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Sample records for alluvial plains

  1. Level III Ecoregions of the Mississippi Alluvial Plain

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ecoregions for the Mississippi Alluvial Plain were extracted from the seamless national shapefile. Ecoregions denote areas of general similarity in ecosystems and in...

  2. Level IV Ecoregions of the Mississippi Alluvial Plain

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ecoregions for the Mississippi Alluvial Plain were extracted from the seamless national shapefile. Ecoregions denote areas of general similarity in ecosystems and in...

  3. Geomorphology of the Namoi alluvial plain, northwestern New South Wales

    International Nuclear Information System (INIS)

    Young, R.W.; Young, A.R.M.; Price, D.M.; Wray, R.A.L.

    2002-01-01

    The Quaternary history of the extensive alluvial plains of the northern part of the Darling River Basin has received little attention, and has generally been assumed to be an analogue of the very detailed history compiled for the Riverine Plain of southeastern Australia. Our study of the Namoi valley, which is a tributary to the upper Darling, shows that this assumption is unfounded. Thermoluminescence dating demonstrates that the oldest palaeochannels of the Namoi River correspond only to the youngest palaeochannels on the Riverine Plain. The thermoluminescence analyses were carried out on the 90-125 μm quartz fraction thermally stimulated by ionizing radiation using the combined additive/regenerative technique. This technique utilises a second glow normalisation procedure that involves re-irradiating each of the quartz sample aliquots and measuring the thermoluminescence induced in the grains. It has ben demonstrated that unlike the streams on the Riverine Plain, the Namoi River has moved progressively away from its buried Tertiary palaeovalley, probably due to declining sediment input from its southern tributaries. In contrast to the streams of the Riverine Plain, the dimensions of the Namoi palaeochannels are indicative of substantially greater discharges until the mid-Holocene. There is also evidence of significant aeolian input throughout the Late Quaternary. The study indicates that the water resources of this increasingly important irrigated region seem to be considerably constrained by the Quaternary heritage of the Namoi valley. Copyright (2002) Geological Society of Australia

  4. Towards groundwater neutral cropping systems in the Alluvial Fans of the North China Plain

    NARCIS (Netherlands)

    Oort, van P.A.J.; Wang, G.; Vos, J.; Meinke, H.; Li, B.G.; Huang, J.K.; Werf, van der W.

    2016-01-01

    Groundwater levels in the North China Plain (NCP), the bread basket of China, have dropped more than one meter per year over the last 40 years, putting at risk the long term productivity of this region. Groundwater decline is most severe in the Alluvial Fans where our study site is located.

  5. Hydrogeochemistry of Groundwater and Arsenic Adsorption Characteristics of Subsurface Sediments in an Alluvial Plain, SW Taiwan

    Directory of Open Access Journals (Sweden)

    Libing Liao

    2016-12-01

    Full Text Available Many studies were conducted to investigate arsenic mobilization in different alluvial plains worldwide. However, due to the unique endemic disease associated with arsenic (As contamination in Taiwan, a recent research was re-initiated to understand the transport behavior of arsenic in a localized alluvial plain. A comprehensive approach towards arsenic mobility, binding, and chemical speciation was applied to correlate groundwater hydrogeochemistry with parameters of the sediments that affected the As fate and transport. The groundwater belongs to a Na-Ca-HCO3 type with moderate reducing to oxidizing conditions (redox potential = −192 to 8 mV. Groundwater As concentration in the region ranged from 8.89 to 1131 μg/L with a mean of 343 ± 297 μg/L, while the As content in the core sediments varied from 0.80 to 22.8 mg/kg with a mean of 9.9 ± 6.2 mg/kg. A significant correlation was found between As and Fe, Mn, or organic matter, as well as other elements such as Ni, Cu, Zn, and Co in the core sediments. Sequential extraction analysis indicated that the organic matter and Fe/Mn oxyhydroxides were the major binding pools of As. Batch adsorption experiments showed that the sediments had slightly higher affinity for As(III than for As(V under near neutral pH conditions and the As adsorption capacity increased as the contents of Fe oxyhydroxides as well as the organic matter increased.

  6. Nutrient resorption efficiency of cocoa plantson lowl and of Alluvial plain

    Directory of Open Access Journals (Sweden)

    Rudy Erwiyono

    2011-05-01

    Full Text Available Observation on nutrient retranslocation of cocoa plants has been carried out in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute (ICCRI in Jember in order to assess its efficiency to have better understanding on the loss of nutrients through cocoa litterfall relatively intensive during dry season, better utilization of the plant litters, and further more efficient plant management. Nutrient retranslocation assessment has been conducted for macro nutrients in terms of N, P, and K that have been observed on four clones of cocoa planted in 2004, that are KW 163, KW 162, KKM 22, and KW 165 in the plot with Tectona grandis shading trees and plot with Cassia surithensis shading trees, with five replicates. The plots of observation overlaid on Alluvial plain 45 m asl. and D type rainfall. The results showed that nutrient contents in senescence leaves with yellow colour and then falling significantly lower than those of mature leaves with green colour adjacent to it. Reductions of N, P, and K contents during leaf senescence occured significantly on KW 163, KW 162, and KKM 22 clones, whereas on KW 165 clone significant reduction only happened to phosphorus. Mature leaves of cocoa with green colour contained average nitrogen, phosphorus, and kalium at 13.0, 1.6, and 13.5 mg/g- respectively. Whereas senescing leaves with yellow colour then defoliating contained average nitrogen, phosphorus, and kalium at 9.5, 0.9, and 10.0 mg/g, respectively. This reduction of nutrient contents was caused by nutrient retranslocation mechanism of the plants. Nitrogen, phosphorus, and kalium retranslocated by cocoa plants in rainy season are as much as 3.60, 0.70, and 3.39 mg/g, or 27%, 42%, and 24%, respectively. In other words nutrient retranslocation efficiency of cocoa plants for N, P, and K is in the following order: P>N>K. Among the clones, KKM 22 clone retranslocated P and K most efficiently; whereas for N, KW 162 clone retranslocated it

  7. Soil Moisture and Turgidity of Selected Robusta Coffee Clones on Alluvial Plain with Seasonal Rainfall Pattern

    Directory of Open Access Journals (Sweden)

    Rudy Erwiyono

    2005-08-01

    Full Text Available Observation on the seasonal variations of hydrological condition and turgidity of selected Robusta coffee clones has been carried out in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute in Jember. The aim was to evaluate the effect of hydrological variation on the coffee plants and the degree of soil moisture effect on plant performance. Experimental site overlays on alluvial plain, + 45 m a.s.l., 8o 15’ South with D rainfall type. Observation was conducted by survey method at the experimental plots of organic fertilizer and nitogen treatments on selected Robusta coffee clones derived from rooted cuttings, i.e. BP 436, BP 42, BP 936 and BP 358. Observation was only conducted at the experimental blocks of organic matter trials of 20 l/tree/year at nitrogen (Urea application of locally recommanded rate during the subsequent years of 1999 to 2001. Parameters observed included plant turgidity and soil moisture content of three different depths, i.e. 0—20, 20—40 and 40—60 cm and the weather. Observation was carried out in five replicates designed as blocks of barn manure treatment and N-fertilizer of recommended rate as basal fertilizer. The results showed that meteorological condition and soil moisture of experimental site through the years have seasonal patterns following the seasonal pattern of rainfall. Compared to other meteorological characteristics, relative humidity dominantly determined evaporation and plant turgidity. Plant turgi-dity was not only determined by soil moisture condition, but also atmospheric demand. When relative humidity (RH was relatively high, plant turgidity was relatively stable although soil moisture of surface layers was very low, and the reversal when soil moisture content was high plant turgidity was controlled by atmospheric demand (relative humidity. With a 3—4 dry month period, relative turgidity of the coffee plants was relatively stable above 82%, except when soil

  8. Highway 61 Revisited: Finding Drivers for Hypoxia in Aquatic Systems in the Mississippi Alluvial Plain

    Science.gov (United States)

    Shields, F., Jr.; Murdock, J. N.; Lizotte, R. E., Jr.; Knight, S. S.; Locke, M. A.; Testa, S., III

    2011-12-01

    Streams and lakes in the intensively cultivated Mississippi River alluvial plain frequently experience periods of hypoxia that are evidence of ecological stress. Although hydrologic perturbations and sediments and nutrients derived from nonpoint sources are likely drivers of these conditions, the most efficient pathway for obtaining partial ecological recovery (e.g., N load reduction or P load reduction or flow augmentation or erosion control) is not clear. To gain deeper understanding of these systems, three similar ~20 km2 watersheds in northwestern Mississippi were selected for study and instrumented for collection of hydrologic and water quality data in 2011. Aquatic systems within each watershed consisted of shallow natural lakes embedded in networks of sporadically flowing ditches, natural channels and wetlands, with hydrology strongly impacted by irrigation withdrawals from groundwater and return flows to surface water bodies. Waters were usually turbid, with mean Secchi disk readings 10-15 cm and mean suspended solids concentrations 200-600 mg/L. Strong diurnal fluctuations in dissolved oxygen concentration (DO) occurred even in the wetter, cooler winter months, with up to 50% of daily means below state standards (5 mg/L). The average diurnal range (daily max-daily min) in DO varied from 0.9 to 2.5 mg/L for lakes and from 1.7 to 6.0 mg/L for channels. Attendant extreme diurnal variations in temperature and pH were also observed. Observations of chlorophyll a concentrations, water column phytoplankton, and attached algae indicate the importance of algal photosynthesis and respiration to DO levels, but these processes are limited by light availability and N and P concentrations in a complex fashion. Light levels are governed by channel width, water depth and turbidity, which is due to suspended sediment and algae. Preliminary nutrient limitation studies showed both N and P limit algal growth, and microbial production and respiration. N and N+P co

  9. Delineation of groundwater development potential zones in parts of marginal Ganga Alluvial Plain in South Bihar, Eastern India.

    Science.gov (United States)

    Saha, Dipankar; Dhar, Y R; Vittala, S S

    2010-06-01

    A part of the Gangetic Alluvial Plain covering 2,228 km(2), in the state of Bihar, is studied for demarcating groundwater development potential zones. The area is mainly agrarian and experiencing intensive groundwater draft to the tune of 0.12 million cubic metre per square kilometres per year from the Quaternary marginal alluvial deposits, unconformably overlain northerly sloping Precambrian bedrock. Multiparametric data on groundwater comprising water level, hydraulic gradient (pre- and post-monsoon), aquifer thickness, permeability, suitability of groundwater for drinking and irrigation and groundwater resources vs. draft are spatially analysed and integrated on a Geographical Information System platform to generate thematic layers. By integrating these layers, three zones have been delineated based on groundwater development potential. It is inferred that about 48% of the area covering northern part has high development potential, while medium and low development potential category covers 41% of the area. Further increase in groundwater extraction is not recommended for an area of 173 km(2), affected by over-exploitation. The replenishable groundwater resource available for further extraction has been estimated. The development potential enhances towards north with increase in thickness of sediments. Local deviations are due to variation of-(1) cumulative thickness of aquifers, (2) deeper water level resulting from localised heavy groundwater extraction and (3) aquifer permeability.

  10. Effects of the Biofuels Initiative on Water Quality and Quantity in the Mississippi Alluvial Plain

    Science.gov (United States)

    Welch, H. L.; Green, C. T.; Coupe, R. H.

    2010-12-01

    In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The manifestation of the Biofuels Initiative in the Mississippi Delta was a 47-percent decrease in cotton acreage with a concurrent 288 percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation, this crop type change has implications for water quantity and quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged due to concerns about sustainability. A mathematical model calibrated to existing conditions in the Delta shows that increased fertilizer applications on corn will increase the extent of nitrate movement into the alluvial aquifer. Estimates based on surface-water modeling results indicate that higher application rates of nitrogen from increased corn production increases the amount of nitrogen exported from the Yazoo River basin to the Gulf of Mexico by about 7 percent; increasing the Delta’s contribution to hypoxic conditions in the Gulf of Mexico.

  11. Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone-Ganga alluvial tract in Middle Ganga Plain, India

    Science.gov (United States)

    Sahu, Sudarsan; Saha, Dipankar

    2014-08-01

    The basement of the Ganga basin in the Himalayan foreland is criss-crossed by several faults, dividing the basin into several sub-blocks forming horsts, grabens, or half-grabens. Tectonic perturbations along basement faults have affected the fluvial regime and extent of sediment fill in different parts of the basin during Late Quaternary. The East Patna Fault (EPF) and the West Patna Fault (WPF), located in Sone-Ganga alluvial tract in the southern marginal parts of Middle Ganga Plain (MGP), have remained tectonically active. The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and sedimentologic means) has revealed the existence of yet another fault within the half-graben, referred to as Bishunpur-Khagaul Fault (BKF). Many of the long profile morphological characters (e.g., knick-zone, low width-depth ratio) of the Sone River at its lower reaches can be ascribed to local structural deformation along BKF. These basement faults in MGP lie parallel to each other in NE-SW direction.

  12. Multiconfiguration electromagnetic induction survey for paleochannel internal structure imaging: a case study in the alluvial plain of the River Seine, France

    Science.gov (United States)

    Rejiba, Fayçal; Schamper, Cyril; Chevalier, Antoine; Deleplancque, Benoit; Hovhannissian, Gaghik; Thiesson, Julien; Weill, Pierre

    2018-01-01

    The La Bassée floodplain area is a large groundwater reservoir controlling most of the water exchanged between local aquifers and hydrographic networks within the Seine River basin (France). Preferential flows depend essentially on the heterogeneity of alluvial plain infilling, whose characteristics are strongly influenced by the presence of mud plugs (paleomeander clayey infilling). These mud plugs strongly contrast with the coarse sand material that composes most of the alluvial plain, and can create permeability barriers to groundwater flows. A detailed knowledge of the global and internal geometry of such paleomeanders can thus lead to a comprehensive understanding of the long-term hydrogeological processes of the alluvial plain. A geophysical survey based on the use of electromagnetic induction was performed on a wide paleomeander, situated close to the city of Nogent-sur-Seine in France. In the present study we assess the advantages of combining several spatial offsets, together with both vertical and horizontal dipole orientations (six apparent conductivities), thereby mapping not only the spatial distribution of the paleomeander derived from lidar data but also its vertical extent and internal variability.

  13. The groundwater balance in alluvial plain aquifer at Dehgolan, Kurdistan, Iran

    Science.gov (United States)

    Amini, Ata; Homayounfar, Vafa

    2017-10-01

    In this research, groundwater balance in Dehgolan plain, Kurdistan, Iran was carried out to assess changes in the level and volume of groundwater and water resources management. For this purpose, water resources supplies and consumption data, amount of charging and discharge and water level data recorded from wells and piezometers from 2010 to 2011 water year were gathered and analyzed. Rainfall and water losses of the study area were determined and required maps, including Iso-maps of the temperature, the evaporation, the groundwater level and the aquifer conductivity, were drawn by GIS software. Using the information and drawn maps and the equality of inputs and outputs data, the aquifer water balance was calculated. The results of balance equations showed that the balance is negative indicated a notably decline of groundwater equal to 15.029 million cubic meter (MCM). Such rate of decline is due to the large number of agricultural wells in the region, without considering the hydrological potential of the aquifer.

  14. A Hydrological Tomography Collocated with Time-varying Gravimetry for Hydrogeology -An Example in Yun-Lin Alluvial Plain and Ming-Ju Basin in Taiwan

    Science.gov (United States)

    Chen, K. H.; Cheng, C. C.; Hwang, C.

    2016-12-01

    A new inversion technique featured by the collocation of hydrological modeling and gravimetry observation is presented in this report. Initially this study started from a project attempting to build a sequence of hydrodynamic models of ground water system, which was applied to identify the supplement areas of alluvial plains and basins along the west coast of Taiwan. To calibrate the decent hydro-geological parameters for the modeling, geological evolution were carefully investigated and absolute gravity observations, along with other on-site hydrological monitoring data were specially introduced. It was discovered in the data processing that the time-varying gravimetrical data are highly sensitive to certain boundary conditions in the hydrodynamic model, which are correspondent with respective geological features. A new inversion technique coined by the term "hydrological tomography" is therefore developed by reversing the boundary condition into the unknowns to be solved. An example of accurate estimate for water storage and precipitation infiltration of a costal alluvial plain Yun-Lin is presented. In the mean time, the study of an anticline structure of the upstream basin Ming-Ju is also presented to demonstrate how a geological formation is outlined when the gravimetrical data and hydrodynamic model are re-directed into an inversion.

  15. Neolithic Occupation of Svratka Alluvial Plain; Case Study from Brno-Přízřenice, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Parma, D.; Vejrostová, L.; Lisá, Lenka; Bajer, A.; Pacina, J.; Gottwald, Z.

    2015-01-01

    Roč. 6, č. 2 (2015), s. 181-193 ISSN 1804-848X Institutional support: RVO:67985831 Keywords : alluvial zone * buried soils * prehistoric occupation * dark earth * geoarchaeology * micromorphology * grain size analysis * magnetic proxies Subject RIV: AC - Archeology, Anthropology, Ethnology http://www.iansa.eu/papers/IANSA-2015-02-parma.pdf

  16. Assessment of the chemical status of the alluvial aquifer in the Aosta Plain: an example of the implementation of the Water Framework Directive in Italy

    Science.gov (United States)

    Rotiroti, Marco; Fumagalli, Letizia; Stefania, Gennaro A.; Frigerio, Maria C.; Simonetto, Fulvio; Capodaglio, Pietro; Bonomi, Tullia

    2015-04-01

    The Italian Legislative Decree 30/09 (D.Lgs. 30/09) implements the EU Water Framework Directive (WFD) providing some technical guidelines to assess the chemical status of groundwater bodies. This work presents the estimation of the chemical status of the shallow aquifer in the Aosta Plain (Aosta Valley Region, NW Alpine sector, Italy) on the basis of the D.Lgs. 30/09. The study area covers ~40 km2 along the Dora Baltea River basin. The Aosta Plain hosts an alluvial aquifer formed of lacustrine, glacial, fluvio-glacial and fan deposits of Pleistocene and Holocene ages. The unconfined aquifer features a depth of ~80 m in the western part of the plain and ~20 in the eastern part due to the intercalation of a silty lacustrine layer. The aquifer is mainly recharged by precipitation, surface water and ice and snow melt. Previous studies revealed that SO4, Fe, Mn, Ni, Cr(VI) and PCE represent potential threats for groundwater quality in the Aosta Plain. The chemical status was calculated using the data collected during the 2012 by the Regional Environmental Protection Agency of the Aosta Valley Region from its groundwater quality monitoring network that includes 38 points. Each point was sampled up to four times. Since the D.Lgs. 30/09 excludes Fe and Mn from the assessment of the groundwater chemical status, the present work deals with SO4, Ni, Cr(VI) and PCE. Threshold values (TVs) were estimated on the basis of natural background levels (NBLs) for SO4, Ni and Cr(VI) whereas, for PCE, the reference value (REF) reported by the D.Lgs. 30/09 (i.e., 1.1 µg/L) was used as TV. The NBLs were calculated using the two approaches suggested by the EU research project BRIDGE, that are the pre-selection and the component separation. The TVs were evaluated using the following criteria: (a) if NBL pollution in the Aosta Plain in order to achieve the good chemical status as required by the WFD.

  17. {sup 210}Pb geochronology and chemical characterization of sediment cores from lakes of the Parana river alluvial plain

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, L.F.L.; Damatto, S.R.; Scapin, M.A. [IPEN - Instituto de Pesquisas Energeticas e Nucleares (Brazil); Remor, M.B.; Sampaio, S.C. [UNIOESTE - Universidade Estadual do Oeste do Parana (Brazil)

    2014-07-01

    The flood plain of the upper Parana River is located among the lakes formed by the Brazilian hydroelectric plants being the last part of the Parana river, in Brazil, where there is an ecosystem with interaction river-flood plain. This flood plain has considerable habitat variability, with great diversity of terrestrial and aquatic species, and the floods are the main factor that regulates the operation of this ecosystem. The seasonality of the flood pulses is mainly influenced by the El Nino phenomenon, which increases precipitation in the drainage basin of the flood plain of the upper Parana River. Because of its unique characteristics this ecosystem is the subject of intense study since 1980, mainly from the ecological point of view. Therefore, two sediment cores were collected in the ponds formed by the floods, Patos pond and Garcas pond, in order to characterize the sediment chemically and evaluate a possible historic contamination. The trace element concentrations As, Ba, Br, Ce, Co, Cr, Cs, Eu, Hf, La, Lu, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn (mg.kg{sup -1}) and the major elements Si, Al, Fe, Ti, K, Ca, Mg, P, V, Mn, and Na (%) were determined in the sediment cores dated by {sup 210}Pb method, using instrumental neutron activation analysis, X-ray fluorescence and gross beta counting, respectively. The results obtained for the elements Ce, Cr, Cs, La, Nd, Sc, Sm and Th are higher than the values of Upper Continental Crust for both ponds. The sedimentation rates obtained for Garca pond, 0.77 cm.y{sup -1}, and Patos pond, 0.62 cm.y{sup -1} are in agreement with studies performed in sedimentary environments similar to the present work, such as Brazilian wetland Pantanal. The enrichment factor and the geo-accumulation index were used to assess the presence of anthropogenic sources of pollution. Document available in abstract form only. (authors)

  18. Interception of residual nitrate from a calcareous alluvial soil profile on the North China Plain by deep-rooted crops: A {sup 15}N tracer study

    Energy Technology Data Exchange (ETDEWEB)

    Ju, X.T. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China)]. E-mail: juxt@cau.edu.cn; Gao, Q. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China); College of Agricultural Resources and Environmental Sciences, Jilin Agricultural University, Changchun 130118 (China); Christie, P. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Zhang, F.S. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100094 (China)

    2007-03-15

    {sup 15}N-labeled nitrate was injected into different depths of an alluvial calcareous soil profile on the North China Plain. Subsequent movement of NO{sub 3} {sup -}N and its recovery by deep-rooted maize (Zea mays L.) and shallow-rooted eggplant (Solanum melongena L.) were studied. Under conventional water and nutrient management the mean recoveries of {sup 15}N-labeled nitrate from K{sup 15}NO{sub 3} injected at depths 15, 45, and 75 cm were 22.4, 13.8, and 7.8% by maize and 7.9, 4.9, and 2.7% by eggplant. The recovery rate by maize at each soil depth was significantly higher than by eggplant. The deeper the injection of nitrate the smaller the distance of its downward movement and this corresponded with the movement of soil water during crop growth. Deeper rooting crops with high root length density and high water consumption may therefore be grown to utilize high concentrations of residual nitrate in the subsoil from previous intensive cropping and to protect the environment. - Deep-rooted crops have a greater capacity than shallow-rooted crops to intercept residual nitrate from the subsoil and restrict its movement down to the shallow groundw0010at.

  19. Interception of residual nitrate from a calcareous alluvial soil profile on the North China Plain by deep-rooted crops: A 15N tracer study

    International Nuclear Information System (INIS)

    Ju, X.T.; Gao, Q.; Christie, P.; Zhang, F.S.

    2007-01-01

    15 N-labeled nitrate was injected into different depths of an alluvial calcareous soil profile on the North China Plain. Subsequent movement of NO 3 - N and its recovery by deep-rooted maize (Zea mays L.) and shallow-rooted eggplant (Solanum melongena L.) were studied. Under conventional water and nutrient management the mean recoveries of 15 N-labeled nitrate from K 15 NO 3 injected at depths 15, 45, and 75 cm were 22.4, 13.8, and 7.8% by maize and 7.9, 4.9, and 2.7% by eggplant. The recovery rate by maize at each soil depth was significantly higher than by eggplant. The deeper the injection of nitrate the smaller the distance of its downward movement and this corresponded with the movement of soil water during crop growth. Deeper rooting crops with high root length density and high water consumption may therefore be grown to utilize high concentrations of residual nitrate in the subsoil from previous intensive cropping and to protect the environment. - Deep-rooted crops have a greater capacity than shallow-rooted crops to intercept residual nitrate from the subsoil and restrict its movement down to the shallow groundwater

  20. Effects of redox conditions on the control of arsenic mobility in shallow alluvial aquifers on the Venetian Plain (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Carraro, A. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy); Fabbri, P. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy); Department of Geosciences, University of Padova, 35131 Padova (Italy); Giaretta, A.; Peruzzo, L.; Tateo, F.; Tellini, F. [Institute of Geosciences and Earth Resources, National Research Council (CNR) of Italy, Padova, Italy c/o Department of Geosciences, University of Padova, 35131 Padova (Italy)

    2015-11-01

    The Venetian Plain is known for the occurrence of areas with high concentrations of arsenic in groundwater (greater than 400 μg/L). The study area represents the typical residential, industrial and agricultural features of most Western countries and is devoid of hydrothermal, volcanic or anthropogenic sources of arsenic. The aim of the study is to model the arsenic mobilization and the water–rock interaction by a complete hydrogeochemical investigation (analyses of filtered and unfiltered groundwater sediment mineralogy and geochemistry). The groundwater arsenic contamination and redox conditions are highly variable. Groundwaters with oxidizing and strongly reducing potentials have much lower arsenic concentrations than do mildly reducing waters. The grain size of the aquifer sediments includes gravels, sands and silty-clays. A continuous range of organic material concentrations is observed (from zero to 40%). The amount of sedimentary organic matter is highly correlated with the arsenic content of the sediments (up to 300 mg/kg), whereas no relationships are detectable between arsenic and other chemical parameters. The occurrence of arsenic minerals was observed as a peculiar feature under the scanning electron microscope. Arsenic and sulfur are the sole constituents of small tufts or thin crystals concentrated in small masses. These arsenic minerals were clearly observed in the peat sediments, in agreement with the geochemical modeling that requires very reducing conditions for their precipitation from the groundwater. The modeling suggests that, under oxidizing conditions, arsenic is adsorbed; moreover, a continuous decrease in the redox potential causes increasing desorption of arsenic. If the reducing conditions become more intense, the formation of As-S minerals would explain the lower concentration of arsenic measured in the strongly reducing groundwater. Even if As-sulfides are rare under low-temperature conditions, the anomalous abundance of reductants

  1. Effects of redox conditions on the control of arsenic mobility in shallow alluvial aquifers on the Venetian Plain (Italy)

    International Nuclear Information System (INIS)

    Carraro, A.; Fabbri, P.; Giaretta, A.; Peruzzo, L.; Tateo, F.; Tellini, F.

    2015-01-01

    The Venetian Plain is known for the occurrence of areas with high concentrations of arsenic in groundwater (greater than 400 μg/L). The study area represents the typical residential, industrial and agricultural features of most Western countries and is devoid of hydrothermal, volcanic or anthropogenic sources of arsenic. The aim of the study is to model the arsenic mobilization and the water–rock interaction by a complete hydrogeochemical investigation (analyses of filtered and unfiltered groundwater sediment mineralogy and geochemistry). The groundwater arsenic contamination and redox conditions are highly variable. Groundwaters with oxidizing and strongly reducing potentials have much lower arsenic concentrations than do mildly reducing waters. The grain size of the aquifer sediments includes gravels, sands and silty-clays. A continuous range of organic material concentrations is observed (from zero to 40%). The amount of sedimentary organic matter is highly correlated with the arsenic content of the sediments (up to 300 mg/kg), whereas no relationships are detectable between arsenic and other chemical parameters. The occurrence of arsenic minerals was observed as a peculiar feature under the scanning electron microscope. Arsenic and sulfur are the sole constituents of small tufts or thin crystals concentrated in small masses. These arsenic minerals were clearly observed in the peat sediments, in agreement with the geochemical modeling that requires very reducing conditions for their precipitation from the groundwater. The modeling suggests that, under oxidizing conditions, arsenic is adsorbed; moreover, a continuous decrease in the redox potential causes increasing desorption of arsenic. If the reducing conditions become more intense, the formation of As-S minerals would explain the lower concentration of arsenic measured in the strongly reducing groundwater. Even if As-sulfides are rare under low-temperature conditions, the anomalous abundance of reductants

  2. Alluvial Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — This coverage shows the extents of the alluvial aquifers in Kansas. The alluvial aquifers consist of unconsolidated Quaternary alluvium and contiguous terrace...

  3. Chemometric evaluation of heavy metal pollutions in Patna region of the Ganges alluvial plain, India: implication for source apportionment and health risk assessment.

    Science.gov (United States)

    Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra

    2018-03-28

    While metal pollution and distribution in soil are well documented for many countries, the situation is more serious in developing countries because of the rapid increase in industrialization and urbanization during last decades. Although it is well documented in developed countries, data about substantial metal pollution in Indian soil, especially in eastern Ganges alluvial plain (GAP), are limited. In this study, eight different blocks of Patna district located in eastern GAP were selected to investigate the contamination, accumulation, and sources of metals in surface soil considering different land use types. Additionally, human health risk assessment was estimated to mark the potential carcinogenic and non-carcinogenic effect of metals in soil. The concentration of all metals (except Pb) in soil was below the Indian standard limit of the potential toxic element for agricultural soil. Pb was the most abundant in soil, followed by Zn and Cu, and accounted for 52, 33 and 8% of the total metal. In terms of land use types, roadside soil detected higher concentrations of all metals, followed by park/grassland soil. Principal component analysis results indicated traffic pollution and industrial emissions are the major sources of heavy metals in soil. This was further confirmed by strong inter-correlation of heavy metals (Cd, Cr, Ni, Cu and Pb). Human health risk assessment results indicated ingestion via soil as the primary pathway of heavy metal exposure to both adults and children population. The estimated hazard index was highest for Pb, suggesting significant non-carcinogenic effect to both adults and children population. The children were more prone to the non-carcinogenic effect of Pb than adults. However, relatively low cancer risk value estimated for all metals suggested non-significant carcinogenic risk in the soil.

  4. Sedimentology, geochemistry and OSL dating of the alluvial succession in the northern Gujarat alluvial plain (western India) - A record to evaluate the sensitivity of a semiarid fluvial system to the climatic and tectonic forcing since the late Marine Isotopic Stage 3

    Science.gov (United States)

    Bhattacharya, Falguni; Shukla, Anil D.; Patel, R. C.; Rastogi, B. K.; Juyal, Navin

    2017-11-01

    The alluvial successions in the northern Gujarat alluvial plain (western India) have been investigated for reconstructing the climatic fluctuations during the last 40 ka. Alluvial architecture and geochemical proxies indicate prevalence of a strengthened Indian Summer Monsoon (ISM) with fluctuations between the late Marine Isotopic Stage 3 (MIS 3; 37 ka) to the early MIS 2 (27 ka). A gradual onset of aridity (declining ISM) after 27 ka with peak aridity at 22 ka is observed. A gradual strengthening of ISM at around 18 and > 12 ka followed by a short reversal in ISM intensity between 12 and 11 ka, is attributed to the Younger-Dryas (YD) cooling event. The aeolian sand sheet dated to 6 and 3.5 ka represents the onset of regional aridity. Following this, a short-lived humid phase was observed after 2 ka, which includes the Medieval Warm Period (MWP). The study suggests that the variability in the ISM to the latitudinal migration of the Inter Tropical Convergence Zone was caused by insolation-driven cooling and warming events in the North Atlantic. The incision of the valley fill alluvium occurred in two distinct phases. The older incision phase occurred after 11 ka and before 6 ka, whereas the younger incision phase that led to the development of present day topography is bracketed between 3.5 ka and before 1 ka. The older incision phase is ascribed to the early to mid-Holocene enhanced ISM (climatically driven), whereas the younger incision seems to be modulated by the activation of basement faults (tectonically driven).

  5. Statistical and Fractal Approaches on Long Time-Series to Surface-Water/Groundwater Relationship Assessment: A Central Italy Alluvial Plain Case Study

    Directory of Open Access Journals (Sweden)

    Alessandro Chiaudani

    2017-11-01

    Full Text Available In this research, univariate and bivariate statistical methods were applied to rainfall, river and piezometric level datasets belonging to 24-year time series (1986–2009. These methods, which often are used to understand the effects of precipitation on rivers and karstic springs discharge, have been used to assess piezometric level response to rainfall and river level fluctuations in a porous aquifer. A rain gauge, a river level gauge and three wells, located in Central Italy along the lower Pescara River valley in correspondence of its important alluvial aquifer, provided the data. Statistical analysis has been used within a known hydrogeological framework, which has been refined by mean of a photo-interpretation and a GPS survey. Water–groundwater relationships were identified following the autocorrelation and cross-correlation analyses. Spectral analysis and mono-fractal features of time series were assessed to provide information on multi-year variability, data distributions, their fractal dimension and the distribution return time within the historical time series. The statistical–mathematical results were interpreted through fieldwork that identified distinct groundwater flowpaths within the aquifer and enabled the implementation of a conceptual model, improving the knowledge on water resources management tools.

  6. Assessing the impacts of sea-level rise and precipitation change on the surficial aquifer in the low-lying coastal alluvial plains and barrier islands, east-central Florida (USA)

    Science.gov (United States)

    Xiao, Han; Wang, Dingbao; Hagen, Scott C.; Medeiros, Stephen C.; Hall, Carlton R.

    2016-11-01

    A three-dimensional variable-density groundwater flow and salinity transport model is implemented using the SEAWAT code to quantify the spatial variation of water-table depth and salinity of the surficial aquifer in Merritt Island and Cape Canaveral Island in east-central Florida (USA) under steady-state 2010 hydrologic and hydrogeologic conditions. The developed model is referred to as the `reference' model and calibrated against field-measured groundwater levels and a map of land use and land cover. Then, five prediction/projection models are developed based on modification of the boundary conditions of the calibrated `reference' model to quantify climate change impacts under various scenarios of sea-level rise and precipitation change projected to 2050. Model results indicate that west Merritt Island will encounter lowland inundation and saltwater intrusion due to its low elevation and flat topography, while climate change impacts on Cape Canaveral Island and east Merritt Island are not significant. The SEAWAT models developed for this study are useful and effective tools for water resources management, land use planning, and climate-change adaptation decision-making in these and other low-lying coastal alluvial plains and barrier island systems.

  7. Long-period amplification in deep alluvial basins and consequences for site-specific probabilistic seismic-hazard: the case of Castelleone in the Po Plain (Northern Italy)

    Science.gov (United States)

    Barani, S.; Mascandola, C.; Massa, M.; Spallarossa, D.

    2017-12-01

    The recent Emilia seismic sequence (Northern Italy) occurred at the end of the first half of 2012 with main shock of Mw6.1 highlighted the importance of studying site effects in the Po Plain, the larger and deeper sedimentary basin in Italy. As has long been known, long-period amplification related to deep sedimentary basins can significantly affect the characteristics of the ground-motion induced by strong earthquakes. It follows that the effects of deep sedimentary deposits on ground shaking require special attention during the definition of the design seismic action. The work presented here analyzes the impact of deep-soil discontinuities on ground-motion amplification, with particular focus on long-period probabilistic seismic-hazard assessment. The study focuses on the site of Castelleone, where a seismic station of the Italian National Seismic Network has been recording since 2009. Our study includes both experimental and numerical site response analyses. Specifically, extensive active and passive geophysical measurements were carried out in order to define a detailed shear-wave velocity (VS) model to be used in the numerical analyses. These latter are needed to assess the site-specific ground-motion hazard. Besides classical seismic refraction profiles and multichannel analysis of surface waves, we analyzed ambient vibration measurements in both single and array configurations. The VS profile was determined via joint inversion of the experimental phase-velocity dispersion curve with the ellipticity curve derived from horizontal-to-vertical spectral ratios. The profile shows two main discontinuities at depths of around 160 and 1350 m, respectively. The probabilistic site-specific hazard was assessed in terms of both spectral acceleration and displacement. A partially non-ergodic approach was adopted. We have found that the spectral acceleration hazard is barely sensitive to long-period (up to 10 s) amplification related to the deeper discontinuity whereas the

  8. Alluvial Deposits in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage maps alluvial deposits throughout Iowa. This generally would include areas of alluvial soils associated with modern streams that are identified on...

  9. Hidromorfía y condiciones ácuicas en suelos de la llanura aluvial de Tucumán (Argentina Hydromorphy and aquic conditions in soils of the alluvial plain of Tucumán (Argentina

    Directory of Open Access Journals (Sweden)

    Rodolfo Oscar Zappino

    2010-07-01

    Full Text Available Se seleccionaron cuatro perfiles de suelo con distinta clase de drenaje con el objetivo de analizar la intensidad del proceso de hidromorfía, y considerar cuáles cumplen con las condiciones ácuicas. Estos fueron: La Aguadita (Udipsamment típico, térmico, bien drenado, La Fronterita XI (Hapludol típico, franco grueso, illítico, térmico, moderadamente bien drenado, La Fronterita X (Argiudol ácuico, franco fino, illítico, térmico, imperfectamente drenado y Famaillá (Argiu-dol ácuico, fino, illítico, térmico, imperfectamente drenado. Los suelos muestran condiciones de endosaturación durante seis meses al año, con un ascenso del nivel freático durante verano-otoño y un descenso en invierno-primavera. La intensidad de la reducción se evaluó en base a la distribución de hierro y manganeso secundarios asociados a los rasgos redoximórficos identificados micromorfológicamente. En los perfiles bien drenados y moderadamente bien drenados, los Fe d y Mn d mostraron escasa movilidad con valores entre 0,50-0,80% y 0,03-0,06%, respectivamente, y rasgos redoximórficos de escaso desarrollo con un índice Mn/Fe d The profiles of four soils with different drainage types were selected in the alluvial plain of Tucumán in order to analyze the intensity of the hydromorphy and detect which of the soils conforms to an aquic conditions. The four types were: La Aguadita (thermic Typic Udipsamment (well-drained, La Fronterita XI (coarse loamy, illitic, thermic Typic Hapludoll (moderately well-drained, La Fronterita X (fine loamy, illitic, thermic Aquic Argiudoll (imperfectly drained, and Famaillá (fine, illitic, thermic Aquic Argiudoll (imperfectly drained. The soils show endosaturation conditions for six months of the year, with an increase in water level during summer-autumn and a decrease in winter-spring. The degree of reduction was assessed in terms of the distribution of iron and manganese associated with redoximorphic features analyzed on a

  10. Assessment of the denitrification process in alluvial wetlands at floodplain scale using the SWAT model

    Science.gov (United States)

    As alluvial plains support intensive agricultural activities, they often suffer from groundwater nitrate pollution. Denitrification is recognized as an important process in nitrate pollution control in riparian zones. In shallow aquifer zones influenced by recharged surface water, denitrification ...

  11. Case studies of groundwater- surface water interactions and scale relationships in small alluvial aquifers

    NARCIS (Netherlands)

    Love, Dave; de Hamer, Wouter; Owen, Richard J.S.; Booij, Martijn J.; Uhlenbrook, Stefan; Hoekstra, Arjen Ysbert; van der Zaag, Pieter

    2007-01-01

    An alluvial aquifer can be described as a groundwater system, generally unconfined, that is hosted in laterally discontinuous layers of gravel, sand, silt and clay, deposited by a river in a river channel, banks or flood plain. In semi-arid regions, streams that are associated with alluvial aquifers

  12. Outlook for Mississippi Alluvial Valley forests: a subregional report from the Southern Forest Futures Project

    Science.gov (United States)

    Emile S. Gardiner

    2015-01-01

    The Mississippi Alluvial Valley, which can be broadly subdivided into the Holocene Deposits section and the Deltaic Plain section, is a 24.9-million-acre area generally approximating the alluvial floodplain and delta of the lower Mississippi River. Its robust agricultural economy is maintained by a largely rural population, and recreational resources draw high...

  13. Laboratory alluvial fans in one dimension.

    Science.gov (United States)

    Guerit, L; Métivier, F; Devauchelle, O; Lajeunesse, E; Barrier, L

    2014-08-01

    When they reach a flat plain, rivers often deposit their sediment load into a cone-shaped structure called alluvial fan. We present a simplified experimental setup that reproduces, in one dimension, basic features of alluvial fans. A mixture of water and glycerol transports and deposits glass beads between two transparent panels separated by a narrow gap. As the beads, which mimic natural sediments, get deposited in this gap, they form an almost one-dimensional fan. At a moderate sediment discharge, the fan grows quasistatically and maintains its slope just above the threshold for sediment transport. The water discharge determines this critical slope. At leading order, the sediment discharge only controls the velocity at which the fan grows. A more detailed analysis reveals a slight curvature of the fan profile, which relates directly to the rate at which sediments are transported.

  14. Fertilizers mobilization in alluvial aquifer: laboratory experiments

    Science.gov (United States)

    Mastrocicco, M.; Colombani, N.; Palpacelli, S.

    2009-02-01

    In alluvial plains, intensive farming with conspicuous use of agrochemicals, can cause land pollution and groundwater contamination. In central Po River plain, paleo-channels are important links between arable lands and the underlaying aquifer, since the latter is often confined by clay sediments that act as a barrier against contaminants migration. Therefore, paleo-channels are recharge zones of particular interest that have to be protected from pollution as they are commonly used for water supply. This paper focuses on fertilizer mobilization next to a sand pit excavated in a paleo-channel near Ferrara (Italy). The problem is approached via batch test leaking and columns elution of alluvial sediments. Results from batch experiments showed fast increase in all major cations and anions, suggesting equilibrium control of dissolution reactions, limited availability of solid phases and geochemical homogeneity of samples. In column experiments, early elution and tailing of all ions breakthrough was recorded due to preferential flow paths. For sediments investigated in this study, dispersion, dilution and chemical reactions can reduce fertilizers at concentration below drinking standards in a reasonable time frame, provided fertilizer loading is halted or, at least, reduced. Thus, the definition of a corridor along paleo-channels is recommended to preserve groundwater quality.

  15. Variabilidade espacial de classes de textura, salinidade e condutividade hidráulica de solos em planície aluvial Spatial variability of textural classes, salinity and hydraulic conductivity of soil in an alluvial plain

    Directory of Open Access Journals (Sweden)

    Abelardo A. A. Montenegro

    2006-03-01

    Full Text Available Visando-se avaliar a distribuição de classes texturais e sua correlação espacial com a infiltrabilidade e salinidade de uma área aluvial, no Agreste de Pernambuco, utilizou-se a geoestatística indicadora segundo uma distribuição binária baseada na presença/ausência de solos francos. Considerando-se pontos de amostragem e de testes de infiltração dispostos ao longo do eixo principal do aluvião, e aleatoriamente distribuídos, analisou-se a variabilidade espacial das classes de solo predominantes, da velocidade de infiltração básica (condutividade hidráulica saturada e da condutividade elétrica do extrato de saturação da camada subsuperficial, cujos alcances dos semi-variogramas ajustados foram de 333, 320 e 520 m, respectivamente. Verificou-se que a geoestatística indicadora preservou a correlação espacial entre a textura e a condutividade hidráulica, e entre a textura e a condutividade elétrica. Deste modo, as classes de solo predominantes podem ser usadas para representar distintos padrões no tocante ao potencial de lixiviação e à susceptibilidade de salinização. A metodologia indicadora mostra-se promissora para estudo da variabilidade espacial de propriedades físicas de solos aluviais onde predominam classes contrastantes.Aiming to evaluate the soil textural classes distribution and the spatial correlation between the soil textural classes and both infiltration rate and salinity in an alluvial area, in Pernambuco State "agreste" region, indicator geostatistics has been applied, adopting a binary distribution based on the presence/absence of loam soils. Considering sampling points and test locations along the main longitudinal transect in the valley, as well as randomly distributed locations, the spatial variability of the main soil classes, the infiltration rate, and the electrical conductivity of the saturated extract have been analyzed, for the subsurface soil layer. The fitted semivariogram ranges were 333

  16. Alluvial aquifers in the Mzingwane catchment: Their distribution, properties, current usage and potential expansion

    Science.gov (United States)

    Moyce, William; Mangeya, Pride; Owen, Richard; Love, David

    The Mzingwane River is a sand filled channel, with extensive alluvial aquifers distributed along its banks and bed in the lower catchment. LandSat TM imagery was used to identify alluvial deposits for potential groundwater resources for irrigation development. On the false colour composite band 3, band 4 and band 5 (FCC 345) the alluvial deposits stand out as white and dense actively growing vegetation stands out as green making it possible to mark out the lateral extent of the saturated alluvial plain deposits using the riverine fringe and vegetation . The alluvial aquifers form ribbon shaped aquifers extending along the channel and reaching over 20 km in length in some localities and are enhanced at lithological boundaries. These alluvial aquifers extend laterally outside the active channel, and individual alluvial aquifers have been measured with area ranging from 45 ha to 723 ha in the channels and 75 ha to 2196 ha on the plains. The alluvial aquifers are more pronounced in the Lower Mzingwane, where the slopes are gentler and allow for more sediment accumulation. Estimated water resources potential ranges between 175,000 m 3 and 5,430,000 m 3 in the channels and between 80,000 m 3 and 6,920,000 m 3 in the plains. Such a water resource potential can support irrigation ranging from 18 ha to 543 ha for channels alluvial aquifers and 8 ha to 692 ha for plain alluvial aquifers. Currently, some of these aquifers are being used to provide water for domestic use, livestock watering and dip tanks, commercial irrigation and market gardening. The water quality of the aquifers in general is fairly good due to regular recharge and flushing out of the aquifers by annual river flows and floodwater. Water salinity was found to increase significantly in the end of the dry season, and this effect was more pronounced in water abstracted from wells on the alluvial plains. During drought years, recharge is expected to be less and if the drought is extended water levels in the

  17. Radiocarbon dating of sediment cores from Hachinohe, the Kamikita Plain

    International Nuclear Information System (INIS)

    Hitoki, Eri; Nakamura, Toshio; Matsumoto, Yui; Tsuji, Sei-ichiro; Fujine, Hisashi

    2013-01-01

    We investigated stratigraphy and chronology by analyses of Holocene sediments and radiocarbon dating of sediment cores from the Kamikita Plain. On the Kamikita Plain, which faces the Pacific coast of Northeast Japan, marine and fluvial terraces covered with tephras derived from Towada and Hakkoda volcanoes are well developed. We clarified that Towada Chuseri tephra and fluvial deposits consisted of volcanic sediments influenced an alluvial depositional system in the Kamikita Plain after a maximum of the Jomon Transgression. (author)

  18. Characterisation of the Ionian-Lucanian coastal plain aquifer

    OpenAIRE

    Polemio, M.; Limoni, P.P.; Mitolo, D.; Santaloia, F.

    2002-01-01

    This paper deals with a Southern Italy area, 40 km by 10 km wide, located where four river valleys anastomose themselves in the coastal plain. The geological and hydrogeological features of the study area and the chemical-physical groundwater characterisation have been inferred from the data analysis of 1130 boreholes. Some aquifers, connected among them, constituted by soils of different geological origin -marine terraces deposits, river valley alluvial deposits and alluvial and coastal depo...

  19. Geological aspects of paleoseismicity and archaeosismology in the fluvial alluvial Rimac valley

    OpenAIRE

    Jacay, Javier

    2017-01-01

    The sedimentary fill of the Rimac River fluvial-alluvial plain (Upper Miocene-Quaternary) consists of a thick sequence of unconsolidated material that corresponds to fluvial deposits. A record of seismotectonic activity is presentedin the sedimentary levels of fine facie within numerous paleoseismic structures such as contoured layers, pseudonodules, load figures, and material injections. Additionally, wall inclination and collapse, as well as displacement and partialfracturing, and pavement ...

  20. Response spectra in alluvial soils

    International Nuclear Information System (INIS)

    Chandrasekharan, A.R.; Paul, D.K.

    1975-01-01

    For aseismic design of structures, the ground motion data is assumed either in the form of ground acceleration as a function of time or indirectly in the form of response spectra. Though the response spectra approach has limitations like not being applicable for nonlinear problems, it is usually used for structures like nuclear power plants. Fifty accelerograms recorded at alluvial sites have been processed. Since different empirical formulas relating acceleration with magnitude and distance give a wide scatter of values, peak ground acceleration alone cannot be the parameter as is assumed by a number of authors. The spectra corresponding to 5% damping have been normalised with respect to three parameters, namely, peak ground acceleration, peak ground velocity and a nondimensional quantity ad/v 2 . Envelopee of maxima and minima as well as average response spectra has been obtained. A comparison with the USAEC spectra has been made. A relation between ground acceleration, ground velocity and ad/v 2 has been obtained which would nearly give the same magnification of the response. A design response spectra for alluvial soils has been recommended. (author)

  1. Controls on alluvial fans morphology

    Science.gov (United States)

    Delorme, P.; Devauchelle, O.; Lajeunesse, E.; Barrier, L.; Métivier, F.

    2017-12-01

    Using laboratory experiments, we investigate the influence of water and sediment discharges on the morphology of an alluvial fan. In our flume, a single-thread laminar river deposits corundum sand (0.4 mm) into a conical fan. We record the fan progradation with top-view images, and measure its shape using the deformation of a Moiré pattern. The fan remains virtually self-affine as it grows, with a nearly constant slope. We find that, when the sediment discharge is small, the longitudinal slope of the fan remains close to that of a river at the threshold for sediment transport. A higher sediment discharge causes the fan's slope to depart from the threshold value. Due to the downstream decrease of the sediment load, this slope gets shallower towards the fan's toe. This mechanism generates a slightly concave fan profile. This suggests that the proximal slope of an alluvial fan could be a proxy for the sediment flux that feeds the fan.Finally, we discuss the applicability of these results to natural systems.

  2. Utopia Plain

    Science.gov (United States)

    2006-01-01

    5 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dark-toned, cratered plain in southwest Utopia Planitia. Large, light-toned, windblown ripples reside on the floors of many of the depressions in the scene, including a long, linear, trough. Location near: 30.3oN, 255.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  3. Estimation of alluvial recharge in the semiarid

    OpenAIRE

    Andrade,Tafnes S.; Montenegro,Suzana M. G. L.; Montenegro,Abelardo A. de A.; Rodrigues,Diogo F. B.

    2014-01-01

    In areas where there is irrigated agriculture, the recuperation of water reserves in alluvial aquifers may occur preferentially due to precipitation. Recharging can be evaluated from variation information of water depth measured in piezometers or observation wells. Thus, the aim of this research is to study the recharge in the alluvial aquifer formed by the Mimoso temporary stream in the semiarid region of Pernambuco (PE), Brazil, using the method of the fluctuation of the water level. This s...

  4. Isotope studies on mechanisms of groundwater recharge to an alluvial aquifer in Gatton, Queensland, Australia

    International Nuclear Information System (INIS)

    Dharmasiri, J.K.; Morawska, L.

    1997-01-01

    Gatton is an important agricultural area for Queensland where about 40% of its vegetables needs are produced using groundwater as the main source. An alluvial Aquifer is located about 30m beneath the layers of alluvial sediments ranging from black soils of volcanic origin on top, layers of alluvial sands, clays and beds of sand and gravel. The leakage of creek flows has been considered to be the main source of recharge to this aquifer. A number of weirs have been built across the Lockyer and Laidley creeks to allow surface water to infiltrate through the beds when the creeks flow. Water levels in bores in a section located in the middle of the alluvial plain (Crowley Vale) have been declining for the last 20 years with little or no success in recharging from the creeks. Acute water shortages have been experienced in the Gatton area during the droughts of 1980-81, 1986-87 and 1994-97. Naturally occurring stable isotopes, 2 H, 18 0 and 13 C as well as radioisotopes 3 H and 14 C have been used to delineate sources of recharge and active recharge areas. Tritium tracing of soil moisture in the unsaturated soil was also used to determine direct infiltration rates

  5. Adsorption behavior of endosulfan on alluvial soil

    International Nuclear Information System (INIS)

    Ashraf, M.; Sherazi, S.T.H.; Nizamani, S.M.; Bhanger, M.I.

    2012-01-01

    The present study was carried out to assess the behavior of endosulfan pesticide in alluvial soil under laboratory conditions. Sandy loam soil was studied to evaluate the fate of applied endosulfan with respect to soil properties. Known amount of endosulfan was added on alluvial soil in PVC column and eluted with 1000 ml of water. Eluents were collected in 10 parts, each of 100 ml. The soil in the column was divided in to three equal parts, each of 10 cm. Each part of the soil and eluents were analyzed for the determination of Endosulfan level using GC- mu ECD and GC-MS techniques. The kinetic and equilibrium adsorption characteristics of endosulfan on sandy loam soil was also studied and found that it follows Ho's pseudo second order and Freundlich isotherm. The present study revealed that a-and beta-Endosulfan was determined efficiently with their degraded products in alluvial soil under laboratory conditions with above mentioned instruments. (author)

  6. Quaternary alluvial stratigraphy and palaeoclimatic reconstruction at the Thar margin

    DEFF Research Database (Denmark)

    Jain, M.; Tandon, S.K.

    2003-01-01

    Quaternary alluvial record at the Thar desert margin has been examined using the exposed succession along Mahudi, Sabarmati river, Western India. Different alluvial facies, their associations and granulometry have been studied for palaeoenvironmental reconstruction. Clay mineral indices smectite/...

  7. The Quaternary alluvial systems tract of the Pantanal Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Mario Luis Assine

    Full Text Available ABSTRACT The Pantanal Basin is an active sedimentary basin in central-west Brazil that consists of a complex alluvial systems tract characterized by the interaction between different river systems developed in one of the largest wetlands in the world. The Paraguay River is the trunk river system that drains the water and part of the sediment load received from areas outside of the basin. Depositional styles vary considerably along the river profiles throughout the basin, with the development of entrenched meandering belts, anastomosing reaches, and floodplain ponds. Paleodrainage patterns are preserved on the surface of abandoned lobes of fluvial fans, which also exhibit many degradational channels. Here, we propose a novel classification scheme according to which the geomorphology, hydrological regime and sedimentary dynamics of these fluvial systems are determined by the geology and geomorphology of the source areas. In this way, the following systems are recognized and described: (I the Paraguay trunk-river plains; (II fluvial fans sourced by the tablelands catchment area; (III fluvial fans sourced by lowlands; and (IV fluvial interfans. We highlight the importance of considering the influences of source areas when interpreting contrasting styles of fluvial architectures in the rock record.

  8. Turkana Grits - a Cretaceous braided alluvial system in northern Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Handford, C.R.

    1987-05-01

    Rather spotty but excellent exposures of the Cretaceous-age Turkana Grits occur near the western shore of Lake Turkana, northern Kenya. These very coarse to pebbly arkosic sandstones and sandy conglomerates were derived from and rest unconformably upon Precambrian metamorphic basement; they are overlain by late Tertiary basaltic flows that comprise much of the volcanics in the East African Rift Zone. The formation ranges up to 2000 ft thick in the Laburr Range. Several outcrops contain sauropod, crocodile, and tortoise remains as well as abundant trunks of petrified wood (Dryoxylon). Five major facies make up the Turkana Grits and record a major episode of continental fluvial deposition in basins flanked by Precambrian basement. Facies 1 is crudely stratified, cobble and boulder conglomerate (clast-supported); Facies 2 is crudely stratified pebble-cobble conglomerate and pebbly sandstone; Facies 3 is trough cross-bedded, very coarse sandstones containing fossils wood and vertebrate remains; Facies 4 is crudely stratified to massive sandstones with ironstone nodules; and Facies 5 is red, purple, and gray mudstone and mud shale with carbonate nodules. Facies 1 through 3 record deposition in proximal to medial braided-stream channel, longitudinal bar and dune complexes. Facies 4 is a lowland, hydromorphic paleosol, and Facies 5 represents overbank and abandoned channel-fill sedimentation in an alluvial plain.

  9. A distribution of adsorbed forms of cesium 137 and strontium 90 in flood-plain formations of Sozh river

    International Nuclear Information System (INIS)

    Kuznetsov, V.A.; Generalova, V.A.

    1999-01-01

    The distribution of strontium 90 and cesium 137 forms in flood-plain geochemical system 'alluvial deposits - flood-plain turf - humus horizon - soil-source rock', where sorption and colloidal processes play main role in the isotopes migration, was studied. The bulk amount of strontium 90 is presented in adsorbed form in all investigated objects, whereas only 6% of cesium 137 amount in alluvial deposits, flood-plain turf and humus horizon is in adsorbed form. The content of exchange forms of cesium 137 and strontium 90 increases with the depth of the layer. The race of this increase for strontium 90 is large than for cesium 137. The distribution of radionuclides through the different parts of flood-plain of Sozh river has some distinctions due to more lability of adsorbed strontium 90 forms in comparison with cesium 137 ones

  10. An Alluvial Fan at Apollinaris Patera, Mars

    OpenAIRE

    Ghail, RC; Hutchison, JE

    2003-01-01

    Apollinaris Patera, Mars (7?S,173?E), is an intermediate sized volcano (~6 km high, 150 km diameter) with a large (200-km long) fan-like deposit on its southern flank. This fan is deeply incised and originates from a single breach in the rim of the summit caldera. New topographic and multispectral image data reveal that this fan is alluvial, implying a long-lived source of (volcaniclastic) sediment and water (probably from a caldera lake).

  11. Interaction of fine sediment with alluvial streambeds

    Science.gov (United States)

    Jobson, Harvey E.; Carey, William P.

    1989-01-01

    More knowledge is needed about the physical processes that control the transport of fine sediment moving over an alluvial bed. The knowledge is needed to design rational sampling and monitoring programs that assess the transport and fate of toxic substances in surface waters because the toxics are often associated with silt- and clay-sized particles. This technical note reviews some of the past research in areas that may contribute to an increased understanding of the processes involved. An alluvial streambed can have a large capacity to store fine sediments that are extracted from the flow when instream concentrations are high and it can gradually release fine sediment to the flow when the instream concentrations are low. Several types of storage mechanisms are available depending on the relative size distribution of the suspended load and bed material, as well as the flow hydraulics. Alluvial flow tends to segregate the deposited material according to size and density. Some of the storage locations are temporary, but some can store the fine sediment for very long periods of time.

  12. Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

    Directory of Open Access Journals (Sweden)

    Wotchoko Pierre

    2016-07-01

    Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

  13. CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.

    Science.gov (United States)

    Simon, Andrew; Hupp, Cliff R.

    1987-01-01

    This study (a) assesses the channel changes and network trends of bed level response after modifications between 1959 and 1972 of alluvial channels in western Tennessee and (b) develops a conceptual model of bank slope development to qualitatively assess bank stability and potential channel widening. A six-step, semiquantitative model of channel evolution in disturbed channels was developed by quantifying bed level trends and recognizing qualitative stages of bank slope development. Development of the bank profile is defined in terms of three dynamic and observable surfaces: (a) vertical face (70 to 90 degrees), (b) upper bank (25 to 50 degrees), and (c) slough line (20 to 25 degrees).

  14. Buried paleoindian-age landscapes in stream valleys of the central plains, USA

    Science.gov (United States)

    Mandel, R.D.

    2008-01-01

    A systematic study of late-Quaternary landscape evolution in the Central Plains documented widespread, deeply buried paleosols that represent Paleoindian-age landscapes in terrace fills of large streams (> 5th order), in alluvial fans, and in draws in areas of western Kansas with a thick loess mantle. Alluvial stratigraphic sections were investigated along a steep bio-climatic gradient extending from the moist-subhumid forest-prairie border of the east-central Plains to the dry-subhumid and semi-arid shortgrass prairie of the west-central Plains. Radiocarbon ages indicate that most large streams were characterized by slow aggradation accompanied by cumulic soil development from ca. 11,500 to 10,000??14C yr B.P. In the valleys of some large streams, such as the Ninnescah and Saline rivers, these processes continued into the early Holocene. The soil-stratigraphic record in the draws of western Kansas indicates slow aggradation punctuated by episodes of landscape stability and pedogenesis beginning as early as ca. 13,300??14C yr B.P. and spanning the Pleistocene-Holocene boundary. The development record of alluvial fans in western Kansas is similar to the record in the draws; slow aggradation was punctuated by multiple episodes of soil development between ca. 13,000 and 9000??14C yr B.P. In eastern Kansas and Nebraska, development of alluvial fans was common during the early and middle Holocene, but evidence shows fan development as early as ca. 11,300??14C yr B.P. Buried soils dating between ca. 12,600 and 9000??14C yr B.P. were documented in fans throughout the region. In stream valleys across the Central Plains, rapid alluviation after ca. 9000??14C yr B.P. resulted in deeply buried soils that may harbor Paleoindian cultural deposits. Hence, the paucity of recorded stratified Paleoindian sites in the Central Plains is probably related to poor visibility (i.e., deep burial in alluvial deposits) instead of limited human occupation in the region during the terminal

  15. Quantifying relief on alluvial fans using airborne lidar to reveal patterns of sediment accumulation

    Science.gov (United States)

    Morelan, A. E., III; Oskin, M. E.

    2017-12-01

    We present a method of quantifying detailed surface relief on alluvial fans from high-resolution topography. Average slope and curvature of the fan are used together to empirically derive an idealized, radially symmetric fan surface, from which we compute residual topography. Maps produced using this technique highlight spatial patterns of fan deposition and avulsion. Regions of high residual topography reveal active and abandoned sediment lobes accumulated from recent depositional events, often with well-defined channels at their apex. Preliminary observations suggest that surface relief is uniform across a collection of fans in a given region and source lithology. Alluvial fans with granitic catchment lithologies in eastern California (n=12), each with varying source catchment size and mean fan slope, all show relief of around 4 meters. A collection of fans from the Carrizo Plain in central California (n=12), with source catchments set within Miocene marine and nonmarine sedimentary rocks, show significantly lower relief values around 2 meters. We hypothesize that particle grain size determines this contrasting relief through its control on the thickness of fan-building debris flows. In both settings we find that sediment lobes tend to extend toward the fan toe. This pattern supports a process, observed in analog experiments, of fan deposition dominated by back-filling and overtopping of distributary channels by debris-flows.

  16. Luminescence dating of paleoseismic events associated with the Muzaffarnagar fault in the Western Gangetic Plain

    International Nuclear Information System (INIS)

    Bhosle, Balaji; Parkash, B.; Awasthi, A.K.

    2006-01-01

    Using remote sensing and GIS techniques of satellite data processing, Muzaffarnagar fault is identified in western Gangetic Plain. Activity along the fault has resulted in deposition of colluvial deposits (alluvial fans) on the downthrown block. Luminescence dating of colluvial deposits suggests that the fault is segmented. The last activity which took place along the eastern segment was at 3.5 ka and middle and western segment were active during 2.5-2.8 ka. (author)

  17. Evaluation of carbaryl sorption in alluvial soil

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal

    2013-12-01

    Full Text Available This study investigated the adsorption potential of carbaryl onto alluvial soil. Parameters that influence the adsorption process such as pH, adsorbent dose, initial carbaryl concentration, stirring rate, particle size, contact time and temperature were studied in a batch process. The carbaryl adsorption capacity was at maximum at pH 6 for an initial concentration of 20 ppm. Adsorption equilibirium time was observed in 180 min. Equilibrium adsorption data was best fitted with Freundlich isotherm and pseudo-first order kinetic model, respectively. The adsorbent was characterized by X-ray diffraction spectrum, Fourier transform infrared spectroscopy and scanning electron microscopy. The experiment performed indicated that the adsorption capacity of carbaryl was significantly correlated with particle size, organic matter and pH of the soil. Therefore, the possibility for carbaryl to contaminate underground water may be greater in the presence of low organic matter content.

  18. Environmental isotope study related to groundwater age, flow system and saline water origin in Quaternary aquifers of North China Plain

    International Nuclear Information System (INIS)

    Zhang Zhigan; Payne, B.R.

    1988-01-01

    An isotopic hydrology section across the North China Plain has been studied to investigate problems of groundwater age, flow system and saline water origin in a semi-arid pre-mountain artesian basin. Two local and one regional flow system along the section have been recognized. Turnover time of water for alluvial fan, shallow and regional systems are estimated to be the order of 10 2 , 10 3 , and 10 4 years respectively. Specific flow rates for the three systems have been calculated. Only less than 5 percent of flow from alluvial fan is drained by the regional flow system and the rest, in natural conditions, discharges at surface in the front edge of an alluvial fan and forms a groundwater discharge belt at a good distance away from the mountain foot. Developed in the alluvial plain and coastal plain areas the shallow flow system embraces a series of small local systems. Groundwater in these systems appears to be the salt carrier during continental salinization. It washes salt out of the recharge area and deep-occurred strata by circulating and carries it up to the surface in lowland areas. Consequently, in parallel with salinization at surface a desalinization process occurs at depth, which provides an additional explanation for the existing thick deep fresh water zone in most arid and semi-arid regions, where continental salting process is in progress. (author). 6 refs, 8 figs, 4 tabs

  19. The limnology of a Mississippi River alluvial plain oxbow lake following the application of conservation practices

    Science.gov (United States)

    From 1995 and 2011 Beasley Lake watershed near Indianola, MS, was subjected to a variety of conservation measures designed to reduce water velocity, erosion and discharge of sediment laden water. Water quality monitoring during the period indicated a number of long term trends and relationships bet...

  20. The pre- and protohistoric togué of the Niger alluvial plain, Mali

    NARCIS (Netherlands)

    Schmidt, Annette Margaretha

    2009-01-01

    The Inland Niger Delta in Mali is scattered with thousands of tell-like dwelling mounds that testify to the rich archaeological heritage of this attractive occupation area. Little is known about the structure and evolution of this considerable settlement system. The general aim of the present

  1. Improved simulation of river water and groundwater exchange in an alluvial plain using the SWAT model

    Science.gov (United States)

    Hydrological interaction between surface and subsurface water systems has a significant impact on water quality, ecosystems and biogeochemistry cycling of both systems. Distributed models have been developed to simulate this function, but they require detailed spatial inputs and extensive computati...

  2. Confirmation of a theory: reconstruction of an alluvial plain development in a flume experiment

    Czech Academy of Sciences Publication Activity Database

    Bertalan, L.; Tóth, C. A.; Szabó, G.; Nagy, G.; Kuda, František; Szabó, S.

    2016-01-01

    Roč. 70, č. 3 (2016), s. 271-285 ISSN 0014-0015 Institutional support: RVO:68145535 Keywords : fluvial geomorphology * flume experiment * avulsion Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.923, year: 2016

  3. Design of flood protection for transportation alignments on alluvial fans

    International Nuclear Information System (INIS)

    French, R.H.

    1991-01-01

    The method of floodplain delineation on alluvial fans developed for the national flood insurance program is modified to provide estimates of peak flood flows at transportation alignments crossing an alluvial fan. The modified methodology divides the total alignment length into drainage design segments and estimates the peak flows that drainage structures would be required to convey as a function of the length of the drainage design segment, the return period of the event, and the location of the alignment on the alluvial fan. An example of the application of the methodology is provided. 16 refs., 5 figs

  4. Radon concentration in the springs of the alluvial fan

    International Nuclear Information System (INIS)

    Horiuchi, Kimiko; Ishii, Tadashi; Kobayashi, Masao

    2003-01-01

    Rokugo alluvial fan is one of the typical stratified alluvial fans which have grown in the east edge of Yokote basin in Akita Prefecture. Many of Rokugo's springs are gushing out from 45 m to 50 m above the sea level where city town have been developed. Mechanism of gushing out of spring is closely bound up with the landform of this area. There is nearly no radon existing in the surface water, but in groundwater, radon concentrations are stable in every stratums and infiltration of groundwater to surface water. We would like to obtain some hydrological information by measuring radon concentration in water samples of Rokugo alluvial fan. (author)

  5. The Plains of Venus

    Science.gov (United States)

    Sharpton, V. L.

    2013-12-01

    Volcanic plains units of various types comprise at least 80% of the surface of Venus. Though devoid of topographic splendor and, therefore often overlooked, these plains units house a spectacular array of volcanic, tectonic, and impact features. Here I propose that the plains hold the keys to understanding the resurfacing history of Venus and resolving the global stratigraphy debate. The quasi-random distribution of impact craters and the small number that have been conspicuously modified from the outside by plains-forming volcanism have led some to propose that Venus was catastrophically resurfaced around 725×375 Ma with little volcanism since. Challenges, however, hinge on interpretations of certain morphological characteristics of impact craters: For instance, Venusian impact craters exhibit either radar dark (smooth) floor deposits or bright, blocky floors. Bright floor craters (BFC) are typically 100-400 m deeper than dark floor craters (DFC). Furthermore, all 58 impact craters with ephemeral bright ejecta rays and/or distal parabolic ejecta patterns have bright floor deposits. This suggests that BFCs are younger, on average, than DFCs. These observations suggest that DFCs could be partially filled with lava during plains emplacement and, therefore, are not strictly younger than the plains units as widely held. Because the DFC group comprises ~80% of the total crater population on Venus the recalculated emplacement age of the plains would be ~145 Ma if DFCs are indeed volcanically modified during plains formation. Improved image and topographic data are required to measure stratigraphic and morphometric relationships and resolve this issue. Plains units are also home to an abundant and diverse set of volcanic features including steep-sided domes, shield fields, isolated volcanoes, collapse features and lava channels, some of which extend for 1000s of kilometers. The inferred viscosity range of plains-forming lavas, therefore, is immense, ranging from the

  6. Wind measurement on the Linth plain; Windmessung in der Linthebene

    Energy Technology Data Exchange (ETDEWEB)

    Langraf, B.

    2003-07-01

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of wind measurements made on the Linth plain, a flat alluvial plain in eastern Switzerland located between mountain ranges. The data, which were collected using temporary measurement masts at two locations are presented in the form of tables, diagrams and maps showing the wind-energy potential of various areas of the plain. The actual measurements are compared with prognoses from a geo-information system. The wind measurement equipment and installations are described, as are the software models for the calculation of wind direction, wind intensity and of a prognosis for energy production. Particular attention was also paid to the question of wind turbulence. Further factors investigated included the possibility of icing-up in winter and the choice of a meteorological station in the neighbourhood with similar characteristics that could be used as a reference station. The report also presents the results of the evaluation of various possible locations for wind turbines on the Linth plain. Visual, noise and shadow-casing factors are considered.

  7. Water transport in desert alluvial soil

    International Nuclear Information System (INIS)

    Kearl, P.M.

    1982-04-01

    Safe storage of radioactive waste buried in an arid alluvial soil requires extensive site characterization of the physical process influencing moisture movement which could act as a transport medium for the migration of radionuclides. The field portion of this study included an infiltration plot instrumented with thermocouple psychrometers and neturon moisture probe access holes. Baseline information shows a zone of higher moisture content at approximately 1.5 m (5 ft) in depth. A sprinkler system simulated a 500-year precipitation event. Results revealed water penetrated the soil to 0.9 m (2.9 ft). Due to the low moisture content, vapor transport was primarily responsible for water movement at this depth. Temperature gradients are substantially responsible for vapor transport by preferentially sorting water-vapor molecules from the surrounding air by using the soil as a molecular sieve. Adsorbed and capillary water vapor pressure increases in response to a temperature increase and releases additional water to the soil pore atmosphere to be diffused away

  8. Designing the Alluvial Riverbeds in Curved Paths

    Science.gov (United States)

    Macura, Viliam; Škrinár, Andrej; Štefunková, Zuzana; Muchová, Zlatica; Majorošová, Martina

    2017-10-01

    The paper presents the method of determining the shape of the riverbed in curves of the watercourse, which is based on the method of Ikeda (1975) developed for a slightly curved path in sandy riverbed. Regulated rivers have essentially slightly and smoothly curved paths; therefore, this methodology provides the appropriate basis for river restoration. Based on the research in the experimental reach of the Holeška Brook and several alluvial mountain streams the methodology was adjusted. The method also takes into account other important characteristics of bottom material - the shape and orientation of the particles, settling velocity and drag coefficients. Thus, the method is mainly meant for the natural sand-gravel material, which is heterogeneous and the particle shape of the bottom material is very different from spherical. The calculation of the river channel in the curved path provides the basis for the design of optimal habitat, but also for the design of foundations of armouring of the bankside of the channel. The input data is adapted to the conditions of design practice.

  9. Effects of alluvial knickpoint migration on floodplain ecology and geomorphology

    Science.gov (United States)

    Larsen, Annegret; May, Jan-Hendrick

    2016-04-01

    Alluvial knickpoints are well described as erosional mechanism within discontinuous ephemeral streams in the semi-arid SW USA. However, alluvial knickpoints occur globally in a wide range of settings and of climate zones, including temperate SE Australia, subtropical Africa, and tropical Australia. Much attention has been given in the scientific literature to the trigger mechanisms of alluvial knickpoints, which can be summarized as: i) threshold phenomena, ii) climate variability and iii) land-use change, or to a combination of these factors. Recently, studies have focused on the timescale of alluvial knickpoint retreat, and the processes, mechanisms and feedbacks with ecology, geomorphology and hydrology. In this study, we compile data from a global literature review with a case study on a tropical river system in Australia affected by re-occurring, fast migrating (140 myr-1) alluvial knickpoint. We highlight the importance of potential water table declines due to channel incision following knickpoint migration, which in turn leads to the destabilization of river banks, and a shift in floodplain vegetation and fire incursion. We hypothesize that the observed feedbacks might also help to understand the broader impacts of alluvial knickpoint migration in other regions, and might explain the drastic effects of knickpoint migration on land cover and land-use in semi-arid areas.

  10. Mountain-Plains Curriculum.

    Science.gov (United States)

    Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

    The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

  11. Tietkens Plain karst - Maralinga

    International Nuclear Information System (INIS)

    James, J.M.

    1988-09-01

    The Tietkens Plain karst is located to the north of Maralinga village which is on the crest of the Ooldea Range on the north and east margin of the Nullarbor Plain in western South Australia. The geology of the carbonate rocks in the Maralinga area is summarised. On Tietkens Plain from 1955 to 1963 nuclear weapons tests dispersed radioactive materials over the Maralinga area. Six nuclear devices were detonated in the air and one was exploded a few metres below the surface. The effect such explosions have on the karst and the possible rate of recovery of its surface are discussed. This report is the record of a visit to the Maralinga area from the 15th -21st November 1986 which involved an inspection of the karst surface together with collection of water, soil and rock samples. Results of the measurements made in order to assess water quality and water contamination by radioactive nuclides are presented. The implications arising from the presence of radioactive materials on the surface and the possibility of their entering and contaminating the groundwater in the area are discussed in the context of the chemistry of uranium and plutonium. The potential for transmission of contaminants through groundwater conduits and aquifers in the dolomite is discussed. Evidence is produced to show that the caves of the Nullabor Plain are not contaminated at present and are unlikely to be so in the future. 21 refs., 2 figs. 3 tabs., ills

  12. Distribution of monazite in granite and alluvial of South Bangka

    International Nuclear Information System (INIS)

    Ngadenin

    2011-01-01

    Monazite is one source of thorium (Th), which has significant economic value and potential as an alternative fuel of nuclear power plants. The aims of research is to find out the distribution monazite alternative fuel of nuclear power plants. The aims of research is to find out the distribution monazite and its potential as a resource of radioactive minerals on the Bangka Island, then the data will be used and its potential as a resource of radioactive minerals on the Bangka Island, then the data will be used as a reference in the development of radioactive minerals exploration areas in the coming year. The research location is in the Bencah and Gadung villages, South Bangka Regency. The method used is the geological mapping, sampling of rock for petrographic, mineragraphic and autoradiographic analysis and heavy mineral for grains counting analysis. The results showed that lithologic area of Bencah Village composed of clay stone and alluvial deposits, while the Gadung Village composed by granite and alluvial deposits. Granite Gadung is predicted as the ilmenite series granite and tend to be of S type, while the material of Bencah alluvial is predicted come from the Klabat granite groups. In general, distribution of monazite in the alluvial slightly more potent of monazite than in the granite so that the development of radioactive minerals exploration will be prioritized in the alluvial areas. (author)

  13. Preliminary Groundwater Simulations To Compare Different Reconstruction Methods of 3-d Alluvial Heterogeneity

    Science.gov (United States)

    Teles, V.; de Marsily, G.; Delay, F.; Perrier, E.

    Alluvial floodplains are extremely heterogeneous aquifers, whose three-dimensional structures are quite difficult to model. In general, when representing such structures, the medium heterogeneity is modeled with classical geostatistical or Boolean meth- ods. Another approach, still in its infancy, is called the genetic method because it simulates the generation of the medium by reproducing sedimentary processes. We developed a new genetic model to obtain a realistic three-dimensional image of allu- vial media. It does not simulate the hydrodynamics of sedimentation but uses semi- empirical and statistical rules to roughly reproduce fluvial deposition and erosion. The main processes, either at the stream scale or at the plain scale, are modeled by simple rules applied to "sediment" entities or to conceptual "erosion" entities. The model was applied to a several kilometer long portion of the Aube River floodplain (France) and reproduced the deposition and erosion cycles that occurred during the inferred climate periods (15 000 BP to present). A three-dimensional image of the aquifer was gener- ated, by extrapolating the two-dimensional information collected on a cross-section of the floodplain. Unlike geostatistical methods, this extrapolation does not use a statis- tical spatial analysis of the data, but a genetic analysis, which leads to a more realistic structure. Groundwater flow and transport simulations in the alluvium were carried out with a three-dimensional flow code or simulator (MODFLOW), using different rep- resentations of the alluvial reservoir of the Aube River floodplain: first an equivalent homogeneous medium, and then different heterogeneous media built either with the traditional geostatistical approach simulating the permeability distribution, or with the new genetic model presented here simulating sediment facies. In the latter case, each deposited entity of a given lithology was assigned a constant hydraulic conductivity value. Results of these

  14. Alluvial architecture of the Holocene Rhine-Meuse delta (The Netherlands) and the Lower Mississippi Valley (U.S.A.)

    NARCIS (Netherlands)

    Gouw, M.J.P.

    2007-01-01

    Alluvial architecture describes the geometry, proportion, and spatial distribution of different types of fluvial deposits in an alluvial succession. Alluvial architecture is frequently subject of study, because natural resources commonly occur in ancient fluvial sequences. The ability of models to

  15. 44 CFR 65.13 - Mapping and map revisions for areas subject to alluvial fan flooding.

    Science.gov (United States)

    2010-10-01

    ... areas subject to alluvial fan flooding. 65.13 Section 65.13 Emergency Management and Assistance FEDERAL... areas subject to alluvial fan flooding. This section describes the procedures to be followed and the... provides protection from the base flood in an area subject to alluvial fan flooding. This information must...

  16. 75 FR 62137 - Notice of Public Meeting; Proposed Alluvial Valley Floor Coal Exchange Public Interest Factors...

    Science.gov (United States)

    2010-10-07

    ... exchange Federal coal deposits for Alluvial Valley Floor (AVF) fee coal pursuant to the Federal Land Policy...; MTM-99236] Notice of Public Meeting; Proposed Alluvial Valley Floor Coal Exchange Public Interest... Alluvial Valley Floor Environmental Assessment can be viewed on the BLM's Miles City Field Office Web page...

  17. Counter diffusion of zinc and iron in alluvial soil

    International Nuclear Information System (INIS)

    Rattan, R.K.; Deb, D.L.

    1980-01-01

    Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

  18. Topographic and hydraulic controls over alluviation on a bedrock template

    Science.gov (United States)

    Milan, David; Heritage, George; Entwistle, Neil; Tooth, Stephen

    2017-04-01

    Bedrock-alluvial anastomosed channels found in dryland rivers are characterised by an over-wide channel cut into the host rock containing a network of interconnecting bedrock sub-channels separated by bedrock influenced interfluve areas. Whilst the channels remain largely free of sediment the interfluves display varying levels of alluviation ranging from bare rock, sand sheets and silt drapes through to consolidated bedrock core bars, islands and lateral deposits. Examination of the sedimentary units associated with the bedrock anastomosed reaches of the Sabie river in the Kruger National Park, South Africa reveal a repeating sequence of coarse sand / fine gravel grading through to silt representing successive flood related depositional units. Unit development in relation to the bedrock template was investigated using pre-flood aerial imagery of bedrock core bar locations and post flood LiDAR data of bedrock anastomosed sites stripped during the 2000 and 2012 extreme flood events. This revealed a propensity for bar development associated with bedrock hollows disconnected from the principal high-energy sub-channels. 2-D morpho-dynamic modelling was used to further investigate spatial patterns of deposition over the bedrock template. Although topographic lows displayed mid-range velocities during peak flow events, these are likely to be preferential routing areas, with sediments stalling in low energy areas on the falling limb of floods. It is also likely that vegetation development plays a fundamental role in the development of alluviated zones, through increasing strength of alluvial units and capturing new sediments. With these results in mind we present a conceptual model for the development of bedrock-core bars, the fundamental unit in bedrock-alluvial anastomosed channels.

  19. Quantitative groundwater modelling for a sustainable water resource exploitation in a Mediterranean alluvial aquifer

    Science.gov (United States)

    Laïssaoui, Mounir; Mesbah, Mohamed; Madani, Khodir; Kiniouar, Hocine

    2018-05-01

    To analyze the water budget under human influences in the Isser wadi alluvial aquifer in the northeast of Algeria, we built a mathematical model which can be used for better managing groundwater exploitation. A modular three-dimensional finite-difference groundwater flow model (MODFLOW) was used. The modelling system is largely based on physical laws and employs a numerical method of the finite difference to simulate water movement and fluxes in a horizontally discretized field. After calibration in steady-state, the model could reproduce the initial heads with a rather good precision. It enabled us to quantify the aquifer water balance terms and to obtain a conductivity zones distribution. The model also highlighted the relevant role of the Isser wadi which constitutes a drain of great importance for the aquifer, ensuring alone almost all outflows. The scenarios suggested in transient simulations showed that an increase in the pumping would only increase the lowering of the groundwater levels and disrupting natural balance of aquifer. However, it is clear that this situation depends primarily on the position of pumping wells in the plain as well as on the extracted volumes of water. As proven by the promising results of model, this physically based and distributed-parameter model is a valuable contribution to the ever-advancing technology of hydrological modelling and water resources assessment.

  20. Physical and microbiological properties of alluvial calcareous Çumra province soils (Central Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Ahmet Sami Erol

    2015-04-01

    Full Text Available Alluvial calcareous soils in Central Anatolia (Konya province, Çumra district has a heavy granulometric composition (average clay, low organic carbon content (less than 1%, but stable pore space structure and favorable agrophysical properties. Studies of the water regime in drip irrigation confirm favorable hydrological properties of these soils. It is assumed that the favorable structure of the pore space due to vigorous activity a large and diverse soil biota. Four phyla dominate in soil biota, among which predominate Actinobacteria. The higher (Streptomyces, and lower (three species Rhodococcus actinobacteria are predominant in large amounts as a part of this phyla. Large biodiversity at a sufficiently high bacteria richness formed the structure of the microbial community that contribute to the balanced production of specific metabolites, including gases (CO2, N2, which allows the soil to function actively, preventing compaction of the pore space and maintaining optimal density, porosity, hydrologic properties of the studied silty clay soils. m the uppermost soil horizons. Analyses of heavy mineral fraction show presence of metamorphic and igneous minerals which indicate participation of weathering products from other rock types in the nearby area. The types of heavy minerals in soils depend more on composition of parent rocks and geomorphic position than on climate type. Soils from Nova Lovcha show similar composition, but the quantity of goethite and hematite significantly increase in soil from plain. Typical high-metamorphic minerals as andalusite, kyanite and sillimanite present only in Nova Lovcha, while garnet dominates in Petrovo and opaque minerals - in Dobrostan. Red soils, formed on slopes, where erosion prevails over accumulation, contain more illite, smectite and vermiculite-smectite, and very few or no kaolinite, whereas the kaolinite is dominant in soils formed on plain. The mineralogical composition of clays in different

  1. Potentiometric Surface of the Alluvial Aquifer and Hydrologic Conditions in the Juana Diaz area, Puerto Rico, June 29 - July 1, 2005

    Science.gov (United States)

    Rodriguez, Jose M.; Santigo-Rivera, Luis; Gómez-Gómez, Fernando

    2006-01-01

    A synoptic survey of the hydrologic conditions in the Juana Diaz area, Puerto Rico, was conducted between June 29 and July 1, 2005, to define the spatial distribution of the potentiometric surface of the alluvial aquifer. The study area encompasses 21 square miles of the more extensive South Coastal Plain Alluvial Aquifer system and is bounded along the north by foothills of the Cordillera Central mountain chain, to the south by the Caribbean Sea, the east by the Rio Descalabrado and to the west by the Rio Inabon. Ground water in the Juana Diaz area is in the Quaternary-age alluvial deposits and the middle-Tertiary age Ponce Limestone and Juana Diaz Formation (Giusti, 1968). The hydraulic properties of the Ponce Limestone in the Juana Diaz area are unknown, and the Juana Diaz Formation is a unit of poor permeability due to its high clay content. Consequently, the Ponce Limestone and the Juana Diaz Formation are generally considered to be the base of the alluvial aquifer in the Juana Diaz area with ground-water flow occurring primarily within the alluvial deposits. The potentiometric-surface map of the alluvial aquifer was delineated using ground-water level measurements taken at existing wells. The water-level measurements were taken at wells that were either not pumping during the survey or were shut down for a brief period. In the latter case, a recovery period of 30 minutes was allowed for the drawdown in the wellbore to achieve a near static level position representative of the aquifer at the measurement point. Land-surface altitude from U.S. Geological Survey (USGS) 1:20,000 scale topographic maps (Playa de Ponce, Ponce, Rio Descalabrado, and Santa Isabel) were used to refer ground-water levels to mean sea level datum (National Geodetic Vertical Datum of 1929). In addition to the ground-water level measurements, the potentiometricsurface contours were delineated using hydrologic features, such as drainage ditches and saturated intermittent streams that were

  2. Correlation of alluvial deposits at the Nevada Test Site

    International Nuclear Information System (INIS)

    Grothaus, B.; Howard, N.

    1977-01-01

    Because characteristics of rock layers and problems in drilling must be studied before radioactive waste can be safely contained, an evaluation was made of methods for correlating alluvial deposits at Yucca Flat of the Nevada Test Site (NTS). Although correlation of Tertiary volcanic tuff beds at the NTS has been successfully achieved, correlation of stratigraphic zones in the overlying alluvium has posed technical difficulties. We have evaluated several methods for correlating alluvial deposits from drillholes, including electric resistivity logs (E logs), visual examination of sidewall samples and comparison of their carbonate (CO 2 ) content, downhole stereo photography for identifying debris flow deposits, caliche age-dating, and specific yield and permeability measurements of deposits. For predicting the thickness of zones having similar physical properties in the alluvium, E log measurements were found to be the most useful of these methods

  3. Metabolism of 14C-lindane in flooded alluvial soil

    International Nuclear Information System (INIS)

    Siddaramappa, R.; Sethunathan, N.

    1975-01-01

    The effect of rice straw on the persistence of uniformly ring labelled 14 C-lindane in an alluvial soil was investigated under flooded conditions. The residues in the soil were extracted with chloroform-diethyl ether and the radioactivity was measured by liquid scintillation. The radioactivity in the solvent phase decreased more rapidly in amended soil than in unamended soil. Radioautograph of thin layer chromatograms of solvent phase indicated that lindane was readily converted to a breakdown product in both amended and unamended soils. This breakdown product was also formed in both autoclaved and nonautoclaved soils. Rice straw amendment enhanced further decomposition of lindane and its breakdown product. Heat treatment retarded further decomposition of lindane and its breakdown product whereas they were rapidly decomposed in nonautoclaved soil. These studies indicated that in flooded alluvial soil tested, lindane was initially decomposed by a chemical reaction and soil microorganisms appeared to attack the products of the chemical reaction. (author)

  4. Alluvial architecture of the Holocene Rhine-Meuse delta (The Netherlands) and the Lower Mississippi Valley (U.S.A.)

    OpenAIRE

    Gouw, M.J.P.

    2007-01-01

    Alluvial architecture describes the geometry, proportion, and spatial distribution of different types of fluvial deposits in an alluvial succession. Alluvial architecture is frequently subject of study, because natural resources commonly occur in ancient fluvial sequences. The ability of models to simulate alluvial architecture realistically is largely unknown due to a lack of natural data to test the models. Generating high-resolution datasets describing alluvial architecture of natural fluv...

  5. The use of O, H and Sr isotopes and carbamazepine to identify the origin of water bodies supplying a shallow alluvial aquifer

    Science.gov (United States)

    Sassine, Lara; Le Gal La Salle, Corinne; Lancelot, Joël; Verdoux, Patrick

    2014-05-01

    Alluvial aquifers are of great socio-economic importance in France since they supply 82% of drinking water production, though they reveal to be very vulnerable to pesticides and emerging organic contaminants. The aim of this work is to identify the origin of water bodies which contribute to the recharge of an alluvial aquifer for a better understanding of its hydrochemistry and transfer of contaminants therein. The study is based on an isotopic and geochemical tracers approach, including major elements, trace elements (Br, Sr),and isotopes (δ18O, δ2H, 87Sr/86Sr), as well as organic molecules. Indeed, organic molecules such as pharmaceutical compounds, more precisely carbamazepine and caffeine, have shown their use as indicators of surface water in groundwater. The study area is a partially-confined shallow alluvial aquifer, the so-called Vistrenque aquifer, located at 15 km from the Mediterranean Sea, in the Quaternary alluviums deposited by an ancient arm of the Rhône River, in Southern France. This aquifer constitutes a shallow alluvial layer in a NE-SW graben structure. It is situated between a karst aquifer in lower Cretaceous limestones, on the NW border, and the Costières Plateau, on the SE border, having a similar geology as the Vistrenque. The alluvial plain is crossed by a surface water network with the Vistre as the main stream, and a canal used for irrigation essentially, the BRL canal, which is fed by the Rhône River. δ18O and δ2H allowed to differentiate the BRL canal water, depleted in heavy isotopes (δ2H = -71.5o vs V-SMOW), and the more enriched local rainwater (δ2H = -35.5o vs V-SMOW). In the Vistre surface water a binary mixing were evidenced with the BRL canal water and the rainwater, as end members. Then, in the Vistrenque groundwater both the BRL and the Vistre contributions could be identified, as they still show contrasting signature with local recharge. This allows to highlight the surface water contribution to a heavily exploited

  6. Woodville Karst Plain, North Florida

    OpenAIRE

    2006-01-01

    Map showing the largest mapped underwater cave systems and conduit flow paths confirmed by tracer testing relative to surface streams, sinkholes and potentiometric surface of the Florida aquifer in the Woodville Karst Plain, Florida

  7. Plain formation on Mercury: tectonic implications

    International Nuclear Information System (INIS)

    Thomas, P.

    1980-01-01

    Four major plain units, plus intermediates, are distinguished on Mercury. The chronologic relationships between these plains indicate that plains formation was a permanent process on Mercury. Their location and morphology seem to indicate a possible volcanic origin for these plains. The relationships between tectonism and volcanism seems to indicate the global contraction is not the only tectonic process on Mercury. (Auth.)

  8. Summary of Available Hydrogeologic Data for the Northeast Portion of the Alluvial Aquifer at Louisville, Kentucky

    National Research Council Canada - National Science Library

    Unthank, Michael D; Nelson, Jr., Hugh L

    2006-01-01

    The hydrogeologic characteristics of the unconsolidated glacial outwash sand and gravel deposits that compose the northeast portion of the alluvial aquifer at Louisville, Kentucky, indicate a prolific...

  9. Alluvial Diamond Resource Potential and Production Capacity Assessment of Ghana

    Science.gov (United States)

    Chirico, Peter G.; Malpeli, Katherine C.; Anum, Solomon; Phillips, Emily C.

    2010-01-01

    In May of 2000, a meeting was convened in Kimberley, South Africa, and attended by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that rough, exported diamonds were free of conflictual concerns. This meeting was supported later in 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by both diamond-producing and diamond-importing countries. Over 70 countries were included as members at the end of 2007. To prevent trade in 'conflict' diamonds while protecting legitimate trade, the KPCS requires that each country set up an internal system of controls to prevent conflict diamonds from entering any imported or exported shipments of rough diamonds. Every diamond or diamond shipment must be accompanied by a Kimberley Process (KP) certificate and be contained in tamper-proof packaging. The objective of this study was to assess the alluvial diamond resource endowment and current production capacity of the alluvial diamond-mining sector in Ghana. A modified volume and grade methodology was used to estimate the remaining diamond reserves within the Birim and Bonsa diamond fields. The production capacity of the sector was estimated using a formulaic expression of the number of workers reported in the sector, their productivity, and the average grade of deposits mined. This study estimates that there are approximately 91,600,000 carats of alluvial diamonds remaining in both the Birim and Bonsa diamond fields: 89,000,000 carats in the Birim and 2,600,000 carats in the Bonsa. Production capacity is calculated to be 765,000 carats per year, based on the formula used and available data on the number of workers and worker productivity. Annual production is highly dependent on the international diamond market and prices, the numbers of seasonal workers actively mining in the sector, and

  10. Development of A Mississippi River Alluvial Aquifer Groundwater Model

    Science.gov (United States)

    Karakullukcu, R. E.; Tsai, F. T. C.; Bhatta, D.; Paudel, K.; Kao, S. C.

    2017-12-01

    The Mississippi River Alluvial Aquifer (MRAA) underlies the Mississippi River Valley of the northeastern Louisiana, extending from the north border of Louisiana and Arkansas to south central of Louisiana. The MRAA has direct contact with the Mississippi River. However, the interaction between the Mississippi River and the alluvial aquifer is largely unknown. The MRAA is the second most used groundwater source in Louisiana's aquifers with about 390 million gallons per day, which is about 25% of all groundwater withdrawals in Louisiana. MRAA is the major water source to agriculture in the northeastern Louisiana. The groundwater withdrawals from the MRAA increases annually for irrigation. High groundwater pumping has caused significant groundwater level decline and elevated salinity in the aquifer. Therefore, dealing with agricultural irrigation is the primary purpose for managing the MRAA. The main objective of this study is to develop a groundwater model as a tool for the MRAA groundwater management. To do so, a hydrostratigraphy model of the MRAA was constructed by using nearly 8,000 drillers' logs and electric logs collected from Louisiana Department of Natural Resources. The hydrostratigraphy model clearly shows that the Mississippi River cuts into the alluvial aquifer. A grid generation technique was developed to convert the hydrostratigraphy model into a MODFLOW model with 12 layers. A GIS-based method was used to estimate groundwater withdrawals for irrigation wells based on the crop location and acreage from the USDACropScape - Cropland Data Layer. Results from the Variable Infiltration Capacity (VIC) model were used to determine potential recharge. NHDPlusV2 data was used to determine water level for major streams for the MODFLOW River Package. The groundwater model was calibrated using groundwater data between 2004 and 2015 to estimate aquifer hydraulic conductivity, specific yield, specific storage, river conductance, and surficial recharge.

  11. Exploration of an alluvial aquifer in Oman by time-domain electromagnetic sounding

    Science.gov (United States)

    Young, M. E.; de Bruijn, R. G. M.; Al-Ismaily, A. Salim

    One-third of the population of Oman depends upon groundwater extracted from the alluvium of the Batinah Plain, on the coast of the Gulf of Oman. Deep geophysical exploration techniques were used to determine the depth and nature of the alluvium and the boundaries of the aquifer. The base and structural controls of the alluvial basin at its contact with Tertiary marine sediments and Cretaceous ophiolite were mapped with seismic reflection data, recorded originally for oil exploration. The base of the alluvium dips northward from the foothills of the Northern Oman Mountains, reaching a maximum depth of 2000m at the coast. The varying facies of the alluvium are grossly characterised by different, overlapping ranges of electrical resistivity, depending largely on the clay content and degree of cementation. Resistivities near the coast are reduced by saline intrusion. These variations of resistivity were mapped with time-domain electromagnetic sounding along 400km of profile, to distinguish among the three zones of the alluvial aquifer. The wedge of saline intrusion was also delineated, up to 10km from the coast. The thickness of the saturated gravel aquifer ranges from 20-160m in an area greater than 600km2. Résumé Un tiers de la population d'Oman est alimenté par de l'eau souterraine pompée dans les alluvions de la plaine de Batinah, sur la côte du golfe d'Oman. Des techniques d'exploration géophysique profonde ont été mises en oeuvre pour déterminer la profondeur et la nature des alluvions et les limites de l'aquifère. La base et les contrôles structuraux du bassin alluvial au contact des sédiments marins tertiaires et des ophiolites crétacées ont été cartographiés à partir des données de sismique réflexion obtenues à l'origine pour la recherche pétrolière. La base des alluvions plonge vers le nord à partir du piémont du massif septentrional d'Oman, pour atteindre une profondeur maximale de 2000m sur la côte. Les divers faciès alluviaux

  12. A row-charge nuclear cratering explosion in alluvial rocks

    International Nuclear Information System (INIS)

    Kireev, V.V.; Kedrovskij, O.L.; Valentinov, Yu.A.; Myasnikov, K.V.; Nikiforov, G.A.; Prozorov, L.B.; Potapov, V.K.

    1975-01-01

    A brief description is given of the first row-charge nuclear cratering explosion in alluvial rocks carried out on the route of the Pechora-Kolva canal. The authors explain the purposes of the explosion, describe the geological conditions, indicate the emplacement parameters and yields of the charges, present data on the dynamics of development of the explosion and report on its seismic effects. The parameters of the resulting trench cut and the characteristics of the rock ejecta are also given. The possibility of using nuclear explosions for hydrotechnological projects requiring large excavations in a thick stratum of weak water-bearing rocks is considered

  13. Analysis of cutin and suberin biomarker patterns in alluvial sedi-ments

    Science.gov (United States)

    Herschbach, Jennifer; Sesterheim, Anna; König, Frauke; Fuchs, Elmar

    2015-04-01

    Cutin and suberin are the primary source of hydrolysable aliphatic lipid polyesters in soil organic matter (SOM). They are known as geochemical biomarkers to estimate the contribution of different plant species and tissues to SOM. Despite their potential as biomarkers, cutin and suberin have received less attention as flood plain sediment biomarkers. The objectives of this study were to investigate the efficiency of cutin and suberin as biomarkers in floodplains. Therefore similarities between the lipid pattern in alluvial sediments and in the actual vegetation were considered. Lipids of plant tissues (roots, twigs, leaves) from different species (reed (e.g. Phalaris arun-diacea), Salix alba, Ulmus laevis and grassland (e.g. Carex spec.)) and of the un-derlying soils and sediments were obtained and investigated at four sites in the nature reserve Knoblauchsaue (Hessen, Germany). The four sampling sites differ not only with respect to their vegetation, but also within their distance to the river Rhine. Cutin and suberin monomers of plants and soils were analysed by alkaline hydrolysis, methylation and acetylation and subsequent gas chromatography-mass spectrometry. Resulting lipid patterns were specific for the appropriate plant species and tissues. However, the traceability of single selected lipids was decreasing alongside the soil profile, with the exception of monomers in softwood floodplain soils. Selected tissue specific lipid ratios showed a higher traceability due to strong attributions of lipid ratios in soils and roots of U. laevis and Carex spec. and in leaves of U. laevis and S. alba. In contrast, there was no accordance between the suberin specific lipid ratios in soils and roots of S. alba and P. arundiacea. The most robust interpretations were afforded when a set of multiple biomarkers (i.e. a combination of free lipid ratios and ratios of hydrolysable lipids) was used to collectively reconstruct the source vegetation of different sediment layers.

  14. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    International Nuclear Information System (INIS)

    Saint-Laurent, D.; St-Laurent, J.; Hahni, M.; Chapados, C.; Ghaleb, B.

    2010-01-01

    Soils contaminated with hydrocarbons (C10,C50), polycyclic aromatic hydrocarbons (PAHs), and other contaminants (e.g., As, Cd, Cu, Pb) were recently discovered on the banks of the Saint-Francois and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios ( 204 Pb/ 206 Pb, 206 Pb/ 207 Pb, 208 Pb/ 20 '6Pb) are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88?mg kg -1 (As), 0.11 to 0.81?mg kg-1 (Cd) 12.32 to 149.13?mg kg -1 (Pb), respectively, while the 207 Pb/ 206 Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn) were detected in the hydrocarbon layer (C10,C50), most often located at the bottom of the profiles (160, 200, and 220 cm in depth). The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on flood plains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils

  15. Quality of water in alluvial aquifers in eastern Iowa

    Science.gov (United States)

    Savoca, Mark E.; Sadorf, Eric M.; Linhart, S. Michael; Barnes, Kimberlee K.

    2001-01-01

    The goal of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program is to assess the status and trends in the quality of the Nation's surface and ground water, and to better understand the natural and human factors affecting water quality. The Eastern Iowa Basins study unit encompasses an area of about 50,500 square kilometers (19,500 square miles) in eastern Iowa and southern Minnesota and is one of 59 study units in the NAWQA program. Land-use studies are an important component of the NAWQA program, and are designed to assess the concentration and distribution of water-quality constituents in recently recharged ground water associated with the most significant land use and hydrogeologic settings within a study unit. The focus of the land-use study in the Eastern Iowa Basins study unit is agricultural and urban land uses and alluvial aquifers. Agriculture is the dominant land use in the study unit. Urban areas, although not extensive, represent important potential source areas of contaminants associated with residential, commercial, and industrial activities. Alluvial aquifers are present throughout much of the study unit, and constitute a major ground-water supply that is susceptible to contamination from land-use activities.

  16. Alluvial plain dynamics and human occupation in SW Amazonia during the Holocene: A paleosol-based reconstruction

    Science.gov (United States)

    Lombardo, Umberto; Rodrigues, Leonor; Veit, Heinz

    2018-01-01

    The present study reconstructs Holocene fluvial dynamics in the southern Amazonian foreland basin through the analysis of 36 stratigraphic profiles taken along a 300 km long transect across the Llanos de Moxos (LM), in the Bolivian Amazon. Based on 50 radiocarbon ages from paleosols intercalated with fluvial sediments, the most important changes in floodplain dynamics on a millennial scale are reconstructed and the links between pre-Columbian cultural processes and environmental change in the region explored. Results show that the frequency of river avulsions and crevasses, as inferred from the number and age of the cored paleosols, is stable from 8k cal. yrs BP to 4k cal. yrs BP and increases significantly from 4k to 2k cal. yrs BP, following the strengthening of el Niño/la Niña cycle and an increase in average precipitation. Fluvial activity then decreases and reaches its minimum after 2k cal BP. A comparison between the stratigraphic record and the archaeological record shows a match between periods of landscape stability in SW Amazonia (low river activity) and periods of pre-Columbian human occupation. The first Amazonians lived in the LM until 4k yrs. BP, when an abrupt increase in the frequency of river avulsions and crevasses forced the abandonment of the region. After two thousand years of archaeological hiatus, which matches the period of highest river activity in the region, agriculturists reoccupied the Bolivian Amazon.

  17. Alluvial architecture of fluvio-deltaic successions: a review with special reference to Holocene settings

    NARCIS (Netherlands)

    Gouw, M.J.P.

    2007-01-01

    Alluvial architecture has been subject of many studies because of the occurrence of natural resources in ancient fluvial successions. This paperprovides an overview of the current state of research on alluvial architecture with special reference to Holocene fluvio-deltaic settings. Severalexamples

  18. Evaluation of hydrologic conditions and nitrate concentrations in the Rio Nigua de Salinas alluvial fan aquifer, Salinas, Puerto Rico, 2002-03

    Science.gov (United States)

    Rodriguez, Jose M.

    2006-01-01

    A ground-water quality study to define the potential sources and concentration of nitrate in the Rio Nigua de Salinas alluvial fan aquifer was conducted between January 2002 and March 2003. The study area covers about 3,600 hectares of the coastal plain within the municipality of Salinas in southern Puerto Rico, extending from the foothills to the Caribbean Sea. Agriculture is the principal land use and includes cultivation of diverse crops, turf grass, bioengineered crops for seed production, and commercial poultry farms. Ground-water withdrawal in the alluvial fan was estimated to be about 43,500 cubic meters per day, of which 49 percent was withdrawn for agriculture, 42 percent for public supply, and 9 percent for industrial use. Ground-water flow in the study area was primarily to the south and toward a cone of depression within the south-central part of the alluvial fan. The presence of that cone of depression and a smaller one located in the northeastern quadrant of the study area may contribute to the increase in nitrate concentration within a total area of about 545 hectares by 'recycling' ground water used for irrigation of cultivated lands. In an area that covers about 405 hectares near the center of the Salinas alluvial fan, nitrate concentrations increased from 0.9 to 6.7 milligrams per liter as nitrogen in 1986 to 8 to 12 milligrams per liter as nitrogen in 2002. Principal sources of nitrate in the study area are fertilizers (used in the cultivated farmlands) and poultry farm wastes. The highest nitrogen concentrations were found at poultry farms in the foothills area. In the area of disposed poultry farm wastes, nitrate concentrations in ground water ranged from 25 to 77 milligrams per liter as nitrogen. Analyses for the stable isotope ratios of nitrogen-15/nitrogen-14 in nitrate were used to distinguish the source of nitrate in the coastal plain alluvial fan aquifer. Potential nitrate loads from areas under cultivation were estimated for the

  19. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    Energy Technology Data Exchange (ETDEWEB)

    P. Goodell; J. Walton; P.J. Rodriguez

    2005-07-11

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration.

  20. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    International Nuclear Information System (INIS)

    Goodell, P.; Walton, J.; Rodriguez, P.J.

    2005-01-01

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration

  1. Sustainable Water Use System of Artesian Water in Alluvial Fan

    Science.gov (United States)

    Kishi, K.; Tsujimura, M.; Tase, N.

    2013-12-01

    The traditional water use system, developed with the intelligence of the local residents, usually takes advantage of local natural resources and is considered as a sustainable system, because of its energy saving(only forces of nature). For this reason, such kind of water use system is also recommended in some strategic policies for the purpose of a symbiosis between nature and human society. Therefore, it is important to clarify the relationship between human activities and water use systems. This study aims to clarify the mechanism of traditional water use processes in alluvial fan, and in addition, to investigate the important factors which help forming a sustainable water use system from the aspects of natural conditions and human activities. The study area, an alluvial fan region named Adogawa, is located in Shiga Prefecture, Japan and is in the west of Biwa Lake which is the largest lake in Japan. In this alluvial region where the land use is mainly occupied by settlements and paddy fields, a groundwater flowing well system is called "kabata" according to local tradition. During field survey, we took samples of groundwater, river water and lake water as well as measured the potential head of groundwater. The results showed that the upper boundary of flowing water was approximately 88m amsl, which is basically the same as the results reported by Kishi and Kanno (1966). In study area, a rapid increase of water pumping for domestic water use and melting snow during last 50 years, even if the irrigation area has decreased about 30% since 1970, and this fact may cause a decrease in recharge rate to groundwater. However, the groundwater level didn't decline based on the observed results, which is probably contributed by some water conservancy projects on Biwa Lake which maintained the water level of the lake. All the water samples are characterized by Ca-HCO3 type and similar stable isotopic value of δD and δ18O. Groundwater level in irrigation season is higher

  2. 30 CFR 785.19 - Surface coal mining and reclamation operations on areas or adjacent to areas including alluvial...

    Science.gov (United States)

    2010-07-01

    ... alluvial valley floor exists if it finds that— (i) Unconsolidated streamlaid deposits holding streams are... on areas or adjacent to areas including alluvial valley floors in the arid and semiarid areas west of....19 Surface coal mining and reclamation operations on areas or adjacent to areas including alluvial...

  3. An Assessment of Regional Water Resources and Agricultural Sustainability in the Mississippi River Alluvial Aquifer System of Mississippi and Arkansas Under Current and Future Climate

    Science.gov (United States)

    Rigby, J.; Reba, M.

    2011-12-01

    The Lower Mississippi River Alluvial Plain is a highly productive agricultural region for rice, soy beans, and cotton that depends heavily on irrigation. Development of the Mississippi River Alluvial Aquifer (MRAA), one of the more prolific agricultural aquifers in the country, has traditionally been the primary source for irrigation in the region yielding over 1,100 Mgal/day to irrigation wells. Increasingly, the realities of changing climate and rapidly declining water tables have highlighted the necessity for new water management practices. Tail-water recovery and reuse is a rapidly expanding practice due in part to the efforts and cost-sharing of the NRCS, but regional studies of the potential for such practices to alleviate groundwater mining under current and future climate are lacking. While regional studies of aquifer geology have long been available, including assessments of regional groundwater flow, much about the aquifer is still not well understood including controls on recharge rates, a crucial component of water management design. We review the trends in regional availability of surface and groundwater resources, their current status, and the effects of recent changes in management practices on groundwater decline in Mississippi and Arkansas. Global and regional climate projections are used to assess scenarios of sustainable aquifer use under current land use and management along with the potential for more widely practiced surface water capture and reuse to alleviate groundwater decline. Finally, we highlight crucial knowledge gaps and challenges associated with the development of water management practices for sustainable agricultural use in the region.

  4. The influence of the association patterns of phosphorus–substrates and xylene–substrates on the degradation of xylenes in an alluvial aquifer

    Directory of Open Access Journals (Sweden)

    SANJA MRKIC

    2005-12-01

    Full Text Available The association patterns of xylene and of total phosphorus with sediment constituents in an alluvial aquifer consisting of clays and sands which had been contaminated by a spill of technical grade xylene were investigated with the aim of assessing the dependence of in situ xylene degradation on the P-availability. The investigated alluvial sediments of the Maki{ Plain (Sava river alluvion, Quaternary age, Serbia and Montenegro are relatively poor in P. The most reliable associations were proposed by analyzing the quality of the correlations of xylene- and of P-contents with 32 sediment characteristics. The association patterns depend on the mineralogical and granulometrical composition of sediments, the structural characteristics of the organicmatter (N/C-ratio and the redox-conditions. Differing association patterns in the clays and the sand had been developed, and these characteristics influence the intrinsic xylene degradation. The main proof for the occurrence of xylene degradation is the percentul share of bacteria which oxidize xylene as a single carbon-source.

  5. Uranium favorability of late Eocene through Pliocene rocks of the South Texas Coastal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Quick, J.V.; Thomas, N.G.; Brogdon, L.D.; Jones, C.A.; Martin, T.S.

    1977-02-01

    The results of a subsurface uranium favorability study of Tertiary rocks (late Eocene through Pliocene) in the Coastal Plain of South Texas are given. In ascending order, these rock units include the Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand. The Vicksburg Group, Anahuac Formation, and Fleming Formation were not considered because they have unfavorable lithologies. The Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand contain sandstones that may be favorable uranium hosts under certain environmental and structural conditions. All except the Yegua are known to contain ore-grade uranium deposits. Yegua and Jackson sandstones are found in strand plain-barrier bar systems that are aligned parallel to depositional and structural strike. These sands grade into shelf muds on the east, and lagoonal sediments updip toward the west. The lagoonal sediments in the Jackson are interrupted by dip-aligned fluvial systems. In both units, favorable areas are found in the lagoonal sands and in sands on the updip side of the strand-plain system. Favorable areas are also found along the margins of fluvial systems in the Jackson. The Frio and Catahoula consist of extensive alluvial-plain deposits. Favorable areas for uranium deposits are found along the margins of the paleo-channels where favorable structural features and numerous optimum sands are present. The Oakville and Goliad Formations consist of extensive continental deposits of fluvial sandstones. In large areas, these fluvial sandstones are multistoried channel sandstones that form very thick sandstone sequences. Favorable areas are found along the margins of the channel sequences. In the Goliad, favorable areas are also found on the updip margin of strand-plain sandstones where there are several sandstones of optimum thickness.

  6. Uranium favorability of late Eocene through Pliocene rocks of the South Texas Coastal Plain

    International Nuclear Information System (INIS)

    Quick, J.V.; Thomas, N.G.; Brogdon, L.D.; Jones, C.A.; Martin, T.S.

    1977-02-01

    The results of a subsurface uranium favorability study of Tertiary rocks (late Eocene through Pliocene) in the Coastal Plain of South Texas are given. In ascending order, these rock units include the Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand. The Vicksburg Group, Anahuac Formation, and Fleming Formation were not considered because they have unfavorable lithologies. The Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand contain sandstones that may be favorable uranium hosts under certain environmental and structural conditions. All except the Yegua are known to contain ore-grade uranium deposits. Yegua and Jackson sandstones are found in strand plain-barrier bar systems that are aligned parallel to depositional and structural strike. These sands grade into shelf muds on the east, and lagoonal sediments updip toward the west. The lagoonal sediments in the Jackson are interrupted by dip-aligned fluvial systems. In both units, favorable areas are found in the lagoonal sands and in sands on the updip side of the strand-plain system. Favorable areas are also found along the margins of fluvial systems in the Jackson. The Frio and Catahoula consist of extensive alluvial-plain deposits. Favorable areas for uranium deposits are found along the margins of the paleo-channels where favorable structural features and numerous optimum sands are present. The Oakville and Goliad Formations consist of extensive continental deposits of fluvial sandstones. In large areas, these fluvial sandstones are multistoried channel sandstones that form very thick sandstone sequences. Favorable areas are found along the margins of the channel sequences. In the Goliad, favorable areas are also found on the updip margin of strand-plain sandstones where there are several sandstones of optimum thickness

  7. 49 CFR 229.64 - Plain bearings.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

  8. Dynamic analysis of a reactor building on alluvial soil

    International Nuclear Information System (INIS)

    Arya, A.S.; Chandrasekaran, A.R.; Paul, D.K.; Warudkar, A.S.

    1977-01-01

    The reactor building consists of reinforced concrete internal framed structure enclosed in double containment shells of prestressed and reinforced concrete all resting on a common massive raft. The external cylindrical shell is capped by a spherical dome while the internal shell carries a cellular gird slab. The building is partially buried under ground. The soil consists of alluvial going to 1000 m depth. The site lies in a moderate seismic zone. The paper presents the dynamic analysis of the building including soil-structure interaction. The mathematical model consists of four parallel, suitably interconnected struxtures, namely inner containment, outer containment, internal frame and the calandria vault. Each one of the parallel structures consists of lumped-mass beam elements. The soil below the raft and on the sides of outer containment shell is represented by elastic springs in both horizontal and vertical directions. The various assumpions required to be made in developing the mathematical model are briefly discussed in the paper. (Auth.)

  9. Occurrence of monazite in some alluvial soils of North Bihar

    International Nuclear Information System (INIS)

    Mall, J.; Mishra, B.B.

    1994-01-01

    Monazite, a thorium-bearing mineral, has been identified in the heavy mineral fractions of the fine sands from the alluvial soil profiles at Barpalia and Gyaspur of Siwan district in north Bihar. The amount of monazite varied from 14.29 to 15.40 per cent and 6.25 to 9.38 per cent of the heavy minerals in the fine sands of Barpalia and Gyaspur, respectively. Monazite could have been derived from the granite pegmatite and gneissic metamorphic rocks in association with feldspar, zircon and apatite from the Himalayan orogan. The amount of 232 Th present in monazite originally ranges from a few wt per cent ThO 2 to 10-12 per cent. Even in the east coast of India , monazite contains 9.05 per cent ThO 2 . (author).5 refs., 2 tabs., 1 fig

  10. Evaluation of the applicability of the SWAT model in an arid piedmont plain oasis.

    Science.gov (United States)

    Wu, Yong; Li, Changyou; Zhang, Chengfu; Shi, Xiaohong; Bourque, Charles P-A; Zhao, Shengnan

    2016-01-01

    Hetao Oasis is located in a typical piedmont alluvial plain bounded by the Langshan Mountain Range in the north, desert in the west, and the Yellow River in the south. Agricultural activities within the oasis significantly impact the hydrological cycle and water quality in downstream locations. The research uses the Soil and Water Assessment Tool (SWAT) for a piedmont plain by defining the watershed boundary as coinciding with the natural mountain ridge, the border between the oasis and the desert, and the Yellow River. The model simulates water discharge with coefficient of determination and a Nash-Sutcliffe model efficiency of 0.78 and 0.62 during model calibration, and 0.75 and 0.69 during model validation, suggesting that delineation of the watershed as carried out in this research is suitable for piedmont plain topography. From the results, the mountains contribute 28.4% to the water discharge at the outlet of the watershed, and water-use efficiency of irrigated water is about 40%, which is consistent with field-based measurements. Methodologies used in delineating watershed boundaries and parameterizing SWAT provide a solid foundation for water balance studies in other regions of the world with similar topography.

  11. Effects of soil water table regime on tree community species richness and structure of alluvial forest fragments in Southeast Brazil.

    Science.gov (United States)

    Silva, A C; Higuchi, P; van den Berg, E

    2010-08-01

    In order to determine the influence of soil water table fluctuation on tree species richness and structure of alluvial forest fragments, 24 plots were allocated in a point bar forest and 30 plots in five forest fragments located in a floodplain, in the municipality of São Sebastião da Bela Vista, Southeast Brazil, totalizing 54, 10 X 20 m, plots. The information recorded in each plot were the soil water table level, diameter at breast height (dbh), total height and botanical identity off all trees with dbh > 5 cm. The water table fluctuation was assessed through 1 m deep observation wells in each plot. Correlations analysis indicated that sites with shallower water table in the flooding plains had a low number of tree species and high tree density. Although the water table in the point bar remained below the wells during the study period, low tree species richness was observed. There are other events taking place within the point bar forest that assume a high ecological importance, such as the intensive water velocity during flooding and sedimentation processes.

  12. Effects of soil water table regime on tree community species richness and structure of alluvial forest fragments in Southeast Brazil

    Directory of Open Access Journals (Sweden)

    AC. Silva

    Full Text Available In order to determine the influence of soil water table fluctuation on tree species richness and structure of alluvial forest fragments, 24 plots were allocated in a point bar forest and 30 plots in five forest fragments located in a floodplain, in the municipality of São Sebastião da Bela Vista, Southeast Brazil, totalizing 54, 10 X 20 m, plots. The information recorded in each plot were the soil water table level, diameter at breast height (dbh, total height and botanical identity off all trees with dbh > 5 cm. The water table fluctuation was assessed through 1 m deep observation wells in each plot. Correlations analysis indicated that sites with shallower water table in the flooding plains had a low number of tree species and high tree density. Although the water table in the point bar remained below the wells during the study period, low tree species richness was observed. There are other events taking place within the point bar forest that assume a high ecological importance, such as the intensive water velocity during flooding and sedimentation processes.

  13. Rivers turned to rock: Late Quaternary alluvial induration influencing the behaviour and morphology of an anabranching river in the Australian monsoon tropics

    Science.gov (United States)

    Nanson, Gerald C.; Jones, Brian G.; Price, David M.; Pietsch, Timothy J.

    2005-09-01

    Late Quaternary alluvial induration has greatly influenced contemporary channel morphology on the anabranching Gilbert River in the monsoon tropics of the Gulf of Carpentaria. The Gilbert, one of a number of rivers in this region, has contributed to an extensive system of coalescing low-gradient and partly indurated riverine plains. Extensive channel sands were deposited by enhanced flow conditions during marine oxygen isotope (OI) Stage 5. Subsequent flow declined, probably associated with increased aridity, however, enhanced runoff recurred again in OI Stages 4-3 (˜65-50 ka). Aridity then capped these plains with 4-7 m of mud. A widespread network of sandy distributary channels was incised into this muddy surface from sometime after the Last Glacial Maximum (LGM) to the mid Holocene during a fluvial episode more active than the present but less so than those of OI Stages 5 and 3. This network is still partly active but with channel avulsion and abandonment now occurring largely proximal to the main Gilbert flow path. A tropical climate and reactive catchment lithology have enhanced chemical weathering and lithification of alluvium along the river resulting in the formation of small rapids, waterfalls and inset gorges, features characteristic more of bedrock than alluvial systems. Thermoluminescence (TL) and comparative optically stimulated luminescence (OSL) ages of the sediments are presented along with U/Th ages of pedogenic calcrete and Fe/Mn oxyhydroxide/ oxide accumulations. They show that calcrete precipitated during the Late Quaternary at times similar to those that favoured ferricrete formation, possibly because of an alternating wet-dry climate. Intense chemical alteration of the alluvium leading to induration appears to have prevailed for much of the Late Quaternary but, probably due to exceptional dryness, not during the LGM. The result has been restricted channel migration and a reduced capacity for the channel to adjust and accommodate sudden

  14. Changes in plain bearing technology

    CERN Document Server

    Koring, Rolf

    2012-01-01

    A unique fusion of theoretical and practical knowledge, Changes in Plain Bearing Technology, by Rolf Koring, covers a meaningful range of expertise in this field.Drawing from years of experience in design development, materials selection, and their correlation to real-life part failure, this title, co-published by SAE International and expert Verlag (Germany), concentrates on hydrodynamic bearings lined with white metals, also known as Babbits.Written under the assumption that even the most mature body of knowledge can be revisited and improved, Changes in Plain Bearing Technology is a courageous and focused approach to questioning accepted test results and looking at alternative material compounds, and their application suitability.The process, which leads to innovative answers on how the technology is transforming itself to respond to new market requirements, shows how interdisciplinary thinking can recognize new potential in long-established industrial modus operandi.Tackling the highly complex issue of co...

  15. Southern Great Plains Safety Orientation

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  16. Groundwater Recharge and Flow Regime revealed by multi-tracers approach in a headwater, North China Plain

    Science.gov (United States)

    Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie

    2014-05-01

    Groundwater recharge is a crucial hydrological process for effective water management especially in arid/ semi-arid regions. However, the insufficient number of specific research regarding groundwater recharge process has been reported previously. Intensive field surveys were conducted during rainy season, mid dry season, and end of dry season, in order to clarify comprehensive groundwater recharge and flow regime of Wangkuai watershed in a headwater, which is a main recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen 18 and deuterium were determined on all water samples. Also the stream flow rate was observed. The solute ion concentrations and stable isotopic compositions show that the most water of this region can be characterized by Ca-HCO3 type and the main water source is precipitation which is affected by altitude effect of stable isotopes. In addition, the river and reservoir of the area seem to recharge the groundwater during rainy season, whereas interaction between surface water and groundwater does not become dominant gradually after the rainy season. The inversion analysis applied in Wangkuai watershed using simple mixing model represents an existing multi-flow systems which shows a distinctive tracer signal and flow rate. In summary, the groundwater recharged at different locations in the upper stream of Wangkuai reservoir flows downward to alluvial fan with a certain amount of mixing together, also the surface water recharges certainly the groundwater in alluvial plain in the rainy season.

  17. Magnetic properties of alluvial soils polluted with heavy metals

    Science.gov (United States)

    Dlouha, S.; Petrovsky, E.; Boruvka, L.; Kapicka, A.; Grison, H.

    2012-04-01

    Magnetic properties of soils, reflecting mineralogy, concentration and grain-size distribution of Fe-oxides, proved to be useful tool in assessing the soil properties in terms of various environmental conditions. Measurement of soil magnetic properties presents a convenient method to investigate the natural environmental changes in soils as well as the anthropogenic pollution of soils with several risk elements. The effect of fluvial pollution with Cd, Cu, Pb and Zn on magnetic soil properties was studied on highly contaminated alluvial soils from the mining/smelting district (Příbram; CZ) using a combination of magnetic and geochemical methods. The basic soil characteristics, the content of heavy metals, oxalate, and dithionite extractable iron were determined in selected soil samples. Soil profiles were sampled using HUMAX soil corer and the magnetic susceptibility was measured in situ, further detailed magnetic analyses of selected distinct layers were carried out. Two types of variations of magnetic properties in soil profiles were observed corresponding to indentified soil types (Fluvisols, and Gleyic Fluvisols). Significantly higher values of topsoil magnetic susceptibility compared to underlying soil are accompanied with high concentration of heavy metals. Sequential extraction analysis proved the binding of Pb, Zn and Cd in Fe and Mn oxides. Concentration and size-dependent parameters (anhysteretic and isothermal magnetization) were measured on bulk samples in terms of assessing the origin of magnetic components. The results enabled to distinguish clearly topsoil layers enhanced with heavy metals from subsoil samples. The dominance of particles with pseudo-single domain behavior in topsoil and paramagnetic/antiferromagnetic contribution in subsoil were observed. These measurements were verified with room temperature hysteresis measurement carried out on bulk samples and magnetic extracts. Thermomagnetic analysis of magnetic susceptibility measured on

  18. Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

    Science.gov (United States)

    Gran, K. B.

    2015-12-01

    Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a

  19. Bacterial biomass and DNA diversity in an alluvial meadow soil upon long-term fertilization

    NARCIS (Netherlands)

    Naumova, N.B.; Kuikman, P.J.

    2001-01-01

    The denaturing gradient gel-electrophoresis of bacterial DNA fragments and the assessment of bacterial biomass revealed changes in the diversity of the bacterial community in a meadow alluvial soil upon long-term fertilization.

  20. Heavy metals in soils and sedimentary deposits of the Padanian Plain (Ferrara, Northern Italy). Characterisation and biomonitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bianchini, Gianluca; Natali, Claudio [Ferrara Univ. (Italy). Dept. of Earth Sciences; C.N.R, Pisa (Italy). Ist. di Geoscienze e Georisorse; Di Giuseppe, Dario; Beccaluva, Luigi [Ferrara Univ. (Italy). Dept. of Earth Sciences

    2012-08-15

    Purpose: This contribution investigates agricultural soils and sedimentary deposits in the province of Ferrara (Padanian alluvial plain, Northern Italy) in order to: examine their genesis; to define the geochemical background of the area; and to evaluate the existence of anthropogenic contamination. Moreover, environmental risk related to the presence of potentially toxic heavy metals that can be transferred into agricultural products (and consequently bio-accumulated in the food chain) was also assessed. Materials and methods: The analyses (reported in an extensive supplementary dataset) include XRD, XRF and ICP-MS assessment of bulk sediments, tests of metal extraction with aqua regia, as well as analyses of local agricultural products, i.e. biomonitoring which is important in the evaluation of element mobility. Results and discussion: Based on the results, GIS-based geochemical maps were produced and local background levels were defined. This approach demonstrated that high concentrations of Cr and Ni is a natural (geogenic) feature of the local alluvial terrains, which in turn is related to the origin and provenance of the sediments, as confirmed by the lack of top enrichment in all of the investigated sites. Tests of metal extraction and analyses of agricultural products provide guidelines for agricultural activities, suggesting that extensive use of sewage sludge, industrial slurry and manure (that are often rich in metals) should be minimised. Conclusions: The dataset reported in this paper shows that the agricultural terrains of the studied alluvial plain are not characterised by anthropogenic heavy metal pollution. In spite of the elevated natural background of Cr and Ni, most of the local agricultural products do not show significant evidence of bio-magnification. Exceptions are represented by forage grass (alfalfa) and corn (maize) that tend to uptake As and Ni, respectively. This demonstrates that in agricultural areas, a geochemical risk assessment

  1. Hydrochemical Processes in the Alluvial Aquifer of the Gwydir River (Northern New South Wales, Australia)

    OpenAIRE

    Menció, Anna; Mas-Pla, Josep; Korbel, Kathryn; Hose, Grant C.

    2013-01-01

    The hydrochemistry of the Narrabri Formation, the shallow aquifer system of the alluvial fan of the Gwydir River (NSW, Australia), is analyzed to better understand the hydrogeological processes involved in aquifer recharge, and to set up future management options that preserve the quantity and quality of water resources. Results show that groundwater hydrochemistry in this alluvial aquifer is mainly controlled by silicate weathering and cation exchange. However, salt remobilization in specifi...

  2. Clay Mineralogy of AN Alluvial Aquifer in a Mountainous, Semiarid Terrain, AN Example from Rifle, Colorado

    Science.gov (United States)

    Elliott, W. C.; Lim, D.; Zaunbrecher, L. K.; Pickering, R. A.; Williams, K. H.; Navarre-Sitchler, A.; Long, P. E.; Noel, V.; Bargar, J.; Qafoku, N. P.

    2015-12-01

    Alluvial sediments deposited along the Colorado River corridor in the semi-arid regions of central to western Colorado can be important hosts for legacy contamination including U, V, As and Se. These alluvial sediments host aquifers which are thought to provide important "hot spots" and "hot moments" for microbiological activity controlling organic carbon processing and fluxes in the subsurface. Relatively little is known about the clay mineralogy of these alluvial aquifers and the parent alluvial sediments in spite of the fact that they commonly include lenses of silt-clay materials. These lenses are typically more reduced than coarser grained materials, but zones of reduced and more oxidized materials are present in these alluvial aquifer sediments. The clay mineralogy of the non-reduced parent alluvial sediments of the alluvial aquifer located in Rifle, CO (USA) is composed of chlorite, smectite, illite, kaolinite and quartz. The clay mineralogy of non-reduced fine-grained materials at Rifle are composed of the same suite of minerals found in the sediments plus a vermiculite-smectite intergrade that occurs near the bottom of the aquifer near the top of the Wasatch Formation. The clay mineral assemblages of the system reflect the mineralogically immature character of the source sediments. These assemblages are consistent with sediments and soils that formed in a moderately low rainfall climate and suggestive of minimal transport of the alluvial sediments from their source areas. Chlorite, smectite, smectite-vermiculite intergrade, and illite are the likely phases involved in the sorption of organic carbon and related microbial redox transformations of metals in these sediments. Both the occurrence and abundance of chlorite, smectite-vermiculite, illite and smectite can therefore exert an important control on the contaminant fluxes and are important determinants of biogeofacies in mountainous, semiarid terrains.

  3. Radio monitoring of the Sozh-river flood plain

    International Nuclear Information System (INIS)

    Kuznetsova, V.A.; Generalova, V.A.; Kol'nenkov, V.P.; Glaz, A.S.

    2001-01-01

    only in 2,3 that is connected with the fresh radioactive material introduction by the river is marked. According to monitoring supervision of 1990 and 1997, the specific radioactivity of a terrestrial surface in the village Serebrovichy of Chechersk district made 120-130 and 135-140 mc R/h correspondingly. The reduction of Cs-137 concentration is basically connected with the burial radioactive dead channel silts of the first years of sedimentation after the Chernobyl disaster under younger and less radioactive river deposits, and also with partial silt carrying out. The water-producing territories near the villages still remain highly contaminated. Thus, as supervision shows, the radioactivity in the abnormal zones located in the Sozh-river flood plain, remains high, the conditions of secondary redistribution and accumulation of technogenic isotopes in alluvial streams of dispersion are kept. Monitoring supervision is proceeding

  4. Diagenesis of Permian alluvial fan deposits of Northern Switzerland

    International Nuclear Information System (INIS)

    Bluem, W.

    1987-01-01

    Fine-grained sandstones of Permian alluvial fan deposits from three Nagra boreholes (Weiach, Riniken, Kaisten) and an exploration well, drilled at Wintersingen are clast supported, moderately sorted arkosic greywackes containing typically 2-20 % clayey matrix. Petrographic studies indicate that the origin of this clayey matrix is postdepositional. Mechanical infiltration of fines and diagenetic reddening of detrital and authigenic iron oxides are the earliest recorded events. Additionally, nodular calcites of calcrete origin and fibrous illitic clays are also ascribed to the eogenetic environment. The present strong compaction fabric results from general lack of eogenetic framework supporting cements. During mesogenesis, secondary porosity was generated through partial removal of early calcite. At the same time, a first generation of syntaxial quartz cementation and a subsequent fibrous illite authigenesis took place. Leaching of detrital K-feldspars post-dating compaction is recorded throughout the studied boreholes. The following burial diagenetic events differ between the various boreholes: in Weiach and Wintersingen kaolinite, illite, prismatic quartz and ankerite/siderite are recorded; in Riniken K-feldspar, illite, prismatic quartz and dolomite developed; whilst in Kaisten K-feldspar and microcrystalline quartz-cement dominate. These differences reflect the chemistry, pH and ionic strength of the pore fluids. Filling of veins by dolomite/ankerite, iron-rich and subsequent iron-poor calcite is the latest recorded event. (author) 21 refs., 10 figs., 1 tab

  5. Colonizing Dynamic Alluvial and Coastal Landscapes in the Holocene

    Science.gov (United States)

    Kidder, T.; Liu, X.; Ervin, K.

    2017-12-01

    Throughout the Holocene humans have had to adapt to dynamic, rapidly changing alluvial and coastal landscapes. Understanding when people inhabit a given environment is an important starting point for exploring human adaptations, but increasingly we need to consider how, and especially why certain environments are used—or not used— so we can understand the consequences of these human actions. Using four case studies—one from the Yellow River Valley, China, one from coastal Jiangsu, China, one from the Mississippi River Valley (Mississippi, USA) and one from the Mississippi River delta (Louisiana , USA)—we develop a model of how humans at various stages of cultural development colonize new environments. Using archaeological data and ecological modeling we investigate the relationship between the timing of landscape colonization and the ecological richness and predictability of any given environment. As new landscapes emerge and mature humans adopt different strategies for exploiting these novel environments that begins with episodic use and increasingly shifts to stable, long-term habitation. The early phase of landscape colonization appears to be the most significant period because it shapes human environmental practices and sets each culture on a trajectory of socio-cultural development. Thus, human-environment interaction is a critical part of the emergence of cultural patterns that shapes the past, present, and even the future.

  6. Diazotrophy in alluvial meadows of subarctic river systems.

    Directory of Open Access Journals (Sweden)

    Thomas H DeLuca

    Full Text Available There is currently limited understanding of the contribution of biological N2 fixation (diazotrophy to the N budget of large river systems. This natural source of N in boreal river systems may partially explain the sustained productivity of river floodplains in Northern Europe where winter fodder was harvested for centuries without fertilizer amendments. In much of the world, anthropogenic pollution and river regulation have nearly eliminated opportunities to study natural processes that shaped early nutrient dynamics of large river systems; however, pristine conditions in northern Fennoscandia allow for the retrospective evaluation of key biochemical processes of historical significance. We investigated biological N2 fixation (diazotrophy as a potential source of nitrogen fertility at 71 independent floodplain sites along 10 rivers and conducted seasonal and intensive analyses at a subset of these sites. Biological N2 fixation occurred in all floodplains, averaged 24.5 kg N ha(-1 yr(-1 and was down regulated from over 60 kg N ha(-1 yr(-1 to 0 kg N ha(-1 yr(-1 by river N pollution. A diversity of N2-fixing cyanobacteria was found to colonize surface detritus in the floodplains. The data provide evidence for N2 fixation to be a fundamental source of new N that may have sustained fertility at alluvial sites along subarctic rivers. Such data may have implications for the interpretation of ancient agricultural development and the design of contemporary low-input agroecosystems.

  7. Woody riparian vegetation response to different alluvial water table regimes

    Science.gov (United States)

    Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

    2000-01-01

    Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

  8. The Graded Alluvial River: Variable Flow and the Dominant Discharge

    Science.gov (United States)

    Blom, A.; Arkesteijn, L.; Viparelli, E.

    2016-12-01

    We derive analytical formulations for the graded or equilibrium longitudinal profile of a mixed-sediment alluvial river under variable flow. The formulations are applicable to reaches upstream from the backwater zone. The model is based on the conservation equations for the mass of two distinct sediment modes, sand and gravel, at the bed surface to account for the effects of grain size selective transport and abrasion of gravel particles. The effects of a variable flow rate are included by (a) treating the flow as a continuously changing yet steady water discharge (i.e. here termed an alternating steady discharge) and (b) assuming the time scale of changes in channel slope and bed surface texture to be much larger than the one of changes in flow rate. The equations are simplified realizing that at equilibrium the river profile finds itself in a dynamic steady state with oscillations around constant mean values of channel slope and bed surface texture. A generalized sediment transport relation representing the stochastic nature of sediment transport allows for explicit or analytical solutions to the streamwise decrease of both the channel slope and the bed surface mean grain size under variable flow for reaches unaffected by backwater effects. This modelling approach also provides a definition of a channel-forming or dominant water discharge, i.e., that steady water discharge that is equivalent in its effect on the equilibrium channel slope to the full hydrograph.

  9. Hydrocarbon Status of Alluvial Soils in the Istra Morphostructural Node (Moscow Oblast)

    Science.gov (United States)

    Pikovskiy, Yu. I.; Gennadiev, A. N.; Kovach, R. G.; Khlynina, N. I.; Khlynina, A. V.

    2017-12-01

    The effect of the current block structure of the earth's crust and its most active sites (morphostructural nodes) on the natural hydrocarbon status of alluvial soils has been considered. Studies have been performed in the Istra district of Moscow oblast within the Istra morphostructural node. The node represents an area of increased geodynamic activity of the earth's crust located at the convergence or intersection of block boundaries: mobile linear zones following large river valleys with alluvial soils. Soil cover mainly consists of alluvial humic-gley soils (Eutric Gleyic Fluvisols) of different depths and alluvial mucky-gley soils (Eutric Gleyic Histic Fluvisols). Some soils manifest stratification. Two factors forming the hydrocarbon status of soils are considered: soil processes and the effect of geodynamic activity, which is manifested within the morphostructural node. The contents of bitumoids and retained methane and butanes in alluvial soils appreciably increase at the entry of river valley into the node. The occurrence frequency of 5-6-ring polycyclic aromatic hydrocarbons (perylene and benzo[ghi]perylene) in mineral horizons increases. It has been concluded that alluvial soils within the Istra morphostructural node are characterized by the biogeochemical type of hydrocarbon status with signs of emanation type at sites with the highest geodynamic activity.

  10. The “Alluvial Mesovoid Shallow Substratum”, a New Subterranean Habitat

    Science.gov (United States)

    Ortuño, Vicente M.; Gilgado, José D.; Jiménez-Valverde, Alberto; Sendra, Alberto; Pérez-Suárez, Gonzalo; Herrero-Borgoñón, Juan J.

    2013-01-01

    In this paper we describe a new type of subterranean habitat associated with dry watercourses in the Eastern Iberian Peninsula, the “Alluvial Mesovoid Shallow Substratum” (alluvial MSS). Historical observations and data from field sampling specially designed to study MSS fauna in the streambeds of temporary watercourses support the description of this new habitat. To conduct the sampling, 16 subterranean sampling devices were placed in a region of Eastern Spain. The traps were operated for 12 months and temperature and relative humidity data were recorded to characterise the habitat. A large number of species was captured, many of which belonged to the arthropod group, with marked hygrophilous, geophilic, lucifugous and mesothermal habits. In addition, there was also a substantial number of species showing markedly ripicolous traits. The results confirm that the network of spaces which forms in alluvial deposits of temporary watercourses merits the category of habitat, and here we propose the name of “alluvial MSS”. The “alluvial MSS” may be covered or not by a layer of soil, is extremely damp, provides a buffer against above ground temperatures and is aphotic. In addition, compared to other types of MSS, it is a very unstable habitat. It is possible that the “alluvial MSS” may be found in other areas of the world with strongly seasonal climatic regimes, and could play an important role as a biogeographic corridor and as a refuge from climatic changes. PMID:24124544

  11. Groundwater Recharge Processes Revealed By Multi-Tracers Approach in a Headwater, North China Plain

    Science.gov (United States)

    Sakakibara, K.; Tsujimura, M.; Song, X.; Zhang, J.

    2014-12-01

    Groundwater recharge variation in space and time is crucial for effective water management especially in arid/ semi-arid regions. In order to reveal comprehensive groundwater recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were conducted at 4 times in different seasons in Wangkuai watershed, Taihang Mountains, which is a main groundwater recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate was observed in stable state condition. The stable isotopic compositions, silica and bicarbonate concentrations in the groundwater show close values as those in the surface water, suggesting main groundwater recharge occurs from surface water at mountain-plain transitional zone throughout a year. Also, the deuterium and oxgen-18 in the Wangkuai reservoir and the groundwater in the vicinity of the reservoir show higher values, suggesting the reservoir water, affected by evaporation effect, seems to have an important role for the groundwater recharge in alluvial plain. For specifying the groundwater recharge area and quantifying groundwater recharge rate from the reservoir, an inversion analysis and a simple mixing model were applied in Wangkuai watershed using stable isotopes of oxygen-18 and deuterium. The model results show that groundwater recharge occurs dominantly at the altitude from 357 m to 738 m corresponding to mountain-plain transitional zone, and groundwater recharge rate by Wangkuai reservoir is estimated to be 2.4 % of total groundwater recharge in Wangkuai watershed.

  12. Combining Landform Thematic Layer and Object-Oriented Image Analysis to Map the Surface Features of Mountainous Flood Plain Areas

    Science.gov (United States)

    Chuang, H.-K.; Lin, M.-L.; Huang, W.-C.

    2012-04-01

    The Typhoon Morakot on August 2009 brought more than 2,000 mm of cumulative rainfall in southern Taiwan, the extreme rainfall event caused serious damage to the Kaoping River basin. The losses were mostly blamed on the landslides along sides of the river, and shifting of the watercourse even led to the failure of roads and bridges, as well as flooding and levees damage happened around the villages on flood bank and terraces. Alluvial fans resulted from debris flow of stream feeders blocked the main watercourse and debris dam was even formed and collapsed. These disasters have highlighted the importance of identification and map the watercourse alteration, surface features of flood plain area and artificial structures soon after the catastrophic typhoon event for natural hazard mitigation. Interpretation of remote sensing images is an efficient approach to acquire spatial information for vast areas, therefore making it suitable for the differentiation of terrain and objects near the vast flood plain areas in a short term. The object-oriented image analysis program (Definiens Developer 7.0) and multi-band high resolution satellite images (QuickBird, DigitalGlobe) was utilized to interpret the flood plain features from Liouguei to Baolai of the the Kaoping River basin after Typhoon Morakot. Object-oriented image interpretation is the process of using homogenized image blocks as elements instead of pixels for different shapes, textures and the mutual relationships of adjacent elements, as well as categorized conditions and rules for semi-artificial interpretation of surface features. Digital terrain models (DTM) are also employed along with the above process to produce layers with specific "landform thematic layers". These layers are especially helpful in differentiating some confusing categories in the spectrum analysis with improved accuracy, such as landslides and riverbeds, as well as terraces, riverbanks, which are of significant engineering importance in disaster

  13. Dynamic analysis of a reactor building on alluvial soil

    International Nuclear Information System (INIS)

    Arya, A.S.; Chandrasekaran, A.R.; Paul, D.K.

    1977-01-01

    The reactor building consists of reinforced concrete internal framed structure enclosed in double containment shells of prestressed and reinforced concrete all resting on a common massive raft. The external cylindrical shell is capped by a spherical dome while the internal shell carries a cellular grid slab. The building is partially buried under ground. The soil consists of alluvial going to 1000 m depth. The site lies in a moderate seismic zone. The paper presents the dynamic analysis of the building including soil-structure interaction. The mathematical model consists of four parallel, suitably interconnected structures, namely inner containment, outer containment, internal frame and the calandria vault. Each one of the parallel structures consists of lumped-mass beam elements. The soil below the raft and on the sides of outer containment shell is represented by elastic springs in both horizontal and vertical directions. The various assumptions required to be made in developing the mathematical model are briefly discussed in the paper. Transfer matrix technique has been used to determine the frequencies and mode shapes. The deformations due to bending, shear and effect of the rotary inertia have been included. Various alternatives of laterally interconnecting the internals and the shells have been examined and the best alternative from earthquake considerations has been obtained. In the study, the effect of internal structure flexibility and Calandria vault flexibility on the whole building have been studied. The resulting base raft motion and the structural timewise response of all floors have been determined for the design basis (safe shutdown) earthquake by mode superposition

  14. ESR as a method for the characterization of alluvial sediments

    International Nuclear Information System (INIS)

    Tissoux, H.; Voinchet, P.; Lacquement, F.; Despriée, J.

    2015-01-01

    The possibility of using the parameters involved in the ESR dating of optically bleached quartz grains in a purpose of source determination was checked. In that aim, samples previously taken in different sedimentary formations of the Middle Loire Basin (Central France) and dated by ESR have been observed. First discrimination was made using the thorium and potassium content in the sediments obtained by gamma spectrometry. The plot of these 119 data on the Th/K Schlumberger diagram clearly demonstrated that it was possible to discriminate the clays associations included in the sediment from which the dated quartz are extracted. Clay's nature could then be indicative of the geological nature of the substratum of rivers from their sources. Second discrimination was made using the ESR intensities calculated from Al, Ti–H and Ti–Li paramagnetic centres on 18 samples. It appears that the combination of the non-bleachable aluminum trap (DAT) saturation intensity and the Ti–H/Ti–Li ratio intensities make possible the discrimination of the two main sources of the sediment: Massif Central and Paris Basin. More deeply, The Ti/OBAT (Optically bleachable aluminum traps) intensities made possible the discrimination of quartz grains of different geological sources or with different geothermal history within the Massif Central group. - Highlights: • We used ESR and gamma spectrometry for source determination of alluvial quartz grains. • Th/K ratio distinguishes sediments from rivers flowing in various geological contexts. • Al, Ti–H and Ti–Li ESR centers discriminate quartz of different geological sources.

  15. Geotechnical Parameters of Alluvial Soils from in-situ Tests

    Science.gov (United States)

    Młynarek, Zbigniew; Stefaniak, Katarzyna; Wierzbicki, Jedrzej

    2012-10-01

    The article concentrates on the identification of geotechnical parameters of alluvial soil represented by silts found near Poznan and Elblag. Strength and deformation parameters of the subsoil tested were identified by the CPTU (static penetration) and SDMT (dilatometric) methods, as well as by the vane test (VT). Geotechnical parameters of the subsoil were analysed with a view to using the soil as an earth construction material and as a foundation for buildings constructed on the grounds tested. The article includes an analysis of the overconsolidation process of the soil tested and a formula for the identification of the overconsolidation ratio OCR. Equation 9 reflects the relation between the undrained shear strength and plasticity of the silts analyzed and the OCR value. The analysis resulted in the determination of the Nkt coefficient, which might be used to identify the undrained shear strength of both sediments tested. On the basis of a detailed analysis of changes in terms of the constrained oedometric modulus M0, the relations between the said modulus, the liquidity index and the OCR value were identified. Mayne's formula (1995) was used to determine the M0 modulus from the CPTU test. The usefullness of the sediments found near Poznan as an earth construction material was analysed after their structure had been destroyed and compacted with a Proctor apparatus. In cases of samples characterised by different water content and soil particle density, the analysis of changes in terms of cohesion and the internal friction angle proved that these parameters are influenced by the soil phase composition (Fig. 18 and 19). On the basis of the tests, it was concluded that the most desirable shear strength parameters are achieved when the silt is compacted below the optimum water content.

  16. Evaluation of reforestation in the Lower Mississippi River Alluvial Valley

    Science.gov (United States)

    King, S.L.; Keeland, B.D.

    1999-01-01

    Only about 2.8 million ha of an estimated original 10 million ha of bottomland hardwood forests still exist in the Lower Mississippi River Alluvial Valley (LMAV) of the United States. The U.S. Fish and Wildlife Service, the U.S. Forest Service, and state agencies initiated reforestation efforts in the late 1980s to improve wildlife habitat. We surveyed restorationists responsible for reforestation in the LMAV to determine the magnitude of past and future efforts and to identify major limiting factors. Over the past 10 years, 77,698 ha have been reforested by the agencies represented in our survey and an additional 89,009 ha are targeted in the next 5 years. Oaks are the most commonly planted species and bare-root seedlings are the most commonly used planting stock. Problems with seedling availability may increase the diversity of plantings in the future. Reforestation in the LMAV is based upon principles of landscape ecology; however, local problems such as herbivory, drought, and flooding often limit success. Broad-scale hydrologic restoration is needed to fully restore the structural and functional attributes of these systems, but because of drastic and widespread hydrologic alterations and socioeconomic constraints, this goal is generally not realistic. Local hydrologic restoration and creation of specific habitat features needed by some wildlife and fish species warrant attention. More extensive analyses of plantings are needed to evaluate functional success. The Wetland Reserve Program is a positive development, but policies that provide additional financial incentives to landowners for reforestation efforts should be seriously considered.

  17. Localized sulfate-reducing zones in a coastal plain aquifer

    Science.gov (United States)

    Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.

    1999-01-01

    High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.

  18. Measuring Paleolandscape Relief in Alluvial River Systems from the Stratigraphic Record

    Science.gov (United States)

    Hajek, E. A.; Trampush, S. M.; Chamberlin, E.; Greenberg, E.

    2017-12-01

    Aggradational alluvial river systems sometimes generate relief in the vicinity of their channel belts (i.e. alluvial ridges) and it has been proposed that this process may define important thresholds in river avulsion. The compensation scale can be used to estimate the maximum relief across a landscape and can be connected to the maximum scale of autogenic organization in experimental and numerical systems. Here we use the compensation scale - measured from outcrops of Upper Cretaceous and Paleogene fluvial deposits - to estimate the maximum relief that characterized ancient fluvial landscapes. In some cases, the compensation scale significantly exceeds the maximum channel depth observed in a deposit, suggesting that aggradational alluvial systems organize to sustain more relief than might be expected by looking only in the immediate vicinity of the active channel belt. Instead, these results indicate that in some systems, positive topographic relief generated by multiple alluvial ridge complexes and/or large-scale fan features may be associated with landscape-scale autogenic organization of channel networks that spans multiple cycles of channel avulsion. We compare channel and floodplain sedimentation patterns among the studied ancient fluvial systems in an effort to determine whether avulsion style, channel migration, or floodplain conditions influenced the maximum autogenic relief of ancient landscapes. Our results emphasize that alluvial channel networks may be organized at much larger spatial and temporal scales than previously realized and provide an avenue for understanding which types of river systems are likely to exhibit the largest range of autogenic dynamics.

  19. Alluvial systems as archives for environmental change at a Hominid site with Oldowan archaeological occurrences: the Homa Peninsula, southwestern Kenya

    Science.gov (United States)

    Vincent, Thomas; Whitfield, Elizabeth; Kirby, Jason; Hunt, Christopher; Bishop, Laura; Plummer, Thomas; Ditchfield, Peter

    2016-04-01

    The Homa Peninsula, southwestern Kenya, preserves fossiliferous sedimentary sequences dating to the Plio-Pleistocene. Evidence of hominids inhabiting an open grassland setting and utilising Oldowan tools has been reported here, as well as some of the oldest known traces of hominin activity. Reconstructions of the palaeoenvironment have suggested that alluvial and lake marginal environments on a grassy plain, between wooded slopes and a permanent water body might be plausible. However, these interpretations are based only on field sedimentological analyses and stable isotope analysis at a single site on the peninsula (Kanjera South). It is the aim of this study to utilise a multiproxy approach to develop our understanding of the palaeoenvironmental characteristics here. Sediments will also be characterized at a new site (Nyayanga) through field analyses, as well as through analyses of particle size, siliceous microfossils (diatoms, phytoliths and sponge spicules), pollen and stable isotopes. By utilizing this approach, new insights into the palaeoecology, palaeohydromorphology and palaeoclimate of the locale may be revealed, expanding the limited data available to palaeoanthropological studies of Oldowan occurrences in east Africa. Efforts to refine palaeoenvironmental reconstructions of Kanjera South through particle size analysis have shown that sediments in the lower beds of the sequence are characterised by poor sorting, a bimodal distribution and sand/silty-sand grade material. This suggests rapid deposition and/or a variable hydrological regime and may represent the role of relatively unconfined ephemeral channels in the transportation and deposition of sediments. Fluvial reworking of aeolian sediments, most likely during unconfined flood events may also have occurred.

  20. Rome in its setting. Post-glacial aggradation history of the Tiber River alluvial deposits and tectonic origin of the Tiber Island

    Science.gov (United States)

    Motta, Laura; Brock, Andrea L.; Macrì, Patrizia; Florindo, Fabio; Sadori, Laura; Terrenato, Nicola

    2018-01-01

    The Tiber valley is a prominent feature in the landscape of ancient Rome and an important element for understanding its urban development. However, little is known about the city’s original setting. Our research provides new data on the Holocene sedimentary history and human-environment interactions in the Forum Boarium, the location of the earliest harbor of the city. Since the Last Glacial Maximum, when the fluvial valley was incised to a depth of tens of meters below the present sea level, 14C and ceramic ages coupled with paleomagnetic analysis show the occurrence of three distinct aggradational phases until the establishment of a relatively stable alluvial plain at 6–8 m a.s.l. during the late 3rd century BCE. Moreover, we report evidence of a sudden and anomalous increase in sedimentation rate around 2600 yr BP, leading to the deposition of a 4-6m thick package of alluvial deposits in approximately one century. We discuss this datum in the light of possible tectonic activity along a morpho-structural lineament, revealed by the digital elevation model of this area, crossing the Forum Boarium and aligned with the Tiber Island. We formulate the hypothesis that fault displacement along this structural lineament may be responsible for the sudden collapse of the investigated area, which provided new space for the observed unusually large accumulation of sediments. We also posit that, as a consequence of the diversion of the Tiber course and the loss in capacity of transport by the river, this faulting activity triggered the origin of the Tiber Island. PMID:29590208

  1. Alluvial diamond resource potential and production capacity assessment of Mali

    Science.gov (United States)

    Chirico, Peter G.; Barthelemy, Francis; Kone, Fatiaga

    2010-01-01

    In May of 2000, a meeting was convened in Kimberley, South Africa, and attended by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that rough, exported diamonds were free of conflictual concerns. This meeting was supported later in 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberley Process Certification Scheme (KPCS) was ratified and signed by diamond-producing and diamond-importing countries. Over 70 countries were included as members of the KPCS at the end of 2007. To prevent trade in "conflict diamonds" while protecting legitimate trade, the KPCS requires that each country set up an internal system of controls to prevent conflict diamonds from entering any imported or exported shipments of rough diamonds. Every diamond or diamond shipment must be accompanied by a Kimberley Process (KP) certificate and be contained in tamper-proof packaging. The objective of this study was (1) to assess the naturally occurring endowment of diamonds in Mali (potential resources) based on geological evidence, previous studies, and recent field data and (2) to assess the diamond-production capacity and measure the intensity of mining activity. Several possible methods can be used to estimate the potential diamond resource. However, because there is generally a lack of sufficient and consistent data recording all diamond mining in Mali and because time to conduct fieldwork and accessibility to the diamond mining areas are limited, four different methodologies were used: the cylindrical calculation of the primary kimberlitic deposits, the surface area methodology, the volume and grade approach, and the content per kilometer approach. Approximately 700,000 carats are estimated to be in the alluvial deposits of the Kenieba region, with 540,000 carats calculated to lie within the concentration grade deposits. Additionally, 580,000 carats are estimated to have

  2. Conditions for tidal bore formation in convergent alluvial estuaries

    Science.gov (United States)

    Bonneton, Philippe; Filippini, Andrea Gilberto; Arpaia, Luca; Bonneton, Natalie; Ricchiuto, Mario

    2016-04-01

    Over the last decade there has been an increasing interest in tidal bore dynamics. However most studies have been focused on small-scale bore processes. The present paper describes the first quantitative study, at the estuary scale, of the conditions for tidal bore formation in convergent alluvial estuaries. When freshwater discharge and large-scale spatial variations of the estuary water depth can be neglected, tide propagation in such estuaries is controlled by three main dimensionless parameters: the nonlinearity parameter ε0 , the convergence ratio δ0 and the friction parameter ϕ0. In this paper we explore this dimensionless parameter space, in terms of tidal bore occurrence, from a database of 21 estuaries (8 tidal-bore estuaries and 13 non tidal-bore estuaries). The field data point out that tidal bores occur for convergence ratios close to the critical convergence δc. A new proposed definition of the friction parameter highlights a clear separation on the parameter plane (ϕ0,ε0) between tidal-bore estuaries and non tidal-bore estuaries. More specifically, we have established that tidal bores occur in convergent estuaries when the nonlinearity parameter is greater than a critical value, εc , which is an increasing function of the friction parameter ϕ0. This result has been confirmed by numerical simulations of the two-dimensional Saint Venant equations. The real-estuary observations and the numerical simulations also show that, contrary to what is generally assumed, tide amplification is not a necessary condition for tidal bore formation. The effect of freshwater discharge on tidal bore occurrence has been analyzed from the database acquired during three long-term campaigns carried out on the Gironde/Garonne estuary. We have shown that in the upper estuary the tidal bore intensity is mainly governed by the local dimensionless tide amplitude ε. The bore intensity is an increasing function of ε and this relationship does not depend on freshwater

  3. Braidplain, floodplain and playa lake, alluvial-fan, aeolian and palaeosol facies composing a diversified lithogenetical sequence in the permian and triassic of South Devon (England)

    Science.gov (United States)

    Mader, Detlef

    The Permian and Triassic of South Devon (England) are a continental red bed sequence of very diversified lithogenetical composition. Within the thick series, the distribution of the main depositional environments being fluvial braidplain, fluvial floodplain and playa lake, alluvial fan, aeolian dune and calcrete palaeosol changes repeatedly in both horizontal and vertical direction. Significant sedimentary milieus such as aeolian dunes and calcrete palaeosols occur repeatedly within the succession, but are also lacking in several parts of the sequence. Fluvial braidplain deposits comprise conglomerates, sandstones, intraformational reworking horizons and mudstones and originate in channels and overbank plains of a braided river system. Conglomerates and sandstones are formed by migration of bars and spreading out of sheets during infilling of streams and aggradation of flats. Gravel is often enriched as lag pockets or veneers within steeper scour holes and kolk pots or on the plane floor of the watercourse. Finer-grained sandstones and mudstones are laid down by suspension settling in stagnant water bodies such as small lakes in the overbank area and residual pools in interbar depressions during low-stage or waning-flow in active channels or in abandoned streams. Spectacular bioturbation features in some sandstones with both horizontal tubes and vertical burrows testify to the colonization of the sediments at the bottom of the rivers with declining discharge and transport capacity. Intraformational reworking horizons with ghost-like remnants of degraded sandstones, mudstones and pedogenic carbonates document partially severe condensation of the sequence by removal of some facies elements from the depositional record. The occasionally occurring gravel-bearing mudstones or silty-clayey sandstones represent products of high-energy water surges overspilling the channel banks and transporting sandy and gravelly bed-load in limited amounts beyond the levee wall. The

  4. Climate variability and Great Plains agriculture

    International Nuclear Information System (INIS)

    Rosenberg, N.J.; Katz, L.A.

    1991-01-01

    The ways in which inhabitants of the Great Plains, including Indians, early settlers, and 20th century farmers, have adapted to climate changes on the Great Plains are explored. The climate of the Great Plains, because of its variability and extremes, can be very stressful to plants, animals and people. It is suggested that agriculture and society on the Great Plains have, during the last century, become less vulnerable to the stresses imposed by climate. Opinions as to the sustainability of agriculture on the Great Plains vary substantially. Lockeretz (1981) suggests that large scale, high cost technologies have stressed farmers by creating surpluses and by requiring large investments. Opie (1989) sees irrigation as a climate substitute, however he stresses that the Ogallala aquifer must inevitably become depleted. Deborah and Frank Popper (1987) believe that farming on the Plains is unsustainable, and destruction of shelterbelts, out-migration of the rural population and environmental problems will lead to total collapse. With global warming, water in the Great Plains is expected to become scarcer, and although improvements in irrigation efficiency may slow depletion of the Ogallala aquifer, ultimately the acreage under irrigation must decrease to levels that can be sustained by natural recharge and reliable surface flows. 23 refs., 2 figs

  5. Nucleation of Waterfalls at Fault Scarps Temporarily Shielded By Alluvial Fan Aggradation.

    Science.gov (United States)

    Malatesta, L. C.; Lamb, M. P.

    2014-12-01

    Waterfalls are important components of mountain river systems and they can serve as an agent to transfer tectonic, climatic, or authigenic signals upstream through a catchment. Retreating waterfalls lower the local base level of the adjacent hillslopes, and temporarily increase sediment delivery to the fluvial system. Their creation is often attributed to seismic ruptures, lithological boundaries, or the coalescence of multiple smaller steps. We explore here a mechanism for the nucleation of waterfalls that does not rely on sudden seismic slip but on the build-up of accumulated slip during periods of fault burial by fluvial aggradation. Alluvial fans are common features at the front of mountain ranges bound by normal or thrust faults. Climate change or internal forcing in the mountain catchment modifies the equilibrium slope of alluvial fans. When alluvial fans aggrade, they shield the active fault scarp from fluvial erosion allowing the scarp to grow undisturbed. The scarp may then be exposed when the channel incises into the fan exposing a new bedrock waterfall. We explore this mechanism analytically and using a numerical model for bedrock river incision and sediment deposition. We find that the creation of waterfalls by scarp burial is limited by three distinct timescales: 1) the critical timescale for the scarp to grow to the burial height, 2) the timescale of alluvial re-grading of the fan, and 3) the timescale of the external or internal forcing, such as climate change. The height of the waterfall is controlled by i) the difference in equilibrium alluvial-fan slopes, ii) the ratio of the respective fan and catchment sizes, iii) the catchment wide denudation rate, and iv) the fault slip rate. We test whether an individual waterfall could be produced by alluvial shielding of a scarp, and identify the tectonic, climatic, or authigenic nature of waterfalls using example field sites in the southwest United States.

  6. Enhancing flood hazard estimation methods on alluvial fans using an integrated hydraulic, geological and geomorphological approach

    Science.gov (United States)

    Mollaei, Zeinab; Davary, Kamran; Majid Hasheminia, Seyed; Faridhosseini, Alireza; Pourmohamad, Yavar

    2018-04-01

    Due to the uncertainty concerning the location of flow paths on active alluvial fans, alluvial fan floods could be more dangerous than riverine floods. The United States Federal Emergency Management Agency (FEMA) used a simple stochastic model named FAN for this purpose, which has been practiced for many years. In the last decade, this model has been criticized as a consequence of development of more complex computer models. This study was conducted on three alluvial fans located in northeast and southeast Iran using a combination of the FAN model, the hydraulic portion of the FLO-2D model, and geomorphological information. Initial stages included three steps: (a) identifying the alluvial fans' landforms, (b) determining the active and inactive areas of alluvial fans, and (c) delineating 100-year flood within these selected areas. This information was used as an input in the mentioned three approaches of the (i) FLO-2D model, (ii) geomorphological method, and (iii) FAN model. Thereafter, the results of each model were obtained and geographical information system (GIS) layers were created and overlaid. Afterwards, using a scoring system, the results were evaluated and compared. The goal of this research was to introduce a simple but effective solution to estimate the flood hazards. It was concluded that the integrated method proposed in this study is superior at projecting alluvial fan flood hazards with minimum required input data, simplicity, and affordability, which are considered the primary goals of such comprehensive studies. These advantages are more highlighted in underdeveloped and developing countries, which may well lack detailed data and financially cannot support such costly projects. Furthermore, such a highly cost-effective method could be greatly advantageous and pragmatic for developed countries.

  7. Geomorphological and cryostratigraphical analyses of the Zackenberg Valley, NE Greenland and significance of Holocene alluvial fans

    Science.gov (United States)

    Cable, Stefanie; Christiansen, Hanne H.; Westergaard-Nielsen, Andreas; Kroon, Aart; Elberling, Bo

    2018-02-01

    In High Arctic northern Greenland, future responses to climatic changes are poorly understood on a landscape scale. Here, we present a study of the geomorphology and cryostratigraphy in the Zackenberg Valley in NE Greenland (74°N) containing a geomorphological map and a simplified geocryological map, combined with analyses of 13 permafrost cores and two exposures. Cores from a solifluction sheet, alluvial fans, and an emerged delta were studied with regards to cryostructures, ice and total carbon contents, grain size distribution, and pore water electrical conductivity; and the samples were AMS 14C dated. The near-surface permafrost on slopes and alluvial fans is ice rich, as opposed to the ice-poor epigenetic permafrost in the emerged delta. Ground ice and carbon distribution are closely linked to sediment transport processes, which largely depend on lithology and topography. Holocene alluvial fans on the lowermost hillslopes, covering 12% of the study area, represent paleoenvironmental archives. During the contrasting climates of the Holocene, the alluvial fans continued to aggrade - through the warmer early Holocene Optimum, the colder late Holocene, and the following climate warming - and by 0.45 mm a- 1, on average. This is caused by three factors: sedimentation, ground ice aggradation, and vegetation growth and is reflected by AMS 14C dating and continuously alternating cryostructures. Highly variable sedimentation rates in space and time at the alluvial fans have been detected. This is also reflected by alternating lenticular and microlenticular cryostructures indicating syngenetic permafrost aggradation during sedimentation with suspended and organic-matrix cryostructures indicating quasi-syngenetic permafrost aggradation in response to vegetation growth in periods with reduced or no sedimentation. Over time, this causes organic matter to become buried, indicating that alluvial fans represent effective carbon sinks that have previously been overlooked.

  8. Integrating channel form and processes in the Gangetic plains rivers: Implications for geomorphic diversity

    Science.gov (United States)

    Roy, N. G.; Sinha, R.

    2018-02-01

    Geomorphic diversity at a variety of spatial and temporal scales has been studied in the western Ganga plains (WGP), India, to isolate the dominating factors at each scale that have the potential to cause major geomorphic change. The Ganga River and its major tributaries draining the WGP have been investigated in terms of longitudinal, cross-sectional, and planform morphology to assess the influence of potential controls such as climate, geology, topography, land use, hydrology, and sediment transport. These data were then compared with those from the rivers draining the eastern Ganga plains (EGP) to understand the geomorphic diversity across the Ganga plains and the causal factors. Our investigations suggest that in-channel geomorphic diversity over decadal scale in rivers with low width-to-depth (W/D) ratio is caused by periodic incision/aggradation, but it is driven by channel avulsion in rivers characterized by high W/D ratio. Similarly, planform (reach-scale) parameters such as sinuosity and braid-channel-ratio are influenced by intrinsic factors such as changes in hydrological conditions and morphodynamics (cutoffs, small-scale avulsion) that are in turn impacted by natural and human-induced factors. Finally, we have isolated the climatic and hydrologic effects on the longitudinal profile concavity of alluvial trunk channels in tectonically stable and unstable landscapes. We demonstrate that the rivers flowing through a tectonically stable landscape are graded in nature where higher discharge tends to create more concave longitudinal profiles compared to those in tectonically unstable landscape at 103-year scale.

  9. Late Pleistocene dune-sourced alluvial fans in coastal settings: Sedimentary facies and related processes (Mallorca, Western Mediterranean)

    Science.gov (United States)

    Pomar, F.; del Valle, L.; Fornós, J. J.; Gómez-Pujol, L.

    2018-05-01

    Aeolian-alluvial sedimentary interaction results in the formation of deposits characterized by typical alluvial sedimentary structures, but is composed of conspicuous amounts of aeolian sediments. The literature on this topic is limited and most works relate more with continental aeolian dunes or fluvial dune interference with fan bodies. Furthermore, there is a lack of examples of aeolian-alluvial sedimentary interference in coastal settings. In the western Mediterranean, there are many Pleistocene alluvial fan deposits built up partly by sediment originating from coastal dunes dismantled by alluvial streams. Very often, these deposits show a continuous sedimentary sequence through which we can derive the contribution and predominance of coastal, alluvial-colluvial and aeolian processes and their controls on landscape formation. This is an outstanding feature within coastal systems since it shows marine sediments reworked and integrated within coastal dune fields by aeolian transport, and the latter built up into alluvial fan bodies. In this sense, aeolian-alluvial interaction is the geomorphic-sedimentary expression of the coexistence and overlapping of alluvial and aeolian environments resulting in deposits sharing sedimentary features from both environments. The aim of this paper is to unravel the contribution of coastal dunes in the construction of alluvial fans bodies and identify the main sedimentary facies that constitute these deposits, as well as their climatic controls. For this reason, Es Caló fan (northern Mallorca) has been selected due to its well-exposed deposits exhibiting the alternation of aeolian, alluvial and colluvial deposits. Sedimentological and stratigraphic analyses based on 33 logs and complementary analyses demonstrate that most of the facies constituting the fan body are made up completely of marine bioclastic sands. These deposits record an alluvial fan sedimentary environment characterized by sediments inputs that do not proceed

  10. Seismic echo character northern Hatteras Abyssal Plain

    International Nuclear Information System (INIS)

    McCreery, C.J.; Laine, E.P.

    1985-01-01

    Latest efforts in echo-character mapping of the northern Hatteras Abyssal Plain have discerned variations in thickness in a near-surface sedimentary sequence which has been designated seismic unit A. This unit probably represents the last episode of progradation of the Hatteras Deep Sea Fan in the southern part of the study area, and has infilled probable paleochannels from the Wilmington Canyon and Sohm Gap in the north. Unit A thins to a minimum in the central part of the plain, where older sediments come within 1 meter of the surface. Variations in the character of the surface reflector probably represent differing degrees of microtopography developed on a Late Pleistocene surface overlain by Holocene sediments. With the exception of one area identified as a relict surface outcropping in the western plain, this microtopography seems related to present-day thalweg locations on the abyssal plain. 11 references, 13 figures

  11. Southern Great Plains Atmospheric Radiation Measurement Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Southern Great Plains Atmospheric Radiation Measurement Site (SGP-ARM) is the oldest and largest of DOE's Arm sites. It was established in 1992. It consists of...

  12. flexural improvement of plain concrete beams strengthened

    African Journals Online (AJOL)

    Muhammad Nura Isa

    Results show significant improvement in both stiffness and load bearing capacity of plain concrete ... Various methods have been developed to increase their strength capacity by using .... obtained by carrying out uniaxial direct tensile strength.

  13. Geo-archaeological aspects of the Modena plain (Northern Italy

    Directory of Open Access Journals (Sweden)

    Doriano Castaldini

    2007-12-01

    Full Text Available This paper traces the various stages of geomorphological evolution of the plain area around Modena from the VIth millennium B.C.E. (Neolithic to the Present, through a reconstruction of the ancient landscape and human settlements.By means of a GIS platform, geomorphological investigations led to the implementation of a Microrelief Map, a Digital Elevation Model (DEM, a Map of Surface Deposits and a Geomorphological Map.The most striking altimetric features in the study area are the morphological changes of the Rivers Secchia and Panaro: south of Modena they run deep in the alluvial plain whereas north of the town they flow elevated over the plain. The surface lithology consists mainly of silt, with bands of sand and clay; mainly gravel deposits crop out only near southern tracks of the main Apennine watercourses. The geomorphological landscape is mainly characterised by alluvial fans, fluvial ridges paleo-riverbeds fluvial scarps, natural springs and some depressed areas; worth of note are also forms connected with human activity.There have been several attempts to cross–date geological and geomorphological evidence with archaeological data, on both detailed and wide territorial scales. A further advancement can now be attempted by comparing data obtained from systematic research on fluvial forms with data contained in the archives.In the area studied, some 800 archaeological sites were identified and catalogued. Such a high number of archaeological sites can give a great deal more information than is found in any other place in northern Italy.The research took into account the overlapping of archaeological and geomorphological data, with the implementation into a GIS (ArcGis 8.3 of geoarchaeological maps divided in main periods and here represented from the Neolithic to the to Iron Age and from Roman period to the Early Middle Ages. The dating thus obtained for fluvial forms was mainly based on the relationship between these forms and

  14. Defining 'plain language' in contemporary South Africa | Cornelius ...

    African Journals Online (AJOL)

    Defining the concept 'plain language' has been hugely problematic since the origins of the socalled Plain Language Movement in the 1970s in the United States and elsewhere in the world. Definitions of 'plain language' abound, yet James (2008: 6) warns, in relation to plain language practitioners, that “we can't yet call ...

  15. 44 CFR 10.14 - Flood plains and wetlands.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44 CFR...

  16. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    de Hamer, W.; Love, D.; Owen, R.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2008-01-01

    Groundwater use by accessing alluvial aquifers of non-perennial rivers can be an important additional water resource in the semi-arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper-Mnyabezi catchment under current conditions

  17. Potential water supply of a small reservoir and alluvial aquifer system in southern Zimbabwe

    NARCIS (Netherlands)

    de Hamer, W.; Love, D.; Owen, R.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2007-01-01

    Groundwater use by accessing alluvial aquifers of non‐perennial rivers can be an important additional water resource in the semi‐arid region of southern Zimbabwe. The research objective of the study was to calculate the potential water supply for the upper‐Mnyabezi catchment under current conditions

  18. Reference conditions for old-growth redwood restoration on alluvial flats

    Science.gov (United States)

    Christa M. Dagley; John-Pascal. Berrill

    2012-01-01

    We quantified structural attributes in three alluvial flat old-growth coast redwood stands. Tree size parameters and occurrences of distinctive features (e.g., burls, goose pens) were similar between stands. Occurrence of distinctive features was greater among larger trees. Tree sizefrequency distributions conformed to a reverse-J diameter distribution. The range of...

  19. Bottomland Hardwoods of the Mississippi Alluvial Valley: Characteristics and Management of Natural Function, Structure, and Composition

    Science.gov (United States)

    Paul B. Hamel; Thomas L. Foti; [Editors

    2001-01-01

    A symposium entitled "Bottomland hardwoods of the Mississippi Alluvial Valley: characteristics and management of natural function, structure, and composition" convened on October 28, 1995, as part of the Natural Areas Conference, October 25-28, 1995, In Fayetteville, AR. The symposium's goal was to provide informatibn that managers need to begin...

  20. Contrasting morphodynamics in alluvial fans and fan deltas: effect of the downstream boundary

    NARCIS (Netherlands)

    Dijk, M. van; Kleinhans, M.G.; Postma, G.; Kraal, E.

    2012-01-01

    Alluvial fans and fan deltas can, in principle, have exactly the same upstream conditions, but fan deltas by definition have ponding water at their downstream boundary. This ponding creates effects on the autogenic behaviour of fan deltas, such as backwater adaptation, mouth bars and backward

  1. Transport of Escherichia Coli and solutes during waste water infiltration in an urban alluvial aquifer

    NARCIS (Netherlands)

    Foppen, J.W.A.; van Herwerden, M.; Kebtie, M.; Noman, A.; Schrijven, J.F.; Stuijfzand, P.J.; Uhlenbrook, S.

    2008-01-01

    Recharge of waste water in an unconsolidated poorly sorted alluvial aquifer is a complex process, both physically and hydrochemically. The aim of this paper is to analyse and conceptualise vertical transport mechanisms taking place in an urban area of extensive wastewater infiltration by analysing

  2. Historical trajectories and restoration strategies for the Mississippi River alluvial valley

    Science.gov (United States)

    Brice B. Hanberry; John M. Kabrick; Hong S. He; Brian J. Palik

    2012-01-01

    Unlike upland forests in the eastern United States, little research is available about the composition and structure of bottomland forests before Euro-American settlement. To provide a historical reference encompassing spatial variation for the Lower Mississippi River Alluvial Valley, we quantified forest types, species distributions, densities, and stocking of...

  3. INFLUENCE OF SEDIMENT SUPPLY, LITHOLOGY, AND WOOD DEBRIS ON THE DISTRIBUTION OF BEDROCK AND ALLUVIAL CHANNELS

    Science.gov (United States)

    Field surveys in the Willapa River basin, Washington State, indicate that the drainage area?channel slope threshold describing the distribution of bedrock and alluvial channels is influenced by the underlying lithology and that local variations in sediment supply can overwhelm ba...

  4. Dry season diets of sympatric ungulates in lowland Nepal: competition and facilitation in alluvial tall grasslands

    NARCIS (Netherlands)

    Wegge, P.; Shrestha, A.K.; Moe, S.R.

    2006-01-01

    Based on microhistological analyses of faecal material, we compared the early dry season diets of greater one-horned rhinoceros Rhinoceros unicornis, swamp deer Cervus duvauceli and hog deer Axis porcinus, which inhabit the same alluvial grassland habitat complex in lowland Nepal. Their diets were

  5. Calibration of a neutron probe for determining the humidity in deep alluvial soils

    International Nuclear Information System (INIS)

    Ferrer, A.; Rivero, H.; Lopez, F.; Cantillo, O.

    1993-01-01

    Preliminary data for the calibration of a neutron probe in deep alluvial soils for determining the humidity are reported. Comparisons of Neutron flow behaviour with the depth of the land are established. A characteristic curve of amount of detected neutrons according to the humidity percentage (from 50 to 100 % of the field humidity) is obtained

  6. Spatial patterns of lacustrine fish assemblages in a catchment of the Mississippi Alluvial Valley

    Science.gov (United States)

    Andrews, Caroline S.; Miranda, Leandro E.; Goetz, Daniel B.; Kroger, Robert

    2014-01-01

    In the alluvial valley of the lower Mississippi River, floodplain lakes form isolated aquatic fragments that retain differing degrees of connectivity to neighbouring rivers. Within these floodplain lakes it was hypothesized that fish species composition, relative abundance, and biodiversity metrics would be shaped largely by aquatic connectivity within a catchment.

  7. Hydrology of the alluvial, buried channel, basal Pleistocene and Dakota aquifers in west-central Iowa

    Science.gov (United States)

    Runkle, D.L.

    1985-01-01

    A ground-water resources investigation in west-central Iowa indicates that water is available from alluvial, buried channel, basal Pleistocene, and Dakota aquifers. The west-central Iowa area includes Audubon, Carrol1, Crawford, Greene, Guthrie, Harrison, Monona, and Shelby Counties.

  8. Strontium isotope geochemistry of alluvial groundwater: a tracer for groundwater resources characterisation

    Directory of Open Access Journals (Sweden)

    P. Négrel

    2004-01-01

    Full Text Available This study presents strontium isotope and major ion data of shallow groundwater and river water from the Ile du Chambon catchment, located on the Allier river in the Massif Central (France. There are large variations in the major-element contents in the surface- and groundwater. Plotting of Na vs. Cl contents and Ca, Mg, NO3, K, SO4, HCO3, Sr concentrations reflect water–rock interaction (carbonate dissolution for Ca, Mg, HCO3 and Sr because the bedrock contains marly limestones, agricultural input (farming and fertilising and sewage effluents (for NO3, K, SO4, although some water samples are unpolluted. Sr contents and isotope ratios (87Sr/86Sr vary from 0.70892 to 0.71180 along the hydrological cycle in the groundwater agree with previous work on groundwater in alluvial aquifers in the Loire catchment. The data plot along three directions in a 87Sr/86Sr v. 1/Sr diagram as a result of mixing, involving at least three geochemical signatures–Allier river water, and two distinct signatures that might be related to different water-rock interactions in the catchment. Mixing proportions are calculated and discussed. The alluvial aquifer of the Ile du Chambon catchment is considered, within the Sr isotope systematic, in a larger scheme that includes several alluvial aquifers of the Loire Allier catchment. Keywords: : Loire river, major and trace elements, Sr isotopic ratio, alluvial aquifer, hydrology

  9. Definition of the filtration coefficient in the alluvial sands area of the Chernobyl NPP industrial site

    International Nuclear Information System (INIS)

    Panasyuk, N.I.

    2014-01-01

    Calculations of the filter coefficients of the alluvial soils of the first unconfined aquifer according roses pumping water from wells perfect. Filtration coefficient is one of the main parameters of the soil, which has a significant impact on the reliability of the forecasts of changes. Radio- hydrogeological conditions of the area and water calculations

  10. Litterfall in the hardwood forest of a minor alluvial-floodplain

    Science.gov (United States)

    Calvin E. Meier; John A. Stanturf; Emile S. Gardiner

    2006-01-01

    within mature deciduous forests, annual development of foliar biomass is a major component of aboveground net primary production and nutrient demand. As litterfall, this same foliage becomes a dominant annual transfer of biomass and nutrients to the detritus pathway. We report litterfall transfers of a mature bottomland hardwood forest in a minor alluvial-floodplain...

  11. Clogging of water supply wells in alluvial aquifers by mineral incrustations, central Serbia

    Directory of Open Access Journals (Sweden)

    Majkić-Dursun Brankica

    2015-01-01

    Full Text Available The formation of incrustations on public water supply well screens reduces their performance considerably. The incrustations increase hydraulic losses, reduce the capacity of the well and screen, affect the quality of the pumped water and increase maintenance costs. In alluvial environments, the most common deposits are iron and manganese hydroxides. However, the rates of formation, compositions and levels of crystallization vary, depending on the geochemical characteristics of the alluvial environment, the microbiological characteristics of the groundwater and the abstraction method. Samples of 15 incrustations were collected from wells that tap shallow alluvial aquifers and were found to be dominated by iron. XRD analyses detected low-crystalline ferrihydrite and manganese hydroxide in the samples collected from the water supply source at Trnovče (Velika Morava alluvial. The incrustations from the Belgrade Groundwater Source revealed the presence of ferrihydrite and a substantial amount of goethite α-FeOOH. Apart from goethite, greigite (Fe3S4 was detected in three samples, while one sample additionally contained bernalite Fe(OH3 and monoclinic sulfur S8. Among carbonates, only siderite was detected. Iron oxidizing bacteria generally catalyze deposition processes in wells, while sulfate reducing bacteria (SRB play a role in the biogenic formation of greigite. Determining the nature of the deposited material allows better selection of rehabilitation chemicals and procedure. [Projekat Ministarstva nauke Republike Srbije, br. TR37014

  12. Magnetic properties of alluvial soils contaminated with lead, zinc and cadmium

    Czech Academy of Sciences Publication Activity Database

    Petrovský, Eduard; Kapička, Aleš; Jordanova, Neli; Borůvka, L.

    2001-01-01

    Roč. 48, č. 2 (2001), s. 12-136 ISSN 0926-9851 R&D Projects: GA ČR GA205/96/0260 Institutional research plan: CEZ:AV0Z3012916 Keywords : magnetic properties * alluvial soil * heavy metals Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.390, year: 2001

  13. Carbon sequestration resulting from bottomland hardwood afforestation in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Bertrand F. Nero; Richard P. Maiers; Janet C. Dewey; Andrew J. Londo

    2010-01-01

    Increasing abandonment of marginal agricultural lands in the Lower Mississippi Alluvial Valley (LMAV) and rising global atmospheric carbon dioxide (CO2) levels create a need for better options of achieving rapid afforestation and enhancing both below and aboveground carbon sequestration. This study examines the responses of six mixtures of bottomland hardwood species...

  14. Timing and nature of alluvial fan and strath terrace formation in the Eastern Precordillera of Argentina

    Science.gov (United States)

    Hedrick, Kathryn; Owen, Lewis A.; Rockwell, Thomas K.; Meigs, Andrew; Costa, Carlos; Caffee, Marc W.; Masana, Eulalia; Ahumada, Emilio

    2013-11-01

    Sixty-eight 10Be terrestrial cosmogenic nuclide (TCN) surface exposure ages are presented to define the timing of alluvial fan and strath terrace formation in the hyper-arid San Juan region of the Argentine Precordillera. This region is tectonically active, and numerous fault scarps traverse Quaternary landforms. The three study sites, Marquesado strath complex, Loma Negra alluvial fan and Carpintería strath complex reveal a history of alluvial fan and strath terrace development over the past ˜225 ka. The Marquesado complex Q3m surface dates to ˜17 ± 3 ka, whereas the Loma Negra Q1ln, Q2ln, Q3ln, Q4ln, and Q5ln surfaces date to ˜24 ± 3 ka, ˜48 ± 2 ka, ˜65 ± 13 ka, ˜105 ± 21 ka, and ˜181 ± 29 ka, respectively. The Carpintería complex comprises eight surfaces that have been dated and include the Q1c (˜23 ± 3 ka), Q2c (˜5 ± 5 ka), Q3ac (˜25 ± 12 ka), Q3bc (˜29 ± 15 ka), Q4c (˜61 ± 12 ka), Q5c (˜98 ± 18 ka), Q6c (˜93 ± 18 ka), and Q7c (˜212 ± 37 ka). 10Be TCN depth profile data for the Loma Negra alluvial fan complex and Carpintería strath terrace complex, as well as OSL ages on some Carpintería deposits, aid in refining surface ages for comparison with local and global climate proxies, and additionally offer insights into inheritance and erosion rate values for TCNs (˜10 × 10410Be atoms/g of SiO2 and ˜5 m Ma-1, respectively). Comparison with other alluvial fan studies in the region show that less dynamic and older preserved surfaces occur in the Carpintería and Loma Negra areas with only younger alluvial fan surfaces preserved both to the north and south. These data in combination with that of other studies illustrate broad regional agreement between alluvial fan and strath terrace ages, which suggests that climate is the dominant forcing agent in the timing of terrace formation in this region.

  15. Characteristics and origin of Earth-mounds on the Eastern Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Tullis, J.A.

    1995-09-01

    Earth-mounds are common features on the Eastern Snake River Plain, Idaho. The mounds are typically round or oval in plan view, <0.5 m in height, and from 8 to 14 m in diameter. They are found on flat and sloped surfaces, and appear less frequently in lowland areas. The mounds have formed on deposits of multiple sedimentary environments. Those studied included alluvial gravel terraces along the Big Lost River (late Pleistocene/early Holocene age), alluvial fan segments on the flanks of the Lost River Range (Bull Lake and Pinedale age equivalents), and loess/slopewash sediments overlying basalt flows. Backhoe trenches were dug to allow characterization of stratigraphy and soil development. Each mound has features unique to the depositional and pedogenic history of the site; however, there are common elements to all mounds that are linked to the history of mound formation. Each mound has a {open_quotes}floor{close_quotes} of a sediment or basement rock of significantly different hydraulic conductivity than the overlying sediment. These paleosurfaces are overlain by finer-grained sediments, typically loess or flood-overbank deposits. Mounds formed in environments where a sufficient thickness of fine-grained sediment held pore water in a system open to the migration to a freezing front. Heaving of the sediment occurred by the growth of ice lenses. Mound formation occurred at the end of the Late Pleistocene or early in the Holocene, and was followed by pedogenesis. Soils in the mounds were subsequently altered by bioturbation, buried by eolian deposition, and eroded by slopewash runoff. These secondary processes played a significant role in maintaining or increasing the mound/intermound relief.

  16. Dating of river terraces along Lefthand Creek, western High Plains, Colorado, reveals punctuated incision

    Science.gov (United States)

    Foster, Melissa A.; Anderson, Robert S.; Gray, Harrison J.; Mahan, Shannon A.

    2017-10-01

    The response of erosional landscapes to Quaternary climate oscillations is recorded in fluvial terraces whose quantitative interpretation requires numerical ages. We investigate gravel-capped strath terraces along the western edge of Colorado's High Plains to constrain the incision history of this shale-dominated landscape. We use 10Be and 26Al cosmogenic radionuclides (CRNs), optically stimulated luminescence (OSL), and thermally transferred OSL (TT-OSL) to date three strath terraces, all beveled in shale bedrock and then deposited upon by Lefthand Creek, which drains the crystalline core of the Front Range. Our study reveals: (i) a long history (hundreds of thousands of years) of fluvial occupation of the second highest terrace, T2 (Table Mountain), with fluvial abandonment at 92 ± 3 ka; (ii) a brief occupation of a narrow and spatially confined terrace, T3, at 98 ± 7 ka; and (iii) a 10-25 thousand year period of cutting and fluvial occupation of a lower terrace, T4, marked by the deposition of a lower alluvial unit between 59 and 68 ka, followed by deposition of an upper alluvial package at 40 ± 3 ka. In conjunction with other recent CRN studies of strath terraces along the Colorado Front Range (Riihimaki et al., 2006; Dühnforth et al., 2012), our data reveal that long periods of lateral planation and fluvial occupation of strath terraces, sometimes lasting several glacial-interglacial cycles, are punctuated by brief episodes of rapid vertical bedrock incision. These data call into question what a singular terrace age represents, as the strath may be cut at one time (its cutting-age) and the terrace surface may be abandoned at a much later time (its abandonment age), and challenge models of strath terraces that appeal to simple pacing by the glacial-interglacial cycles.

  17. Characteristics and origin of Earth-mounds on the Eastern Snake River Plain, Idaho

    International Nuclear Information System (INIS)

    Tullis, J.A.

    1995-09-01

    Earth-mounds are common features on the Eastern Snake River Plain, Idaho. The mounds are typically round or oval in plan view, <0.5 m in height, and from 8 to 14 m in diameter. They are found on flat and sloped surfaces, and appear less frequently in lowland areas. The mounds have formed on deposits of multiple sedimentary environments. Those studied included alluvial gravel terraces along the Big Lost River (late Pleistocene/early Holocene age), alluvial fan segments on the flanks of the Lost River Range (Bull Lake and Pinedale age equivalents), and loess/slopewash sediments overlying basalt flows. Backhoe trenches were dug to allow characterization of stratigraphy and soil development. Each mound has features unique to the depositional and pedogenic history of the site; however, there are common elements to all mounds that are linked to the history of mound formation. Each mound has a open-quotes floorclose quotes of a sediment or basement rock of significantly different hydraulic conductivity than the overlying sediment. These paleosurfaces are overlain by finer-grained sediments, typically loess or flood-overbank deposits. Mounds formed in environments where a sufficient thickness of fine-grained sediment held pore water in a system open to the migration to a freezing front. Heaving of the sediment occurred by the growth of ice lenses. Mound formation occurred at the end of the Late Pleistocene or early in the Holocene, and was followed by pedogenesis. Soils in the mounds were subsequently altered by bioturbation, buried by eolian deposition, and eroded by slopewash runoff. These secondary processes played a significant role in maintaining or increasing the mound/intermound relief

  18. Groundwater quality in alluvial and prolluvial areas under the influence of irrigated agriculture activities.

    Science.gov (United States)

    Kovacevik, Biljana; Boev, Blazo; Panova, Vesna Zajkova; Mitrev, Sasa

    2016-12-05

    The aim of this study was to investigate the groundwater pollution from alluvial aquifers lying under surface agriculture activities in two geologically different areas: alluvial and prolluvial. The groundwater in investigated areas is neutral to alkaline (pH 7.05-8.45), and the major dissolved ions are bicarbonate and calcium. Groundwater samples from the alluvial area are characterized by nitrate concentration above the national maximum concentration limit (MCL) at 20.5% of samples [mean value (Me) 6.31 mg/L], arsenic concentrations greater than national MCL at 35.6% of investigated samples (Me 12.12 µg/L) and elevated concentrations of iron (Me 202.37 µg/L) and manganese (Me 355.22 µg/L) at 22.7% and 81% of investigated samples, respectively. Groundwater samples from the prolluvial area did not show significantly elevated concentrations of heavy metals, but the concentration of nitrate was considerably higher (Me 65.06 mg/L). Factor analysis positively correlates As with Mn and Fe, suggesting its natural origin. Nitrate was found in positive correlation with SO 4 2- and Ni but in negative with NH 4 + , suggesting its anthropogenic origin and the relationship of these ions in the process of denitrification. The t-test analysis showed a significant difference between nitrate pollution of groundwater from alluvial and prolluvial areas. According to the chemical composition of groundwater, the process of denitrification is considered to be the main reason for the reduced presence of nitrate in the groundwater lying under alluvial deposits represented by chalk and sandstones. Denitrification in groundwater lying under prolluvial deposits represented by magmatic and metamorphic rock formations was not observed.

  19. Continental Environment of Triassic Alluvial Beds in the Northern North Sea Area: Core Examples from the Lunde Formation, Snorre Field

    Energy Technology Data Exchange (ETDEWEB)

    Nystuen, Johan Petter; Bergan, Morten

    1999-07-01

    Alluvial processes transport and deposit gravel, sand and mud in a series of depositional systems such as alluvial fans, fluvial channels, floodplain and lacustrine basins. In the northernmost part of the North Sea alluvial sandstones form major reservoir rocks in several oil fields in the Tampen Spur area. In the Snorre Field, the Norian- Early Rhaetian Lunde Formation has given a great database from exploration and production wells, seismic studies, reservoir modelling, production experience and comparative analogue studies on facies distribution, alluvial architecture, heterogeneities and reservoir properties of alluvial successions. The Lunde Formation is subdivided in three members, the lower, middle and upper Lunde members, with the upper member being the main part of the Lunde reservoir rocks. The scope of presenting core samples from the upper Lunde member is to demonstrate main alluvial facies and facies associations, how facies analysis proceeds into construction of conceptual fluvial models that in turn are fundamental in evaluation of reservoir heterogeneities and reservoir modelling. The upper Lunde member consists of repeated units of red and grey sandstone and mudstone. Sandstones are dominantly medium-grained with common range from coarse- to very fine-grained. A basic building stone of the alluvial succession consists of a thick single- or multi-storey sandstone body overlain by a thick mudstone unit. Such couplets form allostratigraphic units and define the main reservoir zones.

  20. Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

    Science.gov (United States)

    Wellman, Tristan

    2015-01-01

    The South Platte River and underlying alluvial aquifer form an important hydrologic resource in northeastern Colorado that provides water to population centers along the Front Range and to agricultural communities across the rural plains. Water is regulated based on seniority of water rights and delivered using a network of administration structures that includes ditches, reservoirs, wells, impacted river sections, and engineered recharge areas. A recent addendum to Colorado water law enacted during 2002-2003 curtailed pumping from thousands of wells that lacked authorized augmentation plans. The restrictions in pumping were hypothesized to increase water storage in the aquifer, causing groundwater to rise near the land surface at some locations. The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board and the Colorado Water Institute, completed an assessment of 60 years (yr) of historical groundwater-level records collected from 1953 to 2012 from 1,669 wells. Relations of "high" groundwater levels, defined as depth to water from 0 to 10 feet (ft) below land surface, were compared to precipitation, river discharge, and 36 geographic and administrative attributes to identify natural and human controls in areas with shallow groundwater.

  1. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting

    Science.gov (United States)

    Fogg, Graham E.; Noyes, Charles D.; Carle, Steven F.

    Information on sediment texture and spatial continuity are inherent to sedimentary depositional facies descriptions, which are therefore potentially good predictors of spatially varying hydraulic conductivity (K). Analysis of complex alluvial heterogeneity in Livermore Valley, California, USA, using relatively abundant core descriptions and field pumping-test data, demonstrates a depositional-facies approach to characterization of subsurface heterogeneity. Conventional textural classifications of the core show a poor correlation with K; however, further refinement of the textural classifications into channel, levee, debris-flow, and flood-plain depositional facies reveals a systematic framework for spatial modeling of K. This geologic framework shows that most of the system is composed of very low-K flood-plain materials, and that the K measurements predominantly represent the other, higher-K facies. Joint interpretation of both the K and geologic data shows that spatial distribution of K in this system could not be adequately modeled without geologic data and analysis. Furthermore, it appears that K should not be assumed to be log-normally distributed, except perhaps within each facies. Markov chain modeling of transition probability, representing spatial correlation within and among the facies, captures the relevant geologic features while highlighting a new approach for statistical characterization of hydrofacies spatial variability. The presence of fining-upward facies sequences, cross correlation between facies, as well as other geologic attributes captured by the Markov chains provoke questions about the suitability of conventional geostatistical approaches based on variograms or covariances for modeling geologic heterogeneity. Résumé Les informations sur la texture des sédiments et leur continuité spatiale font partie des descriptions de faciès sédimentaires de dépôt. Par conséquent, ces descriptions sont d'excellents prédicteurs potentiels des

  2. The role of discharge variability in the formation and preservation of alluvial sediment bodies

    Science.gov (United States)

    Fielding, Christopher R.; Alexander, Jan; Allen, Jonathan P.

    2018-03-01

    Extant, planform-based facies models for alluvial deposits are not fully fit for purpose, because they over-emphasise plan form whereas there is little in the alluvial rock record that is distinctive of any particular planform, and because the planform of individual rivers vary in both time and space. Accordingly, existing facies models have limited predictive capability. In this paper, we explore the role of inter-annual peak discharge variability as a possible control on the character of the preserved alluvial record. Data from a suite of modern rivers, for which long-term gauging records are available, and for which there are published descriptions of subsurface sedimentary architecture, are analysed. The selected rivers are categorized according to their variance in peak discharge or the coefficient of variation (CVQp = standard deviation of the annual peak flood discharge over the mean annual peak flood discharge). This parameter ranges over the rivers studied between 0.18 and 1.22, allowing classification of rivers as having very low ( 0.90) annual peak discharge variance. Deposits of rivers with very low and low peak discharge variability are dominated by cross-bedding on various scales and preserve macroform bedding structure, allowing the interpretation of bar construction processes. Rivers with moderate values preserve mostly cross-bedding, but records of macroform processes are in places muted and considerably modified by reworking. Rivers with high and very high values of annual peak discharge variability show a wide range of bedding structures commonly including critical and supercritical flow structures, abundant in situ trees and transported large, woody debris, and their deposits contain pedogenically modified mud partings and generally lack macroform structure. Such a facies assemblage is distinctively different from the conventional fluvial style recorded in published facies models but is widely developed both in modern and ancient alluvial

  3. Aerial Transient Electromagnetic Surveys of Alluvial Aquifers in Rural Watersheds of Arizona

    Science.gov (United States)

    Pool, D. R.; Callegary, J. B.; Groom, R. W.

    2006-12-01

    Development in rural areas of Arizona has led the State of Arizona (Arizona Department of Water Resources), in cooperation with the Arizona Water Science Center of the U.S. Geological Survey, to sponsor investigations of the hydrogeologic framework of several alluvial-basin aquifers. An efficient method for mapping the aquifer extent and lithology was needed due to sparse subsurface information. Aerial Transient Electro-Magnetic (ATEM) methods were selected because they can be used to quickly survey large areas and with a great depth of investigation. Both helicopter and fixed-wing ATEM methods are available. A fixed-wing method (GEOTEM) was selected because of the potential for a depth of investigation of 300 m or more and because previous surveys indicated the method is useful in alluvial basins in southeastern Arizona. About 2,900 km of data along flight lines were surveyed across five alluvial basins, including the Middle San Pedro and Willcox Basins in southeastern Arizona, and Detrital, Hualapai, and Sacramento Basins in northwestern Arizona. Data initially were analyzed by the contractor (FUGRO Airborne Surveys) to produce conductivity-depth-transforms, which approximate the general subsurface electrical-property distribution along profiles. Physically based two-dimensional physical models of the profile data were then developed by PetRos- Eikon by using EMIGMA software. Hydrologically important lithologies can have different electrical properties. Several types of crystalline and sedimentary rocks generally are poor aquifers that have low porosity and high electrical resistivity. Good alluvial aquifers of sand and gravel generally have an intermediate electrical resistivity. Poor aquifer materials, such as silt and clay, and areas of poor quality water have low electrical resistivity values. Several types of control data were available to constrain the models including drill logs, electrical logs, water levels , and water quality information from wells; and

  4. Capturing and modelling high-complex alluvial topography with UAS-borne laser scanning

    Science.gov (United States)

    Mandlburger, Gottfried; Wieser, Martin; Pfennigbauer, Martin

    2015-04-01

    Due to fluvial activity alluvial forests are zones of highest complexity and relief energy. Alluvial forests are dominated by new and pristine channels in consequence of current and historic flood events. Apart from topographic features, the vegetation structure is typically very complex featuring, both, dense under story as well as high trees. Furthermore, deadwood and debris carried from upstream during periods of high discharge within the river channel are deposited in these areas. Therefore, precise modelling of the micro relief of alluvial forests using standard tools like Airborne Laser Scanning (ALS) is hardly feasible. Terrestrial Laser Scanning (TLS), in turn, is very time consuming for capturing larger areas as many scan positions are necessary for obtaining complete coverage due to view occlusions in the forest. In the recent past, the technological development of Unmanned Arial Systems (UAS) has reached a level that light-weight survey-grade laser scanners can be operated from these platforms. For capturing alluvial topography this could bridge the gap between ALS and TLS in terms of providing a very detailed description of the topography and the vegetation structure due to the achievable very high point density of >100 points per m2. In our contribution we demonstrate the feasibility to apply UAS-borne laser scanning for capturing and modelling the complex topography of the study area Neubacher Au, an alluvial forest at the pre-alpine River Pielach (Lower Austria). The area was captured with Riegl's VUX-1 compact time-of-flight laser scanner mounted on a RiCopter (X-8 array octocopter). The scanner features an effective scan rate of 500 kHz and was flown in 50-100 m above ground. At this flying height the laser footprint is 25-50 mm allowing mapping of very small surface details. Furthermore, online waveform processing of the backscattered laser energy enables the retrieval of multiple targets for single laser shots resulting in a dense point cloud of

  5. Stratigraphy of the Martian northern plains

    Science.gov (United States)

    Tanaka, K. L.

    1993-01-01

    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  6. Holocene tectono-geomorphic evolution of parts of the Upper and Middle Gangetic plains, India

    Science.gov (United States)

    Pati, Pitambar; Parkash, B.; Awasthi, A. K.; Acharya, Vivekanand

    2011-05-01

    alluvial fans on this block. The Gandak-Kosi block is marked by a set of seven thrust splays off the Himalayan Frontal Thrust (HFT) in the footwall. Activity of these thrust splays in the foothill region caused progradation of the gravel piedmont and thus developed the widest piedmont zone (124 km) in the Gangetic plains. This is the first report of gravel piedmont progradation from a modern environment and role of thrust splays in such a progradation. In the southernmost part of this block, the continuous occurrence of terminal fans over a length of 140 km south of the South Muzaffarpur Fault forms a terminal fan piedmont/bajada. Orientation of the faults was used to interpret compression from the SW in the Ghaghara-Rapti Interfluve Plain in the west since ~ 10 Ka and compression from the south in the Gandak-Kosi interfan region in the east after 4.5 Ka. The Rapti-Gandak region in the central part shows the effects of mainly compression from the SW and compression from the south at different times. In addition to terminal fans formed because of low relief terrain features created by the activity of faults by involvement of the entire discharge of small meandering/braided streams, a new type of fan formed by splays from a large river on the downthrown sides of faults, called 'splay terminal fans' is observed from the Rapti-Gandak block.

  7. Coastal geomorphology of the Martian northern plains

    Science.gov (United States)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

    1993-01-01

    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  8. Imaging normal faults in alluvial fans using geophysical techniques: Field example from the coast of Gulf of Aqaba, Saudi Arabia

    KAUST Repository

    Hanafy, Sherif M.; Jonsson, Sigurjon; Klinger, Yann

    2014-01-01

    In this work we use geophysical methods to locate and characterize active faults in alluvial sediments. Since only subtle material and velocity contrasts are expected across the faults, we used seismic refraction tomography and 2D resistivity

  9. Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

    1999-04-28

    The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

  10. Design of alluvial Egyptian irrigation canals using artificial neural networks method

    Directory of Open Access Journals (Sweden)

    Hassan Ibrahim Mohamed

    2013-06-01

    Full Text Available In the present study, artificial neural networks method (ANNs is used to estimate the main parameters which used in design of stable alluvial channels. The capability of ANN models to predict the stable alluvial channels dimensions is investigated, where the flow rate and sediment mean grain size were considered as input variables and wetted perimeter, hydraulic radius, and water surface slope were considered as output variables. The used ANN models are based on a back propagation algorithm to train a multi-layer feed-forward network (Levenberg Marquardt algorithm. The proposed models were verified using 311 data sets of field data collected from 61 manmade canals and drains. Several statistical measures and graphical representation are used to check the accuracy of the models in comparison with previous empirical equations. The results of the developed ANN model proved that this technique is reliable in such field compared with previously developed methods.

  11. Influence of geologic structure on alluvial sedimentation in northwestern Yucca Flat, Nye County, Nevada

    International Nuclear Information System (INIS)

    Wagoner, J.L.

    1983-01-01

    Using downhole photography, alluvial sediments are described in 5 emplacement holes in northwestern Yucca Flat. The holes are located on or near the Grouse Canyon fan. The 3 most proximally located holes contain the coarsest sediments and display a general decrease in grain size in the downfan direction. The 2 most distally located holes contain fine-grained distal facies sediment in the upper parts of the holes and coarse-grained proximal facies gravels lower in the holes. The proximal gravels in the lower half of the sections were derived from the gravity high, a north-south-trending horst which was exposed early during the history of Yucca Flat basin. Alluvial sedimentation eventually exceeded uplift of the horst, which was buried by distal facies sediments, derived from the western basin margin

  12. Radiocarbon dating of floodplain and young terraces alluvial sediments of Latvia rivers

    International Nuclear Information System (INIS)

    Eberhards, G.; Saltupe, B.

    2000-01-01

    This paper include new information about alluvial sediments structure and radiocarbon data of some Latvia free-meandering rivers (Gauja, Ogre, Liela and Maza Jugla, Daugava) floodplains and first terraces. In this present study we examined Gauja river floodplains in the different geomorphological and geological areas. Radiocarbon dating add the fact that the high level floodplain (4-5 m) formation and sediment accumulation take place 3000-5000 years before present (BP) middle level floodplains formed 1500-2100 years BP. Investigations show that one river terraces and floodplains with same relative height have a several absolute age. The rivers crossed same hypsometrical regions (highlands, lowlands) downstream in lowlands alluvial terraces performed as floodplains or from from floodplains to terraces with same height. On the highest, middle and in the lower parts of the rivers with free - meandering channel to - day the dynamic balance of the channel processes exits 4000-5000 years. (author)

  13. Quantitative palaeodrainage analysis in the Pleistocene of the Po Plain (Italy)

    Science.gov (United States)

    Vezzoli, G.; Garzanti, E.; Sciunnach, D.

    2009-04-01

    During the Pleistocene, Po Plain deposits recorded repeated waxing and waning of Alpine ice caps, and thus provide an excellent opportunity to investigate the interactions between pronounced climatic fluctuations and background tectonic activity (Scardia et al., 2006), resulting in frequent changes of drainage patterns. A high-resolution Pleistocene stratigraphy, with a complete sedimentological, paleontological, petrographic-mineralogical, magneto-stratigraphic, and seismic data base, was recently obtained from eleven continuous cores drilled in the Lombardy Po Plain north of the Po River (ENI and Regione Lombardia, 2002). In the present study we focus on two cores in the proximal (Cilavegna) and distal plain (Pianengo), which best exemplify the drastic change in sedimentary systems and drainage patterns associated with the onset of major Pleistocene glaciations in the Alps (˜870ky; Muttoni et al., 2003). This climatic event is recorded by a regional unconformity (named R-unconformity by Muttoni et al., 2003), traced all across the Po Basin and encountered at -81 m depth in the Pianengo Core and at -98 m depth in the Cilavegna Core. The Cilavegna Core consists of metamorphiclastic floodplain sediments, capped by the R-unconformity and overlain by quartzofeldspathic braidplain deposits. The Pianengo Core consists of metamorphiclastic deltaic to floodpain sediments, capped by the R-unconformity and overlain by alluvial-fan gravels rich in carbonate pebbles; another unconformity at -39 m depth is overlain by metamorphiclastic braidplain deposits. Our quantitative approach to paleodrainage analysis is based on comprehensive information obtained from modern settings (Garzanti et al., 2004; 2006). End-member modelling and similarity analysis allows us to objectively compare detrital modes from modern and ancient deposits, and to reconstruct the evolution of sediment pathways through geologic time (Vezzoli and Garzanti 2009). The Cilavegna Core documents stepwise south

  14. Moessbauer study of the transformations occurring in egyptian alluvial and calcareous clays during firing

    International Nuclear Information System (INIS)

    Sallam, H.A.; Gomma, N.S.; El Meligy, W.M.; Eissa, N.A.

    1994-01-01

    Egyptian alluvial and calcareous clay samples, which are used in pottery production, were heated at different temperatures in air up to 1100 degree C. The physicochemical transformations were followed up and could be separated in two main stages; i) the dehydroxilation, of the clay mineral, stage for firing up to 700 degree C, ii) the second stage for firing at 900 degree C and higher. In the later stage the effect of calcium content was very pronounced. 2 figs

  15. Investigating selective transport and abrasion on an alluvial fan using quantitative grain size and shape analysis

    Science.gov (United States)

    Litwin, K. L.; Jerolmack, D. J.

    2011-12-01

    Selective sorting and abrasion are the two major fluvial processes that are attributed to the downstream fining of sediments in rivers and alluvial fans. Selective transport is the process by which smaller grains are preferentially transported downstream while larger grains are deposited closer to the source. Abrasion is defined by the production of fine sediments and sand that occurs by saltation of gravel, where particle-to-particle collisions supply the energy required to break apart grains. We hypothesize that abrasion results in the gradual fining of large grains and the production of fine sands and silts, while sorting accounts for the differences in transport of these two grain-size fractions produced from abrasion, thereby creating the abrupt gravel-sand transition observed in many channel systems. In this research, we explore both selective transport and abrasion processes on the Dog Canyon alluvial fan near Alamogordo, New Mexico. We complete an extensive grain size analysis down the main channel of the fan employing an image-based technique that utilizes an autocorrelation process. We also characterize changes in grain shape using standard shape parameters, as well as Fourier analysis, which allows the study of contributions of grain roughness on a variety of length scales. Sorting appears to dominate the upper portion of the fan; the grain-size distribution narrows moving downstream until reaching a point of equal mobility, at which point sorting ceases. Abrasion exerts a subtle but persistent effect on grains during transport down the fan. Shape analysis reveals that particles become more rounded by the removal of small-scale textural features, a process that is expected to only modestly influence grain size of gravel, but should produce significant quantities of sand. This study provides a better understanding of the importance of grain abrasion and sorting on the downstream fining of channel grains in an alluvial fan, as well as an improved knowledge

  16. Length scale hierarchy and spatiotemporal change of alluvial morphologies over the Selenga River delta, Russia

    Science.gov (United States)

    Dong, T. Y.; Nittrouer, J.; McElroy, B. J.; Ma, H.; Czapiga, M. J.; Il'icheva, E.; Pavlov, M.; Parker, G.

    2017-12-01

    The movement of water and sediment in natural channels creates various types of alluvial morphologies that span length scales from dunes to deltas. The behavior of these morphologies is controlled microscopically by hydrodynamic conditions and bed material size, and macroscopically by hydrologic and geological settings. Alluvial morphologies can be modeled as either diffusive or kinematic waves, in accordance with their respective boundary conditions. Recently, it has been shown that the difference between these two dynamic behaviors of alluvial morphologies can be characterized by the backwater number, which is a dimensionless value normalizing the length scale of a morphological feature to its local hydrodynamic condition. Application of the backwater number has proven useful for evaluating the size of morphologies, including deltas (e.g., by assessing the preferential avulsion location of a lobe), and for comparing bedform types across different fluvial systems. Yet two critical questions emerge when applying the backwater number: First, how do different types of alluvial morphologies compare within a single deltaic system, where there is a hydrodynamic transition from uniform to non-uniform flow? Second, how do different types of morphologies evolve temporally within a system as a function of changing water discharge? This study addresses these questions by compiling and analyzing field data from the Selenga River delta, Russia, which include measurements of flow velocity, channel geometry, bed material grain size, and channel slope, as well as length scales of various morphologies, including dunes, island bars, meanders, bifurcations, and delta lobes. Data analyses reveal that the length scale of morphologies decrease and the backwater number increases as flow transitions from uniform to non-uniform conditions progressing downstream. It is shown that the evaluated length scale hierarchy and planform distribution of different morphologies can be used to

  17. Upstream effects of dams on alluvial channels: state-of-the-art and future challenges

    Science.gov (United States)

    Liro, Maciej

    2017-04-01

    More than 50,000 large dams (with the height above 15 m) operate all over the world and, thus, they significantly disturb water and sediment transport in river systems. These disturbances are recognized as one of the most important factors shaping river morphology in the Anthropocene. Downstream effects of dams have been well documented in numerous case studies and supported by predictions from existing models. In contrast, little is known on the upstream effects of dams on alluvial channels. This review highlights the lack of studies on sedimentological, hydromorphological and biogeomorphological adjustments of alluvial rivers in the base-level raised zones of backwater upstream of dam reservoirs where water level fluctuations occur. Up to date, it has been documented that backwater effects may facilitate fine and coarse sediment deposition, increase groundwater level, provide higher and more frequent channel and floodplain inundation and lead to significant morphological changes. But there have been no studies quantifying short- and long-term consequences of these disturbances for the hydromorphological and biogeomorphological feedbacks that control development of alluvial channels. Some recent studies carried out on gravel-bed and fine-grained bed rivers show that the above mentioned disturbances facilitate vegetation expansion on exposed channel sediments and floodplain influencing river morphology, which suggests that backwater area of alluvial rivers may be treated as the hotspot of bio-geomorphological changes in a fluvial system. To set the stage for future research on upstream effects of dams, this work presents the existing state-of-art and proposes some hypotheses which may be tested in future studies. This study was carried out within the scope of the Research Project 2015/19/N/ST10/01526 financed by the National Science Centre of Poland

  18. Habitat disturbance and hydrological parameters determine the body size and reproduction strategy of alluvial ground beetles

    OpenAIRE

    Gerisch, Michael

    2011-01-01

    Abstract Environmental variability is the main driver for the variation of biological characteristics (life-history traits) of species. Therefore, life-history traits are particularly suited to identify mechanistic linkages between environmental variability and species occurrence and can help in explaining ecological patterns. For ground beetles, few studies directly related species traits to environmental variables. This study aims to analyse how life-history traits of alluvial ground beetle...

  19. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    Science.gov (United States)

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  20. Impacts of hydroelectric dams on alluvial riparian plant communities in eastern Brazilian Amazonian

    Directory of Open Access Journals (Sweden)

    LEANDRO VALLE FERREIRA

    2013-09-01

    Full Text Available The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  1. Probabilistic risk assessment of nitrate groundwater contamination from greenhouses in Albenga plain (Liguria, Italy) using lysimeters.

    Science.gov (United States)

    Paladino, Ombretta; Seyedsalehi, Mahdi; Massabò, Marco

    2018-04-05

    The use of fertilizers in greenhouse-grown crops can pose a threat to groundwater quality and, consequently, to human beings and subterranean ecosystem, where intensive farming produces pollutants leaching. Albenga plain (Liguria, Italy) is an alluvial area of about 45km 2 historically devoted to farming. Recently the crops have evolved to greenhouses horticulture and floriculture production. In the area high levels of nitrates in groundwater have been detected. Lysimeters with three types of reconstituted soils (loamy sand, sandy clay loam and sandy loam) collected from different areas of Albenga plain were used in this study to evaluate the leaching loss of nitrate (NO 3 - ) over a period of 12weeks. Leaf lettuce (Lactuca sativa L.) was selected as a representative green-grown crop. Each of the soil samples was treated with a slow release fertilizer, simulating the real fertilizing strategy of the tillage. In order to estimate the potential risk for aquifers as well as for organisms exposed via pore water, nitrate concentrations in groundwater were evaluated by applying a simplified attenuation model to the experimental data. Results were refined and extended from comparison of single effects and exposure values (Tier I level) up to the evaluation of probabilistic distributions of exposure and related effects (Tier II, III IV levels). HHRA suggested HI >1 and about 20% probability of exceeding RfD for all the greenhouses, regardless of the soil. ERA suggested HQ>100 for all the greenhouses; 93% probability of PNEC exceedance for greenhouses containing sand clay loam. The probability of exceeding LC50 for 5% of the species was about 40% and the probability corresponding to DBQ of DEC/EC50>0.001 was >90% for all the greenhouses. The significantly high risk, related to the detected nitrate leaching loss, can be attributed to excessive and inappropriate fertigation strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Characterizing groundwater/surface-water interactions in the interior of Jianghan Plain, central China

    Science.gov (United States)

    Du, Yao; Ma, Teng; Deng, Yamin; Shen, Shuai; Lu, Zongjie

    2018-01-01

    Quantifying groundwater/surface-water interactions is essential for managing water resources and revealing contaminant fate. There has been little concern on the exchange between streams and aquifers through an extensive aquitard thus far. In this study, hydrogeologic calculation and tritium modeling were jointly applied to characterize such interactions through an extensive aquitard in the interior of Jianghan Plain, an alluvial plain of Yangtze River, China. One groundwater simulation suggested that the lateral distance of influence from the river was about 1,000 m; vertical flow in the aquitard followed by lateral flow in the aquifer contributed significantly more ( 90%) to the aquifer head change near the river than lateral bank storage in the aquitard followed by infiltration. The hydrogeologic calculation produced vertical fluxes of the order 0.01 m/day both near and farther from the river, suggesting that similar shorter-lived (half-monthly) vertical fluxes occur between the river and aquitard near the river, and between the surface end members and aquitard farther from the river. Tritium simulation based on the OTIS model produced an average groundwater residence time of about 15 years near the river and a resulting vertical flux of the order 0.001 m/day. Another tritium simulation based on a dispersion model produced a vertical flux of the order 0.0001 m/day away from the river, coupled with an average residence time of around 90 years. These results suggest an order of magnitude difference for the longer-lived (decadal) vertical fluxes between surface waters and the aquifer near and away from the river.

  3. Integrated hydrological modeling of the North China Plain and implications for sustainable water management

    Directory of Open Access Journals (Sweden)

    H. Qin

    2013-10-01

    Full Text Available Groundwater overdraft has caused fast water level decline in the North China Plain (NCP since the 1980s. Although many hydrological models have been developed for the NCP in the past few decades, most of them deal only with the groundwater component or only at local scales. In the present study, a coupled surface water–groundwater model using the MIKE SHE code has been developed for the entire alluvial plain of the NCP. All the major processes in the land phase of the hydrological cycle are considered in the integrated modeling approach. The most important parameters of the model are first identified by a sensitivity analysis process and then calibrated for the period 2000–2005. The calibrated model is validated for the period 2006–2008 against daily observations of groundwater heads. The simulation results compare well with the observations where acceptable values of root mean square error (RMSE (most values lie below 4 m and correlation coefficient (R (0.36–0.97 are obtained. The simulated evapotranspiration (ET is then compared with the remote sensing (RS-based ET data to further validate the model simulation. The comparison result with a R2 value of 0.93 between the monthly averaged values of simulated actual evapotranspiration (AET and RS AET for the entire NCP shows a good performance of the model. The water balance results indicate that more than 70% of water leaving the flow system is attributed to the ET component, of which about 0.25% is taken from the saturated zone (SZ; about 29% comes from pumping, including irrigation pumping and non-irrigation pumping (net pumping. Sustainable water management analysis of the NCP is conducted using the simulation results obtained from the integrated model. An effective approach to improve water use efficiency in the NCP is by reducing the actual ET, e.g. by introducing water-saving technologies and changes in cropping.

  4. Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with 137Cs, 226Ra, and 238U

    Science.gov (United States)

    Chevychelov, A. P.; Sobakin, P. I.

    2017-12-01

    The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El'kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.

  5. Natural hazards on alluvial fans: the debris flow and flash flood disaster of December 1999, Vargas state, Venezuela

    Science.gov (United States)

    Larsen, Matthew C.; Wieczorek, Gerald F.; Eaton, L.S.; Torres-Sierra, Heriberto; Sylva, Walter F.

    2001-01-01

    Large populations live on or near alluvial fans in locations such as Los Angeles, California, Salt Lake City, Utah, Denver, Colorado, and lesser known areas such as Sarno, Italy, and Vargas, Venezuela. Debris flows and flash floods occur episodically in these alluvial fan environments, and place many communities at high risk during intense and prolonged rainfall. In December 1999, rainstorms induced thousands of landslides along the Cordillera de la Costa, Vargas, Venezuela. Rainfall accumulation of 293 mm during the first 2 weeks of December was followed by an additional 911 mm of rainfall on December 14 through 16. Debris flows and floods inundated coastal communities resulting in a catastrophic death toll of as many as 30,000 people. Flash floods and debris flows caused severe property destruction on alluvial fans at the mouths of the coastal mountain drainage network. In time scales spanning thousands of years, the alluvial fans along this Caribbean coastline are dynamic zones of high geomorphic activity. Because most of the coastal zone in Vargas consists of steep mountain fronts that rise abruptly from the Caribbean Sea, the alluvial fans provide practically the only flat areas upon which to build. Rebuilding and reoccupation of these areas requires careful determination of hazard zones to avoid future loss of life and property. KEY TERMS: Debris flows, flash floods, alluvial fans, natural hazards, landslides, Venezuela

  6. Hydrology, vegetation, and soils of four north Florida River flood plains with an evaluation of state and federal wetland determinations

    Science.gov (United States)

    Light, H.M.; Darst, M.R.; MacLaughlin, M.T.; Sprecher, S.W.

    1993-01-01

    A study of hydrologic conditions, vegetation, and soils was made in wetland forests of four north Florida streams from 1987 to 1990. The study was conducted by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Regulation to support State and Federal efforts to improve wetland delineation methodology in flood plains. Plant communities and soils were described and related to topographic position and long-term hydrologic conditions at 10 study plots located on 4 streams. Detailed appendixes give average duration, frequency, and depth of flooding; canopy, subcanopy, and ground-cover vegetation; and taxonomic classification, series, and profile descriptions of soils for each plot. Topographic relief, range in stage, and depth of flooding were greatest on the alluvial flood plain of the Ochlockonee River, the largest of the four streams. Soils were silty in the lower elevations of the flood plain, and tree communities were distinctly different in each topographic zone. The Aucilla River flood plain was dominated by levees and terraces with very few depressions or low backwater areas. Oaks dominated the canopy of both lower and upper terraces of the Aucilla flood plain. Telogia Creek is a blackwater stream that is a major tributary of the Ochlockonee River. Its low, wet flood plain was dominated by Wyssa ogeche (Ogeechee tupelo) trees, had soils with mucky horizons, and was inundated by frequent floods of very short duration. The St. Marks River, a spring-fed stream with high base flow, had the least topographic relief and lowest range in stage of the four streams. St. Marks soils had a higher clay content than the other streams, and limestone bedrock was relatively close to the surface. Wetland determinations of the study plots based on State and Federal regulatory criteria were evaluated. Most State and Federal wetland determinations are based primarily on vegetation and soil characteristics because hydrologic records are usually not

  7. Petrophysical characteristics of basalt in the vadose zone, Idaho National Engineering Laboratory, Eastern Snake River Plain, Idaho

    International Nuclear Information System (INIS)

    Knutson, C.F.; Harrison, W.E.; Smith, R.P.

    1989-01-01

    We have used a core characterization system to measure bulk densities, porosities, and permeabilities of basalt lavas from the vadose zone at the Idaho National Engineering Laboratory (INEL). At the INEL, basalt lava flows with intercalated alluvial, aeolian, and lacustrine sediments extend to depths of one kilometer or more. Individual lava flows are generally less than 15 meters thick and commonly have vesicular tops and bottoms with massive basalt in their interiors. Petrophysical characterization is essential to an understanding of fluid movement in the vadose zone and in the saturated zone. Many hundreds of closely spaced permeability/porosity/bulk density measurements have defined the variability of these parameters within and between individual basalt flows. Based on geological logging and porosity/permeability measurements made on many hundred feet of core, we feel that a rather sophisticated and rigorous logging program is necessary to characterize these complex and highly variable basaltic flow units. This paper endeavors to provide a petrophysical/geological conceptual model of the Snake River Plain basalts from the vadose zone under the Radioactive Waste Management Complex area at the INEL. We hope that this model will aid in subsequent geotechnical logging in this portion of the Eastern Snake River Plain. 8 refs., 14 figs., 2 tabs

  8. Impacts of water erosion on soil physical properties of an Oxisol and an Inceptisol in the Eastern Plains of Colombia

    International Nuclear Information System (INIS)

    Obando, Franco H

    1999-01-01

    On the basis of soil losses records during 10 years, three levels of water erosion were established for two soil (Typical Hapludox and Oxic Dystropept) located on high and medium terraces of alluvial flat plain of piedmont in the Eastern Plains in La Libertad Research Center of CORPOICA. Eighteen 3 x 10 m 2 run-off plots were fitted out on a nonrandom arrangement of nine plots by landscape and three soil use and management treatments: zero grazing Brachiaria decumbens pasture for six years, up land rice, soybean and maize rotations for six years and bare soil for 10 years. Soil losses under these treatments allowed to define three degrees of erosion: slight (N 3 moderate (N 2 ) and severe (N 3 ) respectively. From each plot soil samples were taken at two depths for physical analyses. infiltration and resistance to cone penetration were measured in the field. Without exception water erosion produced a detrimental effect on soil physical properties and the hydrological function of both experimental soils. Water retention capacity for N 2 and N 3 erosion levels did not present significant differences. Weighed mean diameter, DPM, of water stable aggregates was significantly greater on in the slightly (N 1 ) erosion level. Bulk density presented values significantly higher at 0-1 cm depth on both a soils

  9. Defining 'plain language' in contemporary South Africa

    African Journals Online (AJOL)

    Kate H

    dimensions that are “characteristically human [and take the form of] the logical, the historical, ... the philosopher Cicero (James 2008: 3), are still important in plain language work: invention ... databases, help files, content management systems, etc., that essentially serve the same ...... From a talent to a scientific discipline.

  10. Porosity Prediction of Plain Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Muhammad Owais Raza Siddiqui

    2014-12-01

    Full Text Available Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric, which are related to the porosity of fabric. In this work, a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D solid and multifilament weft knitted fabric models and accurately determine the porosity of fabrics in two steps. In this work, plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In the case of staple fiber yarn, intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric and the second step is to calculate the porosity of the fabric by using the geometrical parameter of 3D weft knitted fabric model generated in step one. The predicted porosity of plain weft knitted fabric is extracted in the second step and is displayed in the message area. The predicted results obtained from the plug-in have been compared with the experimental results obtained from previously developed models; they agreed well.

  11. Necrotizing fasciitis : plain radiographic and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Dae; Park, Jeong Hee; Jeon, Hae Jeong; Lim, Jong Nam; Heo, Tae Haeng; Park, Dong Rib [Konkuk Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To evaluate the plain radiographic and CT findings of the necrotizing fasciitis. We retrospectively reviewed the radiologic findings of 4 cases with necrotizing fasciitis. Three cases were proven pathologically. We evaluated pattern and extent of the gas shadows in plain films. CT findings were analysed, with emphasis on : (a) gas pattern, (b) extent, (c) location and involved site, (d) associated focal abscess, and (e) swelling of the adjacent muscles. On plain radiographs, four cases showed streaky or mottled gas densities in the pelvis, three cases in the perineum, one case in the abdomen, and two cases in the thigh. On CT images, gas pattern was mottled and streaky appearance with swelling of the adjacent muscles. Gas shadows located in the extraperitoneal space in four cases, fascial layer in four cases, and subcutaneous layer in four cases. There were gas shadows in pelvic wall, perineum, abdominal wall, buttock, thigh, and scrotum. Focal low density lesion suggestive of focal abscess was not visualized. Plain radiography is useful for early diagnosis of the necrotizing fasciitis and CT is very useful for detection of precise location and extent of the disease. CT is also useful for differentiation of necrotizing fasciitis from focal abscess and cellulitis.

  12. Cardiac Arrest Following Spinal Anaesthesia With Plain ...

    African Journals Online (AJOL)

    year old woman who was admitted for an elective caesarean section. After preoperative evaluation and premedication she received a spinal anaesthesia in the L3-4 interspace with plain bupivacaine 0.5%. After being replaced in the supine ...

  13. Radiocesium in wheat of the Po plain

    International Nuclear Information System (INIS)

    Dominici, G.; Malvicini, A.

    1988-01-01

    The Cs-137 measurements of many wheat samples, which was cultivated in Po plain during 1986 and 1987, are reported. A relationship is also shown between the quantity of Cs-137, which is contained in total fall-out, and that in the wheat by direct deposition

  14. Second chance for the plains bison

    Science.gov (United States)

    Freese, Curtis H.; Aune, K.; Boyd, D.; Derr, James N.; Forrest, Steven C.; Gates, C. Cormack; Gogan, Peter J.; Grassel, Shaun M.; Halbert, Natalie D.; Kunkel, Kyran; Redford, Kent

    2007-01-01

    Before European settlement the plains bison (Bison bison bison) numbered in the tens of millions across most of the temperate region of North America. Within the span of a few decades during the mid- to late-1800s its numbers were reduced by hunting and other factors to a few hundred. The plight of the plains bison led to one of the first major movements in North America to save an endangered species. A few individuals and the American Bison Society rescued the remaining animals. Attempts to hybridize cattle and bison when bison numbers were low resulted in extensive cattle gene introgression in bison. Today, though approximately 500,000 plains bison exist in North America, few are free of cattle gene introgression, 96% are subject to anthropogenic selection for commodity production, and only 4% are in herds managed primarily for conservation purposes. Small herd size, artificial selection, cattle-gene introgression, and other factors threaten the diversity and integrity of the bison genome. In addition, the bison is for all practical purposes ecologically extinct across its former range, with multiple consequences for grassland biodiversity. Urgent measures are needed to conserve the wild bison genome and to restore the ecological role of bison in grassland ecosystems. Socioeconomic trends in the Great Plains, combined with new information about bison conservation needs and new conservation initiatives by both the public and public sectors, have set the stage for significant progress in bison conservation over the next few years.

  15. Great plains regional climate assessment technical report

    Science.gov (United States)

    The Great Plains region (GP) plays important role in providing food and energy to the economy of the United States. Multiple climatic and non-climatic stressors put multiple sectors, livelihoods and communities at risk, including agriculture, water, ecosystems and rural and tribal communities. The G...

  16. Preliminary report on arsenic and heavy metals contents in soils and stream bed sediments of Cornia, Bruna and Alma coastal plains (Southern Tuscany

    Directory of Open Access Journals (Sweden)

    Dughetti F.

    2013-04-01

    Full Text Available The Department of Earth Sciences of University of Florence has conducted over the past ten years, numerous studies about the distribution of arsenic and heavy metals in mineralized areas of Tuscany, particularly in the Pecora basin. The area hosts several polymetallic ore bodies and a pyrite ore deposit. The studies have identified several geochemical anomalies (As, Cu, Pb, Zn… both in the areas which host the ore bodies and in the coastal plain (Scarlino Plain. To increase the knowledge concerning the distribution of As and heavy metals in other Tuscan coastal plains, research is under way in the alluvial plains of the Bruna, Cornia and Alma rivers. The preliminary analysis have focused on soils and stream sediments, to better understand the correlations between the downstream transport of rivers and the soils. We have made physic-chemical analysis, particle size analysis, mineralogical analysis for X-ray powder diffraction, chemical analysis for the determination of major element (X-ray Fluorescence and for the determination of 35 minor elements and traces (AAS and ICP.Preliminary data show high concentrations of several elements (As, Zn, Co…. The concentrations of these elements in soils and stream bed sediments are not always consistent; in particular we have found higher concentrations in soils than in stream bed sediments in Cornia Plain, while the opposite happens in the Bruna basin. Therefore the natural processes of rocks weathering does not seem to have affected uniformly. The distribution of As and heavy metals in soils and stream bed sediments of the all three basins of interest are still under investigation.

  17. 49 CFR 230.102 - Tender plain bearing journal boxes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing...

  18. 7 CFR 650.25 - Flood-plain management.

    Science.gov (United States)

    2010-01-01

    ... user how alternative land use decisions may affect the aquatic and terrestial ecosystems, human safety... Flood-plain management. Through proper planning, flood plains can be managed to reduce the threat to... encourages sound flood-plain management decisions by land users. (a) Policy—(1) General. NRCS provides...

  19. 49 CFR 215.111 - Defective plain bearing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing. 215.111 Section 215.111... § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has a plain bearing— (a) That is missing, cracked, or broken; (b) On which the bearing liner— (1) Is...

  20. 49 CFR 215.113 - Defective plain bearing wedge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing wedge. 215.113 Section 215... Suspension System § 215.113 Defective plain bearing wedge. A railroad may not place or continue in service a car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  1. Plains Energy Services Ltd. 1998 annual report

    International Nuclear Information System (INIS)

    1999-01-01

    Plains Energy Services Ltd. (Plains) is a two year old public company in the oil and gas service industry. It provides an integrated pool of services, concentrating on the life cycle of oil and gas wells as the driver for its expansion. Although the industry saw a marked decrease in well drilling activity for 1998, Plains was able to sustain a consistent income and cash flow because of its focus on ensuring access to the well during drilling, completion, production and abandonment. For 1998, revenue reached a record $93.3 million, an 85 per cent increase over 1997. This report presented Plain's major achievements for 1998. These included the completed construction of a technical, machining and manufacturing facility to enhance the development and implementation of technology and equipment among all business units. The company also introduced coiled tubing drilling services in the North American marketplace, as well as the first commercial version of a casing inspection tool. Plain's also introduced production logging through their wireline services business and applied for four new patents in relation to downhole tool development. In 1998, the company consolidated their operations into four divisions including consolidation of administration, benefits, banking and related overhead services. This report also described the company's efforts in addressing the year 2000 challenge. The company's consolidated financial statements were presented for the benefit of shareholders. These included statements of earnings and deficit, balance sheets, as well as statements of changes in financial position. Notes to the consolidated financial statements included highlights of significant accounting policies, changes in accounting policies, acquisitions, discontinued operations, and capital assets. tabs., figs

  2. Potential impacts of damming the Juba Valley, western Somalia: Insights from geomorphology and alluvial history

    Science.gov (United States)

    Williams, Martin

    2014-05-01

    In 1988 plans were well advanced to dam the Juba River in western Somalia. The aims of the Baardheere Dam Project were to generate hydroelectric power for the capital Mogadishu, and to provide water for irrigation in the Juba Valley. A reconnaissance survey on foot along 500 km of the river upstream of the proposed dam site at Baardheere and detailed geomorphic mapping from air photos provided a basis for reconstructing the late Quaternary alluvial history of the river and for assessing the potential impact of the proposed dam. The Juba River rises in the Ethiopian Highlands and is the only river in Somalia that flows to the sea. Its history reflects climatic events in Ethiopia, where the Rift Valley lakes were very low during the LGM (21±2 ka), and high for about 5, 000 years before and after then. Cave deposits in Somalia indicate wetter conditions at 13, 10, 7.5 and 1.5 ka. Alluvial terraces in the Juba Valley range in age from late Pleistocene to late Holocene but only attain a few metres above the present floodplain. This is because the dry tributary valleys contain limestone caves and fissures that divert any high flows from the parent river underground, a process not known when the project was first approved. The oldest preserved terrace was cemented by calcrete by 40 ka. Alluvial gravels were deposited at the outlet of dry tributary valleys during times of episodic high-energy flow between 26 ka and 28 ka. Finely laminated shelly sands accumulated at 10 ka to form the 5 m terrace. The 2 m terrace was laid down 3.2 ka ago as a slackwater deposit. The lack of high-level alluvial terraces raises doubts over plans to dam the river, since rapid leakage would occur from side valleys and the reservoir would not attain the height needed to generate hydroelectric power. It would submerge all existing arable land along the river. Finally, the presence in the late Holocene alluvium of the sub-fossil gastropods Bulinus truncatus and Biomphalaria pfeifferi, which are

  3. Age and origin of the Gezira alluvial fan between the Blue and White Nile rivers

    Science.gov (United States)

    Williams, martin

    2014-05-01

    The Gezira is a low-angle alluvial fan bounded by the Blue Nile to the east and the White Nile to the west. It is the main agricultural region of Sudan and produces high quality long-staple cotton for export. Dark cracking clays (vertisols) cover much of the Gezira and range in age from 50 kyr to Holocene. The Gezira is traversed by a series of defunct sandy channels that originate between Sennar and Wad Medani on the present-day Blue Nile. With a radius of 300 km and an area of 40,000 km2 the Gezira is a mega-fan. The younger channels range in age from early Holocene to 100 kyr, while near surface channels filled with rolled quartz and carbonate gravels have ages back to >250 kyr. Boreholes in the Gezira reveal coarse alluvial sands and gravels in now buried channels overlain by alluvial clays, forming a repetitive sequence of fining-upwards alluvial units. that probably extend back to Pliocene times. The fan is up to 180 m thick with a volume of ~1,800 km3. The sandy or gravelly bed-load channels coincide with colder drier climates and sparse vegetation in the Ethiopian headwaters of the Blue Nile and the alluvial clays denote widespread flooding during times of stronger summer monsoon. The early stages of such flood events were often accompanied by mass burial of Nile oyster (Etheria elliptica) beds, such as the 45-50 kyr floods that deposited up to 5 m of clay in the northern Gezira. A unique feature of the eastern Gezira is a former Blue Nile channel at least 80 km long running parallel to the present river and entirely filled with volcanic ash. The channel was only 3-4 m deep and 20-30 m wide. Very fine laminations and cross-beds, together with locally abundant phytoliths and sponge spicules, suggest slow-moving water, with flow dispersed across many distributary channels. The ash geochemistry is similar to that in the lower part of the Kibish Formation in the lower Omo valley of southern Ethiopia and points to a minimum age of 100 kyr and a maximum age of

  4. Controls on sediment cover in bedrock-alluvial channels of the Henry Mountains, Utah

    Science.gov (United States)

    Hodge, R. A.; Yager, E.; Johnson, J. P.; Tranmer, A.

    2017-12-01

    The location and extent of sediment cover in bedrock-alluvial channels influences sediment transport rates, channel incision and instream ecology. However, factors affecting sediment cover and how it responds to changes in relative sediment supply have rarely been quantitatively evaluated in field settings. Using field surveys and SFM analysis of channel reach topography, we quantified sediment cover and channel properties including slope, width, grain size distributions, and bedrock and alluvial roughness in North Wash and Chelada Creek in the Henry Mountains, Utah. Along reaches where upstream sediment supply does not appear to be restricted, we find that the fraction of local bedrock exposure increases as a function of local relative transport capacity . In a downstream section of Chelada Creek, decadal-scale sediment supply has been restricted by an upstream culvert that has caused a backwater effect and corresponding upstream deposition. In this section, alluvial cover is uncorrelated with local stream power. To test the impact of relative sediment supply on sediment cover, a 1D sediment transport model was used to predict the equilibrium sediment cover in Chelada Creek under varying flow and sediment supply conditions. Sediment transport in each model section was predicted using the partial cover model of Johnson (2015), which accounts for differences in bedrock and alluvial roughness on critical shear stress and flow resistance. Model runs in which sediment supply was approximately equal to mean transport capacity produced a pattern of sediment cover which best matched the field observations upstream of the culvert. However, runs where sediment supply was under-capacity produced the pattern most similar to field observations downstream of the culvert, consistent with our field-based interpretations. Model results were insensitive to initial sediment cover, and equilibrium was relatively quickly reached, suggesting that the channel is responsive to changes in

  5. Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Keene, Joshua L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating to the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.

  6. Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California

    Science.gov (United States)

    Machette, Michael N.; Slate, Janet L.; Phillips, Fred M.

    2008-01-01

    We have used terrestrial cosmogenic nuclides (TCN) to establish the age of some of the most extensive Quaternary alluvial fans in Death Valley, California. These intermediate-age alluvial fans are most extensive on the western side of the valley, where tectonic deformation is considerably less pronounced than on the eastern side of the valley. These fans are characterized by a relatively smooth, densely packed desert pavement formed by well-varnished (blackened) clasts. These surfaces have been mapped as the Q2 gravel by previous workers and as unit Qai (intermediate age) by us. However, the intermediate-age gravels probably contain multiple subunits, as evidenced by slight differences in morphologic expression, soil formation, and inset geomorphic relations. The TCN technique used herein sums the cosmogenic 36Cl in approximately 2.5-meter-deep profiles through soil and host alluvium, thus avoiding some of the problems associated with the more typical surface-exposure dating of boulders or smaller clasts. Our TCN 36Cl dating of 12 depth profiles indicates that these intermediate-age (Qai) alluvial fans range from about 100 to 40 kilo-annum (ka), with a mean age of about 70 ka. An alternative interpretation is that alluvial unit Qai was deposited in two discrete episodes from 90 to 80 ka and from 60 to 50 ka, before and after MIS (marine oxygen-isotope stage) 4 (respectively). Without an intermediate-age unit, such as MIS 4 lake deposits, we can neither disprove nor prove that Qai was deposited in two discrete intervals or over a longer range of time. Thus, in Death Valley, alluvial unit Qai largely brackets MIS 4, which is not associated with a deep phase of Lake Manly. These Qai fans extend to elevations of about -46 meters (150 feet below sea level) and have not been transgressed by Lake Manly, suggesting that MIS 4 or MIS 2 lakes were rather shallow in Death Valley, perhaps because they lacked inflow from surface runoff of the Sierra Nevada drainages through

  7. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    Science.gov (United States)

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  8. Vertical and lateral variability of soils structure – potentials for environmental reconstruction. Case study of the Middle Paeleoithic alluvial plain of the Wallertheim site (Germany).

    OpenAIRE

    Becze-Deák, Judit; Langohr, Judit

    2017-01-01

    This study highlights the potential contributions of soil studies to the environmental reconstructions in terrestrial context. The soils structure of the soil-sedimentary sequence of the Middle Palaeolithic site of Wallertheim has been analysed in details. The observation of the vertical and lateral variability of the soils characteristics as well as their related distribution on large section enabled to detect the impact of various and changing climatic and environmental conditions. As such ...

  9. A Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing Wetland Functions of Forested Wetlands in Alluvial Valleys of the Coastal Plain of the Southeastern United States

    Science.gov (United States)

    2013-04-01

    galli Barnyard grass Imperata  cylindrica   Cogongrass Ligustrum japonicum   Japanese privet Ligustrum sinense   Chinese Privet Lonicera japonica... Imperata  cylindrica   Cogongrass Ligustrum japonicum   Japanese privet Ligustrum sinense   Chinese Privet Lonicera japonica   Japanese Honeysuckle...crus-galli Barnyard grass Imperata  cylindrica   Cogongrass Ligustrum japonicum   Japanese privet Ligustrum sinense   Chinese Privet Lonicera

  10. Chenier plain development: feedbacks between waves, mud and sand

    Science.gov (United States)

    Nardin, W.; Fagherazzi, S.

    2015-12-01

    Cheniers are sandy ridges parallel to the coast established by high energy waves. Here we discuss Chenier plains ontogeny through dimensional analysis and numerical results from the morphodynamic model Delft3D-SWAN. Our results show that wave energy and shelf slope play an important role in the formation of Chenier plains. In our numerical experiments waves affect Chenier plain development in three ways: by winnowing sediment from the mudflat, by eroding mud and accumulating sand over the beach during extreme wave events. We further show that different sediment characteristics and wave climates can lead to three alternative coastal landscapes: strand plains, mudflats, or the more complex Chenier plains. Low inner-shelf slopes are the most favorable for strand plain and Chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation.

  11. Genetics, medicine, and the Plain people.

    Science.gov (United States)

    Strauss, Kevin A; Puffenberger, Erik G

    2009-01-01

    The Old Order Amish and Old Order Mennonite populations of Pennsylvania are descended from Swiss Anabaptist immigrants who came to the New World in the early eighteenth century. Today they live in many small endogamous demes across North America. Genetically, these demes have dissimilar allele frequencies and disease spectra owing to unique founders. Biological and social aspects of Old Order communities make them ideal for studies in population genetics and genomic medicine, and over the last 40 years, advances in genomic science coincided with investigational studies in Plain populations. Newer molecular genetic technologies are sufficiently informative, rapid, and flexible to use in a clinical setting, and we have successfully integrated these tools into a rural pediatric practice. Our studies with the Pennsylvania Plain communities show that population-specific genetic knowledge provides a powerful framework in which to prevent disease, reduce medical costs, and create new insights into human biology.

  12. Ages of plains volcanism on Mars

    Science.gov (United States)

    Hauber, Ernst; Jagert, Felix; Broz, Petr

    2010-05-01

    Plain-style volcanism [1] is widespread in the Tharsis and Elysium volcanic provinces on Mars, [2,3]. Detailed images and topographic data reveal the morphology and topography of clusters of low shields and associated lava flows. The landforms of plains volcanism on Mars have all well-known terrestrial analogues in basaltic volcanic regions, such as Hawaii, Iceland, and in particular the Snake River Plains [4]. The very gentle flank slopes (J. (1981) Icarus, 45, 586-601. [3] Hodges C.A. and Moore H.J. (1994) Atlas of volcanic features on Mars: USGS Prof. Paper 1534, 194 p. [4] Hauber E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 69-95. [5] Wilson L. et al. (2009) J. Volcanol. Geotherm. Res. 185, 28-46. [6] Vaucher, J. et al. (2009) Icarus 204, 418-442. [7] Baratoux D. et al. (2009) J. Volcanol. Geotherm. Res. 185, 47-68. [8] Bleacher J.E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 96-102. [9] Ivanov B.A. (2001) Space Sci. Rev. 96, 87-104. [10] Hartmann W.H. and Neukum G. (2001) Space Sci. Rev. 96, 165-194 [11] Kneissl T. et al. (2010) LPS XVI, submitted. [12] Michael, G.G. and Neukum G. (2010) Earth Planet. Sci. Lett., in press. . [13] Malin M.C. et al. (2007) JGR 112, E05S04, doi: 10.1029/2006JE002808.

  13. Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers.

    Science.gov (United States)

    Wildemeersch, S; Jamin, P; Orban, P; Hermans, T; Klepikova, M; Nguyen, F; Brouyère, S; Dassargues, A

    2014-11-15

    Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54MJ/m(3)/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for

  14. 15N Isotopic Study on Decomposition of Organic Residues Incorporated into Alluvial and Sandy Saline Soils

    International Nuclear Information System (INIS)

    El-Kholi, A. F.; Galal, Y. G. M.

    2004-01-01

    Incubation experiment was conducted to study the effect of the nitrogenous fertilizer on the decomposition and mineralization of organic residues (soybean powdered forage) as well as the release of the soil inorganic nitrogen. This technique was carried out using two types of soils, one is alluvial and the other is saline sandy soil collected from Fayoum governorate. Soybean forage has an organic carbon 23.1%, total N 1.6% and C/N ratio 14.4. Regarding the effect of incubation period on the two soil samples, the evolved NH 4 -N was generally reached its highest peak after 30-45 days, in the presence of either the added 15 No3-fertilizer solely or in combination with soybean forage. Reversible trend was occurred with regard to the evolved No3-N. The highest peak of evolved No3-N recorded in unfertilized control, as compared to 15 No3-N treatment, at 30 day incubation period indicated that the addition of labeled mineral fertilizer had appreciably enhanced the immobilization process. Net nitrification revealed that it was the highest in unfertilized control soil where it was significantly decreased in the treated two soil samples. Gross mineralization as affected by the addition of soybean forage in combination with labeled mineral fertilizer had been promoted by 75% in the alluvial soil and by 18% in the sandy saline soil, as compared with the soil samples received 15 No3-fertilizer only. Gross immobilization, in soil samples received 15 No3-fertilizer plus soybean forage had surpassed those received 15 No3-fertilizer only by 16% in the alluvial soil and by 25% in the sandy saline soil. (Authors)

  15. Heavy Metals Pollution of Alluvial Soil in the Copşa Mică Area

    OpenAIRE

    , D. Popa; , I.M. Prundeanu; , R. Lăcătuşu

    2011-01-01

    The objective of our study was to determine the concentrations of heavy metals (Cd, Cr, Co, Cu, Mn, Ni, Pb, Zn and Fe) from soil samples, which have been previously treated with HNO3 and concentrated HClO4. The study was performed on a series of 24 soil samples and one soil profile, collected from the alluvial soil in the Copşa Mică area. The concentrations of heavy metals were determined using Atomic Absorption Spectrometry. The pH was determined by using the potentiometric method in aqueous...

  16. The application of radioactive tracers for determination of bed-load transport in alluvial rivers

    International Nuclear Information System (INIS)

    Thomsen, T.

    1980-01-01

    Radioactive isotopes have been applied for determining the transport rate of bed load in an alluvial river on the basis of: centroid velocity of the tracer particles, size and material-transporting width of mobile layer. These parameters were found by detailed measurements in the field. Computed values were produced on the basis of Engelund and Fredsoee's model on sediment transport and on the propagation of bed forms. When comparing measured and computed values, the difference was about 25%. Finally, the applicability of tracer methods for solving practical problem is discussed. (author)

  17. Distribution of plutonium and cesium in alluvial soils of the Los Alamos environs

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Miera, F.R. Jr.; Peters, R.J.

    1976-01-01

    The alluvial soils of three liquid waste disposal areas at Los Alamos were sampled to determine plutonium and cesium distributional relationships and correlations with soil physical-chemical properties. Radionuclide concentrations were determined for soil samples as a function of soil depth and distance from the waste outfall. The cesium-plutonium data were correlated with levels of organic carbon, carbonates, exchangeable and water-soluble cations, pH, cation exchange capacity, bulk density, surface area and geometric particle size of these soils. The distribution patterns of soil plutonium and cesium were also compared to the waste use history of the three study areas

  18. Optical dating using feldspar from Quaternary alluvial and colluvial sediments from SE Brazilian Plateau, Brazil

    International Nuclear Information System (INIS)

    Tatumi, Sonia H.; Peixoto, Maria Naise O.; Moura, Josilda R.S.; Mello, Claudio L.; Carmo, Isabela O.; Kowata, Emilia A.; Yee, Marcio; Brito, Silvio Luiz M.; Gozzi, Giuiliano; Kassab, Luciana R.P.

    2003-01-01

    Opticallly stimulated luminescence (OSL) dating has been applied to a wide variety of materials such as loess, sand dunes, colluvium, alluvium, volcanic products, etc., helping geologic geomorphologic studies. OSL dating results using feldspar crystals extracted from alluvial and colluvial deposits of SE Brazilian Plateau will be presented in this work. The methodology used is based on the regeneration method, with multiple aliquot protocol. A total of 23 sample ages were obtained spanning 6.5-97.2 kyr. Results of radioactive contents and comparison with radiocarbon ages will be discussed

  19. Temporal changes in the distribution of 137Cs in alluvial soils at Los Alamos

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Hakonson, T.E.; Miera, F.R. Jr.; Bostick, K.V.

    1978-05-01

    The alluvial soils of three liquid-effluent receiving areas at Los Alamos were sampled to determine 137 Cs temporal distributional relationships. Soil radionuclide concentrations were determined as a function of soil depth and distance from the waste outfall, and discussed relative to runoff transport of 137 Cs-contaminated alluvium. The inventories of soil 137 Cs in various segments of each effluent-receiving area were calculated for two sampling periods and compared with amounts of 137 Cs added to the canyons in the liquid wastes. The distribution patterns of soil cesium were compared with the waste-use history of the three study areas and the hydrologic characteristics of the canyons

  20. A participatory approach of flood vulnerability assessment in the Banat Plain, Romania

    Science.gov (United States)

    Balteanu, Dan; Costache, Andra; Sima, Mihaela; Dumitrascu, Monica; Dragota, Carmen; Grigorescu, Ines

    2014-05-01

    The Banat Plain (western Romania) is a low, alluvial plain affected by neotectonic subsidence movements, being a critical region in terms of exposure to floods. The latest extreme event was the historic floods occcured in the spring of 2005, which caused significant economic damage in several rural communities. The response to 2005 floods has highlighted a number of weaknesses in the management of hazards, such as the deficiencies of the early warning system, people awareness or the inefficiency of some mitigation measures, besides the past structural measures which are obsolete. For a better understanding of the local context of vulnerability and communities resilience to floods, the quantitative assessment of human vulnerability to floods was supplemented with a participatory research, in which there were involved five rural settlements from the Banat Plain (comprising 15 villages and a population of over 12,000 inhabitants). Thus, in the spring of 2013, a questionnaire-based survey was conducted in approx. 100 households of the affected communities and structured interviews were held with local authorities, in the framework of VULMIN project, funded by the Ministry of National Education. The questionnaire was designed based on a pilot survey conducted in 2005, several months after the flood, and was focused on two major issues: a) perception of the local context of vulnerability to environmental change and extreme events; b) perception of human vulnerability to floods (personal experience, post-disaster rehabilitation, awareness, worrying and opinion on the measures aimed to prevent and mitigate the effects of flooding). The results were correlated with a number of specific variables of the households included in the sample, such as: household structure; income source; income level; location of the dwelling in relation to floodplains. In this way, we were able to draw general conclusions about the way in which local people perceive the extreme events, such as

  1. Use of morphometric analysis and self-organizing maps for alluvial fan classification: case study on Ostorankooh altitudes, Iran

    International Nuclear Information System (INIS)

    Mokarram, Marzieh; Seif, Abdollah; Sathyamoorthy, Dinesh

    2014-01-01

    The aim of this study is to classify alluvial fans formed by high-gradient braided streams and torrents that discharge into the Oshtorankook altitudes in the Lorestan province, Iran. The morphology of the fans and their watershed is quantitatively described through estimated morphometric parameters. For relationships between geomorphological features of the fans and their drainage basins, self-organizingmaps (SOM) were used. In SOM, according to both qualitative data and morphometric variables, the clustering tendency of alluvial fans was investigated using 15 alluvial fans parameters. The results of the analysis showed that several morphologically different fan types were recognizedbased on their geomorphological characteristics in the study area. A strong positive relationship was found between the drainage basin area and size of the fan with a simple power function. In addition, the relationship between fan slope and drainage area was found to be negative and moderately strong with a simple power function

  2. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, D.A.; Laase, A.D. [Oak Ridge National Lab., TN (United States); Locke, D.A. [Oak Ridge Inst. for Science and Education, TN (United States)

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy`s Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended.

  3. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pickering, D.A.; Laase, A.D. (Oak Ridge National Lab., TN (United States)); Locke, D.A. (Oak Ridge Inst. for Science and Education, TN (United States))

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy's Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended.

  4. The preliminary study on the alluvial stratigraphy of Peinan archaeological site, Taiwan

    Science.gov (United States)

    Yang, Hsiaochin; Chen, Wenshan; Yeh, Changkeng

    2015-04-01

    Many of the activities of prehistoric people who lived in Taiwan were concentrated around river terrace environments and seldom in alluvial environments which are resulting from the rapid tectonic uplift and high erosion rate of the late Cenozoic mountain belt. However, the Peinan archaeological site, one of the most important Neolithic sites in Taiwan because of the great amount of slate slab coffins and nephrite artifacts unearthed, is located at the bottom of Peinan Hill which is formed by the activity of Lichi and Luyeh Faults. According to the radioactive carbon dating results, the Peinan alluvial fan used as cemetery was lasted over 3,700 years (5700-2000 yr BP) but the related cultural formation was only lasted 400 years (3500-3100 yr BP). What have happened to the prehistoric people? As the stratigraphic record allows archaeologists to ascertain the effects of geological processes on the preservation of the archaeological record, determining which parts of the archaeological records are absent, which have potentially been preserved, and how fragmentary are the preserved portions of the records. The limitations that geologic processes impose on the archaeological record must be recognized and understood before meaningful interpretations of prehistory can be made. Therefore, the reconstruction of the landscape and stratigraphic records in archaeological site not only provides the paleo-environmental context but also helps to explain changes that occurred to human cultures over time.

  5. Monitoring biocalcification potential of Lysinibacillus sp. isolated from alluvial soils for improved compressive strength of concrete.

    Science.gov (United States)

    Vashisht, Rajneesh; Attri, Sampan; Sharma, Deepak; Shukla, Abhilash; Goel, Gunjan

    2018-03-01

    The present study reports the potential of newly isolated calcite precipitating bacteria isolated from alluvial soil to improve the strength and durability of concrete. A total of sixteen samples of alluvial soil and sewage were collected from the different locations of province Solan (India). For isolation, enrichment culture technique was used to enrich calcite precipitating strains in Urea broth. After enrichment, fourteen distinct bacterial strains were obtained on Urea agar. Based on qualitative and quantitative screening for urease activity, five isolates were obtained possessing higher calcite formation and urease activities (38-77 μmhos/cm) as compared with standard strain of Bacillus megaterium MTCC 1684 (77 μmhos/cm). An isolate I13 identified as Lysinibacillus sp. was selected for self healing property in the concrete mix of M20. An improved compressive strength of 1.5 fold was observed in concrete samples amended with Lysinibacillus sp. over the concrete amended with B. megaterium MTCC 1684 after 28 days of curing. The higher calcite precipitation activity was indicated in Lysinibacillus sp. by FE-SEM micrographs and EDX analysis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Potential effect of natural gas wells on alluvial groundwater contamination at the Kansas City Plant

    International Nuclear Information System (INIS)

    Pickering, D.A.; Laase, A.D.; Locke, D.A.

    1993-05-01

    This report is the result of a request for further information about several abandoned natural gas wells at the US Department of Energy's Kansas City Plant (KCP). The request was prompted by an old map showing several, possibly eight, natural gas wells located under or near what is now the southeast corner of the Main Manufacturing Building at KCP. Volatile organic compound contamination in the alluvial aquifer surrounding the gas wells might possibly contaminate the bedrock aquifer if the gas wells still exist as conduits. Several circumstances exist that make it doubtful that contamination is entering the bedrock aquifers: (1) because regional groundwater flow in the bedrock beneath the KCP is expected to be vertically upward, contaminants found in the alluvial aquifer should not migrate down the old wells; (2) because of the low hydraulic conductivity of the bedrock units, contaminant transport would be extremely slow if the contaminants were migrating down the wells; and (3) casing, apparently set through the alluvium in all of the wells, would have deteriorated and may have collapsed; if the casing collapsed, the silty clays in the alluvium would also collapse and seal the well. No definitive information has been discovered about the exact location of the wells. No further search for or consideration of the old gas wells is recommended

  7. Fe and Mn levels regulated by agricultural activities in alluvial groundwaters underneath a flooded paddy field

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kangjoo [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of)], E-mail: kangjoo@kunsan.ac.kr; Kim, Hyun-Jung; Choi, Byoung-Young; Kim, Seok-Hwi; Park, Ki-hoon [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of); Park, Eungyu [Department of Geology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Koh, Dong-Chan [Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Yun, Seong-Taek [Department of Earth and Environmental Sciences, Korea University, Seoul 136-701 (Korea, Republic of)

    2008-01-15

    Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO{sub 4} concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO{sub 4}, supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO{sub 3} at shallow depths and by SO{sub 4} reduction at the greater depths. Isotopic and mass balance analyses revealed that NO{sub 3} and SO{sub 4} in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area.

  8. The impact of medium architecture of alluvial settings on non-Fickian transport

    Science.gov (United States)

    Zhang, Yong; Green, Christopher T.; Fogg, Graham E.

    2013-01-01

    The influence of heterogeneous architecture of alluvial aquifers on non-Fickian transport is explored using the Monte Carlo approach. More than two thousand high-resolution hydrofacies models representing seven groups of alluvial settings are built to test the effects of varying facies proportions, mean length and its anisotropy ratio, juxtapositional tendencies, and sub-facies heterogeneity. Results show that the volumetric fraction (P(Z)) of floodplain layers classified by their thicknesses Z controls the non-Fickian tailing of tracer transport at late times. A simple quantitative relationship SBTC≈SP(Z)/2-1 is built based on a multi-rate mass transfer analysis, where SBTC is the slope of the power-law portion of tracer breakthrough curve, and SP(Z) denotes the slope of the power-law portion of the distribution of P(Z) which can be measured, e.g., in core logs. At early times, the mean length of hydrofacies affects the non-Fickian tailing by controlling the channeling of flow in high-permeability non-floodplain materials and the sequestration in surrounding low-permeability floodplain layers. The competition between channeling and sequestration generates complex pre-asymptotic features, including sublinear growth of plume mean displacement, superlinear growth of plume variance, and skewed mass distribution. Those observations of the influence of medium heterogeneity on tracer transport at early and late times may lead to development of nonlocal transport models that can be parameterized using measurable aquifer characteristics.

  9. Geohydrology and water quality of the North Platte River alluvial aquifer, Garden County, Western Nebraska

    Science.gov (United States)

    Steele, Gregory V.; Cannia, James C.

    1995-01-01

    In 1993, a 3-year study was begun to describe the geohydrology and water quality of the North Platte River alluvial aquifer near Oshkosh, Garden County, Nebraska. The study's objectives are to evaluate the geohydrologic characteristics of the alluvial aquifer and to establish a network of observation wells for long-term monitoring of temporal variations and spatial distributions of nitrate and major-ion concentrations. Monitor wells were installed at 11 sites near Oshkosh. The geohydrology of the aquifer was characterized based on water-level measurements and two short-term aquifer tests. Bimonthly water samples were collected and analyzed for pH, specific conductivity, water temperature, dissolved oxygen, and nutrients that included dissolved nitrate. Concentrations of major ions were defined from analyses of semiannual water samples. Analyses of the geohydrologic and water-quality data indicate that the aquifer is vulnerable to nitrate contamination. These data also show that nitrate concentrations in ground water flowing into and out of the study area are less than the U.S. Environmental Protection Agency's Maximum Concentration Level of 10 milligrams per liter for drinking water. Ground water from Lost Creek Valley may be mixing with ground water in the North Platte River Valley, somewhat moderating nitrate concentrations near Oshkosh.

  10. Effects of silicon on photosynthetic characteristics of maize (Zea mays L.) on alluvial soil.

    Science.gov (United States)

    Xie, Zhiming; Song, Fengbin; Xu, Hongwen; Shao, Hongbo; Song, Ri

    2014-01-01

    The objectives of the study were to determine the effects of silicon on photosynthetic characteristics of maize on alluvial soil, including total chlorophyll contents, photosynthetic rate (P n), stomatal conductance (g s), transpiration rate (E), and intercellular CO2 concentration (C i ) using the method of field experiment, in which there were five levels (0, 45, 90, 150, and 225 kg · ha(-1)) of silicon supplying. The results showed that certain doses of silicon fertilizers can be used successfully in increasing the values of total chlorophyll contents, P n, and g s and decreasing the values of E and C i of maize leaves, which meant that photosynthetic efficiency of maize was significantly increased in different growth stages by proper doses of Si application on alluvial soil, and the optimal dose of Si application was 150 kg · ha(-1). Our results indicated that silicon in proper amounts can be beneficial in increasing the photosynthetic ability of maize, which would be helpful for the grain yield and growth of maize.

  11. Lower Cretaceous paleo-Vertisols and sedimentary interrelationships in stacked alluvial sequences, Utah, USA

    Science.gov (United States)

    Joeckel, R. M.; Ludvigson, G. A.; Kirkland, J. I.

    2017-11-01

    The Yellow Cat Member of the Cedar Mountain Formation in Poison Strip, Utah, USA, consists of stacked, erosionally bounded alluvial sequences dominated by massive mudstones (lithofacies Fm) with paleo-Vertisols. Sediment bodies within these sequences grade vertically and laterally into each other at pedogenic boundaries, across which color, texture, and structures (sedimentary vs. pedogenic) change. Slickensides, unfilled (sealed) cracks, carbonate-filled cracks, and deeper cracks filled with sandstone; the latter features suggest thorough desiccation during aridification. Thin sandstones (Sms) in some sequences, typically as well as laminated to massive mudstones (Flm) with which they are interbedded in some cases, are interpreted as avulsion deposits. The termini of many beds of these lithofacies curve upward, parallel to nearby pedogenic slickensides, as the features we call ;turnups.; Turnups are overlain or surrounded by paleosols, but strata sheltered underneath beds with turnups retain primary sedimentary fabrics. Turnups were produced by movement along slickensides during pedogenesis, by differential compaction alongside pre-existing gilgai microhighs, or by a combination of both. Palustrine carbonates (lithofacies C) appear only in the highest or next-highest alluvial sequences, along with a deep paleo-Vertisol that exhibits partially preserved microrelief at the base of the overlying Poison Strip Member. The attributes of the Yellow Cat Member suggest comparatively low accommodation, slow accumulation, long hiatuses in clastic sedimentation, and substantial time intervals of subaerial exposure and pedogenesis; it appears to be distinct among the members of the Cedar Mountain Formation in these respects.

  12. Fe and Mn levels regulated by agricultural activities in alluvial groundwaters underneath a flooded paddy field

    International Nuclear Information System (INIS)

    Kim, Kangjoo; Kim, Hyun-Jung; Choi, Byoung-Young; Kim, Seok-Hwi; Park, Ki-hoon; Park, Eungyu; Koh, Dong-Chan; Yun, Seong-Taek

    2008-01-01

    Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO 4 concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO 4 , supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO 3 at shallow depths and by SO 4 reduction at the greater depths. Isotopic and mass balance analyses revealed that NO 3 and SO 4 in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area

  13. Characterization of Natural Organic Matter in Alluvial Aquifer Sediments: Approaches and Implications for Reactivity

    Science.gov (United States)

    Fox, P. M.; Nico, P. S.; Hao, Z.; Gilbert, B.; Tfaily, M. M.; Devadoss, J.

    2015-12-01

    Sediment-associated natural organic matter (NOM) is an extremely complex assemblage of organic molecules with a wide range of sizes, functional groups, and structures, which is intricately associated with mineral particles. The chemical nature of NOM may control its' reactivity towards metals, minerals, enzymes, and bacteria. Organic carbon concentrations in subsurface sediments are typically much lower than in surface soils, posing a distinct challenge for characterization. In this study, we investigated NOM associated with shallow alluvial aquifer sediments in a floodplain of the Colorado River. Total organic carbon (TOC) contents in these subsurface sediments are typically around 0.1%, but can range from 0.03% up to approximately 1.5%. Even at the typical TOC values of 0.1%, the mass of sediment-associated OC is approximately 5000 times higher than the mass of dissolved OC, representing a large pool of carbon that may potentially be mobilized or degraded under changing environmental conditions. Sediment-associated OC is much older than both the depositional age of the alluvial sediments and dissolved OC in the groundwater, indicating that the vast majority of NOM was sequestered by the sediment long before it was deposited in the floodplain. We have characterized the sediment-bound NOM from two locations within the floodplain with differing physical and geochemical properties. One location has relatively low organic carbon (mineral association across different biogeochemical regimes and assess the potential reactivity of various NOM pools.

  14. The Rieti Land Reclamation Authority relevance in the management of surface waters for the irrigation purposes of the Rieti Plain (Central Italy

    Directory of Open Access Journals (Sweden)

    Lucio Martarelli

    2016-09-01

    Full Text Available The Rieti Plain is crowned by calcareous-marly reliefs (Rieti and Sabini Mountains and represents an intra-Apennine Plio- Quaternary alluvial and fluvial-lacustrine basin formed after multistage extensional tectonic processes. This territory presents huge amounts of water resources (Velino and Turano rivers; several springs; Lungo and Ripasottile lakes, relics of ancient Lacus Velinus. The aquifers occurring in the reliefs often have hydraulic continuity with the Rieti plain groundwater (detected at about 1-4 m below ground surface, which has general flow directions converging from the reliefs to the lake sector. Hydraulic exchanges between groundwater and surface waters are variable in space and time and play a relevant role for groundwater resource distribution. The Rieti Land Reclamation Authority was instituted in 1929 by Royal Decree N. 34171-3835, and integrates eight former authorities, dating the end of 1800s. It contributes to maintain the reclamation actions in the Rieti Plain, which started with the realization of the Salto and Turano artificial reservoirs, along two left tributaries of Velino River. The hydroelectric energy production purposes struggle with the reclamation and flood mitigation activities in the plain. The Land Reclamation Authority actuated the Integrated Reclamation General Project through the realization of pumping stations, connection and drainage canals, forestry-hydraulic works, rural roads, movable dams along Velino River and irrigation ditches. The irrigation activities, granted by the derivation of 5 m3/s from the Velino River, are carried out through 194,000 hectares within the territory of 42 municipalities of the Rieti Province. The Rieti Land Reclamation Authority contributes to the irrigation needs and to the environmental and hydrogeological protection and monitoring.

  15. Distal alluvial fan sediments in early Proterozoic red beds of the Wilgerivier formation, Waterberg Group, South Africa

    Science.gov (United States)

    Van Der Neut, M.; Eriksson, P. G.; Callaghan, C. C.

    The 1900 - 1700 M.a. Waterberg Group belongs to a series of southern African cratonic cover sequences of roughly equivalent age. Red beds of the Wilgerivier Formation comprise sandstones, interbedded with subordinate conglomerates and minor mudrocks. These immature sedimentary rocks exhibit lenticular bedding, radial palaeocurrent patterns and features indicative of both streamflow and gravity-flow deposition. A distal wet alluvial fan palaeoenvironmental setting is envisaged, with fan-deltas forming where alluvial lobes prograded into a lacustrine basin. Intrastratal, diagenetic alteration of ferromagnesian detrital grains and ferruginous grain coatings led to the red colouration of the Wilgerivier sediments.

  16. Hyperdensity liver tumor on plain CT

    Energy Technology Data Exchange (ETDEWEB)

    Hirota, Shozo; Hanaguri, Katsuro [Kochi Municipal Central Hospital (Japan); Shimizu, Masahumi; Sako, Masao; Harada, Yasushi

    1984-12-01

    Most liver tumors on plain CT have been recognized as low density or iso-density masses. Sometimes calcified high density masses were shown on plain CT in case of cysts or metastatic liver tumors. However, hyperdensity mass of the liver on CT, of which the density was a little higher than surrounding tissues, was very rare. Recently 7 patients with hyperdensity liver masses on plain CT were experienced: 6 hepatocellular carcinomas and 1 hepatic cavernous hemangioma. A single hyperdensity mass was shown in 4 patients, a hyperdensity mass of multiple hepatic tumors was shown in 2 patients, and some hyperdensity masses of multiple hepatic tumors were shown in 1 patient. Lesions are classified in 3 types according to the appearance of hyperdensity masses: diffuse hyperdensity all over the mass, ring like hyperdensity, creascent like hyperdensity. Intravenous contrast enhancement was performed in 2 patients: one with a primary hepatocellular carcinoma, and another with a hepatic cavernous hemangioma. In the former case the tumor margin had changed unclear, in the latter case the tumor was markedly enhanced. Our results revealed that hyperdensity liver tumors were divided into 2 types: One type, shown in a cavernous hemangioma with fatty liver, demonstrated relative hyperdensity due to lower density of the surrounding tissue. Another type, shown in 6 hepatocellular carcinomas, showed hyperdensity since the density of the tumor was hyperdensity relative to the surrounding tissue of the liver. It was suggested that the tumor with the latter type had been strongly probable of malignant one, and been recommended to receive further examination. Cause of hyperdensity was thought to be due to hemorrhage, though microcalcification could not be denyed. In Japan, no hyperdensity liver tumor had been reported partly due to a wide window width with which CT photographs were taken.

  17. Precipitation Dynamical Downscaling Over the Great Plains

    Science.gov (United States)

    Hu, Xiao-Ming; Xue, Ming; McPherson, Renee A.; Martin, Elinor; Rosendahl, Derek H.; Qiao, Lei

    2018-02-01

    Detailed, regional climate projections, particularly for precipitation, are critical for many applications. Accurate precipitation downscaling in the United States Great Plains remains a great challenge for most Regional Climate Models, particularly for warm months. Most previous dynamic downscaling simulations significantly underestimate warm-season precipitation in the region. This study aims to achieve a better precipitation downscaling in the Great Plains with the Weather Research and Forecast (WRF) model. To this end, WRF simulations with different physics schemes and nudging strategies are first conducted for a representative warm season. Results show that different cumulus schemes lead to more pronounced difference in simulated precipitation than other tested physics schemes. Simply choosing different physics schemes is not enough to alleviate the dry bias over the southern Great Plains, which is related to an anticyclonic circulation anomaly over the central and western parts of continental U.S. in the simulations. Spectral nudging emerges as an effective solution for alleviating the precipitation bias. Spectral nudging ensures that large and synoptic-scale circulations are faithfully reproduced while still allowing WRF to develop small-scale dynamics, thus effectively suppressing the large-scale circulation anomaly in the downscaling. As a result, a better precipitation downscaling is achieved. With the carefully validated configurations, WRF downscaling is conducted for 1980-2015. The downscaling captures well the spatial distribution of monthly climatology precipitation and the monthly/yearly variability, showing improvement over at least two previously published precipitation downscaling studies. With the improved precipitation downscaling, a better hydrological simulation over the trans-state Oologah watershed is also achieved.

  18. Plain film diagnosis of the liver

    International Nuclear Information System (INIS)

    Rogers, J.V. Jr.; Torres, W.E.; Clements, J.L. Jr.; Gedgaudas-McClees, R.K.

    1985-01-01

    One of the first examinations obtained routinely in abdominal radiography is the plain radiograph of the abdomen. The liver occupies anywhere from 15 to 30 percent of the area on such examinations. Thus, it is important to pay particular attention to the region of the liver and obtain as much information as possible from these films. The purpose of this chapter is to review the normal radiographic anatomy and pathology. Also, pathologic calcifications, gas collections, unusual collections of fat, and the systemic manifestations of hepatic disease are discussed within this chapter

  19. A Pleistocene coastal alluvial fan complex produced by Middle Pleistocene glacio-fluvial processes

    Science.gov (United States)

    Adamson, Kathryn; Woodward, Jamie; Hughes, Philip; Giglio, Federico; Del Bianco, Fabrizio

    2014-05-01

    A coarse-grained alluvial fan sequence at Lipci, Kotor Bay, in western Montenegro, provides a sedimentary record of meltwater streams draining from the Orjen Massif (1,894 m a.s.l.) to the coastal zone. At Lipci sedimentary evidence and U-series ages have been used alongside offshore bathymetric imagery and seismic profiles to establish the size of the fan and constrain the nature and timing of its formation. Establishing the depositional history of such coastal fans is important for our understanding of cold stage sediment flux from glaciated uplands to the offshore zone, and for exploring the impact of sea level change on fan reworking. There is evidence of at least four phases of Pleistocene glaciation on the Orjen massif, which have been U-series dated and correlated to MIS 12, MIS 6, MIS 5d-2 and the Younger Dryas. A series of meltwater channels delivered large volumes of coarse- and fine-grained limestone sediment from the glaciated uplands into the Bay of Kotor. At the southern margin of the Orjen massif, a series of large (>700 m long) alluvial fans has developed. Some of these extend offshore for up to 600 m. Lipci fan lies downstream of end moraines in the valley immediately above, which were formed by an extensive outlet glacier of the Orjen ice cap during MIS 12. The terrestrial deposits are part of the fan apex (50 m a.s.l.) that lies at the foot of a steep bedrock channel, but the majority of the fan is now more than 25 m below sea level. The terrestrial fan sediments are strongly cemented by multiple generations of calcite precipitates: the oldest U-series ages are infinite indicating that the fan is >350 ka in age. These ages are in agreement with alluvial sedimentary evidence and U-series ages from other fluvial units on Mount Orjen. The terrestrial portion of the Lipci fan surface contains several channels. These are well preserved due to cementation with calcium carbonate. Submarine imagery indicates that the now submerged portion of the fan also

  20. Temporal correlation of fluvial and alluvial sequences in the Makran Range, SE-Iran

    Science.gov (United States)

    Kober, F.; Zeilinger, G.; Ivy-Ochs, S.; Dolati, A.; Smit, J.; Burg, J.-P.; Bahroudi, A.; Kubik, P. W.; Baur, H.; Wieler, R.; Haghipour, N.

    2009-04-01

    The Makran region of southeastern Iran is an active accretionary wedge with a partially subaerial component. New investigations have revealed a rather complex geodynamic evolution of the Makran active accretionary wedge that is not yet fully understood in its entity. Ongoing convergence between the Arabian and Eurasian plates and tectonic activity since the late Mesozoic has extended all trough the Quaternary. We focus here on fluvial and alluvial sequences in tectonically separated basins that have been deposited probably in the Pliocene/Quaternary, based on stratigraphic classification in official geological maps, in order to understand the climatic and tectonic forces occurring during the ongoing accretionary wegde formation. Specifically, we investigate the influence of Quaternary climate variations (Pleistocene cold period, monsoonal variations) on erosional and depositional processes in the (semi)arid Makran as well as local and regional tectonic forces in the Coastal and Central Makran Range region. Necessary for such an analysis is a temporal calibration of alluvial and fluvial terrace sequences that will allow an inter-basin correlation. We utilize the exposure age dating method using terrestrial cosmogenic nuclides (TCN) due to the lack of otherwise datatable material in the arid Makran region. Limited radiocarbon data are only available for marine terraces (wave-cut platforms). Our preliminary 21Ne and 10Be TCN-ages of amalgamated clast samples from (un)deformed terrace and alluvial sequences range from ~250 ky to present day (modern wash). These ages agree in relative terms with sequences previously assigned by other investigations through correlation of Quaternary sequences from Central and Western Iran regions. However, our minimum ages suggest that all age sequences are of middle to late Pleistocene age, compared to Pliocene age estimates previously assigned for the oldest units. Although often suggested, a genetical relation and connection of those

  1. Landform evolution modeling of fine-grained sedimentation on alluvial fans on Mars and Earth

    Science.gov (United States)

    Morgan, A. M.; Howard, A. D.; Moore, J. M.; Swander, Z. J.; Fink, D.; Korup, O.; Hesse, P. P.; Singh, T.; Srivastava, P.

    2017-12-01

    Reconstructing how rivers respond to changes in runoff or sediment supply by incising or aggrading has been pivotal in gauging the role of the Indian Summer Monsoon (ISM) as a geomorphic driver in the Himalayas. Here we present new data on how the fluvial systems of the Lesser Himalaya of India has responded to late Quaternary climate change. Our study is based on new chronological data for fluvial aggradation and incision from the Donga alluvial fan and several reaches of the upper Alaknanda River, as well as a meta-analysis of previous work. Fluvial sediments in the Himalayas in general, and quartz from the region in particular, have been previously noted for a number of unsuitable OSL properties including large recuperation and the existence of unremovable feldspar signals, leading to controversial discussions with regard to the reliability of existing OSL chronologies in this region. In order to improve the applicability and validity of OSL in the Lesser Himalaya, we have tested and applied pulsed OSL signals (POSL) to quartz grains from alluvial terrace and fan sediments, and propose a new chronology of regional fluvial aggradation. For previously dated terraces and alluvial fan sections, our POSL ages are systematically older than previously reported OSL ages. These results suggest periods of aggradation in the Alaknanda and Dehradun Valleys mainly between 20 and 50 ka. This most likely reflects decreased stream power during periods of weakened monsoon. The concentration of in-situ cosmogenic beryllium-10 from fluvial bedrock surfaces was also used to infer bedrock surface exposure ages, which should inform about episodes of active fluvial erosion. Resulting exposure ages span between 1.3 and 9.0 ka, suggesting that strath terraces were exposed relatively recently, and incision was dominant through most of the Holocene. In combination, our results support a precipitation-driven climatic control on fluvial dynamics, which regulates the balance between stream

  2. Creep of plain weave polymer matrix composites

    Science.gov (United States)

    Gupta, Abhishek

    Polymer matrix composites are increasingly used in various industrial sectors to reduce structural weight and improve performance. Woven (also known as textile) composites are one class of polymer matrix composites with increasing market share mostly due to their lightweight, their flexibility to form into desired shape, their mechanical properties and toughness. Due to the viscoelasticity of the polymer matrix, time-dependent degradation in modulus (creep) and strength (creep rupture) are two of the major mechanical properties required by engineers to design a structure reliably when using these materials. Unfortunately, creep and creep rupture of woven composites have received little attention by the research community and thus, there is a dire need to generate additional knowledge and prediction models, given the increasing market share of woven composites in load bearing structural applications. Currently, available creep models are limited in scope and have not been validated for any loading orientation and time period beyond the experimental time window. In this thesis, an analytical creep model, namely the Modified Equivalent Laminate Model (MELM), was developed to predict tensile creep of plain weave composites for any orientation of the load with respect to the orientation of the fill and warp fibers, using creep of unidirectional composites. The ability of the model to predict creep for any orientation of the load is a "first" in this area. The model was validated using an extensive experimental involving the tensile creep of plain weave composites under varying loading orientation and service conditions. Plain weave epoxy (F263)/ carbon fiber (T300) composite, currently used in aerospace applications, was procured as fabrics from Hexcel Corporation. Creep tests were conducted under two loading conditions: on-axis loading (0°) and off-axis loading (45°). Constant load creep, in the temperature range of 80-240°C and stress range of 1-70% UTS of the

  3. Nursery stock quality as an indicator of bottomland hardwood forest restoration success in the Lower Mississippi River Alluvial Valley

    Science.gov (United States)

    Douglass F. Jacobs; Rosa C. Goodman; Emile S. Gardiner; K Frances Salifu; Ronald P. Overton; George Hernandez

    2012-01-01

    Seedling morphological quality standards are lacking for bottomland hardwood restoration plantings in the Lower Mississippi River Alluvial Valley, USA, which may contribute toward variable restoration success. We measured initial seedling morphology (shoot height, root collar diameter, number of first order lateral roots, fresh mass, and root volume), second year field...

  4. Investigation of groundwater-streamflow interactions in the Bega alluvial aquifer using tritium and stable isotope ratios

    International Nuclear Information System (INIS)

    Stone, D.J.M.; Thomas, M.; Russell, G.

    2001-01-01

    An isotope hydrology study of the Bega Valley groundwater system has been made. The investigation which focussed on environmental tritium and stable isotope ratios confirms that that the groundwater in the alluvial aquifer of the Bega Valley is sustainable at the current usage rate

  5. Distribution of technogenic radionuclides in alluvial deposits and fractions of soils in neighboring zone of Krasnoyarsk GKhK

    International Nuclear Information System (INIS)

    Linnik, V.G.; Volosov, A.G.; Korobova, E.M.; Borisov, A.P.; Potapov, V.N.; Surkov, V.V.; Borguis, A.P.; Braun, Dzh.; Alekseeva, T.A.

    2004-01-01

    Distribution of synthetic radionuclides using landscape-radiation profile of Berezovyj island. Difference in density of contamination deals with heterogeneous lithological composition of soil-forming rocks and so with different duration of flooding. Radionuclide distribution in alluvial deposits and soil fractions near Balchug village is considered, the role of thin fraction in radionuclides accumulation is determined [ru

  6. Effect of different levels of magnesium saturation on the extractability of native and applied zinc in red and alluvial soils

    International Nuclear Information System (INIS)

    Deb, D.L.; Das, S.K.; Sachdev, Pamila

    1978-01-01

    The investigation showed that Mg saturation of soil has a beneficial effect on the extractibility of native and applied zinc in soil. The soils used in the investigation were alluvial soil from Delhi and red soil from Karnataka under upland and waterlogged conditions. Zinc was applied in the form of ZnSO 4 solution labelled with 65 Zn. (M.G.B.)

  7. The Temporal-Spatial Distribution of Shule River Alluvial Fan Units in China Based on SAR Data and OSL Dating

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    2013-12-01

    Full Text Available Alluvial fans in arid and semi-arid regions can provide important evidence of geomorphic and climatic changes, which reveal the evolution of the regional tectonic activity and environment. Synthetic aperture radar (SAR remote sensing technology, which is sensitive to geomorphic features, plays an important role in quickly mapping alluvial fan units of different ages. In this paper, RADARSAT-2 (Canada’s C-band new-generation radar satellite and ALOS-PALSAR (Japan’s advanced land observing satellite, phased array type L-band SAR sensor data, acquired over the Shule River Alluvial Fan (SRAF, are used to extract backscattering coefficients, scattering mechanism-related information, and polarimetric characteristic parameters. The correlation between these SAR characteristic parameters and fan units of the SRAF of different ages was studied, and the spatial distribution of fan units, since the Late Pleistocene, was extracted based on the Maximum Likelihood classification method. The results prove that (1 some C-band SAR parameters can describe the geomorphic characteristics of alluvial fan units of different ages in the SRAF; (2 SAR data can be used to map the SRAF’s surface between the Late Pleistocene and the Holocene and to extract the spatial distribution of fan units; and (3 the time-spatial distribution of the SRAF can provide valuable information for tectonic and paleoenvironmental research of the study area.

  8. Temporal changes in the distribution of /sup 137/Cs in alluvial soils at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.W.; Hakonson, T.E.; Miera, F.R. Jr.; Bostick, K.V.

    1978-05-01

    The alluvial soils of three liquid-effluent receiving areas at Los Alamos were sampled to determine /sup 137/Cs temporal distributional relationships. Soil radionuclide concentrations were determined as a function of soil depth and distance from the waste outfall, and discussed relative to runoff transport of /sup 137/Cs-contaminated alluvium. The inventories of soil /sup 137/Cs in various segments of each effluent-receiving area were calculated for two sampling periods and compared with amounts of /sup 137/Cs added to the canyons in the liquid wastes. The distribution patterns of soil cesium were compared with the waste-use history of the three study areas and the hydrologic characteristics of the canyons.

  9. Soil mycoflora of banana and cassava in peatland and alluvial soil in Bengkulu

    Directory of Open Access Journals (Sweden)

    SUCIATMIH

    2006-10-01

    Full Text Available In order to discover the diversity and population of soil fungi, a study was carried out at banana (Musa paradisiaca and cassava (Manihot utilissima plants where both those plants planted in peatland and alluvial soil. Soil fungi were isolated using serial dilution plate method and they were incubated at both room temperature (27-28oC and 45oC. This process was replicated two times for each sample. The result indicated that from 4 soil samples, 24 genera of fungi representing 4 Ascomycotina, 15 Deuteromycotina, and 5 Zygomycotina were detected. The highest soil fungi population was found in cassava planted in peat land and incubated at room temperature (8.5 105 cfu/ g dry soil, while the lower soil fungi population came from banana plant that was planted in peat land and incubated at 45oC (7.1 103 cfu/g dry soil.

  10. Relating Hydrogeomorphic Attributes to Nutrient Uptake in Alluvial Streams of a Mountain Lake District

    Science.gov (United States)

    Arp, C. D.; Baker, M. A.

    2005-05-01

    Stream form and hydrologic processes may indirectly drive nutrient uptake, however developing predictive relationships has been elusive. Problems in establishing such relationships may lie in the sets of streams analyzed, which often span diverse channel-sizes, geology, and regions, or are too geomorphically similar. We collected field data on stream geomorphology and hydrologic and nutrient transport processes using solute injections at 22 alluvial stream reaches in the Sawtooth Mountains, Idaho, USA. Many of these streams occur near lakes, which create contrasting fluvial form and functions that we hoped would produce a broad geomorphic dataset to compare to hyporheic and dead-zone transient storage and NO3 and PO4 spiraling metrics. Preliminary results suggest that storage zone residence time (Tsto) was best predicted by sediment D50, wood abundance (CWD), and discharge (r2=0.84, pnutrient cycling processes should be further considered and investigated.

  11. Fishes in paleochannels of the Lower Mississippi River alluvial valley: A national treasure

    Science.gov (United States)

    Miranda, Leandro E.

    2016-01-01

    Fluvial geomorphology of the alluvial valley of the Lower Mississippi River reveals a fascinating history. A prominent occupant of the valley was the Ohio River, estimated to have flowed 25,000 years ago over western Tennessee and Mississippi to join the Mississippi River north of Baton Rouge, Louisiana, 750–800 km south of the present confluence. Over time, shifts in the Mississippi and Ohio rivers toward their contemporary positions have left a legacy of abandoned paleochannels supportive of unique fish assemblages. Relative to channels abandoned in the last 500 years, paleochannels exhibit harsher environmental conditions characteristic of hypereutrophic lakes and support tolerant fish assemblages. Considering their ecological, geological, and historical importance, coupled with their primordial scenery, the hundreds of paleochannels in the valley represent a national treasure. Altogether, these waterscapes are endangered by human activities and would benefit from the conservation attention afforded to our national parks and wildlife refuges.

  12. Effect of rice straw on the degradation of 14C-parathion in flooded alluvial soil

    International Nuclear Information System (INIS)

    Rajaram, K.P.; Sethunathan, N.

    1975-01-01

    Organic matter, either native or applied, influences the persistence of soil-applied pesticides. The effect of rice straw on the metabolism of parathion in an alluvial soil under flooded condition was investigated. Residues were extracted from the soil at periodic intervals after application of ethoxy 14 C-parathion to rice straw amended and unamended soil employing chloroform-diethyl ether. The radioactivity in the solvent and water fractions were estimated. The activity in the solvent phase decreased more rapidly in the rice straw amended than in unamended soil indicating enhanced degradation of parathion by rice straw amendment. The autoradiograph of thin layer chromatograms of solvent phase revealed the rapid formation of aminoparathion and an unidentified metabolite possessing P-S bond and ethoxy label in amended soil within 3 days. A polar unidentified metabolite was detected in the water phase of the unamended soil at 14 days. (author)

  13. Radiotracer technique to study movement of pollutants in an alluvial aquifer

    International Nuclear Information System (INIS)

    Kulkarni, U.P.; Sharma, Suman

    2001-01-01

    Radioisotopes are being used as tracers in many research areas. Their use in determination of groundwater flow velocity is well known. They also provide insight into the understanding the hydrological systems. In this paper, pollutant movement in an alluvial aquifer in the Ganga basin near Kanpur is evaluated using radiotracer method. Radioactive 82 Br in the form of aqueous ammonium bromide was used as a tracer to measure filtration velocity of the groundwater in the vicinity of an effluent storage lagoon of a fertilizer plant at Kanpur, U.P. Point dilution technique in a single well was applied. Filtration velocity so obtained provided relevant information about the pollutant movement in the groundwater. (author)

  14. Using oblique digital photography for alluvial sandbar monitoring and low-cost change detection

    Science.gov (United States)

    Tusso, Robert B.; Buscombe, Daniel D.; Grams, Paul E.

    2015-01-01

    The maintenance of alluvial sandbars is a longstanding management interest along the Colorado River in Grand Canyon. Resource managers are interested in both the long-term trend in sandbar condition and the short-term response to management actions, such as intentional controlled floods released from Glen Canyon Dam. Long-term monitoring is accomplished at a range of scales, by a combination of annual topographic survey at selected sites, daily collection of images from those sites using novel, autonomously operating, digital camera systems (hereafter referred to as 'remote cameras'), and quadrennial remote sensing of sandbars canyonwide. In this paper, we present results from the remote camera images for daily changes in sandbar topography.

  15. Numerical model of the lowermost Mississippi River as an alluvial-bedrock reach: preliminary results

    Science.gov (United States)

    Viparelli, E.; Nittrouer, J. A.; Mohrig, D. C.; Parker, G.

    2012-12-01

    Recent field studies reveal that the river bed of the Lower Mississippi River is characterized by a transition from alluvium (upstream) to bedrock (downstream). In particular, in the downstream 250 km of the river, fields of actively migrating bedforms alternate with deep zones where a consolidated substratum is exposed. Here we present a first version of a one-dimensional numerical model able to capture the alluvial-bedrock transition in the lowermost Mississippi River, defined herein as the 500-km reach between the Old River Control Structure and the Gulf of Mexico. The flow is assumed to be steady, and the cross-section is divided in two regions, the river channel and the floodplain. The streamwise variation of channel and floodplain geometry is described with synthetic relations derived from field observations. Flow resistance in the river channel is computed with the formulation for low-slope, large sand bed rivers due to Wright and Parker, while a Chezy-type formulation is implemented on the floodplain. Sediment is modeled in terms of bed material and wash load. Suspended load is computed with the Wright-Parker formulation. This treatment allows either uniform sediment or a mixture of different grain sizes, and accounts for stratification effects. Bedload transport rates are estimated with the relation for sediment mixtures of Ashida and Michiue. Previous work documents reasonable agreement between these load relations and field measurements. Washload is routed through the system solving the equation of mass conservation of sediment in suspension in the water column. The gradual transition from the alluvial reach to the bedrock reach is modeled in terms of a "mushy" layer of specified thickness overlying the non-erodible substrate. In the case of a fully alluvial reach, the channel bed elevation is above this mushy layer, while in the case of partial alluvial cover of the substratum, the channel bed elevation is within the mushy layer. Variations in base

  16. 49 CFR 215.107 - Defective plain bearing box: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing box: General. 215.107... Suspension System § 215.107 Defective plain bearing box: General. A railroad may not place or continue in... the bearing; or (2) Have a detrimental effect on the lubrication of the journal and the bearings. ...

  17. Analyzing the Various Approaches of Plain Language Laws.

    Science.gov (United States)

    Bowen, Betsy A., And Others

    1986-01-01

    Proposes a two-phase evaluation of the plain language laws that are designed to ensure that consumers can understand and use the personal business contracts they sign so that the best model for plain language legislation can be identified. (DF)

  18. 27 CFR 9.207 - Outer Coastal Plain.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Outer Coastal Plain. 9.207... Outer Coastal Plain. (a) Name. The name of the viticultural area described in this section is “Outer Coastal Plain”. For purposes of part 4 of this chapter, “Outer Coastal Plain” is a term of viticultural...

  19. Clinical and Plain Radiograph Pattern of Joint Dislocations and ...

    African Journals Online (AJOL)

    Plain radiograph is an integral part of early assessment of patients' evaluation, though newer imaging modalities such as magnetic resonance imaging (MRI), ... Conclusion: The shoulder joint is the most frequently dislocated and a conventional plain radiograph is still valuable as a first line investigative modality in ...

  20. 18 CFR 801.8 - Flood plain management and protection.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flood plain management and protection. 801.8 Section 801.8 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION GENERAL POLICIES § 801.8 Flood plain management and protection. (a) Periodic inundation of lands...

  1. Groundwater monitoring for remedial investigation in the Oriskany-Whitestown Sand Plain, Oneida County, New York

    International Nuclear Information System (INIS)

    Kewer, R.P.; Birckhead, E.F.

    1992-01-01

    The 50-acre Whitestown Landfill is listed by NYSDEC as a Class 2 inactive hazardous waste disposal site. During Remedial Investigations, a 23-well groundwater monitoring system was installed, exploring Wisconsin age glaciofluvial deposits of the Oriskany-Whitestown sand plain. These were described in the late 19th century as deltaic sediments deposited in a proglacial lake. However, no recent studies and only limited subsurface data were available, prompting a two-phase installation program. The landfill is located above steep bluffs 70 feet above the Mohawk River and Oriskany Creek valleys. Beneath the landfill, Phase I identified a gradational sequence of coarse to fine deltaic sediments with glacial till. This sequence was partly eroded and overlain by alluvium and colluvium in the valleys. The landfill was constructed on surficial deposits of coarse fluviodeltaic gravel. These were underlain by deltaic deposits grading from sand to silt with depth, the lower silts comprising the uppermost aquifer. The silts made identification of the water table difficult during drilling and caused problems in meeting a stringent development criterion for turbidity. Phase I found that the saturated zone, up to 50 feet thick, is perched on glaciolacustrine clays and, locally, tills, which were the lower boundary of the system investigated. Partly influenced by the clays, groundwater and contaminant movement was to the adjoining valley, causing off-site impacts in the shallow alluvial/colluvial aquifer. Therefore, Phase 11 focused on characterizing flow and groundwater quality in the discharge area, particularly with respect to an adjacent residence and wetlands. Contamination was found to extend northward only as far as the Old Erie Canal, which parallels the base of the bluff. Only limited off-site involvement was documented which will be monitored in the post-closure period using the installed well system

  2. Bacterial community structure in two permafrost wetlands on the Tibetan Plateau and Sanjiang Plain, China.

    Science.gov (United States)

    Yun, Juanli; Ju, Yiwen; Deng, Yongcui; Zhang, Hongxun

    2014-08-01

    Permafrost wetlands are important methane emission sources and fragile ecosystems sensitive to climate change. Presently, there remains a lack of knowledge regarding bacterial communities, especially methanotrophs in vast areas of permafrost on the Tibetan Plateau in Northwest China and the Sanjiang Plain (SJ) in Northeast China. In this study, 16S rRNA-based quantitative PCR (qPCR) and 454 pyrosequencing were used to identify bacterial communities in soils sampled from a littoral wetland of Lake Namco on the Tibetan Plateau (NMC) and an alluvial wetland on the SJ. Additionally, methanotroph-specific primers targeting particulate methane monooxygenase subunit A gene (pmoA) were used for qPCR and pyrosequencing analysis of methanotrophic community structure in NMC soils. qPCR analysis revealed the presence of 10(10) 16S rRNA gene copies per gram of wet soil in both wetlands, with 10(8) pmoA copies per gram of wet soil in NMC. The two permafrost wetlands showed similar bacterial community compositions, which differed from those reported in other cold environments. Proteobacteria, Actinobacteria , and Chloroflexi were the most abundant phyla in both wetlands, whereas Acidobacteria was prevalent in the acidic wetland SJ only. These four phyla constituted more than 80 % of total bacterial community diversity in permafrost wetland soils, and Methylobacter of type I methanotrophs was overwhelmingly dominant in NMC soils. This study is the first major bacterial sequencing effort of permafrost in the NMC and SJ wetlands, which provides fundamental data for further studies of microbial function in extreme ecosystems under climate change scenarios.

  3. Cosmogenic helium and volatile-rich fluid in Sierra leone alluvial diamonds

    International Nuclear Information System (INIS)

    McConville, P.; Reynolds, J.H.

    1989-01-01

    Pursuant to the discovery elsewhere of cosmogenic 10 Be in alluvial diamond fragments from Zaire, noble gas measurements were made on two identical splits of a finely powdered, harshly acid-washed sample derived from selected (for clarity) fragments of a single alluvial diamond from Sierra Leone (sample LJA → L4 and L5). Essentially identical results were obtained for both splits. Isotopic ratios for Ar, Kr, and Xe were atmospheric and their elemental abundances were high relative to published data, owing to shock implantation in the crushing as verified in a supplementary experiment. No neon was detected above blank level. 3 He was exceptionally abundant, 4 He exceptionally depleted, possibly from the acid wash, and the ratio 3 He/ 4 He almost unprecedentedly high at an R/R a value of 246 ± 16. The results support the hypothesis that excess 3 He in diamonds is cosmogenic, although a cosmic-ray exposure of 5, 35, or (impossibly) 152 Ma for cyclic gardening of the sample to a maximum depth of 0, 4.6 m, or 20 m, respectively, is required. Troublesome for the cosmogenic hypothesis is a sample from very deep in the Finsch mine, South Africa, found by Zadnik et al (1987) to have an R/R a value of 1,000. This paper includes histograms of noble gas data published prior to mid-1988 for diamonds of known provenance. The Sierra Leone diamond studied in the supplementary experiment belongs to a distinct population of 40* Ar-rich diamonds consisting mostly of cubic diamonds for Zaire

  4. Bicarbonate Impact on U(VI) Bioreduction in a Shallow Alluvial Aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Long, Philip E.; Williams, Kenneth H.; Davis, James A.; Fox, Patricia M.; Wilkins, Michael J.; Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.; Berman, Elena S.; Gupta, Manish; Chandler, Darrell P.; Murray, Christopher J.; Peacock, Aaron D.; Giloteaux, L.; Handley, Kim M.; Lovley, Derek R.; Banfield, Jillian F.

    2015-02-01

    Field-scale biostimulation and desorption tracer experiments conducted in a uranium (U) contaminated, shallow alluvial aquifer have provided insight into the coupling of microbiology, biogeochemistry, and hydrogeology that control U mobility in the subsurface. Initial experiments successfully tested the concept that Fe-reducing bacteria such as Geobacter sp. could enzymatically reduce soluble U(VI) to insoluble U(IV) during in situ electron donor amendment (Anderson et al. 2003, Williams et al. 2011). In parallel, in situ desorption tracer tests using bicarbonate amendment demonstrated rate-limited U(VI) desorption (Fox et al. 2012). These results and prior laboratory studies underscored the importance of enzymatic U(VI)-reduction and suggested the ability to combine desorption and bioreduction of U(VI). Here we report the results of a new field experiment in which bicarbonate-promoted uranium desorption and acetate amendment were combined and compared to an acetate amendment-only experiment in the same experimental plot. Results confirm that bicarbonate amendment to alluvial aquifer desorbs U(VI) and increases the abundance of Ca-uranyl-carbonato complexes. At the same time, that the rate of acetate-promoted enzymatic U(VI) reduction was greater in the presence of added bicarbonate in spite of the increased dominance of Ca-uranyl-carbonato aqueous complexes. A model-simulated peak rate of U(VI) reduction was ~3.8 times higher during acetate-bicarbonate treatment than under acetate-only conditions. Lack of consistent differences in microbial community structure between acetate-bicarbonate and acetate-only treatments suggest that a significantly higher rate of U(VI) reduction the bicarbonate-impacted sediment may be due to a higher intrinsic rate of microbial reduction induced by elevated concentrations of the bicarbonate oxyanion. The findings indicate that bicarbonate amendment may be useful in improving the engineered bioremediation of uranium in aquifers.

  5. Bicarbonate impact on U(VI) bioreduction in a shallow alluvial aquifer

    Science.gov (United States)

    Long, Philip E.; Williams, Kenneth H.; Davis, James A.; Fox, Patricia M.; Wilkins, Michael J.; Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.; Berman, Elena S. F.; Gupta, Manish; Chandler, Darrell P.; Murray, Chris; Peacock, Aaron D.; Giloteaux, Ludovic; Handley, Kim M.; Lovley, Derek R.; Banfield, Jillian F.

    2015-02-01

    Field-scale biostimulation and desorption tracer experiments conducted in a uranium (U) contaminated, shallow alluvial aquifer have provided insight into the coupling of microbiology, biogeochemistry, and hydrogeology that control U mobility in the subsurface. Initial experiments successfully tested the concept that Fe-reducing bacteria such as Geobacter sp. could enzymatically reduce soluble U(VI) to insoluble U(IV) during in situ electron donor amendment (Anderson et al., 2003; Williams et al., 2011). In parallel, in situ desorption tracer tests using bicarbonate amendment demonstrated rate-limited U(VI) desorption (Fox et al., 2012). These results and prior laboratory studies underscored the importance of enzymatic U(VI)-reduction and suggested the ability to combine desorption and bioreduction of U(VI). Here we report the results of a new field experiment in which bicarbonate-promoted uranium desorption and acetate amendment were combined and compared to an acetate amendment-only experiment in the same experimental plot. Results confirm that bicarbonate amendment to alluvial aquifer sediments desorbs U(VI) and increases the abundance of Ca-uranyl-carbonato complexes. At the same time, the rate of acetate-promoted enzymatic U(VI) reduction was greater in the presence of added bicarbonate in spite of the increased dominance of Ca-uranyl-carbonato aqueous complexes. A model-simulated peak rate of U(VI) reduction was ∼3.8 times higher during acetate-bicarbonate treatment than under acetate-only conditions. Lack of consistent differences in microbial community structure between acetate-bicarbonate and acetate-only treatments suggest that a significantly higher rate of U(VI) reduction in the bicarbonate-impacted sediment may be due to a higher intrinsic rate of microbial reduction induced by elevated concentrations of the bicarbonate oxyanion. The findings indicate that bicarbonate amendment may be useful in improving the engineered bioremediation of uranium in

  6. The Importance of Bank Storage in Supplying Baseflow to Rivers Flowing Through Compartmentalized, Alluvial Aquifers

    Science.gov (United States)

    Rhodes, Kimberly A.; Proffitt, Tiffany; Rowley, Taylor; Knappett, Peter S. K.; Montiel, Daniel; Dimova, Natasha; Tebo, Daniel; Miller, Gretchen R.

    2017-12-01

    As water grows scarcer in semiarid and arid regions around the world, new tools are needed to quantify fluxes of water and chemicals between aquifers and rivers. In this study, we quantify the volumetric flux of subsurface water to a 24 km reach of the Brazos River, a lowland river that meanders through the Brazos River Alluvium Aquifer (BRAA), with 8 months of high-frequency differential gaging measurements using fixed gaging stations. Subsurface discharge sources were determined using natural tracers and End-Member Mixing Analysis (EMMA). During a 4 month river stage recession following a high stage event, subsurface discharge decreased from 50 m3/s to 0, releasing a total of 1.0 × 108 m3 of water. Subsurface discharge dried up even as the groundwater table at two locations in the BRAA located 300-500 m from the river remained ˜4 m higher than the river stage. Less than 4% of the water discharged from the subsurface during the prolonged recession period resembled the chemical fingerprint of the alluvial aquifer. Instead, the chemistry of this discharged water closely resembled high stage "event" river water. Together, these findings suggest that the river is well connected to rechargeable bank storage reservoirs but disconnected from the broader alluvial aquifer. The average width of discrete bank storage zones on each side of the river, identified with Electrical Resistivity Tomography (ERT), was approximately 1.5 km. In such highly compartmentalized aquifers, groundwater pumping is unlikely to impact the exchange between the river and the alluvium.

  7. Determinism in fish assemblages of floodplain lakes of the vastly disturbed Mississippi Alluvial Valley

    Science.gov (United States)

    Miranda, L.E.; Lucas, G.M.

    2004-01-01

    The Mississippi Alluvial Valley between southern Illinois and southern Louisiana contains hundreds of floodplain lakes, most of which have been adversely affected by landscape modifications used to control flooding and support agriculture. We examined fish assemblages in lakes of this region to determine whether deterministic patterns developed in relation to prominent abiotic lake characteristics and to explore whether relevant abiotic factors could be linked to specific assemblage structuring mechanisms. The distributions of 14 taxa in 29 lakes were governed primarily by two gradients that contrasted assemblages in terms of lake area, lake elongation, and water clarity. The knowledge of whether a lake was clear or turbid, large or small, and long or short helped determine fish assemblage characteristics. Abiotic factors influenced fish assemblage structures, plausibly through limitations on foraging and physiological tolerances. Determinism in assemblage organization of floodplain lakes relative to recurrence in physicochemical features has been documented for unaltered rivers. Whereas the Mississippi Alluvial Valley has been subjected to vast anthropogenic disturbances and is not a fully functional floodplain river, fish assemblages in its floodplain lakes remain deterministic and organized by the underlying factors that also dictate assemblages in unaltered rivers. In advanced stages of lake aging, fish assemblages in these lakes are expected to largely include species that thrive in turbid, shallow systems with few predators and low oxygen concentrations. The observed patterns related to physical characteristics of these lakes suggest three general conservation foci, including (1) watershed management to control erosion, (2) removal of sediments or increases in water level to alleviate depth reductions and derived detriments to water physicochemistry, and (3) management of fish populations through stockings, removals, and harvest regulations.

  8. Benzene dynamics and biodegradation in alluvial aquifers affected by river fluctuations.

    Science.gov (United States)

    Batlle-Aguilar, J; Morasch, B; Hunkeler, D; Brouyère, S

    2014-01-01

    The spatial distribution and temporal dynamics of a benzene plume in an alluvial aquifer strongly affected by river fluctuations was studied. Benzene concentrations, aquifer geochemistry datasets, past river morphology, and benzene degradation rates estimated in situ using stable carbon isotope enrichment were analyzed in concert with aquifer heterogeneity and river fluctuations. Geochemistry data demonstrated that benzene biodegradation was on-going under sulfate reducing conditions. Long-term monitoring of hydraulic heads and characterization of the alluvial aquifer formed the basis of a detailed modeled image of aquifer heterogeneity. Hydraulic conductivity was found to strongly correlate with benzene degradation, indicating that low hydraulic conductivity areas are capable of sustaining benzene anaerobic biodegradation provided the electron acceptor (SO4 (2-) ) does not become rate limiting. Modeling results demonstrated that the groundwater flux direction is reversed on annual basis when the river level rises up to 2 m, thereby forcing the infiltration of oxygenated surface water into the aquifer. The mobilization state of metal trace elements such as Zn, Cd, and As present in the aquifer predominantly depended on the strong potential gradient within the plume. However, infiltration of oxygenated water was found to trigger a change from strongly reducing to oxic conditions near the river, causing mobilization of previously immobile metal species and vice versa. MNA appears to be an appropriate remediation strategy in this type of dynamic environment provided that aquifer characterization and targeted monitoring of redox conditions are adequate and electron acceptors remain available until concentrations of toxic compounds reduce to acceptable levels. © 2013, National Ground Water Association.

  9. Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

    Science.gov (United States)

    Klepikova, Maria; Wildemeersch, Samuel; Hermans, Thomas; Jamin, Pierre; Orban, Philippe; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

    2016-09-01

    Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

  10. Bottomland hardwood establishment and avian colonization of reforested sites in the Mississippi Alluvial Valley

    Science.gov (United States)

    Wilson, R.R.; Twedt, D.J.; Fredrickson, L.H.; King, S.L.; Kaminski, R.M.

    2005-01-01

    Reforestation of bottomland hardwood sites in the Mississippi Alluvial Valley has markedly increased in recent years, primarily due to financial incentive programs such as the Wetland Reserve Program, Partners for Wildlife Program, and state and private conservation programs. An avian conservation plan for the Mississippi Alluvial Valley proposes returning a substantial area of cropland to forested wetlands. Understanding how birds colonize reforested sites is important to assess the effectiveness of avian conservation. We evaluated establishment of woody species and assessed bird colonization on 89 reforested sites. These reforested sites were primarily planted with heavy-seeded oaks (Quercus spp.) and pecans (Carya illinoensis). Natural invasion of light-seeded species was expected to diversify these forests for wildlife and sustainable timber harvest. Planted tree species averaged 397 + 36 stems/ha-1, whereas naturally invading trees averaged 1675 + 241 stems/ha. However, naturally invading trees were shorter than planted trees and most natural invasion occurred <100 m from an existing forested edge. Even so, planted trees were relatively slow to develop vertical structure, especially when compared with tree species planted and managed for pulpwood production. Slow development of vertical structure resulted in grassland bird species, particularly dickcissel (Spiza americana) and red-winged blackbird (Agelaius phoeniceus), being the dominant avian colonizers for the first 7 years post-planting. High priority bird species (as defined by Partners in Flight), such as prothonotary warbler (Protonotaria citrea) and wood thrush (Hylocichla mustelina), were not frequently detected until stands were 15 years old. Canonical correspondence analysis revealed tree height had the greatest influence on the bird communities colonizing reforested sites. Because colonization by forest birds is dependent on tree height, we recommend inclusion of at least one fast-growing tree

  11. ALLUVIAL DEPOSITS AS A SUBSOIL AND MATERIAL FOR BASIC HYDRO-TECHNICAL CONSTRUCTIONS

    Directory of Open Access Journals (Sweden)

    Jędrzej Wierzbicki

    2015-11-01

    Full Text Available The article presents an analysis of geotechnical parameters of the alluvial deposit (the areas of the Vistula and Warta river valleys with a view to using the soil as an earth construction material and as a foundation for buildings constructed on the grounds tested. Strength and deformation parameters of the subsoil tested were identified by the CPTU (cone penetration test and DMT (flat dilatometer test methods, as well as by the vane test (VT. The article includes the analysis of overconsolidation process of the soil tested and a formula for the identification of the overconsolidation ratio OCR. Equation 4 reflects the relation between the undrained shear strength and plasticity of the silts analyzed and the OCR value. The analysis resulted in the determination of the Nkt coefficient, which might be used to identify the undrained shear strength of both sediments tested. On the basis of a detailed analysis of changes in terms of the constrained oedometric modulus M0, the relations between the said modulus, the liquidity index and the OCR value were identified. Mayne’s formula (1995 was used to determine the M0 modulus from the CPTU test. The usefulness of the alluvial deposit as an earth construction material was analysed after their structure had been destroyed and compacted with a Proctor apparatus. In cases of samples characterized by different water content and soil particle density, the analysis of changes in terms of cohesion and the internal friction angle proved that these parameters are influenced by the soil phase composition. On the basis of the tests, it was concluded that the most desirable shear strength parameters are achieved when the silt is compacted below the optimum water content.

  12. An alluvial record of El Niño events from northern coastal Peru

    Science.gov (United States)

    Wells, Lisa E.

    1987-12-01

    Overbank flood deposits of northern coastal Peru provide the potential for the development of a late Quaternary chronology of El Niño events. Alluvial deposits from the 1982-1983 El Niño event are the basis for establishing a type El Niño deposit. Sedimentary structures suggesting depositional processes range from sheet flows to debris flows, with sheet flood deposits being the most common. The 1982-1983 deposits are characterized by a 50- to 100-cm- thick basal gravel, overlain by a 10- to 100-cm-thick sand bed, grading into a 1- to 10-cm-thick silty sand bed and capped by a very thin layer of silt or clay. The surface of the deposit commonly displays the original shear flow lines crosscut by postdepositional mud cracks and footprints (human and animal). Stacked sequences of flood deposits are present in Pleistocene and Holocene alluvial fill, suggesting that El Niño type events likely occurred throughout the late Quaternary. A relative chronology of the deposits is developed based on terrace and soil stratigraphy and on the degree of preservation of surficial features. A minimum of 15 El Niño events occurred during the Holocene; a minimum of 21 events occurred during the late Pleistocene. Timing of the Holocene events is bracketed by isochrons derived from the archaeologic stratigraphy. Corrected radiocarbon ages from included detrital wood provide the following absolute dates for El Niño events: 1720 ± 60 A.D., 1460 ± 20 A.D., 1380 ± 140 A.D. (error overlaps with the A.D. 1460 event; these may represent a single event), and 1230 ± 60 B.C.

  13. Determination of Land Use/ Land Cover Changes in Igneada Alluvial (Longos) Forest Ecosystem, Turkey

    Science.gov (United States)

    Bektas Balcik, F.

    2012-12-01

    Alluvial (Longos) forests are one of the most fragile and threatened ecosystems in the world. Typically, these types of ecosystems have high biological diversity, high productivity, and high habitat dynamism. In this study, Igneada, Kirklareli was selected as study area. The region, lies between latitudes 41° 46' N and 41° 59' N and stretches between longitudes 27° 50' E and 28° 02' E and it covers approximately 24000 (ha). Igneada Longos ecosystems include mixed forests, streams, flooded (alluvial) forests, marshes, wetlands, lakes and coastal sand dunes with different types of flora and fauna. Igneada was classified by Conservation International as one of the world's top 122 Important Plant Areas, and 185 Important Bird Areas. These types of wild forest in other parts of Turkey and in Europe have been damaged due to anthropogenic effects. Remote sensing is very effective tool to monitor these types of sensitive regions for sustainable management. In this study, 1984 and 2011 dated Landsat 5 TM data were used to determine land cover/land use change detection of the selected region by using six vegetation indices such as Tasseled Cap index of greenness (TCG), brightness (TCB), and wetness (TCW), ratios of near-infrared to red image (RVI), normalized difference vegetation index (NDVI), and soil-adjusted vegetation index (SAVI). Geometric and radiometric corrections were applied in image pre-processing step. Selective Principle Component Analysis (PCA) change detection method was applied to the selected vegetation index imagery to generate change imagery for extracting the changed features between the year of 1984 and 2011. Accuracy assessment was applied based on error matrix by calculating overall accuracy and Kappa statistics.

  14. Environment tracers application to groundwater circulation assessment in an alluvial aquifer in Central Italy

    Science.gov (United States)

    Sappa, Giuseppe; Barbieri, Maurizio; Vitale, Stefania

    2017-04-01

    Groundwater vulnerability assessment is an important tool in order to plan any groundwater protection strategy. The aim of this study is to experiment a specific approach to give a conceptual model about groundwater circulation characterization. This approach has been applied to a suspected contaminated site in a large alluvial plan, made of sediments coming from weathered volcanic rocks, laying on marine sediments, where more than thirty years ago had been built a very important urban waste solid landfill. In referring to this case history it has been pointed out the importance of natural chemical interaction between ground water and rock mass, especially when pyroclastic origin sediments are involved. The landfill had been isolated from the surrounding environment, especially to protect aquifers, by a waterproof diaphragm This land is characterised by intensive agricultural and industrial activities (oil refineries, medical waste incinerators, concrete production, tar factory). The study will highlight the importance of environmental tracers which provide information about the flow and mixing processes of water coming from different sources. They are also useful to point out directions of groundwater flow and to determine origin Environmental tracers are natural chemical and isotopic substances that can be measured in groundwater and used to understand hydrologic properties of aquifers. They may be input into the hydrological system from the atmosphere at recharge and/or are added/lost/exchanged inherently as waters flow over and through materials. Variations in their chemical abundances and isotopic compositions can be used as tracers to determine sources (provenance), pathways (of reaction or interaction) and also timescales (dating) of environmental processes. In combination with these, the basic idea is to use. In this case enviromental tracers have been integrated by temperature and electric conductivity logs, to better investigate different levels of faster

  15. Residence times and alluvial architecture of a sediment superslug in response to different flow regimes

    Science.gov (United States)

    Moody, John A.

    2017-01-01

    A superslug was deposited in a basin in the Colorado Front Range Mountains as a consequence of an extreme flood following a wildfire disturbance in 1996. The subsequent evolution of this superslug was measured by repeat topographic surveys (31 surveys from 1996 through 2014) of 18 cross sections approximately uniformly spaced over 1500 m immediately above the basin outlet. These surveys allowed the identification within the superslug of chronostratigraphic units deposited and eroded by different geomorphic processes in response to different flow regimes.Over the time period of the study, the superslug went through aggradation, incision, and stabilization phases that were controlled by a shift in geomorphic processes from generally short-duration, episodic, large-magnitude floods that deposited new chronostratigraphic units to long-duration processes that eroded units. These phases were not contemporaneous at each channel cross section, which resulted in a complex response that preserved different chronostratigraphic units at each channel cross section having, in general, two dominant types of alluvial architecture—laminar and fragmented. Age and transit-time distributions for these two alluvial architectures evolved with time since the extreme flood. Because of the complex shape of the distributions they were best modeled by two-parameter Weibull functions. The Weibull scale parameter approximated the median age of the distributions, and the Weibull shape parameter generally had a linear relation that increased with time since the extreme flood. Additional results indicated that deposition of new chronostratigraphic units can be represented by a power-law frequency distribution, and that the erosion of units decreases with depth of burial to a limiting depth. These relations can be used to model other situations with different flow regimes where vertical aggradation and incision are dominant processes, to predict the residence time of possible contaminated

  16. Residence times and alluvial architecture of a sediment superslug in response to different flow regimes

    Science.gov (United States)

    Moody, John A.

    2017-10-01

    A superslug was deposited in a basin in the Colorado Front Range Mountains as a consequence of an extreme flood following a wildfire disturbance in 1996. The subsequent evolution of this superslug was measured by repeat topographic surveys (31 surveys from 1996 through 2014) of 18 cross sections approximately uniformly spaced over 1500 m immediately above the basin outlet. These surveys allowed the identification within the superslug of chronostratigraphic units deposited and eroded by different geomorphic processes in response to different flow regimes. Over the time period of the study, the superslug went through aggradation, incision, and stabilization phases that were controlled by a shift in geomorphic processes from generally short-duration, episodic, large-magnitude floods that deposited new chronostratigraphic units to long-duration processes that eroded units. These phases were not contemporaneous at each channel cross section, which resulted in a complex response that preserved different chronostratigraphic units at each channel cross section having, in general, two dominant types of alluvial architecture-laminar and fragmented. Age and transit-time distributions for these two alluvial architectures evolved with time since the extreme flood. Because of the complex shape of the distributions they were best modeled by two-parameter Weibull functions. The Weibull scale parameter approximated the median age of the distributions, and the Weibull shape parameter generally had a linear relation that increased with time since the extreme flood. Additional results indicated that deposition of new chronostratigraphic units can be represented by a power-law frequency distribution, and that the erosion of units decreases with depth of burial to a limiting depth. These relations can be used to model other situations with different flow regimes where vertical aggradation and incision are dominant processes, to predict the residence time of possible contaminated

  17. Multi-approach assessment of the spatial distribution of the specific yield: application to the Crau plain aquifer, France

    Science.gov (United States)

    Seraphin, Pierre; Gonçalvès, Julio; Vallet-Coulomb, Christine; Champollion, Cédric

    2018-03-01

    Spatially distributed values of the specific yield, a fundamental parameter for transient groundwater mass balance calculations, were obtained by means of three independent methods for the Crau plain, France. In contrast to its traditional use to assess recharge based on a given specific yield, the water-table fluctuation (WTF) method, applied using major recharging events, gave a first set of reference values. Then, large infiltration processes recorded by monitored boreholes and caused by major precipitation events were interpreted in terms of specific yield by means of a one-dimensional vertical numerical model solving Richards' equations within the unsaturated zone. Finally, two gravity field campaigns, at low and high piezometric levels, were carried out to assess the groundwater mass variation and thus alternative specific yield values. The range obtained by the WTF method for this aquifer made of alluvial detrital material was 2.9- 26%, in line with the scarce data available so far. The average spatial value of specific yield by the WTF method (9.1%) is consistent with the aquifer scale value from the hydro-gravimetric approach. In this investigation, an estimate of the hitherto unknown spatial distribution of the specific yield over the Crau plain was obtained using the most reliable method (the WTF method). A groundwater mass balance calculation over the domain using this distribution yielded similar results to an independent quantification based on a stable isotope-mixing model. This agreement reinforces the relevance of such estimates, which can be used to build a more accurate transient hydrogeological model.

  18. Myxomatosis on the Western Plains of Victoria.

    Science.gov (United States)

    Tighe, F G; Edmonds, J W; Nolan, I F; Shepherd, R C; Gocs, A

    1977-10-01

    Myxomatosis on the Western Plains is an enzootic disease in contrast with the epizootic pattern which is general in eastern Australia. The most unusual aspects are the presence of significant numbers of diseased rabbits throughout the winter and the continuously low percentage of rabbits with antibodies to myxoma virus. Climatic and topographic conditions are unsuited to the production of the high densities of mosquitoes necessary for widespread epizootics. Under these conditions the effects of less efficient methods of myxomatosis transmission are apparent. The unusual epidemiology of myxomatosis has resulted in selection for virulence of the virus similar to that which has occurred under summer epizootic conditions. All field strains are now in the mid range of virulence.

  19. Assessment of intrinsic vulnerability of an alluvial aquifer under anthropogenic pressure: cross comparison of 4 index-based groundwater vulnerability mapping models within the Biguglia lagoon watershed (Corsica, France).

    Science.gov (United States)

    Jaunat, Jessy; Huneau, Frédéric; Garel, Emilie; Devos, Alain; Lejeune, Olivier

    2016-04-01

    KEYWORDS: Alluvial aquifer, Vulnerability mapping, Index-based methods, DRASTIC, SINTACS, SI, GOD The geographical position of the Biguglia lagoon watershed south of the Bastia city (80 000 inhabitants), lead to a highly vulnerable hydrosystem setting. This littoral plain is the unique territory available for the urbanisation and for the agriculture activities (cattle breeding). All the activities developed are likely to have a qualitative impact on water infiltration and therefore on groundwater, which is in hydraulic connection with the lagoon system. Beyond this ecological issue, groundwater of this watershed is intensively used as drinking water supply. It appears essential to control the long-term groundwater quality of the Biguglia plain which is the major economic zone of Corsica. Achievement of this issue requires the identification of the areas where the alluvial aquifer is mostly vulnerable to anthropogenic activities. The results given by 4 of the most popular index-based vulnerability mapping methods (DRASTIC, SI, SINTACS and GOD) are compared. The water table, net recharge, aquifer and soils properties, topography, vadose zone and land uses have been precisely mapped and numerically translated in GIS with a 25m precision. 4 final maps were finally compiled according to the weighting factors of each methods. Hydrochemical investigations were also carried out on 30 sampling points (major ions and anthropogenic tracers) to evaluate the effect of anthropogenic activities on groundwater quality and also to validate the results of the vulnerability mapping. A comparison between the parametric models shows a significant agreement between the DRASTIC, SINTACS and SI results (2% to 5% of the total area in very low vulnerability class, 10% to 13% in low vulnerability, 16% to 23% in medium vulnerability, 31% to 53% in high vulnerability and 14% to 23% in very high vulnerability). The two first methods are quite similar, which explains the proximity of the

  20. Two depositional models for Pliocene coastal plain fluvial systems, Goliad Formation, south Texas Gulf Coastal plain

    International Nuclear Information System (INIS)

    Hoel, H.D.; Galloway, W.E.

    1983-01-01

    The Goliad Formation consists of four depositional systems-the Realitos and Mathis bed-load fluvial systems in the southwest and the Cuero and Eagle Lake mixed-load fluvial systems in the northeast. Five facies are recognized in the Realitos and Mathis bed-load fluvial systems: (1) primary channel-fill facies, (2) chaotic flood channel-fill facies, (3) complex splay facies, (4) flood plain facies, and (5) playa facies. A model for Realitos-Mathis depositional environments shows arid-climate braided stream complexes with extremely coarse sediment load, highly variable discharge, and marked channel instability. Broad, shallow, straight to slightly sinuous primary channels were flanked by wide flood channels. Flood channels passed laterally into broad, low-relief flood plains. Small playas occupied topographic lows near large channel axes. Three facies are recognized in the Cuero and Eagle Lake mixed-load fluvial systems: (1) channel-fill facies, (2) crevasse splay facies, and (3) flood plain facies. A model for Cuero-Eagle Lake depositional environments shows coarse-grained meander belts in a semi-arid climate. Slightly to moderately sinuous meandering streams were flanked by low, poorly developed natural levees. Crevasse splays were common, but tended to be broad and ill-defined. Extensive, low-relief flood plains occupied interaxial areas. The model proposed for the Realitos and Mathis fluvial systems may aid in recognition of analogous ancient depositional systems. In addition, since facies characteristics exercise broad controls on Goliad uranium mineralization, the proposed depositional models aid in defining target zones for Goliad uranium exploration

  1. Preliminary results of chronostratigraphic field work, OSL-dating and morphogenetic reconstruction of an alluvial apron at Alborz southern foothill, Damghan basin, Iran

    Science.gov (United States)

    Büdel, Christian; Fuchs, Markus; Majid Padashi, Seyed; Baumhauer, Roland

    2014-05-01

    Here we present preliminary results of a chronostratigraphic study of an alluvial fan in the Damghan Basin, northern Iran. The basin sediments date back to the Mio- and Pliocene and therefore represent the starting point of alluvial fan aggradation. Today, the still active alluvial fans prograde from the Albors Mountain ranges and sit on the older sediment bodies. In this study, our focus is on the late Pleistocene to Holocene alluvial fan sedimentation history. The upper stratigraphy of the alluvial fans and intercalated lake deposits is characterized by six individual layers of gravels and fines, representing six different stratigraphic units. These units are described and classified by detailed geomorphological and stratigraphic mapping. To establish an alluvial fan chronology, six profiles were sampled for OSL dating. As expected, due to the high-energy transport system of alluvial fan aggradation in semi-desert environments, OSL dating of these sediments is challenging due to the problem of insufficient bleaching. Consequently, most of the samples are interpreted as maximum ages. However, the measurements show a consistent internal age structure and the overall OSL-based chronology is in agreement with the age model derived from our geomorphological analysis. As a first interpretation, based on surveyed geomorphological features and chronological analysis, we could identify seven morphodynamic phases, leading to a genetic model of alluvial fan aggradation. The oldest Pleistocene age estimate is derived from a former lake terrace. The following ages represent ongoing lake sediment deposition and the development of a proximal and mid-fan gravel cover. After the youngest lake deposits were accumulated within the Holocene, the lake starts to retreat and small alluvial fans are filling up the former lake bottom. This last sedimentation phase can be divided in at least two sub-phases, probably coupled to a lateral shifting of the active depositional lobe and to the

  2. Inference of Stream Network Fragmentation Patterns from Ground Water - Surface Water Interactions on the High Plains Aquifer

    Science.gov (United States)

    Chandler, D. G.; Yang, X.; Steward, D. R.; Gido, K.

    2007-12-01

    Stream networks in the Great Plains integrate fluxes from precipitation as surface runoff in discrete events and groundwater as base flow. Changes in land cover and agronomic practices and development of ground water resources to support irrigated agriculture have resulted in profound changes in the occurrence and magnitude of stream flows, especially near the Ogallala aquifer, where precipitation is low. These changes have demonstrably altered the aquatic habitat of western Kansas, with documented changes in fish populations, riparian communities and groundwater quality due to stream transmission losses. Forecasting future changes in aquatic and riparian ecology and groundwater quality requires a large scale spatially explicit model of groundwater- surface water interaction. In this study, we combine historical data on land use, stream flow, production well development and groundwater level observations with groundwater elevation modeling to support a geospatial framework for assessing changes in refugia for aquatic species in four rivers in western Kansas between 1965 and 2005. Decreased frequency and duration of streamflow occurred in all rivers, but the extent of change depended on the geomorphology of the river basin and the extent of groundwater development. In the absence of streamflow, refugia for aquatic species were defined as the stream reaches below the phreatic surface of the regional aquifer. Changes in extent, location and degree of fragmentation of gaining reaches was found to be a strong predictor of surface water occurrence during drought and a robust hydrological template for the analysis of changes in recharge to alluvial and regional aquifers and riparian and aquatic habitat.

  3. Radon and thoron levels, their spatial and seasonal variations in adobe dwellings - a case study at the great Hungarian plain.

    Science.gov (United States)

    Szabó, Zsuzsanna; Jordan, Gyozo; Szabó, Csaba; Horváth, Ákos; Holm, Óskar; Kocsy, Gábor; Csige, István; Szabó, Péter; Homoki, Zsolt

    2014-06-01

    Radon and thoron isotopes are responsible for approximately half of the average annual effective dose to humans. Although the half-life of thoron is short, it can potentially enter indoor air from adobe walls. Adobe was a traditional construction material in the Great Hungarian Plain. Its major raw materials are the alluvial sediments of the area. Here, seasonal radon and thoron activity concentrations were measured in 53 adobe dwellings in 7 settlements by pairs of etched track detectors. The results show that the annual average radon and thoron activity concentrations are elevated in these dwellings and that the proportions with values higher than 300 Bq m(-3) are 14-17 and 29-32% for radon and thoron, respectively. The calculated radon inhalation dose is significantly higher than the world average value, exceeding 10 mSv y(-1) in 7% of the dwellings of this study. Thoron also can be a significant contributor to the inhalation dose with about 30% in the total inhalation dose. The changes of weather conditions seem to be more relevant in the variation of measurement results than the differences in the local sedimentary geology. Still, the highest values were detected on clay. Through the year, radon follows the average temperature changes and is affected by the ventilation, whereas thoron rather seems to follow the amount of precipitation.

  4. Contribution to the hydrogeological, geochemical and isotopic study of Ain El Beidha and Merguellil (Kairouan plain) aquifers: Implication for the dam-aquifer relationship

    International Nuclear Information System (INIS)

    Ben Ammar, Safouan

    2007-01-01

    In the semiarid central part of Tunisia the water resources are becoming increasingly rare because of the scarcity and irregularity of the precipitation and a steadily growing need for fresh water. This study addresses the use of geochemical and isotopic data to analyze the relationship between the El Haouareb dam and the Ain El Beidha and the Kairouan alluvial plain aquifers systems for durable groundwater management. In the Ain El Beidha basin the hydrogeological and geochemical investigations showed that: - The general direction of the groundwater flow is mainly from the SW to the NE, i.e. towards the hydraulic sill of El Haouareb which allows the connection between the Ain El Beidha basin and the Kairouan plain, - The salinity distribution displays a zonation in apparent relationship with the lithological variation of the aquifer formation, - Mineral exchange between groundwater and the aquifer matrix is the dominant process in determining groundwater salinity. The isotopic data confirm the flow directions of groundwater and shows that the recharge of Ain El Beidha aquifers takes place from the floods of the Khechem and Ben Zitoun wadies and also by preferential infiltration of runoff at the front of hill slopes area. Close to preferential recharge areas, groundwater 3H contents reflect a recent input of surface water, whereas the radiocarbon data indicate a longer residence time downstream. The isotopic characteristics of Ain El Beidha groundwater (small space and temporal changes) authorize the use of averaged values for the dam-aquifer water exchange. Under natural conditions, groundwater recharge of the alluvial aquifer of Kairouan plain occurs by infiltration of the Merguellil floods and from the Ain el Beidha groundwater flow close the karstic hydraulic sills. Since the construction of the El Haouareb dam, these natural mechanisms have been strongly modified: the dam waters infiltrate into the karst, mix with the Ain el Beidha groundwater, and feed the

  5. Tobacco plain packaging: Evidence based policy or public health advocacy?

    Science.gov (United States)

    McKeganey, Neil; Russell, Christopher

    2015-06-01

    In December 2012, Australia became the first country to require all tobacco products be sold solely in standardised or 'plain' packaging, bereft of the manufacturers' trademarked branding and colours, although retaining large graphic and text health warnings. Following the publication of Sir Cyril Chantler's review of the evidence on the effects of plain tobacco packaging, the Ministers of the United Kingdom Parliament voted in March 2015 to implement similar legislation. Support for plain packaging derives from the belief that tobacco products sold in plain packs have reduced appeal and so are more likely to deter young people and non-smokers from starting tobacco use, and more likely to motivate smokers to quit and stay quit. This article considers why support for the plain packaging policy has grown among tobacco control researchers, public health advocates and government ministers, and reviews Australian survey data that speak to the possible introductory effect of plain packaging on smoking prevalence within Australia. The article concludes by emphasising the need for more detailed research to be undertaken before judging the capacity of the plain packaging policy to deliver the multitude of positive effects that have been claimed by its most ardent supporters. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Sustainable Authorship in Plain Text using Pandoc and Markdown

    Directory of Open Access Journals (Sweden)

    Dennis Tenen

    2014-03-01

    Full Text Available In this tutorial, you will first learn the basics of Markdown—an easy to read and write markup syntax for plain text—as well as Pandoc, a command line tool that converts plain text into a number of beautifully formatted file types: PDF, .docx, HTML, LaTeX, slide decks, and more.1 With Pandoc as your digital typesetting tool, you can use Markdown syntax to add figures, a bibliography, formatting, and easily change citation styles from Chicago to MLA (for instance, all using plain text.

  7. San Andreas Fault in the Carrizo Plain

    Science.gov (United States)

    2000-01-01

    The 1,200-kilometer (800-mile)San Andreas is the longest fault in California and one of the longest in North America. This perspective view of a portion of the fault was generated using data from the Shuttle Radar Topography Mission (SRTM), which flew on NASA's Space Shuttle last February, and an enhanced, true-color Landsat satellite image. The view shown looks southeast along the San Andreas where it cuts along the base of the mountains in the Temblor Range near Bakersfield. The fault is the distinctively linear feature to the right of the mountains. To the left of the range is a portion of the agriculturally rich San Joaquin Valley. In the background is the snow-capped peak of Mt. Pinos at an elevation of 2,692 meters (8,831 feet). The complex topography in the area is some of the most spectacular along the course of the fault. To the right of the fault is the famous Carrizo Plain. Dry conditions on the plain have helped preserve the surface trace of the fault, which is scrutinized by both amateur and professional geologists. In 1857, one of the largest earthquakes ever recorded in the United States occurred just north of the Carrizo Plain. With an estimated magnitude of 8.0, the quake severely shook buildings in Los Angeles, caused significant surface rupture along a 350-kilometer (220-mile) segment of the fault, and was felt as far away as Las Vegas, Nev. This portion of the San Andreas is an important area of study for seismologists. For visualization purposes, topographic heights displayed in this image are exaggerated two times.The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60

  8. Chemical weathering outputs from the flood plain of the Ganga

    Science.gov (United States)

    Bickle, Michael J.; Chapman, Hazel J.; Tipper, Edward; Galy, Albert; De La Rocha, Christina L.; Ahmad, Talat

    2018-03-01

    Transport of sediment across riverine flood plains contributes a significant but poorly constrained fraction of the total chemical weathering fluxes from rapidly eroding mountain belts which has important implications for chemical fluxes to the oceans and the impact of orogens on long term climate. We report water and bedload chemical analyses from the Ganges flood-plain, a major transit reservoir of sediment from the Himalayan orogen. Our data comprise six major southern tributaries to the Ganga, 31 additional analyses of major rivers from the Himalayan front in Nepal, 79 samples of the Ganga collected close to the mouth below the Farakka barrage every two weeks over three years and 67 water and 8 bedload samples from tributaries confined to the Ganga flood plain. The flood plain tributaries are characterised by a shallow δ18O - δD array, compared to the meteoric water line, with a low δDexcess from evaporative loss from the flood plain which is mirrored in the higher δDexcess of the mountain rivers in Nepal. The stable-isotope data confirms that the waters in the flood plain tributaries are dominantly derived from flood plain rainfall and not by redistribution of waters from the mountains. The flood plain tributaries are chemically distinct from the major Himalayan rivers. They can be divided into two groups. Tributaries from a small area around the Kosi river have 87Sr/86Sr ratios >0.75 and molar Na/Ca ratios as high as 6. Tributaries from the rest of the flood plain have 87Sr/86Sr ratios ≤0.74 and most have Na/Ca ratios waters have lost up to 70% of their Ca (average ∼ 50%) to precipitation of secondary calcite which is abundant as a diagenetic cement in the flood plain sediments. 31% of the Sr, 8% of the Ca and 45% of the Mg are calculated to be derived from silicate minerals. Because of significant evaporative loss of water across the flood plain, and in the absence of hydrological data for flood plain tributaries, chemical weathering fluxes from the

  9. Hydrology of area 59, northern Great Plains and Rocky Mountain coal provinces, Colorado and Wyoming

    Science.gov (United States)

    Gaggiani, Neville G.; Britton, Linda J.; Minges, Donald R.; Kilpatrick, F.A.; Parker, Randolph S.; Kircher, James E.

    1987-01-01

    Hydrologic information and analysis aid in decisions to lease federally owned coal and to prepare necessary Environmental Assessments and Impact Study reports. This need has become even more critical with the enactment of Public Law 95-87, the "Surface Mining Control and Reclamation Act of 1977." This act requires an appropriate regulatory agency to issue permits, based on the review of permit-application data to assess hydrologic impacts. This report, which partially fulfills this requirement, is one in a series of nationwide coal province reports that present information thematically, through the use of a brief text and accompanying maps, graphs, charts, or other illustrations for single hydrologic topics. The report broadly characterizes the hydrology of Area 59 in north-central Colorado and southeastern Wyoming.The report area, located within the South Platte River basin, covers a 16,000-square-mile area of diverse geology, topography, and climate. This diversity results in contrasting hydrologic characteristics.The South Platte River, the major stream in the area, and most of its tributaries originate in granitic mountains and flow into and through the sedimentary rocks of the Great Plains. Altitudes range from less than 5,000 feet to more than 14,000 feet above sea level. Precipitation in the mountains may exceed 40 inches annually, much of it during the winter, and produces deep snowpacks. Snowmelt during the spring and summer produces most streamflow. Transmountain diversion of water from the streams on the western slope of the mountains also adds to the streamflow. Precipitation in the plains is as little as 10 inches annually. Streams that originate in the plains are ephemeral.Streamflow quality is best in the mountains, where dissolved-solids concentrations are generally small. Concentrations increase in the plains as streams flow through sedimentary basins, and as urbanization and irrigation increase. The quality of some mountain streams is affected by

  10. Great Plains Wind Energy Transmission Development Project

    Energy Technology Data Exchange (ETDEWEB)

    Brad G. Stevens, P.E.; Troy K. Simonsen; Kerryanne M. Leroux

    2012-06-09

    In fiscal year 2005, the Energy & Environmental Research Center (EERC) received funding from the U.S. Department of Energy (DOE) to undertake a broad array of tasks to either directly or indirectly address the barriers that faced much of the Great Plains states and their efforts to produce and transmit wind energy at the time. This program, entitled Great Plains Wind Energy Transmission Development Project, was focused on the central goal of stimulating wind energy development through expansion of new transmission capacity or development of new wind energy capacity through alternative market development. The original task structure was as follows: Task 1 - Regional Renewable Credit Tracking System (later rescoped to Small Wind Turbine Training Center); Task 2 - Multistate Transmission Collaborative; Task 3 - Wind Energy Forecasting System; and Task 4 - Analysis of the Long-Term Role of Hydrogen in the Region. As carried out, Task 1 involved the creation of the Small Wind Turbine Training Center (SWTTC). The SWTTC, located Grand Forks, North Dakota, consists of a single wind turbine, the Endurance S-250, on a 105-foot tilt-up guyed tower. The S-250 is connected to the electrical grid on the 'load side' of the electric meter, and the power produced by the wind turbine is consumed locally on the property. Establishment of the SWTTC will allow EERC personnel to provide educational opportunities to a wide range of participants, including grade school through college-level students and the general public. In addition, the facility will allow the EERC to provide technical training workshops related to the installation, operation, and maintenance of small wind turbines. In addition, under Task 1, the EERC hosted two small wind turbine workshops on May 18, 2010, and March 8, 2011, at the EERC in Grand Forks, North Dakota. Task 2 involved the EERC cosponsoring and aiding in the planning of three transmission workshops in the midwest and western regions. Under Task

  11. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate

    Science.gov (United States)

    Scholl, M.A.; Cozzarelli, I.M.; Christenson, S.C.

    2006-01-01

    Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals in the top 2 m of the saturated zone from a leachate-contaminated well and an uncontaminated well, and analyzed for ??18O, ??2H, non-volatile dissolved organic carbon (NVDOC), SO42-, NO3- and Cl-. Monthly recharge amounts were quantified using the offset of the ??18O or ??2H from the local meteoric water line as a parameter to distinguish water types, as evaporation and methanogenesis caused isotopic enrichment in waters from different sources. Presence of dissolved SO42- in the top 1 to 2??m of the saturated zone was associated with recharge; SO42- averaged 2.2??mM, with maximum concentrations of 15??mM. Nitrate was observed near the water table at the contaminated site at concentrations up to 4.6??mM. Temporal monitoring of ??2H and SO42- showed that vertical transport of recharge carried SO42- to depths up to 1.75??m below the water table, supplying an additional electron acceptor to the predominantly methanogenic leachate plume. Measurements of ??34S in SO42- indicated both SO42- reduction and sulfide oxidation were occurring in the aquifer. Depth-integrated net SO42- reduction rates, calculated using the natural Cl- gradient as a conservative tracer, ranged from 7.5 ?? 10- 3 to 0.61??mM??d- 1 (over various depth intervals from 0.45 to 1.75??m). Sulfate reduction occurred at both the contaminated and uncontaminated sites; however, median SO42- reduction rates were higher at the contaminated site. Although estimated SO42- reduction rates are relatively high, significant decreases in NVDOC were not observed at the contaminated site. Organic compounds more labile than the leachate NVDOC may be

  12. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate.

    Science.gov (United States)

    Scholl, Martha A; Cozzarelli, Isabelle M; Christenson, Scott C

    2006-08-10

    Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals in the top 2 m of the saturated zone from a leachate-contaminated well and an uncontaminated well, and analyzed for delta(18)O, delta(2)H, non-volatile dissolved organic carbon (NVDOC), SO(4)(2-), NO(3)(-) and Cl(-). Monthly recharge amounts were quantified using the offset of the delta(18)O or delta(2)H from the local meteoric water line as a parameter to distinguish water types, as evaporation and methanogenesis caused isotopic enrichment in waters from different sources. Presence of dissolved SO(4)(2-) in the top 1 to 2 m of the saturated zone was associated with recharge; SO(4)(2-) averaged 2.2 mM, with maximum concentrations of 15 mM. Nitrate was observed near the water table at the contaminated site at concentrations up to 4.6 mM. Temporal monitoring of delta(2)H and SO(4)(2-) showed that vertical transport of recharge carried SO(4)(2-) to depths up to 1.75 m below the water table, supplying an additional electron acceptor to the predominantly methanogenic leachate plume. Measurements of delta(34)S in SO(4)(2-) indicated both SO(4)(2-) reduction and sulfide oxidation were occurring in the aquifer. Depth-integrated net SO(4)(2-) reduction rates, calculated using the natural Cl(-) gradient as a conservative tracer, ranged from 7.5x10(-3) to 0.61 mM.d(-1) (over various depth intervals from 0.45 to 1.75 m). Sulfate reduction occurred at both the contaminated and uncontaminated sites; however, median SO(4)(2-) reduction rates were higher at the contaminated site. Although estimated SO(4)(2-) reduction rates are relatively high, significant decreases in NVDOC were not observed at the contaminated

  13. Groundwater recharge and agricultural contamination in alluvial fan of Eastern Kofu basin, JAPAN

    Science.gov (United States)

    Nakamura, T.

    2009-12-01

    Agriculture has significant effects on the rate and composition of groundwater recharge. The chemical loading into groundwater have been dominated by the constituents derived directly or indirectly from agricultural practices and additives. The contamination of groundwater with nitrate is a major public health and environmental concern around the world. The inorganic constituents like, K+, Ca2+, Mg2+, SO42-, Cl- and variety of other minor elements of groundwater are often used as agricultural additives; and the natural occurrence of these elements are dominated by the agricultural sources. A recent study has reported that Kofu basin groundwater aquifer is contaminated by nitrate from agricultural areas because of the fertilizer application for the orchard (Kazama and Yoneyama, 2002; Sakamoto et al., 1997, Nakamura et al., 2007). The water-oxygen and hydrogen stable isotope (δ18O and δD) and nitrate-nitrogen stable isotope (δ15N) of groundwater, river water and precipitation samples were investigated to identify the source of groundwater and nitrate nitrogen contamination in groundwater in the Fuefukigawa and Hikawa_Kanegawa alluvial fans in Kofu basin. The plot of δD versus δ18O values of groundwater, river water and precipitation samples suggest that the groundwater is a mixture of precipitation and river water. And nitrate-nitrogen isotope values have suggested the nitrate contamination of groundwater is from agricultural area. The study revealed positive correlation between groundwater δ18O values and NO3-, Cl-, SO42-, Ca2+, Mg2+ concentration, which shows the agricultural contamination is carried by the recharge of groundwater from precipitation in alluvial fan. Whereas, NO3-, Cl-, SO42-, Ca2+, Mg2+ are diluted by the river water recharges. This study showed the quality of groundwater is resulted from the mixing of water from the different source during the groundwater recharge in the study area. References Kazama F, Yoneyama M (2002) Nitrogen generation

  14. Mars analogue alluvial fans along the Hilina Pali fault system, Island of Hawaíi

    Science.gov (United States)

    Morgan, A. M.; Craddock, R. A.

    2016-12-01

    Alluvial fans across the martian surface act as a testament to the planet's wetter past, but the magnitude and duration of runoff events and their formative environment remain poorly constrained. Here we describe the geomorphology and interpreted formative sedimentary processes of a series of coarse grained alluvial fans along the Hilina Pali fault system at the south end of the Island of Hawaíi. The Hilina Pali is a 500m fault scarp similar in slope to the interior of a crater rim, the preferential location for fan formation on Mars. Channels feeding the fans drain the Káū Desert on the leeward side of the Kilauea volcano. These channels take advantage of lava tubes and depressions in lava flows, and subsequent lava flows preferentially flow within channels. This creates a complicated stratigraphy that is difficult to interpret solely from remote sensing data. From measured channel cross sections and woody debris we calculate feeder channel discharges of 1.6-11.4 m3/s, implying runoff production rates of up to 4cm/hour. This value is in the range of rainfall that can be delivered during large cold core winter cyclones, locally known as `Kona storms', which can generate precipitation in excess of 1m/24h. While fluid is sourced from a broad area throughout the southern Káū Desert, interpolation-derived volumes of the fans and eroded alcoves above the fans suggest that fan sediment primarily is sourced directly from edge of the pali itself. We find that similar to fans on Mars, the Hilina Pali fans are relatively large relative to their contributing basin areas. However, the Hawaiian fans vary widely in their individual relations between area, slope, and grain size. We hypothesize this is due to variations in fine grained sediment supply. The fines required for increased suspension during debris flows are sourced from sand dunes and sand sheets consisting of volcanic tephra located several hundred meters north of the pali, and these dunes are unevenly

  15. 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

  16. Phosphorus availability due to polyphosphates additions to alfalfa plants grown on alluvial and calcareous soils using tracer techniques

    International Nuclear Information System (INIS)

    Ismail, A.S.; Massoud, M.A.; Shalil, K.M.E.

    1985-01-01

    A pot experiment was carried out to compare the effect of different sources and levels of condensed phosphates, including ring and chain structured molecules, with orthophosphate on alfalfa plants grown on alluvial and highly calcareous soils using P-32-labelled fertilizers. Data indicate that application of different sources of P-fertilizers increased both dry matter content and total-P uptake by alfalfa plants over control in both soils. The fraction of phosphorus in plants derived from added fertilizers was higher from condensed phosphates than that derived from the other sources of phosphorus. The percentages of P-fraction derived from added fertilizers (y-values) were higher in calcareous soil than those in alluvial soil

  17. Imaging normal faults in alluvial fans using geophysical techniques: Field example from the coast of Gulf of Aqaba, Saudi Arabia

    KAUST Repository

    Hanafy, Sherif M.

    2014-08-05

    In this work we use geophysical methods to locate and characterize active faults in alluvial sediments. Since only subtle material and velocity contrasts are expected across the faults, we used seismic refraction tomography and 2D resistivity imaging to locate the fault. One seismic profile and one 2D resistivity profile are collected at an alluvial fan on the Gulf of Aqaba coast in Saudi Arabia. The collected data are inverted to generate the traveltime tomogram and the electric resistivity tomogram (ERT). A low velocity anomaly is shown on the traveltime tomogram indicates the colluvial wedge associated with the fault. The location of the fault is shown on the ERT as a vertical high resistivity anomaly.

  18. Nonlinear Dynamical Analysis for a Plain Bearing

    Directory of Open Access Journals (Sweden)

    Ali Belhamra

    2014-03-01

    Full Text Available This paper investigates the nonlinear dynamic behavior for a plain classic bearing (fluid bearing lubricated by a non-Newtonian fluid of a turbo machine rotating with high speed; this type of fluid contains additives viscosity (couple-stress fluid film. The solution of the nonlinear dynamic problem of this type of bearing is determined with a spatial discretisation of the modified Reynolds' equation written in dynamic mode by using the optimized short bearing theory and a temporal discretisation for equations of rotor motion by the help of Euler's explicit diagram. This study analyzes the dynamic behavior of a rotor supported by two couple-stress fluid film journal lubricant enhances the dynamic stability of the rotor-bearing system considerably compared to that obtained when using a traditional Newtonian lubricant. The analysis shows that the dynamic behavior of a shaft which turns with high velocities is strongly nonlinear even for poor eccentricities of unbalance; the presence of parameters of couple stress allows strongly attenuating the will synchrony (unbalance and asynchrony (whipping amplitudes of vibrations of the shaft which supports more severe conditions (large unbalances.

  19. DNAPL migration in a coastal plain aquifer

    International Nuclear Information System (INIS)

    DiGuiseppi, W.H.; Jung, A.D.

    1995-01-01

    Soil and ground water at the Dover Gas Light Superfund Site, a former manufactured gas plant (1859 to 1948), are contaminated with polynuclear aromatic hydrocarbons and volatile organic compounds. Contaminants of concern include light aromatics, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and heavy aromatics, including naphthalene, acenaphthylene, phenanthrene, and benzo(a)pyrene. Although ground-water contaminant levels are elevated near the site, only naphthalene and acenaphthylene are present within an order of magnitude of their solubility limits, indicating the possibility of dense non-aqueous phase liquids (DNAPL) in the subsurface. The unconfined Columbia Aquifer, which is characterized by interfingering and discontinuous sand, silt, and clay Coastal Plain deposits, overlies a clay aquitard at a depth of 60 feet. The ground water beneath the intermediate clay horizon exhibited little or no contamination, even immediately downgradient from the site. The relationship between the more permeable granular sand horizons and the less permeable interfingering clay zones controls the migration of both the aqueous-phase contamination and the DNAPL. A detailed horizontal and vertical characterization of the subsurface stratigraphy was critical to the accurate interpretation of the extent and magnitude of contamination and the identification and delineation of DNAPL zones

  20. Placentation in the plains zebra (Equus quagga).

    Science.gov (United States)

    Allen, W R Twink; Stansfield, Fiona; Wilsher, Sandra

    2017-10-01

    The placenta and fetal gonads of 12 pregnant plains zebra (Equus quagga), estimated to be between 81 and 239 days of gestation, were examined. The diffuse, microcotyledonary zebra placenta appeared, developmentally, to be 3-4 weeks behind its counterpart in horse pregnancy and this, together with the presence of small and long-lived endometrial cups, low levels of zebra chorionic gonadotrophin in maternal serum and few accessory corpora lutea in the maternal ovaries during the first half of gestation, made zebra pregnancy more similar to donkey than horse pregnancy. Zebra fetal gonads enlarged after 80 days of gestation and their interstitial cells stained positively for 3β hydroxysteroid dehydrogenase and 17,20 lyase steroid enzymes while the trophoblast stained for aromatase. This confirmed that zebra fetal gonads, like those of the horse and donkey, can synthesise C19 androgens, which can then be aromatised by the placenta to C18 oestrogens. It is remarkable that such unusual feto-placental mechanisms of production of gonadotrophic and steroid hormones has persisted unchanged within the genus Equus despite the many physical adaptations and the considerable loss of chromosomes that have occurred during the evolution of its member species.

  1. Moessbauer studies on ancient Jizhon plain Temmoku porcelains

    International Nuclear Information System (INIS)

    Yu Zhengfang; Zheng Yufang; Lin Yongqiang

    1994-01-01

    Three kinds of ancient Jizhou plain Temmoku wares and their several ware-making raw materials were studied by means of X-ray diffraction (XRD) and Moessbauer spectroscopy. The firing technique of ancient Jizhou Temmoku porcelains is discussed. (orig.)

  2. Vegetation - Carrizo Plain ER, 2005 - 2008 [ds561

    Data.gov (United States)

    California Natural Resource Agency — The Vegetation Map of the Carrizo Plain Ecological Reserve, San Luis Obispo County, California was created by the California Department of Fish and Game (DFG)...

  3. Plain language: a strategic response to the health literacy challenge.

    Science.gov (United States)

    Stableford, Sue; Mettger, Wendy

    2007-01-01

    Low health literacy is a major challenge confronting American and international health organizations. Research in the past decade has documented the prevalence of limited literacy and limited health literacy skills among adults worldwide. This creates a major policy challenge: how to create text-based health information - a common method of health communication - that is accessible to the public. Plain language is a logical, flexible response. While touted by American, Canadian, and European health policy makers, adoption and promotion of plain language standards and skills in health-focused organizations have lagged. Most text-based health information continues to be too hard for most adults to read. Barriers to more rapid diffusion of plain language are reflected in a set of myths perpetuated by critics. These myths are identified and refuted. While plain language is only one of many broad-based solutions needed to address low health literacy, the benefits to everyone demand increased use by health organizations.

  4. Study on ecological regulation of coastal plain sluice

    Science.gov (United States)

    Yu, Wengong; Geng, Bing; Yu, Huanfei; Yu, Hongbo

    2018-02-01

    Coastal plains are densely populated and economically developed, therefore their importance is self-evident. However, there are some problems related with water in coastal plains, such as low flood control capacity and severe water pollution. Due to complicated river network hydrodynamic force, changeable flow direction and uncertain flood concentration and propagation mechanism, it is rather difficult to use sluice scheduling to realize flood control and tackle water pollution. On the base of the measured hydrological data during once-in-a-century Fitow typhoon in 2013 in Yuyao city, by typical analysis, theoretical analysis and process simulation, some key technologies were researched systematically including plain river network sluice ecological scheduling, “one tide” flood control and drainage scheduling and ecological running water scheduling. In the end, single factor health diagnostic evaluation, unit hydrograph of plain water level and evening tide scheduling were put forward.

  5. Types, harms and improvement of saline soil in Songnen Plain

    Science.gov (United States)

    Wang, Zhengjun; Zhuang, Jingjing; Zhao, Anping; Li, Xinxin

    2018-03-01

    Saline soil is an extremely difficult and modified soil, widely distributed around the world. According to UN-UNESCO and FAO, the world’s saline soil area is about 9.54×108hm2, and there is a growing trend, every year in 1.0×106-1.5×106hm2 speed growth, the effective utilization of land resources to the world is the most serious threat. The total area of saline-alkali land in China is about 9.91×107hm2, including the Songnen Plain, which is called one of the three major saline soil concentrations in the world. The Songnen plain is an important grain producing area in China, and the saline soil occupies most of the Songnen plain, so it is of great significance to study the saline soil and improvement in Songnen plain.

  6. Analysis of High Plains Resource Risk and Economic Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vargas, Vanessa N [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Shannon M [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dealy, Bern Caudill [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shaneyfelt, Calvin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Braeton James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moreland, Barbara Denise [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-04-01

    The importance of the High Plains Aquifer is broadly recognized as is its vulnerability to continued overuse. T his study e xplore s how continued depletions of the High Plains Aquifer might impact both critical infrastructure and the economy at the local, r egional , and national scale. This analysis is conducted at the county level over a broad geographic region within the states of Kansas and Nebraska. In total , 140 counties that overlie the High Plains Aquifer in these two states are analyzed. The analysis utilizes future climate projections to estimate crop production. Current water use and management practices are projected into the future to explore their related impact on the High Plains Aquifer , barring any changes in water management practices, regulat ion, or policy. Finally, the impact of declining water levels and even exhaustion of groundwater resources are projected for specific sectors of the economy as well as particular elements of the region's critical infrastructure.

  7. Plain abdominal radiographs in acute medical emergencies: an abused investigation?

    Science.gov (United States)

    Feyler, S; Williamson, V; King, D

    2002-02-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

  8. The Great Plains IDEA Gerontology Program: An Online, Interinstitutional Graduate Degree

    Science.gov (United States)

    Sanders, Gregory F.

    2011-01-01

    The Great-Plains IDEA Gerontology Program is a graduate program developed and implemented by the Great Plains Interactive Distance Education Alliance (Great Plains IDEA). The Great Plains IDEA (Alliance) originated as a consortium of Colleges of Human Sciences ranging across the central United States. This Alliance's accomplishments have included…

  9. The innovation of nuclear science and technology supporting for the central plains economic zone construction

    International Nuclear Information System (INIS)

    Yang Xiaowei

    2014-01-01

    This paper discusses the nuclear agronomy support for the central plains economic zone construction, radiation chemical new material support for the central plains economic zone construction, nuclear medical support for the central plains economic zone construction, nuclear instrument and meter industry support for the central plains economic zone construction and the development trend of related disciplines. (author)

  10. Holocene alluvial stratigraphy and response to climate change in the Roaring River valley, Front Range, Colorado, USA

    Science.gov (United States)

    Madole, Richard F.

    2012-09-01

    Stratigraphic analyses and radiocarbon geochronology of alluvial deposits exposed along the Roaring River, Colorado, lead to three principal conclusions: (1) the opinion that stream channels in the higher parts of the Front Range are relics of the Pleistocene and nonalluvial under the present climate, as argued in a water-rights trial USA v. Colorado, is untenable, (2) beds of clast-supported gravel alternate in vertical succession with beds of fine-grained sediment (sand, mud, and peat) in response to centennial-scale changes in snowmelt-driven peak discharges, and (3) alluvial strata provide information about Holocene climate history that complements the history provided by cirque moraines, periglacial deposits, and paleontological data. Most alluvial strata are of late Holocene age and record, among other things, that: (1) the largest peak flows since the end of the Pleistocene occurred during the late Holocene; (2) the occurrence of a mid- to late Holocene interval (~ 2450-1630(?) cal yr BP) of warmer climate, which is not clearly identified in palynological records; and (3) the Little Ice Age climate seems to have had little impact on stream channels, except perhaps for minor (~ 1 m) incision.

  11. Determination of gold in auriferous alluvial sands and rocks by 14 MeV neutron activation analysis

    International Nuclear Information System (INIS)

    Ene, A.; Nat, A.; Lupu, R.; Popescu, I.V.

    2004-01-01

    In this work a complex study of the interferences which appear in gold determination by 14 MeV neutron activation analysis of some Romanian auriferous alluvial sands and rocks has been carried out. The contribution of the nuclear interfering elements - Hg and Pt - to the concentration of gold in the samples is minimum in the case of the nuclear reactions 197 Au (n, 2n) 196 Au, 197 Au (n, 2n) 196m Au and 197 Au (n, n') 197m Au. As regards the spectral interferences, these are minimum in the case of using the reactions 197 Au (n, n') 197m Au and 197 Au (n, 2n) 196 Au and are due to Rb, Ti and V for short irradiation and to Se for long irradiation. We propose two methods of gold determination in auriferous alluvial sands and rocks in the range 20-2500 ppm - the minimum value of 20 ppm being at the level of an economic extraction - in the optimum conditions established by us so that the systematic errors of analysis due to the gold accompanying elements should be considerably diminished: a method using short irradiation (25s) and NaI(Tl) spectrometry for measuring the induced gamma radioactivity in the samples and a method using long irradiation (3000s) and Ge(Li) spectrometry. The data presented in this paper can be adapted by other analysts to the rapid determination of gold in a variety of alluvial sands and rocks. (authors)

  12. Lithology, hydrologic characteristics, and water quality of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas

    Science.gov (United States)

    Kresse, Timothy M.; Westerman, Drew A.; Hart, Rheannon M.

    2015-01-01

    A study to assess the potential of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas, as a viable source of public-supply water was conducted by the U.S. Geological Survey in cooperation with the Little Rock, District, U.S. Army Corps of Engineers. An important study component was to identify possible changes in hydrologic conditions following installation of James W. Trimble Lock and Dam 13 (December 1969) on the Arkansas River near the study area. Data were gathered for the study in regard to the lithology, hydrologic characteristics, and water quality of the aquifer. Lithologic information was obtained from drillers’ logs of wells drilled from 1957 through 1959. Water-quality samples were collected from 10 irrigation wells and analyzed for inorganic constituents and pesticides. To evaluate the potential viability of the alluvial aquifer in the Van Buren area, these data were compared to similar stratigraphic, lithologic, and groundwater-quality data from the Arkansas River Valley alluvial aquifer at Dardanelle, Ark., where the aquifer provides a proven, productive, sole-source of public-supply water.

  13. Application of geoecological concept of the alluvial landscape in the creation of nature reserve (case study from Czech Republic

    Directory of Open Access Journals (Sweden)

    Ivo Machar

    2011-01-01

    Full Text Available The geoecological concept of the alluvial landscape describes the variability and consecutive character of alluvial ecotopes and biocenoses, which are interrelated in terms of their homeorhetic development, in their dynamic ecological stability. This article deals with application of this landscape concept in the frame of creation of nature reserve as core zone of the Litovelské Pomoraví Protected Landscape Area (Czech Republic. Complex protection of the whole floodplain ecosystem, which comprised all components of the fluvial succession series of alluvial habitats, was proposed on the basis of determination of geomorphological type of the river system. Analyses of the floodplain forest stands status within the study area were performed using methods that are normally used in the elaboration of management plans of protected areas within forest land on the basis of data from Forest Management Plan. The area of the proposed NNR was created by the overlay of the special map layers using method gap-analysis in the frame of GIS.

  14. No (more) logo: plain packaging and communicative agency

    OpenAIRE

    Alain Pottage

    2013-01-01

    The tobacco industry’s archives suggest that the global campaign for the plain packaging of tobacco products originated in 1986, when the Canadian Medical Association passed a resolution calling for cigarettes to be sold in packages bearing only a brand name and the health message ‘this product is injurious to your health’. In most jurisdictions, regulations requiring the apposition of health warnings to cigarette packs have been in force for decades. Proposals for plain packaging aim to go f...

  15. Geology and ground-water conditions of Clark County Washington, with a description of a major alluvial aquifer along the Columbia River

    Science.gov (United States)

    Mundorff, Maurice John

    1964-01-01

    This report presents the results of an investigation of the ground-water resources of the populated parts of Clark County. Yields adequate for irrigation can be obtained from wells inmost farmed areas in Clark County, Wash. The total available supply is sufficient for all foreseeable irrigation developments. In a few local areas aquifers are fine-grained, and yields of individual wells are low. An enormous ground-water supply is available from a major alluvial aquifer underlying the flood plain of the Columbia River in the vicinity of Vancouver, Camas, and Washougal, where the aquifer is recharged, in part, by infiltration from the river. Yields of individual wells are large, ranging to as much as 4,000 gpm (gallons per minute). Clark County lies along the western flank of the Cascade Range. in the structural lowland (Willamette-Puget trough) between those mountains and the Coast Ranges to the west. The area covered by the report includes the urban, the suburban, and most of the agricultural lands in the county. These lands lie on a Series of nearly fiat plains and benches which rise steplike from the level of the Columbia River (a few feet above sea level) to about 800 feet above sea level. Clark County is-drained by the Columbia River (the trunk stream of the Pacific Northwest) and its tributaries. The Columbia River forms the southern and western boundaries of the county. Although the climate of the county is considered to be humid, the precipitation ranging from about 37 to more than 110 inches annually in various parts of the county, the unequal seasonal distribution (about 1.5 inches total for ;July and August in the agricultural area) makes irrigation highly desirable for most .crops and essential for some specialized crops. Consolidated rocks of Eocene to Miocene age, chiefly volcanic lava flows and pyroclastics but including some sedimentary strata, crop out in the foothills of the Cascades in the eastern part of the county and underlie the younger

  16. Sedimentology and paleoecology of an Eocene Oligocene alluvial lacustrine arid system, Southern Mexico

    Science.gov (United States)

    Beraldi-Campesi, Hugo; Cevallos-Ferriz, Sergio R. S.; Centeno-García, Elena; Arenas-Abad, Concepción; Fernández, Luis Pedro

    2006-10-01

    A depositional model of the Eocene-Oligocene Coatzingo Formation in Tepexi de Rodríguez (Puebla, Mexico) is proposed, based on facies analysis of one of the best-preserved sections, the Axamilpa Section. The sedimentary evolution is interpreted as the retrogradation of an alluvial system, followed by the progressive expansion of an alkaline lake system, with deltaic, palustrine, and evaporitic environments. The analysis suggests a change towards more arid conditions with time. Fossils from this region, such as fossil tracks of artiodactyls, aquatic birds and cat-like mammals, suggest that these animals traversed the area, ostracods populated the lake waters, and plants grew on incipient soils and riparian environments many times throughout the history of the basin. The inferred habitat for some fossil plants coincides with the sedimentological interpretation of an arid to semiarid climate for that epoch. This combined sedimentological-paleontological study of the Axamilpa Section provides an environmental context in which fossils can be placed and brings into attention important biotic episodes, like bird and camelid migrations or the origin of endemic but extinct plants in this area.

  17. Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer

    Science.gov (United States)

    Quamar, Rafat; Jangam, C.; Veligeti, J.; Chintalapudi, P.; Janipella, R.

    2017-12-01

    The present study is an attempt to study the impact of the On-site sanitation system on the groundwater sources in its vicinity. The study has been undertaken in the Agra city of Yamuna sub-basin. In this context, sampling sites (3 nos) namely Pandav Nagar, Ayodhya Kunj and Laxmi Nagar were selected for sampling. The groundwater samples were analyzed for major cations, anions and faecal coliform. Critical parameters namely chloride, nitrate and Faecal coliform were considered to assess the impact of the On-site sanitation systems. The analytical results shown that except for chloride, most of the samples exceeded the Bureau of Indian Standard limits for drinking water for all the other analyzed parameters, i.e., nitrate and faecal coliform in the first two sites. In Laxmi Nagar, except for faecal coliform, all the samples are below the BIS limits. In all the three sites, faecal coliform was found in majority of the samples. A comparison of present study indicates that the contamination of groundwater in alluvial setting is less as compared to hard rock where On-site sanitation systems have been implemented.

  18. Nitrogen-isotope ratio studies of soils and groundwater nitrate from alluvial fan aquifers in Texas

    International Nuclear Information System (INIS)

    Kreitler, C.W.

    1979-01-01

    Kreitler has previously identified two ranges of nitrogen-isotope values (delta 15 N) for soil nitrate under different land uses in west Texas: nitrate originating from nonfertilized, cultivated fields (delta 14 N range, 2 to +8per thousand with an average of +4.9per thousand), and nitrate from animal wastes (delta 15 N range, +10 to +22per thousand with an average of +14.4per thousand). The delta 15 N of groundwater nitrate from irrigation wells on the Lockhart and Taylor and alluvial fans range from +3.3 to +10.8per thousand with an average of +7.3per thousand. Ground water from domestic wells on the two fans has higher nitrate concentrations and a more positive delta 15 N range (+6.7 to 18.2per thousand with an average of +11.1per thousand) than wells located in the cultivated fields. Nitrate contamination of wells located in cultivated fields results primarily from cultivation with ammonium-type fertilizers, whereas animal wastes are contaminating domestic well waters. (Auth.)

  19. The Lower Cretaceous Way Group of northern Chile: An alluvial fan-fan delta complex

    Science.gov (United States)

    Flint, S.; Clemmey, H.; Turner, P.

    1986-01-01

    Alluvial fan sediments of the Lower Cretaceous Coloso Basin in northern Chile were deposited in a half-graben and derived from andesitic volcanics of a former island arc. Transport directions were towards the east, away from the present-day Peru-Chile trench. Grain flow, density modified grain flow and sheetflow processes were responsible for most of the sediment deposition with cohesive debris flows playing only a minor part. An early phase of conglomerate deposition (Coloso Formation) into a restricted basin records the transition from proximal fan facies with abundant grain flows and remobilized screes to mid-fan facies dominated by sheetflows. Stratiform copper mineralization near the top of the lower conglomerates is related to the unroofing of the Jurassic island arc. This mineralization comprises copper sulphide-cemented sands and gravels and formed by the reaction of mineralized detritus with diagenetic and hydrothermal solutions. A later phase of deposition (Lombriz Formation) includes sandstones, siltstones and conglomerates with a source area different from the Coloso Formation. This change in source may be related to strike-slip tectonics as the basin extended. The Lombriz conglomerates pass distally (eastwards) into red sandstones and purple siltstones with thin limestones deposited under marine conditions. This sequence is interpreted as a major fan delta complex. It passes conformably into marine carbonates of the Tableado Formation signifying the complete drowning of the basin in lower Cretaceous times.

  20. Using solute and heat tracers for aquifer characterization in a strongly heterogeneous alluvial aquifer

    Science.gov (United States)

    Sarris, Theo S.; Close, Murray; Abraham, Phillip

    2018-03-01

    A test using Rhodamine WT and heat as tracers, conducted over a 78 day period in a strongly heterogeneous alluvial aquifer, was used to evaluate the utility of the combined observation dataset for aquifer characterization. A highly parameterized model was inverted, with concentration and temperature time-series as calibration targets. Groundwater heads recorded during the experiment were boundary dependent and were ignored during the inversion process. The inverted model produced a high resolution depiction of the hydraulic conductivity and porosity fields. Statistical properties of these fields are in very good agreement with estimates from previous studies at the site. Spatially distributed sensitivity analysis suggests that both solute and heat transport were most sensitive to the hydraulic conductivity and porosity fields and less sensitive to dispersivity and thermal distribution factor, with sensitivity to porosity greatly reducing outside the monitored area. The issues of model over-parameterization and non-uniqueness are addressed through identifiability analysis. Longitudinal dispersivity and thermal distribution factor are highly identifiable, however spatially distributed parameters are only identifiable near the injection point. Temperature related density effects became observable for both heat and solute, as the temperature anomaly increased above 12 degrees centigrade, and affected down gradient propagation. Finally we demonstrate that high frequency and spatially dense temperature data cannot inform a dual porosity model in the absence of frequent solute concentration measurements.

  1. Organic and chemical manure of the bean (Phaseolus vulgaris) in alluvial soils of intermediate climate

    International Nuclear Information System (INIS)

    Tamayo V, Alvaro; Munoz A, Rodrigo

    1997-01-01

    With the purpose to evaluate the effect on bean production ICA CITARA variety, four sources of organic matter (hen manure, pig manure, cow manure, and earthworm manure) in four doses 280,500 y 1.000 kg/ha with the same doses of chemical fertilization, were evaluated the experiment was carried out at Tulio Ospina Research Center, located at Bello (Antioquia) of medium climate with 1.320 m.s.n.m. This was established using an alluvial soil (Tropofluvent), frenk, with low contents of organic, matter (2,2%), phosphorus (10 ppm), and potassium (0,10 meq/l00 g). the results, after six consecutive harvests on the same plots, showed highly significative differences among treatments. The highest yield (1.836 kg/ha) was obtained when to the chemical fertilization (300 kg of 10-30-10) was added with 250 kg/ha of hen manure, followed by the application of 100 kg/ha, of cow manure (1.812 kg/ha). Chemical fertilization without organic matter produced 1.640 kg/ha of bean, which was very similar to the addition of 1.000 kg/ha of cow manure and earthworm manure with yields of 1.688 kg/ha and 1.635 kg/ha respectively

  2. Mechanisms of vegetation uprooting by flow in alluvial non-cohesive sediment

    Directory of Open Access Journals (Sweden)

    K. Edmaier

    2011-05-01

    Full Text Available The establishment of riparian pioneer vegetation is of crucial importance within river restoration projects. After germination or vegetative reproduction on river bars juvenile plants are often exposed to mortality by uprooting caused by floods. At later stages of root development vegetation uprooting by flow is seen to occur as a consequence of a marked erosion gradually exposing the root system and accordingly reducing the mechanical anchoring. How time scales of flow-induced uprooting do depend on vegetation stages growing in alluvial non-cohesive sediment is currently an open question that we conceptually address in this work. After reviewing vegetation root issues in relation to morphodynamic processes, we then propose two modelling mechanisms (Type I and Type II, respectively concerning the uprooting time scales of early germinated and of mature vegetation. Type I is a purely flow-induced drag mechanism, which causes alone a nearly instantaneous uprooting when exceeding root resistance. Type II arises as a combination of substantial sediment erosion exposing the root system and resulting in a decreased anchoring resistance, eventually degenerating into a Type I mechanism. We support our conceptual models with some preliminary experimental data and discuss the importance of better understanding such mechanisms in order to formulate sounding mathematical models that are suitable to plan and to manage river restoration projects.

  3. Modelling stream aquifer seepage in an alluvial aquifer: an improved loosing-stream package for MODFLOW

    Science.gov (United States)

    Osman, Yassin Z.; Bruen, Michael P.

    2002-07-01

    Seepage from a stream, which partially penetrates an unconfined alluvial aquifer, is studied for the case when the water table falls below the streambed level. Inadequacies are identified in current modelling approaches to this situation. A simple and improved method of incorporating such seepage into groundwater models is presented. This considers the effect on seepage flow of suction in the unsaturated part of the aquifer below a disconnected stream and allows for the variation of seepage with water table fluctuations. The suggested technique is incorporated into the saturated code MODFLOW and is tested by comparing its predictions with those of a widely used variably saturated model, SWMS_2D simulating water flow and solute transport in two-dimensional variably saturated media. Comparisons are made of both seepage flows and local mounding of the water table. The suggested technique compares very well with the results of variably saturated model simulations. Most currently used approaches are shown to underestimate the seepage and associated local water table mounding, sometimes substantially. The proposed method is simple, easy to implement and requires only a small amount of additional data about the aquifer hydraulic properties.

  4. Liquefaction analysis of alluvial soil deposits in Bedsa south west of Cairo

    Directory of Open Access Journals (Sweden)

    Kamal Mohamed Hafez Ismail Ibrahim

    2014-09-01

    Full Text Available Bedsa is one of the districts in Dahshour that lays south west of Cairo and suffered from liquefaction during October 1992 earthquake, Egypt. The soil profile consists of alluvial river Nile deposits mainly sandy mud with low plasticity; the ground water is shallow. The earthquake hypocenter was 18 km far away with local magnitude 5.8; the fault length was 13.8 km, as recorded by the Egyptian national seismological network (ENSN at Helwan. The analysis used the empirical method introduced by the national center for earthquake engineering research (NCEER based on field standard penetration of soil. It is found that the studied area can liquefy since there are saturated loose sandy silt layers at depth ranges from 7 to 14 m. The settlement is about 26 cm. The probability of liquefaction ranges between 40% and 100%. The presence of impermeable surface from medium cohesive silty clay acts as a plug resisting and trapping the upward flow of water during liquefaction, so fountain and spouts at weak points occurs. It is wise to use point bearing piles with foundation level deeper than 14 m beyond the liquefiable depth away from ground slopes, otherwise liquefaction improving techniques have to be applied in the area.

  5. A morphological comparison of narrow, low-gradient streams traversing wetland environments to alluvial streams.

    Science.gov (United States)

    Jurmu, Michael C

    2002-12-01

    Twelve morphological features from research on alluvial streams are compared in four narrow, low-gradient wetland streams located in different geographic regions (Connecticut, Indiana, and Wisconsin, USA). All four reaches differed in morphological characteristics in five of the features compared (consistent bend width, bend cross-sectional shape, riffle width compared to pool width, greatest width directly downstream of riffles, and thalweg location), while three reaches differed in two comparisons (mean radius of curvature to width ratio and axial wavelength to width ratio). The remaining five features compared had at least one reach where different characteristics existed. This indicates the possibility of varying morphology for streams traversing wetland areas further supporting the concept that the unique qualities of wetland environments might also influence the controls on fluvial dynamics and the development of streams. If certain morphological features found in streams traversing wetland areas differ from current fluvial principles, then these varying features should be incorporated into future wetland stream design and creation projects. The results warrant further research on other streams traversing wetlands to determine if streams in these environments contain unique morphology and further investigation of the impact of low-energy fluvial processes on morphological development. Possible explanations for the morphology deviations in the study streams and some suggestions for stream design in wetland areas based upon the results and field observations are also presented.

  6. Magnetic properties of alluvial soils contaminated with lead, zinc and cadmium

    Science.gov (United States)

    Petrovský, E.; Kapička, A.; Jordanova, N.; Borůvka, L.

    2001-09-01

    Several proxy methods have been used recently to outline increased levels of pollution. One of them is based on measurements of the concentration of (ferri)magnetic minerals of anthropogenic origin. This method has been used recently in the mapping of both polluted and unpolluted areas. In order to validate this method, a more detailed study of links between magnetic parameters characterising the physical shape of magnetic minerals and concentrations of heavy metals is needed. In this study, we analysed the magnetic characteristics of alluvial soils, formed as a result of several breakdowns of wet deposit sink of ashes from a lead ore smelter. The soils were previously analysed for concentration of lead, zinc and cadmium. Our results show that in this case of a shared source of heavy metals and magnetic minerals, simple measurements of magnetic susceptibility discriminate well between polluted and clean areas. In addition, the concentration pattern agrees with the concentrations of the heavy metals studied in deeper soil layers that were not affected by post-depositional changes due to climate and remediation efforts.

  7. An Investigation of the Uniaxial Compressive Strength of a Cemented Hydraulic Backfill Made of Alluvial Sand

    Directory of Open Access Journals (Sweden)

    Guangsheng Liu

    2017-01-01

    Full Text Available Backfill is commonly used in underground mines. The quality control of the backfill is a key step to ensure it meets the designed strength requirement. This is done through sample collection from the underground environment, followed by uniaxial compression tests to obtain the Uniaxial Compressive Strength (UCS in the laboratory. When the cylindrical cemented backfill samples are axially loaded to failure, several failure modes can be observed and mainly classified into diagonal shear failure and axial split failure. To date, the UCS obtained by these two failure modes are considered to be the same with no distinction between them. In this paper, an analysis of the UCS results obtained on a cemented hydraulic backfill made of alluvial sand at a Canadian underground mine over the course of more than three years is presented. The results show that the UCS values obtained by diagonal shear failure are generally higher than those obtained by axial split failure for samples with the same recipe and curing time. This highlights the importance of making a distinction between the UCS values obtained by the two different modes of failure. Their difference in failure mechanism is explained. Further investigations on the sources of the data dispersion tend to indicate that the UCS obtained by laboratory tests following the current practice may not be representative of the in-situ strength distribution in the underground stopes due to segregation in cemented hydraulic backfill.

  8. River banks and channel axis curvature: Effects on the longitudinal dispersion in alluvial rivers

    Science.gov (United States)

    Lanzoni, Stefano; Ferdousi, Amena; Tambroni, Nicoletta

    2018-03-01

    The fate and transport of soluble contaminants released in natural streams are strongly dependent on the spatial variations of the flow field and of the bed topography. These variations are essentially related to the presence of the channel banks and to the planform configuration of the channel. Large velocity gradients arise near to the channel banks, where the flow depth decreases to zero. Moreover, single thread alluvial rivers are seldom straight, and usually exhibit meandering planforms and a bed topography that deviates from the plane configuration. Channel axis curvature and movable bed deformations drive secondary helical currents which enhance both cross sectional velocity gradients and transverse mixing, thus crucially influencing longitudinal dispersion. The present contribution sets up a rational framework which, assuming mild sloping banks and taking advantage of the weakly meandering character often exhibited by natural streams, leads to an analytical estimate of the contribution to longitudinal dispersion associated with spatial non-uniformities of the flow field. The resulting relationship stems from a physics-based modeling of the flow in natural rivers, and expresses the bend averaged longitudinal dispersion coefficient as a function of the relevant hydraulic and morphologic parameters. The treatment of the problem is river specific, since it relies on an explicit spatial description, although linearized, of the flow field that establishes in the investigated river. Comparison with field data available from tracer tests supports the robustness of the proposed framework, given also the complexity of the processes that affect dispersion dynamics in real streams.

  9. Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley

    Science.gov (United States)

    Lichtenberg, J.S.; King, S.L.; Grace, J.B.; Walls, S.C.

    2006-01-01

    Amphibian populations have declined worldwide. To pursue conservation efforts adequately, land managers need more information concerning amphibian habitat requirements. To address this need, we examined relationships between anurans and habitat characteristics of wetlands in the Lower Mississippi River Alluvial Valley (LMAV). We surveyed chorusing anurans in 31 wetlands in 2000 and 28 wetlands in 2001, and measured microhabitat variables along the shoreline within the week following each survey. We recorded 12 species of anurans during our study. Species richness was significantly lower in 2000 than 2001 (t-test, P < 0.001) and correlated with an ongoing drought. We found species richness to be significantly greater at lake sites compared to impoundment, swale, and riverine sites (ANOVA, P = 0.002). We used stepwise regression to investigate the wetland types and microhabitat characteristics associated with species richness of chorusing anurans. Microhabitat characteristics associated with species richness included dense herbaceous vegetation and accumulated litter along the shoreline. Individual species showed species-specific habitat associations. The bronze frog, American bullfrog, and northern cricket frog were positively associated with lake sites (Fisher's Exact Test, P < 0.05), however wetland type did not significantly influence any additional species. Using bivariate correlations, we found that six of the seven most common species had significant associations with microhabitat variables. Overall, our findings support the view that conservation and enhancement of amphibian communities in the LMAV and elsewhere requires a matrix of diverse wetland types and habitat conditions. ?? 2006, The Society of Wetland Scientists.

  10. Hierarchy in factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    Science.gov (United States)

    Dembkowski, D.J.; Miranda, L.E.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts. ?? 2011 Springer Science+Business Media B.V.

  11. Factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    Science.gov (United States)

    Miranda, Leandro E.; Dembkowski, Daniel J.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts.

  12. Balancing lake ecological condition and agriculture irrigation needs in the Mississippi Alluvial Valley

    Science.gov (United States)

    Miranda, Leandro E.; Omer, A.R.; Killgore, K.J.

    2017-01-01

    The Mississippi Alluvial Valley includes hundreds of floodplain lakes that support unique fish assemblages and high biodiversity. Irrigation practices in the valley have lowered the water table, increasing the cost of pumping water, and necessitating the use of floodplain lakes as a source of water for irrigation. This development has prompted the need to regulate water withdrawals to protect aquatic resources, but it is unknown how much water can be withdrawn from lakes before ecological integrity is compromised. To estimate withdrawal limits, we examined descriptors of lake water quality (i.e., total nitrogen, total phosphorus, turbidity, Secchi visibility, chlorophyll-a) and fish assemblages (species richness, diversity, composition) relative to maximum depth in 59 floodplain lakes. Change-point regression analysis was applied to identify critical depths at which the relationships between depth and lake descriptors exhibited a rapid shift in slope, suggesting possible thresholds. All our water quality and fish assemblage descriptors showed rapid changes relative to depth near 1.2–2.0 m maximum depth. This threshold span may help inform regulatory decisions about water withdrawal limits. Alternatives to explain the triggers of the observed threshold span are considered.

  13. Influence of hydrologic modifications on Fraxinus pennsylvanica in the Mississippi River Alluvial Valley, USA

    Science.gov (United States)

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

    2015-01-01

    We used tree-ring analysis to examine radial growth response of a common, moderately flood-tolerant species (Fraxinus pennsylvanica Marshall) to hydrologic and climatic variability for > 40 years before and after hydrologic modifications affecting two forest stands in the Mississippi River Alluvial Valley (USA): a stand without levees below dams and a stand within a ring levee. At the stand without levees below dams, spring flood stages decreased and overall growth increased after dam construction, which we attribute to a reduction in flood stress. At the stand within a ring levee, growth responded to the elimination of overbank flooding by shifting from being positively correlated with river stage to not being correlated with river stage. In general, growth in swales was positively correlated with river stage and Palmer Drought Severity Index (an index of soil moisture) for longer periods than flats. Growth decreased after levee construction, but swales were less impacted than flats likely because of differences in elevation and soils provide higher soil moisture. Results of this study indicate that broad-scale hydrologic processes differ in their effects on the flood regime, and the effects on growth of moderately flood-tolerant species such as F. pennsylvanica can be mediated by local-scale factors such as topographic position, which affects soil moisture.

  14. Exchangeable fraction of elements in alluvial sediments under waste disposal site (Zagreb, Croatia)

    International Nuclear Information System (INIS)

    Vertacnik, A.; Barisic, D.; Musani, Lj.; Prohic, E.; Juracic, M.

    1997-01-01

    Concentrations of Ag, Ba, Cd, Ce, Cs, Co, Cr, Eu, Fe, Rb, Sc, Sr, Th, and Zn exchangeable fractions were determined in alluvial sediments at waste disposal site area in the vicinity of water-well field. Samples have been'leached with 0.5M NH 4 Cl at a sample/solution ratio of 1:20 during 24 hours without shaking. INAA of dry NH 4 Cl residues show that the concentrations of exchangeable elements determined in the most of the sediments below the wastes have natural levels. Ag, Ba and Sr are readily exchangeable; Rb, Cs and Zn have lower exchangeability, while Cd, Ce, Th, Sc, Eu, Cr, Fe and Co are rather immobile. Extremely high total and exchangeable silver concentration was found at 6.5-6.8 meters below waste in the aerated layer occasionally under the water table. Exchangeable concentrations in deeper water-bearing sediment layers are not elevated. Due to this, one can presume that the upper sediment layers act as chemical filter generally preventing the infiltration from overlying wastes into water-bearing layers. (author)

  15. Groundwater movement, recharge, and perchlorate occurrence in a faulted alluvial aquifer in California (USA)

    Science.gov (United States)

    Izbicki, John A.; Teague, Nicholas F.; Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.

    2015-01-01

    Perchlorate from military, industrial, and legacy agricultural sources is present within an alluvial aquifer in the Rialto-Colton groundwater subbasin, 80 km east of Los Angeles, California (USA). The area is extensively faulted, with water-level differences exceeding 60 m across parts of the Rialto-Colton Fault separating the Rialto-Colton and Chino groundwater subbasins. Coupled well-bore flow and depth-dependent water-quality data show decreases in well yield and changes in water chemistry and isotopic composition, reflecting changing aquifer properties and groundwater recharge sources with depth. Perchlorate movement through some wells under unpumped conditions from shallower to deeper layers underlying mapped plumes was as high as 13 kg/year. Water-level maps suggest potential groundwater movement across the Rialto-Colton Fault through an overlying perched aquifer. Upward flow through a well in the Chino subbasin near the Rialto-Colton Fault suggests potential groundwater movement across the fault through permeable layers within partly consolidated deposits at depth. Although potentially important locally, movement of groundwater from the Rialto-Colton subbasin has not resulted in widespread occurrence of perchlorate within the Chino subbasin. Nitrate and perchlorate concentrations at the water table, associated with legacy agricultural fertilizer use, may be underestimated by data from long-screened wells that mix water from different depths within the aquifer.

  16. Major periods of erosion and alluvial sedimentation in New Zealand during the Late Holocene

    International Nuclear Information System (INIS)

    Grant, P.J.

    1985-01-01

    During the last 1,800 years there have been eight major periods of erosion and alluvial sedimentation in New Zealand. These and their probable times of occurrence are: Taupo (1,l764 years BP), Post-Taupo (1,600-1,500 years BP), Pre-Kaharoa (1,300-900 years BP), Waihirere (680-600 years BP), Matawhero (450-330 years BP), Wakarara (180-150 years BP), Tamaki (1870-1900 AD) and Waipawa (1950 to present). The Taupo period, which is identified only in North Island, possibly resulted from heavy rainfalls induced by the Taupo Pumice eruption. The other seven periods, which probably occurred universally in both main islands of New Zealand, were almost certainly caused by increased northerly airflow and atmospheric warming over New Zealand, and the associated increased magnitude of major rainstorms and floods, producing increased rates of erosion and channel sediment transport. Such changes were due primarily to a temporary strengthening of the meridional upper atmospheric circulation in the Southwest Pacific region

  17. Valuing ecosystem services from wetlands restoration in the Mississippi Alluvial Valley

    Science.gov (United States)

    Jenkins, W.A.; Murray, B.C.; Kramer, R.A.; Faulkner, S.P.

    2010-01-01

    This study assesses the value of restoring forested wetlands via the U.S. government's Wetlands Reserve Program (WRP) in the Mississippi Alluvial Valley by quantifying and monetizing ecosystem services. The three focal services are greenhouse gas (GHG) mitigation, nitrogen mitigation, and waterfowl recreation. Site- and region-level measurements of these ecosystem services are combined with process models to quantify their production on agricultural land, which serves as the baseline, and on restored wetlands. We adjust and transform these measures into per-hectare, valuation-ready units and monetize them with prices from emerging ecosystem markets and the environmental economics literature. By valuing three of the many ecosystem services produced, we generate lower bound estimates for the total ecosystem value of the wetlands restoration. Social welfare value is found to be between $1435 and $1486/ha/year, with GHG mitigation valued in the range of $171 to $222, nitrogen mitigation at $1248, and waterfowl recreation at $16. Limited to existing markets, the estimate for annual market value is merely $70/ha, but when fully accounting for potential markets, this estimate rises to $1035/ha. The estimated social value surpasses the public expenditure or social cost of wetlands restoration in only 1 year, indicating that the return on public investment is very attractive for the WRP. Moreover, the potential market value is substantially greater than landowner opportunity costs, showing that payments to private landowners to restore wetlands could also be profitable for individual landowners. ?? 2009 Elsevier B.V.

  18. Stochastic Spectral Analysis for Characterizing Hydraulic Diffusivity in an Alluvial Fan Aquifer with River Stimulus

    Science.gov (United States)

    Wang, Y. L.; Zha, Y.; Yeh, T. C. J.; Wen, J. C.

    2015-12-01

    Estimation of subsurface hydraulic diffusivity was carried out to understand the characteristics of Zhuoshui River alluvial fan, Taiwan. The fan, an important agricultural and industrial region with high water demand, is located at middle Taiwan with an area of 1800 km2. The prior geo-investigations suggest that the main recharge region of the fan is at an apex along the river. The distribution of soil hydraulic diffusivity was estimated by fusing naturally recurring stimulus provided by river and groundwater head. Specifically, the variance and power spectrum provided by temporal and spatial change of groundwater head in response to river stage variations are analyzed to estimate hydraulic diffusivity distribution. It is found that the hydraulic diffusivity of the fan is at the range from 0.08 to 16 m2/s. The average hydraulic diffusivity at the apex, middle, and tail of the fan along the river is about 0.4, 0.6, and 1.0 m2/s, respectively.

  19. The Influence of Syndepositional Macropores on the Hydraulic Integrity of Thick Alluvial Clay Aquitards

    Science.gov (United States)

    Timms, Wendy A.; Acworth, R. Ian; Crane, Richard A.; Arns, Christoph H.; Arns, Ji-Youn; McGeeney, Dayna E.; Rau, Gabriel C.; Cuthbert, Mark O.

    2018-04-01

    Clay-rich deposits are commonly assumed to be aquitards which act as natural hydraulic barriers due to their low hydraulic connectivity. Postdepositional weathering processes are known to increase the permeability of aquitards in the near surface but not impact on deeper parts of relatively thick formations. However, syndepositional processes affecting the hydraulic properties of aquitards have previously received little attention in the literature. Here, we analyze a 31 m deep sediment core recovered from an inland clay-rich sedimentary sequence using a combination of techniques including particle size distribution and microscopy, centrifuge dye tracer testing and micro X-ray CT imaging. Subaerial deposition of soils within these fine grained alluvial deposits has led to the preservation of considerable macropores (root channels or animal burrows). Connected pores and macropores thus account for vertical hydraulic conductivity (K) of 4.2×10-9 m/s (geometric mean of 13 samples) throughout the thick aquitard, compared to a matrix K that is likely sediment was deposited must be considered when aquitards are investigated as potential natural hydraulic barriers and illustrate the value of combining multiple investigation techniques for characterizing clay-rich deposits.

  20. Phosphate-solubility and phosphatase activity in Gangetic alluvial soil as influenced by organophosphate insecticide residues.

    Science.gov (United States)

    Majumder, Shyam Prasad; Das, Amal Chandra

    2016-04-01

    An experiment was conducted under laboratory conditions to investigate the effect of four organophosphate insecticides, viz. monocrotophos, profenophos, quinalphos and triazophos at their field application rates (0.75, 1.0, 0.5 and 0.6 kg a.i.ha(-1), respectively), on the growth and activities of phosphate solubilizing microorganisms in relation to availability of insoluble phosphates in the Gangetic alluvial soil of West Bengal, India. The proliferation of phosphate solubilizing microorganisms was highly induced with profenophos (38.3%), while monocrotophos exerted maximum stimulation (20.8%) towards the solubility of insoluble phosphates in soil. The phosphatase activities of the soil (both acid phosphatase and alkaline phosphatase) were significantly increased due to the incorporation of the insecticides in general, and the augmentation was more pronounced with quinalphos (43.1%) followed by profenophos (27.6%) for acid phosphatase, and with monocrotophos (25.2%) followed by profenophos (16.1%) for alkaline phosphatase activity in soil. The total phosphorus was highly retained by triazophos (19.9%) followed by monocrotophos (16.5%), while incorporation of triazophos and quinalphos manifested greater availability of water soluble phosphorus in soil. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

    International Nuclear Information System (INIS)

    Wu Fuzhong; Yang Wanqin; Zhang Jian; Zhou Liqiang

    2010-01-01

    To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 ± 19.22 and 576.75 ± 40.55 μg cadmium per plant with 110.77 ± 12.68 and 202.54 ± 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

  2. Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

    Energy Technology Data Exchange (ETDEWEB)

    Wu Fuzhong [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Yang Wanqin, E-mail: scyangwq@163.com [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Zhang Jian; Zhou Liqiang [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China)

    2010-05-15

    To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 {+-} 19.22 and 576.75 {+-} 40.55 {mu}g cadmium per plant with 110.77 {+-} 12.68 and 202.54 {+-} 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

  3. Perceptions of branded and plain cigarette packaging among Mexican youth.

    Science.gov (United States)

    Mutti, Seema; Hammond, David; Reid, Jessica L; White, Christine M; Thrasher, James F

    2017-08-01

    Plain cigarette packaging, which seeks to remove all brand imagery and standardize the shape and size of cigarette packs, represents a novel policy measure to reduce the appeal of cigarettes. Plain packaging has been studied primarily in high-income countries like Australia and the UK. It is unknown whether the effects of plain packaging may differ in low-and-middle income countries with a shorter history of tobacco regulation, such as Mexico. An experimental study was conducted in Mexico City to examine perceptions of branded and plain cigarette packaging among smoking and non-smoking Mexican adolescents (n = 359). Respondents were randomly assigned to a branded or plain pack condition and rated 12 cigarette packages for appeal, taste, harm to health and smoker-image traits. As a behavioral measure of appeal, respondents were offered (although not given) four cigarette packs (either branded or plain) and asked to select one to keep. The findings indicated that branded packs were perceived to be more appealing (β = 3.40, p packaging may reduce brand appeal among Mexican youth, consistent with findings in high-income countries. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Plain packaging of cigarettes: do we have sufficient evidence?

    Science.gov (United States)

    Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren

    2015-01-01

    Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. PMID:25897269

  5. International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain and for thromboplastin, recombinant, human, plain

    DEFF Research Database (Denmark)

    van den Besselaar, A M H P; Chantarangkul, V; Angeloni, F

    2018-01-01

    BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materia......) international standard (rTF/09). The candidate materials have been accepted by WHO as the 5(th) International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain. This article is protected by copyright. All rights reserved.......BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materials...... have been prepared. This report describes the calibration of the proposed 5(th) International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). METHODS: An international collaborative study was carried out for the assignment...

  6. The warming trend of ground surface temperature in the Choshui Alluvial Fan, western central Taiwan

    Science.gov (United States)

    Chen, W.; Chang, M.; Chen, J.; Lu, W.; Huang, C. C.; Wang, Y.

    2013-12-01

    Heat storage in subsurface of the continents forms a fundamental component of the global energy budget and plays an important role in the climate system. Several researches revealed that subsurface temperatures were being increased to 1.8-2.8°C higher in mean ground surface temperature (GST) for some Asian cities where are experiencing a rapid growth of population. Taiwan is a subtropic-tropic island with densely populated in the coastal plains surrounding its mountains. We investigate the subsurface temperature distribution and the borehole temperature-depth profiles by using groundwater monitoring wells in years 2000 and 2010. Our data show that the western central Taiwan plain also has been experiencing a warming trend but with a higher temperatures approximately 3-4 °C of GST during the last 250 yrs. We suggest that the warming were mostly due to the land change to urbanization and agriculture. The current GSTs from our wells are approximately 25.51-26.79 °C which are higher than the current surface air temperature (SAT) of 23.65 °C. Data from Taiwan's weather stations also show 1-1.5 °C higher for the GST than the SAT at neighboring stations. The earth surface heat balance data indicate that GST higher than SAT is reasonable. More researches are needed to evaluate the interaction of GST and SAT, and how a warming GST's impact to the SAT and the climate system of the Earth.

  7. PLAINS CO2 REDUCTION (PCOR) PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; Daniel J. Daly; Lynette L. de Silva; John A. Harju; Melanie D. Jensen; Erin M. O' Leary; Wesley D. Peck; Steven A. Smith; James A. Sorensen

    2006-01-01

    During the period of October 1, 2003, through September 30, 2005, the Plains CO2 Reduction (PCOR) Partnership, identified geologic and terrestrial candidates for near-term practical and environmentally sound carbon dioxide (CO2) sequestration demonstrations in the heartland of North America. The PCOR Partnership region covered nine states and three Canadian provinces. The validation test candidates were further vetted to ensure that they represented projects with (1) commercial potential and (2) a mix that would support future projects both dependent and independent of CO2 monetization. This report uses the findings contained in the PCOR Partnership's two dozen topical reports and half-dozen fact sheets as well as the capabilities of its geographic information system-based Decision Support System to provide a concise picture of the sequestration potential for both terrestrial and geologic sequestration in the PCOR Partnership region based on assessments of sources, sinks, regulations, deployment issues, transportation, and capture and separation. The report also includes concise action plans for deployment and public education and outreach as well as a brief overview of the structure, development, and capabilities of the PCOR Partnership. The PCOR Partnership is one of seven regional partnerships under Phase I of the U.S. Department of Energy National Energy Technology Laboratory's Regional Carbon Sequestration Partnership program. The PCOR Partnership, comprising 49 public and private sector members, is led by the Energy & Environmental Research Center at the University of North Dakota. The international PCOR Partnership region includes the Canadian provinces of Alberta, Saskatchewan, and Manitoba and the states of Montana (part), Wyoming (part), North Dakota, South Dakota, Nebraska, Missouri, Iowa, Minnesota, and Wisconsin.

  8. Plain packaging of cigarettes: do we have sufficient evidence?

    Directory of Open Access Journals (Sweden)

    Smith CN

    2015-04-01

    Full Text Available Collin N Smith,1 John D Kraemer,2 Andrea C Johnson,1 Darren Mays1 1Department of Oncology, Georgetown University Medical Center, Lombardi Comprehensive Cancer Center, Washington, DC, USA; 2Department of Health Systems Administration, School of Nursing and Health Studies, Georgetown University, Washington, DC, USA Abstract: Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. Keywords: cigarette smoking, tobacco, plain packaging, regulation, policy

  9. Late Quarternary evolution of the northern Hatteras Abyssal Plain

    International Nuclear Information System (INIS)

    Dickson, S.M.; Laine, E.P.

    1986-05-01

    The sedimentary history and seismic structure of a deep-water turbidite basin in the Western North Atlantic Ocean has been investigated to understand further the evolution of abyssal plains. This study integrates analyses of sedimentary and seismic facies in order to examine the temporal and spatial patterns of sedimentation on the northern Hatteras Abyssal Plain during the Late Quaternary. Forty deep-sea sediment cores and 6000 km of high resolution (3.5 kHz) seismic reflection profiles from within 31-34 0 N and 69-74 0 W include portions of the Hatteras Outer Ridge, Lower Continental Rise and Bermuda Rise as well as the northern Hatteras Abyssal Plain. Seismic profiles (within 32-33 0 N, 70-71.5 0 W) define two acoustically-transparent seismic units beneath the Plain. The composition of these seismic units has been investigated with sediment cores. This study has found two notable features in the sedimentary framework of the Plain that appear to have resulted from temporal changes in sediment supply. The most recent change, a postglacial decline in turbidity current activity, produced a diagenetic iron enrichment at the Pleistocene-Holocene boundary. The stratigraphic thickness affected by diagenesis is related spatially to patterns of turbidite sedimentation. An earlier change, discovered in this research, occurred during the Wisconsinian glaciation and brought coarser-grained turbidity currents to the northern Plain. Deposition of sands from these flows appears to have been locally controlled by a broad topographic feature with less than ten meters relief. As a result of the topographic influence, there are abrupt boundaries, both verically and laterally, between an older mud facies and a younger sandy turbidite facies of the Plain

  10. Biogeochemistry at a wetland sediment-alluvial aquifer interface in a landfill leachate plume

    Science.gov (United States)

    Lorah, M.M.; Cozzarelli, I.M.; Böhlke, J.K.

    2009-01-01

    The biogeochemistry at the interface between sediments in a seasonally ponded wetland (slough) and an alluvial aquifer contaminated with landfill leachate was investigated to evaluate factors that can effect natural attenuation of landfill leachate contaminants in areas of groundwater/surface-water interaction. The biogeochemistry at the wetland-alluvial aquifer interface differed greatly between dry and wet conditions. During dry conditions (low water table), vertically upward discharge was focused at the center of the slough from the fringe of a landfill-derived ammonium plume in the underlying aquifer, resulting in transport of relatively low concentrations of ammonium to the slough sediments with dilution and dispersion as the primary attenuation mechanism. In contrast, during wet conditions (high water table), leachate-contaminated groundwater discharged upward near the upgradient slough bank, where ammonium concentrations in the aquifer where high. Relatively high concentrations of ammonium and other leachate constituents also were transported laterally through the slough porewater to the downgradient bank in wet conditions. Concentrations of the leachate-associated constituents chloride, ammonium, non-volatile dissolved organic carbon, alkalinity, and ferrous iron more than doubled in the slough porewater on the upgradient bank during wet conditions. Chloride, non-volatile dissolved organic carbon (DOC), and bicarbonate acted conservatively during lateral transport in the aquifer and slough porewater, whereas ammonium and potassium were strongly attenuated. Nitrogen isotope variations in ammonium and the distribution of ammonium compared to other cations indicated that sorption was the primary attenuation mechanism for ammonium during lateral transport in the aquifer and the slough porewater. Ammonium attenuation was less efficient, however, in the slough porewater than in the aquifer and possibly occurred by a different sorption mechanism. A

  11. Yellowstone-Snake River Plain seismic profilling experiment: Crustal structure of the eastern Snake River Plain

    International Nuclear Information System (INIS)

    Braile, L.W.; Smith, R.B.; Ansorge, J.; Baker, M.R.; Sparlin, M.A.; Prodehl, C.; Schilly, M.M.; Healy, J.H.; Mueller, S.; Olsen, K.H.

    1982-01-01

    Seismic refraction profiles recorded along the eastern Snake River Plain (ESRP) in southeastern Idaho during the 1978 Yellowstone-Snake River Plain cooperative seismic profiling experiment are interpreted to infer the crustal velocity and attenuation (Q-1) structure of the ESRP. Travel-time and synthetic seismogram modeling of a 250 km reversed refraction profile as well as a 100 km detailed profile indicate that the crust of the ESRP is highly anomalous. Approximately 3 to 6 km of volcanic rocks (with some interbedded sediments) overlie an upper-crustal layer (compressional velocity approx. =6.1 km/s) which thins southwestward along the ESRP from a thickness of 10 km near Island Park Caldera to 2 to 3 km beneath the central and southwestern portions of the ESRP. An intermediate-velocity (approx. =6.5 km/s) layer extends from approx. =10 to approx. =20 km depth. a thick (approx. =22 km) lower crust of compressional velocity 6.8 km/s, a total crustall thickness of approx. =42 km, and a P/sub n/ velocity of approx. =7.9 km/s is observed in the ESRP, similar to the western Snake River Plain and the Rocky Mountains Provinces. High attenuation is evident on the amplitude corrected seismic data due to low-Q values in the volcanic rocks (Q/sub p/ = 20 to 200) and throughout the crust (Q/sub p/ = 160 to 300). Based on these characteristics of the crustal structure and volcanic-age progression data, it is suggested that the ESRP has resulted from an intensitive period of intrusion of mantle-derived basaltic magma into the upper crust generating explosive silicic volcanism and associated regional uplift and caldera collapse. This activity began about 15 m.y. ago in southwestern Idaho and has migrated northeast to its present position at Yellowstone. Subsequent cooling of the intruded upper crust results in the 6.5 km/s velocity intermediate layer. Crustal subsidence and periodic basaltic volcanism as represented by the ESRP complete the sequence of crustal evolution

  12. Organic manure of the corn (Zea mays L.) in alluvial soils of intermediate climate

    International Nuclear Information System (INIS)

    Tamayo V, Alvaro; Munoz A, Rodrigo; Diaz A; Carlos

    1997-01-01

    With the purpose to evaluate the effect on the yield of com ICA V.303 variety, using four sources of organic matter (hen manure, pig manure, cow manure, earthworm manure) in two doses (500 and 1.000 kg/ha), compared with a chemical treatment (300 kg/ha of 10-30-10 plus 150 kg of urea), and a control, an experiment was carried out at Tulio Ospina Research Center, located at Bello (Antioquia), with 1.320 m.s.n.m. The experiment was established using an alluvial soil (tropofluvent), frank, with low content of organic matter (3.1%), and potassium (0.11 meq/l00 g), and medium content of phosphorus (2 ppm). The results, after four consecutive harvests on the same plots, showed highly significative differences among treatments, compared with the control. The highest yield (4.709 kg/ha) was obtained with the chemical treatment (300 kg/ha of 10-30-10 plus 150 kg of urea). The addition of 500 and 1.000 kg/ha of hen manure and pig manure showed an average yield of corn of 4.315,4.539 .4.246, and 4.487 kg/ha respectively. the control only produced 2.620 kg/ha. The great profitability was obtained with 500 kg/ ha of cow manure, 1.000 kg/ha of pig manure and the chemical treatment (300 kg/ha 10-30-10 and 150 kg/ha of urea y 1.000 kg/ha hen manure). There were not significative differences between the chemical fertilization and the organic fertilization; these results show that organic matter is an alternative for fertilization with respect to the development of a sustained and biological agriculture

  13. Sensitivity Analysis of DRASTIC Model in Vulnerability Assessment of Shahrood Alluvial Aquifer

    Directory of Open Access Journals (Sweden)

    Shadi Abolhasan Almasi

    2017-07-01

    Full Text Available Groundwater vulnerability assessment is typically accomplished as a management tool to protect groundwater resources. In this research, the DRASTIC model which is an empirical one used for evaluating the potential of an aquifer for pollution was employed to evaluate the vulnerability of Shahrood alluvial aquifer. Moreover, the sensitivity of the model paramneters was assessed to identify the ones with greatest effect on vulnerability. The model layers including depth to groundwater table level, recharge, aquifer media, topography, impact of unsaturated zone, and hydraulic conductivity were prepared and classified in the ArcGIS software based on analyses of both the available data and the layer of surface soil texture using Aster satellite images. Once the vulnerability index was calculated, the sensitivity map of Shahroud aquifer vulnerability was analyzed using the two parameter removal and single parameter sensitivity methods. These were further verified by textural analysis of soil samples from different parts of the region. The layers with appropriate weights were overlaid and the DRASTIC index of the aquifer was estimated at 28 to 148. The highest vulnerability was detected in the northern margins and southwestern parts of the aquifer while other parts were characterized by medium to low vulnerability. The low nitrogen concentration observed in the farm areas and its rise to 45 mg/l in the northern stretches of the aquifer bear witness to the accuracy of the zoning rendered by the DRASTIC model. Based on the vulnerability map of Sharoud aquifer, it was found that 1.6% of the aquifer’s area has a very high vulnerability or potential for pollution followed by 10%, 28.8%, and 18.9% of the area were identified as having high, medium and low potentials for pollution, respecytively. The remaining (i.e., 40.5% was found to have no risk of pollution.

  14. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent

    2010-01-01

    Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

  15. Mapping groundwater renewability using age data in the Baiyang alluvial fan, NW China

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Li, Jie; Xiang, Yong; Zhao, Zhijiang

    2017-05-01

    Groundwater age has been used to map renewability of water resources within four groups: strong, partial, and rare renewability, and non-renewable. The Baiyang alluvial fan in NW China is a representative area for examining groundwater recharge from river infiltration and for mapping groundwater renewability, and it has been investigated using multiple isotopes and water chemistry. Systematic sampling included 52 samples for 2H and 18O analysis and 32 samples for 3H, 13C and 14C analysis. The δ13C compositions remain nearly constant throughout the basin (median -12.7‰) and indicate that carbonate dissolution does not alter 14C age. The initial 14C activity of 80 pmC, obtained by plotting 3H and 14C activity, was used to correct groundwater 14C age. The results show that areas closer to the river consist of younger groundwater ages; this suggests that river infiltration is the main recharge source to the shallow groundwater system. However, at distances far away from the river, groundwater ages become older, i.e., from modern water (less than 60 year) to pre-modern water (from 60 to 1,000 years) and paleowater (more than 1,000 yeas). The four classifications of groundwater renewability have been associated with different age ranges. The area of shallow groundwater with strong renewability accounts for 74% of the total study area. Because recharge condition (river infiltration) controls overall renewability, a groundwater renewability map is of significant importance to the management of groundwater exploitation of this area as well as other arid groundwater basins.

  16. Uranium-series comminution ages of continental sediments: Case study of a Pleistocene alluvial fan

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Victoria E.; DePaolo, Donald J.; Christensen, John N.

    2010-04-30

    Obtaining quantitative information about the timescales associated with sediment transport, storage, and deposition in continental settings is important but challenging. The uranium-series comminution age method potentially provides a universal approach for direct dating of Quaternary detrital sediments, and can also provide estimates of the sediment transport and storage timescales. (The word"comminution" means"to reduce to powder," reflecting the start of the comminution age clock as reduction of lithic parent material below a critical grain size threshold of ~;;50 mu m.) To test the comminution age method as a means to date continental sediments, we applied the method to drill-core samples of the glacially-derived Kings River Fan alluvial deposits in central California. Sediments from the 45 m core have independently-estimated depositional ages of up to ~;;800 ka, based on paleomagnetism and correlations to nearby dated sediments. We characterized sequentially-leached core samples (both bulk sediment and grain size separates) for U, Nd, and Sr isotopes, grain size, surface texture, and mineralogy. In accordance with the comminution age model, where 234U is partially lost from small sediment grains due to alpha recoil, we found that (234U/238U) activity ratios generally decrease with age, depth, and specific surface area, with depletions of up to 9percent relative to radioactive equilibrium. The resulting calculated comminution ages are reasonable, although they do not exactly match age estimates from previous studies and also depend on assumptions about 234U loss rates. The results indicate that the method may be a significant addition to the sparse set of available tools for dating detrital continental sediments, following further refinement. Improving the accuracy of the method requires more advanced models or measurements for both the recoil loss factor fa and weathering effects. We discuss several independent methods for obtaining fa on individual samples

  17. Colluvial and alluvial response to land use change in Midland England: An integrated geoarchaeological approach

    Science.gov (United States)

    Brown, Antony G.

    2009-07-01

    This paper presents geomorphic, soils and palaeoecological data from a small sub-catchment in the English Midlands in an attempt to provide an integrated picture of Holocene landscape change. The area used has also been the focus of a multi-disciplinary and long-term archaeological survey (Raunds Area Project) and so has a wealth of archaeological and historical data which can be related to the environmental record. The paper combines these data, much of which are only published in the archaeological literature with new interpretations based upon unpublished data and new data particularly from the hillslopes and new radiocarbon dating from the valley floor. It is inferred that despite a long history of pastoral and arable agriculture (since the Neolithic/Bronze Age), colluviation on lower slopes, significant soil redistribution and overbank alluviation only began to a measurable extent in the Late Saxon-Medieval period (9th Century AD onwards). It is suggested that this is due to a combination of land-use factors, principally the laying out of an intensive open field system and the establishment of villages combined with a period of extremes in climate well known throughout Europe. Indeed the critical element appears to have been the social changes in this period that created this regionally distinctive landscape which happened to have a high spatial connectivity and facilitated intensive arable production with high tillage rates. Intense rainfall events during this period could therefore detach and mobilize high volumes of soil and the open field system facilitated transport to slope bases and valley floors. The need for detailed and spatially precise land-use data in order to interpret accelerated landscape change is stressed.

  18. Spatial distribution of triazine residues in a shallow alluvial aquifer linked to groundwater residence time.

    Science.gov (United States)

    Sassine, Lara; Le Gal La Salle, Corinne; Khaska, Mahmoud; Verdoux, Patrick; Meffre, Patrick; Benfodda, Zohra; Roig, Benoît

    2017-03-01

    At present, some triazine herbicides occurrence in European groundwater, 13 years after their use ban in the European Union, remains of great concern and raises the question of their persistence in groundwater systems due to several factors such as storage and remobilization from soil and unsaturated zone, limited or absence of degradation, sorption in saturated zones, or to continuing illegal applications. In order to address this problem and to determine triazine distribution in the saturated zone, their occurrence is investigated in the light of the aquifer hydrodynamic on the basis of a geochemical approach using groundwater dating tracers ( 3 H/ 3 He). In this study, atrazine, simazine, terbuthylazine, deethylatrazine, deisopropylatrazine, and deethylterbuthylazine are measured in 66 samples collected between 2011 and 2013 from 21 sampling points, on the Vistrenque shallow alluvial aquifer (southern France), covered by a major agricultural land use. The frequencies of quantification range from 100 to 56 % for simazine and atrazine, respectively (LQ = 1 ng L -1 ). Total triazine concentrations vary between 15 and 350 ng L -1 and show three different patterns with depth below the water table: (1) low concentrations independent of depth but related to water origin, (2) an increase in concentrations with depth in the aquifer related to groundwater residence time and triazine use prior to their ban, and (3) relatively high concentrations at low depths in the saturated zone more likely related to a slow desorption of these compounds from the soil and unsaturated zone. The triazine attenuation rate varies between 0.3 for waters influenced by surface water infiltration and 4.8 for water showing longer residence times in the aquifer, suggesting an increase in these rates with water residence time in the saturated zone. Increasing triazine concentrations with depth is consistent with a significant decrease in the use of these pesticides for the last 10 years on

  19. Deposition and early hydrologic evolution of Westwater Canyon wet alluvial-fan system

    International Nuclear Information System (INIS)

    Galloway, W.E.

    1980-01-01

    The Westwater Canyon Member is one of several large, low-gradient alluvial fans that compose the Morrison Formation in the Four Corners area. Morrison fans were deposited by major laterally migrating streams entering a broad basin bounded by highlands to the west and south. The Westwater Canyon sand framework consists of a downfan succession of 1) proximal braided channel, 2) straight bed-load channel, 3) sinuous mixed-load channel, and 4) distributary mixed-load-channel sand bodies. Regional sand distribution and facies patterns are highly digitate and radiate from a point source located northwest of Gallup, New Mexico. Early ground-water flow evolution within the Westwater Canyon fan aquifer system can be inferred by analogy with Quaternary wet-fan deposits and by the interpreted paragenetic sequence of diagenetic features present. Syndepositional flow was controlled by the downfan hydrodynamic gradient and the high horizontal and vertical transmissivity of the sand-rich fan aquifer. Dissolution and transport of soluble humate would be likely in earliest ground water, which was abundant, fresh, and slightly alkaline. With increasing confinement of the aquifer below less permeable tuffaceous Brushy Basin deposits and release of soluble constituents from volcanic ash, flow patterns stabilized, and relatively more saline, uranium-rich ground water permeated the aquifer. Uranium mineralization occurred during this early postdepositional, semiconfined flow phase. Development of overlying Dakota swamps suggests a shallow water table indicative of regional dischare or stagnation. In either event, only limited downward flux of acidic water is recorded by local, bleached, kaolinized zones where the Westwater Canyon directly underlies the Dakota swamps. Subsequent ground-water flow phases have further obscured primary alteration patterns and caused local oxidation and redistribution of uranium

  20. New Module to Simulate Groundwater-Surface Water Interactions in Small-Scale Alluvial Aquifer System.

    Science.gov (United States)

    Flores, L.

    2017-12-01

    Streamflow depletion can occur when groundwater pumping wells lower water table elevations adjacent to a nearby stream. Being able to accurately model the severity of this process is of critical importance in semi-arid regions where groundwater-surface water interactions affect water rights and the sustainability of water resource practices. The finite-difference flow model MODFLOW is currently the standard for estimating groundwater-surface water interactions in many regions in the western United States. However, certain limitations of the model persist when highly-resolved spatial scales are used to represent the stream-aquifer system, e.g. when the size of computational grid cells is much less than the river width. In this study, an external module is developed and linked with MODFLOW that (1) allows for multiple computational grid cells over the width of the river; (2) computes streamflow and stream stage along the length of the river using the one-dimensional (1D) steady (over a stress period) shallow water equations, which allows for more accurate stream stages when normal flow cannot be assumed or a rating curve is not available; and (3) incorporates a process for computing streamflow loss when an unsaturated zone develops under the streambed. Use of the module not only provides highly-resolved estimates of streamflow depletion, but also of streambed hydraulic conductivity. The new module is applied to the stream-aquifer alluvial system along the South Platte River south of Denver, Colorado, with results tested against field-measured groundwater levels, streamflow, and streamflow depletion.

  1. Developing A New Predictive Dispersion Equation Based on Tidal Average (TA) Condition in Alluvial Estuaries

    Science.gov (United States)

    Anak Gisen, Jacqueline Isabella; Nijzink, Remko C.; Savenije, Hubert H. G.

    2014-05-01

    Dispersion mathematical representation of tidal mixing between sea water and fresh water in The definition of dispersion somehow remains unclear as it is not directly measurable. The role of dispersion is only meaningful if it is related to the appropriate temporal and spatial scale of mixing, which are identified as the tidal period, tidal excursion (longitudinal), width of estuary (lateral) and mixing depth (vertical). Moreover, the mixing pattern determines the salt intrusion length in an estuary. If a physically based description of the dispersion is defined, this would allow the analytical solution of the salt intrusion problem. The objective of this study is to develop a predictive equation for estimating the dispersion coefficient at tidal average (TA) condition, which can be applied in the salt intrusion model to predict the salinity profile for any estuary during different events. Utilizing available data of 72 measurements in 27 estuaries (including 6 recently studied estuaries in Malaysia), regressions analysis has been performed with various combinations of dimensionless parameters . The predictive dispersion equations have been developed for two different locations, at the mouth D0TA and at the inflection point D1TA (where the convergence length changes). Regressions have been carried out with two separated datasets: 1) more reliable data for calibration; and 2) less reliable data for validation. The combination of dimensionless ratios that give the best performance is selected as the final outcome which indicates that the dispersion coefficient is depending on the tidal excursion, tidal range, tidal velocity amplitude, friction and the Richardson Number. A limitation of the newly developed equation is that the friction is generally unknown. In order to compensate this problem, further analysis has been performed adopting the hydraulic model of Cai et. al. (2012) to estimate the friction and depth. Keywords: dispersion, alluvial estuaries, mixing, salt

  2. Uranium investigation in an alluvial aquifer with direct push methods - 59281

    International Nuclear Information System (INIS)

    De Weirdt, Fabian

    2012-01-01

    Document available in abstract form only. Full text of publication follows: The U.S. EPA has established a maximum contaminant level of 30 ug/l for uranium in drinking water due to its toxicity as a heavy metal. This regulation has affected many small public water supply systems in the US and several of them are struggling to come into compliance with the new standard. One such community is Clarks, NE, US which is situated on the alluvial deposits of the Platte River that are underlain by the Cretaceous Age Niobrara formation. Geoprobe Systems coordinated with the Nebraska Dept. of Health and Human Services, Water Well Stds. Program to investigate the cause of the elevated uranium in the groundwater that supplies drinking water to the village of Clarks. Initially hydraulic profiling tool (HPT) logs were obtained at selected locations across the Clarks well field. The HPT probe was advanced to depths of almost 36 m (120 ft) at several locations and the logs provided detailed information about the hydro-stratigraphy of the local aquifer not available from the drillers logs. The HPT logs were used to guide selection of screen depths for small diameter wells that were installed with direct push (DP) methods. A total of nine wells were installed at two locations at the facility with well depths ranging from as little as 6 m (20 ft) to a maximum of 36 m (118 ft). All wells were grouted bottom-up with a tremie tube using 25% solids bentonite slurry to assure screen interval isolation. (author)

  3. Advances in Field Deployable Instrumented Particles for the Study of Alluvial Transport Mechanisms

    Science.gov (United States)

    Dillon, B.; Strom, K.

    2017-12-01

    Advances in microelectromechanical systems (MEMs) in the past decade have lead to the development of various instrumented or "smart" particles for use in the study of alluvial transport. The goal of many of these devices is to collect data on the interaction between hydrodynamic turbulence and individual sediment particles. Studying this interaction provides a basis to better understand entrainment and deposition processes which leads to better predictive morphologic and transport models. In collecting data on these processes, researchers seek to capture the time history of the forces incident on the particle and the particle's reaction. Many methods have been employed to capture this data - miniaturized pressure traps, accelerometers, gyroscopes, MEMs pressure transducers, and cantilevered load cells. However no system to date has been able to capture the pressure forces incident on the particle and its reaction while remaining mobile and of a size and density comparable to most gravels. Advances in the development, deployment, and use of waterproofed laboratory instrumentation have led our research group to develop such a particle. This particle has been used in both laboratory settings and large-scale fluvial environments (coupled with a field-deployable PIV system) to capture data on turbulent erosion processes. This system advances the practice in several ways: 1) It is, at present, the smallest (⌀ 19mm) instrumented erodible particle reported in the literature. 2) It contains novel developments in pressure sensing technology which allow the inclusion of six pressure ports, a 3-axis accelerometer, and a 1-axis gyroscope - all of which can be recorded simultaneously. 3) It expands the researcher's abilities to gather data on phenomena that, previously, have mandated the use of a laboratory scale model. The use of this system has generated observations of the so-called very large scale motions (VLSMs) in a reach of the Virginia section of the New River. Their

  4. Habitat disturbance and hydrological parameters determine the body size and reproductive strategy of alluvial ground beetles.

    Science.gov (United States)

    Gerisch, Michael

    2011-01-01

    Environmental variability is the main driver for the variation of biological characteristics (life-history traits) of species. Therefore, life-history traits are particularly suited to identify mechanistic linkages between environmental variability and species occurrence and can help in explaining ecological patterns. For ground beetles, few studies directly related species traits to environmental variables. This study aims to analyse how life-history traits of alluvial ground beetles are controlled by environmental factors. I expected that the occurrence of species and the occurrence of specific traits are closely related to hydrological and disturbance parameters. Furthermore I expected most of the trait-variation to be explained by a combination of environmental variables, rather than by their isolated effects. Ground beetles were sampled in the year 2005 in floodplain grassland along the Elbe River in Germany. I used redundancy analysis to quantify the effects of hydrological, sediment, and disturbance related parameters on both species occurrence and species traits. I applied variation partitioning to analyse which environmental compartments explain most of the trait variation. Species occurrence and trait variation were both mainly controlled by hydrological and flood disturbance parameters. I could clearly identify reproductive traits and body size as key traits for floodplain ground beetles to cope with the environmental variability. Furthermore, combinations of hydrological, habitat disturbance, habitat type, and species diversity parameters, rather than their isolated effects, explained large parts of ground beetle trait variation. Thus, a main conclusion of this study is that ground beetle occurrence is mainly determined by complex, multi-scale interactions between environmental variability and their life-history traits.

  5. Unravelling the relative contribution of bed and suspended sediment load on a large alluvial river

    Science.gov (United States)

    Darby, S. E.; Hackney, C. R.; Parsons, D. R.; Leyland, J.; Aalto, R. E.; Nicholas, A. P.; Best, J.

    2017-12-01

    The world's largest rivers transport 19 billion tonnes of sediment to the coastal zone annually, often supporting large deltas that rely on this sediment load to maintain their elevation in the face of rising sea level, and to sustain high levels of agricultural productivity and biodiversity. However, the majority of estimates of sediment delivery to coastal regions pertain solely to the suspended fraction of the sediment load, with the bedload fraction often being neglected due to the difficulty in estimating bedload flux and the assumption that bedload contributes a minor (management plans, improved estimates of all fractions of the sediment load are essential. Recent advances in non-intrusive, high-resolution, technology have begun to enable more accurate estimates of bedload transport rates. However, the characterisation of the holistic sediment transport regime of large alluvial rivers is still lacking. Here, we develop a sediment transport rating curve, combining both suspended- and bed- load sediment fractions, for the Lower Mekong River. We define suspended sediment rating curves using the inversion of acoustic return data from a series of acoustic Doppler current profiler surveys conducted through the Lower Mekong River in Cambodia, and into the bifurcating channels of the Mekong delta in Vietnam. Additionally, we detail estimates of bed-load sediment transport determined using repeat multibeam echo sounder surveys of the channel bed. By combining estimates of both fractions of the sediment load, we show the spatial and temporal contribution of bedload to the total sediment load of the Mekong and refine estimates of sediment transport to the Mekong delta. Our results indicate that the time-averaged suspended load transport rates for the Mekong River are 87 MT/yr, whilst bedload transport forms c. management within this highly threatened river basin.

  6. Isotope investigation on groundwater recharge and dynamics in shallow and deep alluvial aquifers of southwest Punjab.

    Science.gov (United States)

    Keesari, Tirumalesh; Sharma, Diana A; Rishi, Madhuri S; Pant, Diksha; Mohokar, Hemant V; Jaryal, Ajay Kumar; Sinha, U K

    2017-11-01

    Groundwater samples collected from the alluvial aquifers of southwest Punjab, both shallow and deep zones were measured for environmental tritium ( 3 H) and stable isotopes ( 2 H and 18 O) to evaluate the source of recharge and aquifer dynamics. The shallow groundwater shows wide variation in isotopic signature (δ 18 O: -11.3 to -5.0‰) reflecting multiple sources of recharge. The average isotopic signature of shallow groundwaters (δ 18 O: -6.73 ± 1.03‰) is similar to that of local precipitation (-6.98 ± 1.66‰) indicating local precipitation contributes to a large extent compared to other sources. Other sources have isotopically distinct signatures due to either high altitude recharge (canal sources) or evaporative enrichment (irrigation return flow). Deep groundwater shows relatively depleted isotopic signature (δ 18 O: -8.6‰) and doesn't show any evaporation effect as compared to shallow zone indicating recharge from precipitation occurring at relatively higher altitudes. Environmental tritium indicates that both shallow ( 3 H: 5 - 10 T.U.) and deeper zone ( 3 H: 1.5 - 2.5 T.U.) groundwaters are modern. In general the inter-aquifer connections seem to be unlikely except a few places. Environmental isotope data suggests that shallow groundwater is dynamic, local and prone to changes in land use patterns while deep zone water is derived from distant sources, less dynamic and not impacted by surface manifestations. A conceptual groundwater flow diagram is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. General practitioners' willingness to request plain lumbar spine radiographic examinations

    International Nuclear Information System (INIS)

    Ryynaenen, Olli-Pekka; Lehtovirta, Jukka; Soimakallio, Seppo; Takala, Jorma

    2001-01-01

    Objectives: To examine general practitioners' attitudes to plain lumbar spine radiographic examinations. Design: A postal questionnaire consisting of questions on background data and doctors' opinions about plain lumbar spine radiographic examinations, as well as eight vignettes (imaginary patient cases) presenting indications for lumbar radiography, and five vignettes focusing on the doctors' willingness to request lumbar radiography on the basis of patients' age and duration of symptoms. The data were analysed according to the doctor's age, sex, workplace and the medical school of graduation. Setting: Finland. Subjects: Six hundred and fifteen randomly selected physicians working in primary health care (64% of original target group). Results: The vignettes revealed that the use of plain lumbar radiographic examination varied between 26 and 88%. Patient's age and radiation protection were the most prominent factors influencing doctors' decisions to request lumbar radiographies. Only slight differences were observed between the attitudes of male and female doctors, as well as between young and older doctors. Doctors' willingness to request lumbar radiographies increased with the patient's age in most vignettes. The duration of patients' symptoms had a dramatic effect on the doctor's decision: in all vignettes, doctors were more likely to request lumbar radiography when patient's symptoms had exceeded 4 weeks. Conclusions: General practitioners commonly use plain lumbar spine radiographic examinations, despite its limited value in the diagnosis of low back pain. Further consensus and medical education is needed to clarify the indications for plain lumbar radiographic examination

  8. Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania.

    Science.gov (United States)

    Miller, Kirk; Yost, Berwood; Abbott, Christina; Thompson, Scottie; Dlugi, Emily; Adams, Zachary; Schulman, Meryl; Strauss, Nicole

    2017-02-01

    We performed a health needs assessment for three Plain communities in Lancaster County, Pennsylvania from a random sample of households. Compared with the general population of adults, Plain respondents were more likely to be married, to have children, and they had large families; they were more likely to drink well water, to eat fruit and vegetables, to drink raw milk, and to live on a farm. Plain respondents had better physical and mental health and were less likely to have been diagnosed with various medical conditions compared with the general population of adults in Lancaster County but Old Order Mennonite respondents were more likely to have been diagnosed compared with Old Order Amish respondents. Plain respondents usually have a regular doctor and often receive preventive care but Old Order Mennonite respondents were more likely to have a regular doctor, to receive preventive care, to have had their children vaccinated, and to receive routine dental care compared with Old Order Amish respondents. Despite their relative geographic and genetic isolation, and despite the small, relative differences noted, the health of Plain communities in Lancaster County is similar to that of other adults in the County.

  9. Plain film diagnostic of the acromio-clavicular dislocation

    International Nuclear Information System (INIS)

    Vogel, H.; Thomae, J.; Jungbluth, K.H.; Hamburg Univ.

    1980-01-01

    The distance between the clavicula and the acromion, between the clavicula and the processus coracoideus and the step height between the acromion and the clavicula arch were measured on roentgen films. Evaluated were plain films of the shoulder and of the chest. 64 patients with dislocation of the acromio-clavicular joint were compared to patients without shoulder lesion. The comparance of both groups showed that measures exceeding the upper limits of the group without lesions are highly suggestive for acromio-clavicular dislocation. If one defines an acromio-clavicular dislocation as proved when two of the measured three distances exceed the upper limit, then an acromio-clavicular dislocation could be seen in 36% of the analysed cases on plain films of the shoulder and in 56% on plain chest films. (orig.) [de

  10. Tobacco branding, plain packaging, pictorial warnings, and symbolic consumption.

    Science.gov (United States)

    Hoek, Janet; Gendall, Philip; Gifford, Heather; Pirikahu, Gill; McCool, Judith; Pene, Gina; Edwards, Richard; Thomson, George

    2012-05-01

    We use brand association and symbolic consumption theory to explore how plain cigarette packaging would influence the identities young adults cocreate with tobacco products. Group discussions and in-depth interviews with 86 young adult smokers and nonsmokers investigated how participants perceive tobacco branding and plain cigarette packaging with larger health warnings. We examined the transcript data using thematic analysis and explored how removing tobacco branding and replacing this with larger warnings would affect the symbolic status of tobacco brands and their social connotations. Smokers used tobacco brand imagery to define their social attributes and standing, and their connection with specific groups. Plain cigarette packaging usurped this process by undermining aspirational connotations and exposing tobacco products as toxic. Replacing tobacco branding with larger health warnings diminishes the cachet brand insignia creates, weakens the social benefits brands confer on users, and represents a potentially powerful policy measure.

  11. Geomorphic Characterization of the FortyMile Wash Alluvial Fan, Nye County, Nevada, In Support of the Yucca Mountain Project

    International Nuclear Information System (INIS)

    Cline; De Long; Pelletier; Harrington

    2005-01-01

    In the event of an unlikely volcanic eruption through the proposed high-level radioactive waste repository at Yucca Mountain, contaminated ash would be deposited in portions of the Fortymile Wash drainage basin and would subsequently be redistributed to the Fortymile Wash alluvial fan by fluvial processes. As part of an effort to quantify the transport of contaminated ash throughout the fluvial system, characterization of the Fortymile Wash alluvial fan is required, especially the spatial distribution of fluvial activity over time scales of repository operation, and the rates of radionuclide migration into different soils on the fan. The Fortymile Wash alluvial fan consists of extremely low relief terraces as old as 70 ka. By conducting soils-geomorphic mapping and correlating relative surface ages with available geochronology from the Fortymile Wash fan and adjacent piedmonts, we identified 4 distinct surfaces on the fan. Surface ages are used to predict the relative stability of different areas of the fan to fluvial activity. Pleistocene-aged surfaces are assumed to be fluvially inactive over the 10 kyr time scale, for example. Our mapping and correlation provides a map of the depozone for contaminated ash that takes into account long-term channel migration the time scales of repository operation, and it provides a geomorphic framework for predicting radionuclide dispersion rates into different soils across the fan. The standard model for vertical migration of radionuclides in soil is diffusion; therefore we used diffusion profiles derived from 137 Cs fallout to determine infiltration rates on the various geomorphic surfaces. The results show a strong inverse correlation of the geomorphic surface age and diffusivity values inferred from the 137 Cs profiles collected on the different surfaces of the fan

  12. Determination of gold in Romanian auriferous alluvial sands and rocks by 14 MeV neutron activation analysis

    International Nuclear Information System (INIS)

    Lupu, Roxana; Nat, Alexandrina; Ene, Antoaneta

    2004-01-01

    In this work a complex study of the nuclear and spectral interferences which appear in gold determination by 14 MeV neutron activation analysis of Romanian auriferous alluvial sands and rocks has been accomplished. The contribution of the nuclear interfering elements - Hg and Pt - to the concentration of gold in the samples is minimum in the case of the nuclear reactions 197 Au(n, 2n) 196 Au, 197 Au (n,2n) 196m Au and 197 Au(n, n ' ) 197m Au. As regards the spectral interferences, these are minimum in the case of using the reactions 197 Au(n, n ' ) 197m Au and 197 Au (n, 2n) 196 Au and are due to Rb, Ti and V for the short irradiation and to Se for the long irradiation. We propose two methods of gold determination in auriferous alluvial sands and rocks in the range 20-2500 ppm - the minimum value of 20 ppm being at the level of an economic extraction - in the optima conditions established by us so that the systematic errors of analysis due to the gold accompanying elements should be considerably diminished: a method using short irradiation (25 s) and NaI(Tl) spectrometry for the measuring of the induced gamma radioactivity in the samples and a method using long irradiation (3000 s) and Ge(Li) spectrometry. The data presented in this paper can be adapted by other analysts to the rapid determination of gold in a variety of alluvial sands and rocks

  13. Assessing the impact of managed aquifer recharge on seasonal low flows in a semi-arid alluvial river

    Science.gov (United States)

    Ronayne, M. J.; Roudebush, J. A.; Stednick, J. D.

    2016-12-01

    Managed aquifer recharge (MAR) is one strategy that can be used to augment seasonal low flows in alluvial rivers. Successful implementation requires an understanding of spatio-temporal groundwater-surface water exchange. In this study we conducted numerical groundwater modeling to analyze the performance of an existing MAR system in the South Platte River Valley in northeastern Colorado (USA). The engineered system involves a spatial reallocation of water during the winter months; alluvial groundwater is extracted near the river and pumped to upgradient recharge ponds, with the intent of producing a delayed hydraulic response that increases the riparian zone water table (and therefore streamflow) during summer months. Higher flows during the summer are required to improve riverine habitat for threatened species in the Platte River. Modeling scenarios were constrained by surface (streamflow gaging) and subsurface (well data) measurements throughout the study area. We compare two scenarios to analyze the impact of MAR: a natural base case scenario and an active management scenario that includes groundwater pumping and managed recharge. Steady-periodic solutions are used to evaluate the long-term stabilized behavior of the stream-aquifer system with and without pumping/recharge. Streamflow routing is included in the model, which permits quantification of the timing and location of streamflow accretion (increased streamflow associated with MAR). An analysis framework utilizing capture concepts is developed to interpret seasonal changes in head-dependent flows to/from the aquifer, including groundwater-surface water exchange that impacts streamflow. Results demonstrate that accretion occurs during the target low-flow period but is not limited to those months, highlighting an inefficiency that is a function of the aquifer geometry and hydraulic properties. The results of this study offer guidance for other flow augmentation projects that rely on water storage in shallow

  14. Flood susceptibility assessment in a highly urbanized alluvial fan: the case study of Sala Consilina (southern Italy

    Directory of Open Access Journals (Sweden)

    N. Santangelo

    2011-10-01

    Full Text Available This paper deals with the risk assessment to alluvial fan flooding at the piedmont zone of carbonate massifs of the southern Apennines chain (southern Italy. These areas are prime spots for urban development and are generally considered to be safer than the valley floors. As a result, villages and towns have been built on alluvial fans which, during intense storms, may be affected by flooding and/or debris flow processes.

    The study area is located at the foothills of the Maddalena mountains, an elongated NW-SE trending ridge which bounds to the east the wide intermontane basin of Vallo di Diano. The area comprises a wide detrital talus (bajada made up by coalescent alluvial fans, ranging in age from the Middle Pleistocene to the Holocene. Historical analysis was carried out to ascertain the state of activity of the fans and to identify and map the zones most hit by past flooding. According to the information gathered, the Sala Consilina fans would appear prone to debris flows; in the past these processes have produced extensive damage and loss of life in the urban area. The watershed basins feeding the fans have very low response times and may produce debris flow events with high magnitudes. Taking into account the historical damage, the fan surface morphology, and the present urban development (street orientation and hydraulic network, the piedmont area was zoned and various susceptibility classes were detected. These results may represent a useful tool for studies aiming at territorial hazard mapping and civil protection interventions.

  15. The reevaluation of plain roentgenological study in isolated splenic injury

    International Nuclear Information System (INIS)

    Kang, Seong Ihn; Ko, Seung Sook; Kim, Kil Jeong; Oh, Jae Hee; Kim, Young Chul

    1986-01-01

    The spleen is the most common intraabdominal organ injured in blunt trauma. Although physical signs and symptoms, coupled with abdominal paracentesis and peritoneal lavage confirm intraabdominal injury, but isolated splenic injury especially delayed rupture, the diagnosis and clinical course is variable. We are reevaluation of plain roentgenologic findings for the light of early diagnosis of isolated splenic injury. 24 patients of the autopsy and surgically proven isolated splenic injury at Chosun University Hospital in the period from 1980 January to 1986 June were analyzed plain roentgenogram retrospectively. The results were as follows: 1. Male patients predominate, constitution 87.5%. Incidence has been greatest in second to fourth decade. 2. Mode of trauma causing isolated splenic injury is most common in motor vehicle accident and others are fall down, struck by fist, blow to object, uncertain blunt trauma. 3. Delayed rupture of spleen occurred in 2 cases (8.3%). 4. Common patterns of splenic injury is simple laceration that involves both the capsule and the parenchyma and a laceration that involves the splenic pedicle. 5. Plain chest roentgenographic findings were abnormal in 4 cases (16.7%). The most common plain abdominal roentgenographic findings was the evidence of intaabdominal fluid in 21 cases (87.5%). The others are included in order of frequency; gastric dilatation, prominent mucosal folds on greater curvature of the stomach, evidence of pelvic fluid, displacement of stomach to the right or downward, mass density in the region of spleen. 6. No relationship can be shown between patterns of injury, time lapse after trauma and plain roentgenological findings. But the evidence of intraabdominal fluid is most important in the light of early diagnosis. 7. Diagnosis of splenic injury may be most helpful that in combination with clinical history, clinical symptoms and signs and plain film findings. In delayed rupture, diagnostic value of serial examination

  16. The reevaluation of plain roentgenological study in isolated splenic injury

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seong Ihn; Ko, Seung Sook; Kim, Kil Jeong; Oh, Jae Hee; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    1986-10-15

    The spleen is the most common intraabdominal organ injured in blunt trauma. Although physical signs and symptoms, coupled with abdominal paracentesis and peritoneal lavage confirm intraabdominal injury, but isolated splenic injury especially delayed rupture, the diagnosis and clinical course is variable. We are reevaluation of plain roentgenologic findings for the light of early diagnosis of isolated splenic injury. 24 patients of the autopsy and surgically proven isolated splenic injury at Chosun University Hospital in the period from 1980 January to 1986 June were analyzed plain roentgenogram retrospectively. The results were as follows: 1. Male patients predominate, constitution 87.5%. Incidence has been greatest in second to fourth decade. 2. Mode of trauma causing isolated splenic injury is most common in motor vehicle accident and others are fall down, struck by fist, blow to object, uncertain blunt trauma. 3. Delayed rupture of spleen occurred in 2 cases (8.3%). 4. Common patterns of splenic injury is simple laceration that involves both the capsule and the parenchyma and a laceration that involves the splenic pedicle. 5. Plain chest roentgenographic findings were abnormal in 4 cases (16.7%). The most common plain abdominal roentgenographic findings was the evidence of intaabdominal fluid in 21 cases (87.5%). The others are included in order of frequency; gastric dilatation, prominent mucosal folds on greater curvature of the stomach, evidence of pelvic fluid, displacement of stomach to the right or downward, mass density in the region of spleen. 6. No relationship can be shown between patterns of injury, time lapse after trauma and plain roentgenological findings. But the evidence of intraabdominal fluid is most important in the light of early diagnosis. 7. Diagnosis of splenic injury may be most helpful that in combination with clinical history, clinical symptoms and signs and plain film findings. In delayed rupture, diagnostic value of serial examination

  17. Sources, lability and solubility of Pb in alluvial soils of the River Trent catchment, U.K

    International Nuclear Information System (INIS)

    Izquierdo, M.; Tye, A.M.; Chenery, S.R.

    2012-01-01

    Alluvial soils are reservoirs of metal contaminants such as Pb that originate from many different sources and are integrated temporally and spatially through erosional and depositional processes. In this study the source, lability and solubility of Pb were examined in a range of alluvial soils from the middle and lower River Trent and its tributary the River Dove using Pb isotope apportionment and isotopic dilution. All samples were collected within 10 m of the river bank to represent the soil that is most likely to be remobilised during bank erosion. Paired samples were taken from the topsoil (0–15 cm) and subsoil (35–50 cm) to assess differences with depth. Lead concentrations in soil ranged from 43 to 1282 mg/kg. The lability of soil Pb varied between 9 and 56% of total metal concentration whilst Pb concentrations in pore water varied between 0.2 and 6.5 μg/L. There was little difference in the % Pb lability between paired top and sub soils, possibly because soil characteristics such as pH, iron oxides and clay content were generally similar; a result of the recycling of eroded and deposited soils within the river system. Soil pH was found to be negatively correlated with % Pb lability. Source apportionment using 206 Pb/ 207 Pb and 208 Pb/ 207 Pb ratios showed that the isotopic ratios of Pb in the total, labile and solution pools fitted along a mixing line between Broken Hill Type (‘BHT’) Pb, used as an additive in UK petrol, and the local coal/Southern Pennine ore Pb. Various anomalies were found in the Pb isotopes of the bankside alluvial soils which were explained by point source pollution. Statistically significant differences were found between (i) the isotopic composition of Pb in the total soil pool and the labile/solution pools and (ii) the isotopic composition of Pb in the labile and solution pools, suggesting an enrichment of recent non-Pennine sources of Pb entering the soils in the labile and solution pools. -- Highlights: ► The labile

  18. Exploration for petroleum and natural gas in Sonai Plain

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, K

    1965-09-01

    Exploration in the Sonai Plain by Sekyu Shigen Kaihatsu Kabushiki Kaisha (Oil Resources Development Corporation) since 1955 is described. The development tasks are made difficult due to the presence of permeability traps. However, 41 out of 65 wells drilled up to late March of 1965 have been successful. Quantities of crude oil and natural gas produced in 1963 were, respectively, 5 and 6 times those of 1958. The Sonai Plain is a relatively new area, and there are still many unknown factors, yet the rate of development has increased greatly. More and deeper wells are expected to be drilled with even better results.

  19. Cultural Landscape and Tourism Potential in the Transylvanian Plain

    Directory of Open Access Journals (Sweden)

    WILFRIED SCHREIBER

    2007-01-01

    Full Text Available Contradicting the general belief that the Transylvanian Plain has a poor tourism potential, we bring proof that even in a non-tourist region there are many elements that can provide a generous support for a variety of tourism activities, such as: rural tourism, agro-tourism, recreational tourism, cultural and religious tourism, eco-tourism, and even the critical tourism may occur if the resources are not properly managed. Definitions, examples, two tables, and a map are offering additional information and data, in order to reveal a less known side of the Transylvanian Plain.

  20. Endeavor cruise 071 navigation and bathymetry, northern Hatteras Abyssal Plain

    International Nuclear Information System (INIS)

    Laine, E.P.; Friedrich, N.E.; McCreery, C.; Dickson, S.; Baker, M.

    1985-01-01

    Sub-bottom seismic profiling was carried out by R/V Endeavor during the summers of 1980 and 1981. Data collection was concentrated in LLWODP study area E-N3, which encompasses the northern Hatteras Abyssal Plain and the adjacent lower continental rise. Time, position, and depth were logged and marked on the seismic record at 15-minute intervals. These navigational and bathymetric data have been used to produce a time/position/depth listing, and a detailed bathymetric map of the northern Hatteras Abyssal Plain and surrounding physiographic provinces. 6 figures, 1 table

  1. Geoarchaeologic and paleopedologic evidences for the holocene paleoenvironmental evolution of the Crisuri plain (Western Romania

    Directory of Open Access Journals (Sweden)

    Nicolae Josan

    2007-12-01

    şuri (Fig. 2. Entre les rivières Crisul Repede et Crisul Negruest, les sites sont localisés le long d'une ligne nord-sud qui délimite un système de glacis et de terrasses développé au-dessus de 110 m d'altitude. On peut supposer que cette région a été préférée par les fermiers néolithiques à cause du réseau hydrographique stabilisé, de l'extension des surfaces planes relativement peu exposées aux inondations et de la présence de diverses ressources. Les vestiges laissés dans les sols par les activités humaines fournissent des informations sur les conditions paléoenvironnementales de la morphogenèse. De nombreux sites archéologiques de la Plaine de Crişuri sont susceptibles d'établir les caractéristiques du climat ancien : Girişu de Criş, Salca, Râpa (près de Tinca, Cefa, etc.Le site de Girişu de Criş est situé à l'extérieur du village du même nom, à 16 km à l'ouest d'Oradea, sur la rive droite de la rivière Crişul Repede. Un profil, ouvert jusqu'à 1,5 m de profondeur, met en évidence, à 30-40 cm de profondeur, la couche archéologique Basarabi (Hallstatt-C, 600-800 avant J.C.. C'est un horizon fortement argileux qui contient des bioaccumulations. Sous le premier horizon, à caractère humique, se trouve un horizon alluvial de couleur jaune (40-50 cm formé par des sables fins, qui recouvre à son tour un horizon de couleur noire (20-40 cm correspondant à un tchernoziom dans lequel ont été découverts des fragments de céramiques appartenant à la culture de Coţofeni (le commencement de l'Âge du Bronze. Sous ce dernier horizon se trouve le matériel parental formé par des argiles sableuses de couleur jaune (Fig. 3. La présence du sol noir contenant la culture Coţofeni (synchrone de la culture Pecel de Hongrie et Boden Retz d'Allemagne, datée de la période 3200-3500 avant J.C. correspond à la séquence pédologique spécifique de la stratigraphie de la plaine alluviale de l'Europe Centrale, qui a été d

  2. An Apparatus for Bed Material Sediment Extraction From Coarse River Beds in Large Alluvial Rivers

    Science.gov (United States)

    Singer, M. B.; Adam, H.; Cooper, J.; Cepello, S.

    2005-12-01

    Grain size distributions of bed material sediment in large alluvial rivers are required in applications ranging from habitat mapping, calibration of sediment transport models, high resolution sediment routing, and testing of existing theories of longitudinal and cross steam sediment sorting. However, characterizing bed material sediment from coarse river beds is hampered by difficulties in sediment extraction, a challenge that is generally circumvented via pebble counts on point bars, even though it is unclear whether the bulk grain size distribution of bed sediments is well represented by pebble counts on bars. We have developed and tested a boat-based sampling apparatus and methodology for extracting bulk sediment from a wide range of riverbed materials. It involves the use of a 0.4 x 0.4 x 0.2 meter stainless steel toothed sampler, called the Cooper Scooper, which is deployed from and dragged downstream by the weight of a jet boat. The design is based on that of a river anchor such that a rotating center bar connected to a rope line in the boat aligns the sampler in the downstream direction, the teeth penetrate the bed surface, and the sampler digs into the bed. The sampler is fitted with lead weights to keep it from tipping over. The force of the sampler `biting' into the bed can be felt on the rope line held by a person in the boat at which point they let out slack. The boat then motors to the spot above the embedded sampler, which is hoisted to the water surface via a system of pulleys. The Cooper Scooper is then clipped into a winch and boom assembly by which it is brought aboard. This apparatus improves upon commonly used clamshell dredge samplers, which are unable to penetrate coarse or mixed bed surfaces. The Cooper Scooper, by contrast, extracts statistically representative bed material sediment samples of up to 30 kilograms. Not surprisingly, the sampler does not perform well in very coarse or armored beds (e.g. where surface material size is on the

  3. Alluvial diamond resource potential and production capacity assessment of the Central African Republic

    Science.gov (United States)

    Chirico, Peter G.; Barthelemy, Francis; Ngbokoto, Francois A.

    2010-01-01

    In May of 2000, a meeting was convened in Kimberley, South Africa, and attended by representatives of the diamond industry and leaders of African governments to develop a certification process intended to assure that rough, exported diamonds were free of conflict concerns. This meeting was supported later in 2000 by the United Nations in a resolution adopted by the General Assembly. By 2002, the Kimberly Process Certification Scheme (KPCS) was ratified and signed by diamond-producing and diamond-importing countries. Over 70 countries were included as members of the KPCS at the end of 2007. To prevent trade in "conflict diamonds" while protecting legitimate trade, the KPCS requires that each country set up an internal system of controls to prevent conflict diamonds from entering any imported or exported shipments of rough diamonds. Every diamond or diamond shipment must be accompanied by a Kimberley Process (KP) certificate and be contained in tamper-proof packaging. The objective of this study was (1) to assess the naturally occurring endowment of diamonds in the Central African Republic (potential resources) based on geological evidence, previous studies, and recent field data and (2) to assess the diamond-production capacity and measure the intensity of mining activity. Several possible methods can be used to estimate the potential diamond resource. However, because there is generally a lack of sufficient and consistent data recording all diamond mining in the Central African Republic and because time to conduct fieldwork and accessibility to the diamond mining areas are limited, two different methodologies were used: the volume and grade approach and the content per kilometer approach. Estimates are that approximately 39,000,000 carats of alluvial diamonds remain in the eastern and western zones of the CAR combined. This amount is roughly twice the total amount of diamonds reportedly exported from the Central African Republic since 1931. Production capacity is

  4. Interactions between fauna and environment in recent alluvial soils (Dunajec River, SE Poland)

    Science.gov (United States)

    Mikuś, Paweł; Uchman, Alfred

    2017-04-01

    Recent riverine system is a particular place for interactions between fauna and the deposited sediments containing young and old alluvial soils. It is characterized by large energy gradients in relatively short time, which forces special adaptations of burrowing animals recorded in bioturbation structures. Predators produce mainly shelter burrows (interpreted as domichnia), and saprofags, especially earthworms, produce locomotion and feeding structures (pascichnia). Such structures have been studied in non- or poorly vegetated, sandy or muddy Holocene alluvia in the lower reach of the Dunajec River flowing through the Carpathian Foredeep in SE Poland. The observed burrows are mostly produced by a variety of organisms, including the European mole (Talpa europaea), common earthworm (Lumbricus terrestris), ground beetles (Carabidae), solitary bees (Ammophila), red fox (Vulpes vulpes), European beaver (Castor fiber), shrews (Soricidae), European otter (Lutra lutra), several species of mice (Muridae), voles (Myodae, Microtae), and the swallow sand martin (Riparia riparia). Burrows of a few species of ground beetles have been subjected to more detailed studies. Fertile deposits of older (early to middle Holocene) terraces, formed with many long-term interruptions in sedimentation processes, have a well-developed soil levels, more vulnerable to burrowing than recently deposited sediments. The terraces contain layers of sands and muds, which primary sedimentary structures and layer boundaries are completely or partly disturbed by bioturbation. Organic-rich muds have been moved up and down and mixed with sand. Moreover, sediments have been leached into open burrows during floods or rainfalls. In the natural levee sediments, mostly fine to medium sands, are horizontally burrowed, foremost by earthworms (Lumbricidae). Vertical, long (over 2 m deep) burrows of larger earthworms cross cut the natural levee sediments and enter buried soils. They were formed during a long period

  5. Probability distribution functions of turbulence in seepage-affected alluvial channel

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anurag; Kumar, Bimlesh, E-mail: anurag.sharma@iitg.ac.in, E-mail: bimk@iitg.ac.in [Department of Civil Engineering, Indian Institute of Technology Guwahati, 781039 (India)

    2017-02-15

    The present experimental study is carried out on the probability distribution functions (PDFs) of turbulent flow characteristics within near-bed-surface and away-from-bed surfaces for both no seepage and seepage flow. Laboratory experiments were conducted in the plane sand bed for no seepage (NS), 10% seepage (10%S) and 15% seepage (15%) cases. The experimental calculation of the PDFs of turbulent parameters such as Reynolds shear stress, velocity fluctuations, and bursting events is compared with theoretical expression obtained by Gram–Charlier (GC)-based exponential distribution. Experimental observations follow the computed PDF distributions for both no seepage and seepage cases. Jensen-Shannon divergence (JSD) method is used to measure the similarity between theoretical and experimental PDFs. The value of JSD for PDFs of velocity fluctuation lies between 0.0005 to 0.003 while the JSD value for PDFs of Reynolds shear stress varies between 0.001 to 0.006. Even with the application of seepage, the PDF distribution of bursting events, sweeps and ejections are well characterized by the exponential distribution of the GC series, except that a slight deflection of inward and outward interactions is observed which may be due to weaker events. The value of JSD for outward and inward interactions ranges from 0.0013 to 0.032, while the JSD value for sweep and ejection events varies between 0.0001 to 0.0025. The theoretical expression for the PDF of turbulent intensity is developed in the present study, which agrees well with the experimental observations and JSD lies between 0.007 and 0.015. The work presented is potentially applicable to the probability distribution of mobile-bed sediments in seepage-affected alluvial channels typically characterized by the various turbulent parameters. The purpose of PDF estimation from experimental data is that it provides a complete numerical description in the areas of turbulent flow either at a single or finite number of points

  6. Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

    Science.gov (United States)

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

    2014-01-01

    Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak (Quercus lyrata) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry (Celtis laevigata) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually

  7. Food Vulnerability and Alluvial Farming for Food Security in Central Dry Zone Area of Myanmar

    Science.gov (United States)

    Boori, M. S.; Choudhary, K.; Evers, M.; Kupriyanov, A.

    2017-10-01

    The central dry zone area of Myanmar is the most water stressed and also one of the most food insecure regions in the country. In the Dry Zone area, the total population is 10.1 million people in 54 townships, in which approximately 43 % live in below poverty line and 40-50 % of the rural population is landless. Agriculture is the most important economic sector in Myanmar as it is essential for national food security and a major source of livelihood for its people. In this region the adverse effects of climate change such as late or early onset of monsoon season, longer dry spells, erratic rainfall, increasing temperature, heavy rains, stronger typhoons, extreme spatial-temporal variability of rainfall, high intensities, limited rainfall events in the growing season, heat stress, drought, flooding, sea water intrusion, land degradation, desertification, deforestation and other natural disasters are believed to be a major constraint to food insecurity. For food vulnerability, we use following indicators: slope, precipitation, vegetation, soil, erosion, land degradation and harvest failure in ArcGIS software. The erosion is influenced by rainfall and slope, while land degradation is directly related to vegetation, drainage and soil. While harvest failure can be generate by rainfall and flood potential zones. Results show that around 45 % study area comes under very high erosion danger level, 70 % under average harvest failure, 59 % intermediate land degradation area and the overall around 45 % study area comes under insecure food vulnerability zone. Our analysis shows an increase in alluvial farming by 1745.33 km2 since 1988 to reduce the insecure food vulnerability. Food vulnerability map is also relevant to increased population and low income areas. The extreme climatic events are likely increase in frequency and magnitude of serious drought periods and extreme floods. Food insecurity is an important thing that must be reviewed because it relates to

  8. FOOD VULNERABILITY AND ALLUVIAL FARMING FOR FOOD SECURITY IN CENTRAL DRY ZONE AREA OF MYANMAR

    Directory of Open Access Journals (Sweden)

    M. S. Boori

    2017-10-01

    Full Text Available The central dry zone area of Myanmar is the most water stressed and also one of the most food insecure regions in the country. In the Dry Zone area, the total population is 10.1 million people in 54 townships, in which approximately 43 % live in below poverty line and 40–50 % of the rural population is landless. Agriculture is the most important economic sector in Myanmar as it is essential for national food security and a major source of livelihood for its people. In this region the adverse effects of climate change such as late or early onset of monsoon season, longer dry spells, erratic rainfall, increasing temperature, heavy rains, stronger typhoons, extreme spatial-temporal variability of rainfall, high intensities, limited rainfall events in the growing season, heat stress, drought, flooding, sea water intrusion, land degradation, desertification, deforestation and other natural disasters are believed to be a major constraint to food insecurity. For food vulnerability, we use following indicators: slope, precipitation, vegetation, soil, erosion, land degradation and harvest failure in ArcGIS software. The erosion is influenced by rainfall and slope, while land degradation is directly related to vegetation, drainage and soil. While harvest failure can be generate by rainfall and flood potential zones. Results show that around 45 % study area comes under very high erosion danger level, 70 % under average harvest failure, 59 % intermediate land degradation area and the overall around 45 % study area comes under insecure food vulnerability zone. Our analysis shows an increase in alluvial farming by 1745.33 km2 since 1988 to reduce the insecure food vulnerability. Food vulnerability map is also relevant to increased population and low income areas. The extreme climatic events are likely increase in frequency and magnitude of serious drought periods and extreme floods. Food insecurity is an important thing that must be reviewed

  9. Glacial vs. Interglacial Period Contrasts in Midlatitude Fluvial Systems, with Examples from Western Europe and the Texas Coastal Plain

    Science.gov (United States)

    Blum, M.

    2001-12-01

    Mixed bedrock-alluvial valleys are the conveyor belts for sediment delivery to passive continental margins. Mapping, stratigraphic and sedimentologic investigations, and development of geochronological frameworks for large midlatitude rivers of this type, in Western Europe and the Texas Coastal Plain, provide for evaluation of fluvial responses to climate change over the last glacial-interglacial period, and the foundations for future quantitative evaluation of long profile evolution, changes through time in flood magnitude, and changes in storage and flux of sediments. This paper focuses on two issues. First, glacial vs. interglacial period fluvial systems are fundamentally different in terms of channel geometry, depositional style, and patterns of sediment storage. Glacial-period systems were dominated by coarse-grained channel belts (braided channels in Europe, large-wavelength meandering in Texas), and lacked fine-grained flood-plain deposits, whereas Holocene units, especially those of late Holocene age, contain appreciable thicknesses of flood-plain facies. Hence, extreme overbank flooding was not significant during the long glacial period, most flood events were contained within bankfull channel perimeters, and fine sediments were bypassed through the system to marine basins. By contrast, extreme overbank floods have been increasingly important during the relatively short Holocene, and a significant volume of fine sediment is sequestered in flood-plain settings. Second, glacial vs. interglacial systems exhibit different amplitudes and frequencies of fluvial adjustment to climate change. High-amplitude but low-frequency adjustments characterized the long glacial period, with 2-3 extended periods of lateral migration and sediment storage puncuated by episodes of valley incision. Low-amplitude but high-frequency adjustments have been more typical of the short Holocene, when there has been little net valley incision or net changes in sediment storage, but

  10. Using dual isotopic data to track the sources and behaviors of dissolved sulfate in the western North China Plain

    International Nuclear Information System (INIS)

    Zhang, Dong; Li, Xiao-Dong; Zhao, Zhi-Qi; Liu, Cong-Qiang

    2015-01-01

    Highlights: • Dual sulfate isotopes were used to elucidate natural and anthropogenic sources in alluvial aquifers. • Infiltration, mixing and bacterial reduction were main processes controlling sulfate behaviors in groundwater. • Enrichment factors and ratio of sulfur and oxygen isotope of sulfate had been calculated. • Local sulfur cycles model had been establish for further management of groundwater. - Abstract: This paper investigated the sources and behaviors of sulfate in groundwater of the western North China Plain using sulfur and oxygen isotopic ratios. The groundwaters can be categorized into karst groundwater (KGW), coal mine drainage (CMD) and pore water (subsurface saturated water in interstices of unconsolidated sediment). Pore water in alluvial plain sediments could be further classified into unconfined groundwater (UGW) with depth of less than 30 m and confined groundwater (CGW) with depth of more than 60 m. The isotopic compositions of KGW varied from 9.3‰ to 11.3‰ for δ 34 S SO4 with the median value of 10.3‰ (n = 4) and 7.9‰ to 15.6‰ for δ 18 O SO4 with the median value of 14.3‰ (n = 4) respectively, indicating gypsum dissolution in karst aquifers. δ 34 S SO4 and δ 18 O SO4 values of sulfate in CMD ranged from 10.8‰ to 12.4‰ and 4.8‰ to 8.7‰ respectively. On the basis of groundwater flow path and geomorphological setting, the pore water samples were divided as three groups: (1) alluvial–proluvial fan (II 1 ) group with high sulfate concentration (median values of 2.37 mM and 1.95 mM for UGW and CGW, respectively) and positive δ 34 S SO4 and δ 18 O SO4 values (median values of 8.8‰ and 6.9‰ for UGW, 12.0‰ and 8.0‰ for CGW); (2) proluvial slope (II 2 ) group with low sulfate concentration (median values of 1.56 mM and 0.84 mM for UGW and CGW, respectively) and similar δ 34 S SO4 and δ 18 O SO4 values (median values of 9.0‰ and 7.4‰ for UGW, 10.2‰ and 7.7‰ for CGW); and (3) low-lying zone (II 3

  11. Comparison of groundwater recharge estimation techniques in an alluvial aquifer system with an intermittent/ephemeral stream (Queensland, Australia)

    Science.gov (United States)

    King, Adam C.; Raiber, Matthias; Cox, Malcolm E.; Cendón, Dioni I.

    2017-09-01

    This study demonstrates the importance of the conceptual hydrogeological model for the estimation of groundwater recharge rates in an alluvial system interconnected with an ephemeral or intermittent stream in south-east Queensland, Australia. The losing/gaining condition of these streams is typically subject to temporal and spatial variability, and knowledge of these hydrological processes is critical for the interpretation of recharge estimates. Recharge rate estimates of 76-182 mm/year were determined using the water budget method. The water budget method provides useful broad approximations of recharge and discharge fluxes. The chloride mass balance (CMB) method and the tritium method were used on 17 and 13 sites respectively, yielding recharge rates of 1-43 mm/year (CMB) and 4-553 mm/year (tritium method). However, the conceptual hydrogeological model confirms that the results from the CMB method at some sites are not applicable in this setting because of overland flow and channel leakage. The tritium method was appropriate here and could be applied to other alluvial systems, provided that channel leakage and diffuse infiltration of rainfall can be accurately estimated. The water-table fluctuation (WTF) method was also applied to data from 16 bores; recharge estimates ranged from 0 to 721 mm/year. The WTF method was not suitable where bank storage processes occurred.

  12. Characteristics of the gravel size and potassium in the Ejin Alluvial Fan from remote sensing images and stratigraphic section

    International Nuclear Information System (INIS)

    Zhang, Lu; Guo, Huadong; Wang, Qinjun

    2014-01-01

    The Ejin Alluvial Fan (EAF), located in the north-west of China, is an important recorder of both paleoclimatic and tectonic information of the north margin of the Qinghai-Tibet Plateau. Remote sensing technics, including optical and microwave sensors, have been the key spatial observation tools to extract the surface information related to the paleoenvironment. In this paper, the gravel size and chemical element potassium K distributions of the EAF were obtained from RadarSat-2 Synthetic Aperture Radar (SAR) data and LandSat TM optical data, respectively. In addition, the stratigraphic section of the EAF was established and the corresponding geological information in the vertical direction with different periods was obtained. Combining the geological survey information and surface distribution information, it can be concluded as follows. 1) The EAF covers an area of above 30,000 km 2 and may be the largest arid and semi-arid alluvial fan in the world based on the remote sensing survey. 2) Some surface parameters which are related to the paleoenvironmental change can be obtained from remote sensing data, such as the gravel size and potassium K parameters. 3) The forming process of the EAF and the corresponding environments will be understood deeply, combining the paleoenvironmental related parameters derived from remote sensing data and the geologic survey data

  13. Rapid determination of gold in Romanian auriferous alluvial sands, concentrates and rocks by 14 MeV NAA

    International Nuclear Information System (INIS)

    Nat, A.; Ene, A.; Lupu, R.

    2004-01-01

    The nuclear and spectral interferences in the 14 MeV neutron activation analysis (NAA) of gold from Romanian auriferous alluvial sands, concentrates and rocks have been studied and the optimum of activation, cooling and measuring times was determined for a maximum peak-to-background ratio for gold. The contribution of the nuclear interfering elements in the samples, Hg and Pt, to the concentration of gold has been calculated and, concluded that the nuclear reactions 197 Au(n,2n) 196 Au, 197 Au(n,2n) 196 mAu and 197 Au(n,n') 197 mAu can be used for gold determination, with minimal errors. Using the nuclear reactions 197 Au(n,n') 197 mAu and 197 Au(n,2n) 196 Au the spectral interferences are minimal and are due to Rb, Ti and V for a short irradiation and to Se for a long one. Two methods of fast gold determination were proposed for auriferous alluvial sands and rocks in the range of 20-2500 ppm, under the optimum conditions established so that the systematic errors of analysis due to the gold accompanying elements can be considerably diminished. For measuring the induced gamma-radioactivity in the samples either a short irradiation (25 seconds) with a NaI(Tl) detector or a long irradiation (3000 seconds) with a Ge(Li) detector were used. (author)

  14. Assessment of Intrinsic Vulnerability to Contamination for the Alluvial Aquifer in El-Fayoum Depression Using the Drastic Method

    International Nuclear Information System (INIS)

    Ahmed, M.A.

    2012-01-01

    Intrinsic vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. The vulnerability for the alluvial aquifer in El-Fayoum depression was assessed by applying the Drastic model as well as utilizing sensitivity analyses to evaluate the reliability of this model. This method uses seven parameters including climatic, geological, and hydrogeological conditions controlling the seepage of pollutant substances to groundwater. Vulnerability maps were produced by applying the Generic and Agricultural models according to the Drastic charter. The resulting agricultural Drastic vulnerability map indicates that 23.3%, 22.7% and 12.4% of El-Fayoum depression is under low, low-moderate and moderately high vulnerability of groundwater contamination, respectively, while 41.6% of the area of study can be designated as an area of moderate vulnerability of groundwater contamination. Resulting maps revealed that the potential for polluting groundwater with agricultural chemicals is greater than with Generic Drastic index pollutants. Depth to water table parameter inflicted the largest impact on the intrinsic vulnerability of the alluvial aquifer in El-Fayoum depression. Both the map removal and single-parameter sensitivity analyses indicated that the vulnerability index is the least sensitive to the removal of the recharge and hydraulic conductivity parameters but is highly sensitive to the removal of depth to water parameter.

  15. Reconnaissance investigation of the alluvial gold deposits in the North Takhar Area of Interest, Takhar Province, Afghanistan

    Science.gov (United States)

    Chirico, Peter G.; Malpeli, Katherine C.; Moran, Thomas W.

    2013-01-01

    This study is a reconnaissance assessment of the alluvial gold deposits of the North Takhar Area of Interest (AOI) in Takhar Province, Afghanistan. Soviet and Afghan geologists collected data and calculated the gold deposit reserves in Takhar Province in the 1970s, prior to the development of satellite-based remote-sensing platforms and new methods of geomorphic mapping. The purpose of this study was to integrate new mapping techniques with previously collected borehole sampling and concentration sampling data and geomorphologic interpretations to reassess the alluvial gold placer deposits in the North Takhar AOI. Through a combination of historical borehole and cross-section data and digital terrain modeling, the Samti, Nooraba-Khasar-Anjir, and Kocha River placer deposits were reassessed. Resource estimates were calculated to be 20,927 kilograms (kg) for Samti, 7,626 kg for Nooraba-Khasar-Anjir, 160 kg for the mouth of the Kocha, 1,047 kg for the lower Kocha, 113 kg for the middle Kocha, and 168 kg for the upper Kocha. Previous resource estimates conducted by the Soviets for the Samti and Nooraba-Khasar-Anjir deposits estimated 30,062 kg and 802 kg of gold, respectively. This difference between the new estimates and previous estimates results from the higher resolution geomorphic model and the interpretation of areas outside of the initial work zone studied by Soviet and Afghan geologists.

  16. Floods, Droughts and Farming on the Plains of Argentina and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-04-01

    Floods, Droughts and Farming on the Plains of Argentina and Paraguay, Pampas and Chaco Regions ... End Date. April 1, 2015 ... Argentina, South America, Paraguay, North and Central America ... IDRC is now accepting applications for this year's IDRC Doctoral Research Awards (IDRA). ... Careers · Contact Us · Site map.

  17. prediction of characteristics of coastal plain soils using terrain ...

    African Journals Online (AJOL)

    clay, electrical and hydraulic conductivity, bulk density, pH, exchangeable calcium, magnesium, sodium, potassium and acidity ... significantly correlated with clay and pH (H2O), while SPI and CTI correlated significantly with clay, pH, organic carbon and ... Key words: coastal plain sands, DEM, soil characteristics, modelling.

  18. Long-term Agroecosystem Research in the Northern Great Plains.

    Science.gov (United States)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  19. Finger millet: An alternative crop for the Southern High Plains

    Science.gov (United States)

    In the Southern High Plains, dairies are expanding to take advantage of favorable climatic conditions. Currently, corn (Zea mays L.) and forage sorghum [Sorghum bicolor (L.) Moench] are the two major crops grown in the region to meet silage demands for the expanding dairy industry, but they have rel...

  20. Removal of nanoparticles from plain and patterned surfaces using nanobubbles

    NARCIS (Netherlands)

    Yang, S.; Duisterwinkel, A.E.

    2011-01-01

    It is the aim of this paper to quantitatively characterize the capability of surface nanobubbles for surface cleaning, i.e., removal of nanodimensioned polystyrene particles from the surface. We adopt two types of substrates: plain and nanopatterned (trench/ridge) silicon wafer. The method used to

  1. The Education of Children in Pre-European Plains America.

    Science.gov (United States)

    Whitecap, Leah

    1988-01-01

    Describes child-rearing and educational practices of Plains Indians, stressing importance of hunting, especially of buffalo. Examines early childhood rituals and general child-rearing practices as part of cultural education. Describes religious education of children. Stresses Indian educational methods as "informal" but "direct and…

  2. Aerodynamic force coefficients of plain bridge cables in wet conditions

    DEFF Research Database (Denmark)

    Matteoni, Giulia; Georgakis, Christos T.

    In this paper, the aerodynamic forces and force coefficients from preliminary static wind tunnel tests on a plain cable in wet conditions are presented. The presented results are for several different relative cable wind-angles. A comparison is made with tests in dry conditions. In dry conditions...

  3. Sources and flow of north Canterbury Plains groundwater, New Zealand

    International Nuclear Information System (INIS)

    Taylor, C.B.; Brown, L.J.; Stewart, M.K.; Brailsford, G.W.; Wilson, D.D.; Burden, R.J.

    1989-01-01

    Geological, hydrological, isotope (tritium and 18 O) and chemical evidence is interpreted to give a mutually consistent picture of the recharge sources and flow patterns of the important groundwater resource in the deep Quaternary deposits of the Canterbury Plains between Selwyn R. and Ashley R. The study period for tritium measurements extends over 27 years, encompassing the peak and decline of thermonuclear tritium fallout in this region. Major rivers emerging from mountain catchments to the west of the Plains are depleted in 18 O relative to average low-level precipitation. Most of the groundwater is river-recharged, but some areas with significant local precipitation recharge are clearly identified by 18 O and chemical concentrations. Artesian groundwater underlying Christchurch ascends from deeper aquifers into the shallowest aquifer via gaps in the confining layers; much of this flow is induced by withdrawal. The Christchurch aquifers are recharged by infiltration from Waimakariri R. in its central Plains reaches, and the resulting flow regime is E- and SE-directed; satisfactory water quality of the deeper Christchurch aquifer appears to be guaranteed for the future provided the river can be maintained in its present condition. Shallow groundwater, and water recharged to depth by other rivers, irrigation and local precipitation on the unconfined western areas of the Plains, are more susceptible to agricultural and other pollutants; none of this water is encountered in the deeper aquifers under Christchurch. (author). 15 refs., 12 figs

  4. Introducing Plain Language Principles to Business Communication Students

    Science.gov (United States)

    Greer, Rachelle R.

    2012-01-01

    In response to current federal mandates requiring selected businesses and government agencies to use plain language (PL) when reporting information to the public, this article advocates the introduction of PL principles into current business communication curricula. Despite recent PL mandates and advances, many current business textbooks and…

  5. Wind Shear Characteristics at Central Plains Tall Towers (presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.; Elliott, D.

    2006-06-05

    The objectives of this report are: (1) Analyze wind shear characteristics at tall tower sites for diverse areas in the central plains (Texas to North Dakota)--Turbines hub heights are now 70-100 m above ground and Wind measurements at 70-100+ m have been rare. (2) Present conclusions about wind shear characteristics for prime wind energy development regions.

  6. Computations Of Critical Depth In Rivers With Flood Plains | Okoli ...

    African Journals Online (AJOL)

    Critical flows may occur at more than one depth in rivers with flood plains. The possibility of multiple critical depths affects the water-surface profile calculations. Presently available algorithms determine only one of the critical depths which may lead to large errors. It is the purpose of this paper to present an analytical ...

  7. Diagnostic value of plain abdominal radiographs in acute ...

    African Journals Online (AJOL)

    Objective: The plain film of the abdomen (PAX) is still utilised in the diagnosis of acute appendicitis (Aap). Aim of this study was to evaluate the value of PAX in the diagnosis of Aap in children, since it continues to be a controversial subject. Design: A retrospective study. Setting: Department of Paediatric Surgery, Gazi ...

  8. Tear Gas, Expanding Bullets and Plain-Clothed Personnel

    DEFF Research Database (Denmark)

    Wiesener, Cornelius Rust

    2017-01-01

    This article examines the interplay between human rights law and humanitarian law in relation to riot control agents (such as tear gas), expanding bullets and plain-clothed forces. While outlawed under humanitarian law, they are widely used by police in peace time and not subject to similar bans...

  9. Clinical aspects of plain film radiography of the chest

    International Nuclear Information System (INIS)

    Ravin, C.E.

    1988-01-01

    In spite of the introduction of a number of intriguing new imaging modalities including Computed Tomography and Magnetic Resonance Imaging, the plain film of the chest remains the mainstay of thoracic imaging. It is estimated that more than fifty million chest radiographs are performed each year in the United States. In the attempt to compare newer imaging modalities with the standard plain film of the chest, investigators have been forced to adopt specific structures and or disease processes to be analyzed. To some extent identification of normally appearing structures in the mediastinum and lung parenchyma serves as a clue as to the ability of a newer technology to compete with or be compared with the plain film. However, as most authors would acknowledge, the ability to portray normal underlying anatomy is only the first step in analysis in intrathoracic disease. Experimental design becomes somewhat more complicated when one wishes to move beyond normal anatomy to analysis of disease processes. The challenge of digital radiography in whatever form it may take will be to equal or exceed the standard established by conventional plain film radiography and deliver such service at reasonable cost in a manner which allows for appropriate patient throughput

  10. Destruction of the arid plains by tubing in Kalmykia

    Directory of Open Access Journals (Sweden)

    V. P. Chichagov

    2006-01-01

    Full Text Available The expedition researches results of natural state after functioning of the water and oil extraction tubes on the territory of Kalmykia republic. It’s shown that any linear destroyment of the North-West Caspian plain makes complex activity of exogenic processes, main of which are: erosion, suffusion and deflation.

  11. Plain ABDO X-rays: a waste of time?

    Science.gov (United States)

    2002-03-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study, 131 plain abdominal radiographs performed on the day of admission were prospectively analysed by the research team. In only 16 cases (12 per cent) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47 per cent), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24 per cent). The clinical management was influenced by plain abdominal radiographs in only nine cases (7 per cent). The researchers argue that most plain abdominal radiographs requested on acute medical emergencies are inappropriate. They suggest there is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

  12. Guesstimation of posterior malleolar fractures on lateral plain radiographs

    NARCIS (Netherlands)

    Meijer, D. T.; Doornberg, J. N.; Sierevelt, I. N.; Mallee, W. H.; van Dijk, C. N.; Kerkhoffs, G. M.; Stufkens, S. A.; Palmanovich, Ezequiel; van Sterkenburg, Maayke; Engvall, Andreas; Arroyo, Ernesto; Golovakha, Maksym; Pereira, Ernesto; Josep Torrent, Eugene Toh; Haverkamp, Daniel; Bojanic, Ivan; Sousa, Manuel; Aragon, Oscar Castro; Russo, Alessandro; Cortes, Carlos; Pánics, Gergely; Vide, João; Spanos, Loannis; Carvalho, Manuel Santos; Maggi, Pablo; Thomas, Zach; Tanaka, Hirofumi; Dinato, Mauro; Fay, Jakob; Kimtys, Vytautas; Correia Moreira, António José; Hatziemmanuil, Dimitrios; Low, Tze-Choong; van der Plaat, Laurens Wessel; Mora, Allan David; van Rensen, Inge; del Vecchio, Javier; Ramos, James; Azevedo, Jorge; Bustamante, Carlos; Oliveira, Alexandre; Zaw, Htwe; Kurup, Harish; Yli-Kyyny, Tero; Baca, Emre; Haapasalo, Heidi; Bakhtamyan, Gurgen; Zbikowski, Piotr; van den Bekerom, Michel; de Muinck Keizer, Robert-Jan

    2015-01-01

    Accurate assessment of articular involvement of the posterior malleolar fracture fragments in ankle fractures is essential, as this is the leading argument for internal fixation. The purpose of this study is to assess diagnostic accuracy of measurements on plain lateral radiographs. Quantification

  13. Holocene climatic fluctuations from Lower Brahmaputra flood plain

    Indian Academy of Sciences (India)

    Pollen analysis of a 3.2-m deep sedimentary profile cored from the Dabaka Swamp, Nagaon District, Lower Brahmaputra flood plain, Assam has revealed persistent fluvial activity during 14,120–12,700 cal years BP which may be attributed to the paucity of pollen and spores with encounterance of fluvial marker taxa like ...

  14. The case for the plain packaging of tobacco products.

    Science.gov (United States)

    Freeman, Becky; Chapman, Simon; Rimmer, Matthew

    2008-04-01

    The Framework Convention on Tobacco Control (FCTC) requires nations that have ratified the convention to ban all tobacco advertising and promotion. In the face of these restrictions, tobacco packaging has become the key promotional vehicle for the tobacco industry to interest smokers and potential smokers in tobacco products. This paper reviews available research into the probable impact of mandatory plain packaging and internal tobacco industry statements about the importance of packs as promotional vehicles. It critiques legal objections raised by the industry about plain packaging violating laws and international trade agreements. Searches for available evidence were conducted within the internal tobacco industry documents through the online document archives; tobacco industry trade publications; research literature through the Medline and Business Source Premier databases; and grey literature including government documents, research reports and non-governmental organization papers via the Google internet search engine. Plain packaging of all tobacco products would remove a key remaining means for the industry to promote its products to billions of the world's smokers and future smokers. Governments have required large surface areas of tobacco packs to be used exclusively for health warnings without legal impediment or need to compensate tobacco companies. Requiring plain packaging is consistent with the intention to ban all tobacco promotions. There is no impediment in the FCTC to interpreting tobacco advertising and promotion to include tobacco packs.

  15. Prediction of characteristics of coastal plain soils using terrain ...

    African Journals Online (AJOL)

    The objective of this study was to model the characteristics of coastal plain sands using terrain attributes. Representative surface soil samples of upper, middle and lower slopes were collected from 10 locations and their properties determined using standard laboratory methods. Soil properties determined include depth, ...

  16. Visualizing Gender Variability in Plains Indian Pictographic Art

    Science.gov (United States)

    Carocci, Max

    2009-01-01

    This article analyzes the few published references to gender variation among Plains Indians in order to contribute to a growing corpus of literature concerned with building a more complete picture of the social and cultural lives of individuals accustomed to these practices. In recent years these people have been known among Native Americans under…

  17. Traditional Plains Indian Art and the Contemporary Indian Student.

    Science.gov (United States)

    Pakes, Fraser

    1987-01-01

    Examines underlying concepts in traditional Plains Indian arts and encourages incorporation of traditional concepts into contemporary art education. Discusses spiritual foundations, holism, art for art's sake, portability, body art, conservation, tribal identity, aesthetic features, age/sex differentiation in art production, white society's…

  18. Coastal plain community tree guide: benefits, costs, and strategic planning

    Science.gov (United States)

    E. Gregory McPherson; James R. Simpson; Paula J. Peper; Shelley L. Gardner; Kelaine E. Vargas; Scott E. Maco; Qingfu Xiao

    2006-01-01

    This report quantifies benefits and costs for representative large, medium, and small broadleaf trees and coniferous trees in the Coastal Plain region: the species chosen as representative are the Southern live oak (Quercus virginiana), Southern magnolia (Magnolia grandiflora), flowering dogwood (Cornus florida...

  19. Ball Games of Native American Women of the Plains.

    Science.gov (United States)

    Pesavento, Wilma J.

    The problem under investigation concerned (1) determining the ball games of Native American girls and women of the Great Plains, (2) determining the geographical spread of the games within the culture area, and (3) determining the characteristics of the various games. Data for this investigation were obtained from the 48 "Annual Reports of the…

  20. Terrain And Laboratory Conductivity Studies Of Flood Plains Of ...

    African Journals Online (AJOL)

    A shallow electromagnetic study (electrical conductivity and magnetic susceptibility measurements) and laboratory conductivity sampling of the flood plains of Oluwatuyi/Oshinle area of Akure have been undertaken. This is with the aim of correlating the terrain conductivity mapping with laboratory measurements to establish ...

  1. Astrobiology and the Basaltic Plains in Gusev Crater

    Science.gov (United States)

    DesMarais, D. J.; Clark, B. C.; Crumpler, L. S.; Farmer, J. D.; Grotzinger, John P.; Haskin, Larry A.; Knoll, Andrew H.; Landis, Geoffrey A.; Moersch, Jeffrey; Schroeder, Christian

    2005-01-01

    This report assesses the availability of nutrient elements, energy and liquid water on the plains surrounding Columbia Memorial Station by evaluating observations by the MER rover Spirit in the context of previous Mars missions, Earth-based studies of martian meteorites and studies of microbial communities on Earth that represent potential analogs of martian biota.

  2. PLAINS GERBILS (GERBILLISCUS ROBUSTA) AS FOOD OF THE ...

    African Journals Online (AJOL)

    Mgina

    Skull and other bone contents were mostly (about 90%) of Gerbilliscus robusta, suggesting this rodent to still be an important food item of the barn owl in the ... Their biology and ecology on the plains have received but few studies (Senzota 1990, Reed 2011). Gerbils are ground dwelling rodents that have also been tamed ...

  3. Dendroclimatic potential of plains cottonwood (Populus deltoides subsp. monilifera) from the Northern Great Plains, USA

    Science.gov (United States)

    Edmonson, Jesse; Friedman, Jonathan; Meko, David; Touchan, Ramzi; Scott, Julian; Edmonson, Alan

    2014-01-01

    A new 368-year tree-ring chronology (A.D. 1643–2010) has been developed in western North Dakota using plains cottonwood (Populus deltoides subsp. monilifera) growing on the relatively undisturbed floodplain of the Little Missouri River in the North Unit of Theodore Roosevelt National Park. We document many slow-growing living trees between 150–370 years old that contradict the common understanding that cottonwoods grow fast and die young. In this northern location, cottonwood produces distinct annual rings with dramatic interannual variability that strongly crossdate. The detrended tree-ring chronology is significantly positively correlated with local growing season precipitation and soil moisture conditions (r  =  0.69). This time series shows periods of prolonged low radial tree growth during the known droughts of the instrumental record (e.g. 1931–1939 and 1980–1981) and also during prehistory (e.g. 1816–1823 and 1856–1865) when other paleoclimate studies have documented droughts in this region. Tree rings of cottonwood will be a useful tool to help reconstruct climate, streamflow, and the floodplain history of the Little Missouri River and other northern river systems.

  4. LAND SUITABILITY SCENARIOS FOR ARID COASTAL PLAINS USING GIS MODELING: SOUTHWESTERN SINAI COASTAL PLAIN, EGYPT

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Wahid

    2009-12-01

    Full Text Available Site selection analysis was carried out to find the best suitable lands for development activities in an example of promising coastal plains, southwestern Sinai, Egypt. Two GIS models were developed to represent two scenarios of land use suitability in the study area using GIS Multi Criteria Analysis Modeling. The factors contributed in the analysis are the Topography, Land cover, Existing Land use, Flash flood index, Drainage lines and Water points. The first scenario was to classify the area according to various gradual ranges of suitability. According to this scenario, the area is classified into five classes of suitability. The percentage of suitability values are 51.16, 6.13, 22.32, 18.49 and 1.89% for unsuitable, least suitable, low suitable, suitable and high suitable, respectively. The second scenario is developed for a particular kind of land use planning; tourism and recreation projects. The suitability map of this scenario was classified into five values. Unsuitable areas represent 51.18% of the study area, least suitable 16.67%, low suitable 22.85%, suitable 8.61%, and high suitable 0.68%. The best area for locating development projects is the area surrounding El-Tor City and close to the coast. This area could be an urban extension of El-Tor City with more economical and environmental management.

  5. 78 FR 17653 - Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408)

    Science.gov (United States)

    2013-03-22

    ... Wildlife Service Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS... Plains Wind Energy Draft Programmatic Environmental Impact Statement (Draft [[Page 17654

  6. Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma

    Science.gov (United States)

    Ryter, Derek W.; Correll, Jessica S.

    2016-01-14

    This report describes a study of the hydrology, hydrogeological framework, numerical groundwater-flow models, and results of simulations of the effects of water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma. The purpose of the study was to provide analyses, including estimating equal-proportionate-share (EPS) groundwater-pumping rates and the effects of projected water use and droughts, pertinent to water management of the Beaver-North Canadian River alluvial aquifer for the Oklahoma Water Resources Board.

  7. Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Science.gov (United States)

    Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  8. 41 CFR 102-2.140 - What elements of plain language appear in the FMR?

    Science.gov (United States)

    2010-07-01

    ... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What elements of plain language appear in the FMR? 102-2.140 Section 102-2.140 Public Contracts and Property Management Federal...

  9. Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Science.gov (United States)

    Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  10. Formation mechanism of land subsidence in the North China Plain

    Science.gov (United States)

    Guo, Haipeng; Cheng, Guoming

    2014-05-01

    Land subsidence is a progressive and gradual geological disaster, whose development is irreversible. Due to rapid development of industrialization and urbanization, land subsidence occurs commonly in the North China Plain, and has become the main environmental factor impacting sustainable economic and social development. This study presents a brief review on the current situation of land subsidence in the North China Plain. Then the hydrologic, hydrogeologic and anthropogenic conditions favorable for the formation of land subsidence are analyzed, indicating that the formation of land subsidence is mainly determined by local geological condition and enabling conditions, e.g. long-term excessive exploitation of groundwater and engineering construction. A correlation analysis was conducted in both the North China Plain and Cangzhou region, a typical area where severe land subsidence occurs, of the quantitative relationship between deep groundwater yield and the land subsidence. The analysis results indicate that the land subsidence volume accounts for 40% to 44% of deep water yield in the North China Plain, indirectly showing the proportion of released water from compressibility of the aquifer and the aquitard in deep groundwater yield. In Cangzhou region, this proportion was calculated as 58%, far greater than that of the North China Plain. This is induced by the local lithologic structure and recharge condition of deep groundwater in Cangzhou region. The analysis of soil samples in Cangzhou region shows that strong relations exist among different physical parameters, and good change laws of compression with depth and pressure are found for soil samples. The hydraulic conductivities of clay are six orders of magnitude greater than those of the aquifer, implying the strong hypothesis of land subsidence. This analysis provides data and scientific basis for further study on formation mechanism of land subsidence in Cangzhou region and objective evaluation of its

  11. Intussusception in childhood: the role of plain abdominal radiographs

    International Nuclear Information System (INIS)

    Ji, Joo Yun; Kim, Min Joong; Kim, Young Mook; Park, Won Gyu; Ko, Kang Seok; Kim, Se Jong; Park, Byung Ran; Kim, Byong Geun

    1995-01-01

    The purposes of this study were to evaluate the plain radiologic findings of the childhood intussusception and to evaluate the role of plain abdominal films in predicting the success of air or barium reduction. We retrospectively reviewed 140 cases with the diagnosis of intussusception in childhood. The radiological signs that included soft tissue mass, dilatation of small bowel suggesting obstruction, crescent sign, and target sign were evaluated in terms of frequency. The relationship between radiological findings and outcome of reduction was analyzed. The site of soft tissue mass or crescent sign seen on plain radiographs was correlated with the position of the apex of the intussusceptum seen at the beginning of barium edema. The degree of dilated small bowel was evaluated by calculating the proportion of air-filled small bowel occupying peritoneal cavity and measuring the maximal diameter of dilated bowel lumen. The radiological finding for small bowel obstruction is determined by observation of the degree of small bowel dilatation and/or air-fluid levels. Ninety-two cases out of 140 showed one or more radiographic signs. Two most common signs were soft tissue mass and small bowel obstruction. The success rate of air or barium reduction was significantly lower in patients with most severe degree of dilatation of small bowel and/or more than 7 air-fluid levels on erect view. The suspected location of intussusception on plain radiographs correlated well with the true location of intussusception seen in the first few seconds of barium reduction. Plain abdominal radiography is useful in the diagnosis of intussusception and provides helpful information for the reduction procedure as well as for the exclusion of the contraindications such as bowel perforation

  12. Acute paediatric ankle trauma: MRI versus plain radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lohman, M. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Radiological Dept., Helsinki University Central Hospital (Finland); Kivisaari, A.; Kivisaari, L. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Kallio, P.; Puntila, J. [Dept. of Paediatric Surgery, Hospital for Children and Adolescents, Helsinki Univ. Central Hospital, Helsinki (Finland); Vehmas, T. [Finnish Institute of Occupational Health, Helsinki (Finland)

    2001-09-01

    Objective: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. Methods: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three ''masked'' radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. Results: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures. Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter- Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. Conclusions: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries. (orig.)

  13. Acute paediatric ankle trauma: MRI versus plain radiography

    International Nuclear Information System (INIS)

    Lohman, M.; Kivisaari, A.; Kivisaari, L.; Vehmas, T.

    2001-01-01

    Objective: To evaluate the diagnosis of acute physeal ankle fractures on plain radiographs using MRI as the gold standard. Methods: Sixty consecutive children, 29 with a clinical diagnosis of lateral ligament injury and 31 with physeal ankle fractures, were examined using both radiographs and MRI in the acute period. The imaging data were reviewed by three ''masked'' radiologists. The fracture diagnosis and Slater-Harris classification of radiographs were compared with findings on MRI. Results: Plain radiography produced five of 28 (18%) false negative and 12 of 92 (13%) false positive fracture diagnoses compared with MRI. Six of the 12 false positive fractures were due to a misclassification of lateral ligament disruption as SH1 fractures. Altogether a difference was found in 21% of cases in either the diagnosis or the classification of the fractures according to Salter- Harris. All bone bruises in the distal tibia and fibula and 64% of bone bruises in the talus were seen in association with lateral ligament injuries. Talar bone bruises in association with fractures occurred on the same side as the malleolar fracture; talar bone bruises in association with lateral ligament disruption were seen in different locations. The errors identified on radiographs by MRI did not affect the management of the injury. Conclusions: The incidence of false negative ankle fractures in plain radiographs was small and no complex ankle fractures were missed on radiographs. The total extent of complex fractures was, however, not always obvious on radiographs. In an unselected series of relatively mild ankle injuries, we were unable to show a single case where the treatment or prognosis based on plain radiography should have been significantly altered after having done a routine MRI examination. Plain radiography is still the diagnostic cornerstone of paediatric ankle injuries. (orig.)

  14. Linking groundwater dissolved organic matter to sedimentary organic matter from a fluvio-lacustrine aquifer at Jianghan Plain, China by EEM-PARAFAC and hydrochemical analyses.

    Science.gov (United States)

    Huang, Shuang-bing; Wang, Yan-xin; Ma, Teng; Tong, Lei; Wang, Yan-yan; Liu, Chang-rong; Zhao, Long

    2015-10-01

    The sources of dissolved organic matter (DOM) in groundwater are important to groundwater chemistry and quality. This study examined similarities in the nature of DOM and investigated the link between groundwater DOM (GDOM) and sedimentary organic matter (SOM) from a lacustrine-alluvial aquifer at Jianghan Plain. Sediment, groundwater and surface water samples were employed for SOM extraction, optical and/or chemical characterization, and subsequent fluorescence excitation-emission matrix (EEM) and parallel factor analyses (PARAFAC). Spectroscopic properties of bulk DOM pools showed that indices indicative of GDOM (e.g., biological source properties, humification level, aromaticity and molecule mobility) varied within the ranges of those of two extracted end-members of SOM: humic-like materials and microbe-associated materials. The coexistence of PARAFAC compositions and the sustaining internal relationship between GDOM and extracted SOM indicate a similar source. The results from principal component analyses with selected spectroscopic indices showed that GDOM exhibited a transition trend regarding its nature: from refractory high-humification DOM to intermediate humification DOM and then to microbe-associated DOM, with decreasing molecular weight. Correlations of spectroscopic indices with physicochemical parameters of the groundwater suggested that GDOM was released from SOM and was modified by microbial diagenetic processes. The current study demonstrated the associations of GDOM with SOM from a spectroscopic viewpoint and provided new evidence supporting SOM as the source of GDOM. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Evaluating the Quality and Accuracy of TanDEM-X Digital Elevation Models at Archaeological Sites in the Cilician Plain, Turkey

    Directory of Open Access Journals (Sweden)

    Stefan Erasmi

    2014-10-01

    Full Text Available Satellite remote sensing provides a powerful instrument for mapping and monitoring traces of historical settlements and infrastructure, not only in distant areas and crisis regions. It helps archaeologists to embed their findings from field surveys into the broader context of the landscape. With the start of the TanDEM-X mission, spatially explicit 3D-information is available to researchers at an unprecedented resolution worldwide. We examined different experimental TanDEM-X digital elevation models (DEM that were processed from two different imaging modes (Stripmap/High Resolution Spotlight using the operational alternating bistatic acquisition mode. The quality and accuracy of the experimental DEM products was compared to other available DEM products and a high precision archaeological field survey. The results indicate the potential of TanDEM-X Stripmap (SM data for mapping surface elements at regional scale. For the alluvial plain of Cilicia, a suspected palaeochannel could be reconstructed. At the local scale, DEM products from TanDEM-X High Resolution Spotlight (HS mode were processed at 2 m spatial resolution using a merge of two monostatic/bistatic interferograms. The absolute and relative vertical accuracy of the outcome meet the specification of high resolution elevation data (HRE standards from the National System for Geospatial Intelligence (NSG at the HRE20 level.

  16. Depletion of rice as food of waterfowl wintering in the Mississippi Alluvial Valley

    Science.gov (United States)

    Greer, Danielle M.; Dugger, Bruce D.; Reinecke, Kenneth J.; Petrie, Mark J.

    2009-01-01

    Waterfowl habitat conservation strategies in the Mississippi Alluvial Valley (MAV) and several other wintering areas assume carrying capacity is limited by available food, and increasing food resources is an effective conservation goal. Because existing research on winter food abundance and depletion is insufficient to test this hypothesis, we used harvested rice fields as model foraging habitats to determine if waste rice seed is depleted before spring migration. We sampled rice fields (n = 39 [winter 2000-2001], n = 69 [2001-2002]) to estimate seed mass when waterfowl arrived in late autumn and departed in late winter. We also placed exclosures in subsets of fields in autumn (n = 8 [2000-2001], n = 20 [2001-2002]) and compared seed mass inside and outside exclosures in late winter to estimate rice depletion attributable to waterfowl and other processes. Finally, we used an experiment to determine if the extent of rice depletion differed among fields of varying initial abundance and if the seed mass at which waterfowl ceased foraging or abandoned fields differed from a hypothesized giving-up value of 50 kg/ha. Mean seed mass was greater in late autumn 2000 than 2001 (127.0 vs. 83.9 kg/ha; P = 0.018) but decreased more during winter 2000-2001 than 2001-2002 (91.3 vs. 55.7 kg/ha) and did not differ at the end of winter (35.8 vs. 28.3 kg/ha; P = 0.651). Assuming equal loss to deterioration inside and outside exclosures, we estimated waterfowl consumed 61.3 kg/ha (48.3%) of rice present in late autumn 2000 and 21.1 kg/ha (25.1%) in 2001. When we manipulated late-autumn rice abundance, mean giving-up mass of rice seed was similar among treatments (48.7 kg/ha; P = 0.205) and did not differ from 50 kg/ha (P = 0.726). We integrated results by constructing scenarios in which waterfowl consumed rice at different times in winter, consumption and deterioration were competing risks, and consumption occurred only above 50 kg/ha. Results indicated waterfowl likely consumed

  17. Nutrient fluxes in litterfall of a secondary successional alluvial rain forest in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Maurício Bergamini Scheer

    2011-12-01

    Full Text Available During forest succession, litterfall nutrient fluxes increase significantly. The higher inputs of organic matter and nutrients through litterfall affects positively soil fertility and the species composition, which are essential components in forest restoration and management programs. In the present study, the input of nutrients to the forest soil via litterfall components was estimated for two sites of different development stages, in an early successional alluvial rain forest in Brazil. Litterfall returned to the soil, in kg/ha, ca. 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu and 11.2 Al, in the site where trees were more abundant and had higher values of basal area. In the other area, where trees where less abundant and values of basal area were comparatively low, litterfall returned Durante la sucesión secundaria forestal, el flujo de nutrientes en la hojarasca se incrementa significativamente. Los altos ingresos de materia orgánica y nutrientes a través de la hojarasca afecta positivamente la fertilidad del suelo y la composición de especies, las cuales son componentes esenciales para programas de restauración forestal y de manejo. En el presente estudio, el ingreso de nutrientes a través de la hojarasca y sus componentes fueron estimados para dos sitios de una selva lluviosa atlántica aluvial en sucesión temprana. La cantidad anual de elementos que ingresan al suelo desde la vegetación más desarrollada (sitios con alta área basal y abundancia de árboles fueron (en kg/ha: 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu y 11.2 Al. Menos de la mitad de esas cantidades fueron aportadas por la vegetación menos desarrollada, excepto para el Al. La cantidad de Al aportada a este sitio fue similar a la contribución de la vegetación más desarrollada, debido a la contribución de: Tibouchina pulchra (82% de todo el Al aportado. La eficiencia en el uso de nutrientes de la hojarasca

  18. The role of the uncertainty in assessing future scenarios of water shortage in alluvial aquifers

    Science.gov (United States)

    Romano, Emanuele; Camici, Stefania; Brocca, Luca; Moramarco, Tommaso; Guyennon, Nicolas; Preziosi, Elisabetta

    2015-04-01

    There are many evidences that the combined effects of variations in precipitation and temperature due to climate change can result in a significant change of the recharge to groundwater at different time scales. A possible reduction of effective infiltration can result in a significant decrease, temporary or permanent, of the availability of the resource and, consequently, the sustainable pumping rate should be reassessed. In addition to this, one should also consider the so called indirect impacts of climate change, resulting from human intervention (e.g. augmentation of abstractions) which are feared to be even more important than the direct ones in the medium term: thus, a possible increase of episodes of shortage (i.e. the inability of the groundwater system to completely supply the water demand) can result both from change in the climate forcing and change in the demand. In order to assess future scenarios of water shortage a modelling chain is often used. It includes: 1) the use of General Circulation Models to estimate changes in temperature and precipitation; 2) downscaling procedures to match modeling scenarios to the observed meteorological time series; 3) soil-atmosphere modelling to estimate the time variation of the recharge to the aquifer; 4) groundwater flow models to simulate the water budget and piezometric head evolution; 5) future scenarios of groundwater quantitative status that include scenarios of demand variation. It is well known that each of these processing steps is affected by an intrinsic uncertainty that propagates through the whole chain leading to a final uncertainty on the piezometric head scenarios. The estimate of such an uncertainty is a key point for a correct management of groundwater resources, in case of water shortage due to prolonged droughts as well as for planning purposes. This study analyzes the uncertainty of the processing chain from GCM scenarios to its impact on an alluvial aquifer in terms of exploitation

  19. Artificial urethral sphincters: Value of plain film radiography in evaluation of prosthesis malfunction

    International Nuclear Information System (INIS)

    Rose, S.C.; Hansen, M.E.; Webster, G.; Dunnick, N.R.

    1987-01-01

    Case records were reviewed to determine the diagnostic efficacy of plain radiographs in the evaluation of inflatable artificial urethral sphincters. Of 84 patients with prostheses, 21 (25%) developed complications. Fluid leaks were found in 16 patients who presented with recurrent incontinence; plain radiographs demonstrated an interval decrease in balloon reservoir diameter. Kinked tubing, which was evident on plain films, caused acute urinary retention in three patients. However, plain radiographs failed to detect evidence of prosthesis erosion into the urethra in either of two patients with this complication. Although urethroscopy is needed to detect urethral erosion, plain radiographs are inexpensive and reliable in the initial evaluation of artifical sphincter malfunction

  20. Ocean-Bottom Topography: The Divide between the Sohm and Hatteras Abyssal Plains.

    Science.gov (United States)

    Pratt, R M

    1965-06-18

    A compilation of precision echo soundings has delineated the complex topography between the Sohm and Hatteras abyssal plains off the Atlantic coast of the United States. At present the divide between the two plains is a broad, flat area about 4950 meters deep; however, the configuration of channels and depressions suggests spillage of turbidity currents from the Sohm Plain into the Hatteras Plain and a shifting of the divide toward the northeast. Hudson Canyon terminates in the divide area and has probably fed sediment into both plains.

  1. Sources, lability and solubility of Pb in alluvial soils of the River Trent catchment, U.K.

    Science.gov (United States)

    Izquierdo, M; Tye, A M; Chenery, S R

    2012-09-01

    Alluvial soils are reservoirs of metal contaminants such as Pb that originate from many different sources and are integrated temporally and spatially through erosional and depositional processes. In this study the source, lability and solubility of Pb were examined in a range of alluvial soils from the middle and lower River Trent and its tributary the River Dove using Pb isotope apportionment and isotopic dilution. All samples were collected within 10 m of the river bank to represent the soil that is most likely to be remobilised during bank erosion. Paired samples were taken from the topsoil (0-15 cm) and subsoil (35-50 cm) to assess differences with depth. Lead concentrations in soil ranged from 43 to 1282 mg/kg. The lability of soil Pb varied between 9 and 56% of total metal concentration whilst Pb concentrations in pore water varied between 0.2 and 6.5 μg/L. There was little difference in the % Pb lability between paired top and sub soils, possibly because soil characteristics such as pH, iron oxides and clay content were generally similar; a result of the recycling of eroded and deposited soils within the river system. Soil pH was found to be negatively correlated with % Pb lability. Source apportionment using (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios showed that the isotopic ratios of Pb in the total, labile and solution pools fitted along a mixing line between Broken Hill Type ('BHT') Pb, used as an additive in UK petrol, and the local coal/Southern Pennine ore Pb. Various anomalies were found in the Pb isotopes of the bankside alluvial soils which were explained by point source pollution. Statistically significant differences were found between (i) the isotopic composition of Pb in the total soil pool and the labile/solution pools and (ii) the isotopic composition of Pb in the labile and solution pools, suggesting an enrichment of recent non-Pennine sources of Pb entering the soils in the labile and solution pools. Copyright © 2012 Natural Environment

  2. Depositional Architecture of Late Pleistocene-Holocene Coastal Alluvial-fan System in the Coastal Range, Taiwan

    Science.gov (United States)

    Chen, S. T.; Chen, W. S.

    2016-12-01

    Since late Pleistocene, the Coastal Range (Philippine Sea plate) collided and overridden on the Central Range (Eurasian Plate) along the Longitudinal Valley Fault. Therefore, the Coastal Range is exposed widely the late Pleistocene-Holocene marine and fluvial terraces caused by the tectonic uplift. Based on the estimation of paleosea-level elevations (Δh), depositional paleodepth, altitude distribution of Holocene deposits (D), altitude of outcrops (H), and 14C dating of marine deposits (t), the uplift rate (=(Δh+H +d-D)/t) is about 5-10 mm/yr in the southern Coastal Range. In this study, we suggest through field logging that the deposits can be divided into alluvial, foreshore (intertidal), shoreface, and offshore environments. In Dulan area in the southern Coastal Range, the uplift rate was 6-7 mm/yr during 16,380-10,000 cal yr BP and 3-4 mm/yr after 7,000 cal yr BP. Results from the Dulan Coastal alluvial-fan system can be divided into five depositional stages: (1) 16,380-14,300 cal yr BP: The rate of global sea level rise (SLR) has averaged about 6-7 mm/yr, similar to the tectonic uplift rate. In this stage, the bedrock was eroded and formed a wide wave-cut platform. (2) 14,300-10,000 cal yr BP: SLR of about 14 mm/yr that was faster than tectonic uplift rate of 6-7 mm/yr. As a result of transgression, the beach-lagoon deposits about 5 m thick were unconformably overlain on the wave-cut platform. (3) 10,000-8,200 cal yr BP: The ongoing sea level rise (SLR: 11 mm/yr), the lagoon deposits were overlain by an offshore slump deposits representing a gradual deepening of the depositional environment. (4) 8,200-7,930 cal yr BP (SLR: 6-7 mm/yr): The tectonic uplift rate may occur at similar SLR. The alluvial-fan deposits have prograded over the shallow marine deposits. (5) After 7,000 cal yr BP (SLR: 1-0 mm/yr): SLR was much slower than tectonic uplift rate of 3-4 mm/yr. Thus, Holocene marine terraces are extensively developed in the coastal region, showing that the

  3. A real options model to assess the role of flexibility in forestry and agroforestry adoption and disadoption in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

    2013-01-01

    Efforts to restore the Lower Mississippi Alluvial Valley’s forests have not achieved desired levels of ecosystem services production.We examined how the variability of returns and the flexibility to change or postpone decisions (option value) affects the economic potential of forestry and agroforestry systems to keep private land in production while still providing...

  4. A Real Options Method for Estimating the Adoption Potential of Forestry and Agroforestry Systems on Private Lands in the Lower Mississippi Alluvial Valley, USA

    Science.gov (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

    2010-01-01

    The Lower Mississippi River Alluvial Valley (LMAV), once was the largest forested bottom-land area in the continental United States, but has undergone widespread loss of forest through conversion to farmland. Restoration of forest functions and values has been a key conservation goal in the LMAV since the 1970s. This study utilizes a partial differential real options...

  5. Meteorological tower data for the Yucca Alluvial (YA) site and Yucca Ridge (YR) site: Final data report, July 1983-October 1984

    International Nuclear Information System (INIS)

    Church, H.W.; Freeman, D.L.; Boro, K.; Egami, R.T.

    1987-11-01

    The purpose of the NNWSI meteorological data collection program was to support environmental evaluations of site suitability for a nuclear waste repository. This is the last of a series of data summaries for the NNWSI Alluvial and Ridge Sites in southern Nevada. 3 refs., 3 figs., 6 tabs

  6. Root-collar diameter and third-year survival of three bottomland hardwoods planted on former agricultural fields in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Emile S. Gardiner; Douglass F. Jacobs; Ronald P. Overton; George Hernandez

    2009-01-01

    Athough the Lower Mississippi Alluvial Valley (LMAV) has experienced substantial afforestation of former agricultural fields during the past 2 decades, seedling standards that support satisfactory outplanting performance of bottomland hardwood tree species are not available. A series of experimental plantations, established on three afforestation sites in the LMAV,...

  7. Luminescence dating of Pleistocene alluvial sediments affected by the Alhama de Murcia fault (eastern Betics, Spain) – a comparison between OSL, IRSL and post-IRIRSL ages

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew S.; Buylaert, Jan-Pieter

    2012-01-01

    The ages of nine alluvial units, identified by the integration of data obtained from five trenches at the southern termination of the Alhama de Murcia Fault (AMF) (eastern Betics, Spain), are constrained using luminescence dating based on the Optically Stimulated Luminescence (OSL) from quartz...

  8. Geochemical characterization of the middle and late Pleistocene alluvial fan-dominated infill of the northern part of the Weihe Basin, Central China

    NARCIS (Netherlands)

    Rits, Daniël S.; Beets, Christiaan J.; Prins, Maarten A.; van Balen, Ronald T.; Troelstra, Simon R.; Luo, Chao; Wang, B.; Li, Xiaoqiang; Zhou, Jie; Zheng, Hongbo

    2017-01-01

    Major reorganizations in climate and tectonic regime occurred in East Asia during the Pleistocene, resulting in large-scale environmental changes. In this paper a detailed geochemical and mineralogical record of these changes is presented from a distal alluvial fan sedimentary sequence in the

  9. Early to high medieval colonization and alluvial landscape transformation of the Labe valley (Czech Republic): evaluation of archaeological, pollen and macrofossil evidence

    Czech Academy of Sciences Publication Activity Database

    Kozáková, Radka; Pokorný, P.; Mařík, Jan; Čulíková, Věra; Boháčová, Ivana; Pokorná, Adéla

    2014-01-01

    Roč. 23, č. 6 (2014), s. 701-718 ISSN 0939-6314 R&D Projects: GA ČR GA404/08/1696 Institutional support: RVO:67985912 Keywords : human impact * medieval * pollen * macrofossils * stronghold * alluvial landscapes Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 2.648, year: 2014

  10. Fault-sourced alluvial fans and their interaction with axial fluvial drainage: An example from the Plio-Pleistocene Upper Valdarno Basin (Tuscany, Italy)

    Science.gov (United States)

    Fidolini, Francesco; Ghinassi, Massimiliano; Aldinucci, Mauro; Billi, Paolo; Boaga, Jacopo; Deiana, Rita; Brivio, Lara

    2013-05-01

    The present study deals with the fault-sourced, alluvial-fan deposits of the Plio-Pleistocene Upper Valdarno Basin (Northern Apennines, Italy). Different phases of alluvial fan aggradation, progradation and backstep are discussed as possible effects of the interaction among fault-generated accommodation space, sediment supply and discharge variations affecting the axial fluvial drainage. The Upper Valdarno Basin, located about 35 km SE of Florence, is filled with 550 m palustrine, lacustrine and alluvial deposits forming four main unconformity-bounded units (i.e. synthems). The study alluvial-fan deposits belong to the two uppermost synthems (Montevarchi and Torrente Ciuffenna synthems) and are Early to Middle Pleistocene in age. These deposits are sourced from the fault-bounded, NE margin of the basin and interfinger with axial fluvial deposits. Alluvial fan deposits of the Montevarchi Synthem consist of three main intervals: i) a lower interval, which lacks any evidence of a depositional trend and testify balance between the subsidence rate (i.e. fault activity) and the amount of sediment provided from the margin; ii) a coarsening-upward middle interval, pointing to a decrease in subsidence rate associated with an augment in sediment supply; iii) a fining-upward, upper interval (locally preserved), documenting a phase of tectonic quiescence associated with a progressive re-equilibration of the tectonically-induced morphological profile. The basin-scale unconformity, which separates the Montevarchi and Torrente Ciuffenna synthems was due to the entrance of the Arno River into the basin as consequence of a piracy. This event caused a dramatic increase in water discharge of the axial fluvial system, and its consequent embanking. Such an erosional surface started to develop in the axial areas, and propagated along the main tributaries, triggering erosion of the alluvial fan deposits. Alluvial-fan deposits of the Torrente Ciuffenna Synthem accumulated above the

  11. Climatic change in the Great Plains region of Canada

    International Nuclear Information System (INIS)

    Rizzo, B.

    1991-01-01

    Implications of global warming to Canada's Great Plains region are discussed, with reference to the climate predictions of the Goddard Institute for Space Studies (GISS) general circulation model under a two times atmospheric carbon dioxide concentration scenario. Two sets of climate variables for a geographic area located in the Great Plains are tabulated, for the current (1951-1980) climate normals and under the doubled carbon dioxide scenario. Simple univariate statistics were calculated for the two areas, for the variables of mean annual temperature, mean summer temperature, mean winter temperature, mean July temperature, mean growing season temperature, total annual precipitation, total summer precipitation, total winter precipitation, and total growing season precipitation. Under the GISS scenario, temperature values are on average 4 degree C higher than 1951-1980 normals, while precipitation remains about the same. Locations of ecoclimatic regions are graphed for the whole of Canada. 1 fig., 1 tab

  12. Computed tomography and plain radiography in experimental fracture healing

    International Nuclear Information System (INIS)

    Braunstein, E.M.; Goldstein, S.A.; Ku, J.; Smith, P.; Matthews, L.S.

    1986-01-01

    We evaluated the relative contribution of plain radiographs and computed tomography to the assessment of fracture healing under experimental circumstances. In 15 sheep, we performed midshaft femoral osteotomies and internal fixation of the resultant segmental fractures. Radiographs were obtained preoperatively and immediately postoperatively. Animals were sacrificed at 3 weeks, 6 weeks, 12 weeks, 24 weeks, and 36 weeks after surgery, and the femoral specimens radiographed. After removal of the internal fixation devices, computed tomographic scans of the specimens were performed. Computed tomography may be of value in the evaluation of fractures of long bones in those cases in which clinical examination and plain radiographs fail to give adequate information as to the status of healing. (orig./SHA)

  13. A Wear Geometry Model of Plain Woven Fabric Composites

    Directory of Open Access Journals (Sweden)

    Gu Dapeng

    2014-09-01

    Full Text Available The paper g describes a model meant for analysis of the wear geometry of plain woven fabric composites. The referred model consists of a mathematical description of plain woven fabric based on Peirce’s model coupled with a stratified method for the solution of the wear geometry. The evolutions of the wear area ratio of weft yarn, warp yarn and matrix resin on the worn surface are simulated by MatLab software in combination of warp and weft yarn diameters, warp and weft yarn-to-yarn distances, fabric structure phases (SPs. By comparing theoretical and experimental results from the PTFE/Kevlar fabric wear experiment, it can be concluded that the model can present a trend of the component area ratio variations along with the thickness of fabric, but has a inherently large error in quantitative analysis as an idealized model.

  14. Comparison among chemical, mineralogical and physical analysis from alluvial clays from counties of Southwest of Minas Gerais state (Brazil)

    International Nuclear Information System (INIS)

    Gaspar Junior, L.A.; Varajao, A.F.D.C.; Souza, M.H.O.; Moreno, M.M.T.

    2011-01-01

    The studied area is located in the southwestern portion of Minas Gerais State, encompassing the counties of Alfenas, Areado, Machado, Poco Fundo, Campestre, Serrania, Monte Belo, Bandeira do Sul, Botelhos and Cabo Verde. This region is dominated by strongly weathered pre-cambrian rocks in association with colluvial-alluvial sediments. The present work consisted in a comparison among the mineralogical (X-Ray Diffraction), textural (Laser Granulometry), chemical (X-Ray Fluorescence) and technological (mechanical resistance, water absorption, etc, made in specimen tests) properties of the clays collected on potteries located in these counties. The mineralogical and chemical analysis displayed the kaolinitic nature of the clays from this region, showing also small amount of interlayered clays and large amount of quartz. The best results of physical analysis were obtained for clays from the counties of Cabo Verde and Monte Belo due to the presence of lower values of SiO 2 (quartz) associated with a finer particle size distribution. (author)

  15. Drinking Water Quality Criterion - Based site Selection of Aquifer Storage and Recovery Scheme in Chou-Shui River Alluvial Fan

    Science.gov (United States)

    Huang, H. E.; Liang, C. P.; Jang, C. S.; Chen, J. S.

    2015-12-01

    Land subsidence due to groundwater exploitation is an urgent environmental problem in Choushui river alluvial fan in Taiwan. Aquifer storage and recovery (ASR), where excess surface water is injected into subsurface aquifers for later recovery, is one promising strategy for managing surplus water and may overcome water shortages. The performance of an ASR scheme is generally evaluated in terms of recovery efficiency, which is defined as percentage of water injected in to a system in an ASR site that fulfills the targeted water quality criterion. Site selection of an ASR scheme typically faces great challenges, due to the spatial variability of groundwater quality and hydrogeological condition. This study proposes a novel method for the ASR site selection based on drinking quality criterion. Simplified groundwater flow and contaminant transport model spatial distributions of the recovery efficiency with the help of the groundwater quality, hydrological condition, ASR operation. The results of this study may provide government administrator for establishing reliable ASR scheme.

  16. Arboreous vegetation of an alluvial riparian forest and their soil relations: Porto Rico island, Paraná river, Brazil

    Directory of Open Access Journals (Sweden)

    Campos João Batista

    2002-01-01

    Full Text Available The dynamics of alluvial deposits in floodplains forms islands and sandbanks. Deposits frequently accumulate at the river margins and on islands with consequent side growths. One of these sandbanks which started to form in 1952 annexed an area of 12.4ha to the Porto Rico island (53masculine15?W and 22masculine45?S. At present a forest fragment of approximately 2.0 ha exists in this place. The structural analysis of arboreous vegetation of this fragment showed a floristic gradient related to the physical and chemical variations of the substratum. High density of pioneer species associated to the absence of recruitment of new individuals of these and other successional categories indicated that the forest was impaired in its succession process. This fact could be associated with constant disturbances caused by cattle in the area.

  17. NAA of the 'Minoan pumice' at Thera and comparison to alluvial pumice deposits in the Eastern Mediterranean region

    International Nuclear Information System (INIS)

    Bichler, M.; Egger, H.; Preisinger, A.; Ritter, D.; Stastny, P.

    1997-01-01

    Neutron activation analysis was used to determine up to 30 elements in the pumice layers from the 'Minoan eruption' at Thera (Santorini, Greece). Mt Pilato (Lipari, Italy) and in alluvial pumice from coasts of the Eastern Mediterranean region. The morphologically well distinguishable layers of the 'Minoan pumice' were found to be of nearly similar composition in respect to the elements determined and their distribution patterns could therefore be used to identify a sample as Santorinian or not. Additionally, this method was applied to pumice lumps found during archaeological excavations in the Nile delta, Egypt. The results showed that two of the three Egyptian samples are products of the Minoan eruption at Thera and therefore chronologically useful. A second group of pumices collected at Antalya (Turkey), Crete (Greece) and also in Egypt was found to have a distinctly different composition and is therefore related to another volcanic event. (author)

  18. Characteristics of ejecta and alluvial deposits at Meteor Crater, Arizona and Odessa Craters, Texas: Results from ground penetrating radar

    Science.gov (United States)

    Grant, J. A.; Schultz, P. H.

    1991-01-01

    Previous ground penetrating radar (GRP) studies around 50,000 year old Meteor Crater revealed the potential for rapid, inexpensive, and non-destructive sub-surface investigations for deep reflectors (generally greater than 10 m). New GRP results are summarized focusing the shallow sub-surfaces (1-2 m) around Meteor Crater and the main crater at Odessa. The following subject areas are covered: (1) the thickness, distribution, and nature of the contact between surrounding alluvial deposits and distal ejecta; and (2) stratigraphic relationships between both the ejecta and alluvium derived from both pre and post crater drainages. These results support previous conclusions indicating limited vertical lowering (less than 1 m) of the distal ejecta at Meteor Crater and allow initial assessment of the gradational state if the Odessa craters.

  19. Obsidian from volcanic sequences and rent alluvial deposits, Erzurum district, north-eastern Anatolia: Chemical characterisation and archaeological implications

    International Nuclear Information System (INIS)

    Brennan, P.; Sagona, T.

    1997-01-01

    Full text: Recent geoarchaeological research in the Erzurum district, north-eastern Anatolia, has revealed an abundance of obsidian at numerous neolithic and Bronze Age sites. Geochemical characterisation using neutron activation analysis indicates that the obsidian was obtained from several sources that are chemically distinct from the major sources already known from Central Anatolia an the Lake Van area. Multiple sources are represented in the samples collected from at least two of the sites, namely the sites of Sos and Pulur. The primary source of some of the obsidian utilised at the site of Sos has been located in the volcanic sequence outcropping tot he north-west of Pasinler. Field survey however has shown that the alluvial deposits along the main rivers and some of their tributaries were the main sources of the obsidian utilised at the sites near Erzurum. Trade or exchange of obsidian with sites outside the Erzurum area seems to have been limited

  20. Analysis and assessment on heavy metal sources in the coastal soils developed from alluvial deposits using multivariate statistical methods.

    Science.gov (United States)

    Li, Jinling; He, Ming; Han, Wei; Gu, Yifan

    2009-05-30

    An investigation on heavy metal sources, i.e., Cu, Zn, Ni, Pb, Cr, and Cd in the coastal soils of Shanghai, China, was conducted using multivariate statistical methods (principal component analysis, clustering analysis, and correlation analysis). All the results of the multivariate analysis showed that: (i) Cu, Ni, Pb, and Cd had anthropogenic sources (e.g., overuse of chemical fertilizers and pesticides, industrial and municipal discharges, animal wastes, sewage irrigation, etc.); (ii) Zn and Cr were associated with parent materials and therefore had natural sources (e.g., the weathering process of parent materials and subsequent pedo-genesis due to the alluvial deposits). The effect of heavy metals in the soils was greatly affected by soil formation, atmospheric deposition, and human activities. These findings provided essential information on the possible sources of heavy metals, which would contribute to the monitoring and assessment process of agricultural soils in worldwide regions.

  1. Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil).

    Science.gov (United States)

    Camargo, M; Giarrizzo, T; Jesus, A J S

    2015-08-01

    The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

  2. Optimal Equipment Investments for Northern Plains Grain Farms

    OpenAIRE

    Terrance Jalbert; Mercedes Jalbert; James E. Briley

    2010-01-01

    This case presents a teaching tool which requires students to identify an optimal equipment plan for a northern plains small grain farm. Students are presented with information from a farm owner regarding farm size, available labor, farming techniques used and other relevant issues. Students are required to analyze this information to identify the equipment necessary to operate the farm. Students must balance equipment costs and labor issues. They must develop a plan that remains within a pre...

  3. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran

    OpenAIRE

    Mohammad Reza Vesali Naseh; Roohollah Noori; Ronny Berndtsson; Jan Adamowski; Elaheh Sadatipour

    2018-01-01

    Although Iran’s Ghaen Plain provides saffron to much of the world, no regional groundwater quality (GQ) assessment has yet been undertaken. Given the region’s potential for saltwater intrusion and heavy metal contamination, it is important to assess the GQ and determine its main probable source of pollution (MPSP). Such knowledge would allow for informed mitigation or elimination of the potential adverse health effects of this groundwater through its use as drinking water, or indirectly as a ...

  4. Promoting innovative stormwater solutions for coastal plain communities

    OpenAIRE

    Drescher, Sadie

    2010-01-01

    In 2008, the Center for Watershed Protection (CWP) surveyed seventy-three coastal plain communities to determine their current practices and need for watershed planning and low impact development (LID). The survey found that communities had varying watershed planning effectiveness and need better stormwater management, land use planning, and watershed management communication. While technical capacity is improving, stormwater programs are under staffed and innovative site designs ...

  5. Carpal pseudoerosions: a plain X-ray interpretation pitfall

    Energy Technology Data Exchange (ETDEWEB)

    Wawer, Richard [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Budzik, Jean Francois [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires; Demondion, Xavier [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; CHRU Lille (France). Lab. d' Anatomie; Forzy, Gerard [Univ. Catholique de Lille, Lomme (France). Lab. de Biologie; Cotten, Anne [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires

    2014-10-15

    To examine in detail images of pseudoerosion of the wrist and hand on plain radiographs. The study was conducted with 28 cadaver wrists. During a single imaging session three techniques - plain radiography, tomosynthesis, and computed tomography - were used to visualize the wrist and hand specimens. For each technique, 20 radio-ulno-carpo-metacarpal sites known to present bone erosions in rheumatoid arthritis were analyzed by two radiologists using a standard system to score the cortical bone: normal, pseudoerosion, true erosion, or other pathology. Cohen's concordance analysis was performed to determine inter-observer and intra-observer (for the senior radiologist) agreement by site and by technique. Serial sections of two cadaver specimens were examined to determine the anatomical correlation of the pseudoerosions. On the plain radiographs, the radiologists scored many images as pseudoerosion (7.3 %), particularly in the distal ulnar portion of the capitate, the distal radial portion of the hamate, the proximal ulnar portion of the base of the third metacarpal, the proximal radial portion of the base of the fourth metacarpal, the distal ulnar portion of the hamate, and the proximal portion of the base of the fifth metacarpal. The computed tomography scan revealed that none of these doubtful images corresponded to true erosions. The anatomical correlation study showed that these images could probably be attributed to ligament insertions, thinner lamina, and enhanced cortical bone transparency. Knowledge of the anatomical carpal localizations where pseudoerosions commonly occur is a necessary prerequisite for analysis of plain radiographs performed to diagnose or monitor rheumatoid arthritis. (orig.)

  6. Herbage productivity of the Winneba plains of Ghana | Fleischer ...

    African Journals Online (AJOL)

    The biomass productivity of the Winneba plains of Ghana was measured between January 1990 and February 1992. Ten sampling sites were chosen for the study. An area of 5.0 m W 5.0 m was demarcated and within it an area of 1.0 m W 1.0 m was harvested at monthly intervals, clipped by means of sickle at 5 cm above ...

  7. Long term acroecosystem research in the Southern Plains

    Science.gov (United States)

    Jean L. Steiner; Patrick J. Starks; Jurgen Garbrecht; Daniel Moriasi; Paul Bartholomew; Jim Neel; Kenneth E. Turner; Brian Northup

    2016-01-01

    The Southern Plains (SP) site of the Long Term Agroecosystem Research (LTAR) network is headquartered at the USDA-ARS Grazinglands Research Laboratory (GRL) in El Reno, Oklahoma. The GRL was established in 1948. A long-term watershed and climate research program was established in the Little Washita River Experimental Watershed (LWREW) in 1961 and in the Fort Cobb...

  8. Suspended particulate studies over the Madeira Abyssal Plain

    International Nuclear Information System (INIS)

    Simpson, W.R.

    1987-01-01

    Various aspects relating to suspended matter over the Madeira Abyssal Plain are discussed. Special attention is paid to the nepheloid layer including resuspension and transport processes; time variabilities in particle concentrations and fluxes; particle morphology, microbiology and chemical composition; phase association of metals. Also, tentative predictions of the behaviour of some radionuclides are made based on theory and data on rare earth elements. Instrumentation developed for the project is detailed - the deep water particle sampler. (author)

  9. Simulating land management options to reduce nitrate pollution in an agricultural watershed dominated by an alluvial aquifer.

    Science.gov (United States)

    Cerro, Itsasne; Antigüedad, Iñaki; Srinavasan, Raghavan; Sauvage, Sabine; Volk, Martin; Sanchez-Perez, José Miguel

    2014-01-01

    The study area (Alegria watershed, Basque Country, Northern Spain) considered here is influenced by an important alluvial aquifer that plays a significant role in nitrate pollution from agricultural land use and management practices. Nitrates are transported primarily from the soil to the river through the alluvial aquifer. The agricultural activity covers 75% of the watershed and is located in a nitrate-vulnerable zone. The main objective of the study was to find land management options for water pollution abatement by using model systems. In a first step, the SWAT model was applied to simulate discharge and nitrate load in stream flow at the outlet of the catchment for the period between October 2009 and June 2011. The LOADEST program was used to estimate the daily nitrate load from measured nitrate concentration. We achieved satisfactory simulation results for discharge and nitrate loads at monthly and daily time steps. The results revealed clear variations in the seasons: higher nitrate loads were achieved for winter (20,000 kg mo NO-N), and lower nitrate loads were simulated for the summer (model was used to evaluate the long-term effects of best management practices (BMPs) for a 50-yr period by maintaining actual agricultural practices, reducing fertilizer application by 20%, splitting applications (same total N but applied over the growing period), and reducing 20% of the applied fertilizer amount and splitting the fertilizer doses. The BMPs were evaluated on the basis of local experience and farmer interaction. Results showed that reducing fertilizer amounts by 20% could lead to a reduction of 50% of the number of days exceeding the nitrate concentration limit value (50 mg L) set by the European Water Framework Directive. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. Debris flood hazard documentation and mitigation on the Tilcara alluvial fan (Quebrada de Humahuaca, Jujuy province, North-West Argentina

    Directory of Open Access Journals (Sweden)

    G. Marcato

    2012-06-01

    Full Text Available For some decades, mass wasting processes such as landslides and debris floods have been threatening villages and transportation routes in the Rio Grande Valley, named Quebrada de Humauhuaca. One of the most significant examples is the urban area of Tilcara, built on a large alluvial fan. In recent years, debris flood phenomena have been triggered in the tributary valley of the Huasamayo Stream and reached the alluvial fan on a decadal basis.

    In view of proper development of the area, hazard and risk assessment together with risk mitigation strategies are of paramount importance. The need is urgent also because the Quebrada de Humahuaca was recently included in the UNESCO World Cultural Heritage. Therefore, the growing tourism industry may lead to uncontrolled exploitation and urbanization of the valley, with a consequent increase of the vulnerability of the elements exposed to risk. In this context, structural and non structural mitigation measures not only have to be based on the understanding of natural processes, but also have to consider environmental and sociological factors that could hinder the effectiveness of the countermeasure works.

    The hydrogeological processes are described with reference to present-day hazard and risk conditions. Considering the socio-economic context, some possible interventions are outlined, which encompass budget constraints and local practices. One viable solution would be to build a protecting dam upstream of the fan apex and an artificial channel, in order to divert the floodwaters in a gully that would then convey water and sediments into the Rio Grande, some kilometers downstream of Tilcara. The proposed remedial measures should employ easily available and relatively cheap technologies and local workers, incorporating low environmental and visual impacts issues, in order to ensure both the future conservation of the site and its safe exploitation for inhabitants and tourists.

  11. Modeling and measuring the relationships between sediment transport processes, alluvial bedforms and channel-scale morphodynamics in sandy braided rivers.

    Science.gov (United States)

    Nicholas, A. P.; Ashworth, P. J.; Best, J.; Lane, S. N.; Parsons, D. R.; Sambrook Smith, G.; Simpson, C.; Strick, R. J. P.; Unsworth, C. A.

    2017-12-01

    Recent years have seen significant advances in the development and application of morphodynamic models to simulate river evolution. Despite this progress, significant challenges remain to be overcome before such models can provide realistic simulations of river response to environmental change, or be used to determine the controls on alluvial channel patterns and deposits with confidence. This impasse reflects a wide range of factors, not least the fact that many of the processes that control river behaviour operate at spatial scales that cannot be resolved by such models. For example, sand-bed rivers are characterised by multiple scales of topography (e.g., dunes, bars, channels), the finest of which must often by parameterized, rather than represented explicitly in morphodynamic models. We examine these issues using a combination of numerical modeling and field observations. High-resolution aerial imagery and Digital Elevation Models obtained for the sandy braided South Saskatchewan River in Canada are used to quantify dune, bar and channel morphology and their response to changing flow discharge. Numerical simulations are carried out using an existing morphodynamic model based on the 2D shallow water equations, coupled with new parameterisations of the evolution and influence of alluvial bedforms. We quantify the spatial patterns of sediment flux using repeat images of dune migration and bar evolution. These data are used to evaluate model predictions of sediment transport and morphological change, and to assess the degree to which model performance is controlled by the parametrization of roughness and sediment transport phenomena linked to subgrid-scale bedforms (dunes). The capacity of such models to replicate the characteristic multi-scale morphology of bars in sand-bed rivers, and the contrasting morphodynamic signatures of braiding during low and high flow conditions, is also assessed.

  12. Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer-aquitard complexes

    Science.gov (United States)

    Zhang, Yong; Green, Christopher T.; Tick, Geoffrey R.

    2015-01-01

    This study evaluates the role of the Peclet number as affected by molecular diffusion in transient anomalous transport, which is one of the major knowledge gaps in anomalous transport, by combining Monte Carlo simulations and stochastic model analysis. Two alluvial settings containing either short- or long-connected hydrofacies are generated and used as media for flow and transport modeling. Numerical experiments show that 1) the Peclet number affects both the duration of the power-law segment of tracer breakthrough curves (BTCs) and the transition rate from anomalous to Fickian transport by determining the solute residence time for a given low-permeability layer, 2) mechanical dispersion has a limited contribution to the anomalous characteristics of late-time transport as compared to molecular diffusion due to an almost negligible velocity in floodplain deposits, and 3) the initial source dimensions only enhance the power-law tail of the BTCs at short travel distances. A tempered stable stochastic (TSS) model is then applied to analyze the modeled transport. Applications show that the time-nonlocal parameters in the TSS model relate to the Peclet number, Pe. In particular, the truncation parameter in the TSS model increases nonlinearly with a decrease in Pe due to the decrease of the mean residence time, and the capacity coefficient increases with an increase in molecular diffusion which is probably due to the increase in the number of immobile particles. The above numerical experiments and stochastic analysis therefore reveal that the Peclet number as affected by molecular diffusion controls transient anomalous transport in alluvial aquifer–aquitard complexes.

  13. Debris flood hazard documentation and mitigation on the Tilcara alluvial fan (Quebrada de Humahuaca, Jujuy province, North-West Argentina)

    Science.gov (United States)

    Marcato, G.; Bossi, G.; Rivelli, F.; Borgatti, L.

    2012-06-01

    For some decades, mass wasting processes such as landslides and debris floods have been threatening villages and transportation routes in the Rio Grande Valley, named Quebrada de Humauhuaca. One of the most significant examples is the urban area of Tilcara, built on a large alluvial fan. In recent years, debris flood phenomena have been triggered in the tributary valley of the Huasamayo Stream and reached the alluvial fan on a decadal basis. In view of proper development of the area, hazard and risk assessment together with risk mitigation strategies are of paramount importance. The need is urgent also because the Quebrada de Humahuaca was recently included in the UNESCO World Cultural Heritage. Therefore, the growing tourism industry may lead to uncontrolled exploitation and urbanization of the valley, with a consequent increase of the vulnerability of the elements exposed to risk. In this context, structural and non structural mitigation measures not only have to be based on the understanding of natural processes, but also have to consider environmental and sociological factors that could hinder the effectiveness of the countermeasure works. The hydrogeological processes are described with reference to present-day hazard and risk conditions. Considering the socio-economic context, some possible interventions are outlined, which encompass budget constraints and local practices. One viable solution would be to build a protecting dam upstream of the fan apex and an artificial channel, in order to divert the floodwaters in a gully that would then convey water and sediments into the Rio Grande, some kilometers downstream of Tilcara. The proposed remedial measures should employ easily available and relatively cheap technologies and local workers, incorporating low environmental and visual impacts issues, in order to ensure both the future conservation of the site and its safe exploitation for inhabitants and tourists.

  14. Characterising alluvial aquifers in a remote ephemeral catchment (Flinders River, Queensland) using a direct push tracer approach

    Science.gov (United States)

    Taylor, Andrew R.; Smith, Stanley D.; Lamontagne, Sébastien; Suckow, Axel

    2018-01-01

    The availability of reliable water supplies is a key factor limiting development in northern Australia. However, characterising groundwater resources in this remote part of Australia is challenging due to a lack of existing infrastructure and data. Here, direct push technology (DPT) was used to characterise shallow alluvial aquifers at two locations in the semiarid Flinders River catchment. DPT was used to evaluate the saturated thickness of the aquifer and estimate recharge rates by sampling for environmental tracers in groundwater (major ions, 2H, 18O, 3H and 14C). The alluvium at Fifteen Mile Reserve and Glendalough Station consisted of a mixture of permeable coarse sandy and gravely sediments and less permeable clays and silts. The alluvium was relatively thin (i.e. < 20 m) and, at the time of the investigation, was only partially saturated. Tritium (3H) concentrations in groundwater was ∼1 Tritium Unit (TU), corresponding to a mean residence time for groundwater of about 12 years. The lack of an evaporation signal for the 2H and 18O of groundwater suggests rapid localised recharge from overbank flood events as the primary recharge mechanism. Using the chloride mass balance technique (CMB) and lumped parameter models to interpret patterns in 3H in the aquifer, the mean annual recharge rate varied between 21 and 240 mm/yr. Whilst this recharge rate is relatively high for a semiarid climate, the alluvium is thin and heterogeneous hosting numerous alluvial aquifers with varied connectivity and limited storage capacity. Combining DPT and environmental tracers is a cost-effective strategy to characterise shallow groundwater resources in unconsolidated sedimentary aquifers in remote data sparse areas.

  15. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region

    Science.gov (United States)

    Zúñiga de León, David; Kershaw, Stephen; Mahan, Shannon

    2016-01-01

    Alluvial fans formed from sediments derived from erosion of the Juárez Mountains in northernmost México have a significant flood impact on the Ciudad Juárez, which is built on the fan system. The northern part of Ciudad Juárez is the most active; further south, older parts of the fan, upon which the rest of the city is built, were largely eroded by natural processes prior to human habitation and subsequently modified only recently by human construction. Three aeolian sand samples, collected from the uppermost (youngest) parts of the fan system in the city area, in places where human intervention has not disturbed the sediment, and constrain the latest dates of fan building. Depositional ages of the Quaternary alluvial fans were measured using Optically Stimulated Luminescence (OSL) on aeolian sands that have inter-fingered with alluvial fan material. These dates are: a) sample P1, 31 ka; b) sample P2, 41 ka; c) sample P3, 74 ka, between Oxygen Isotope Stages (OIS) 3 to 5. They demonstrate that fan development, in the area now occupied by the city, terminated in the Late Pleistocene, immediately after what we interpret to have been an extended period of erosion without further deposition, lasting from the Late Pleistocene to Holocene. The three dates broadly correspond to global glacial periods, implying that the cool, dry periods may reflect periods of aeolian transport in northern México in between phases that were wetter to form the alluvial fans. Alluvial fan margins inter-finger with fluvial terrace sediments derived from the Río Bravo, indicating an additional component of fan dissection by Río Bravo lateral erosion, presumed to be active during earlier times than our OSL ages, but these are not yet dated. Further dating is required to ascertain the controls on the fan and fluvial system.

  16. Geomorphic and hydraulic controls on large-scale riverbank failure on a mixed bedrock-alluvial river system, the River Murray, South Australia: a bathymetric analysis.

    Science.gov (United States)

    De Carli, E.; Hubble, T.

    2014-12-01

    During the peak of the Millennium Drought (1997-2010) pool-levels in the lower River Murray in South Australia dropped 1.5 metres below sea level, resulting in large-scale mass failure of the alluvial banks. The largest of these failures occurred without signs of prior instability at Long Island Marina whereby a 270 metre length of populated and vegetated riverbank collapsed in a series of rotational failures. Analysis of long-reach bathymetric surveys of the river channel revealed a strong relationship between geomorphic and hydraulic controls on channel width and downstream alluvial failure. As the entrenched channel planform meanders within and encroaches upon its bedrock valley confines the channel width is 'pinched' and decreases by up to half, resulting in a deepening thalweg and channel bed incision. The authors posit that flow and shear velocities increase at these geomorphically controlled 'pinch-points' resulting in complex and variable hydraulic patterns such as erosional scour eddies, which act to scour the toe of the slope over-steepening and destabilising the alluvial margins. Analysis of bathymetric datasets between 2009 and 2014 revealed signs of active incision and erosional scour of the channel bed. This is counter to conceptual models which deem the backwater zone of a river to be one of decelerating flow and thus sediment deposition. Complex and variable flow patterns have been observed in other mixed alluvial-bedrock river systems, and signs of active incision observed in the backwater zone of the Mississippi River, United States. The incision and widening of the lower Murray River suggests the channel is in an erosional phase of channel readjustment which has implications for riverbank collapse on the alluvial margins. The prevention of seawater ingress due to barrage construction at the Murray mouth and Southern Ocean confluence, allowed pool-levels to drop significantly during the Millennium Drought reducing lateral confining support to the

  17. Systematic assessment of constipation on plain abdominal radiographs in children

    International Nuclear Information System (INIS)

    Bosch, Maurice van den; Graafmans, Doortje; Nievelstein, Rutger; Beek, Erik

    2006-01-01

    Constipation in childhood is common and its clinical assessment is often difficult. Plain abdominal radiography is simple and used to quantify constipation. Three scoring systems, those of Barr et al., Leech et al. and Blethyn et al., have been developed to quantify fecal loading on the abdominal radiograph. In order to determine which method is the most useful in clinical practice, we assessed the reproducibility of the three scoring systems. Plain abdominal radiographs from 40 clinically constipated children were retrospectively reviewed by two paediatric radiologists on two separate occasions. The radiographs were scored according to three different systems developed by Barr et al., Leech et al., Blethyn et al. Intraobserver variability and interobserver reproducibility were determined for each system. Kappa coefficients were calculated as indicators of inter- and intraobserver agreement for categorical outcome variables. The Leech score showed the highest reproducibility: the intraobserver agreement was high for both observers (κ values of 0.88 and 1.00, respectively, P<0.05). Furthermore, the interobserver agreement was also high: κ 0.91 in the first round and 0.84 in the second. The Leech score proved to be a highly reproducible tool for assessment of childhood constipation and is of value in clinical practice for systematic assessment of constipation on plain abdominal radiographs in children. (orig.)

  18. Acute neuropathic joint in diabetic foot: Plain radiographic findings

    International Nuclear Information System (INIS)

    Yoon, Dae Young; Kang, Heung Sik; Sim, Jung Suk; Yoon, Yong Kyu; Kim, Chu Wan

    1994-01-01

    To determine the plain film findings of acute neuropathic joint in diabetic foot. Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in followed-up radiographs, and deformities after healing. The time interval between clinical onset of gangrene and bone destruction ranges from 2 weeks to 4 weeks(mean 2.6 weeks). Plane radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. Rapid disorganisation of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy

  19. Diagnosis of lumbar central spinal stenosis by plain radiography

    International Nuclear Information System (INIS)

    Ilkko, E.

    1989-01-01

    The usefulness of plain radiography in the diagnosis of lumbar central spinal stenosis was studied in 116 patients using computed tomography (CT) as a reference. The most significant signs found in central spinal stenosis were short pedicles, high narrow intervertebral foramina, small interlaminar windows and deep posterior concavity of the vertebral bodies. The sensitivity of plain radiography in the diagnosis of central spinal stenosis as compared to CT was 66%, the specificity was 93% and the accuracy was 86%. The midsagittal and interpedicular diameters were measured from plain radiograms and were compared with corresponding CT diameters. In approximately half of the cases, the sagittal diameters were compatible. The maximum error was 6 mm. On average, the interpedicular distances were measured as too wide. The reliability of CT measurements were established by taking the measurements from the vertebral column of a moose calf, and then comparing these to the real measurements obtained with a calibrated ruler. The maximal differences were 2 mm. (author). 24 refs.; 8 figs.; 3 tabs

  20. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Vesali Naseh

    2018-01-01

    Full Text Available Although Iran’s Ghaen Plain provides saffron to much of the world, no regional groundwater quality (GQ assessment has yet been undertaken. Given the region’s potential for saltwater intrusion and heavy metal contamination, it is important to assess the GQ and determine its main probable source of pollution (MPSP. Such knowledge would allow for informed mitigation or elimination of the potential adverse health effects of this groundwater through its use as drinking water, or indirectly as a result of the consumption of groundwater-irrigated crops. Total dissolved solids, sodium, and chloride in the water of the majority of 16 wells sampled within the region exceeded World Health Organization and Iranian permissible standards for drinking water. The groundwater proved to only be suitable for irrigating salt tolerant crops under good drainage conditions. Due to the precipitation of calcium carbonate in the water supply facilities, the water from all wells was deemed unsuitable for industrial purposes. Heavy metal pollution and contamination indices showed no groundwater contamination. Analysis of ionic ratios and the application of principal components analysis indicated the MPSP to be saltwater intrusion, with the geology subtending the plain, and to a lesser extent, anthropogenic activities. Reducing groundwater withdrawals, particularly those for agricultural production by using high performance irrigation methods could reduce saltwater intrusion and improve GQ in the Ghaen Plain.