were compared with the results from geodetic measurements. It has been shown that SAR data can be used to detect ground surface displacements on the relative small regions.

Repository site data and information in bedded salt: Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Tien, P.; Nimick, F.B.; Muller, A.B.; Davis, P.A.; Guzowski, R.V.; Duda, L.E.; Hunter, R.L.

1983-11-01

This report is a compilation of data from the literature on the Palo Duro Basin. The Palo Duro Basin is a structural basin, about 150 miles long and 80 miles wide, that is a part of the much larger Permian Basin. The US Department of Energy is investigating the Palo Duro Basin as a potentially suitable area for the site of a repository for the disposal of high-level radioactive waste. Sediments overlying the Precambrian basement range from about 5000 to about 11,000 ft in thickness and from Cambrian to Holocene in age. The strata in the Palo Duro Basin that are of primary interest to the Department of Energy are the bedded salts of the Permian San Andres Formation. The total thickness of the bedded salts is about 2000 ft. The geology of the Palo Duro Basin is well understood. A great deal of information exists on the properties of salt, although much of the available information was not collected in the Palo Duro Basin. Mineral resources are not currently being exploited from the center of the Palo Duro Basin at depth, although the possibility of exploration for and development of such resources can not be ruled out. The continued existence of salts of Permian age indicates a lack of any large amount of circulating ground water. The hydrology of the pre-Tertiary rocks, however, is currently too poorly understood to carry out detailed, site-specific hydrologic modeling with a high degree of confidence. In general, ground water flows from west to east in the Basin. There is little or no hydraulic connection between aquifers above and below the salt sequences. Potable water is pumped from the Ogallala aquifer. Most of the other aquifers yield only nonpotable water. More extensive hydrological data are needed for detailed future modeling in support of risk assessment for a possible repository for high-level waste in the Palo Duro Basin. 464 references

Ground radiometric anomalies of the Serres Basin

International Nuclear Information System (INIS)

Kyrtsou, Christine.

1983-01-01

This work deals with the geology and radioactivity of a part of the Serres Basin which is made up by the Tertiary sedimentary sequence, peculiar toward the western edge of Rhodope, with lignites occurring locally. The area is transected by three northwesterly trending major faults having a throw of over 150 m. The purpose of this work was the location of as many as possible areas exhibiting a radioactivity much higher than the normal background, as well as their comparison and classification in orders of magnitude. The background radioactivity in the area varies between 150 to 200 c/s; deviations higher than this range area considered to be anomalous. An area of 75 km 2 has been explored where 170 sites exhibiting high radioactivity ranging from 2 to 20 times the background have been located; description of these areas appears in the tables. Of the 170 sites 100 refer to lignite bearing argillaceous sandstone formations, while the rest of them consists of altered sandstones, fossiliferous limestones and other sedimentary sequences. (N.Ch.)

Urban land use: Remote sensing of ground-basin permeability

Science.gov (United States)

Tinney, L. R.; Jensen, J. R.; Estes, J. E.

1975-01-01

A remote sensing analysis of the amount and type of permeable and impermeable surfaces overlying an urban recharge basin is discussed. An effective methodology for accurately generating this data as input to a safe yield study is detailed and compared to more conventional alternative approaches. The amount of area inventoried, approximately 10 sq. miles, should provide a reliable base against which automatic pattern recognition algorithms, currently under investigation for this task, can be evaluated. If successful, such approaches can significantly reduce the time and effort involved in obtaining permeability data, an important aspect of urban hydrology dynamics.

Hydrogeochemistry and isotopic study of ground and surface water in the Ayensu Basin of the Central Region

International Nuclear Information System (INIS)

Zakaria, N.

2010-01-01

The Central Region is a water stressed area. Some of the boreholes drilled by the people become salty and therefore resort to surface waters which are most of the time affected by water borne diseases. The main aim of the study is to understand the hydrogeochemical and isotopic hydrology of the Ayensu Basin. It mainly used hydrochemistry, environmental isotopes and Piper diagrams to obtain an understanding of the functioning of the system. 23 borehole samples, 2 samples from hand dug wells and 4 samples form the River Ayensu were taken from the Ayensu Basin. The samples were analyzed for physical parameters, major ions as well as trace elements using spectrophotometer, atomic absorption spectrophotometry (AAS) and Neutron activation analysis. The results showed that the groundwater in the study is fresh (TDS 75.2-804mg/l) and generally mildly acidic to neutral (pH 5.53-7.21). The ground water quality of the study area was good since most of the parameters measured were within the World Health Organisation (WHO) recommended values. However, a few, such as aluminium, manganese and iron showed elevated concentrations in most of the samples. The Piper trilinear diagram shows the major water types as mainly Na-Cl, Na-HC0 3 -Cl, Na-Cl-SO 4 and Na-Mg-Cl. A plot of δ 18 O versus δ 2 H showed the groundwaters clustering along the local meteoric water line indicating that groundwaters do not undergo significant evaporation before recharge. The trace element concentrations were found to be generally low with Al being the highest, followed by copper and manganese, cadmium was found to be below the detection limit of 0.001mg/l. Concentrations of Cr, Zn, and As were also very small. (au)

Water-quality assessment of the lower Illinois River Basin; environmental setting

Science.gov (United States)

Warner, Kelly L.

1998-01-01

The lower Illinois River Basin (LIRB) encompasses 18,000 square miles of central and western Illinois. Historical and recent information from Federal, State, and local agencies describing the physiography, population, land use, soils, climate, geology, streamflow, habitat, ground water, water use, and aquatic biology is summarized to describe the environmental setting of the LIRB. The LIRB is in the Till Plains Section of the Central Lowland physiographic province. The basin is characterized by flat topography, which is dissected by the Illinois River. The drainage pattern of the LIRB has been shaped by many bedrock and glacial geologic processes. Erosion prior to and during Pleistocene time created wide and deep bedrock valleys. The thickest deposits and most major aquifers are in buried bedrock valleys. The Wisconsinan glaciation, which bisects the northern half of the LIRB, affects the distribution and characteristics of glacial deposits in the basin. Agriculture is the largest land use and forested land is the second largest land use in the LIRB. The major urban areas are near Peoria, Springfield, Decatur, and Bloomington-Normal. Soil type and distribution affect the amount of soil erosion, which results in sedimentation of lakes and reservoirs in the basin. Rates of soil erosion of up to 2 percent per year of farmland soil have been measured. Many of the 300 reservoirs, lakes, and wetlands are disappearing because of sedimentation resulting from agriculture activities, levee building, and urbanization. Sedimentation and the destruction of habitat appreciably affect the ecosystem. The Illinois River is a large river-floodplain ecosystem where biological productivity is enhanced by annual flood pulses that advance and retreat over the flood plain and temporarily expand backwater and flood-plain lakes. Ground-water discharge to streams affects the flow and water quality of the streams. The water budget of several subbasins show variability in ground

Radionuclide Retention in Concrete Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

2010-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

Water equivalent of snow survey of the Red River Basin and Heart/Cannonball River Basin, March 1978

International Nuclear Information System (INIS)

Feimster, E.L.

1979-10-01

The water equivalent of accumulated snow was estimated in the Red River and Heart/Cannonball River basins and surrounding areas in North Dakota during the period 8 to 17 March 1978. A total of 570 km were flown, covering a 274 km section of the Red River Basin watershed. These lines had been surveyed in March 1974. Twelve flight lines were flown over the North Dakota side of the Red River from a point 23 km south of the Canadian border southward to the city of Fargo, North Dakota. The eight flight lines flown over the Minnesota side of the Red River extended from 23 km south of the Canadian border southward to Breckenridge, Minnesota. Using six flight lines, a total of 120 km were flown in the Heart/Cannonball River Basin, an area southwest of the city of Bismark, North Dakota. This was the first such flight in the Heart/Cannonball River Basin area. Computed weighted average water equivalents on each flight line in the Red River Basin ranged from 4.8 cm to 12.7 cm of water, averaging 7.6 cm for all lines. In the Heart/Cannonball River Basin, the weighted water equivalent ranged from 8.9 cm to 19.1 cm of water, averaging 12.7 cm for all lines. The method used employs the measurement of the natural gamma rays both before and after snow covers the ground

LERF Basin 44 Process Test Plan

International Nuclear Information System (INIS)

LUECK, K.J.

1999-01-01

This document presents a plan to process a portion of the Liquid Effluent Retention Facility (LERF) Basin 44 wastewater through the 200 Area Effluent Treatment Facility (ETF). The objective of this process test is to determine the most effective/efficient method to treat the wastewater currently stored in LERF Basin 44. The process test will determine the operational parameters necessary to comply with facility effluent discharge permit limits (Ecology 1995) and the Environmental Restoration Disposal Facility (ERDF) acceptance criteria (BHI-00139), while achieving ALARA goals and maintaining the integrity of facility equipment. A major focus of the test plan centers on control of contamination due to leaks and/or facility maintenance. As a pre-startup item, all known leaks will be fixed before the start of the test. During the course of the test, a variety of contamination control measures will be evaluated for implementation during the treatment of the remaining Basin 44 inventory. Of special interest will be techniques and tools used to prevent contamination spread during sampling and when opening contaminated facility equipment/piping. At the conclusion of the test, a post ALARA review will be performed to identify lessons learned from the test run which can be applied to the treatment of the remaining Basin 44 inventory. The volume of wastewater to be treated during this test run is 500,000 gallons. This volume limit is necessary to maintain the ETF radiological inventory limits per the approved authorization basis. The duration of the process test is approximately 30 days

Geohydrology and water utilization in the Willcox Basin, Graham and Cochise Counties, Arizona

Science.gov (United States)

Brown, S.G.; Schumann, Herbert H.

1969-01-01

moderately consolidated alluvium, undifferentiated, was only 7.4 gallons per minute per 100 feet of saturated material penetrated. The aquifer in the Kansas Settlement area is much less permeable but more homogeneous than the aquifer in the Stewart area. The coefficient of transmissibility of the aquifers, which was estimated from the specific-capacity data, ranged from 58,000 to 160,000 gal. tons per day per foot. Prior to extensive ground-water pumpage, the ground-water system probably was in equilibrium, with discharge equaling recharge. At that time, ground water moved toward the playa, where it was discharged by transpiration and evaporation. The estimate of the evapotranspiration in the playa area before large-scale development was about 75,000 acre-feet per year. On the basis of estimates of coefficients of transmissibility of the aquifer and on the basis of the water-table configuration, underflow toward the playa was computed to be about 54,000 acre-feet per year. By 1963, large-scale pumping had caused marked changes in the shape of the piezometric surface; large cones of depression had developed, and ground-water movement was toward the centers of pumping. The cones of depression caused by large-scale pumping have since expanded, and water-level declines have been measured in the recharge areas along the mountain fronts. Ground water has been used for irrigation since 1910. In 1928, about 4,000 acre-feet of ground water was pumped, and by 1963 180,000 acre-feet per year was being pumped. An estimated 1,860,000 acre-feet of water has been pumped for irrigation in the Willcox basin through 1963; 680,000 acre-feet from the Stewart area, 990,000 acre-feet from the Kansas Settlement area, and 190,000 acre-feet from the Pearce-Cochise area. In the Sierra Bonita Ranch area and the north playa area, ground-water withdrawal for irrigation through 1963 was small. From the spring of 1952 to the spring of 1964 water-level declines resulting from the

Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins.

Science.gov (United States)

O'Reilly, Andrew M; Wanielista, Martin P; Chang, Ni-Bin; Harris, Willie G; Xuan, Zhemin

2012-01-01

Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L and decreases in nitrate nitrogen (NO-N) from 2.7 mg L to soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0-7.8 mg L), resulting in NO-N of 1.3 to 3.3 mg L in shallow groundwater. Enrichment of δN and δO of NO combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO transport beneath the sandy basin. Soil-extractable NO-N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO impacts. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Relative Impacts of Low Permeability Subsurface Deposits on Recharge Basin Infiltration Rates

Science.gov (United States)

Oconnell, P.; Becker, M.; Pham, C.; Rodriguez, G.; Hutchinson, A.; Plumlee, M.

2017-12-01

Artificial recharge of aquifers through spreading basins has become an important component of water management in semi-arid climates. The rate at which water can be recharged in these basins is limited by the natural vertical permeability of the underlying deposits which may be highly variable both laterally and vertically. To help understand hydrostratigraphic controls on recharge, a newly constructed basin was surveyed and instrumented. Prior to flooding the basin, lithology was characterized by shallow hand coring, direct push coring, ground penetrating radar, and electrical resistivity. After flooding, recharge was monitored through piezometers, electrical resistivity, and a network of fiber optic distributed temperature sensing (DTS). The DTS network used temperature as a tracer to measure infiltration rate on 25 cm intervals both laterally and vertically. Several hundred paired DTS time series datasets (from fiber optic cables located at 0 and 0.5 meters below ground surface) were processed with the cross-wavelet transform (XWT) to calculate spatially and temporally continuous infiltration rates, which can be interpolated and animated to visualize heterogeneity. Time series data from 8-meter deep, vertically oriented DTS cables reveal depth intervals where infiltration rates vary. Inverted resistivity sections from repeated dipole-dipole surveys along the sidewall of a spreading basin exhibit a positive correlation with the distribution of relatively high and low infiltration rates, indicating zones of preferential downward (efficient) and lateral (inefficient) flow, respectively. In contrast to other monitored basins, no perching was observed in the vertically oriented DTS cables. The variation in recharge across the basin and the appearance of subsurface lateral flow can be explained in context of the alluvial depositional environment.

Congo Basin rainfall climatology: can we believe the climate models?

Science.gov (United States)

Washington, Richard; James, Rachel; Pearce, Helen; Pokam, Wilfried M; Moufouma-Okia, Wilfran

2013-01-01

The Congo Basin is one of three key convective regions on the planet which, during the transition seasons, dominates global tropical rainfall. There is little agreement as to the distribution and quantity of rainfall across the basin with datasets differing by an order of magnitude in some seasons. The location of maximum rainfall is in the far eastern sector of the basin in some datasets but the far western edge of the basin in others during March to May. There is no consistent pattern to this rainfall distribution in satellite or model datasets. Resolving these differences is difficult without ground-based data. Moisture flux nevertheless emerges as a useful variable with which to study these differences. Climate models with weak (strong) or even divergent moisture flux over the basin are dry (wet). The paper suggests an approach, via a targeted field campaign, for generating useful climate information with which to confront rainfall products and climate models.

Preliminary hydrologic budget studies, Indian Creek watershed and vicinity, Western Paradox Basin, Utah

International Nuclear Information System (INIS)

Thackston, J.W.; Mangarella, P.A.; Preslo, L.M.

1986-05-01

Preliminary quantitative estimates of ground-water discharge into the Colorado River System in the western Paradox Basin were prepared on the basis of existing climatological and streamflow records. Ground-water outflow to the river was deduced as a residual from hydrologic budget equations for two different study areas: (1) the region between gaging stations at Cisco, Green River, and Hite, Utah; and (2) the Indian Creek watershed. An empirical correlation between recharge rates and precipitation amounts derived for several basins in eastern Nevada was applied to estimate recharge amounts for the Indian Creek watershed. A simple Darcian flow model was then used to approximate the ground-water flux outward from the watershed for comparison. Salinity measurements in the Colorado River were also used to approximate ground-water outflow to a river reach in Cataract Canyon in order to provide another comparison with the hydrologic budget results. Although these estimates should be considered only gross approximations, all approaches used provide values of ground-water outflow that are much less than estimates of similar parameters provided by the US Geological Survey in recent hydrologic reconnaissance reports. Estimates contained herein will be refined in future numerical modeling and data collection studies

An Exploration of How Elementary School Principals Approach the Student Retention Decision Process

Science.gov (United States)

Martinez-Hicks, Laura M.

2012-01-01

This is a constructivist grounded theory study investigating how elementary principals approach the student retention decision process in their schools. Twenty-two elementary principals participated in the study using a selective or snowball sampling method. Principals worked in one of three districts in a mid-Atlantic state and had experience as…

Environmental Setting and Effects on Water Quality in the Great and Little Miami River Basins, Ohio and Indiana

Science.gov (United States)

Debrewer, Linda M.; Rowe, Gary L.; Reutter, David C.; Moore, Rhett C.; Hambrook, Julie A.; Baker, Nancy T.

2000-01-01

The Great and Little Miami River Basins drain approximately 7,354 square miles in southwestern Ohio and southeastern Indiana and are included in the more than 50 major river basins and aquifer systems selected for water-quality assessment as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Principal streams include the Great and Little Miami Rivers in Ohio and the Whitewater River in Indiana. The Great and Little Miami River Basins are almost entirely within the Till Plains section of the Central Lowland physiographic province and have a humid continental climate, characterized by well-defined summer and winter seasons. With the exception of a few areas near the Ohio River, Pleistocene glacial deposits, which are predominantly till, overlie lower Paleozoic limestone, dolomite, and shale bedrock. The principal aquifer is a complex buried-valley system of sand and gravel aquifers capable of supporting sustained well yields exceeding 1,000 gallons per min-ute. Designated by the U.S. Environmental Protection Agency as a sole-source aquifer, the Buried-Valley Aquifer System is the principal source of drinking water for 1.6 million people in the basins and is the dominant source of water for southwestern Ohio. Water use in the Great and Little Miami River Basins averaged 745 million gallons per day in 1995. Of this amount, 48 percent was supplied by surface water (including the Ohio River) and 52 percent was supplied by ground water. Land-use and waste-management practices influence the quality of water found in streams and aquifers in the Great and Little Miami River Basins. Land use is approximately 79 percent agriculture, 13 percent urban (residential, industrial, and commercial), and 7 percent forest. An estimated 2.8 million people live in the Great and Little Miami River Basins; major urban areas include Cincinnati and Dayton, Ohio. Fertilizers and pesticides associated with agricultural activity, discharges from municipal and

Nutrient removal using biosorption activated media: Preliminary biogeochemical assessment of an innovative stormwater infiltration basin

International Nuclear Information System (INIS)

O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.

2012-01-01

Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop an innovative stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO 3 − /Cl − ) ratios for the shallow groundwater indicates that prior to using BAM, NO 3 − concentrations were substantially influenced by nitrification or variations in NO 3 − input. In contrast, for the new basin utilizing BAM, NO 3 − /Cl − ratios indicate minor nitrification and NO 3 − losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest that NO 3 − losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by the increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO 4 3− ) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO 4 3− /Cl − ratios for shallow

Ambient Noise Green's Function Simulation of Long-Period Ground Motions for Reverse Faulting

Science.gov (United States)

Miyake, H.; Beroza, G. C.

2009-12-01

Long-time correlation of ambient seismic noise has been demonstrated as a useful tool for strong ground motion prediction [Prieto and Beroza, 2008]. An important advantage of ambient noise Green's functions is that they can be used for ground motion simulation without resorting to either complex 3-D velocity structure to develop theoretical Green’s functions, or aftershock records for empirical Green’s function analysis. The station-to-station approach inherent to ambient noise Green’s functions imposes some limits to its application, since they are band-limited, applied at the surface, and for a single force. We explore the applicability of this method to strong motion prediction using the 2007 Chuetsu-oki, Japan, earthquake (Mw 6.6, depth = 9 km), which excited long-period ground motions in and around the Kanto basin almost 200 km from the epicenter. We test the performance of ambient noise Green's function for long-period ground motion simulation. We use three components of F-net broadband data at KZK station, which is located near the source region, as a virtual source, and three components of six F-net stations in and around the Kanto basin to calculate the response. An advantage to applying this approach in Japan is that ambient-noise sources are active in diverse directions. The dominant period of the ambient noise for the F-net datasets is mostly 7 s over the year, and amplitudes are largest in winter. This period matches the dominant periods of the Kanto and Niigata basins. For the 9 components of the ambient noise Green’s functions, we have confirmed long-period components corresponding to Love wave and Rayleigh waves that can be used for simulation of the 2007 Chuetsu-oki earthquake. The relative amplitudes, phases, and durations of the ambient noise Green’s functions at the F-net stations in and around the Kanto basin respect to F-net KZK station are fairly well matched with those of the observed ground motions for the 2007 Chuetsu

Hydrological Cycle in the Heihe River Basin and Its Implication for Water Resource Management in Endorheic Basins

Science.gov (United States)

Li, Xin; Cheng, Guodong; Ge, Yingchun; Li, Hongyi; Han, Feng; Hu, Xiaoli; Tian, Wei; Tian, Yong; Pan, Xiaoduo; Nian, Yanyun; Zhang, Yanlin; Ran, Youhua; Zheng, Yi; Gao, Bing; Yang, Dawen; Zheng, Chunmiao; Wang, Xusheng; Liu, Shaomin; Cai, Ximing

2018-01-01

Endorheic basins around the world are suffering from water and ecosystem crisis. To pursue sustainable development, quantifying the hydrological cycle is fundamentally important. However, knowledge gaps exist in how climate change and human activities influence the hydrological cycle in endorheic basins. We used an integrated ecohydrological model, in combination with systematic observations, to analyze the hydrological cycle in the Heihe River Basin, a typical endorheic basin in arid region of China. The water budget was closed for different landscapes, river channel sections, and irrigation districts of the basin from 2001 to 2012. The results showed that climate warming, which has led to greater precipitation, snowmelt, glacier melt, and runoff, is a favorable factor in alleviating water scarcity. Human activities, including ecological water diversion, cropland expansion, and groundwater overexploitation, have both positive and negative effects. The natural oasis ecosystem has been restored considerably, but the overuse of water in midstream and the use of environmental flow for agriculture in downstream have exacerbated the water stress, resulting in unfavorable changes in surface-ground water interactions and raising concerns regarding how to fairly allocate water resources. Our results suggest that the water resource management in the region should be adjusted to adapt to a changing hydrological cycle, cropland area must be reduced, and the abstraction of groundwater must be controlled. To foster long-term benefits, water conflicts should be handled from a broad socioeconomic perspective. The findings can provide useful information on endorheic basins to policy makers and stakeholders around the world.

Recharge and Groundwater Flow Within an Intracratonic Basin, Midwestern United States.

Science.gov (United States)

Panno, Samuel V; Askari, Zohreh; Kelly, Walton R; Parris, Thomas M; Hackley, Keith C

2018-01-01

The conservative nature of chloride (Cl - ) in groundwater and the abundance of geochemical data from various sources (both published and unpublished) provided a means of developing, for the first time, a representation of the hydrogeology of the Illinois Basin on a basin-wide scale. The creation of Cl - isocons superimposed on plan view maps of selected formations and on cross sections across the Illinois Basin yielded a conceptual model on a basin-wide scale of recharge into, groundwater flow within and through the Illinois Basin. The maps and cross sections reveal the infiltration and movement of freshwater into the basin and dilution of brines within various geologic strata occurring at basin margins and along geologic structures. Cross-formational movement of brines is also seen in the northern part of the basin. The maps and cross sections also show barriers to groundwater movement created by aquitards resulting in areas of apparent isolation/stagnation of concentrated brines within the basin. The distribution of Cl - within the Illinois Basin suggests that the current chemical composition of groundwater and distribution of brines within the basin is dependent on five parameters: (1) presence of bedrock exposures along basin margins; (2) permeability of geologic strata and their distribution relative to one another; (3) presence or absence of major geologic structures; (4) intersection of major waterways with geologic structures, basin margins, and permeable bedrock exposures; and (5) isolation of brines within the basin due to aquitards, inhomogeneous permeability, and, in the case of the deepest part of the basin, brine density effects. © 2017, National Ground Water Association.

Geospatial data to support analysis of water-quality conditions in basin-fill aquifers in the southwestern United States

Science.gov (United States)

McKinney, Tim S.; Anning, David W.

2009-01-01

The Southwest Principal Aquifers study area consists of most of California and Nevada and parts of Utah, Arizona, New Mexico, and Colorado; it is about 409,000 square miles. The Basin-fill aquifers extend through about 201,000 square miles of the study area and are the primary source of water for cities and agricultural communities in basins in the arid and semiarid southwestern United States (Southwest). The demand on limited ground-water resources in areas in the southwestern United States has increased significantly. This increased demand underscores the importance of understanding factors that affect the water quality in basin-fill aquifers in the region, which are being studied through the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program. As a part of this study, spatial datasets of natural and anthropogenic factors that may affect ground-water quality of the basin-fill aquifers in the southwestern United States were developed. These data include physical characteristics of the region, such as geology, elevation, and precipitation, as well as anthropogenic factors, including population, land use, and water use. Spatial statistics for the alluvial basins in the Southwest have been calculated using the datasets. This information provides a foundation for the development of conceptual and statistical models that relate natural and anthropogenic factors to ground-water quality across the Southwest. A geographic information system (GIS) was used to determine and illustrate the spatial distribution of these basin-fill variables across the region. One hundred-meter resolution raster data layers that represent the spatial characteristics of the basins' boundaries, drainage areas, population densities, land use, and water use were developed for the entire Southwest.

Movement of water infiltrated from a recharge basin to wells.

Science.gov (United States)

O'Leary, David R; Izbicki, John A; Moran, Jean E; Meeth, Tanya; Nakagawa, Brandon; Metzger, Loren; Bonds, Chris; Singleton, Michael J

2012-01-01

Local surface water and stormflow were infiltrated intermittently from a 40-ha basin between September 2003 and September 2007 to determine the feasibility of recharging alluvial aquifers pumped for public supply, near Stockton, California. Infiltration of water produced a pressure response that propagated through unconsolidated alluvial-fan deposits to 125 m below land surface (bls) in 5 d and through deeper, more consolidated alluvial deposits to 194 m bls in 25 d, resulting in increased water levels in nearby monitoring wells. The top of the saturated zone near the basin fluctuates seasonally from depths of about 15 to 20 m. Since the start of recharge, water infiltrated from the basin has reached depths as great as 165 m bls. On the basis of sulfur hexafluoride tracer test data, basin water moved downward through the saturated alluvial deposits until reaching more permeable zones about 110 m bls. Once reaching these permeable zones, water moved rapidly to nearby pumping wells at rates as high as 13 m/d. Flow to wells through highly permeable material was confirmed on the basis of flowmeter logging, and simulated numerically using a two-dimensional radial groundwater flow model. Arsenic concentrations increased slightly as a result of recharge from 2 to 6 µg/L immediately below the basin. Although few water-quality issues were identified during sample collection, high groundwater velocities and short travel times to nearby wells may have implications for groundwater management at this and at other sites in heterogeneous alluvial aquifers. Ground Water © 2011, National Ground Water Association. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

Transient electromagnetic study of basin fill sediments in the Upper San Pedro Basin, Mexico

Science.gov (United States)

Bultman, M.W.; Gray, F.

2011-01-01

The Upper San Pedro River Basin in Mexico and the United States is an important riparian corridor that is coming under increasing pressure from growing populations and the associated increase in groundwater withdrawal. Several studies have produced three-dimensional maps of the basin fill sediments in the US portion of the basin but little work has been done in the Mexican portion of the basin. Here, the results of a ground-based transient electromagnetic (TEM) survey in the Upper San Pedro Basin, Mexico are presented. These basin fill sediments are characterized by a 10-40 m deep unsaturated surficial zone which is composed primarily of sands and gravels. In the central portion of the basin this unsaturated zone is usually underlain by a shallow clay layer 20-50 m thick. Beneath this may be more clay, as is usually the case near the San Pedro River, or interbedded sand, silt, and clay to a depth of 200-250 m. As you move away from the river, the upper clay layer disappears and the amount of sand in the sediments increases. At 1-2 km away from the river, sands can occupy up to 50% of the upper 200-250 m of the sediment fill. Below this, clays are always present except where bedrock highs are observed. This lower clay layer begins at a depth of about 200 m in the central portion of the basin (250 m or more at distances greater than 1-2 km from the river) and extends to the bottom of most profiles to depths of 400 m. While the depth of the top of this lower clay layer is probably accurate, its thickness observed in the models may be overestimated due to the relatively low magnetic moment of the TEM system used in this study. The inversion routine used for interpretation is based on a one-dimensional geologic model. This is a layer based model that is isotropic in both the x and y directions. Several survey soundings did not meet this requirement which invalidates the inversion process and the resulting interpretation at these locations. The results from these

Hybrid Genetic Algorithm - Local Search Method for Ground-Water Management

Science.gov (United States)

Chiu, Y.; Nishikawa, T.; Martin, P.

2008-12-01

Ground-water management problems commonly are formulated as a mixed-integer, non-linear programming problem (MINLP). Relying only on conventional gradient-search methods to solve the management problem is computationally fast; however, the methods may become trapped in a local optimum. Global-optimization schemes can identify the global optimum, but the convergence is very slow when the optimal solution approaches the global optimum. In this study, we developed a hybrid optimization scheme, which includes a genetic algorithm and a gradient-search method, to solve the MINLP. The genetic algorithm identifies a near- optimal solution, and the gradient search uses the near optimum to identify the global optimum. Our methodology is applied to a conjunctive-use project in the Warren ground-water basin, California. Hi- Desert Water District (HDWD), the primary water-manager in the basin, plans to construct a wastewater treatment plant to reduce future septic-tank effluent from reaching the ground-water system. The treated wastewater instead will recharge the ground-water basin via percolation ponds as part of a larger conjunctive-use strategy, subject to State regulations (e.g. minimum distances and travel times). HDWD wishes to identify the least-cost conjunctive-use strategies that control ground-water levels, meet regulations, and identify new production-well locations. As formulated, the MINLP objective is to minimize water-delivery costs subject to constraints including pump capacities, available recharge water, water-supply demand, water-level constraints, and potential new-well locations. The methodology was demonstrated by an enumerative search of the entire feasible solution and comparing the optimum solution with results from the branch-and-bound algorithm. The results also indicate that the hybrid method identifies the global optimum within an affordable computation time. Sensitivity analyses, which include testing different recharge-rate scenarios, pond

Desert basins of the Southwest

Science.gov (United States)

Leake, Stanley A.; Konieczki, Alice D.; Rees, Julie A.H.

2000-01-01

Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

Ground motion modeling of the 1906 San Francisco earthquake II: Ground motion estimates for the 1906 earthquake and scenario events

Energy Technology Data Exchange (ETDEWEB)

Aagaard, B; Brocher, T; Dreger, D; Frankel, A; Graves, R; Harmsen, S; Hartzell, S; Larsen, S; McCandless, K; Nilsson, S; Petersson, N A; Rodgers, A; Sjogreen, B; Tkalcic, H; Zoback, M L

2007-02-09

We estimate the ground motions produced by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

Distributed Modelling of Stormflow Generation: Assessing the Effect of Ground Cover

Science.gov (United States)

Jarihani, B.; Sidle, R. C.; Roth, C. H.; Bartley, R.; Wilkinson, S. N.

2017-12-01

Understanding the effects of grazing management and land cover changes on surface hydrology is important for water resources and land management. A distributed hydrological modelling platform, wflow, (that was developed as part of Deltares's OpenStreams project) is used to assess the effect of land management practices on runoff generation processes. The model was applied to Weany Creek, a small catchment (13.6 km2) of the Burdekin Basin, North Australia, which is being studied to understand sources of sediment and nutrients to the Great Barrier Reef. Satellite and drone-based ground cover data, high resolution topography from LiDAR, soil properties, and distributed rainfall data were used to parameterise the model. Wflow was used to predict total runoff, peak runoff, time of rise, and lag time for several events of varying magnitudes and antecedent moisture conditions. A nested approach was employed to calibrate the model by using recorded flow hydrographs at three scales: (1) a hillslope sub-catchment: (2) a gullied sub-catchment; and the 13.6 km2 catchment outlet. Model performance was evaluated by comparing observed and predicted stormflow hydrograph attributes using the Nash Sutcliffe efficiency metric. By using a nested approach, spatiotemporal patterns of overland flow occurrence across the catchment can also be evaluated. The results show that a process-based distributed model can be calibrated to simulate spatial and temporal patterns of runoff generation processes, to help identify dominant processes which may be addressed by land management to improve rainfall retention. The model will be used to assess the effects of ground cover changes due to management practices in grazed lands on storm runoff.

Numerical simulation of ground-water flow through glacial deposits and crystalline bedrock in the Mirror Lake area, Grafton County, New Hampshire

Science.gov (United States)

Tiedeman, Claire; Goode, Daniel J.; Hsieh, Paul A.

1997-01-01

recharge from precipitation to the water table is 26 to 28 cm/year. Hydraulic conductivities are 1.7 x 10-6 to 2.7 x 10-6 m/s for glacial deposits, about 3 x 10-7 m/s for bedrock beneath lower hillsides and valleys, and about 6x10-8 m/s for bedrock beneath upper hillsides and hilltops. Analysis of parameter uncertainty indicates that the above values are well constrained, at least within the context of regression analysis. In the regression, several attributes of the ground-water flow model are assumed perfectly known. The hydraulic conductivity for bedrock beneath upper hillsides and hilltops was determined from few data, and additional data are needed to further confirm this result. Model fit was not improved by introducing a 10-to-1 ration of horizontal-to-vertical anisotropy in the hydraulic conductivity of the glacial deposits, or by varying hydraulic conductivity with depth in the modeled part (uppermost 150m) of the bedrock. The calibrated model was used to delineate the Mirror Lake ground-water basin, defined as the volumes of subsurface through which ground water flows from the water table to Mirror Lake or its inlet streams. Results indicate that Mirror Lake and its inlet streams drain an area of ground-water recharge that is about 1.5 times the area of the surface-water basin. The ground-water basin extends far up the hillside on the northwestern part of the study area. Ground water from this area flows at depth under Norris Brook to discharge into Mirror Lake or its inlet streams. As a result, the Mirror Lake ground-water basin extends beneath the adjacent ground-water basin that drains into Norris Brook. Model simulation indicates that approximately 300,000 m3/year of precipitation recharges the Mirror Lake ground-water basin. About half the recharge enters the basin in areas where the simulated water table lies in glacial deposits; the other half enters the basin in areas where the simulated water table lies in be

Retention of heavy metals and poly-aromatic hydrocarbons from road water in a constructed wetland and the effect of de-icing

KAUST Repository

Tromp, Karin

2012-02-01

A full-scale remediation facility including a detention basin and a wetland was tested for retention of heavy metals and Poly-Aromatic Hydrocarbons (PAHs) from water drained from a motorway in The Netherlands. The facility consisted of a detention basin, a vertical-flow reed bed and a final groundwater infiltration bed. Water samples were taken of road water, detention basin influent and wetland effluent. By using automated sampling, we were able to obtain reliable concentration averages per 4-week period during 18 months. The system retained the PAHs very well, with retention efficiencies of 90-95%. While environmental standards for these substances were surpassed in the road water, this was never the case after passage through the system. For the metals the situation was more complicated. All metals studied (Cu, Zn, Pb, Cd and Ni) had concentrations frequently surpassing environmental standards in the road water. After passage through the system, most metal concentrations were lower than the standards, except for Cu and Zn. There was a dramatic effect of de-icing salts on the concentrations of Cu, Zn, Cd and Ni, in the effluent leaving the system. For Cu, the concentrations even became higher than they had ever been in the road water. It is advised to let the road water bypass the facility during de-icing periods. © 2011 Elsevier B.V.

Radioactive liquid wastes discharged to ground in the 200 areas during 1974

International Nuclear Information System (INIS)

Anderson, J.D.

1975-01-01

Radioactive liquid wastes discharged to ground during 1974 and since startup within the Production and Waste Management control zone are summarized in tabular form. Estimates of the radioactivity discharged to individual ponds, cribs, and retention sites are also summarized. (LK)

Estimating Natural Recharge in a Desert Environment Facing Increasing Ground-Water Demands

Science.gov (United States)

Nishikawa, T.; Izbicki, J. A.; Hevesi, J. A.; Martin, P.

2004-12-01

Ground water historically has been the sole source of water supply for the community of Joshua Tree in the Joshua Tree ground-water subbasin of the Morongo ground-water basin in the southern Mojave Desert. Joshua Basin Water District (JBWD) supplies water to the community from the underlying Joshua Tree ground-water subbasin, and ground-water withdrawals averaging about 960 acre-ft/yr have resulted in as much as 35 ft of drawdown. As growth continues in the desert, ground-water resources may need to be supplemented using imported water. To help meet future demands, JBWD plans to construct production wells in the adjacent Copper Mountain ground-water subbasin. To manage the ground-water resources and to identify future mitigating measures, a thorough understanding of the ground-water system is needed. To this end, field and numerical techniques were applied to determine the distribution and quantity of natural recharge. Field techniques included the installation of instrumented boreholes in selected washes and at a nearby control site. Numerical techniques included the use of a distributed-parameter watershed model and a ground-water flow model. The results from the field techniques indicated that as much as 70 acre-ft/yr of water infiltrated downward through the two principal washes during the study period (2001-3). The results from the watershed model indicated that the average annual recharge in the ground-water subbasins is about 160 acre-ft/yr. The results from the calibrated ground-water flow model indicated that the average annual recharge for the same area is about 125 acre-ft/yr. Although the field and numerical techniques were applied to different scales (local vs. large), all indicate that natural recharge in the Joshua Tree area is very limited; therefore, careful management of the limited ground-water resources is needed. Moreover, the calibrated model can now be used to estimate the effects of different water-management strategies on the ground

Ground-motion modeling of the 1906 San Francisco Earthquake, part II: Ground-motion estimates for the 1906 earthquake and scenario events

Science.gov (United States)

Aagaard, Brad T.; Brocher, T.M.; Dolenc, D.; Dreger, D.; Graves, R.W.; Harmsen, S.; Hartzell, S.; Larsen, S.; McCandless, K.; Nilsson, S.; Petersson, N.A.; Rodgers, A.; Sjogreen, B.; Zoback, M.L.

2008-01-01

We estimate the ground motions produce by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

Evaluation of the toxicological properties of ground- and surface-water samples from the Aral Sea Basin

International Nuclear Information System (INIS)

Bosch, K.; Erdinger, L.; Ingel, F.; Khussainova, S.; Utegenova, E.; Bresgen, N.; Eckl, P.M.

2007-01-01

In order to determine whether there is a potential health risk associated with the water supply in the Aral Sea Basin, ground- and surface-water samples were collected in and around Aralsk and from the Aral Sea in 2002. Water samples from Akchi, a small town close to Almaty, served as controls. Bioassays with different toxicological endpoints were employed to assess the general toxicological status. Additionally, the samples were analysed for microbial contamination. The samples were tested in the primary hepatocyte assay for their potential to induce micronuclei and chromosomal aberrations as cumulative indicators for genotoxicity. In parallel, the effects on cell proliferation evidenced by mitotic index and cytotoxicity such as the appearance of necrotic and apoptotic cells, were determined. Furthermore, samples were examined using the Microtox assay for general toxicity. Chemical analysis according to European regulations was performed and soil and water samples were analysed for DDT and DDE. The results obtained indicated no increased cyto- or genotoxic potential of the water samples, nor levels of DDT or DDE exceeding the thresholds levels suggested by WHO. Our data therefore do not support the hypothesis that the contamination of the drinking water in and around Aralsk is responsible for the health effects previously described such as increased rates of liver disease and in particular liver cancer. Microbiological analysis, however, revealed the presence of contamination in most samples analysed

The Italian Project S2 - Task 4:Near-fault earthquake ground motion simulation in the Sulmona alluvial basin

Science.gov (United States)

Stupazzini, M.; Smerzini, C.; Cauzzi, C.; Faccioli, E.; Galadini, F.; Gori, S.

2009-04-01

Recently the Italian Department of Civil Protection (DPC), in cooperation with Istituto Nazionale di Geofisica e Vulcanologia (INGV) has promoted the 'S2' research project (http://nuovoprogettoesse2.stru.polimi.it/) aimed at the design, testing and application of an open-source code for seismic hazard assessment (SHA). The tool envisaged will likely differ in several important respects from an existing international initiative (Open SHA, Field et al., 2003). In particular, while "the OpenSHA collaboration model envisions scientists developing their own attenuation relationships and earthquake rupture forecasts, which they will deploy and maintain in their own systems", the main purpose of S2 project is to provide a flexible computational tool for SHA, primarily suited for the needs of DPC, which not necessarily are scientific needs. Within S2, a crucial issue is to make alternative approaches available to quantify the ground motion, with emphasis on the near field region. The SHA architecture envisaged will allow for the use of ground motion descriptions other than those yielded by empirical attenuation equations, for instance user generated motions provided by deterministic source and wave propagation simulations. In this contribution, after a brief presentation of Project S2, we intend to illustrate some preliminary 3D scenario simulations performed in the alluvial basin of Sulmona (Central Italy), as an example of the type of descriptions that can be handled in the future SHA architecture. In detail, we selected some seismogenic sources (from the DISS database), believed to be responsible for a number of destructive historical earthquakes, and derive from them a family of simplified geometrical and mechanical source models spanning across a reasonable range of parameters, so that the extent of the main uncertainties can be covered. Then, purely deterministic (for frequencies Journal of Seismology, 1, 237-251. Field, E.H., T.H. Jordan, and C.A. Cornell (2003

Nutrients and sediment in frozen-ground runoff from no-till fields receiving liquid-dairy and solid-beef manures

Science.gov (United States)

Komiskey, Matthew J.; Stuntebeck, Todd D.; Frame, Dennis R.; Madison, Fred W.

2011-01-01

Nutrients and sediment in surface runoff from frozen agricultural fields were monitored within three small (16.0 ha [39.5 ac] or less), adjacent basins at a no-till farm in southwest Wisconsin during four winters from 2003 to 2004 through 2006 to 2007. Runoff depths and flow-weighted constituent concentrations were compared to determine the impacts of surface-applied liquid-dairy or solid-beef manure to frozen and/or snow-covered ground. Despite varying the manure type and the rate and timing of applications, runoff depths were not significantly different among basins within each winter period. Sediment losses were low (generally less than 22 kg ha−1 [20 lb ac−1] in any year) and any statistical differences in sediment concentrations among basins were not related to the presence or absence of manure or the amount of runoff. Concentrations and losses of total nitrogen and total phosphorus were significantly increased in basins that had either manure type applied less than one week preceding runoff. These increases occurred despite relatively low application rates. Lower concentrations and losses were measured in basins that had manure applied in fall and early winter and an extended period of time (months) had elapsed before the first runoff event. The highest mean, flow-weighted concentrations of total nitrogen (31.8 mg L−1) and total phosphorus (10.9 mg L−1) occurred in winter 2003 to 2004, when liquid-dairy manure was applied less than one week before runoff. On average, dissolved phosphorus accounted for over 80% of all phosphorus measured in runoff during frozen-ground periods. The data collected as part of this study add to the limited information on the quantity and quality of frozen-ground runoff at field edges, and the results highlight the importance of manure management decisions during frozen-ground periods to minimize nutrients lost in surface runoff.

Nitrate retention in a sand plains stream and the importance of groundwater discharge

Science.gov (United States)

Robert S. Stelzer; Damion R. Drover; Susan L. Eggert; Maureen A. Muldoon

2011-01-01

We measured net nitrate retention by mass balance in a 700-m upwelling reach of a third-order sand plains stream, Emmons Creek, from January 2007 to November 2008. Surface water and ground-water fluxes of nitrate were determined from continuous records of discharge and from nitrate concentrations based on weekly and biweekly sampling at three surface water stations and...

Testing the larval drift hypothesis in the Baltic Sea: retention versus dispersion caused by wind-driven circulation

DEFF Research Database (Denmark)

Hinrichsen, H.H.; St. John, Michael; Aro, E.

2001-01-01

Retention or dispersion of larvae from the spawning grounds has been identified as one of the key processes influencing recruitment success in fish stocks. To examine the potential effects of transport on recruitment. numerical simulations were performed utilizing a three-dimensional physical oce...

Particle-tracking investigation of the retention of sucker larvae emerging from spawning grounds in Upper Klamath Lake, Oregon

Science.gov (United States)

Wood, Tamara M.; Wherry, Susan A.; Simon, David C.; Markle, Douglas F.

2014-01-01

This study had two objectives: (1) to use the results of an individual-based particle-tracking model of larval sucker dispersal through the Williamson River delta and Upper Klamath Lake, Oregon, to interpret field data collected throughout Upper Klamath and Agency Lakes, and (2) to use the model to investigate the retention of sucker larvae in the system as a function of Williamson River flow, wind, and lake elevation. This is a follow-up study to work reported in Wood and others (2014) in which the hydrodynamic model of Upper Klamath Lake was combined with an individual-based, particle-tracking model of larval fish entering the lake from spawning areas in the Williamson River. In the previous study, the performance of the model was evaluated through comparison with field data comprising larval sucker distribution collected in 2009 by The Nature Conservancy, Oregon State University (OSU), and the U.S. Geological Survey, primarily from the (at that time) recently reconnected Williamson River Delta and along the eastern shoreline of Upper Klamath Lake, surrounding the old river mouth. The previous study demonstrated that the validation of the model with field data was moderately successful and that the model was useful for describing the broad patterns of larval dispersal from the river, at least in the areas surrounding the river channel immediately downstream of the spawning areas and along the shoreline where larvae enter the lake. In this study, field data collected by OSU throughout the main body of Upper Klamath Lake, and not just around the Williamson River Delta, were compared to model simulation results. Because the field data were collected throughout the lake, it was necessary to include in the simulations larvae spawned at eastern shoreline springs that were not included in the earlier studies. A complicating factor was that the OSU collected data throughout the main body of the lake in 2011 and 2012, after the end of several years of larval drift

Ground-water availability in the central part of Lake Ontario basin, New York

Science.gov (United States)

Miller, Todd S.; Krebs, Martha M.

1988-01-01

A set of three maps showing surficial geology, distribution of glacial aquifers, and potential well yield in the 708 sq mi central part of the Lake Ontario basin are presented at a scale of 1:125,000. The basin is parallel to Lake Ontario and extends from Rochester in the west to Oswego in the east. Aquifers consisting primarily of sand and gravel formed where meltwaters from glaciers deposited kame and outwash sand and gravel and where wave action along shores of glacial lakes eroded, reworked , and deposited beaches. Thick deposits of well-sorted sand and gravel yield relatively large quantities of water - typically more than 100 gal/min. Aquifers consisting of thin beds of sand and (or) gravel or thick gravel that contain a large proportion of silt and fine sand yield moderate amounts of water, 10 to 100 gal/min. Dug and driven wells that tap fine to medium sand deposits typically yield 1 to 10 gal/min. (USGS)

Ground-water quality and geochemistry in Dayton, Stagecoach, and Churchill Valleys, western Nevada

Science.gov (United States)

Thomas, James M.; Lawrence, Stephen J.

1994-01-01

The U.S. Geological Survey investigated the quality of ground water in the Dayton, Stagecoach, and Churchill Valleys as part of the Carson River Basin National Water-Quality Assessment (NAWQA) pilot study. Four aquifer systems have been de- lineated in the study area. Principal aquifers are unconsolidated deposits at altitudes of less than 4,900 feet above sea level and more than 50 feet below land surface. Shallow aquifers are at altitudes of less than 4,900 feet and less than 50 feet below land surface. Upland aquifers are above 4,900 feet and provide recharge to the principal aquifers. Thermal aquifers, defined as those having a water temperature greater than 30 degrees Celsius, are also present. Ground water used in Dayton, Stagecoach, and Churchill Valleys is pumped from principal aquifers in unconsolidated basin-fill deposits. Ground water in these aquifers originates as precipitation in the adjacent mountains and is recharged by the Carson River and by underflow from adjacent upstream valleys. Ground-water flow is generally parallel to the direction of surface-water flow in the Carson River. Ground water is discharged by pumping, evapo- transpiration, and underflow into the Carson River. The results of geochemical modeling indicate that as ground water moves from upland aquifers in mountainous recharge areas to principal aquifers in basin-fill deposits, the following processes probably occur: (1) plagioclase feldspar, sodium chloride, gypsum (or pyrite), potassium feldspar, and biotite dissolve; (2) calcite precipitates; (3) kaolinite forms; (4) small amounts of calcium and magnesium in the water exchange for potassium on aquifer minerals; and (5) carbon dioxide is gained or lost. The geochemical models are consistent with (1) phases identified in basin- fill sediments; (2) chemical activity of major cations and silica; (3) saturation indices of calcite and amorphous silica; (4) phase relations for aluminosilicate minerals indicated by activity diagrams; and

Technical basis for high-level waste repository land control requirements for Palo Duro Basin, Paradox Basin, and Richton Dome

International Nuclear Information System (INIS)

Chen, C.P.; Raines, G.E.

1987-02-01

Three sites, the Palo Duro Basin in Texas, the Paradox Basin in Utah, and the Richton Dome in Mississippi, are being investigated by the US Department of Energy for high-level radioactive-waste disposal in mined, deep geologic repositories in salt. This report delineates the use of regulatory, engineering, and performance assessment information to establish the technical basis for controlled area requirements. Based on the size of the controlled area determined, plus that of the geologic repository operations area, recommendations of possible land control or ownership area requirements for each locale are provided. On a technical basis, the following minimum land control or ownership requirements are recommended, assuming repository operations area of 2240 ac (907 ha), or 3.5 mi 2 (9.1 km 2 ): Palo Duro Basin - 4060 ac (1643 ha), or 6.3 mi 2 (16.4 km 2 ); Paradox Basin - 4060 ac (1643 ha), or 6.3 mi 2 (16.4 km 2 ); and Richton Dome - 5000 ac (2024 ha), or 7.8 mi 2 (20.2 km 2 ). Of the factors used to determine the technically based recommendations, one was found to dominate each locale. For the Palo Duro and Paradox Basins, the dominant factor was the need to limit potential radionuclide release by ground-water flow to the accessible environment. For the Richton Dome, the dominant factor was the need to limit the potential effects of solution mining on dome and repository integrity

Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

Science.gov (United States)

Belcher, Wayne R.

2004-01-01

provided by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional ground-water flow system. Ground-water flow in the Death Valley region is composed of several interconnected, complex ground-water flow systems. Ground-water flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional ground-water flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and evapotranspiration (ET) are the dominant natural ground-water discharge processes. Ground water also is withdrawn for agricultural, commercial, and domestic uses. Ground-water flow in the DVRFS was simulated using MODFLOW-2000, a 3D finite-difference modular ground-water flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 m on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins, also simulated by drains. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient model gener

Modeling effects of secondary tidal basins on estuarine morphodynamics

Science.gov (United States)

Nnafie, Abdel; Van Oyen, Tomas; De Maerschalck, Bart

2017-04-01

Many estuaries are situated in very densely populated areas with high economic activities that often conflict with their ecological values. For centuries, geometry and bathymetry of estuaries have been drastically modified trough engineering works such as embanking, sand extraction, channel deepening, land reclamations, etc. It is generally recognized that these works may increase the tidal range (e.g., Scheldt, Ems, Elbe) and turbidity (e.g., Loire, Ems) in estuaries [cf. Kerner, 2007; Wang et al., 2009; Winterwerp and Wang, 2013; Van Maren et al., 2015b,a]. In recent years, construction of secondary basins (also called retention basins) has gained increasing popularity among coastal managers to reduce tidal range and turbidity [Donner et al., 2012]. Previous studies have shown that location, geometry and number of secondary basins have a significant impact on tidal characteristics and sediment transport [Alebregtse and de Swart, 2014; Roos and Schuttelaars, 2015]. However, knowledge on how these secondary basins affect the morphodynamic development of estuaries on long time scales (order decades to centuries) is still lacking. The specific objectives of this study are twofold. First, to investigate effects of secondary basins on the long-term morphodynamic evolution of estuaries. In particular, effects of the presence of such a basin on the morphodynamic evolution of the main channel in the estuary and the physics underlying channel migration will be examined. For this, the Western Scheldt estuary (situated in the Netherlands) is used as a case study, which used to consist of multiple secondary tidal basins that were located at different positions in the estuary, and which have been gradually closed off between 1800 and 1968. Second, to systematically quantify sensitivity of model results to location, geometry, and to number of secondary basins. To this end, the state-of-the- art numerical model Delft3D is used, which has been successfully applied to

Ground Water Recharge Estimation Using Water Table Fluctuation Method And By GIS Applications

Science.gov (United States)

Vajja, V.; Bekkam, V.; Nune, R.; M. v. S, R.

2007-05-01

Quite often it has become a debating point that how much recharge is occurring to the groundwater table through rainfall on one hand and through recharge structures such as percolation ponds and checkdams on the other. In the present investigations Musi basin of Andhra Pradesh, India is selected for study during the period 2005-06. Pre-monsoon and Post-monsoon groundwater levels are collected through out the Musi basin at 89 locations covering an area11, 291.69 km2. Geology of the study area and rainfall data during the study period has been collected. The contour maps of rainfall and the change in groundwater level between Pre-monsoon and Post- monsoon have been prepared. First the change in groundwater storage is estimated for each successive strips of areas enclosed between two contours of groundwater level fluctuations. In this calculation Specific yield (Sy) values are adopted based on the local Geology. Areas between the contours are estimated through Arc GIS software package. All such storages are added to compute the total storage for the entire basin. In order to find out the percent of rainfall converted into groundwater storage as well as to find out the ground water recharge due to storageponds, a contour map of rainfall for the study area is prepared and areas between successive contours have been calculated. Based on the Geology map, Infiltration values are adopted for each successive strip of the contour area. Then the amount of water infiltrated into the ground is calculated by adjusting the infiltration values for each strip, so that the total infiltrated water for the entire basin is matched with change in Ground water storage, which is 1314.37 MCM for the upper Musi basin while it is 2827.29 MCM for entire Musi basin. With this procedure on an average 29.68 and 30.66 percent of Rainfall is converted into Groundwater recharge for Upper Musi and for entire Musi basin respectively. In the total recharge, the contribution of rainfall directly to

Monitoring recharge in areas of seasonally frozen ground in the Columbia Plateau and Snake River Plain, Idaho, Oregon, and Washington

Science.gov (United States)

Mastin, Mark; Josberger, Edward

2014-01-01

Seasonally frozen ground occurs over approximately one‑third of the contiguous United States, causing increased winter runoff. Frozen ground generally rejects potential groundwater recharge. Nearly all recharge from precipitation in semi-arid regions such as the Columbia Plateau and the Snake River Plain in Idaho, Oregon, and Washington, occurs between October and March, when precipitation is most abundant and seasonally frozen ground is commonplace. The temporal and spatial distribution of frozen ground is expected to change as the climate warms. It is difficult to predict the distribution of frozen ground, however, because of the complex ways ground freezes and the way that snow cover thermally insulates soil, by keeping it frozen longer than it would be if it was not snow covered or, more commonly, keeping the soil thawed during freezing weather. A combination of satellite remote sensing and ground truth measurements was used with some success to investigate seasonally frozen ground at local to regional scales. The frozen-ground/snow-cover algorithm from the National Snow and Ice Data Center, combined with the 21-year record of passive microwave observations from the Special Sensor Microwave Imager onboard a Defense Meteorological Satellite Program satellite, provided a unique time series of frozen ground. Periodically repeating this methodology and analyzing for trends can be a means to monitor possible regional changes to frozen ground that could occur with a warming climate. The Precipitation-Runoff Modeling System watershed model constructed for the upper Crab Creek Basin in the Columbia Plateau and Reynolds Creek basin on the eastern side of the Snake River Plain simulated recharge and frozen ground for several future climate scenarios. Frozen ground was simulated with the Continuous Frozen Ground Index, which is influenced by air temperature and snow cover. Model simulation results showed a decreased occurrence of frozen ground that coincided with

Ground-Motion Simulations of Scenario Earthquakes on the Hayward Fault

Energy Technology Data Exchange (ETDEWEB)

Aagaard, B; Graves, R; Larsen, S; Ma, S; Rodgers, A; Ponce, D; Schwartz, D; Simpson, R; Graymer, R

2009-03-09

We compute ground motions in the San Francisco Bay area for 35 Mw 6.7-7.2 scenario earthquake ruptures involving the Hayward fault. The modeled scenarios vary in rupture length, hypocenter, slip distribution, rupture speed, and rise time. This collaborative effort involves five modeling groups, using different wave propagation codes and domains of various sizes and resolutions, computing long-period (T > 1-2 s) or broadband (T > 0.1 s) synthetic ground motions for overlapping subsets of the suite of scenarios. The simulations incorporate 3-D geologic structure and illustrate the dramatic increase in intensity of shaking for Mw 7.05 ruptures of the entire Hayward fault compared with Mw 6.76 ruptures of the southern two-thirds of the fault. The area subjected to shaking stronger than MMI VII increases from about 10% of the San Francisco Bay urban area in the Mw 6.76 events to more than 40% of the urban area for the Mw 7.05 events. Similarly, combined rupture of the Hayward and Rodgers Creek faults in a Mw 7.2 event extends shaking stronger than MMI VII to nearly 50% of the urban area. For a given rupture length, the synthetic ground motions exhibit the greatest sensitivity to the slip distribution and location inside or near the edge of sedimentary basins. The hypocenter also exerts a strong influence on the amplitude of the shaking due to rupture directivity. The synthetic waveforms exhibit a weaker sensitivity to the rupture speed and are relatively insensitive to the rise time. The ground motions from the simulations are generally consistent with Next Generation Attenuation ground-motion prediction models but contain long-period effects, such as rupture directivity and amplification in shallow sedimentary basins that are not fully captured by the ground-motion prediction models.

Relation between ground water and surface water in the Hillsborough River basin, west-central Florida

Science.gov (United States)

Wolansky, R.M.; Thompson, T.H.

1987-01-01

The relation between groundwater and surface water in the Hillsborough River basin was defined through the use of: seismic-reflection profiling along selected reaches of the Hillsborough River, and evaluation of streamflow, rainfall, groundwater levels, water quality, and geologic data. Major municipal well fields in the basin are Morris Bridge and Cypress Creek where an averages of 15.3 and 30.0 million gal/day (mgd), respectively, were pumped in 1980. Mean annual rainfall for the study area is 53.7 inches. Average rainfall for 1980, determined from eight rainfall stations, was 49.7 inches. Evapotranspiration, corrected for the 5% of the basin that is standing water, was 35.7 in/year. The principal geohydrologic units in the basin are the surficial aquifer, the intermediate aquifer and confining beds, the Upper Floridan aquifer, the middle confining unit, and the Lower Floridan aquifer. Total pumpage of groundwater in 1980 was 98.18 mgd. The surficial aquifer and the intermediate aquifer are not used for major groundwater supply in the basin. Continuous marine seismic-reflection data collected along selected reaches of the Hillsborough River were interpreted to define the riverbed profile, the thickness of surficial deposits, and the top of persistent limestone. Major areas of groundwater discharge near the Hillsborough River and its tributaries are the wetlands adjacent to the river between the Zephyrhills gaging stations and Fletcher Avenue and the wetlands adjacent to Cypress Creek. An estimated 20 mgd seeps upward from the Upper Floridan aquifer within those wetland areas. The runoff/sq mi is greater at the Zephyrhills station than at Morris Bridge. However, results of groundwater flow models and potentiometric-surface maps indicate that groundwater is flowing upward along the Hillsborough River between the Zephyrhills gage and the Morris Bridge gage. This upward leakage is lost to evapotranspiration. An aquifer test conducted in 1978 at the Morris Bridge well

Phosphorus and water budgets in an agricultural basin.

Science.gov (United States)

Faridmarandi, Sayena; Naja, Ghinwa M

2014-01-01

Water and phosphorus (P) budgets of a large agricultural basin located in South Florida (Everglades Agricultural Area, EAA) were computed from 2005 to 2012. The annual surface outflow P loading from the EAA averaged 157.2 mtons originating from Lake Okeechobee (16.4 mtons, 10.4%), farms (131.0 mtons, 83.4%), and surrounding basins (9.8 mtons, 6.2%) after attenuation. Farms, urban areas, and the adjacent C-139 basin contributed 186.1, 15.6, and 3.8 mtons/yr P to the canals, respectively. The average annual soil P retention was estimated at 412.5 mtons. Water and P budgets showed seasonal variations with high correlation between rainfall and P load in drainage and surface outflows. Moreover, results indicated that the canals acted as a P sink storing 64.8 mtons/yr. To assess the P loading impact of farm drainage on the canals and on the outflow, dimensionless impact factors were developed. Sixty-two farms were identified with a high and a medium impact factor I1 level contributing 44.5% of the total drainage P load to the canals, while their collective area represented less than 23% of the EAA area (172 farms). Optimizing the best management practice (BMP) strategies on these farms could minimize the environmental impacts on the downstream sensitive wetlands areas.

The ShakeOut earthquake source and ground motion simulations

Science.gov (United States)

Graves, R.W.; Houston, Douglas B.; Hudnut, K.W.

2011-01-01

The ShakeOut Scenario is premised upon the detailed description of a hypothetical Mw 7.8 earthquake on the southern San Andreas Fault and the associated simulated ground motions. The main features of the scenario, such as its endpoints, magnitude, and gross slip distribution, were defined through expert opinion and incorporated information from many previous studies. Slip at smaller length scales, rupture speed, and rise time were constrained using empirical relationships and experience gained from previous strong-motion modeling. Using this rupture description and a 3-D model of the crust, broadband ground motions were computed over a large region of Southern California. The largest simulated peak ground acceleration (PGA) and peak ground velocity (PGV) generally range from 0.5 to 1.0 g and 100 to 250 cm/s, respectively, with the waveforms exhibiting strong directivity and basin effects. Use of a slip-predictable model results in a high static stress drop event and produces ground motions somewhat higher than median level predictions from NGA ground motion prediction equations (GMPEs).

Long-term impacts of variable retention harvesting on ground-layer plant communities in Pinus resinosa forests

Science.gov (United States)

Margaret W. Roberts; Anthony W. D' Amato; Christel C. Kern; Brian J. Palik; Lorenzo Marini

2016-01-01

Concerns about loss of biodiversity and structural complexity in managed forests have recently increased and led to the development of new management strategies focused on restoring or maintaining ecosystem functions while also providing wood outputs. Variable retention harvest (VRH) systems, in which mature overstorey trees are retained in various spatial arrangements...

Remedial investigation work plan for Bear Creek Valley Operable Unit 1 (S-3 Ponds, Boneyard/Burnyard, Oil Landfarm, Sanitary Landfill I, and the Burial Grounds, including Oil Retention Ponds 1 and 2) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1, Main text

International Nuclear Information System (INIS)

1994-03-01

This document refers to data concerning the Environmental Restoration Program implemented at the Oak Ridge Y-12 plant. Topics discussed include: Remediation plans for the burial grounds, sanitary landfill I, oil retention ponds, S-3 ponds, and the boneyard/burnyard at Y-12. This document also contains information about the environmental policies regulating the remediation

Handling effluent from nuclear thermal propulsion system ground tests

International Nuclear Information System (INIS)

Shipers, L.R.; Allen, G.C.

1992-01-01

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the different methods to handle effluent from nuclear thermal propulsion system ground tests

Using a map-based assesment tool for the development of cost-effective WFD river basin action programmes in a changing climate

DEFF Research Database (Denmark)

Kaspersen, Bjarke Stoltze; Vammen Jacobsen, Torsten; Brian Butts, Michael

2016-01-01

For the 2nd and 3rd river basin management cycles (2015–2027) of the Water Framework Directive (WFD), EU Member States are required to fully integrate climate change into the process of river basin management planning (RBMP). Complying with the main WFD objective of achieving ‘good ecological...... Basin in the north east of Denmark. The tool facilitates assessments of the application of agri-environmental measures that are targeted towards low retention agricultural areas, where limited or no surface and subsurface N reduction takes place. Effects of climate change on nitrate leaching were...... evaluated using the dynamic agro-ecosystem model ‘Daisy’. Results show that nitrate leaching rates increase by approx. 25% under current management practices. This impact outweighs the expected total N reduction effect of Baseline 2015 and the first RBMP in the case study river basin. The particular Po...

Ground water heat pumps and cooling with ground water basins as seasonal storage; Grundvandsvarmepumper og -koeling med grundvandsmagasiner som saesonlager

Energy Technology Data Exchange (ETDEWEB)

2008-04-15

Ground water temperature is constant all the year round, in Denmark approximately 9 deg. C, which is ideal for a number of cooling purposes including cooling of buildings. The structures in which the ground water flows (sand, gravel and chalk) are efficient for storing coldness and heat over longer periods. By using seasonal storage of low-temperature heat and coldness in ground water layers close to the terrain it is feasible to reach profitable energy savings of up to 90% for cooling and heating of e.g. hotels, airports, shopping malls, office buildings and other larger buildings. At the same time the large energy savings means major reduction of CO{sub 2} emissions. (BA)

EVALUASI RENCANA KINERJA KOLAM RETENSI (RETARDING BASIN DALAM UPAYA PENGENDALIAN BANJIR TUKAD MATI DI KOTA DENPASAR

Directory of Open Access Journals (Sweden)

I G. Suryadinata P

2013-03-01

Full Text Available Tukad Mati is one of the rivers in the province of Bali that unfolds and flows in Badung regency and Denpasar. Inundation due to flooding is a problem that often occurs in this region during the rainy season. In an effort to overcome problems of flooding have been many studies carried out so as to produce flood control alternatives such as normalization, diversion channels and retarding basins. Retarding basin is one of flood control alternative that has not been much studied. In this study conducted a simulation of flood prevention alternative with retarding basin at Tukad Mati, by the hydrology approach method and hydraulics using HEC-RAS 4.0 program applications. Simulations performed on the current river flow conditions (existing condition and to the existing conditions with the retarding basin, according to the detail design of retarding basin in the city of Denpasar and evaluate the effectiveness of the retarding basin in the river basin flood control of Tukad Mati. Flood control by retarding basin based on simulations with the 2 (two years flood return period, resulting in a reduction of water level by an average of 0.42 meters or an average of 12% of the maximum water level in the conditions without retarding basin, which occurred in along the grooves on the lower reaches of the retarding basin and inundation waters still occur in some places, particularly in the downstream of Umadui Dam. Economic analysis of both the analysis of Benefits/Cost produces a parameter of BCR, NPV and IRR are not meet the feasibility requirements. The effective retention of retarding basin based on simulation results are 282,630.00 m3 with the ability to flood accommodate for 3-4 hours. In terms of economic development retarding basin is not feasible in terms of comparative costs and benefits

EVALUASI RENCANA KINERJA KOLAM RETENSI (RETARDING BASIN DALAM UPAYA PENGENDALIAN BANJIR TUKAD MATI DI KOTA DENPASAR

Directory of Open Access Journals (Sweden)

I G. Suryadinata P

2013-01-01

Full Text Available Tukad Mati is one of the rivers in the province of Bali that unfolds and flows in Badung regency and Denpasar. Inundation due to flooding is a problem that often occurs in this region during the rainy season. In an effort to overcome problems of flooding have been many studies carried out so as to produce flood control alternatives such as normalization, diversion channels and retarding basins. Retarding basin is one of flood control alternative that has not been much studied. In this study conducted a simulation of flood prevention alternative with retarding basin at Tukad Mati, by the hydrology approach method and hydraulics using HEC-RAS 4.0 program applications. Simulations performed on the current river flow conditions (existing condition and to the existing conditions with the retarding basin, according to the detail design of retarding basin in the city of Denpasar and evaluate the effectiveness of the retarding basin in the river basin flood control of Tukad Mati. Flood control by retarding basin based on simulations with the 2 (two years flood return period, resulting in a reduction of water level by an average of 0.42 meters or an average of 12% of the maximum water level in the conditions without retarding basin, which occurred in along the grooves on the lower reaches of the retarding basin and inundation waters still occur in some places, particularly in the downstream of Umadui Dam. Economic analysis of both the analysis of Benefits/Cost produces a parameter of BCR, NPV and IRR are not meet the feasibility requirements. The effective retention of retarding basin based on simulation results are 282,630.00 m3 with the ability to flood accommodate for 3-4 hours. In terms of economic development retarding basin is not feasible in terms of comparative costs and benefits

The biotest basin of the Forsmark nuclear power plant, Sweden. An experiment on the ecosystem level

International Nuclear Information System (INIS)

Grimaas, U.

1979-01-01

Biotope models of various sizes and enclosed waters in connection with radionuclide release constitute important tools for radioecological experiments, representing an intermediate step between field and laboratory conditions. The biotest basin at Forsmark is especially constructed for investigations on the effects of radioactivity and heat on a brackish water ecosystem. The basin encloses a water area of 1km 2 in the outer archipelago of the region and is fed with cooling water and released radionuclides by a discharge tunnel. The quantities of the discharges into the basin are adjustable. The biotest experiment permits a quantification of the retention and transport of radionuclides at the various trophic levels. Of special value is the possibility to work with known populations of fish. The approach has the advantage of experimental ecology - the control of important parameters - under the impact of all environmental factors in a complete ecosystem. (author)

Basin amplification of seismic waves in the city of Pahrump, Nevada.

Energy Technology Data Exchange (ETDEWEB)

Abbott, Robert E.

2005-07-01

Sedimentary basins can increase the magnitude and extend the duration of seismic shaking. This potential for seismic amplification is investigated for Pahrump Valley, Nevada-California. The Pahrump Valley is located approximately 50 km northwest of Las Vegas and 75 km south of the Nevada Test Site. Gravity data suggest that the city of Pahrump sits atop a narrow, approximately 5 km deep sub-basin within the valley. The seismic amplification, or ''site effect'', was investigated using a combination of in situ velocity modeling and comparison of the waveforms and spectra of weak ground motion recorded in the city of Pahrump, Nevada, and those recorded in the nearby mountains. Resulting spectral ratios indicate seismic amplification factors of 3-6 over the deepest portion of Pahrump Valley. This amplification predominantly occurs at 2-2.5 Hz. Amplification over the deep sub-basin is lower than amplification at the sub-basin edge, location of the John Blume and Associates PAHA seismic station, which recorded many underground nuclear tests at the Nevada Test Site. A comprehensive analysis of basin amplification for the city of Pahrump should include 3-D basin modeling, due to the extreme basement topography of the Pahrump Valley.

Quantification and Postglacial evolution of an inner alpine sedimentary basin (Gradenmoos Basin, Hohe Tauern)

International Nuclear Information System (INIS)

Götz, J.

2012-01-01

The overall objective of this thesis is the quantification of sediment storage and the reconstruction of postglacial landscape evolution within the glacially overdeepened Gradenmoos Basin (subcatchment size: 4.1 km 2 ; basin floor elevation: 1920 m) in the central Gradenbach catchment (Schober Range, Hohe Tauern, Austrian Alps). Following the approach of denudation-accumulation-systems, most reliable results are obtained (1) if sediment output of a system can be neglected for an established period of time, (2) if sediment storage can be assessed with a high level of accuracy, (3) if the onset of sedimentation and amounts of initially stored sediments are known, and (4) if sediment contributing areas can be clearly delimited. Due to spatial scale and topographic characteristics, all mentioned aspects are fulfilled to a high degree within the studied basin. Applied methods include surface, subsurface and temporal investigations. Digital elevation data is derived from terrestrial laserscanning and geomorphologic mapping. The quantification of sediment storage is based on core drillings, geophysical methods (DC resistivity, refraction seismic, and ground penetrating radar), as well as GIS and 3D modelling. Radiocarbon dating and palynological analyses are additionally used to reconstruct the postglacial infilling progress of the basin. The study reveals that a continuous postglacial stratigraphic record is archived in the basin. As proposed by Lieb (1987) timing of basin deglaciation could be verified to late-Egesen times by means of radiocarbon ages (oldest sample just above basal till: 10.4 ka cal. BP) and first palynologic results. Lateglacial oscillations seem to have effectively scoured the basin, leaving only a shallow layer of basal till. The analysis of postglacial sedimentation in the basin is further improved by the existence of a former lake in the basin lasting for up to 7500 years until approx. 3.7 ka cal. BP. Both, the stratigraphic (fine, partly

Environmental Setting of the Lower Merced River Basin, California

Science.gov (United States)

Gronberg, Jo Ann M.; Kratzer, Charles R.

2006-01-01

In 1991, the U.S. Geological Survey began to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology as part of the National Water-Quality Assessment (NAWQA) Program. As part of this program, the San Joaquin-Tulare Basins study unit is assessing parts of the lower Merced River Basin, California. This report provides descriptions of natural and anthropogenic features of this basin as background information to assess the influence of these and other factors on water quality. The lower Merced River Basin, which encompasses the Mustang Creek Subbasin, gently slopes from the northeast to the southwest toward the San Joaquin River. The arid to semiarid climate is characterized by hot summers (highs of mid 90 degrees Fahrenheit) and mild winters (lows of mid 30 degrees Fahrenheit). Annual precipitation is highly variable, with long periods of drought and above normal precipitation. Population is estimated at about 39,230 for 2000. The watershed is predominately agricultural on the valley floor. Approximately 2.2 million pounds active ingredient of pesticides and an estimated 17.6 million pounds active ingredient of nitrogen and phosphorus fertilizer is applied annually to the agricultural land.

Multiscale sagebrush rangeland habitat modeling in the Gunnison Basin of Colorado

Science.gov (United States)

Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Schell, Spencer J.

2013-01-01

North American sagebrush-steppe ecosystems have decreased by about 50 percent since European settlement. As a result, sagebrush-steppe dependent species, such as the Gunnison sage-grouse, have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, is needed to help maintain existing sagebrush habitats; however, products that accurately model and map sagebrush habitats in detail over the Gunnison Basin in Colorado are still unavailable. The goal of this project is to provide a rigorous large-area sagebrush habitat classification and inventory with statistically validated products and estimates of precision across the Gunnison Basin. This research employs a combination of methods, including (1) modeling sagebrush rangeland as a series of independent objective components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground measured plot data on 2.4-meter QuickBird satellite imagery in the same season the imagery is acquired; (3) modeling of ground measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of Landsat Thematic Mapper imagery (30-meter) for optimal modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution Landsat Thematic Mapper; and 6) employing accuracy assessment of model predictions to enable users to understand their dependencies. Results include the prediction of four primary components including percent bare ground, percent herbaceous, percent shrub, and percent litter, and four secondary components including percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata wyomingensis), and shrub height (centimeters

Ground subsidence and associated ground fracturing in urban areas: InSAR monitoring of active tectonic structures (Ciudad Guzman, Colima Graben - Mexico)

Science.gov (United States)

Bignami, C.; Brunori, C.; Zucca, F.; Groppelli, G.; Norini, G.; Hernandez, N. D.; Stramondo, S.

2013-12-01

This study focuses on the observation of a creeping phenomenon that produces subsidence of the Zapotlan basin and ground fracturing in correspondence of the Ciudad Guzmàn (Jalisco - Mexico). The September 21, 2012, the Ciudad Guzmàn has been struck by a phenomenon of ground fracturing of about 1.5 km of length. This event caused the deformation of the roads and the damage of 30 houses, of which eight have been declared uninhabitable. The alignment of fractures is coincident with the escarpments produced in September 19, 1985, in the Ciudad Guzman urban area, when a strong earthquake, magnitude 8.1, struck the Mexican area, causing the deaths of at least 10,000 people and serious damage in Mexico City. In Ciudad Guzmán, about 60% of the buildings were destroyed, with about 50 loss of life. The city is located in the Zapotlan basin (northern Colima graben), a wide tectonic depression where the depth of the infilling sediments is about 1 km. This subsidence cannot be measured outside the urbanized area, but it can be considered as a deformation mechanism of the central part of the basin. In order to detect and mapping the spatio-temporal features of the processes that led to this event, we applied InSAR multi-temporal techniques to analyze a dataset of ENVISAT satellite SAR images, acquired in a time span between 2003-2010. InSAR techniques detect a subsidence of the north-western part of Ciudad Guzmàn of about 15 mm/yr in the time interval 2003-2010. The displacement occurred in September 21, 2012, was detected using two RadarSAT2 acquisitions (2012-03-22 and 2013-03-17). The explanation of surface movements based on interferometric results, ground data and geological field observations, allowed confirming surface effect due to the overexploitation of the aquifers and highlights a subsidence due to anthropogenic causes coupled to buried tectonic structures.

Studies of geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste - Basis of characterization and evaluation

Science.gov (United States)

Bedinger, M.S.; Sargent, K.A.; Langer, William H.; Sherman, Frank B.; Reed, J.E.; Brady, B.T.

1989-01-01

The geologic and hydrologic factors in selected regions of the Basin and Range province were examined to identify prospective areas for further study that may provide isolation of high-level radioactive waste from the accessible environment. The six regions selected for study were characterized with respect to the following guidelines: (1) Potential repository media; (2) Quaternary tectonic conditions; (3) climatic change and geomorphic processes; (4) ground-water conditions; (5) ground-water quality; and (6) mineral and energy resources.The repository medium will function as the first natural barrier to radionuclide travel by virtue of associated slow ground-water velocity. The principal rock types considered as host media include granitic, intermediate, and mafic intrusive rocks; argillaceous rocks; salt and anhydrite; volcanic mudflow (laharic) breccias; some intrusive rhyolitic plugs and stocks; partially zeolitized tuff; and metamorphic rocks. In the unsaturated zone, the permeability and hydrologic properties of the rocks and the hydrologic setting are more important than the rock type. Media ideally should be permeable to provide drainage and should have a minimal water fluxThe ground-water flow path from a repository to the accessible environment needs to present major barriers to the transport of radionuclides. Factors considered in evaluating the ground-water conditions include ground-water traveltimes and quality, confining beds, and earth materials favorable for retardation of radionuclides. Ground-water velocities in the regions were calculated from estimated hydraulic properties of the rocks and gradients. Because site-specific data on hydraulic properties are not available, data from the literature were assembled and synthesized to obtain values for use in estimating ground-water velocities. Hydraulic conductivities for many rock types having granular and fracture permeability follow a log-normal distribution. Porosity for granular and very weathered

Sampling and Analysis Plan for K Basins Debris

International Nuclear Information System (INIS)

WESTCOTT, J.L.

2000-01-01

This Sampling and Analysis Plan presents the rationale and strategy for sampling and analysis activities to support removal of debris from the K-East and K-West Basins located in the 100K Area at the Hanford Site. This project is focused on characterization to support waste designation for disposal of waste at the Environmental Restoration Disposal Facility (ERDF). This material has previously been dispositioned at the Hanford Low-Level Burial Grounds or Central Waste Complex. The structures that house the basins are classified as radioactive material areas. Therefore, all materials removed from the buildings are presumed to be radioactively contaminated. Because most of the materials that will be addressed under this plan will be removed from the basins, and because of the cost associated with screening materials for release, it is anticipated that all debris will be managed as low-level waste. Materials will be surveyed, however, to estimate radionuclide content for disposal and to determine that the debris is not contaminated with levels of transuranic radionuclides that would designate the debris as transuranic waste

Characterization of hydraulic conductivity of the alluvium and basin fill, Pinal Creek Basin near Globe, Arizona

Science.gov (United States)

Angeroth, Cory E.

2002-01-01

Acidic waters containing elevated concentrations of dissolved metals have contaminated the regional aquifer in the Pinal Creek Basin, which is in Gila County, Arizona, about 100 kilometers east of Phoenix. The aquifer is made up of two geologic units: unconsolidated stream alluvium and consolidated basin fill. To better understand how contaminants are transported through these units, a better understanding of the distribution of hydraulic conductivity and processes that affect it within the aquifer is needed. Slug tests were done in September 1997 and October 1998 on 9 wells finished in the basin fill and 14 wells finished in the stream alluvium. Data from the tests were analyzed by using either the Bouwer and Rice (1976) method, or by using an extension to the method developed by Springer and Gellhar (1991). Both methods are applicable for unconfined aquifers and partially penetrating wells. The results of the analyses show wide variability within and between the two geologic units. Hydraulic conductivity estimates ranged from 0.5 to 250 meters per day for the basin fill and from 3 to 200 meters per day for the stream alluvium. Results of the slug tests also show a correlation coefficient of 0.83 between the hydraulic conductivity and the pH of the ground water. The areas of highest hydraulic conductivity coincide with the areas of lowest pH, and the areas of lowest hydraulic conductivity coincide with the areas of highest pH, suggesting that the acidic water is increasing the hydraulic conductivity of the aquifer by dissolution of carbonate minerals.

High density NOAA time series of ET in the Gediz Basin, Turkey

NARCIS (Netherlands)

Gieske, A.; Meijninger, W.M.L.

2005-01-01

An evapotranspiration method comparison was carried out by the International Water Management Institute (IWMI, Sri Lanka), at two locations in the Gediz Basin, Turkey, in the period from May to September 1998. In the IWMI study a number of ground-based techniques were compared with results obtained

Mapping ground surface deformation using temporarily coherent point SAR interferometry: Application to Los Angeles Basin

Science.gov (United States)

Zhang, L.; Lu, Zhong; Ding, X.; Jung, H.-S.; Feng, G.; Lee, C.-W.

2012-01-01

Multi-temporal interferometric synthetic aperture radar (InSAR) is an effective tool to detect long-term seismotectonic motions by reducing the atmospheric artifacts, thereby providing more precise deformation signal. The commonly used approaches such as persistent scatterer InSAR (PSInSAR) and small baseline subset (SBAS) algorithms need to resolve the phase ambiguities in interferogram stacks either by searching a predefined solution space or by sparse phase unwrapping methods; however the efficiency and the success of phase unwrapping cannot be guaranteed. We present here an alternative approach – temporarily coherent point (TCP) InSAR (TCPInSAR) – to estimate the long term deformation rate without the need of phase unwrapping. The proposed approach has a series of innovations including TCP identification, TCP network and TCP least squares estimator. We apply the proposed method to the Los Angeles Basin in southern California where structurally active faults are believed capable of generating damaging earthquakes. The analysis is based on 55 interferograms from 32 ERS-1/2 images acquired during Oct. 1995 and Dec. 2000. To evaluate the performance of TCPInSAR on a small set of observations, a test with half of interferometric pairs is also performed. The retrieved TCPInSAR measurements have been validated by a comparison with GPS observations from Southern California Integrated GPS Network. Our result presents a similar deformation pattern as shown in past InSAR studies but with a smaller average standard deviation (4.6 mm) compared with GPS observations, indicating that TCPInSAR is a promising alternative for efficiently mapping ground deformation even from a relatively smaller set of interferograms.

Numerical modeling of ground-water flow systems in the vicinity of the reference repository location, Hanford Site, Washington

International Nuclear Information System (INIS)

Davis, P.; Beyeler, W.; Logsdon, M.; Coleman, N.; Brinster, K.

1989-04-01

This report documents south-central Washington State's Pasco Basin ground-water modeling studies. This work was done to support the NRC's review of hydrogeologic studies under the Department of Energy's (DOE) Basalt Waste Isolation Project. The report provides a brief overview of the geology, hydrology, and hydrochemistry of the Pasco Basin as a basis for the evaluation of previous conceptual and numerical ground-water flow models of the region. Numerical models were developed to test new conceptual models of the site and to provide a means of evaluating the Department of Energy's performance assessments and proposed hydrologic testing. Regional ground-water flow modeling of an area larger than the Pasco Basin revealed that current concepts on the existence and behavior of a hydrologic barrier west of the proposed repository location are inconsistent with available data. This modeling also demonstrated that the measured pattern of hydraulic heads cannot be produced with a model that (1) has uniform layer properties over the entire domain; (2) has zones of large conductivity associated with anticlinal structures; or (3) includes recharge from the industrial disposal ponds. Adequate representation of the measured hydraulic heads was obtained with a model that contained regions of larger hydraulic conductivity that corresponded to the presence of sedimentary interbeds. In addition, a detailed model of a region smaller than the Pasco Basin was constructed to provide the NRC staff with the ability to analyze proposed Department of Energy hydrologic tests. 62 refs., 145 figs., 18 tabs

Effluent treatment options for nuclear thermal propulsion system ground tests

International Nuclear Information System (INIS)

Shipers, L.R.; Brockmann, J.E.

1992-01-01

A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests

Process-based modelling of phosphorus transformations and retention in global rivers

Science.gov (United States)

Vilmin, Lauriane; Mogollon, Jose; Beusen, Arthur; Bouwman, Lex

2016-04-01

Phosphorus (P) plays a major role in the biogeochemical functioning of aquatic systems. It typically acts as the limiting nutrient for primary productivity in freshwater bodies, and thus the increase in anthropogenic P loads during the XXth century has fuelled the eutrophication of these systems. Total P retention in global rivers has also escalated over this timeframe as demonstrated via a global model that implements the spiralling method at a spatial resolution of 0.5° (IMAGE-GNM, Beusen et al., 2015). Here, we refine this coupled hydrological - nutrient model by including mechanistic biogeochemical interactions that govern the P cycle. Special attention is paid to the representation of particle processes (i.e. particle loading, sedimentation and erosion), which play a major role in P transport and accumulation in aquatic systems. Our preliminary results are compared to measurements of suspended sediments, total P and orthophosphates in selected river basins. Initial model results show that P concentrations are particularly sensitive to particulate load distribution in the river network within a grid cell. This novel modelling approach will eventually allow a better assessment of the amounts of different forms of P (organic P, soluble reactive P, and particulate inorganic P), of P transformation rates and retention in inland waters. References Beusen, A.H.W., Van Beek, L.P.H., Bouwman, A.F., Mogollón, J.M., Middelburg, J.J. 2015. Coupling global models for hydrology and nutrient loading to simulate nitrogen and phosphorus retention in surface water - description of the IMAGE-GNM and analysis of performance. Geosci. Model Dev. 8, 4045-4067

Urinary retention in women.

Science.gov (United States)

Juma, Saad

2014-07-01

This review is a summary of the most pertinent published studies in the literature in the last 18 months that address cause, diagnosis, and management of urinary retention in women. Symptoms, uroflow, and pressure-flow studies have a low predictive value for and do not correlate with elevated postvoid residual urine (PVR). Anterior and posterior colporrhaphy do not cause de-novo bladder outlet obstruction in the majority of patients with elevated PVR, and the cause of elevated PVR may be other factors such as pain or anxiety causing abnormal relaxation of the pelvic floor and contributing to voiding difficulty. The risk of urinary retention in a future pregnancy after mid-urethral sling (MUS) is small. The risk of urinary tract infection and urinary retention after chemodenervation of the bladder with onabotulinumtoxin-A (100 IU) in patients with non-neurogenic urge incontinence is 33 and 5%, respectively. There is a lack of consensus among experts on the timing of sling takedown in the management of acute urinary retention following MUS procedures. There has been a significant progress in the understanding of the causation of urinary retention. Important areas that need further research (basic and clinical) are post-MUS and pelvic organ prolapse repair urinary retention and obstruction, and urinary retention owing to detrusor underactivity.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico

Energy Technology Data Exchange (ETDEWEB)

Fenn, M.E. [USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, 4955 Canyon Crest Dr., Riverside, CA 92507 (United States)]. E-mail: mfenn@fs.fed.us; Perea-Estrada, V.M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico); Bauer, L.I. de [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico)]. E-mail: libauer@colpos.mx; Perez-Suarez, M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico); Parker, D.R. [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States)]. E-mail: david.parker@ucr.edu; Cetina-Alcala, V.M. [Instituto de Recursos Naturales, Colegio de Postgraduados, CP 56230 Montecillo (Mexico)

2006-03-15

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols. - Plant response to N deposition may be limited by P limitation in forests growing on Andisol soils in the Basin of Mexico.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico

International Nuclear Information System (INIS)

Fenn, M.E.; Perea-Estrada, V.M.; Bauer, L.I. de; Perez-Suarez, M.; Parker, D.R.; Cetina-Alcala, V.M.

2006-01-01

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols. - Plant response to N deposition may be limited by P limitation in forests growing on Andisol soils in the Basin of Mexico

Yield and quality of ground water from stratified-drift aquifers, Taunton River basin, Massachusetts : executive summary

Science.gov (United States)

Lapham, Wayne W.; Olimpio, Julio C.

1989-01-01

Water shortages are a chronic problem in parts of the Taunton River basin and are caused by a combination of factors. Water use in this part of the Boston metropolitan area is likely to increase during the next decade. The Massachusetts Division of Water Resources projects that about 50% of the cities and towns within and on the perimeter of the basin may have water supply deficits by 1990 if water management projects are not pursued throughout the 1980s. Estimates of the long-term yield of the 26 regional aquifers indicate that the yields of the two most productive aquifers equal or exceed 11.9 and 11.3 cu ft/sec, 90% of the time, respectively, if minimum stream discharge is maintained at 99.5% flow duration. Eighteen of the 26 aquifers were pumped for public water supply during 1983. Further analysis of the yield characteristics of these 18 aquifers indicates that the 1983 pumping rate of each of these 18 aquifers can be sustained at least 70% of the time. Selected physical properties and concentrations of major chemical constituents in groundwater from the stratified-drift aquifers at 80 sampling sites were used to characterize general water quality in aquifers throughout the basin. The pH of the groundwater ranged from 5.4 to 7.0. Natural elevated concentrations of Fe and Mn in water in the stratified-drift aquifers are present locally in the basin. Natural concentrations of these two metals commonly exceed the limits of 0.3 mg/L for Fe and 0.05 mg/L for Mn recommended for drinking water. Fifty-one analyses of selected trace metals in groundwater samples from stratified-drift aquifers throughout the basin were used to characterize trace metal concentrations in the groundwater. Of the 10 constituents sampled that have US EPA limits recommended for drinking water, only the Pb concentration in water at one site (60 micrograms/L) exceeded the recommended limit of 50 micrograms/L. Analyses of selected organic compounds in water in the stratified-drift aquifers at 74

Verification and Improvement of the Three-Dimensional Basin Velocity Structure Model in the Osaka Sedimentary Basin, Japan Using Interstation Green's Functions and H/V Spectral Ratios of Microtremors

Science.gov (United States)

Asano, K.; Iwata, T.; Sekiguchi, H.; Somei, K.; Nishimura, T.; Miyakoshi, K.; Aoi, S.; Kunugi, T.

2012-12-01

The Osaka sedimentary basin is filled by the Plio-Pleistocene Osaka group, terrace deposits, and alluvium deposits with thickness of 1 to 2 km over the bedrock, and it is surrounded by active fault systems. The Uemachi active fault system underlies the Osaka urban area. In order to predict the strong ground motions for future events of the Uemachi fault and others, the precise basin velocity structure model is indispensable as well as the detailed source fault model. The velocity structure of the Osaka basin has been extensively investigated by using various techniques such as gravity anomaly measurements, reflection surveys, boring explorations, and microtremor measurements. Based on these surveys and ground motion simulations for observed events, the three-dimensional velocity structure models of the Osaka basin have been developed and improved for decades (e.g., Kagawa et al., 1993; Horikawa et al., 2003; Iwata et al., 2008; Iwaki and Iwata, 2011). Now we are trying to verify the velocity structure model of the Osaka basin and to improve it incorporating new data sets. We have conducted two kinds of observations in the Osaka basin. The first observation is continuous microtremor observation. We have temporarily installed three-component velocity sensors at 15 sites covering the Osaka basin to record microtremors continuously for more than one year. The seismic interferometry technique (e.g. Shapiro and Campillo, 2004) is applied to retrieve interstation Green's function for analyzing the wave propagation characteristics inside the sedimentary basin. Both Rayleigh- and Love-wave type signals are identified in 0.1-0.5 Hz from observed interstation Green's functions. The group velocities of Rayleigh and Love waves propagating between two stations are estimated from them using the multiple filter analysis method, and they are compared with the theoretical group-velocities of the model. For example, estimated Love-wave group velocity along a line inside the basin is

Shallow ground water in the Powder River Bbasin, northeastern Wyoming: Description of selected publications, 1950-91, and indications for further study. Water Resources Investigation

International Nuclear Information System (INIS)

Lindner-Lunsford, J.B.; Wilson, J.F.

1992-01-01

The report describes the conclusions and contributions to knowledge of shallow ground water in publications resulting from previous ground-water investigations in the Powder River Basin and describes indications for further study. For the report, shallow ground water is defined as water in geologic formations overlying the Upper Cretaceous Pierre Shale and equivalents. The 76 publications described were produced from 1950-91 by the U.S. Geological Survey, other government agencies, and academic and private organizations, including mining companies and engineering consultants. Only those parts of the publications that are relevant to thee quantity or quality of shallow ground water in the Powder River Basin are described. Mine plans for coal and uranium mines (many of which contain detailed, local hydrologic information) and publications containing pertinent geologic information, but no hydrologic information, are not included

Radon measurements along active faults in the Langadas Basin, northern Greece

Directory of Open Access Journals (Sweden)

C. Papastefanou

2001-01-01

Full Text Available A network of three radon stations has been established in the Langadas Basin, northern Greece for radon monitoring by various techniques in earthquake prediction studies. Specially made devices with plastic tubes including Alpha Tracketch Detectors (ATD were installed for registering alpha particles from radon and radon decay products exhaled from the ground, every 2 weeks, by using LR-115, type II, non-strippable Kodak films, starting from December 1996. Simultaneous measurements started using Lucas cells alpha spectrometer for instantaneous radon measurements in soil gas, before and after setting ATDs at the radon stations. Continuous monitoring of radon gas exhaling from the ground started from the middle of August 1999 by using silicon diode detectors, which simultaneously register meteorological parameters, such as rainfall, temperature and barometric pressure. The obtained data were studied together with the data of seismic events, such as the magnitude, ML, of earthquakes that occurred at the Langadas Basin during the period of measurements, as registered by the Laboratory of Geophysics, Aristotle University of Thessaloniki, in order to find out any association between them.

Data Quality Objectives Process for Designation of K-Basins Debris

International Nuclear Information System (INIS)

WESTCOTT, J.L.

2000-01-01

The U.S. Department of Energy has developed a schedule and approach for the removal of spent fuels, sludge, and debris from the K East (KE) and K West (KW) Basins, located in the 100 Area at the Hanford Site. The project that is the subject of this data quality objective (DQO) process is focused on the removal of debris from the K Basins and onsite disposal of the debris at the Environmental Restoration Disposal Facility (ERDF). This material previously has been dispositioned at the Hanford Low-Level Burial Grounds (LLBGs) or Central Waste Complex (CWC). The goal of this DQO process and the resulting Sampling and Analysis Plan (SAP) is to provide the strategy for characterizing and designating the K-Basin debris to determine if it meets the Environmental Restoration Disposal Facility Waste Acceptance Criteria (WAC), Revision 3 (BHI 1998). A critical part of the DQO process is to agree on regulatory and WAC interpretation, to support preparation of the DQO workbook and SAP

Hydrogeology of an ancient arid closed basin: Implications for tabular sandstone-hosted uranium deposits

International Nuclear Information System (INIS)

Sanford, R.F.

1990-01-01

Hydrogeologic modeling shows that tabular-type uranium deposits in the grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat

Mathematical Modeling of Fate and Transport of Aqueous Species in Stormflow Entering Infiltration Basin.

Science.gov (United States)

Massoudieh, A.; Sengor, S. S.; Meyer, S.; Ginn, T. R.

2004-12-01

The State of California is evaluating the role of passive stormwater detention facilities for the purpose of attenuating potential dissolved and suspended chemical species that may originate in roadway runoff of rainfall. The engineering design of such infiltration basins requires tools to quantify their performance as recipients of stormwater runoff from roadways, and as filters of aqueous chemical species. For this purpose a one-dimensional unsaturated flow and transport model is developed to estimate the efficiency of storm-water infiltration basins in treating roadway generated metallic and organic pollutants. Kinematic wave approximation is used along with van Genuchten water retention model to simulate water percolation thorough the infiltration basin. For metals a Langmuir type nonlinear competitive sorption isotherm is used for transport of chemicals and a kinetic reversible linear sorption model is considered for organics. The model is applied to known roadway born metallic contaminations such as copper, zinc, lead, chromium, nickel and cadmium, as well as organic species such as diazinon, diuron, ghlyphosate and pyrene, for several representative soil and precipitation condition for California within a period of five years. Representative soil parameters and precipitation patterns are extracted from frequency distributions extracted from a recent study. In addition sensitivity analysis has been done to evaluate the effect of soil property values on the performance of infiltration basins. The results can be used to evaluate the performance of infiltration basins in improving the water quality as well as being used in providing guidelines in design and maintenance of infiltration basins.

Geohydrology and numerical simulation of groundwater flow in the central Virgin River Basin of Iron and Washington Counties, Utah

Science.gov (United States)

Heilweil, V.M.; Freethey, G.W.; Wilkowske, C.D.; Stolp, B.J.; Wilberg, D.E.

2000-01-01

Because rapid growth of communities in Washington and Iron Counties, Utah, is expected to cause an increase in the future demand for water resources, a hydrologic investigation was done to better understand ground-water resources within the central Virgin River basin. This study focused on two of the principal ground-water reservoirs within the basin: the upper Ash Creek basin ground-water system and the Navajo and Kayenta aquifer system.The ground-water system of the upper Ash Creek drainage basin consists of three aquifers: the uppermost Quaternary basin-fill aquifer, the Tertiary alluvial-fan aquifer, and the Tertiary Pine Valley monzonite aquifer. These aquifers are naturally bounded by the Hurricane Fault and by drainage divides. On the basis of measurements, estimates, and numerical simulations of reasonable values for all inflow and outflow components, total water moving through the upper Ash Creek drainage basin ground-water system is estimated to be about 14,000 acre-feet per year. Recharge to the upper Ash Creek drainage basin ground-water system is mostly from infiltration of precipitation and seepage from ephemeral and perennial streams. The primary source of discharge is assumed to be evapotranspiration; however, subsurface discharge near Ash Creek Reservoir also may be important.The character of two of the hydrologic boundaries of the upper Ash Creek drainage basin ground-water system is speculative. The eastern boundary provided by the Hurricane Fault is assumed to be a no-flow boundary, and a substantial part of the ground-water discharge from the system is assumed to be subsurface outflow beneath Ash Creek Reservoir along the southern boundary. However, these assumptions might be incorrect because alternative numerical simulations that used different boundary conditions also proved to be feasible. The hydrogeologic character of the aquifers is uncertain because of limited data. Differences in well yield indicate that there is considerable

Evaluating Potential Tipping Points of Antarctic basins

Science.gov (United States)

Durand, G.; Sainan, S.; Pattyn, F.; Jourdain, N.

2017-12-01

Antarctica is currently loosing mass and its forthcoming contribution to sea-level rise could substantially increase during the coming centuries. This is essentially due to geometrical constraints, i.e., in regions where grounded ice lies on a bedrock below sea-level sloping down towards the interior of the ice sheet (retrograde slope). For such a configuration the ice sheet is considered potentially unstable, as suggested by theory. However, recent observations on accelerated grounding-line retreat and new insights in modeling Pine Island and Thwaites glaciers give evidence that such self-sustained retreat, called marine ice sheet instability (MISI), has already been on its way. Although West Antarctica appears to be the most vulnerable region for MISI occurrence, similar topographic configurations are also observed in East Antarctica, in the Wilkes Basin in particular. Therefore, evaluating the MISI potential at a pan-Antarctic scale is becoming a priority. Here, using the f.ETISh ice sheet model, an ensemble of simulations of the entire contemporary Antarctic ice sheet has been carried out. In particular, we investigate the debuttressing of ice shelves required to initiate MISI for each coastal region around Antarctica by forcing the model with realistic sub-shelf melt pulses of varying duration and amplitude. We further identify the currently grounded areas where the outlet glaciers could hardly stabilize, the Amundsen Sea Sector being the more prone to large self-sustained retreats. On the contrary, the ability of Cook and Ninnis ice shelves to recover after large perturbations and enough buttress upstream outlet glaciers tends to limit self-sustained retreat of the sector. For each basin, rates of contribution to sea-level rise are discussed together with the RCPs and time when tipping points could be reached and MISI triggered.

The Ogaden Basin, Ethiopia: an underexplored sedimentary basin

Energy Technology Data Exchange (ETDEWEB)

Teitz, H.H.

1991-01-01

A brief article examines the Ogaden Basin in Ethiopia in terms of basin origin, basin fill and the hydrocarbon exploration history and results. The natural gas find in pre-Jurassic sandstones, which appears to contain substantial reserves, justifies continuing investigations in this largely underexplored basin. (UK).

Hydrologic and Water-Quality Responses in Shallow Ground Water Receiving Stormwater Runoff and Potential Transport of Contaminants to Lake Tahoe, California and Nevada, 2005-07

Science.gov (United States)

Green, Jena M.; Thodal, Carl E.; Welborn, Toby L.

2008-01-01

Clarity of Lake Tahoe, California and Nevada has been decreasing due to inflows of sediment and nutrients associated with stormwater runoff. Detention basins are considered effective best management practices for mitigation of suspended sediment and nutrients associated with runoff, but effects of infiltrated stormwater on shallow ground water are not known. This report documents 2005-07 hydrogeologic conditions in a shallow aquifer and associated interactions between a stormwater-control system with nearby Lake Tahoe. Selected chemical qualities of stormwater, bottom sediment from a stormwater detention basin, ground water, and nearshore lake and interstitial water are characterized and coupled with results of a three-dimensional, finite-difference, mathematical model to evaluate responses of ground-water flow to stormwater-runoff accumulation in the stormwater-control system. The results of the ground-water flow model indicate mean ground-water discharge of 256 acre feet per year, contributing 27 pounds of phosphorus and 765 pounds of nitrogen to Lake Tahoe within the modeled area. Only 0.24 percent of this volume and nutrient load is attributed to stormwater infiltration from the detention basin. Settling of suspended nutrients and sediment, biological assimilation of dissolved nutrients, and sorption and detention of chemicals of potential concern in bottom sediment are the primary stormwater treatments achieved by the detention basins. Mean concentrations of unfiltered nitrogen and phosphorus in inflow stormwater samples compared to outflow samples show that 55 percent of nitrogen and 47 percent of phosphorus are trapped by the detention basin. Organic carbon, cadmium, copper, lead, mercury, nickel, phosphorus, and zinc in the uppermost 0.2 foot of bottom sediment from the detention basin were all at least twice as concentrated compared to sediment collected from 1.5 feet deeper. Similarly, concentrations of 28 polycyclic aromatic hydrocarbon compounds were

Purification of arsenic contaminated ground water using hydrated manganese dioxide

International Nuclear Information System (INIS)

Raje, N.; Swain, K.K.

2002-01-01

An analytical methodology has been developed for the separation of arsenic from ground water using inorganic material in neutral medium. The separation procedure involves the quantitative retention of arsenic on hydrated manganese dioxide, in neutral medium. The validity of the separation procedure has been checked by a standard addition method and radiotracer studies. Neutron activation analysis (NAA), a powerful measurement technique, has been used for the quantitative determination of arsenic. (author)

Analysis of change of retention capacity of a small water reservoir

Science.gov (United States)

Výleta, R.; Danáčová, M.; Valent, P.

2017-10-01

This study is focused on the analysis of the changes of retention capacity of a small water reservoir induced by intensive erosion and sedimentation processes. The water reservoir is situated near the village of Vrbovce in the Western part of Slovakia, and the analysis is carried out for a period 2008-2017. The data used to build a digital elevation model (DEM) of the reservoir’s bed came from a terrain measurement, utilizing an acoustic Doppler current profiler (ADCP) to measure the water depth in the reservoir. The DEM was used to quantify the soil loss from agricultural land situated within the basin of the reservoir. The ability of the water reservoir to transform a design flood with a return period of 100 years is evaluated for both design (2008) and current conditions (2017). The results show that the small water reservoir is a subject to siltation, with sediments comprised of fine soil particles transported from nearby agricultural land. The ability of the water reservoir to transform a 100-year flood has not changed significantly. The reduction of the reservoir’s retention capacity should be systematically and regularly monitored in order to adjust its operational manual and improve its efficiency.

Waterfowl migration on Klamath Basin National Wildlife Refuges 1953-2001

Science.gov (United States)

Gilmer, David S.; Yee, Julie L.; Mauser, David M.; Hainline, James M.

2004-01-01

The Klamath Basin National Wildlife Refuge (NWR) complex, located in northeastern California and southern Oregon, is situated on a major Pacific Flyway migration corridor connecting waterfowl breeding grounds in the north with major wintering grounds in California and Mexico. The complex comprises five waterfowl refuges including Lower Klamath NWR, Tule Lake NWR, Upper Klamath NWR, Klamath Marsh NWR, and Clear Lake NWR, and one bald eagle refuge, Bear Valley NWR. Lower Klamath and Tule Lake NWRs are the largest refuges in the complex; historically, they supported some of the greatest autumn and spring concentrations of migrating waterfowl in North America. Starting in 1953, standardized waterfowl surveys from small aircraft have been conducted in autumn through spring. This report summarizes waterfowl migration activity (i.e., abundance, species composition, distribution on refuges, and chronology) over four time periods—the long-term (1953-2001), early (1953-76), recent (1977-2001), and the most recent (1998-2001)—to describe changing patterns of migration on Klamath Basin refuges from autumn 1953 to spring 2001.Over the long term, waterfowl abundance (birds per day) on the refuge complex averaged about 1.0 million in autumn and about 360,000 in spring. A record peak count of 5.8 million waterfowl was recorded September 24-25, 1958. Average abundance of autumn staging waterfowl for the refuge complex, after reaching record levels in the 1950s and early 1960s, began a decline that lasted until the 1980s. A gradual recovery occurred during the 1990s, but autumn abundance has not recovered to pre-1970 levels. In contrast to autumn, average spring abundance was generally lower in the early decades but has gradually increased through the 1990s, particularly on Lower Klamath NWR.Dabbling ducks represented an average of 68% of all waterfowl in autumn and 55% in spring for the long term. Northern pintail (Anas acuta) was dominant, representing 62% of all dabblers in

Use of brackish ground water resources for regional energy center development, Tularosa Basin, New Mexico: preliminary evaluation. Executive summary

International Nuclear Information System (INIS)

1977-03-01

The objective of this study was to develop an impact and suitability profile for the use of the Tularosa Basin in south-central New Mexico as the potential location of an energy center. Underyling the Tularosa Basin is an aquifer system containing perhaps 40 million acre-feet of fresh and slightly saline (1-3 g/l) water that is theoretically recoverable and could be used for cooling and other energy-related or industrial purposes, particularly if energy development projects in other areas of the state and region are delayed, impeded, or cancelled because of uncertain availability or accessibility of water. This preliminary investigation of the Tularosa Basin reveals no outstanding features that would discourage further detailed analysis and planning for an energy complex. A major program of exploratory drilling, well logging, and testing is needed to determine aquifer characteristics and factors affecting well design. Since industrial development in the basin will necessarily involve Federal, state, and private lands, any serious plan will require collaboration of Federal, state, and local authorities

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

Science.gov (United States)

Assefa, Yibeltal; Worku, Alemayehu; Wouters, Edwin; Koole, Olivier; Haile Mariam, Damen; Van Damme, Wim

2012-01-01

Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

Directory of Open Access Journals (Sweden)

Yibeltal Assefa

Full Text Available INTRODUCTION: Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. METHODS: Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. RESULTS: We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. CONCLUSION: The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

Grounding line processes on the Totten Glacier

Science.gov (United States)

Cook, S.; Watson, C. S.; Galton-Fenzi, B.; Peters, L. E.; Coleman, R.

2017-12-01

The Totten Glacier has been an area of recent interest due to its large drainage basin, much of which is grounded below sea level and has a history of large scale grounding line movement. Reports that warm water reaches the sub-ice shelf cavity have led to speculation that it could be vulnerable to future grounding line retreat. Over the Antarctic summer 2016/17 an array of 6 GPS and autonomous phase-sensitive radar (ApRES) units were deployed in the grounding zone of the Totten Glacier. These instruments measure changes in ice velocity and thickness which can be used to investigate both ice dynamics across the grounding line, and the interaction between ice and ocean in the subglacial cavity. Basal melt rates calculated from the ApRES units on floating ice range from 1 to 17 m/a. These values are significantly lower than previous estimates of basal melt rate produced by ocean modelling of the subglacial cavity. Meanwhile, GPS-derived velocity and elevation on the surface of the ice show a strong tidal signal, as does the vertical strain rate within the ice derived from internal layering from the ApRES instruments. These results demonstrate the significance of the complex grounding pattern of the Totten Glacier. The presence of re-grounding points has significant implications for the dynamics of the glacier and the ocean circulation within the subglacial cavity. We discuss what can be learned from our in situ measurements, and how they can be used to improve models of the glacier's future behaviour.

Studies of geology and hydrology in the Basin and Range province, southwestern United States, for isolation of high-level radioactive waste: characterization of the Sonoran region, California

International Nuclear Information System (INIS)

Bedinger, M.S.; Sargent, Kenneth A.; Langer, William H.

1989-01-01

The Sonoran region of California lies west of the Colorado River and adjoins the Mojave Desert on the west, Death Valley on the northwest, and the Salton trough on the south. The region is arid with annual precipitation ranging from less than 80 millimeters to as great as 250 millimeters in one mountain range; annual free-surface evaporation is as great as 2,500 millimeters. The characteristic basin and range topography of the region was caused by a mid-Tertiary period of intense crustal extension, accompanied by volcanic eruptions, clastic sedimentation, faulting, and tilting. Potential host media for isolation of high-level radioactive waste include granite and other coarsegrained plutonic rocks, ash-flow tuff, and basalt and basaltic andesite lava flows. Thick sections of the unsaturated zone in basin fill, intrusive, and volcanic rocks appear to have potential as host media. The region is bordered on the west by areas of relatively greater Quaternary faulting, vertical crustal uplift, and seismicity. The region has a few areas of Quaternary volcanic activity. Geothermal heat flows of 2.5 heat-flow units or greater and one earthquake of magnitude 6-7 have been recorded. The region includes topographically closed basins as well as basins that drain to the Colorado River. Dry lakes and playas occupy the closed basins. Ground-water recharge and surface runoff are small because of the small amount of precipitation and great potential evaporation. Natural ground-water discharge is by evaporation in the basin playas and by underflow to the Colorado River. Dissolved-solids concentration of ground water generally is less than 500 milligrams per liter, and much of it is of the sodium bicarbonate type. Ground water is saline in many of the playas, and chloride or sulfate is the predominant anion. Small tonnages of ore have been produced from numerous precious and fewer base-metal deposits. (author)

Tectonic evolution of the Tualatin basin, northwest Oregon, as revealed by inversion of gravity data

Science.gov (United States)

McPhee, Darcy K.; Langenheim, Victoria E.; Wells, Ray; Blakely, Richard J.

2014-01-01

The Tualatin basin, west of Portland (Oregon, USA), coincides with a 110 mGal gravity low along the Puget-Willamette lowland. New gravity measurements (n = 3000) reveal a three-dimensional (3-D) subsurface geometry suggesting early development as a fault-bounded pull-apart basin. A strong northwest-trending gravity gradient coincides with the Gales Creek fault, which forms the southwestern boundary of the Tualatin basin. Faults along the northeastern margin in the Portland Hills and the northeast-trending Sherwood fault along the southeastern basin margin are also associated with gravity gradients, but of smaller magnitude. The gravity low reflects the large density contrast between basin fill and the mafic crust of the Siletz terrane composing basement. Inversions of gravity data indicate that the Tualatin basin is ∼6 km deep, therefore 6 times deeper than the 1 km maximum depth of the Miocene Columba River Basalt Group (CRBG) in the basin, implying that the basin contains several kilometers of low-density pre-CRBG sediments and so formed primarily before the 15 Ma emplacement of the CRBG. The shape of the basin and the location of parallel, linear basin-bounding faults along the southwest and northeast margins suggest that the Tualatin basin originated as a pull-apart rhombochasm. Pre-CRBG extension in the Tualatin basin is consistent with an episode of late Eocene extension documented elsewhere in the Coast Ranges. The present fold and thrust geometry of the Tualatin basin, the result of Neogene compression, is superimposed on the ancestral pull-apart basin. The present 3-D basin geometry may imply stronger ground shaking along basin edges, particularly along the concealed northeast edge of the Tualatin basin beneath the greater Portland area.

Heat flow in Railroad Valley, Nevada and implications for geothermal resources in the south-central Great Basin

Science.gov (United States)

Williams, C.F.; Sass, J.H.

2006-01-01

The Great Basin is a province of high average heat flow (approximately 90 mW m-2), with higher values characteristic of some areas and relatively low heat flow (characteristic of an area in south-central Nevada known as the Eureka Low. There is hydrologie and thermal evidence that the Eureka Low results from a relatively shallow, hydrologically controlled heat sink associated with interbasin water flow in the Paleozoic carbonate aquifers. Evaluating this hypothesis and investigating the thermal state of the Eureka Low at depth is a high priority for the US Geological Survey as it prepares a new national geothermal resource assessment. Part of this investigation is focused on Railroad Valley, the site of the largest petroleum reservoirs in Nevada and one of the few locations within the Eureka Low with a known geothermal system. Temperature and thermal conductivity data have been acquired from wells in Railroad Valley in order to determine heat flow in the basin. The results reveal a complex interaction of cooling due to shallow ground-water flow, relatively low (49 to 76 mW m-2) conductive heat flow at depth in most of the basin, and high (up to 234 mW m-2) heat flow associated with the 125??C geothermal system that encompasses the Bacon Flat and Grant Canyon oil fields. The presence of the Railroad Valley geothermal resource within the Eureka Low may be reflect the absence of deep ground-water flow sweeping heat out of the basin. If true, this suggests that other areas in the carbonate aquifer province may contain deep geothermal resources that are masked by ground-water flow.

Site evaluation for U.S. Bureau of Mines experimental oil-shale mine, Piceance Creek basin, Rio Blanco County, Colorado

Science.gov (United States)

Ege, John R.; Leavesley, G.H.; Steele, G.S.; Weeks, J.B.

1978-01-01

The U.S. Geological Survey is cooperating with the U.S. Bureau of Mines in the selection of a site for a shaft and experimental mine to be constructed in the Piceance Creek basin, Rio Blanco County, Colo. The Piceance Creek basin, an asymmetric, northwest-trending large structural downwarp, is located approximately 40 km (25 mi) west of the town of Meeker in Rio Blanco County, Colo. The oil-shale, dawsonite, nahcolite, and halite deposits of the Piceance Creek basin occur in the lacustrine Green River Formation of Eocene age. In the basin the Green River Formation comprises three members. In ascending order, they are the Douglas Creek, the Garden Gulch, and the Parachute Creek Members, Four sites are presented for consideration and evaluated on geology and hydrology with respect to shale-oil economics. Evaluated criteria include: (1) stratigraphy, (2) size of site, (3) oil-shale yield, (4) representative quantities of the saline minerals dawsonite and nahcolite, which must be present with a minimum amount of halite, (5) thickness of a 'leached' saline zone, (6) geologic structure, (7) engineering characteristics of rock, (8) representative surface and ground-water conditions, with emphasis on waste disposal and dewatering, and (9) environmental considerations. Serious construction and support problems are anticipated in sinking a deep shaft in the Piceance Creek basin. The two major concerns will be dealing with incompetent rock and large inflow of saline ground water, particularly in the leached zone. Engineering support problems will include stabilizing and hardening the rock from which a certain amount of ground water has been removed. The relative suitability of the four potential oil-shale experimental shaft sites in the Piceance Creek basin has been considered on the basis of all available geologic, hydrologic, and engineering data; site 2 is preferred to sites 1, 3, and 4, The units in this report are presented in the form: metric (English). Both units of

Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

International Nuclear Information System (INIS)

Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

2010-01-01

Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had 125 I and 638 patients had 103 Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline α-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm 3 , 25-45 cm 3 , 3 ; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline α-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

EVALUATION OF WATER POLLUTION STATUS IN SIRET HYDROGRAPHICAL BASIN (SUCEAVA REGION DUE TO AGRICULTURAL ACTIVITIES

Directory of Open Access Journals (Sweden)

Carmen Zaharia

2014-06-01

Full Text Available The study presents data concerning the water pollution status of Siret hydrographical basin (i.e. surface and ground waters, lakes in Suceava County area (different controlling/monitoring sections due to agricultural productive activities, especially regarding some quality indicators (nitrogen-based nutrient concentrations evaluated for 2008. These data are recommending the necessity of continuous monitoring of water quality in the Siret River hydrographical basin, in all existing control sections, for identification of any pollution episodes, non-reported by polluters to the local environmental regulators.

Losing ground in mega-deltas: basin-scale response to existential threats to the Mekong Delta

Science.gov (United States)

Arias, M. E.; Kondolf, G. M.; Schmitt, R. J. P.; Carling, P. A.; Darby, S. E.; Bizzi, S.; Castelletti, A.; Cochrane, T. A.; Gibson, S.; Kummu, M.; Oeurng, C.; Rubin, Z.; Wild, T. B.

2017-12-01

The Mekong Delta is, in terms of the number of livelihoods it supports, its economic importance, and in its vulnerability to climate change and sinking lands, one of the world's critically threatened mega-deltas. Livelihoods depend on the mere existence of the delta, but also on ecosystem services provided by the delta's drainage basin spanning 795,000 km2 in six abutting countries. These ecosystem services include delivery of sand required to build delta land in the face of rising sea-levels and sediment bound nutrients, provision of spawning habitat for fish that are ultimately harvested in the delta, and hydrologic regulation driving the delta's unique flood-pulse regime. However, while the delta is mainly located in Vietnam, the basin of the Mekong River is shared among China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. In the context of the region's dynamic growth, individual countries are pushing their own development agendas, which include extensive dam building, in-channel sand mining, construction of dykes and canals, and groundwater pumping, all of which contribute to subsidence and erosion of the Delta. Our synthesis of recent research indicates that most of the Mekong's delta land will likely fall below sea-level by 2100 as result of these drivers, exacerbating the impacts of global climatic changes. In this context, local infrastructural projects and changes in land- and water-management may temporarily mitigate some negative effects, but do not address the existential threat to the delta as a whole. To prevent, or at least substantially postpone, the drowning of the Mekong Delta requires identification of the key drivers and immediate concerted management actions on the basin-scale to change the trajectory of subsidence and sediment deficit. A specific challenge is to find the institutional arrangements in this transnational context that could support the needed management changes and equitably distribute costs and impacts. The Mekong Delta is

Review of potential host rocks for radioactive wasste disposal in the southeast United States: Triassic basin subregion

International Nuclear Information System (INIS)

1980-10-01

Based on an evaluation of existing information, areas were identified within the Triassic basins of the southeastern United States with geologic properties considered favorable for containment of radioactive waste. The study region included both exposed and buried Triassic basins from Maryland to Georgia. These basins are long, narrow northeast-trending troughs filled with continental deposits derived from Paleozoic and Precambrian metamorphic and igneous rocks bordering the basins. The rocks are predominantly red in color and consist mainly of fanglomerates, conglomerates, arkosic sandstones, siltstones, claystones, shales, and argillites. The investigation identified 14 exposed and 5 buried basins within the study region. Candidate areas for further investigation were identified which meet the broad general criteria for tectonic stability, slow ground water movement, and long flow paths to the biosphere. These include: the Danville Triassic Basin in Virginia; the Dan River, Durham, and Wadesboro Triassic Basins in North Carolina; and the buried Florence and Dunbarton Triassic Basins in South Carolina. Other rock types in the southeast may prove more or less suitable as host rocks for a repository, but the available data suggest that the argillaceous Triassic rocks offer sufficient promise to be considered for additional study

Simulated Effects of Seasonal Ground-Water Pumpage for Irrigation on Hydrologic Conditions in the Lower Apalachicola-Chattahoochee-Flint River Basin, Southwestern Georgia and Parts of Alabama and Florida, 1999-2002

Science.gov (United States)

Jones, L. Elliott; Torak, Lynn J.

2006-01-01

To determine the effects of seasonal ground-water pumpage for irrigation, a finite-element ground-water flow model was developed for the Upper Floridan aquifer in the lower Flint River Basin area, including adjacent parts of the Chattahoochee and Apalachicola River Basins. The model simulates withdrawal from the aquifer at 3,280 irrigation, municipal, and industrial wells; stream-aquifer flow between the aquifer and 36 area streams; leakage to and from the overlying upper semiconfining unit; regional ground-water flow at the lateral boundaries of the model; and water-table recharge in areas where the aquifer is at or near land surface. Steady-state calibration to drought conditions of October 1999 indicated that the model could adequately simulate measured groundwater levels at 275 well locations and streamflow gains and losses along 53 reaches of area streams. A transient simulation having 12 monthly stress periods from March 2001 to February 2002 incorporated time-varying stress from irrigation pumpage, stream and lake stage, head in the overlying upper semiconfining unit, and infiltration rates. Analysis of simulated water budgets of the Upper Floridan aquifer provides estimates of the source of water pumped for irrigation. During October 1999, an estimated 127 million gallons per day (Mgal/d) of irrigation pumpage from the Upper Floridan aquifer in the model area were simulated to be derived from changes in: stream-aquifer flux (about 56 Mgal/d, or 44 percent); leakage to or from the upper semiconfining unit (about 49 Mgal/d, or 39 percent); regional flow (about 18 Mgal/d, or 14 percent); leakage to or from Lakes Seminole and Blackshear (about 2.7 Mgal/d, or 2 percent); and flux at the Upper Floridan aquifer updip boundary (about 1.8 Mgal/d, or 1 percent). During the 2001 growing season (May-August), estimated irrigation pumpage ranged from about 310 to 830 Mgal/ d, about 79 percent of the 12-month total. During the growing season, irrigation pumpage was

The effect of podcast lectures on nursing students' knowledge retention and application.

Science.gov (United States)

Abate, Karen S

2013-01-01

This pilot study sought to evaluate the effectiveness of academic podcasts in promoting knowledge retention and application in nursing students. Nursing education no longer simply occurs in a fixed location or time. Computer-enhanced mobile learning technologies, such as academic podcasts, must be grounded in pedagogically sound characteristics to ensure effective implementation and learning in nursing education. A convenience sample of 35 female undergraduate nursing students was randomized into three groups: a traditional face-to-face lecture group, an unsegmented (non-stop) podcast lecture group, and a segmented podcast lecture group. Retention and application of information were measured through a multiple-choice quiz and a case study based on lecture content. Students in the segmented podcast lecture group demonstrated higher scores on multiple-choice and case-study assessments than those in the other two groups. Nurse educators should be aware of this finding when seeking to employ podcast lectures in nursing education.

The inspection of a radiologically contaminated pipeline using a teleoperated pipe crawler

International Nuclear Information System (INIS)

Fogle, R.F.; Kuelske, K.; Kellner, R.A.

1995-01-01

In the 1950s, the Savannah River Site built an open, unlined retention basin to temporarily store potentially radionuclide contaminated cooling water from a chemical separations process and storm water drainage from a nearby waste management facility that stored large quantities of nuclear fission byproducts in carbon steel tanks. The retention basin was retired from service in 1972 when a new, lined basin was completed. In 1978, the old retention basin was excavated, backfilled with uncontaminated dirt, and covered with grass. At the same time, much of the underground process pipeline leading to the basin was abandoned. Since the closure of the retention basin, new environmental regulations require that the basin undergo further assessment to determine whether additional remediation is required. A visual and radiological inspection of the pipeline was necessary to aid in the remediation decision making process for the retention basin system. A teleoperated pipe crawler inspection system was developed to survey the abandoned sections of underground pipelines leading to the retired retention basin. This paper will describe the background to this project, the scope of the investigation, the equipment requirements, and the results of the pipeline inspection

Ground-water recharge in the arid and semiarid southwestern United States

Science.gov (United States)

Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground-water recharge in the arid and semiarid southwestern United States results from the complex interplay of climate, geology, and vegetation across widely ranging spatial and temporal scales. Present-day recharge tends to be narrowly focused in time and space. Widespread water-table declines accompanied agricultural development during the twentieth century, demonstrating that sustainable ground-water supplies are not guaranteed when part of the extracted resource represents paleorecharge. Climatic controls on ground-water recharge range from seasonal cycles of summer monsoonal and winter frontal storms to multimillennial cycles of glacial and interglacial periods. Precipitation patterns reflect global-scale interactions among the oceans, atmosphere, and continents. Large-scale climatic influences associated with El Niño and Pacific Decadal Oscillations strongly, but irregularly, control weather in the study area, so that year-to-year variations in precipitation and ground-water recharge are large and difficult to predict. Proxy data indicate geologically recent periods of naturally occurring multidecadal droughts unlike any in the modern instrumental record. Any anthropogenically induced climate change will likely reduce ground-water recharge through diminished snowpack at higher elevations. Future changes in El Niño and monsoonal patterns, both crucial to precipitation in the study area, are highly uncertain in current models. Current land-use modifications influence ground-water recharge through vegetation, irrigation, and impermeable area. High mountain ranges bounding the study area—the San Bernadino Mountains and Sierra Nevada to the west, and the Wasatch and southern Colorado Rocky Mountains to the east—provide external geologic controls on ground-water recharge. Internal geologic controls stem from tectonic processes that led to numerous, variably connected alluvial-filled basins, exposure of extensive Paleozoic aquifers in mountainous recharge

Wildlife habitats in managed rangelands—the Great Basin of southeastern Oregon: introduction.

Science.gov (United States)

Chris Maser; Jack Ward. Thomas

1983-01-01

The need for a way by which rangeland managers can account for wildlife in land-use planning, in on-the-ground management actions, and in preparation of environmental impact statements is discussed. Principles of range-land-wildlife interactions and management are described along with management systems. The Great Basin of southeastern Oregon was selected as a well-...

The MITMOTION Project - A seismic hazard overview of the Mitidja Basin (Northern Algeria)

Science.gov (United States)

Borges, José; Ouyed, Merzouk; Bezzeghoud, Mourad; Idres, Mouloud; Caldeira, Bento; Boughacha, Mohamed; Carvalho, João; Samai, Saddek; Fontiela, João; Aissa, Saoussen; Benfadda, Amar; Chimouni, Redouane; Yalaoui, Rafik; Dias, Rui

2017-04-01

The Mitidja Basin (MB) is located in northern Algeria and is filled by quaternary sediments with a length of about 100 km on the EW direction and approximately 20 km width. This basin is limited to the south by the Boumerdes - Larbaa - Blida active fault system and to the north by the Thenia - Sahel fault system. Both fault systems are of the reverse type with opposed dips and accommodate a general slip rate of 4 mm/year. This basin is associated with important seismic events that affected northern Algeria since the historical period until the present. The available earthquake catalogues reported numerous destructive earthquakes that struke different regions, such as Algiers (1365, Io= X; 1716, Io = X). Recently, on May 2003 the Bourmedes earthquake (Mw = 6.9) affected the area of Zemmouri and caused 2.271 deaths. The event was caused by the reactivation of the MB boundary faults. The epicenter was located offshore and generated a maximum uplift of 0.8 m along the coast with a horizontal maximum slip of 0.24 m. Recent studies show that the Boumerdes earthquake overloaded the system of adjacent faults with a stress increase between 0.4 and 1.5 bar. This induced an increase of the seismic hazard potential of the region and recommends a more detailed study of this fault system. The high seismogenic potential of the fault system bordering the MB, the exposure to danger of the most densely populated region of Algiers and the amplification effect caused by the basin are the motivation for this project proposal that will focus on the evaluation of the seismic hazard of the region. The general purpose of the project is to improve the seismic hazard assessment on the MB producing realistic predictions of strong ground motion caused by moderate and large earthquakes. To achieve this objective, it is important to make an effort in 3 directions: 1) the development of a detailed 3D velocity/structure model of the MB that includes geological constraints, seismic reflection data

Effect of urban stormwater runoff on ground water beneath recharge basins on Long Island, New York

Science.gov (United States)

Ku, H.F.; Simmons, D.L.

1986-01-01

Urban stormwater runoff was monitored during 1980-82 to investigate the source, type, quantity, and fate of contaminants routed to the more than 3,000 recharge basins on Long Island and to determine whether this runoff might be a significant source of contamination to the groundwater reservoir. Forty-six storms were monitored at five recharge basins in representative land use areas (strip commercial, shopping-mall parking lot, major highway, low-density residential, and medium-density residential). Runoff:precipitation ratios indicate that all storm runoff is derived from precipitation on impervious surfaces in the drainage area, except during storms of high intensity or long duration, when additional runoff can be derived from precipitation on permeable surfaces. Lead was present in highway runoff in concentrations up to 3300 micrograms/L, and chloride was found in parking lot runoff concentrations up to 1,100 mg/L during winter, when salt is used for deicing. In the five composite stormwater samples and nine groundwater grab samples that were analyzed for 113 EPA-designated ' priority pollutants, ' four constituents were detected in concentrations exceeding New York State guidelines of 50 micrograms/L for an individual organic compound in drinking water: p-chloro-m-cresol (79 micrograms/L); 2 ,4-dimethylphenol (96 micrograms/L); 4-nitrophenol (58 micrograms/L); and methylene chloride (230 micrograms/L in either groundwater or stormwater at the highway basin). One stormwater sample and two groundwater samples exceeded New York State guidelines for total organic compounds in drinking water (100 micrograms/L). The presence of these constituents is attributed to contamination from point sources rather than to the quality of runoff from urban areas. The median number of indicator bacteria in stormwater ranged from 0.1 to 10 billion MPN/100 ml. Fecal coliforms and fecal streptococci increased by 1 to 2 orders of magnitude during the warm season. The use of recharge

Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations

Science.gov (United States)

Hartzell, Stephen; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.

2016-01-01

Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response of the Livermore basin, a major structural depression in the California Coast Range Province bounded by active faults. Site response is calculated by two methods: the reference‐site spectral ratio method and a source‐site spectral inversion method. Longer‐period (≥1  s) amplification factors follow the same general pattern as Bouguer gravity anomaly contours. Site response spectra are inverted for shallow shear‐wave velocity profiles, which are consistent with independent information. Frequency–wavenumber analysis is used to analyze plane‐wave propagation across the Livermore Valley and to identify basin‐edge‐induced surface waves with back azimuths different from the source back azimuth. Finite‐element simulations in a 3D velocity model of the region illustrate the generation of basin‐edge‐induced surface waves and point out strips of elevated ground velocities along the margins of the basin.

Ground-state structures of Hafnium clusters

Energy Technology Data Exchange (ETDEWEB)

Ng, Wei Chun; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technoloty, Multimedia University, Melaca Campus, 75450 Melaka (Malaysia)

2015-04-24

Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.

A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

Science.gov (United States)

Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

2017-12-01

Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

Preliminary study of the uranium potential of the Triassic Sanford basin and Colon cross structure, North Carolina

International Nuclear Information System (INIS)

Lee, C.H.

1978-01-01

A preliminary geologic investigation was conducted to determine if Triassic sedimentary rocks of the Sanford basin and Colon cross structure in North Carolina are favorable hosts for uranium deposits. Rocks of adjacent Carolina slate belt were also examined as a potential source of uranium. On the basis of favorability criteria for sandstone-type uranium deposits, and geologic and geophysical investigations of the study area, the most favorable sites for further investigation are (1) at the contacts between the Pekin and Cumnock and between the Pekin and Sanford Formations near the Colon cross structure and (2) at the base of the Jonesboro fault, which lies below the Sanford Formation, northwest of Sanford. The highly weathered granites southeast of the Jonesboro fault were a source of the detritus deposited on the cross structure and may have been a primary source of uranium. Uranium leached from the coarse sediment (Pekin Formation) of the cross structure may have been transported downdip and may have been precipitated by the carbonaceous shales of the Cumnock Formation on the western side of the cross structure or at the Pekin-Sanford contact to the east. The Jonesboro fault may provide an impermeable barrier to ground-water migration in the metamorphosed basement rocks below the Triassic sediments. Such a barrier would constitute a favorable site for the precipitation and retention of uranium. Scintillometer surveys and laboratory analyses indicate no anomalous surface radioactivity in the study area. However, deep surface weathering may have caused the uranium to be leached from the exposed rocks and redeposited at depth. Geologic investigations show that conditions which have proven favorable for deposition of uranium in other areas are present in the Triassic rocks of the Sanford basin and Colon cross structure. However, because of deep surface weathering, further subsurface studies are necessary to confirm the favorability of the rocks as hosts for uranium

Short overview of water scarcity in the basins of the Upper Tietê River and PCJ

Directory of Open Access Journals (Sweden)

Luciana Cordeiro de Souza Fernandes

2015-12-01

Full Text Available Water scarcity in the region of the Alto Tietê basin and Piracicaba, Capivari and Jundiaí basins (PCJ, southeastern Brazil, it is a concrete fact that should be faced. In our view it is not a simple water crisis, but a water collapse a decade advertised, which shows an inconsistent and ineffective planning, a lack of political management and the flagrant absence of compliance with the legal grounds brought by the National Water Resources Policy Act (Federal Law n. 9433/97.

Urinary Retention Associated with Stroke.

Science.gov (United States)

Umemura, Takeru; Ohta, Hirotsugu; Yokota, Akira; Yarimizu, Shiroh; Nishizawa, Shigeru

Patients often exhibit urinary retention following a stroke. Various neuropathological and animal studies have implicated the medulla oblongata, pons, limbic system, frontal lobe as areas responsible for micturition control, although the exact area responsible for urinary retention after stroke is not clear. The purpose of this study was to identify the stroke area responsible for urinary retention by localizing the areas where strokes occur. We assessed 110 patients with cerebral infarction and 27 patients with cerebral hemorrhage (78 men, 59 women; mean age, 73.0 years) who had been admitted to our hospital between October, 2012 and September, 2013. We used computed tomography (CT) and magnetic resonance imaging (MRI) to investigate the stroke location, and evaluated whether post-stroke urinary retention occurred. Twelve (8.8%) of the 137 patients (7 men, 5 women; mean age, 78.8 years) exhibited urinary retention after a stroke. Stroke occurred in the right/left dominant hemisphere in 7 patients; nondominant hemisphere in 1; cerebellum in 3; and brainstem in 1. Strokes in the dominant hemisphere were associated with urinary retention (P = 0.0314), particularly in the area of the insula (P < 0.01). We concluded that stroke affecting the insula of the dominant hemisphere tends to cause urinary retention.

Effect of dietary coarsely ground corn on broiler live performance, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and digesta particle size distribution and retention time.

Science.gov (United States)

Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Pacheco, W J; Brake, J

2015-01-01

Dietary structural material has been reported to improve broiler live performance and gastrointestinal tract (GIT) function. In this 50 d cage study, the effects of coarsely ground corn (CC) inclusion on broiler live performance, GIT development, apparent ileal digestibility (AID) of energy and nitrogen (N), and digesta particle size distribution and retention time were investigated. This study included 3 CC inclusions (0, 25, and 50% fine corn [FC] replaced by CC), with 6 replicate cages of 10 birds per treatment. The feed conversion ratio (FCR) at 35 and 42 d was improved (P<0.01) as the dietary inclusion of CC increased without effect on feed intake. The 50% CC diet increased absolute and relative gizzard weight at 42 d of age as compared to diets with 0 and 25% CC (P<0.01). Dietary CC increased absolute proventriculus weight at 28 d of age (P<0.05). A numerically lower gizzard digesta pH (P<0.08) was observed at 28 d but not 42 d of age, and there was no difference in proventriculus, jejunum, or ileum digesta pH at 28 or 42 d of age. The 25 and 50% CC treatments increased the digesta retention time at 30 and 45 d of age (P<0.05 and P<0.01, respectively). The 25 and 50% CC treatments improved AID of energy by 7.1 and 8.2%, respectively, when compared with the 0% CC treatment, and they improved AID of N by 12.2 and 12.4%, respectively (P<0.01). The digesta particles in the jejunum exhibited a similar distribution, with a dgw (geometric mean diameter by mass) of 218, 204, and 181 μm when 0, 25, of 50% CC diets were consumed, respectively. In conclusion, birds fed pelleted and screened diets that contained 25 and 50% CC exhibited increased BW, improved FCR, and increased AID of energy and N, which was probably due to enhanced gizzard development and greater digesta retention time. © The Author 2015. Published by Oxford University Press on behalf of Poultry Science Association.

Modeling Effects of Groundwater Basin Closure, and Reversal of Closure, on Groundwater Quality

Science.gov (United States)

Pauloo, R.; Guo, Z.; Fogg, G. E.

2017-12-01

Population growth, the expansion of agriculture, and climate uncertainties have accelerated groundwater pumping and overdraft in aquifers worldwide. In many agricultural basins, a water budget may be stable or not in overdraft, yet disconnected ground and surface water bodies can contribute to the formation of a "closed" basin, where water principally exits the basin as evapotranspiration. Although decreasing water quality associated with increases in Total Dissolved Solids (TDS) have been documented in aquifers across the United States in the past half century, connections between water quality declines and significant changes in hydrologic budgets leading to closed basin formation remain poorly understood. Preliminary results from an analysis with a regional-scale mixing model of the Tulare Lake Basin in California indicate that groundwater salinization resulting from open to closed basin conversion can operate on a decades-to-century long time scale. The only way to reverse groundwater salinization caused by basin closure is to refill the basin and change the hydrologic budget sufficiently for natural groundwater discharge to resume. 3D flow and transport modeling, including the effects of heterogeneity based on a hydrostratigraphic facies model, is used to explore rates and time scales of groundwater salinization and its reversal under different water and land management scenarios. The modeling is also used to ascertain the extent to which local and regional heterogeneity need to be included in order to appropriately upscale the advection-dispersion equation in a basin scale groundwater quality management model. Results imply that persistent managed aquifer recharge may slow groundwater salinization, and complete reversal may be possible at sufficiently high water tables.

Geology, Streamflow, and Water Chemistry of the Talufofo Stream Basin, Saipan, Northern Mariana Islands

Science.gov (United States)

Izuka, Scot K.; Ewart, Charles J.

1995-01-01

A study of the geology, streamflow, and water chemistry of Talufofo Stream Basin, Saipan, Commonwealth of the Northern Mariana Islands, was undertaken to determine the flow characteristics of Talufofo Stream and the relation to the geology of the drainage basin. The Commonwealth government is exploring the feasibility of using water from Talufofo Stream to supplement Saipan's stressed municipal water supply. Streamflow records from gaging stations on the principal forks of Talufofo Stream indicate that peak streamflows and long-term average flow are higher at the South Fork gaging station than at the Middle Fork gaging station because the drainage area of the South Fork gaging station is larger, but persistent base flow from ground-water discharge during dry weather is greater in the Middle Fork gaging station. The sum of the average flows at the Middle Fork and South Fork gaging stations, plus an estimate of the average flow at a point in the lower reaches of the North Fork, is about 2.96 cubic feet per second or 1.91 million gallons per day. Although this average represents the theoretical maximum long-term draft rate possible from the Talufofo Stream Basin if an adequate reservoir can be built, the actual amount of surface water available will be less because of evaporation, leaks, induced infiltration, and reservoir-design constraints. Base-flow characteristics, such as stream seepage and spring discharge, are related to geology of the basin. Base flow in the Talufofo Stream Basin originates as discharge from springs near the base of limestones located in the headwaters of Talufofo Stream, flows over low-permeability volcanic rocks in the middle reaches, and seeps back into the high-permeability limestones in the lower reaches. Water sampled from Talufofo Stream during base flow had high dissolved-calcium concentrations (between 35 and 98 milligrams per liter), characteristic of water from a limestone aquifer. Concentrations of potassium, sodium, and chloride

Hydrochemical and isotopic studies of ground water from Botucatu Aquifer - Partial results for North region of Parana Basin

International Nuclear Information System (INIS)

Silva, R.B.G. da; Kimmelmann, A.A.; Cunha Reboucas, A. da

1985-01-01

The first results of an investigation, to study the flow path, the processes controlling the chemical composition, the recharge, as well as, the origin, apparent ages and dynamic of the groundwater of the Botucatu Aquifer in the Brazilian part of the Parana Basin (818.000 Km 2 ), using hydrochemical and environmental isotope technics ( 2 H, 18 O, 13 C, 3 H, 14 C), are presented. Samples of 20 deep wells, located in the northern part of the Basin (states of Sao Paulo, Mato Grosso do Sul and Goias), were analysed. (Author) [pt

Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

Science.gov (United States)

Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

2017-10-01

Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case

Does skill retention benefit from retentivity and symbolic rehearsal? - two studies with a simulated process control task.

Science.gov (United States)

Kluge, Annette; Frank, Barbara; Maafi, Sanaz; Kuzmanovska, Aleksandra

2016-05-01

Two experiments were designed to compare two symbolic rehearsal refresher interventions (imaginary practice, a hidden introspective process) and investigate the role of retentivity in skill retention. Retentivity is investigated as the ability to memorise and reproduce information and associations that were learned a short time ago. Both experiments comprised initial training (week 1), a symbolic rehearsal for the experimental group (week 2) and a retention assessment (week 3). In the first study, the experimental group received a symbolic rehearsal, while the control group received no rehearsal. In the second study, the experimental group received the same symbolic rehearsal used in study 1, enhanced with rehearsal tasks addressing human-computer interaction. The results showed that both symbolic rehearsal interventions were equally likely to mitigate skill decay. The retentivity showed medium to high correlations with skill retention in both studies, and the results suggest that subjects high in retentivity benefit more from a symbolic rehearsal refresher intervention. Practitioner Summary: Skill decay becomes a problem in situations in which jobs require the correct mastery of non-routine situations. Two experimental studies with simulated process control tasks showed that symbolic rehearsal and retentivity can significantly mitigate skill decay and that subjects higher in retentivity benefit more from refresher interventions.

Factors controlling As and U in shallow ground water, southern Carson Desert, Nevada

Science.gov (United States)

Welch, A.H.; Lico, M.S.

1998-01-01

Unusually high As and U concentrations (> 100 ??g/L) are widespread in shallow ground water beneath the southern Carson Desert. The high concentrations, which locally exceed 1000 ??g/L, are of concern from a human health standpoint because the shallow ground water is used for domestic supply. Possible affects on wildlife are also of concern because the ground water flows into shallow lakes and marshes within wildlife refuges. Arsenic and U concentrations in ground water of the southern Carson Desert appear to be affected by evaporative concentration, redox reactions, and adsorption. The relation of these elements with Cl suggest that most of the high concentrations can be attributed to evaporative concentration of Carson River water, the primary source of recharge. Some ground water contains higher As and U concentrations that cannot be explained by evaporative concentration alone. Oxidation-reduction reactions, involving metal oxides and sedimentary-organic matter, appear to contribute As, U, inorganic C, Fe and Mn to the ground water. Arsenic in Fe-oxide was confirmed by chemical extraction and is consistent with laboratory adsorption studies. Uranium in both sedimentary-organic C and Fe-oxide coatings has been confirmed by fission tracks and petrographic examination. Arsenic concentrations in the ground water and chemical extracts of aquifer sediments are broadly consistent with adsorption as a control on some dissolved As concentrations. An apparent loss of As from some ground water as evaporative concentration proceeds is consistent with adsorption as a control on As. However, evidence for adsorption should be viewed with caution, because the adsorption model used values for the adsorbent that have not been shown to be valid for the aquifer sediments throughout the southern Carson Desert. Hydrologic and geochemical conditions in the Carson Desert are similar to other areas with high As and U concentrations in ground water, including the Salton Sea basin and

Factors controlling As and U in shallow ground water, southern Carson Desert, Nevada

International Nuclear Information System (INIS)

Lico, M.S.; Welch, A.H.

1998-01-01

100 μg/L) are widespread in shallow ground water beneath the southern Carson Desert. The high concentrations, which locally exceed 1000 μg/L, are of concern from a human health standpoint because the shallow ground water is used for domestic supply. Possible affects on wildlife are also of concern because the ground water flows into shallow lakes and marshes within wildlife refuges. Arsenic and U concentrations in ground water of the southern Carson Desert appear to be affected by evaporative concentration, redox reactions, and adsorption. The relation of these elements with Cl suggest that most of the high concentrations can be attributed to evaporative concentration of Carson River water, the primary source of recharge.Some ground water contains higher As and U concentrations that cannot be explained by evaporative concentration alone. Oxidation-reduction reactions, involving metal oxides and sedimentary-organic matter, appear to contribute As, U, inorganic C, Fe and Mn to the ground water. Arsenic in Fe-oxide was confirmed by chemical extraction and is consistent with laboratory adsorption studies. Uranium in both sedimentary-organic C and Fe-oxide coatings has been confirmed by fission tracks and petrographic examination.Arsenic concentrations in the ground water and chemical extracts of aquifer sediments are broadly consistent with adsorption as a control on some dissolved As concentrations. An apparent loss of As from some ground water as evaporative concentration proceeds is consistent with adsorption as a control on As. However, evidence for adsorption should be viewed with caution, because the adsorption model used values for the adsorbent that have not been shown to be valid for the aquifer sediments throughout the southern Carson Desert.Hydrologic and geochemical conditions in the Carson Desert are similar to other areas with high As and U concentrations in ground water, including the Salton Sea basin and southern San Joaquin Valley of California

The Use of Grounded Theory to Develop a Framework for Understanding Student Retention in Community College Nursing Programs

Science.gov (United States)

Priode, Kimberly S.

2013-01-01

Gaining admission into pre-licensure nursing programs has proven to be quite difficult for the average college student. Topping the list of crucial priorities for many academic institutions is the retention of these nursing students. Yet, the reality is that many students decide not to complete their course of study for reasons other than academic…

Facies Analysis of Tertiary Basin-Filling Rocks of the Death Valley Regional Ground-Water System and Surrounding Areas, Nevada and California; TOPICAL

International Nuclear Information System (INIS)

Sweetkind, D.S.; Fridrich, C.J.; Taylor, Emily

2002-01-01

Existing hydrologic models of the Death Valley region typically have defined the Cenozoic basins as those areas that are covered by recent surficial deposits, and have treated the basin-fill deposits that are concealed under alluvium as a single unit with uniform hydrologic properties throughout the region, and with depth. Although this latter generalization was known to be flawed, it evidently was made because available geologic syntheses did not provide the basis for a more detailed characterization. As an initial attempt to address this problem, this report presents a compilation and synthesis of existing and new surface and subsurface data on the lithologic variations between and within the Cenozoic basin fills of this region. The most permeable lithologies in the Cenozoic basin fills are freshwater limestones, unaltered densely welded tuffs, and little-consolidated coarse alluvium. The least permeable lithologies are playa claystones, altered nonwelded tuffs, and tuffaceous and cl ay-matrix sediments of several types. In all but the youngest of the basin fills, permeability probably decreases strongly with depth owing to a typically increasing abundance of volcanic ash or clay in the matrices of the clastic sediments with increasing age (and therefore with increasing depth in general), and to increasing consolidation and alteration (both hydrothermal and diagenetic) with increasing depth and age. This report concludes with a categorization of the Cenozoic basins of the Death Valley region according to the predominant lithologies in the different basin fills and presents qualitative constraints on the hydrologic properties of these major lithologic categories

Military Retention. A Comparative Outlook

Directory of Open Access Journals (Sweden)

Vasile Sminchise

2016-06-01

Full Text Available One of the main goals for human resources management structures and for armed forces leaders is to maintain all necessary personnel, both qualitatively and quantitatively for operational needs or for full required capabilities. The retention of military personnel is essential to keep morale and unit readiness and to reduce the costs for recruiting, training, replacement of manpower. Retention rates depend not only on money or other social measures. The goal for retention is to keep in use the most valuable resource that belongs to an organization: the human beings and their knowledge. The aim pf this paper is to provide a comparative analysis of retention measures in various countries based on Research and Technology Organisation report released in 2007 and, thus, provide more examples of retention measures as far as the Romanian military system is concerned.

Retention of Root Canal Posts

DEFF Research Database (Denmark)

Sahafi, A; Benetti, Ana Raquel; Flury, S

2015-01-01

The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement......, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention...

Sensitivity analysis of a sediment dynamics model applied in a Mediterranean river basin: global change and management implications.

Science.gov (United States)

Sánchez-Canales, M; López-Benito, A; Acuña, V; Ziv, G; Hamel, P; Chaplin-Kramer, R; Elorza, F J

2015-01-01

Climate change and land-use change are major factors influencing sediment dynamics. Models can be used to better understand sediment production and retention by the landscape, although their interpretation is limited by large uncertainties, including model parameter uncertainties. The uncertainties related to parameter selection may be significant and need to be quantified to improve model interpretation for watershed management. In this study, we performed a sensitivity analysis of the InVEST (Integrated Valuation of Environmental Services and Tradeoffs) sediment retention model in order to determine which model parameters had the greatest influence on model outputs, and therefore require special attention during calibration. The estimation of the sediment loads in this model is based on the Universal Soil Loss Equation (USLE). The sensitivity analysis was performed in the Llobregat basin (NE Iberian Peninsula) for exported and retained sediment, which support two different ecosystem service benefits (avoided reservoir sedimentation and improved water quality). Our analysis identified the model parameters related to the natural environment as the most influential for sediment export and retention. Accordingly, small changes in variables such as the magnitude and frequency of extreme rainfall events could cause major changes in sediment dynamics, demonstrating the sensitivity of these dynamics to climate change in Mediterranean basins. Parameters directly related to human activities and decisions (such as cover management factor, C) were also influential, especially for sediment exported. The importance of these human-related parameters in the sediment export process suggests that mitigation measures have the potential to at least partially ameliorate climate-change driven changes in sediment exportation. Copyright © 2014 Elsevier B.V. All rights reserved.

Job embeddedness and nurse retention.

Science.gov (United States)

Reitz, O Ed; Anderson, Mary Ann; Hill, Pamela D

2010-01-01

Nurse retention is a different way of conceptualizing the employer-employee relationship when compared with turnover. Job embeddedness (JE), a construct based on retention, represents the sum of reasons why employees remain at their jobs. However, JE has not been investigated in relation to locale (urban or rural) or exclusively with a sample of registered nurses (RNs). The purpose of this study was to determine what factors (JE, age, gender, locale, and income) help predict nurse retention. A cross-sectional mailed survey design was used with RNs in different locales (urban or rural). Job embeddedness was measured by the score on the composite, standardized instrument. Nurse retention was measured by self-report items concerning intent to stay. A response rate of 49.3% was obtained. The typical respondent was female (96.1%), white, non-Hispanic (87.4%), and married (74.9%). Age and JE were predictive of nurse retention and accounted for 26% of the explained variance in intent to stay. Although age was a significant predictor of intent to stay, it accounted for only 1.4% of the variance while JE accounted for 24.6% of the variance of nurse retention (as measured by intent to stay). Older, more "embedded" nurses are more likely to remain employed in their current organization. Based on these findings, JE may form the basis for the development of an effective nurse retention program.

Water resources of the Blackstone River basin, Massachusetts

Science.gov (United States)

Izbicki, John A.

2000-01-01

By 2020, demand for water in the Blackstone River Basin is expected to be 52 million gallons per day, one-third greater than the demand of 39 million gallons per day in 1980. Most of this increase is expected to be supplied by increased withdrawals of ground water from stratified-drift aquifers in the eastern and northern parts of the basin. Increased withdrawals from stratified-drift aquifers along the Blackstone River and in the western part of the basin also are expected.The eastern and northern parts of the Blackstone River Basin contain numerous small, discontinuous aquifers which, as a group, comprise the largest ground-water resource of the study area. Fifteen aquifers, ranging in areal extent from 0.57 to 4.3 square miles, were identified. These aquifers have maximum saturated thicknesses ranging from less than 10 feet to 105 feet and maximum transmissivities ranging from less than 1,000 to more than 20,000 feet squared per day. Yields of nine study aquifers were estimated by use of digital ground-water-flow models. Yields depend on the hydraulic properties of the aquifer and the amount of streamflow available for depletion by wells. If streamflow is maintained at 98-percent duration, long-term yields from the aquifers that would be expected to be equaled or exceeded 50 percent of the time range from 0.22 to 11 million gallons per day, and long-term yields equaled or exceeded 95 percent of the time range from 0.06 to 1.0 million gallons per day. If streamflow is maintained at 99.5-percent duration, long-term yields equaled or exceeded 50 percent of the time range from 0.22 to 11 million gallons per day, long-term yields equaled or exceeded 95 percent of the time range from 0.04 to 1.4 million gallons per day, and longterm yields equaled or exceeded 98 percent of the time range from 0.02 to 0.39 million gallons per day. Maintaining streamflow at 98-percent duration is a more restrictive criterion than maintaining streamflow at 99.5-percent duration. The

Calculation of retention time tolerance windows with absolute confidence from shared liquid chromatographic retention data.

Science.gov (United States)

Boswell, Paul G; Abate-Pella, Daniel; Hewitt, Joshua T

2015-09-18

Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user's system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called "retention projection" was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. Copyright © 2015 Elsevier B.V. All rights reserved.

Geology and coal-bed methane resources of the northern San Juan Basin, Colorado and New Mexico

International Nuclear Information System (INIS)

Fassett, J.E.

1988-01-01

This guidebook is the first of its kind: A focused look at coal-bed methane in a large Rocky Mountain Laramide basin. The papers in this volume cover every aspect of coal-bed methane in the San Juan Basin, including: The geology, environments of deposition, and geometry of the coal beds that contain the resource; the origin and migration history of the gas; basin-wide resource estimates; the engineering aspects of getting the gas out of the ground; the marketing and economics of producing coal-bed methane in the San Juan Basin; the legal ownership of the gas; state regulations governing well spacing and field rules; disposal of produced water; and land and mineral ownership patterns in the northern part of the basin. Also included are detailed papers on all of the major coal-bed methane fields in the basin, and in a paper on the history of Fruitland gas production, a discussion of most of the not-so-major fields. A small section of the book deals with geophysical methods, as yet still experimental, for surface detection of underground hydrocarbon resources. Individual papers have been processed separately for inclusion on the data base

SEDIMENTATION AND BASIN-FILL HISTORY OF THE PLIOCENE SUCCESSION EXPOSED IN THE NORTHERN SIENA-RADICOFANI BASIN (TUSCANY, ITALY: A SEQUENCE-STRATIGRAPHIC APPROACH

Directory of Open Access Journals (Sweden)

IVAN MARTINI

2017-08-01

Full Text Available Basin-margin paralic deposits are sensitive indicators of relative sea-level changes and typically show complex stratigraphic architectures that only a facies-based sequence-stratigraphic approach, supported by detailed biostratigraphic data, can help unravel, thus providing constraints for the tectono-stratigraphic reconstructions of ancient basins. This paper presents a detailed facies analysis of Pliocene strata exposed in a marginal key-area of the northern Siena-Radicofani Basin (Tuscany, Italy, which is used as a ground for a new sequence-stratigraphic scheme of the studied area. The study reveals a more complex sedimentary history than that inferred from the recent geological maps produced as part of the Regional Cartographic Project (CARG, which are based on lithostratigraphic principles. Specifically, four sequences (S1 to S4, in upward stratigraphic order have been recognised, each bounded by erosional unconformities and deposited within the Zanclean-early Gelasian time span. Each sequence typically comprises fluvial to open marine facies, with deposits of different sequences that show striking lithological similarities.The architecture and internal variability shown by the studied depositional sequences are typical of low-accommodation basin-margin settings, that shows: i a poorly-developed to missing record of the falling-stage systems tract; ii a lowstand system tract predominantly made of fluvio-deltaic deposits; iii a highstand system tract with substantial thickness variation between different sequences due to erosional processes associated with the overlying unconformity; iv a highly variable transgressive system tract, ranging from elementary to parasequential organization.

Geochemistry and hydrodynamics of the Paradox Basin region, Utah, Colorado and New Mexico

Science.gov (United States)

Hanshaw, B.B.; Hill, G.A.

1969-01-01

The Paradox Basin region is approximately bounded by the south flank of the Uinta Basin to the north, the Uncompahgre uplift and San Juan Mountains to the east, the Four Corners structural platform to the southeast, the north rim of the Black Mesa Basin and the Grand Canyon to the south and southwest, and the Wasatch Plateau and Hurricane fault system to the west. Some of these geologic features are areas of ground-water recharge or discharge whereas others such as the Four Corners platform do not directly influence fluid movement. The aquifer systems studied were: (1) Mississippian rocks; (2) Pinkerton Trail Limestone of Wengerd and Strickland, 1954; (3) Paradox Member of the Hermosa Formation; (4) Honaker Trail Formation of Wengerd and Matheny, 1958; (5) Permian rocks. Recharge in the Paradox Basin occurs on the west flank of the San Juan Mountains and along the west side of the Uncompahgre uplift. The direction of ground-water movement in each analyzed unit is principally southwest-ward toward the topographically low outcrop areas along the Colorado River in Arizona. However, at any point in the basin, flow may be in some other direction owing to the influence of intrabasin recharge areas or local obstructions to flow, such as faults or dikes. A series of potentiometric surface maps was prepared for the five systems studied. Material used in construction of the maps included outcrop altitudes of springs and streams, drill-stem tests, water-well records, and an electric analog model of the entire basin. Many structurally and topographically high areas within the basin are above the regional potentiometric surface; recharge in these areas will drain rapidly off the high areas and adjust to the regional water level. With a few exceptions, most wells in formations above the Pennsylvanian contain fresh ( 35,000 mg/l T.D.S.) reported. Most water samples from strata below the Permian are brines of the sodium chloride type but with large amounts of calcium sulfate or

Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River

Directory of Open Access Journals (Sweden)

W. Santini

2015-03-01

Full Text Available Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted during Neogene times by a still active sub-Andean tectonic thrust. Around 40% of those sediments are trapped in the Ucayali retro-foreland basin system. Recent advances in remote sensing for Amazonian large rivers now allow us to complete the ground hydrological data. In this work, we propose a first estimation of the erosion and sedimentation budget of the Ucayali River catchment, based on spatial and conventional HYBAM Observatory network.

Hydrogeology, geochemistry, and quality of water of The Basin and Oak Spring areas of the Chisos Mountains, Big Bend National Park, Texas

Science.gov (United States)

Baker, E.T.; Buszka, P.M.

1993-01-01

Test drilling near two sewage lagoons in The Basin area of the Chisos Mountains, Big Bend National Park, Texas, has shown that the alluvium and colluvium on which the lagoons are located is not saturated in the immediate vicinity of the lagoons. A shallow aquifer, therefore, does not exist in this critical area at and near the lagoons. Should seepage outflow from the lagoons occur, the effluent from the lagoons might eventually be incorporated into shallow ground water moving westward in the direction of Oak Spring. Under these conditions such water could reach the spring. Test borings that bottomed in bedrock below the alluvial and colluvial fill material are dry, indicating that no substantial leakage from the lagoons was detected. Therefore, no contaminant plume was identified. Fill material in The Basin does not contain water everywhere in its extensive outcropping area and supplies only a small quantity of ground water to Window Pouroff, which is the only natural surface outlet of The Basin.

Use of environmental isotope tracer and GIS techniques to estimate basin recharge

Science.gov (United States)

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

Conceptual plan for 100-N Emergency Dump Basin (EDB) deactivation

International Nuclear Information System (INIS)

Davis, C.M.; Day, R.S.; Smith, D.L.

1996-07-01

This document provides the conceptual plan for the 100-N Emergency Dump Basin (EDB) located at the Hanford Site in Richland, Washington. The EDB is an outdoor concrete retention pond with a carbon-steel liner underlain with fiberglass. The EDB was originally designed as a quenching pool for reactor blowdown in event of a primary coolant leak. However, the EDB only received routine steam-generator blowdowns from 1963 to 1987. The steam-generator blowdown and leaking isolation valves allowed radioactively contaminated water (from primary and secondary reactor coolant leaks) to enter the EDB. Over the years, wind-blown sand and dust have settled in the EDB, resulting in the present layer of sediments. As of February 1996, the EDB contained an estimated 260,000 gal of water and approximately 2,300 ft3 of sediment. The average sediment thickness is estimated at 2.5 ft and is covered with approximately 12 ft to 14 ft of water. Vegetation (mostly reeds and cattails) grows in the basin corners where the sediment is exposed. To minimize animal and bird intrusion, a kneeling net has been installed over the EDB

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

Energy Technology Data Exchange (ETDEWEB)

Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D; Petersson, N A; Larsen, S C; Ma, S; Jachens, R C

2009-11-04

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the Next Generation Attenuation (NGA) ground-motion prediction equations. We attribute at least some of this difference to the relatively narrow width of the Hayward fault ruptures. The simulations suggest that the Spudich and Chiou (2008) directivity corrections to the NGA relations could be improved by including a dependence on the rupture speed and increasing the areal extent of rupture directivity with period. The simulations also indicate that the NGA relations may under-predict amplification in shallow sedimentary basins.

Urinary retention in women

African Journals Online (AJOL)

Urinary retention in women. Urinary retention in women is often transient and of no known cause. ... stones, constipation, urethral cancer, uterine fibroids ... present with abnormal bladder function secondary to ... (CT), magnetic resonance imaging (MRI) or myelography ... full blood count, urea, electrolytes and creatinine can ...

Isotope techniques in hydrological studies: application to Chacabuco-Polpaico basin

International Nuclear Information System (INIS)

Orphanopoulus Stehr, D.

1982-01-01

A hydrogeological study was carried out in a small alluvial valley, 45 kms. north of Santiago, Chile. Although the main economical activity is the agriculture, the valley only has small seasonal rivers. The irrigation water comes from a near basin through a channel of about 100 kms. and from the ground water. The study include aspects like: pumping tests evaluations, well stratigraphy, potentiometric surface fluctuation, water chemistry, stable isotopes and water balances. Isotopes, oxygen-18 and deuterium were used to identify the origin of the ground water in different sections of the valley and the importance of the infiltration. Also experiences were made to evaluate the evaporation of a small damm, using isotopes and the classical water balance methods. (O.S.)

Groundwater Levels for Selected Wells in the Chehalis River Basin, Washington

Science.gov (United States)

Fasser, E.T.; Julich, R.J.

2010-01-01

Groundwater levels for selected wells in the Chehalis River basin, Washington, are presented on an interactive web-based map to document the spatial distribution of groundwater levels in the study area during late summer 2009. Groundwater level data and well information were collected by the U.S. Geological Survey using standard techniques. The data are stored in the USGS National Water Information System (NWIS), Ground-Water Site-Inventory (GWSI) System.

Preserved Crevasse Casts in the Whales Deep Basin, eastern Ross Sea

Science.gov (United States)

Bart, P. J.; Tulaczyk, S. M.

2017-12-01

A recent seismic stratigraphic study showed that the large bathymetric saddle in the Whales Deep Basin in eastern Ross Sea is a compound grounding zone wedge (CGZW). The basin was occupied by the paleo Bindschadler Ice Stream when grounded ice advanced to the outer continental shelf during the last glacial maximum (LGM). The CGZW is composed of at least seven overlapping GZWs. The crest of the bathymetric saddle corresponds to the grounding zone of GZW7, i.e., the seventh GZW. The north face of the saddle is essentially equivalent to the GZW7 foreset and the south side of the saddle is the GZW7 topset, i.e., the seafloor surface to which the paleo Bindschadler Ice Stream was grounded. The GZW7 topset is mantled by a series of relatively small-amplitude, but very long, ridges with low sinuosity. These ridges were previously imaged by Mosola and Anderson (2006). Here we show a larger-area multibeam survey that was acquired in 2015 during expedition NBP1502B. The larger-area multibeam survey shows that the ridges have amplitudes ranging from 2 to 11 m above grade and have an overall northeast-southwest orientation over an area of at least 500 km2 on the central and western flank of Whales Deep Basin middle continental shelf in water depths ranging from 500 to 550 m. The ridges have spacing that mostly range between 1 and 2 km. The longest ridges are observed to be 40 km. The ridges in the center of the trough have flatter tops than those in the shallower water on the flank of Houtz Bank. In our ongoing investigation of these interesting features, we hypothesize that the ridges formed below a rapidly flowing ice stream as it thinned and was decoupling from the bed towards the end of GZW7 deposition. High ice deformation rates accompanying this process caused the development of large basal crevasses or ice shelf rifts that reached the seafloor. Subglacial till was scraped and collected into lower parts of these crevasses/rifts. Chronologic data indicates that these

High-resolution digital elevation model of Mount St. Helens crater and upper North Fork Toutle River basin, Washington, based on an airborne lidar survey of September 2009

Science.gov (United States)

Mosbrucker, Adam

2014-01-01

The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980–1986 and 2004–2008. More than three decades after the emplacement of the 1980 debris avalanche, high sediment production persists in the North Fork Toutle River basin, which drains the northern flank of the volcano. Because this sediment increases the risk of flooding to downstream communities on the Toutle and Cowlitz Rivers, the U.S. Army Corps of Engineers (USACE), under the direction of Congress to maintain an authorized level of flood protection, built a sediment retention structure on the North Fork Toutle River in 1989 to help reduce this risk and to prevent sediment from clogging the shipping channel of the Columbia River. From September 16–20, 2009, Watershed Sciences, Inc., under contract to USACE, collected high-precision airborne lidar (light detection and ranging) data that cover 214 square kilometers (83 square miles) of Mount St. Helens and the upper North Fork Toutle River basin from the sediment retention structure to the volcano's crater. These data provide a digital dataset of the ground surface, including beneath forest cover. Such remotely sensed data can be used to develop sediment budgets and models of sediment erosion, transport, and deposition. The U.S. Geological Survey (USGS) used these lidar data to develop digital elevation models (DEMs) of the study area. DEMs are fundamental to monitoring natural hazards and studying volcanic landforms, fluvial and glacial geomorphology, and surface geology. Watershed Sciences, Inc., provided files in the LASer (LAS) format containing laser returns that had been filtered, classified, and georeferenced. The USGS produced a hydro-flattened DEM from ground-classified points at Castle, Coldwater, and Spirit Lakes. Final results averaged about five laser last

Transboundary water issues: The Ganga-Brahmaputra-Meghna River Basin

International Nuclear Information System (INIS)

Roy, Debasri; Goswami, A.B.; Bose, Balaram

2004-01-01

Sharing of water of transboundary rivers among riparian nations has become a cause of major concern in different parts of the globe for quite sometime. The issue in the recent decades has been transformed into a source of international tensions and disputes resulting in strained relationships between riparian nations. Conflicts over sharing of water of the international rivers, like the Tigris, Euphrates and Jordan in the Middle East, the Nile in Northern Africa, the Mekong in South-East Asia, the Ganga-Brahmaputra-Meghna in the Indian subcontinent are widely known. The present paper discusses the water sharing -issue in the Ganga- Brahmaputra-Meghna basin located in the Indian sub continent covering five sovereign countries (namely India, Nepal, China, Bhutan and Bangladesh). Rapidly growing population, expanding agricultural and industrial activities besides the impacts of climate change have resulted in stressed condition in the arena of fresh water availability in the basin. Again occurrence of arsenic in sub-surface water in the lower reaches of the basin in India and Bangladesh has also added a new dimension to the problem. All the rivers of the GBM system exhibit wide variations between peak and lean flows as major part of the basin belongs to the monsoon region, where 80%-90 % of annual rainfall is concentrated in 4-5 months of South -West monsoon in the subcontinent. Over and above, the rivers in GBM system carry huge loads of sediments along with the floodwater and receive huge quantum of different kinds of wastes contaminating the water of the rivers. Again high rate of sedimentation of the major rivers and their tributaries have been affecting not only the carrying capacity of the rivers but also drastically reduced their retention capacity. Almost every year during monsoon about 27% and nearly 60% of the GBM basin lying in India and Bangladesh respectively experience flood. The year round navigation in many rivers has also been affected. All these have

Ground-water quality in the Red River of the North Basin, Minnesota and North Dakota, 1991-95

Science.gov (United States)

Cowdery, T.K.

1998-01-01

Surveys of water quality in surficial, buried glacial, and Cretaceous aquifers in the Red River of the North Basin during 1991-95 showed that some major-ion, nutrient, pesticide, and radioactive-element concentrations differed by physiographic area and differed among these aquifer types. Waters in surficial aquifers in the Drift Prairie (west) and Lake Plain (central) physiographic areas were similar to each other but significantly higher than those in the Moraine (east) area in dissolved solids, sodium, potassium, sulfate, fluoride, silica, and uranium concentrations. Radium, iron, nitrate, and nitrite concentrations were also significantly different among these areas. Pesticides were detected in 12 percent of waters in surficial aquifers in the Drift Prairie area, 20 percent of those in the Lake Plain area, and 52 percent of those in the Moraine area. Triazines and bentazon accounted for 98 percent of summed pesticide concentrations in waters in surficial aquifers. Waters in buried glacial aquifers in the central one-third of the basin had significantly higher concentrations of dissolved solids, sodium, potassium, chloride, fluoride, and iron than did waters in surficial aquifers. No pesticides were detected in five samples from buried glacial aquifers or six samples from Cretaceous aquifers. Waters in all sampled aquifers had a calcium-magnesium ratio of about 1.75 ± 0.75 across the basin regardless of anionic composition.

Umatilla River Basin Anadromous Fish Habitat Enhancement Project : 1995 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Shaw, R.Todd

1996-05-01

During the 1995 - 96 project period, four new habitat enhancement projects were implemented under the Umatilla River Basin Anadromous Fish Habitat Enhancement Project by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) in the upper Umatilla River Basin. A total of 38,644 feet of high tensile smooth wire fencing was constructed along 3.6 miles of riparian corridor in the Meacham Creek, Wildhorse Creek, Greasewood Creek, West Fork of Greasewood Creek and Mission Creek watersheds. Additional enhancements on Wildhorse Creek and the lower Greasewood Creek System included: (1) installation of 0.43 miles of smooth wire between river mile (RM) 10.25 and RM 10.5 Wildhorse Creek (fence posts and structures had been previously placed on this property during the 1994 - 95 project period), (2) construction of 46 sediment retention structures in stream channels and maintenance to 18 existing sediment retention structures between RM 9.5 and RM 10.25 Wildhorse Creek, and (3) revegetation of stream corridor areas and adjacent terraces with 500 pounds of native grass seed or close species equivalents and 5,000 native riparian shrub/tree species to assist in floodplain recovery, stream channel stability and filtering of sediments during high flow periods. U.S. Fish and Wildlife Service (USFWS), Bureau of Indian Affairs (BIA) and Environmental Protection Agency (EPA) funds were cost shared with Bonneville Power Administration (BPA) funds, provided under this project, to accomplish habitat enhancements. Water quality monitoring continued and was expanded for temperature and turbidity throughout the upper Umatilla River Watershed. Physical habitat surveys were conducted on the lower 13 river miles of Wildhorse Creek and within the Greasewood Creek Project Area to characterize habitat quality and to quantify various habitat types by area.

Hydrothermal and hydrochemical operating conditions of the cooling water basin of the Lithuanian thermalelectric station. Gidrotermicheskii i gidrokhimicheskii rezhim vodokhranilishcha - okhladitela Litovskoi GRES

Energy Technology Data Exchange (ETDEWEB)

Lasinskas, M

1981-01-01

Complex studies of the cooling water storage basin and its drainage system are described. Physical and geographical conditions (terrain, soil, vegetation, etc) of the drainage system and their influence on processes within the water basin are discussed. Inflow and discharge parts of the water balance, particularly the evaporation of hot water from the basin surface, are discussed. Data of long-term measurements of thermal conditions, heat exchange processes and their relation to the effectivity of the thermalelectric plant are presented. Heat balance of the water basin was determined. The influence of the Lithuanian Hydro upon precipitation, physical and chemical operating conditions of the water storage basin, and drainage and ground water was studied. The characteristics of the chemical composition of bottom sediments, intensity of current sedimentation processes and sediment accumulation in the water storage basin are given.

Radioactive liquid wastes discharged to ground in the 200 areas during the first three quarters of 1974

International Nuclear Information System (INIS)

Anderson, J.D.

1974-01-01

An overall summary of radioactive liquid wastes discharged to ground during the first three quarters of 1974 and since startup within the Production and Waste Management control zone is presented in tabular form. Estimates of the radioactivity discharged to individual ponds, cribs, and specific retention sites are given. (LK)

Implications of ground water chemistry and flow patterns for earthquake studies.

Science.gov (United States)

Guangcai, Wang; Zuochen, Zhang; Min, Wang; Cravotta, Charles A; Chenglong, Liu

2005-01-01

Ground water can facilitate earthquake development and respond physically and chemically to tectonism. Thus, an understanding of ground water circulation in seismically active regions is important for earthquake prediction. To investigate the roles of ground water in the development and prediction of earthquakes, geological and hydrogeological monitoring was conducted in a seismogenic area in the Yanhuai Basin, China. This study used isotopic and hydrogeochemical methods to characterize ground water samples from six hot springs and two cold springs. The hydrochemical data and associated geological and geophysical data were used to identify possible relations between ground water circulation and seismically active structural features. The data for delta18O, deltaD, tritium, and 14C indicate ground water from hot springs is of meteoric origin with subsurface residence times of 50 to 30,320 years. The reservoir temperature and circulation depths of the hot ground water are 57 degrees C to 160 degrees C and 1600 to 5000 m, respectively, as estimated by quartz and chalcedony geothermometers and the geothermal gradient. Various possible origins of noble gases dissolved in the ground water also were evaluated, indicating mantle and deep crust sources consistent with tectonically active segments. A hard intercalated stratum, where small to moderate earthquakes frequently originate, is present between a deep (10 to 20 km), high-electrical conductivity layer and the zone of active ground water circulation. The ground water anomalies are closely related to the structural peculiarity of each monitoring point. These results could have implications for ground water and seismic studies in other seismogenic areas.

An Archeological Overview and Management Plan for the Dugway Proving Ground.

Science.gov (United States)

1984-03-29

niches, particulary the lacustrine environment of the Great Basin (Baumhoff and Heizer 1965, Butler 1978, Heizer and Krieger 1956, Heizer and Harper...power that would capture the animals souls, rendering them docile and stupid (Steward 1970:34). Other large game was present, but were not numerous...uni versity. Baum, Bernard. 1947. Dugway Proving Ground. Aberdeen: U.S. Army Chemical Corps.* Bailmhoff, W.A. and R.F. Heizer . 1965. Postglacial

Monitoring species richness and abundance of shorebirds in the western Great Basin

Science.gov (United States)

Warnock, Nils; Haig, Susan M.; Oring, Lewis W.

1998-01-01

Broad-scale avian surveys have been attempted within North America with mixed results. Arid regions, such as the Great Basin, are often poorly sampled because of the vastness of the region, inaccessibility of sites, and few ornithologists. In addition, extreme variability in wetland habitat conditions present special problems for conducting censuses of species inhabiting these areas. We examined these issues in assessing multi-scale shorebird (order: Charadriiformes) censuses conducted in the western Great Basin from 1992-1997. On ground surveys, we recorded 31 species of shorebirds, but were unable to accurately estimate population size. Conversely, on aerial surveys we were able to estimate regional abundance of some shorebirds, but were unable to determine species diversity. Aerial surveys of three large alkali lakes in Oregon (Goose, Summer, and Abert Lakes) revealed > 300,000 shorebirds in one year of this study, of which 67% were American Avocets (Recurvirostra americana) and 30% phalaropes (Phalaropus spp.). These lakes clearly meet Western Hemisphere Shorebird Reserve Network guidelines for designation as important shorebird sites. Based upon simulations of our monitoring effort and the magnitude and variation of numbers of American Avocets, detection of S-10% negative declines in populations of these birds would take a minimum of 7-23 years of comparable effort. We conclude that a combination of ground and aerial surveys must be conducted at multiple sites and years and over a large region to obtain an accurate picture of the diversity, abundance, and trends of shorebirds in the western Great Basin.

Simulations of Precipitation Variability over the Upper Rio Grande Basin

International Nuclear Information System (INIS)

Costigan, Keeley R.; Bossert, James E.; Langley, David L.

1997-10-01

In this research, we study Albuquerque's water and how it may be affected by changes in the regional climate, as manifested by variations in Rio Grande water levels. To do this, we rely on the use of coupled atmospheric, runoff, and ground water models. Preliminary work on the project has focused on uncoupled simulations of the aquifer beneath Albuquerque and winter precipitation simulations of the upper Rio Grande Basin. The latter is discussed in this paper

Calibration parameters used to simulate streamflow from application of the Hydrologic Simulation Program-FORTRAN Model (HSPF) to mountainous basins containing coal mines in West Virginia

Science.gov (United States)

Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

2005-01-01

This report presents the Hydrologic Simulation Program-FORTRAN Model (HSPF) parameters for eight basins in the coal-mining region of West Virginia. The magnitude and characteristics of model parameters from this study will assist users of HSPF in simulating streamflow at other basins in the coal-mining region of West Virginia. The parameter for nominal capacity of the upper-zone storage, UZSN, increased from south to north. The increase in UZSN with the increase in basin latitude could be due to decreasing slopes, decreasing rockiness of the soils, and increasing soil depths from south to north. A special action was given to the parameter for fraction of ground-water inflow that flows to inactive ground water, DEEPFR. The basis for this special action was related to the seasonal movement of the water table and transpiration from trees. The models were most sensitive to DEEPFR and the parameter for interception storage capacity, CEPSC. The models were also fairly sensitive to the parameter for an index representing the infiltration capacity of the soil, INFILT; the parameter for indicating the behavior of the ground-water recession flow, KVARY; the parameter for the basic ground-water recession rate, AGWRC; the parameter for nominal capacity of the upper zone storage, UZSN; the parameter for the interflow inflow, INTFW; the parameter for the interflow recession constant, IRC; and the parameter for lower zone evapotranspiration, LZETP.

Reproduction of Baltic cod, Gadus morhua (Actinopterygii: Gadiformes: Gadidae), in the Gotland Basin: Causes of annual variability

DEFF Research Database (Denmark)

Plikshs, Maris; Hinrichsen, Hans-Harald; Elferts, D.

2015-01-01

observations during 1969–1995 on four stations in each of two transects. The oceanographic monitoring and demersal trawl research survey data from 1974–2012 have been used in analyses. Results. The sufficient reproduction conditions in the southern Gotland Basin persisted only until 1981. In later decades...... reproduction volume concept can be used as an ecological indicator for egg survival probability in the Gotland Basin. However, it is too premature to re-define the concept of the suitable reproduction volume because it is applicable only to the Gotland spawning ground...

Investigating groundwater salinity in the Machile-Zambezi Basin (Zambia) with hydrogeophysical methods

DEFF Research Database (Denmark)

Chongo, Mkhuzo; A. Nyambe, Imasiku; Larsen, Flemming

resources worldwide. This thesis presents the application of geo-electrical and electromagnetic methods for the investigation of groundwater salinity in the Machile-Zambezi Basin in south western Zambia, southern central Africa. Aerial and ground based transient electromagnetic measurenments were used...... use of direct current and transient electromagnetic data in one optimization. The result from the regional mapping with transient electromagnetic measurenments showed a spatial distribution of electrical resistivity that indicated block faulting in the Machile-Zambezi Basin. Saline groundwater...... parameters. This was for a coupled flow and solute transport model setup for the Kasaya transect under the forcing of evapotranspiration. Performance of the coupled hydrogeophysical inversion was better with the inclusion of direct current data in comparison to the use of transient electromagnetic data alone...

Geochemistry and arsenic behaviour in groundwater resources of the Pannonian Basin (Hungary and Romania)

International Nuclear Information System (INIS)

Rowland, Helen A.L.; Omoregie, Enoma O.; Millot, Romain; Jimenez, Cristina; Mertens, Jasmin; Baciu, Calin; Hug, Stephan J.; Berg, Michael

2011-01-01

Graphical abstract: Elevated As levels in the Pannonian Basin are mainly present in very old (Palaeo) groundwater of methanogenic Pliocene/Quaternary aquifers, which is in contrast to Asian regions where arsenic-enriched groundwater is generally much younger. Display Omitted Research highlights: → Arsenic originates from Late Pliocene/Quaternary aquifers and some very old waters. → Arsenic levels are controlled by both mobilisation and retention mechanisms. → Mobilisation is caused by biogeochemical reductive dissolution. → Sufficient sulfate supply triggers arsenic retention in sulfide precipitates. → Nearly 500,000 people are exposed to elevated arsenic in their drinking water. - Abstract: Groundwater resources in the Pannonian Basin (Hungary, Romania, Croatia and Serbia) are known to contain elevated naturally occurring As. Published estimates suggest nearly 500,000 people are exposed to levels greater than the EU maximum admissible concentration of 10 μg/L in their drinking water, making it the largest area so affected in Europe. In this study, a variety of groundwaters were collected from Romania and Hungary to elucidate the general geochemistry and identify processes controlling As behaviour. Concentrations ranged from 4 2- reduction containing low As levels ( 7 Li (an indicator of geothermal inputs) and As(tot) in geothermal/saline influenced waters indicate that elevated As is not from an external input, but is released due to an in-aquifer process. Geochemical reasoning, therefore, implies As mobilisation is controlled by redox processes, most likely microbially mediated reductive dissolution of As bearing Fe-oxides, known to occur in sediments from the area. More important is an overlying retention mechanism determined by the presence or absence of SO 4 2- . Ongoing SO 4 2- reduction will release S 2- , removing As from solution either by the formation of As-sulfides, or from sorption onto Fe-sulfide phases. In methanogenic waters, As released

Confirmation of Elevated Methane Emissions in Utah's Uintah Basin With Ground-Based Observations and a High-Resolution Transport Model

Science.gov (United States)

Foster, C. S.; Crosman, E. T.; Holland, L.; Mallia, D. V.; Fasoli, B.; Bares, R.; Horel, J.; Lin, J. C.

2017-12-01

Large CH4 leak rates have been observed in the Uintah Basin of eastern Utah, an area with over 10,000 active and producing natural gas and oil wells. In this paper, we model CH4 concentrations at four sites in the Uintah Basin and compare the simulated results to in situ observations at these sites during two spring time periods in 2015 and 2016. These sites include a baseline location (Fruitland), two sites near oil wells (Roosevelt and Castlepeak), and a site near natural gas wells (Horsepool). To interpret these measurements and relate observed CH4 variations to emissions, we carried out atmospheric simulations using the Stochastic Time-Inverted Lagrangian Transport model driven by meteorological fields simulated by the Weather Research and Forecasting and High Resolution Rapid Refresh models. These simulations were combined with two different emission inventories: (1) aircraft-derived basin-wide emissions allocated spatially using oil and gas well locations, from the National Oceanic and Atmospheric Administration (NOAA), and (2) a bottom-up inventory for the entire U.S., from the Environmental Protection Agency (EPA). At both Horsepool and Castlepeak, the diurnal cycle of modeled CH4 concentrations was captured using NOAA emission estimates but was underestimated using the EPA inventory. These findings corroborate emission estimates from the NOAA inventory, based on daytime mass balance estimates, and provide additional support for a suggested leak rate from the Uintah Basin that is higher than most other regions with natural gas and oil development.

Using satellite-based rainfall estimates for streamflow modelling: Bagmati Basin

Science.gov (United States)

Shrestha, M.S.; Artan, Guleid A.; Bajracharya, S.R.; Sharma, R. R.

2008-01-01

In this study, we have described a hydrologic modelling system that uses satellite-based rainfall estimates and weather forecast data for the Bagmati River Basin of Nepal. The hydrologic model described is the US Geological Survey (USGS) Geospatial Stream Flow Model (GeoSFM). The GeoSFM is a spatially semidistributed, physically based hydrologic model. We have used the GeoSFM to estimate the streamflow of the Bagmati Basin at Pandhera Dovan hydrometric station. To determine the hydrologic connectivity, we have used the USGS Hydro1k DEM dataset. The model was forced by daily estimates of rainfall and evapotranspiration derived from weather model data. The rainfall estimates used for the modelling are those produced by the National Oceanic and Atmospheric Administration Climate Prediction Centre and observed at ground rain gauge stations. The model parameters were estimated from globally available soil and land cover datasets – the Digital Soil Map of the World by FAO and the USGS Global Land Cover dataset. The model predicted the daily streamflow at Pandhera Dovan gauging station. The comparison of the simulated and observed flows at Pandhera Dovan showed that the GeoSFM model performed well in simulating the flows of the Bagmati Basin.

Contribution of the gravimetry to the structural study of the Haouz basin (Morocco)

International Nuclear Information System (INIS)

El Goumi, N.; Jaffal, M.; Kchikach, A.; Manar, A.

2010-01-01

The aim of the present study is to improve the knowledge of the Haouz basin structure using gravity data analysis. First of all, a residual anomaly map was computed from the Bouguer anomaly, greatly affected by an important regional gravity gradient. The calculated map provides information on the ground density variations mainly attributed to the top of the Paleozoic basement undulations under the sedimentary cover. However, in order to further study this map, it has been later analyzed with a method that allows evidencing different buried geological structures, combining the horizontal gradient and the upward continuations processing. The obtained results allows us to establish a structural map of the Haouz basin which confirms the existence of structures already recognized or assumed by the classic geological studies, and highlights accidents, as yet, unknown until the present time. This map shows that the fault system of the Haouz basin is organized in two families of directions NE-SW and NW-SE. (Author).

Slip pulse and resonance of Kathmandu basin during the 2015 Mw 7.8 Gorkha earthquake, Nepal imaged with space geodesy

Science.gov (United States)

Galetzka, John; Melgar, D.; Genrich, J.F.; Geng, J.; Owen, S.; Lindsey, E. O.; Xu, X.; Bock, Y.; Avouac, J.-P.; Adhikari, L. B.; Upreti, B. N.; Pratt-Sitaula, B.; Bhattarai, T. N.; Sitaula, B. P.; Moore, A.; Hudnut, Kenneth W.; Szeliga, W.; Normandeau, J.; Fend, M.; Flouzat, M; Bollinger, L.; Shrestha, P.; Koirala, B.; Gautam, U.; Bhatterai, M.; Gupta, R.; Kandel, T.; Timsina, C.; Sapkota, S.N.; Rajaure, S.; Maharjan, N.

2015-01-01

Detailed geodetic imaging of earthquake rupture enhances our understanding of earthquake physics and induced ground shaking. The April 25, 2015 Mw 7.8 Gorkha, Nepal earthquake is the first example of a large continental megathrust rupture beneath a high-rate (5 Hz) GPS network. We use GPS and InSAR data to model the earthquake rupture as a slip pulse of ~20 km width, ~6 s duration, and with peak sliding velocity of 1.1 m/s that propagated toward Kathmandu basin at ~3.3 km/s over ~140 km. The smooth slip onset, indicating a large ~5 m slip-weakening distance, caused moderate ground shaking at high >1Hz frequencies (~16% g) and limited damage to regular dwellings. Whole basin resonance at 4-5 s period caused collapse of tall structures, including cultural artifacts.

Carrying away and redistribution of radioisotopes on the Peyne catchment basin. Preliminary report

International Nuclear Information System (INIS)

Duffa, C.; Danic, F.

2006-01-01

The transfers of radioisotopes present in soils and sediments are essentially conditioned by the mobilities of the physical vectors which constitute their supports. The water is the main vector of natural transfer, radioisotopes being associated with it under dissolved or particulate shape. The rainout and the hydrous erosion are responsible in particular for the carrying away and for the redistribution of contaminants following an atmospheric deposit on a catchment basin. However their effect is not the same in any point of the catchment basin. The work begun here aims at elaborating a classification of the grounds sensitivity towards this phenomenon of radioisotopes carrying away. The different factors of sensitivity have been identified: pluviometry, slope, soils occupation and soils nature. The Peyne catchment basin, that presents an important variability of these four parameters, constitutes the experimental site for this study. On this catchment basin, we search to identify the areas the most sensitive to the carrying away of radioisotopes, by combining a theoretical predictive approach based on the cartography and a descriptive approach basing on the sampling and the analysis of soils samples. (N.C.)

76 FR 24089 - Credit Risk Retention

Science.gov (United States)

2011-04-29

... 17 CFR Part 246 Department of Housing and Urban Development 24 CFR Part 267 Credit Risk Retention... 2501-AD53 Credit Risk Retention AGENCIES: Office of the Comptroller of the Currency, Treasury (OCC..., Commission, FHFA, and HUD (the Agencies) are proposing rules to implement the credit risk retention...

Generation of Earthquake Ground Motion Considering Local Site Effects and Soil-Structure Interaction Analysis of Ancient Structures

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Kwan; Lee, J. S.; Yang, T. S.; Cho, J. R.; R, H. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-09-01

In order to establish a correct correlation between them, mechanical characteristics of the ancient structures need to be investigated. Since sedimentary basins are preferred dwelling sites in ancient times, it is necessary to perform SSI analysis to derive correct correlation between the damage and ground motion intensity. Contents of Project are as follows: (1) Generation of stochastic earthquake ground motion considering source mechanism and site effects. (2) Analysis of seismic response of sedimentary basin. (3) Soil-structure interaction analysis of ancient structures (4) Investigation of dynamic response characteristics of ancient structure considering soil-structure interaction effects. A procedure is presented for generation of stochastic earthquake ground motion considering source mechanism and site effects. The simulation method proposed by Boore is used to generate the outcropping rock motion. The free field motion at the soil site is obtained by a convolution analysis. And for the study of wood structures, a nonlinear SDOF model is developed. The effects of soil-structure interaction on the behavior of the wood structures are found to be very minor. But the response can be significantly affected due to the intensity and frequency contents of the input motion. 13 refs., 6 tabs., 31 figs. (author)

Ground-water availability in the eastern part of the Lake Ontario Basin, New York

Science.gov (United States)

Miller, Todd S.

1986-01-01

A set of three maps show surficial geology, significant unconsolidated aquifers and well yield, and selected well locations for the Lake Ontario basin, New York. In the low areas , glaciers and wave action of former high-level lakes deposited permeable sand and gravel to form aquifers that yield more than 10 gal/min of water to wells. Small quantities of water (less than 2 gal/min) can be pumped from dug wells that top till and fine lake-sediment deposits. (USGS)

Retention capacity of correlated surfaces.

Science.gov (United States)

Schrenk, K J; Araújo, N A M; Ziff, R M; Herrmann, H J

2014-06-01

We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.

Retention capacity of correlated surfaces

OpenAIRE

Schrenk, K. J.; Araújo, N. A. M.; Ziff, R. M.; Herrmann, H. J.

2014-01-01

We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.

[Variation characteristics and influencing factors of actual evapotranspiration under various vegetation types: A case study in the Huaihe River Basin, China.

Science.gov (United States)

Wu, Rong Jun; Xing, Xiao Yong

2016-06-01

The actual evapotranspiration was modelled utilizing the boreal ecosystem productivity simulator (BEPS) in Huaihe River Basin from 2001 to 2012. In the meantime, the quantitative analyses of the spatial-temporal variations of actual evapotranspiration characteristics and its influencing factors under different vegetation types were conducted. The results showed that annual evapotranspiration gradually decreased from southeast to northwest, tended to increase annually, and the monthly change for the average annual evapotranspiration was double-peak curve. The differences of evapotranspiration among vegetation types showed that the farmland was the largest contributor for the evapotranspiration of Huaihe Basin. The annual actual evapotranspiration of the mixed forest per unit area was the largest, and that of the bare ground per unit area was the smallest. The changed average annual evapotranspiration per unit area for various vegetation types indicated an increased tendency other than the bare ground, with a most significant increase trend for the evergreen broadleaf forest. The thermodynamic factors (such as average temperature) were the dominant factors affecting the actual evapotranspiration in the Huaihe Basin, followed by radiation and moisture factors.

Ground-water quality and geochemistry, Carson Desert, western Nevada

Science.gov (United States)

Lico, Michael S.; Seiler, R.L.

1994-01-01

Aquifers in the Carson Desert are the primary source of drinking water, which is highly variable in chemical composition. In the shallow basin-fill aquifers, water chemistyr varies from a dilute calcium bicarbonate-dominated water beneath the irrigated areas to a saline sodium chloride- dominated water beneath unirrigated areas. Water samples from the shallow aquifers commonly have dissolved solids, chloride, magnesium, sulfate, arsenic, and manganese concentrations that exceed State of Nevada drinking-water standards. Water in the intermediante basin-fill aquifers is a dilute sodium bicarbonate type in the Fallon area and a distinctly more saline sodium chloride type in the Soda Lake-Upsal Hogback area. Dissolved solids, chloride, arsenic, fluoride, and manganese concen- trations commonly exceed drinking-water standards. The basalt aquifer contains a dilute sodium bicarbonate chloride water. Arsenic concentrations exceed standards in all sampled wells. The concen- trations of major constituents in ground water beneath the southern Carson Desert are the result of evapotranspiration and natural geochemical reactions with minerals derived mostly from igneous rocks. Water with higher concentrations of iron and manganese is near thermodynamic equilibrium with siderite and rhodochrosite and indicates that these elements may be limited by the solubility of their respective carbonate minerals. Naturally occurring radionuclides (uranium and radon-222) are present in ground water from the Carson Desert in concen- tratons higher than proposed drinking-water standards. High uranium concentrations in the shallow aquifers may be caused by evaporative concentration and the release of uranium during dissolution of iron and manganese oxides or the oxidation of sedimentary organic matter that typically has elevated uranium concentrations. Ground water in the Carson Desert does not appear to have be contaminated by synthetic organic chemicals.

Decreasing Agricultural Irrigation has not reversed Groundwater Depletion in the Yellow River Basin

Science.gov (United States)

Kang, Z.; Xie, X.; Zhu, B.

2017-12-01

Agricultural irrigation is considered as the major water use sector accounting for over 60% of the global freshwater withdrawals. Especially in the arid and semiarid areas, irrigation from groundwater storage substantially sustain crop growth and food security. China's Yellow River Basin (YRB) is a typical arid and semiarid area with average annual precipitation about 450 mm. In this basin, more than 52 million hm2 of arable land needs irrigation for planting wheat, cotton, paddy rice etc, and groundwater contributes over one-third irrigation water. However, agricultural irrigation remained a certain level or decreased to some degree due to water-saving technologies and returning farmland to forest projects. Then an interesting question arises: has the groundwater storage (GWS) in YRB kept a consistent variation with the agricultural irrigation? In this study, to address this question, we employed multi-source data from ground measurements, remote sensing monitoring and large-scale hydrological modeling. Specifically, groundwater storage variation was identified using Gravity Recovery and Climate Experiment (GRACE) data and ground observations, and groundwater recharge was estimated based on the Variable Infiltration Capacity (VIC) modeling. Results indicated that GWS in YRB still holds a significant depletion with a rate of about -3 mm per year during the past decade, which was consistently demonstrated by the GRACE and the ground observations. Ground water recharge shows negligible upward trends despite climate change. The roles of different sectors contributing to groundwater depletion have changed. Agricultural irrigation accounting for over 60% of groundwater depletion, but its impact decreased. However, the domestic and the industrial purposes play an increasing role in shaping groundwater depletion.

Geophysical Measurements in the Beaver Basin, West-Central Utah; Part 1--Slingram, Magnetic, and Self-Potential Profiles

OpenAIRE

Flanigan, Vincent J.; Campbell, David L.; U.S. Geological Survey

1981-01-01

This report consists of figures showing profile locations (fig. 1, table 1) in the Beaver Basin, west-central Utah, and ground geophysical data collected in September 1980 along these traverses (figs. 2-11). These data consist of slingram electromagnetic (real and imaginary components at 222, 444, 888, 1777, and 3555 Hz), ground magnetic and self-potential measurements collected at 200-foot (61-m) intervals along about 8.8 miles (14.2 km) of survey line. Table 2 lists equipment used. The r...

Optimal Career Progression of Ground Combat Arms Officers in the Marine Reserve

OpenAIRE

Reamy, Stephen

2012-01-01

The purpose of this thesis is to examine career progression for ground combat arms officers in the Marine Corps Reserve, and to identify gaps between current and optimal career progression. Recent policy changes provide the catalyst for this thesis. On 4 December 2006, the Marine Corps announced the implementation of the Officer Candidate Course-Reserve. At the time, active component manpower practices and historically high retention rates resulted in reduced numbers of officers leaving activ...

Entrainment, retention, and transport of freely swimming fish in junction gaps between commercial barges operating on the Illinois Waterway

Science.gov (United States)

Davis, Jeremiah J.; Jackson, P. Ryan; Engel, Frank; LeRoy, Jessica Z.; Neeley, Rebecca N.; Finney, Samuel T.; Murphy, Elizabeth A.

2016-01-01

Large Electric Dispersal Barriers were constructed in the Chicago Sanitary and Ship Canal (CSSC) to prevent the transfer of invasive fish species between the Mississippi River Basin and the Great Lakes Basin while simultaneously allowing the passage of commercial barge traffic. We investigated the potential for entrainment, retention, and transport of freely swimming fish within large gaps (> 50 m3) created at junction points between barges. Modified mark and capture trials were employed to assess fish entrainment, retention, and transport by barge tows. A multi-beam sonar system enabled estimation of fish abundance within barge junction gaps. Barges were also instrumented with acoustic Doppler velocity meters to map the velocity distribution in the water surrounding the barge and in the gap formed at the junction of two barges. Results indicate that the water inside the gap can move upstream with a barge tow at speeds near the barge tow travel speed. Water within 1 m to the side of the barge junction gaps was observed to move upstream with the barge tow. Observed transverse and vertical water velocities suggest pathways by which fish may potentially be entrained into barge junction gaps. Results of mark and capture trials provide direct evidence that small fish can become entrained by barges, retained within junction gaps, and transported over distances of at least 15.5 km. Fish entrained within the barge junction gap were retained in that space as the barge tow transited through locks and the Electric Dispersal Barriers, which would be expected to impede fish movement upstream.

Ground-water reconnaissance of American Samoa

Science.gov (United States)

Davis, Daniel Arthur

1963-01-01

The principal islands of American Samoa are Tutuila, Aunuu, Ofu, Olosega, and Ta'u, which have a total area of about 72 square miles and a population of about 20,000. The mean annual rainfall is 150 to 200 inches. The islands are volcanic in origin and are composed of lava flows, dikes, tuff. and breccia, and minor amounts of talus, alluvium, and calcareous sand and gravel. Tutuila is a complex island formed of rocks erupted from five volcanoes. Aunuu is a tuff cone. Ofu, Olosega, and Ta'u are composed largely of thin-bedded lava flows. Much of the rock of Tutuila has low permeability, and most of the ground water is in high-level reservoirs that discharge at numerous small springs and seeps. The flow from a few springs and seeps is collected in short tunnels or in basins for village supply, but most villages obtain their water from streams. A large supply of basal ground water may underlie the Tafuna-Leone plain at about sea level in permeable lava flows. Small basal supplies may be in alluvial fill at the mouths of large valleys. Aunuu has small quantities of basal water in beach deposits of calcareous sand and gravel. Minor amounts of high-level ground-water flow from springs and seeps on Ofu, Olosega, and Ta'u. The generally permeable lava flows in the three islands contain substantial amounts of basal ground water that can be developed in coastal areas in wells dug to about sea level.

Uncovering client retention antecedents in service organizations

Directory of Open Access Journals (Sweden)

Mari Jansen van Rensburg

2014-01-01

Full Text Available This paper develops a multi-dimensional model of retention to provide a more complete and integrated view of client retention and its determinants in service contexts. To uncover the antecedents of client retention, social and economic exchanges were reviewed under the fundamental ideas of the Social Exchange Theory. Findings from a survey of senior South African advertising executives suggest that client retention is the result of evaluative as well as relational factors that can influence client responses. Despite contractual obligations, advertisers are willing to pay the costs and make the sacrifices of switching should their expectations be unmet. An important contribution of this study is the use of multi-item scales to measure retention. The model developed provides valuable insight to agencies on client retention management and the optimal allocation of resources for maximum customer equity. This model may also be applied to other service organisations to provide insight to client retention.

Detection of Ground Water Availability at Buhias Island, Sitaro Regency

Directory of Open Access Journals (Sweden)

Zetly E Tamod

2016-08-01

Full Text Available The study aims to detect ground water availability at Buhias Island, Siau Timur Selatan District, Sitaro Regency. The research method used the survey method by geoelectrical instrument based on subsurface rock resistivity as a geophysical exploration results with geoelectrical method of Wenner-Schlumberger configuration. Resistivity geoelectrical method is done by injecting a flow into the earth surface, then it is measured the potential difference. This study consists of 4 tracks in which each track is made the stretch model of soil layer on subsurface of ground.  Then, the exploration results were processed using software RES2DINV to look at the data of soil layer based on the value of resistivity (2D. Interpretation result of the track 1 to 4 concluded that there is a layer of ground water. State of dominant ground water contains the saline (brackish. Location of trajectory in the basin to the lowland areas is mostly mangrove swamp vegetation. That location is the junction between the results of the runoff of rainfall water that falls down from the hills with sea water. Bedrock as a constituent of rock layer formed from marine sediments that carry minerals salts.

Geology and ground water in the Platte-Republican Rivers watershed and the Little Blue River basin above Angus, Nebraska, with a section on chemical quality of the ground water

Science.gov (United States)

Johnson, C.R.; Brennan, Robert

1960-01-01

saturation because the ground water, as it percolates southeastward beneath the area, moves out of the Tertiary and into the Quaternary deposits without apparent hindrance. The water that enters the area as underflow from the west is augmented within the area by water that infiltrates from the land surface. The principal sources of irrigating water are precipitation, seepage from canals and reservoirs, and applied irrigation water. Except for the water withdrawn through wells or discharged by natural processes where valleys have been cut into the zone of saturation, ground water leaves the area as underflow into the Platte River valley on the north, the Blue River drainage basin on the east, or the Republican River valley on the south. Part of the water used for irrigation and watering livestock and all the water used in rural and urban homes, in public buildings, and for industrial purposes is obtained from wells, To date (1952) there is no indication that the supply of ground water is being depleted faster than it is being replenished; instead, studies indicate that greater quantities can be withdrawn without causing an excessive decline of the water table. An increase of ground-water withdrawals to a sustainable maximum, however, will be possible only if the points of withdrawal are scattered fairly uniformly. It is estimated that annual withdrawals per township should not exceed 2,100 acre-feet where infiltrating precipitation is the only source of recharge, or 3,000 acre-feet where other sources of recharge are significant. Although perennial withdrawals of this amount could be sustained indefinitely, they would cause some lowering of the water table and eventually a decrease in the amount of water discharged from the area by natural means. The ground water is of the calcium bicarbonate type. In much of the area it is hard or very hard, and in places it contains excessive amounts of iron. In all other respects the water is chemically suitable for domesti

GC51D-0831: A Study of the Impact of Dams on Sediment Retention in the Mekong River Basin

Science.gov (United States)

Munroe, Thailynn; Griffin, Robert; Anderson, Eric; Markert, Kel

2017-01-01

Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), developed at Texas A & M, a rainfall-runoff hydrologic model to determine change in sedimentation in the Mekong Basin after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu & Varis (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

Recruitment and retention strategies for expert nurses in abortion care provision.

Science.gov (United States)

McLemore, Monica R; Levi, Amy; James, E Angel

2015-06-01

The purpose of this thematic analysis is to describe recruitment, retention and career development strategies for expert nurses in abortion care provision. Thematic analysis influenced by grounded theory methods were used to analyze interviews, which examined cognitive, emotional, and behavioral processes associated with how nurses make decisions about participation in abortion care provision. The purposive sample consisted of 16 nurses, who were interviewed between November 2012 and August 2013, who work (or have worked) with women seeking abortions in abortion clinics, emergency departments, labor and delivery units and post anesthesia care units. Several themes emerged from the broad categories that contribute to successful nurse recruitment, retention, and career development in abortion care provision. All areas were significantly influenced by engagement in leadership activities and professional society membership. The most notable theme specific to recruitment was exposure to abortion through education as a student, or through an employer. Retention is most influenced by flexibility in practice, including: advocating for patients, translating one's skill set, believing that nursing is shared work, and juggling multiple roles. Lastly, providing on the job training opportunities for knowledge and skill advancement best enables career development. Clear mechanisms exist to develop expert nurses in abortion care provision. The findings from our study should encourage employers to provide exposure opportunities, develop activities to recruit and retain nurses, and to support career development in abortion care provision. Additionally, future workforce development efforts should include and engage nursing education institutions and employers to design structured support for this trajectory. Copyright © 2015 Elsevier Inc. All rights reserved.

The Central European Permian Basins; Rheological and structural controls on basin history and on inter-basin connectivity

NARCIS (Netherlands)

Smit, Jeroen; van Wees, Jan-Diederik; Cloetingh, Sierd

2014-01-01

We analyse the relative importance of the major crustal-scale fault zones and crustal architecture in controlling basin formation, deformation and the structural connections between basins. The North and South Permian Basins of Central Europe are usually defined by the extend of Rotliegend

Retention of Emergency Care Knowledge.

Science.gov (United States)

Burckes, Mardie E.; Shao, Kung Ping Pam

1984-01-01

Data on the emergency care knowledge of college students were measured by a pretest, posttest, and retention test. A high relationship was found between students' posttest scores and retention test scores. Findings are discussed. (Author/DF)

Magnetotelluric data collected near geophysically logged boreholes in the Espa?ola and Middle Rio Grande basins, New Mexico

Science.gov (United States)

Williams, Jackie M.; Rodriguez, Brian D.

2006-01-01

The Santa Fe region is growing rapidly. The Santa Fe Group aquifer in the Espa?ola Basin is the main source of municipal water for the region, and water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Tertiary Santa Fe Group. The Santa Fe Group includes the sedimentary deposits that fill the Rio Grande rift and contain the principal ground-water aquifers. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the Espa?ola Basin in northern New Mexico. Detailed geologic mapping, high-resolution airborne magnetic surveys, electromagnetic surveys, and hydrologic, lithologic, and hydro-geochemical data are being used to better understand the aquifer systems. Magnetotelluric (MT) surveys were completed as part of these studies. The primary purpose of the MT surveys was to map changes in electrical resistivity with depth that are related to differences in various rock types that help control the properties of aquifers in the region. Resistivity modeling of the MT data can be used to investigate buried structures related to the basic geologic framework of the study area. The purpose of this report is to release MT sounding data collected near geophysically logged boreholes in the study area, including the nearby Middle Rio Grande Basin. This MT data can be used in subsequent resistivity modeling. No interpretation of the data is included in this report.

Plastic debris retention and exportation by a mangrove forest patch

International Nuclear Information System (INIS)

Ivar do Sul, Juliana A.; Costa, Monica F.; Silva-Cavalcanti, Jacqueline S.; Araújo, Maria Christina B.

2014-01-01

Highlights: • Estuaries and mangrove forests are rarely studied for marine plastic debris loads. • Types of plastic items and mangrove forest habitats determine the potential of debris retention. • Mangrove habitats are temporary sinks of plastic debris from river and marine origins. • Plastics rapidly accumulate in mangrove forest, but are exported slowly. • Fauna and fishers using mangrove forest habitats are at risk of interaction with plastic debris. -- Abstract: An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years)

Comparative Research on River Basin Management in the Sagami River Basin (Japan and the Muda River Basin (Malaysia

Directory of Open Access Journals (Sweden)

Lay Mei Sim

2018-05-01

Full Text Available In the world, river basins often interwoven into two or more states or prefectures and because of that, disputes over water are common. Nevertheless, not all shared river basins are associated with water conflicts. Rivers in Japan and Malaysia play a significant role in regional economic development. They also play a significant role as water sources for industrial, domestic, agricultural, aquaculture, hydroelectric power generation, and the environment. The research aim is to determine the similarities and differences between the Sagami and Muda River Basins in order to have a better understanding of the governance needed for effectively implementing the lessons drawn from the Sagami River Basin for improving the management of the Muda River Basin in Malaysia. This research adopts qualitative and quantitative approaches. Semi-structured interviews were held with the key stakeholders from both basins and show that Japan has endeavored to present policy efforts to accommodate the innovative approaches in the management of their water resources, including the establishment of a river basin council. In Malaysia, there is little or no stakeholder involvement in the Muda River Basin, and the water resource management is not holistic and is not integrated as it should be. Besides that, there is little or no Integrated Resources Water Management, a pre-requisite for sustainable water resources. The results from this comparative study concluded that full support and participation from public stakeholders (meaning the non-government and non-private sector stakeholders is vital for achieving sustainable water use in the Muda River Basin. Integrated Water Resources Management (IWRM approaches such as the introduction of payments for ecosystems services and the development of river basin organization in the Muda River Basin should take place in the spirit of political willingness.

Modeling of Wave Propagation in the Osaka Sedimentary Basin during the 2013 Awaji Island Earthquake (Mw5.8)

Science.gov (United States)

Asano, K.; Sekiguchi, H.; Iwata, T.; Yoshimi, M.; Hayashida, T.; Saomoto, H.; Horikawa, H.

2013-12-01

The three-dimensional velocity structure model for the Osaka sedimentary basin, southwest Japan is developed and improved based on many kinds of geophysical explorations for decades (e.g., Kagawa et al., 1993; Horikawa et al., 2003; Iwata et al., 2008). Recently, our project (Sekiguchi et al., 2013) developed a new three-dimensional velocity model for strong motion prediction of the Uemachi fault earthquake in the Osaka basin considering both geophysical and geological information by adding newly obtained exploration data such as reflection surveys, microtremor surveys, and receiver function analysis (hereafter we call UMC2013 model) . On April 13, 2013, an inland earthquake of Mw5.8 occurred in Awaji Island, which is close to the southwestern boundary of the aftershock area of the 1995 Kobe earthquake. The strong ground motions are densely observed at more than 100 stations in the basin. The ground motion lasted longer than four minutes in the Osaka urban area where its bedrock depth is about 1-2 km. This long-duration ground motions are mainly due to the surface waves excited in this sedimentary basin whereas the magnitude of this earthquake is moderate and the rupture duration is expected to be less than 5 s. In this study, we modeled long-period (more than 2s) ground motions during this earthquake to check the performance of the present UMC2013 model and to obtain a better constraint on the attenuation factor of sedimentary part of the basin. The seismic wave propagation in the region including the source and the Osaka basin is modeled by the finite difference method using the staggered grid solving the elasto-dynamic equations. The domain of 90km×85km×25.5km is modeled and discretized with a grid spacing of 50 m. Since the minimum S-wave velocity of the UMC2013 model is about 250 m/s, this calculation is valid up to the period of about 1 s. The effect of attenuation is included in the form of Q(f)=Q0(T0/T) proposed by Graves (1996). A PML is implemented in

Short time-scale wind forced variability in the Río de la Plata Estuary and its role on ichthyoplankton retention

Science.gov (United States)

Simionato, C. G.; Berasategui, A.; Meccia, V. L.; Acha, M.; Mianzan, H.

2008-01-01

The Río de la Plata Estuary presents a strong bottom salinity front located over a submerged shoal. Apparently favored by retention processes, it is a spawning ground for several coastal fishes. This estuary is very shallow and essentially wind driven and, moreover, in time scales relevant to biota, estuarine circulation is wind dominated and highly variable. Two intriguing questions are, therefore, how this system can favor retention and what the involved mechanisms are. This paper qualitatively explores mechanisms involved in the estuary where retention is favored applying numerical simulations in which neutral particles - simulating fish eggs and early larvae - are released along the bottom frontal zone and tracked for different wind conditions. Results suggest that retentive features can be a consequence of estuarine response to natural wind variability acting over bathymetric features. For winds from most directions, particles either remain trapped near their launching position or move northeastward to southwestward along the shoal. As alternation of winds that favor along-shoal motion is the dominant feature of wind variability in the region, a retentive scenario results from prevailing wind variability. Additionally, winds that tend to export particles with a poor chance of being restored to the front are neither frequent nor persistent. Results show, therefore, that physical forcing alone might generate a retentive scenario at the inner part of this estuary. The physical retention mechanism is more effective for bottom than for surface launched particles. Wind statistics indicate that the proposed mechanism has different implications for retention along the seasons. Spring is the most favorable season, followed by summer, when particles would have a larger propensity to reach the southern area of the estuary (Samborombón Bay). Fall and winter are increasingly less favorable. All these features are consistent with patterns observed in the region in

Stratigraphic architecture of Devonian lacustrine basins of northern Scotland

DEFF Research Database (Denmark)

Kristiansen, Thorben; Moreau, Julien; Andrews, Steven D.

of this important surface has received relatively little attention. We have utilized vintage onshore seismic to gain a better understanding of the pre-Devonian basement physiography. Onshore exposures of the top Moine, base Devonian unconformity surface is exposed have been visited to ground truth our subsurface...... interpretations. The studied deposits have been deeply buried then exhumed so that they are exposed widely onshore. Post Caledonian tectonism has faulted and folded the Devonian succession making it challenging to reconstruct the stratigraphy and the basin architecture from geological data only. The Devonian...

Monitoring Changes in Croplands Due to Water Stress in the Krishna River Basin Using Temporal Satellite Imagery

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Venkata Ramana Murthy Reddi

2017-10-01

Full Text Available Remote sensing-based assessments of large river basins such as the Krishna, which supplies water to many states in India, are useful for operationally monitoring agriculture, especially basins that are affected by abiotic stress. Moderate-Resolution Imaging Spectroradiometer (MODIS time series products can be used to understand cropland changes at the basin level due to abiotic stresses, especially water scarcity. Spectral matching techniques were used to identify land use/land cover (LULC areas for two crop years: 2013–2014, which was a normal year, and 2015–2016, which was a water stress year. Water stress-affected crop areas were categorized into three classes—severe, moderate and mild—based on the normalized difference vegetation index (NDVI and intensity of damage assessed through field sampling. Furthermore, ground survey data were used to assess the accuracy of MODIS-derived classification individual products. Water inflows into and outflows from the Krishna river basin during the study period were used as direct indicators of water scarcity/availability in the Krishna Basin. Furthermore, ground survey data were used to assess the accuracy of MODIS-derived LULC classification of individual year products. Rainfall data from the tropical rainfall monitoring mission (TRMM was used to support the water stress analysis. The nine LULC classes derived using the MODIS temporal imagery provided overall accuracies of 82% for the cropping year 2013–2014 and 85% for the year 2015–2016. Kappa values are 0.78 for 2013–2014 and 0.82 for 2015–2016. MODIS-derived cropland areas were compared with national statistics for the cropping year 2013–2014 with a R2 value of 0.87. Results show that both rainfed and irrigated areas in 2015–2016 saw significant changes that will have significant impacts on food security. It has been also observed that the farmers in the basin tend to use lower inputs and labour per ha during drought years. Among

Streambed infiltration and ground-water flow from the trout creek drainage, an intermittent tributary to the Humboldt River, north-central Nevada: Chapter K in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

Science.gov (United States)

Prudic, David E.; Niswonger, Richard G.; Harrill, James R.; Wood, James L.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground water is abundant in many alluvial basins of the Basin and Range Physiographic Province of the western United States. Water enters these basins by infiltration along intermittent and ephemeral channels, which originate in the mountainous regions before crossing alluvial fans and piedmont alluvial plains. Water also enters the basins as subsurface ground-water flow directly from the mountains, where infiltrated precipitation recharges water-bearing rocks and sediments at these higher elevations. Trout Creek, a typical intermittent stream in the Middle Humboldt River Basin in north-central Nevada, was chosen to develop methods of estimating and characterizing streambed infiltration and ground-water recharge in mountainous terrains. Trout Creek has a drainage area of about 4.8 × 107 square meters. Stream gradients range from more than 1 × 10–1 meter per meter in the mountains to 5 × 10–3 meter per meter at the foot of the piedmont alluvial plain. Trout Creek is perennial in short reaches upstream of a northeast-southwest trending normal fault, where perennial springs discharge to the channel. Downstream from the fault, the water table drops below the base of the channel and the stream becomes intermittent.Snowmelt generates streamflow during March and April, when streamflow extends onto the piedmont alluvial plain for several weeks in most years. Rates of streambed infiltration become highest in the lowest reaches, at the foot of the piedmont alluvial plain. The marked increases in infiltration are attributed to increases in streambed permeability together with decreases in channel-bed armoring, the latter which increases the effective area of the channel. Large quartzite cobbles cover the streambed in the upper reaches of the stream and are absent in the lowest reach. Such changes in channel deposits are common where alluvial fans join piedmont alluvial plains. Poorly sorted coarse and fine sediments are deposited near the head of the fan, while

A Self-Calibrating Runoff and Streamflow Remote Sensing Model for Ungauged Basins Using Open-Access Earth Observation Data

Directory of Open Access Journals (Sweden)

Ate Poortinga

2017-01-01

Full Text Available Due to increasing pressures on water resources, there is a need to monitor regional water resource availability in a spatially and temporally explicit manner. However, for many parts of the world, there is insufficient data to quantify stream flow or ground water infiltration rates. We present the results of a pixel-based water balance formulation to partition rainfall into evapotranspiration, surface water runoff and potential ground water infiltration. The method leverages remote sensing derived estimates of precipitation, evapotranspiration, soil moisture, Leaf Area Index, and a single F coefficient to distinguish between runoff and storage changes. The study produced significant correlations between the remote sensing method and field based measurements of river flow in two Vietnamese river basins. For the Ca basin, we found R2 values ranging from 0.88–0.97 and Nash–Sutcliffe efficiency (NSE values varying between 0.44–0.88. The R2 for the Red River varied between 0.87–0.93 and NSE values between 0.61 and 0.79. Based on these findings, we conclude that the method allows for a fast and cost-effective way to map water resource availability in basins with no gauges or monitoring infrastructure, without the need for application of sophisticated hydrological models or resource-intensive data.

Drainage basins features and hydrological behaviour river Minateda basin

International Nuclear Information System (INIS)

Alonso-Sarria, F.

1991-01-01

Nine basin variables (shape, size and topology) have been analyzed in four small basins with non-permanent run off (SE of Spain). These geomorphological variables have been selected for their high correlation with the Instantaneous unit hydrograph parameters. It is shown that the variables can change from one small basin to another within a very short area; because of it, generalizations about the behaviour of the run off are not possible. In conclusion, it is stated that the variations in geomorphological aspects between different basins, caused mainly by geological constraints, are a very important factor to be controlled in a study of geoecological change derived from climatic change

A simplified GIS-based model for large wood recruitment and connectivity in mountain basins

Science.gov (United States)

Lucía, Ana; Antonello, Andrea; Campana, Daniela; Cavalli, Marco; Crema, Stefano; Franceschi, Silvia; Marchese, Enrico; Niedrist, Martin; Schneiderbauer, Stefan; Comiti, Francesco

2014-05-01

The mobilization of large wood (LW) elements in mountain rivers channels during floods may increase their hazard potential, especially by clogging narrow sections such as bridges. However, the prediction of LW transport magnitude during flood events is a challenging topic. Although some models on LW transport have been recently developed, the objective of this work was to generate a simplified GIS-based model to identify along the channel network the most likely LW-related critical sections during high-magnitude flood events in forested mountain basins. Potential LW contribution generated by landsliding occurring on hillslopes is assessed using SHALSTAB stability model coupled to a GIS-based connectivity index, developed as a modification of the index proposed by Cavalli et al (2013). Connected slope-derived LW volumes are then summed at each raster cell to LW volumes generated by bank erosion along the erodibile part of river corridors, where bank erosion processes are estimated based on user-defined channel widening ratios stemming from observations following recent extreme events in mountain basins. LW volume in the channel is then routed through the stream network applying simple Boolean rules meant to capture the most important limiting transport condition in these high-energy systems at flood stage, i.e. flow width relative to log length. In addition, the role of bridges and retention check-dams in blocking floating logs is accounted for in the model, in particular bridge length and height are used to characterize their clogging susceptibility for different levels of expected LW volumes and size. The model has been tested in the Rienz and Ahr basins (about 630 km2 each), located in the Eastern Italian Alps. Sixty percent of the basin area is forested, and elevations range from 811 m a.s.l. to 3488 m a.s.l.. We used a 2.5 m resolution DTM and DSM, and their difference was used to calculate the canopy height. Data from 35 plots of the National Forest Inventory

On the optimal design of risk retention in securitisation

Directory of Open Access Journals (Sweden)

Metin Kaptan

2011-09-01

Full Text Available This paper examines the optimal design of retention in securitisation, in order to maximize welfare of screening per unit of retention, assuming that screening is costly and that the bank intends to securitise its loans. In contrast to the focus of previous literature on tranche retention, we deviate from the constitutional mechanisms of tranche retention to present a pareto-optimal method of tranche retention. Unlike the current ad-hoc-regulations, we derive the optimal design of retention from a utility maximization problem. We show that the level of retention per tranche should be dependent on the rate of credit default, i.e. the higher the rate of default, the higher the optimal rate of retention required to provide an incentive to screen carefully. From this approach, it follows that the rate of retention per tranche should be higher, the higher the position within the ranking order of subordination. Accordingly, the efficiency of tranche retention can be enhanced, reducing the level of retention required to maintain a given level of screening-effort. This retention design entails a recovery of the bank’s equity capital, thereby increasing liquidity and lending capacities.

Some feature of evaporarion from the ground suface of tibetan plateau

OpenAIRE

ZHANG, Yinsheng; YABUKI, Hironori; YAO, Tandong; PU, Jianchen; OHATA, Tetsuo

1997-01-01

[ABSTRACT] The processes of evaporation on the ground in Dongkemadi River Basin near the Tanggula Pass were observed with weighting-lysimeter method from May to September 1993, and some preliminary results were got. Evaporation mainly occurred from May to September and the daily mean soil evaporation in July is higher than in other months; there is a nice linear relationship between the soil evaporation and water evaporation which observed in 20 cm evaporation pan; the soil evaporation is muc...

The Effects of Long-Duration Spaceflight on Training Retention and Transfer

Science.gov (United States)

Barshi, Immanuel; Healy, Alice; Dempsey, Donna L.; McGuire, Kerry M.; Landon, Lauren B.

2018-01-01

Training our crew members for long duration, exploration-class missions will have to maximize long-term retention and transfer of the trained skills. The expected duration of the missions, our inability to predict all the possible tasks the crew will be called upon to perform, and the low training-to-mission time ratio require that the training be maximally effective such that the skills acquired during training will be retained and will be transferrable across a wide range of specific tasks that are different from the particular tasks used during training. However, to be able to design training that can achieve these ambitious goals, we must first understand the ways in which long-duration spaceflight affects training retention and transfer. Current theories of training retention and transfer are largely based on experimental studies conducted at university laboratories using undergraduate students as participants. Furthermore, all such studies have been conducted on Earth. We do not know how well the results of these studies predict the performance of crew members. More specifically, we do not know how well the results of these studies predict the performance of crew members in space and especially during long-duration missions. To address this gap in our knowledge, the current on-going study seeks to test the null hypothesis that performance of university undergraduate students on Earth on training retention and transfer tests do in fact predict accurately the performance of crew members during long-duration spaceflights. To test this hypothesis, the study employs a single 16-month long experimental protocol with 3 different participant groups: undergraduate university students, crew members on the ground, and crew members in space. Results from this study will be presented upon its completion. This poster presents results of study trials of the two tasks used in this study: a data entry task and a mapping task. By researching established training principles, by

RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

Energy Technology Data Exchange (ETDEWEB)

Robert Caldwell

1998-04-01

Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies

Optimum combination of water drainage, water supply and eco-environment protection in coal-accumulated basin of North China

Institute of Scientific and Technical Information of China (English)

武强; 董东林; 石占华; 武雄; 孙卫东; 叶责钧; 李树文; 刘金韬

2000-01-01

The conflict among water drainage, water supply and eco-environment protection is getting more and more serious due to the irrational drainage and exploitation of ground water resources in coal-accumulated basins of North China. Efficient solutions to the conflict are to maintain long-term dynamic balance between input and output of the ground water basins, and to try to improve resourcification of the mine water. All solutions must guarantee the eco-environment quality. This paper presents a new idea of optimum combination of water drainage, water supply and eco-environment protection so as to solve the problem of unstable mine water supply, which is caused by the changeable water drainage for the whole combination system. Both the management of hydraulic techniques and constraints in economy, society, ecology, environment, industrial structural adjustments and sustainable developments have been taken into account. Since the traditional and separate management of different departments of water drainage,

Retention of 137Cs and 90Sr by mineral sorbents surrounding vitrified nuclear waste

International Nuclear Information System (INIS)

Lyon, K.E.; Patterson, R.J.

1985-01-01

In June 1960, twenty-five 14-cm diameter hemispheres of vitrified nuclear waste (glass blocks) were buried in a shallow sand aquifer in the lower Perch Lake Basin, Chalk River Nuclear Laboratories, Ontario, Canada. Almost all leaching of the glass blocks occurred during the first 18 months of emplacement, and consequently the burial experiment approximated a single-injection source of 137 Cs and 90 Sr. After about 11 years, most of the 90 Sr that was released had been advected and dispersed from the site, whereas the bulk of the 137 Cs had travelled no more than 0.3 m from the blocks. Three piezometers were installed and five cores of sediment were collected at the glass block site in 1978. Mineralogically pure segregates of sand grains were prepared by hand and characterized using binocular, petrographic and scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A technique also was developed to measure very low levels of 137 Cs and 90 Sr by counting small (10-100 mg) sediment samples directly with a thin window, flow proportional counter. Results show that sand-sized grains of altered biotite (biotite-vermiculite), biotite, muscovite, hornblende and serictized feldspar are able to retain 137 Cs over a period of 18 years, and that grains of biotite-vermiculite, biotite and hematite-bearing feldspar (largely microline) can retain low levels of 90 Sr over the same period of time. The amounts of 137 Cs and 90 Sr sorbed by the mineral grains ranged from undetectable levels to approximately 380 and 35 becquerels/gram sediment, respectively. This report contains the complete series of mineral segregates ranked on a weight basis according to the amounts of retained 137 Cs and 90 Sr. Ground-water quality data indicate that none of the retention is the result of the precipitation of strontium or cesium minerals

A STUDY ON THE PATHOGENESIS OF YOLK RETENTION IN BROILER CHICKS

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Kashif Aziz Khan. Shakeel Akhtar Khan, Shahnaz Hamid2. Asim Aslam and Masood

2002-04-01

Full Text Available The present project was designed to identify the factors responsible for yolk retention in broiler chicks. Four different experiments were conducted to find out the effect of four factors (experimental yolk sac infection with Echerichia coli, off-feed period between hatching and housing. first feeding time in the poultry house and type of initial feed on yolk absorption. Results of these experiments showed that yolk sac infection with E. coli led to decrease in rate of yolk absorption. Moisture and protein percentage was increased in infected yolk but fat percentage was not affected by yolk sac infection. On the other hand, post hatch starvation due to delay in housing and delay in first feeding did not affect rate of yolk absorption. Moisture percentage was not affected while fat absorption increased and protein absorption decreased due to fasting. It was also observed that feeding ground corn in early life of chick led to slow absorption of yolk contents as compared to feeding commercial starter ration and 2% sugar solution. Yolk composition was not affected by feeding commercial starter ration, ground corn and 2% sugar solution in early life of chick. It is concluded that experimental infection with E. coli and ground corn as initial feed leads to slow absorption of yolk sac in young broiler chicks.

Data Retention and Anonymity Services

Science.gov (United States)

Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

Using GRACE to constrain precipitation amount over cold mountainous basins

Science.gov (United States)

Behrangi, Ali; Gardner, Alex S.; Reager, John T.; Fisher, Joshua B.

2017-01-01

Despite the importance for hydrology and climate-change studies, current quantitative knowledge on the amount and distribution of precipitation in mountainous and high-elevation regions is limited due to instrumental and retrieval shortcomings. Here by focusing on two large endorheic basins in High Mountain Asia, we show that satellite gravimetry (Gravity Recovery and Climate Experiment (GRACE)) can be used to provide an independent estimate of monthly accumulated precipitation using mass balance equation. Results showed that the GRACE-based precipitation estimate has the highest agreement with most of the commonly used precipitation products in summer, but it deviates from them in cold months, when the other products are expected to have larger errors. It was found that most of the products capture about or less than 50% of the total precipitation estimated using GRACE in winter. Overall, Global Precipitation Climatology Project (GPCP) showed better agreement with GRACE estimate than other products. Yet on average GRACE showed 30% more annual precipitation than GPCP in the study basins. In basins of appropriate size with an absence of dense ground measurements, as is a typical case in cold mountainous regions, we find GRACE can be a viable alternative to constrain monthly and seasonal precipitation estimates from other remotely sensed precipitation products that show large bias.

Estimates of long-term water total phosphorus (TP) concentrations in three large shallow lakes in the Yangtze River basin, China.

Science.gov (United States)

Wu, Pan; Qin, Boqiang; Yu, Ge

2016-03-01

The shallow lakes in the eastern China developed on alluvial plains with high-nutrient sediments, and most overflow into the Yangtze River with short hydraulic residence times, whereas they become eutrophic over long time periods. Assuming strong responses to hydrogeological changes in the basin, we attempted to determine the dynamic eutrophication history of these lakes. Although evaluation models for internal total phosphorus (TP) loading are widely used for deep lakes in Europe and North America, the accuracy of these models for shallow lakes that have smaller water volumes controlled by the geometrical morphology and greater basin area of alluvial plains is unknown. To describe the magnitude of changes in velocity of trophic state for the studied shallow lakes, we first evaluated the P retention model in relation to the major forces driving lake morphology, basin climate, and external discharge and then used the model to estimate changes in TP in three large shallow lakes (Taihu, Chao, and Poyang) over 60 years (1950-2009 AD). The observed levels of TP were verified against the relative error of the three lakes (Yangtze River basin. This work will contribute to the development of an internal P loading model for further evaluating trophic states.

Consequences of artificial deepwater ventilation in the Bornholm Basin for oxygen conditions, cod reproduction and benthic biomass - a model study

Science.gov (United States)

Stigebrandt, A.; Rosenberg, R.; Råman Vinnå, L.; Ödalen, M.

2015-01-01

We develop and use a circulation model to estimate hydrographical and ecological changes in the isolated basin water of the Bornholm Basin. By pumping well-oxygenated so-called winter water to the greatest depth, where it is forced to mix with the resident water, the rate of deepwater density reduction increases as well as the frequency of intrusions of new oxygen-rich deepwater. We show that pumping 1000 m3 s-1 should increase the rates of water exchange and oxygen supply by 2.5 and 3 times, respectively. The CRV (cod reproduction volume), the volume of water in the isolated basin meeting the requirements for successful cod reproduction (S > 11, O2 > 2 mL L-1), should every year be greater than 54 km3, which is an immense improvement, since it has been much less in certain years. Anoxic bottoms should no longer occur in the basin, and hypoxic events will become rare. This should permit extensive colonization of fauna on the earlier periodically anoxic bottoms. Increased biomass of benthic fauna should also mean increased food supply to economically valuable demersal fish like cod and flatfish. In addition, re-oxygenation of the sediments should lead to increased phosphorus retention by the sediments.

Surface Water Interim Measures/Interim Remedial Action Plan/Environmental Assessment and Decision Document, South Walnut Creek Basin, Operable Unit No. 2

International Nuclear Information System (INIS)

1991-01-01

Volume 2 of this IM/IRA Plan contains OU 2 surface water, sediment, ground water and soil chemistry data, as well as the South Walnut Creek Basin Surface Water IM/IRA schedule and a tabulation of ARARs. (FL)

Impact of Renewed Solar Dimming on Hydrology of River Basins in Peninsular India

Science.gov (United States)

Srivastava, R.; Soni, P.; Tripathi, S.

2017-12-01

A significant decrease in surface solar radiation (SSR) for the period 1970-2000 has been reported by observational studies over India. This trend has also been observed globally and is termed as solar dimming. A recent study reported a reversal in the SSR trends over India for the period 2001-2010. However, using SSR observations at 12 stations located across India, we found that a much stronger dimming has reappeared during the last decade (2006-2015). To analyse the hydrological impact of this renewed dimming, 28 river basins in peninsular India are studied using a semi-distributed hydrological model, Soil and Water Assessment Tool (SWAT). The area of these basins ranges from 1,260 km2 to 40,000 km2. The model was calibrated for the period 2003-2009 and validated for the period 2010-2014 using the daily discharge data. Experiments were performed, based on observed SSR trends and their uncertainties, to quantify their impacts on the water balance of each basin. The results suggest that a 5-10% decrease in SSR over the 9-year period, 2006-2014, resulted in a decrease of about 8% in annual evapotranspiration (ET). Seasonally, ET decreased during wet seasons (monsoon and post-monsoon) leading to increased ground water recharge, but increased during dry seasons (winter and pre-monsoon) resulting in reduced soil moisture. Changes in ET were also affected by the basin characteristics. Forested basins with clay loam soils were found to have higher ET changes than other basins. Annual discharge from the basins increased due to the decrease in annual ET caused by the decrease in SSR. The results suggest that effects of SSR trends on annual runoff are significant over peninsular Indian and should not to be neglected as they can affect river flow projections and freshwater availability.

Best practices in doctoral retention: Mentoring

Directory of Open Access Journals (Sweden)

Judie L. Brill

2014-06-01

Full Text Available  The aim of this critical literature review is to outline best practices in doctoral retention and the successful approach of one university to improve graduation success by providing effective mentorship for faculty and students alike. The focus of this literature review is on distance learning relationships between faculty and doctoral students, regarding retention, persistence, and mentoring models. Key phrases and words used in the search and focusing on mentoring resulted in over 20,000 sources. The search was narrowed to include only doctoral study and mentoring. Research questions of interest were: Why do high attrition rates exist for doctoral students? What are the barriers to retention? What are the benefits of doctoral mentoring? What programs do institutions have in place to reduce attrition? The researchers found a key factor influencing doctoral student retention and success is effective faculty mentorship. In particular, the design of a mentoring and faculty training program to increase retention and provide for success after graduation is important. This research represents a key area of interest in the retention literature, as institutions continue to search for ways to better support students during their doctoral programs and post-graduation. DOI: 10.18870/hlrc.v4i2.186

Water infiltration in an aquifer recharge basin affected by temperature and air entrapment

Directory of Open Access Journals (Sweden)

Loizeau Sébastien

2017-09-01

Full Text Available Artificial basins are used to recharge groundwater and protect water pumping fields. In these basins, infiltration rates are monitored to detect any decrease in water infiltration in relation with clogging. However, miss-estimations of infiltration rate may result from neglecting the effects of water temperature change and air-entrapment. This study aims to investigate the effect of temperature and air entrapment on water infiltration at the basin scale by conducting successive infiltration cycles in an experimental basin of 11869 m2 in a pumping field at Crepieux-Charmy (Lyon, France. A first experiment, conducted in summer 2011, showed a strong increase in infiltration rate; which was linked to a potential increase in ground water temperature or a potential dissolution of air entrapped at the beginning of the infiltration. A second experiment was conducted in summer, to inject cold water instead of warm water, and also revealed an increase in infiltration rate. This increase was linked to air dissolution in the soil. A final experiment was conducted in spring with no temperature contrast and no entrapped air (soil initially water-saturated, revealing a constant infiltration rate. Modeling and analysis of experiments revealed that air entrapment and cold water temperature in the soil could substantially reduce infiltration rate over the first infiltration cycles, with respective effects of similar magnitude. Clearly, both water temperature change and air entrapment must be considered for an accurate assessment of the infiltration rate in basins.

Land Water Storage within the Congo Basin Inferred from GRACE Satellite Gravity Data

Science.gov (United States)

Crowley, John W.; Mitrovica, Jerry X.; Bailey, Richard C.; Tamisiea, Mark E.; Davis, James L.

2006-01-01

GRACE satellite gravity data is used to estimate terrestrial (surface plus ground) water storage within the Congo Basin in Africa for the period of April, 2002 - May, 2006. These estimates exhibit significant seasonal (30 +/- 6 mm of equivalent water thickness) and long-term trends, the latter yielding a total loss of approximately 280 km(exp 3) of water over the 50-month span of data. We also combine GRACE and precipitation data set (CMAP, TRMM) to explore the relative contributions of the source term to the seasonal hydrological balance within the Congo Basin. We find that the seasonal water storage tends to saturate for anomalies greater than 30-44 mm of equivalent water thickness. Furthermore, precipitation contributed roughly three times the peak water storage after anomalously rainy seasons, in early 2003 and 2005, implying an approximately 60-70% loss from runoff and evapotranspiration. Finally, a comparison of residual land water storage (monthly estimates minus best-fitting trends) in the Congo and Amazon Basins shows an anticorrelation, in agreement with the 'see-saw' variability inferred by others from runoff data.

Risk assessment of desertification using GIS in parts of Mond Basin, Southern Iran

International Nuclear Information System (INIS)

Masoudi, M.; Asrari, E.

2009-01-01

The present paper attempts to evolve a new model by considering various indicators of different types of land degradation desertification, namely water erosion, soil salinity, vegetation degradation, and lowering of ground water table. the Mond river basin, located centrally to this zone, has been selected as a test area to assess the risk and kind of desertification. For this purpose two sub basins of the Payab and Quareh Aghaj have been chosen for detailed study. The thresholds for the severity classes of indicators have been established and then the hazards map for each indicator of types of desertification has been prepared in a GIS. The risk maps of water erosion, soil salinization, lowering of water table, vegetation degradation have been produced for each of the two sub basins. It was possible to distinguish the areas under actual risk from areas under potential risk of desertification types. Also areas under potential risk are classified to subclasses with different probability level to show a statistical picture of risk in future. (Author) 3 refs.

Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

Science.gov (United States)

Quesada, C. A.; Phillips, O. L.; Schwarz, M.; Czimczik, C. I.; Baker, T. R.; Patiño, S.; Fyllas, N. M.; Hodnett, M. G.; Herrera, R.; Almeida, S.; Alvarez Dávila, E.; Arneth, A.; Arroyo, L.; Chao, K. J.; Dezzeo, N.; Erwin, T.; di Fiore, A.; Higuchi, N.; Honorio Coronado, E.; Jimenez, E. M.; Killeen, T.; Lezama, A. T.; Lloyd, G.; López-González, G.; Luizão, F. J.; Malhi, Y.; Monteagudo, A.; Neill, D. A.; Núñez Vargas, P.; Paiva, R.; Peacock, J.; Peñuela, M. C.; Peña Cruz, A.; Pitman, N.; Priante Filho, N.; Prieto, A.; Ramírez, H.; Rudas, A.; Salomão, R.; Santos, A. J. B.; Schmerler, J.; Silva, N.; Silveira, M.; Vásquez, R.; Vieira, I.; Terborgh, J.; Lloyd, J.

2012-06-01

Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the

The role of complex site and basin response in Wellington city, New Zealand, during the 2016 Mw 7.8 Kaikōura earthquake and other recent earthquake sequences.

Science.gov (United States)

Kaiser, A. E.; McVerry, G.; Wotherspoon, L.; Bradley, B.; Gerstenberger, M.; Benites, R. A.; Bruce, Z.; Bourguignon, S.; Giallini, S.; Hill, M.

2017-12-01

We present analysis of ground motion and complex amplification characteristics in Wellington during recent earthquake sequences and an overview of the 3D basin characterization and ongoing work to update site parameters for seismic design. Significant damage was observed in central Wellington, New Zealand's capital city, following the 2016 Mw7.8 Kaikōura earthquake. Damage was concentrated in mid-rise structures (5 - 15 storeys) and was clearly exacerbated by the particular characteristics of ground motion and the presence of basin effects. Due to the distance of the source (50 - 60km) from the central city, peak ground accelerations were moderate (up to 0.28g) and well within ultimate limit state (ULS) design levels. However, spectral accelerations within the 1 -2 s period range, exceeded 1 in 500 year design level spectra (ULS) in deeper parts of the basin. Amplification with respect to rock at these locations reached factors of up to 7, and was also observed with factors up to at least three across all central city soil recording sites. The ground motions in Wellington were the strongest recorded in the modern era of instrumentation. While similar amplification was observed during the 2013 Mw 6.6 Cook Strait and Grassmere earthquakes, which struck close to the termination of the Kaikōura earthquake rupture, these sources were not sufficiently large to excite significant long-period motions. However, other M7.2+ sources in the region that dominate the seismic hazard, e.g. Wellington Fault, Hikurangi subduction interface and other large proximal crustal faults, are also potentially capable of exciting significant long-period basin response in Wellington. These observations and the expectation of ongoing heightened seismicity have prompted re-evaluation of the current seismic demand levels. Additional field campaigns have also been undertaken to update geotechnical properties and the 3D basin model, in order to inform ongoing research and seismic design practice.

A Study on Employee Retention Techniques

OpenAIRE

Savarimuthu, Dr. A; Hemalatha, N.

2013-01-01

The objective of perusing this study is to assess the level of satisfaction of employee retention techniques at GB Engineering Enterprises PVT Limited., Trichy.This study gains significance because of employee retention techniques can be approached from various angles. It is desirable state of existence involving retention strategies generally fall in to one of four categories salary, working conditions, job enrichment and education. These four elements together constitute. The structure of e...

Estimation of Surface Runoff in the Jucar River Basin from Rainfall Data and SMOS Soil Moisture

Science.gov (United States)

Garcia Leal, Julio A.; Estrela, Teodoro; Fidalgo, Arancha; Gabaldo, Onofre; Gonzalez Robles, Maura; Herrera Daza, Eddy; Khodayar, Samiro; Lopez-Baeza, Ernesto

2013-04-01

Surface runoff is the water that flows after soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. When the soil is saturated and the depression storage filled, and rain continues to fall, the rainfall will immediately produce surface runoff. The Soil Conservation Service Curve Number (SCS-CN) method is widely used for determining the approximate direct runoff volume for a given rainfall event in a particular area. The advantage of the method is its simplicity and widespread inclusion in existing computer models. It was originally developed by the US Department of Agriculture, Soil Conservation Service, and documented in detail in the National Engineering Handbook, Sect. 4: Hydrology (NEH-4) (USDA-SCS, 1985). Although the SCS-CN method was originally developed in the United States and mainly for the evaluation of storm runoff in small agricultural watersheds, it soon evolved well beyond its original objective and was adopted for various land uses and became an integral part of more complex, long-term, simulation models. The basic assumption of the SCS-CN method is that, for a single storm, the ratio of actual soil retention after runoff begins to potential maximum retention is equal to the ratio of direct runoff to available rainfall. This relationship, after algebraic manipulation and inclusion of simplifying assumptions, results in the following equation given in USDA-SCS (1985): (P--0,2S)2 Q = (P + 0,8S) where Q is the average runoff (mm), P the effective precipitation (mm) and S is potential maximum retention (mm) after the rainfall event. The study has been applied to the Jucar River Basin area, East of Spain. A selection of recent significant rainfall events has been made corresponding to the periods around 22nd November, 2011 and 28-29 September and 10 October, 2012, from Jucar River Basin Authority rain gauge data. Potential maximum retention values for each point have been assumed as the first

Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

Science.gov (United States)

Gingerich, Stephen B.

1999-01-01

The study area lies on the northern flank of the East Maui Volcano (Haleakala) and covers about 129 square miles between the drainage basins of Maliko Gulch to the west and Makapipi Stream to the east. About 989 million gallons per day of rainfall and 176 million gallons per day of fog drip reaches the study area and about 529 million gallons per day enters the ground-water system as recharge. Average annual ground-water withdrawal from wells totals only about 3 million gallons per day; proposed (as of 1998) additional withdrawals total about 18 million gallons per day. Additionally, tunnels and ditches of an extensive irrigation network directly intercept at least 10 million gallons per day of ground water. The total amount of average annual streamflow in gaged stream subbasins upstream of 1,300 feet altitude is about 255 million gallons per day and the total amount of average annual base flow is about 62 million gallons per day. Six major surface-water diversion systems in the study area have diverted an average of 163 million gallons per day of streamflow (including nearly all base flow of diverted streams) for irrigation and domestic supply in central Maui during 1925-97. Fresh ground water is found in two main forms. West of Keanae Valley, ground-water flow appears to be dominated by a variably saturated system. A saturated zone in the uppermost rock unit, the Kula Volcanics, is separated from a freshwater lens near sea level by an unsaturated zone in the underlying Honomanu Basalt. East of Keanae Valley, the ground-water system appears to be fully saturated above sea level to altitudes greater than 2,000 feet. The total average annual streamflow of gaged streams west of Keanae Valley is about 140 million gallons per day at 1,200 feet to 1,300 feet altitude. It is not possible to estimate the total average annual streamflow at the coast. All of the base flow measured in the study area west of Keanae Valley represents ground-water discharge from the high

Methods and Data Used to Investigate Polonium-210 as a Source of Excess Gross-Alpha Radioactivity in Ground Water, Churchill County, Nevada

Science.gov (United States)

Seiler, Ralph L.

2007-01-01

Ground water is the major source of drinking water in the Carson River Basin, California and Nevada. Previous studies have shown that uranium and gross-alpha radioactivities in ground water can be greater than U.S. Environmental Protection Agency Maximum Contaminant Levels, particularly in the Carson Desert, Churchill County, Nevada. Studies also have shown that the primary source of the gross-alpha radioactivity and alpha-emitting radionuclides in ground water is the dissolution of uranium-rich granitic rocks and basin-fill sediments that have their origins in the Sierra Nevada. However, ground water sampled from some wells in the Carson Desert had gross-alpha radioactivities greater than could be accounted for by the decay of dissolved uranium. The occurrence of polonium-210 (Po-210) was hypothesized to explain the higher than expected gross-alpha radioactivities. This report documents and describes the study design, field and analytical methods, and data used to determine whether Po-210 is the source of excess gross-alpha radioactivity in ground water underlying the Carson Desert in and around Fallon, Nevada. Specifically, this report presents: 1) gross alpha and uranium radioactivities for 100 wells sampled from June to September 2001; and 2) pH, dissolved oxygen, specific conductance, and Po-210 radioactivity for 25 wells sampled in April and June 2007. Results of quality-control samples for the 2007 dataset are also presented.

Hydrology of the Upper Malad River basin, southeastern Idaho

Science.gov (United States)

Pluhowski, Edward J.

1970-01-01

greatest in July when about 7 inches is lost from lakes, reservoirs, and waterlogged areas; losses from free-water surfaces may be as much .as 38 inches annually. An extensive ground-water reservoir consisting of sand and gravel interbedded with relatively impermeable beds of silt .and clay underlies much of the Malad Valley. Wells near the center of the valley exceeding 700 feet in depth do not reach bedrock. The Woodruff fault, which transects the constricted lower Malad Valley, is one of the main factors creating artesian conditions south of the latitude of Malad City. Recharge is obtained principally from mountain runoff which flows onto highly permeable alluvial fans surrounding the valley and from streams that flow across the valley floor. On the basis of a water balance analysis, under flow from the project area was estimated to be 28,000 acre-feet annually, surface-water outflow was 51,000 acre-feet, and transbasin imports were about 4,000 acre-feet. The principal tributaries of the Malad River are perennial along their upper and middle reaches and have well-sustained low flows. During the growing season, all surface water entering the Malad Valley is used for irrigation. Spine irrigation is practiced in the principal tributary valleys; however, a shortage of suitable reservoir sites has hampered surface-water development in these areas. The highly porous deposits underlying the Malad Valley tend to attenuate flood peaks. An unusual combination of meteorologic events early in 1962 effectively counteracted the high absorptive capacity of the valley and predisposed the basin to high flood risk. Subsequent rapid snowmelt combined with frozen ground produced the extraordinary flood of February 12, 1962. Calcium and bicarbonate commonly are the most abundant ions in the surface waters of the upper Malad River basin. In August 1967, the dissolved-solids content of streamflow ranged from 200 to 350 milligrams per liter in the middle and upper parts of the basin; however

Annotated bibliography on artificial recharge of ground water, 1955-67

Science.gov (United States)

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

Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

Science.gov (United States)

Schöpfer, Kateřina; Hinsch, Ralph

2017-04-01

The Vøring and the Faroe-Shetland basins are offshore deep sedimentary basins which are situated on the outer continental margin of the northeast Atlantic Ocean. Both basins are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both basins share several common features: (i) Pre-Cretaceous faults that are distributed across the entire basin width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two basins: (i) The Faroe-Shetland Basin was a fault-controlled basin during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring Basin is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-basinal and marginal highs. In addition, the Cretaceous strata in the Vøring Basin are folded. (ii) In the Vøring Basin, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western basin margin, whereas in the Faroe-Shetland Basin Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases

Landslide inventory updating by means of Persistent Scatterer Interferometry (PSI: the Setta basin (Italy case study

Directory of Open Access Journals (Sweden)

Frangioni Sara

2015-07-01

Full Text Available This paper illustrates the contribution of Persistent Scatterer SAR Interferometry (PSInSAR technique to landslide detection, using interferometric data acquired in C-band by European remote-sensing satellite (ERS 1/2 and environmental satellite (ENVISAT satellites. The main purpose is to update a pre-existing landslide inventory map, by changing or confirming the landslide geometry and state of activity and eventually, identifying new phenomena.This work presents an application of satellite remote sensing to analyse ground displacement movements in the Setta basin, located on the northern Appennine (Bologna province, Italy and extended up 268 km2.The proposed methodology, resting upon pre-existing works already consolidated in the scientific community, combines interferometric measures with aerial imagery and other auxiliary data, in order to detect landslide indicators, finally validated with field surveys. The use of an activity matrix allows the identification of the state of activity of landslide phenomena with respect to the velocity of the radar displacement rates. Field validations are carried out in the areas that are more relevant because of the highest ground velocities and the presence of structures extensively affected by ground movements.The final updated landslide database of the Setta basin, based on Persistent Scatterer Interferometry analysis and in situ checks, consists of 1550 landslides, 236 of which have persistent scatterer information.

The Use of Isotope Techniques to Separate of Hydrography Components. Case Study: Ankara-Guvenc Basin

International Nuclear Information System (INIS)

Tekeli, Y.I.; Sorman, A.U.; Sayin, M.

2002-01-01

In this research, a stable environmental isotope study was carried out from analysis of water samples collected from rainfall, runoff (total discharge), springs (subsurface flows), and wells (ground waters)in Ankara-Guevenc basin having a drainage area of about 16.125 km 2 between 1996-2000. The aim of the study was to investigate the rainfall-runoff relationship for the basin. Recorded total ten discharge hydrographs are separated to their components using stable isotopes (Oxygen-18, Deuterium) contents. Among these samples, unit hydrographs from two one-peak storm hydrographs were derived using both isotope and graphical methods, and the derived unit hydrographs values including peaks were compared. Peak values of 10 and 20 minutes unit hydrographs of the basin derived by using isotope method (Q p = 1322 1/s and Q p = 1327 l/s) are compared with those of graphical method (Q p = 1656 1/s, and Q p = 1250 1/s) using Barnes semi-log approach. It was found out that, the contribution of subsurface flow which is component of total discharge hydrograph and originating from various sub layers are important in the total flow of basin using isotope method of approach

Winter Ground Temperatures Control Snowmelt DOC Export From a Discontinuous Permafrost Watershed: A Multi-Year Perspective

Science.gov (United States)

Carey, S. K.

2006-12-01

For discontinuous and continuous permafrost watersheds, the largest mass flux of dissolved organic carbon (DOC) occurs during the snowmelt period. During this time, available allochtonous organic carbon that has accumulated over the winter in frozen organic soils is rapidly flushed to the basin outlet. While this process has been observed now in many river systems of different size and location, there have been few inter-annual reports on the mass of DOC loss and the factors controlling its variability during freshet. Hydrological and DOC fluxes were recorded for the 2002, 2003 and 2006 snowmelt season with supplementary over-winter data for an 8 square kilometer sub-basin (Granger Basin) of the Wolf Creek Research Basin, Yukon Territory, Canada. Granger Basin is an alpine catchment above treeline underlain with discontinuous permafrost (approximately 70 %) and has widespread surface organic soils up to 0.4 m in thickness. Pre-melt snow water equivalent varied widely throughout the basin, yet was greatest in 2006, followed by 2002 and 2003. Ground temperatures were notably colder throughout the 2003 winter compared with 2006 and 2002. For all years, discharge began in mid-May, and was a continuous event in 2002 and 2006. In 2003 four distinct melt-periods were observed due to rising and falling temperatures. During freshet, stream DOC concentration increased rapidly from 15 mg C/L on the first ascending limb of the hydrograph in each year. In 2003, DOC was largely flushed from the catchment several weeks prior to peak freshet. DOC concentration in wells and piezometers followed a similar pattern to streamflow DOC, with 2003 groundwater DOC concentrations less than 2002 and 2006. The total mass flux of DOC during freshet was 0.85, 0.45 and 1.01 g C/m2 for 2002, 2003 and 2006 respectively. Despite differences in pre-melt snow accumulation, the timing of melt and the volume of discharge, it appears that spring DOC export is largely controlled by over-winter ground

Sources and chronology of nitrate contamination in spring waters, Suwannee River basin, Florida

Science.gov (United States)

Katz, Brian G.; Hornsby, H.D.; Bohlke, J.K.; Mokray, M.F.

1999-01-01

A multi-tracer approach, which consisted of analyzing water samples for n aturally occurring chemical and isotopic indicators, was used to better understand sources and chronology of nitrate contamination in spring wate rs discharging to the Suwannee and Santa Fe Rivers in northern Florida. Dur ing 1997 and 1998, as part of a cooperative study between the Suwannee River Water Management District and the U.S. Geological Survey, water samples were collected and analyzed from 24 springs and two wells for major ions, nutrients, dissolved organic carbon, and selected environmental isotopes [18O/16O, D/H, 13C/12C, 15N/14N]. To better understand when nitrate entered the ground-water system, water samples were analyzed for chlorofluorocarbons (CFCs; CCl3F, CCl2F2, and C2Cl3F3) and tritium (3H); in this way, the apparent ages and residence times of spring waters and water from shallow zones in the Upper Floridan aquifer were determined. In addition to information obtained from the use of isotopic and other chemical tracers, information on changes in land-use activities in the basin during 1954-97 were used to estimate nitrogen inputs from nonpoint sources for five counties in the basin. Changes in nitrate concentrations in spring waters with time were compared with estimated nitrogen inputs for Lafayette and Suwannee Counties. Agricultural activities [cropland farming, animal farming operations (beef and dairy cows, poultry, and swine)] along with atmospheric deposition have contributed large quantities of nitrogen to ground water in the Suwannee River Basin in northern Florida. Changes in agricultural land use during the past 40 years in Alachua, Columbia, Gilchrist, Lafayette, and Suwannee Counties have contributed variable amounts of nitrogen to the ground-water system. During 1955-97, total estimated nitrogen from all nonpoint sources (fertilizers, animal wastes, atmospheric deposition, and septic tanks) increased continuously in Gilchrist and Lafayette Counties. In

Fission-product retention in HTGR fuels

International Nuclear Information System (INIS)

Homan, F.J.; Kania, M.J.; Tiegs, T.N.

1982-01-01

Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed

Mobile Learning and Student Retention

Directory of Open Access Journals (Sweden)

Bharat Inder Fozdar

2007-06-01

Full Text Available Student retention in open and distance learning (ODL is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not been well researched. The main aim of our research, therefore, is to better understand and measure students’ attitudes and perceptions towards the effectiveness of mobile learning. Our hope is to determine how this technology can be optimally used to improve student retention at Bachelor of Science programmes at Indira Gandhi National Open University (IGNOU in India. For our research, we used a survey. Results of this survey clearly indicate that offering mobile learning could be one method improving retention of BSc students, by enhancing their teaching/ learning and improving the efficacy of IGNOU’s existing student support system. The biggest advantage of this technology is that it can be used anywhere, anytime. Moreover, as mobile phone usage in India explodes, it offers IGNOU easy access to a larger number of learners. This study is intended to help inform those who are seeking to adopt mobile learning systems with the aim of improving communication and enriching students’ learning experiences in their ODL institutions.

Aquifers in the Sokoto basin, northwestern Nigeria, with a description of the general hydrogeology of the region

Science.gov (United States)

Anderson, H.R.; Ogilbee, William

1973-01-01

The Sokoto Basin of northwestern Nigeria lies in the sub-Saharan Sudan belt of west Africa in a zone of savannah-type vegetation. Rainfall, averaging about 30 inches annually in much of the basin, occurs chiefly in a wet season which lasts from May to October. A prolonged dry season extending from October to April is dominated by dusty harmattan winds from the northeast. April and May are the hottest months, when temperatures occasionally reach 105?F. Flow in streams of the Sokoto Basin is mostly overland runoff. Only in a few reaches, fed by ground-water discharge from the sedimentary rocks, are streams perennial. In the River Zamfara basin, ground-water discharge contributes almost 1 inch of the average 3.33 inches of total annual runoff. In the vicinity of Sokoto, the River Rima flows throughout the year sustained by spring discharge from perched ground water in limestone of the Kalambaina Formation. On the crystalline terrane where most of the streams rise, total annual runoff may exceed 5 inches, very little of which is ground-water discharge. The sedimentary rocks of the basin range in age from Cretaceous to Tertiary and are composed mostly of interbedded sand, clay, and some limestone; the beds dip gently toward the northwest. Alluvium of Quaternary age underlies the lowlands of the River Sokoto (now Sokoto) and its principal tributaries. These rocks contain three important artesian aquifers, in addition to regional unconfined ground-water bodies in all the principal outcron areas, and a perched water body in the outcrop of the Kalambaina Formation. Artesian aquifers occur at depth in the Gundumi Formation, the Rima Group, and the Gwandu Formation and are separated from one another by clay beds in the lower part of the Rima Group and the Dange Formation. In outcrop, clay in the Dange Formation also supports the perched water of the Kalambaina Formation. The Gundumi Formation, resting on the basement complex, is composed of varicolored clay, sand, and gravel

THE STRUCTURE OF THE WATER CONSTRUCTIONS IN THE SEBES HYDROGRAPHIC BASIN AND THE STORAGE RESERVOIRS. EFFECT ON THE AVERAGE DISCHARGE

Directory of Open Access Journals (Sweden)

Stef Iulian Ioan

2013-05-01

Full Text Available In the upper basin of the Sebes Valley, the oldest storage lakes have been temporary artificial lakes, called haituri in Romanian. They were created within the forest exploitation areas. Inside the dams of those retention lakes, which dams are made of a wooden skeleton, filled with soil and stones, there have been weirs for the quick discharge of the water, having the purpose of creating some flood trends, capable of carrying over the logs, downstream the lake. At present, some of those temporary artificial lakes are used as trout farms, while others are damaged, or operate as basins for the sedimentation of the alluvial deposits. The difference of level between the springs of the Sebes and the Mures Rivers generates a convertible hydroelectric potential, having an average power exceeding 60,000 kW" />

Resolving superimposed ground-water contaminant plumes characterized by chromium, nitrate, uranium, and technetium--99

International Nuclear Information System (INIS)

Hall, S.H.

1990-02-01

Leakage from a liquid waste storage and solar evaporation basin at the Hanford Site in southeastern Washington State has resulted in a ground-water contaminant plume characterized by nitrate, hexavalent chromium, uranium, and technetium-99. The plume is superimposed on a larger, pre-existing plume extending from upgradient sites and having the same suite of contaminants. However, the relative abundance of contaminant species is quite different for each plume source. Thus, characteristic concentration ratios, rather than concentrations of individual species, are used as geochemical tracers, with emphasis on graphical analysis. Accordingly, it has been possible to resolve the boundaries of the smaller plume and to estimate the contribution of each plume to the observed contamination downgradient from the storage basin. 11 refs., 7 figs

HPLC retention thermodynamics of grape and wine tannins.