Sample records for alluvial plains

  1. Level IV Ecoregions of the Mississippi Alluvial Plain (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 III Ecoregions of the Mississippi Alluvial Plain (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. Calculation of the mercury accumulation in the Idrijca River alluvial plain sediments. (United States)

    Zibret, Gorazd; Gosar, Mateja


    From the historic literature on the Idrija mercury mine, it is evident that part of the smelting and mining waste was dumped into the Idrijca River. This waste was transported downstream during floods. The amount of mercury which has accumulated in the alluvial sediments of the Idrijca River until the present was studied. Mapping of Holocene river terraces of the Idrijca River was performed in order to estimate the volume of the alluvial sediment. For the purpose of the assessment of the mercury concentration, we sampled the alluvial sediments on different levels and performed an analysis of variance. The greatest variability is between the floodplain and terraces inside the same alluvial plain. Considering this fact, which determined the methodology employed for calculation, we estimated that about 2029 tons of mercury is stored in the Idrijca River alluvial sediments.

  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.


    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. Presettlement Pinus taeda in the Mississippi Valley Alluvial Plain of the Monroe County, Arkansas area (United States)

    Don C. Bragg


    Loblolly pine (Pinus taeda) is the most dominant conifer in the southeastern United States (Baker and Langdon, 1990). However, loblolly pine was conspicuously absent from virtually the entire Mississippi Valley Alluvial Plain during presettlement times. A map (Fig. 1) of the native distribution of loblolly from Baker and Langdon (1990) identifies 2 exceptions to this...

  6. Rainfall-induced nutrient losses from manure-fertilized farmland in an alluvial plain. (United States)

    Wang, Yiyao; Li, Huaizheng; Xu, Zuxin


    Nutrient transport and loss in farmlands are affected by factors such as land cover, fertilization, soil type, rainfall, and management practices. We investigated the temporal and spatial changes in macronutrient transport and loss after fertilization and precipitation in manure-fertilized eggplant farmland in an alluvial plain. Upon adding topical fertilizer, concentrations of most nutrients in runoff and groundwater increased, and nitrogen runoff increased from 22.11 to 35.81 kg/ha, although eggplant yield did not increase correspondingly. Incorporation of fertilizer by plowing reduced nutrient losses (nitrogen runoff/fertilizer decreased from 18.40 to 12.29 %). Measurements taken along the nutrient transport route (runoff, drainage ditch, groundwater, river water, and finally rainfall) revealed that concentrations of most nutrients declined at each stage. Nutrient characteristics varied by transport, and the forms of nitrogen and phosphorus differed greatly between runoff and groundwater (nitrate/nitrogen in runoff was ~43.49 %, while in groundwater ~5.41 %). Most nutrient concentrations in runoff decreased greatly during the planting season (total nitrogen decreased from 62.25 to 4.17 mg/L), correlated positively with temperature and stage of plant growth, but little temporal change was observed in groundwater. This field investigation during one planting season exemplifies the basic principles of nutrient loss and transport from manure-fertilized farmland in an alluvial plain.

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

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    Libing Liao


    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.

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

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    Rudy Erwiyono


    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

  9. Effects of the Biofuels Initiative on Water Quality and Quantity in the Mississippi Alluvial Plain (United States)

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


    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.

  10. Dissolved and solid-phase arsenic fate in an arsenic-enriched aquifer in the river Brahmaputra alluvial plain. (United States)

    Baviskar, Shirishkumar; Choudhury, Runti; Mahanta, Chandan


    Dissolved arsenic mobility in the environment is controlled by its associations with solid-phase As and other minerals by chemodynamics of adsorptions and co-precipitation. Arsenic mobilization potential and mechanisms in the groundwater of a part of the river Brahmaputra alluvial plain in India were inferred from aqueous and solid-phase geochemical analyses of groundwater samples and sediment cores from various depths. Sediments were analyzed for key parameters, e.g., total and sequentially extracted Fe, As, and Mn; organic carbon content; carbonate phases; and specific surface area, while groundwater samples collected from close proximity of the drilled bore well were analyzed for major and trace element hydrogeochemistry. Result shows Mn- and Fe-oxyhydroxides as the major leachable As solid phases. Median total leachable solid-phase As was found to be ~9.50 mg/kg, while groundwater As ranged between 0.05 and 0.44 mg/L from adjoining water wells. Morphological and mineralogical studies of the aquifer sediments conducted using scanning electronic microscope energy-dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) analysis indicate the major presence of Fe- and Mn-oxyhydroxides. Sequential leaching experiments along with the mineralogical studies suggest that bacterially mediated, reductive dissolution of MnOOH and FeOOH is probably an important mechanism for releasing As into the groundwater from the sediments.

  11. Multiconfiguration electromagnetic induction survey for paleochannel internal structure imaging: a case study in the alluvial plain of the River Seine, France (United States)

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


    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.

  12. The groundwater balance in alluvial plain aquifer at Dehgolan, Kurdistan, Iran (United States)

    Amini, Ata; Homayounfar, Vafa


    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.

  13. Characterization of geomorphic units in the alluvial valleys and channels of Gulf Coastal Plain rivers in Texas, with examples from the Brazos, Sabine, and Trinity Rivers, 2010 (United States)

    Coffman, David K.; Malstaff, Greg; Heitmuller, Franklin T.


    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, described and characterized examples of geomorphic units within the channels and alluvial valleys of Texas Gulf Coastal Plain rivers using a geomorphic unit classification scale that differentiates geomorphic units on the basis of their location either outside or inside the river channel. The geomorphic properties of a river system determine the distribution and type of potential habitat both within and adjacent to the channel. This report characterizes the geomorphic units contained in the river channels and alluvial valleys of Texas Gulf Coastal Plain rivers in the context of the River Styles framework. This report is intended to help Texas Instream Flow Program practitioners, river managers, ecologists and biologists, and others interested in the geomorphology and the physical processes of the rivers of the Texas Gulf Coastal Plain (1) gain insights into how geomorphic units develop and adjust spatially and temporally, and (2) be able to recognize common geomorphic units from the examples cataloged in this report. Recent aerial imagery (high-resolution digital orthoimagery) collected in 2008 and 2009 were inspected by using geographic information system software to identify representative examples of the types of geomorphic units that occurred in the study area. Geomorphic units outside the channels of Texas Gulf Coastal Plain rivers are called \\"valley geomorphic units\\" in this report. Valley geomorphic units for the Texas Gulf Coastal Plain rivers described in this report are terraces, flood plains, crevasses and crevasse splays, flood-plain depressions, tie channels, tributaries, paleochannels, anabranches, distributaries, natural levees, neck cutoffs, oxbow lakes, and constructed channels. Channel geomorphic units occur in the river channel and are subject to frequent stresses associated with flowing water and sediment transport; they adjust (change) relatively quickly in

  14. Macroinvertebrate and diatom metrics as indicators of water-quality conditions in connected depression wetlands in the Mississippi Alluvial Plain (United States)

    Justus, Billy; Burge, David; Cobb, Jennifer; Marsico, Travis; Bouldin, Jennifer


    Methods for assessing wetland conditions must be established so wetlands can be monitored and ecological services can be protected. We evaluated biological indices compiled from macroinvertebrate and diatom metrics developed primarily for streams to assess their ability to indicate water quality in connected depression wetlands. We collected water-quality and biological samples at 24 connected depressions dominated by water tupelo (Nyssa aquatica) or bald cypress (Taxodium distichum) (water depths = 0.5–1.0 m). Water quality of the least-disturbed connected depressions was characteristic of swamps in the southeastern USA, which tend to have low specific conductance, nutrient concentrations, and pH. We compared 162 macroinvertebrate metrics and 123 diatom metrics with a water-quality disturbance gradient. For most metrics, we evaluated richness, % richness, abundance, and % relative abundance values. Three of the 4 macroinvertebrate metrics that were most beneficial for identifying disturbance in connected depressions decreased along the disturbance gradient even though they normally increase relative to stream disturbance. The negative relationship to disturbance of some taxa (e.g., dipterans, mollusks, and crustaceans) that are considered tolerant in streams suggests that the tolerance scale for some macroinvertebrates can differ markedly between streams and wetlands. Three of the 4 metrics chosen for the diatom index reflected published tolerances or fit the usual perception of metric response to disturbance. Both biological indices may be useful in connected depressions elsewhere in the Mississippi Alluvial Plain Ecoregion and could have application in other wetland types. Given the paradoxical relationship of some macroinvertebrate metrics to dissolved O2 (DO), we suggest that the diatom metrics may be easier to interpret and defend for wetlands with low DO concentrations in least-disturbed conditions.

  15. Integration of LiDAR and cropmark remote sensing for the study of fluvial and anthropogenic landforms in the Brenta-Bacchiglione alluvial plain (NE Italy) (United States)

    Ninfo, Andrea; Mozzi, Paolo; Abbà, Tiziano


    The geomorphological study of alluvial plains takes great advantage from the integration of detailed altimetry with high-resolution images, especially in the lower-relief sectors, like those in the distal plain of the Brenta and Bacchiglione rivers near the city of Padua (mean slope 1-0.8‰). The LiDAR data which were specifically acquired for this research (Riegl LMS-Q560, mean density 7 points/m2, overall area 123 km2), were classified and interpolated in order to map fluvial and anthropogenic landforms. The acquisition was carried out in a moment of minimal vegetation luxuriance (March 2011), in order to minimize ground cover. The DEM (z accuracy hand augerings and description of stratigraphic sections in pits, in order to validate the remote sensing interpretations. The detailed topography allowed the identification and mapping of low rise interfluves and scarps (morphology of the multi-stratified archeological mound in the historical center of Padua. The remote sensing of cropmarks is the most appropriate method to complete the mapping of the numerous fluvial forms that have little or no topographic expression being too small (i.e. minor crevasse channels and splays) and/or flattened by anthropogenic activity (mainly plowing). LiDAR intensity permitted a precise mapping of LGM deposits that have shown peculiar reflectivity related to specific soil characteristics (i.e., presence of calcic horizons in well-drained, elevated position). High resolution images and LiDAR DEM allow the analysis of this largely anthropized low-plain environment at cell-size scale of 0.5-1 m, i.e. approximating the original complexity of the alluvial sedimentary environment. The results bring advances in the comprehension of the Last Glacial Maximum and Holocene evolution of the Brenta-Bacchiglione plain. The large-scale mapping of paleohydrographic features led to the recognition of different fluvial styles adopted by the Brenta River: i) braided to wandering paleochannels, 100

  16. 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.


    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

  17. 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 (United States)

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


    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.

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

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    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)


    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 ({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)

  19. Coastal inundation risk assessment due to subsidence and sea level rise in a Mediterranean alluvial plain (Volturno coastal plain - southern Italy) (United States)

    Ciro Aucelli, Pietro Patrizio; Di Paola, Gianluigi; Incontri, Pietro; Rizzo, Angela; Vilardo, Giuseppe; Benassai, Guido; Buonocore, Berardino; Pappone, Gerardo


    Interdisciplinary studies of the last years highlight that the Italian coasts are significantly subject to retreat and to inundation by sea ingression due to natural and anthropic causes. In this study, the effects of future relative sea level have been evaluated for the Volturno River Plain, one of the widest coastal plain in southern Italy. The plain is characterized by high economical and ecological value, for the presence of farm activities, tourist structures and wetland protected zones. The study area is potentially prone to coastal flooding due to its very low topography and because it is affected by a severe subsidence, which emphasize the local effect of sea level rise due to the ongoing climate changes. In accordance with the guidelines of the MEDFLOOD project, the areas prone to inundation in the years 2065 and 2100 have been evaluated by comparing the future topographical information and expected relative sea level scenarios. The local Vertical Ground Displacements have been derived by PS-InSAR processing data whilst the mean values of the scenarios RCP 2.6 and RCP 8.5 provided by the IPCC (2014) have been used as future sea level projections in 2065 and 2100. The PS-InSar data elaboration shows that the area affected by subsidence corresponds to 35% of the Volturno plain and that the annual rate of the phenomenon ranges between -1 and -25 mm/yr. The inundation analysis, based on the classification of the areas in four hazard classes, indicates that in 2065 the zones located below the sea level will increase approximately of 50% respect to the present conditions, while between 2065 and 2100 the increase can be at least of 60% (IPCC, RCP 8.5 scenarios). Considering the socio-economical and ecological exposure, evaluated following the EUROSION project guidelines, the coastal flooding risk maps have been produced. Almost 8.2 km2 and 14.4 km2 of the investigated area has to be considered subject to very high marine inundation risk in 2065 and 2100

  20. 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.


    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

  1. Alluvial Aquifer (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...

  2. Detailed soil mapping and relationships between soil characteristics and tree growth in an alluvial plain (Lombardy, Italy) (United States)

    Ferré, Chiara; Comolli, Roberto


    The study area is located in an abandoned meander of the Oglio river (southern Lombardy, Italy), with young soils of alluvial origin (Calcaric Fluvisols). During 2002, in an area covering 20 hectares, a tree plant for wood production was realized (oak, hornbeam, ash, alder, and walnut; poplar only in the first part of the growth cycle). Objective of the study was to verify the existence of correlations between tree growth and soil characteristics. In 2004, the soil was sampled at 126 points, according to a regular grid, taking the surface soil horizon (Ap). The collected soil samples were analyzed in laboratory, measuring pH in H2O and KCl, texture, total carbonates, soil organic C (SOC), available P (Olsen), and exchangeable K. The pH in H2O varies between 7.7 and 8.1; the pH in KCl varies between 7.2 and 7.7; the more frequent particle-size classes are loam and sandy loam; SOC varies between 0.4 and 1.1%; total carbonates from 23 to 45%; exchangeable K between 0.01 and 0.25 cmol(+) kg-1; available P between 1.2 and 16.8 mg kg-1. At a distance of 12 years, in 2014, diameters at breast height of all the trees (2513 in total) were measured and their height was estimated on the basis of empirical equations obtained for each species, in order to calculate the tree volume. Spatial variability of soil properties was evaluated and mapped using multivariate geostatistical techniques. The analyses revealed the presence of different scales of spatial variation: micro-scale, short range scale (about 80 m for texture) and long range scale (about 220 m for texture). The spatial pattern of most soil properties (mainly texture and total carbonates) was probably associated with fluvial depositional processes. To evaluate soil-plant relationships, soil characteristics were collocated into the plant data set by estimating specific soil properties at each individual tree location. Soil spatial variability was reflected by the differences in plant growth. Statistical analysis of the

  3. Geo-enviromental analysis in the recent alluvial plains of the large menderes and the small menderes


    TAKAHASHI, Manabu


    In the recent alluvial plains of the Large Menderes and the Small Menderes, there were some harbor-cities called Priene, Milet, and Ephesos. Although these harbor-cities prospered during the ancient Greek period and the ancient Roman period, they have become ruins. These harbor-cities are now located far from the present coast, as the coastline has since moved dramatically. How did the coastline move at the historical period, why did it move, and how did the city residents cope with the ch...

  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 (United States)

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


    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

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    Alessandro Chiaudani


    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 residence times of hyporheic ground water in two alluvial flood plains of the Southern Alps using water temperature and tracers

    Directory of Open Access Journals (Sweden)

    E. Hoehn


    Full Text Available Water temperature can be used as a tracer for the interaction between river water and groundwater, interpreting time shifts in temperature signals as retarded travel times. The water temperature fluctuates on different time scales, the most pronounced of which are the seasonal and diurnal ones. While seasonal fluctuations can be found in any type of shallow groundwater, high-frequency components are more typical for freshly infiltrated river water, or hyporheic groundwater, and are thus better suited for evaluating the travel time of the youngest groundwater component in alluvial aquifer systems. We present temperature time series collected at two sites in the alpine floodplain aquifers of the Brenno river in Southern Switzerland. At the first site, we determine apparent travel times of temperature for both the seasonal and high-frequency components of the temperature signals in several wells. The seasonal signal appears to travel more slowly, indicating a mixture of older and younger groundwater components, which is confirmed by sulphate measurements. The travel times of the high-frequency component qualitatively agree with the groundwater age derived from radon concentrations, which exclusively reflects young water components. Directly after minor floods, the amplitude of temperature fluctuations in an observation well nearby the river is the highest. Within a week, the riverbed is being clogged, leading to stronger attenuation of the temperature fluctuations in the observation well. At the second site, very fast infiltration to depths of 1.9 m under the riverbed could be inferred from the time shift of the diurnal temperature signal.

  7. Fertilidade de alguns solos de várzea do vale do Paraíba Fertility of some soils in alluvial plains of the Paraíba valley

    Directory of Open Access Journals (Sweden)

    H. Garcia Blanco


    Full Text Available Com a finalidade de avaliar a fertilidade de alguns solos de várzea do vale do rio Paraíba, foram instalados ensaios em vasos com arroz, utilizando as séries Corruçá, Avareí e Brejão. A primeira é argilosa; a segunda, orgânica; a terceira, intermediária das anteriores, isto é, argilo-orgânica. Apesar de os resultados analíticos indicarem teores elevados em nutrientes, as reações às adubações foram intensas na maioria dos casos, induzindo à consideração de que os índices de fertilidade dos solos bem drenados não se aplicam a essas séries. Todos os solos apresentaram reação bastante pronunciada ao nitrogênio. No solo mineral argiloso, não se evidenciou reação ao potássio, mas sòmente a N e P. No argilo-orgânico, o P foi o único elemento que não reagiu. Finalmente, no solo orgânico, reagiram, além do N, os outros dois elementos.A study dealing with the fertility of three soils from alluvial plains in the Paraiba River Valley, State of São Paulo, was carried out in greenhouse tests, with rice (of the Iguape-agulha variety cultivated in pots of 6.0 kg soil capacity. The samples were collected down to 20 cm depth from the following monotype soils series: Corruçá, Brejão and Avareí. The former is an alluvial clay soil and the latter an organic one representing stratified muck and peat; the Brejão series is also organic soil but has an intermediate, organic and clay, texture. The experiment was designed to investigate these soils' needs for the NPK nutrients. In an extra treatment the needs for the minor elements were investigated too. The results obtained in these experiments indicated that the fertility levels based on chemical analyses and applied to fertilization practice to other well drained soils of the State are not satisfactory for the soils in question. A significant favorable response to nitrogen was shown by all the soils studied though they held high content of this element. The response to

  8. Alluvial Deposits in Iowa (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


    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


    The infiltration of atrazine, deethylatrazine, and deisopropylatrazine from Walnut Creek, a tributary stream, to the alluvial valley aquifer along the South Skunk River in central Iowa occurred where the stream transects the river's flood plain. A preliminary estimate indicated t...

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

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

    Emile S. Gardiner


    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. Basement and alluvial aquifers of Malawi: An overview of ...

    African Journals Online (AJOL)

    Elizabeth B Mapoma


    Feb 17, 2014 ... seeks to identify literature on Malawi's groundwater and use the same to summarize physico-chemical ... values in one paper that will act as a starting point when identifying references about groundwater ... away the weathering products; and, (4) The Rift valley floor (hosting the alluvial plain) located below ...

  14. Laboratory alluvial fans in one dimension. (United States)

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


    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.

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

  16. 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


    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)

  17. Vertisols in the Central Clay Plain of the Sudan

    NARCIS (Netherlands)

    Blokhuis, W.A.


    The Central Clay Plain is situated between latitudes 16° and 10° North and longitudes 32° and 37° East, in the Republic of the Sudan. The parent materials of the clay soils which cover almost this entire area belong to two broad groups: alluvial, deltaic and paludal sediments from rivers belonging

  18. High-resolution characterization of chemical heterogeneity in an alluvial aquifer (United States)

    Schulmeister, M.K.; Healey, J.M.; Butler, J.J.; McCall, G.W.; Birk, S.


    The high-resolution capabilities of direct push technology were exploited to develop new insights into the hydrochemistry at the margin of an alluvial aquifer. Hydrostratigraphic controls on groundwater flow and contaminant loading were revealed through the combined use of direct push electrical conductivity (EC) logging and geochemical profiling. Vertical and lateral variations in groundwater chemistry were consistent with sedimentary features indicated by EC logs, and were supported by a conceptual model of recharge along the flood plain margin.

  19. Response spectra in alluvial soils

    International Nuclear Information System (INIS)

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


    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)

  20. Utopia Plain (United States)


    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

  1. 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.


    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

  2. Holocene alluvial stratigraphy in the upper Susquehanna River Basin, New York*1 (United States)

    Scully, Richard W.; Arnold, Richard W.


    Two alluvial terraces and the present flood plain were studied at two locations along the Susquehanna and Unadilla Rivers in south-central New York state. They have formed since deglaciation and incision of the stream channels into the valley train deposits. The higher terrace has noncumulative soil profiles with well-developed color B horizons predominantly of silt loam and very fine sandy loam. The terrace is weathered to a degree similar to nearby glacial outwash terraces that have caps of similarly textured sediments. Incision that produced the terrace occurred before 9705 ± 130 yr B.P. The lower terrace is characterized by relatively thick, vertical-accretion deposits of silt loam that contain sequences of thin, buried A, color B, and C horizons. They were formed between about 3240 ± 110 ( 14C data of soil humin) and 235 ± 80 yr B.P. Deposits above the 235 ± 80 yr B.P. stratum are unweathered. The soil stratigraphy and 14C dates of soil humin from buried A horizons are surprisingly well correlated between sites. Most sediments of the present flood plain have been deposited since 1120 ± 80 yr B.P. Incipient A horizons and oxidation of inherited organic matter in the subsoil are the only evidence of pedogenesis in the flood-plain deposits that are older than 275 ± 80 yr B.P. The most recent flood-plain fill deposited since then is unaltered. These youngest sediments of the flood plain along with the youngest veneer of vertical-accretion deposits on the lowest terrace are associated with an increased rate of deposition largely attributable to clearing of the forests by settlers, beginning in the late 1700s. Comparison of the alluvial stratigraphy with the radiocarbon-dated pollen stratigraphy of southwestern New York (Miller 1973) reveals some apparent time correlations between alluvial events and vegetation changes. This gives reason to speculate that climatic change or forest catastrophes such as disease or drought are causes of some of the alluvial

  3. Major advances of soil and water conservation in the U.S. Southern Great Plains (United States)

    The U.S. Southern Great Plains comprise the broad expanse of prairie and steppe lands that lie east of the Rocky Mountains and cover parts of Colorado, Kansas, New Mexico, Oklahoma, and Texas where semi-arid dryland crop production merges into rainfed farming. Except for exposed Pliocene alluvial st...

  4. Characterization of land subsidence induced by groundwater withdrawals in Wenyu River alluvial fan, Beijing, China

    Directory of Open Access Journals (Sweden)

    R. Wang


    Full Text Available The Beijing plain area has suffered from severe land subsidence owing to groundwater overdraft. A major example is the Wenyu River alluvial fan in the Beijing plain area. This area has experienced as much as 10 m of land subsidence through 2000s. An integrated subsidence-monitoring program, including borehole extensometer and multilayer monitoring of groundwater, has been designed to meet the needs of monitoring land subsidence in this region. This work has allowed us to characterize land subsidence and understand the mechanical properties of the strata. The analysis results show the development of the land subsidence in this area is consistent with water-level change. The major strata contributing to compression deformation are Mid-Pleistocene stratum which contributed around 70 % of total subsidence. The shallow stratum and deep stratum show elastic mechanical behavior the intermediate stratum exhibit elastic-plastic mechanical behavior.

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Handford, C.R.


    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.

  7. Long-term interactions between man and the fluvial environment - case of the Diyala alluvial fan, Iraq (United States)

    Heyvaert, Vanessa M. A.; Walstra, Jan; Mortier, Clément


    The Mesopotamian alluvial plain is dominated by large aggradading river systems (the Euphrates, Tigris and their tributaries), which are prone to avulsions. An avulsion can be defined as the diversion of flow from an existing channel onto the floodplain, eventually resulting in a new channel belt. Early civilizations depended on the position of rivers for their economic survival and hence the impact of channel shifts could be devastating (Wilkinson 2003; Morozova 2005; Heyvaert & Baeteman 2008). Research in the Iranian deltaic part of the Mesopotamian plain has demonstrated that deliberate human action (such as the construction of irrigation canals and dams) triggered or obstructed the alluvial processes leading to an avulsion on fluvial megafans (during preconditioning, triggering and post-triggering stages) (Walstra et al. 2010; Heyvaert et al. 2012, Heyvaert et al.2013). Thus, there is ample evidence that the present-day alluvial landscapes in the region are the result of complex interactions between natural and anthropogenic processes. Here we present a reconstruction of the Late Holocene evolution of the Diyala alluvial fan (one of the main tributaries of the Tigris in Iraq), with particular attention to the relations between alluvial fan development, changes in channel pattern, the construction of irrigation networks and the rise and collapse of societies through historic times. The work largely draws on the use of remote sensing and GIS techniques for geomorphological mapping, and previously published archaeological field data (Adams 1965). By linking archaeological sites of known age with traces of ancient irrigation networks we were able to establish a chronological framework of alluvial activity of the Diyala alluvial fan. Our results demonstrate that centralized and technologically advanced societies were able to maintain a rapidly aggradading distibutary channel system, supplying water and sediment across the entire alluvial fan. As a consequence

  8. Reconstruction of a daily flow record along a hydrologically complex alluvial river (United States)

    Rupp, David E.; Larned, Scott T.; Arscott, David B.; Schmidt, Jochen


    SummaryComplex spatial and temporal flow patterns in alluvial plain rivers can be caused by variation in groundwater surface-water exchange, channel planform, and climatic variation. Such complexity poses a challenge for developing relationships between runoff, groundwater recharge, and river flow, for predicting effects of water resource developments, and for understanding hydrologic effects on ecological processes. The Selwyn River of New Zealand is one such hydrologically complex river. To begin to understand the spatio-temporal flow patterns of the Selwyn River, we used linear and logistic models to reconstruct a 22-yr record of river flow across the alluvial Canterbury Plains. The 60 km - long model domain encompasses perennial, ephemeral, and intermittent reaches embedded within larger effluent and influent sections. Flow at 18 cross-sections distributed along the river mainstem was modelled as a function of flow at stage recorders located at each end of the domain with flow interpolated between cross-sections to generate a flow record continuous in space. Data from 38-months of flow-gauging at the cross-sections was used to calibrate model parameters. The reconstructed record indicates that while the central section of the river was dry during most of the 38-month observation period, it was not uncommon during the preceding two decades for the river to flow along its entire course for several months consecutively. The recent dry period may be part of a longer trend: the mean annual simulated length of dry river channel has increased by 0.6 km yr -1 over the last two decades. Output metrics from the model can increase our understanding of hydrologic control of ecological processes in alluvial rivers. We provide several examples of potential model applications to ecological studies.

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

    Directory of Open Access Journals (Sweden)

    Wotchoko Pierre


    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.

  10. Exploring geothermal structures in the Ilan Plain, Taiwan (United States)

    Wang, Chien-Ying; Shih, Ruey-Chan; Chung, Chen-Tung; Huang, Ming-Zi; Kuo, Hsuan-Yu


    The Ilan Plain in northeast Taiwan is located at the southwestern tip of the Okinawa Trough, which extends westward into the Taiwan orogeny. The Ilan Plain covered by thick sediments is clipped by the Hsuehshan Range in the northern side and the Central Range in the southern side. High geothermal gradients with plenteous hot springs of this area may result from igneous intrusion associated with the back-arc spreading of the Okinawa Trough. In this study, we use reflection seismic survey to explore underground structures in the whole Ilan Plain, especially in SanShin, Wujie, and Lize area. We aim to find the relationship between underground structures and geothermal forming mechanism. The research uses reflection seismic survey to investigate the high geothermal gradient area with two mini-vibrators and 240-channel system. The total length of seismic lines is more than 30 kilometers. The results show that alluvial sediments covering the area about 400 600 meters thick and then thin out to the west in SanShin area. In SanShin , the Taiyaqiao anticline in Hsuehshan Range has entered the plain area and is bounded by the Zhuoshui fault (south) and the Zailian fault (north). In Wujie and Lize , Zhuoshui fault cut through a strong reflector which is the top of the gravel layer near the bottom of the alluvial layer, while the SanShin fault seems to cut near very shallow strata. These two faults are a strike-slip fault with a bit of normal fault component distributing over a range of 600 meters. In Ilan Plain, the geothermal forming mechanism is controlled by anticlines and faults. The hydrothermal solution which migrates upward along these anticline or fault zones to the shallow part causing high geothermal gradients in these areas.

  11. Northern Plains Buried Craters (United States)


    22 December 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows three circular features on the martian northern plains near 70.7oN, 311.7oW. These circular features are the locations of meteor impact craters that have been buried beneath the plains. Much of the northern plains shares this story, in which thousands of old craters have been filled or partially filled and then thinly buried beneath textured plains. The picture covers an area 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  12. Basement and alluvial aquifers of Malawi: An overview of ...

    African Journals Online (AJOL)

    This paper highlights the quality of groundwater in basement and alluvial aquifers of Malawi through literature assessment. Groundwater in these aquifers serves about 60% of Malawian population. Alluvial aquifers yield high groundwater in excess of 10 L/s and more mineralized than basement aquifers. The values from ...

  13. Evaluation of carbaryl sorption in alluvial soil

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal


    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.

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

    Mandel, R.D.


    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. 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.


    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

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

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

    International Nuclear Information System (INIS)

    French, R.H.


    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

  18. Radon concentration in the springs of the alluvial fan

    International Nuclear Information System (INIS)

    Horiuchi, Kimiko; Ishii, Tadashi; Kobayashi, Masao


    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)

  19. 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.


    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

  20. The role of rivers in ancient societies, or how man transformed the alluvial landscapes of Khuzestan (SW Iran) (United States)

    Walstra, J.; Heyvaert, V.; Verkinderen, P.


    For many thousands of years the alluvial plains of Khuzestan (SW Iran) have been subject to intensive settlement and agriculture. Ancient societies depended on the position of major rivers for their economic survival and hence, there is ample evidence of human activities trying to control the distribution of water. Throughout the plains ancient irrigation and settlement patterns are visible, although traces are rapidly disappearing due to expanding modern land use. Aim of this study is to unlock and integrate the rich information on landscape and archaeology, which only survives through the available historical imagery and some limited archaeological surveys. A GIS-based geomorphological mapping procedure was developed, using a variety of imagery, including historical aerial photographs, CORONA, Landsat and SPOT images. In addition, supported by the evidence from previous geological field surveys, archaeological elements were identified, mapped and included in a GIS database. The resulting map layers display the positions of successive palaeochannel belts and extensive irrigation networks, together indicating a complex alluvial history characterized by avulsions and significant human impact. As shown in several case-studies, integrating information from multiple disciplines provides valuable insights in the complex landscape evolution of this region, both from geological and historical perspectives. Remote sensing and GIS are essential tools in such a research context. The presented work was undertaken within the framework of the Interuniversity Attraction Pole "Greater Mesopotamia: Reconstruction of its Environment and History" (IAP 6/34), funded by the Belgian Science Policy.

  1. The sedimentary record of Carboniferous rivers: Continuing influence of land plant evolution on alluvial processes and Palaeozoic ecosystems (United States)

    Davies, Neil S.; Gibling, Martin R.


    Evidence from modern rivers and the deep-time geological record attests to the fundamental importance of plant life for the construction of physical habitats within fluvial environments. Data from an extensive literature review and original fieldwork demonstrates that many landforms and geomorphic features of modern river systems appear in the Palaeozoic stratigraphic record once terrestrial vegetation had adopted certain evolutionary advances. For example, stable point bars are associated with the onset of rooted plants in the Siluro-Devonian and avulsive and anabranching fluvial systems become common at the same time as extensive arborescent vegetation in the Carboniferous. In this paper, we demonstrate a correlation between the diversification of physical fluvial environments and the expansion of terrestrial fauna and flora, with an emphasis on the culmination of these trends within Carboniferous alluvial systems. Many extrinsic factors have been considered as possible controls on the evolutionary timelines of terrestrialization for organisms. However, a fundamental prerequisite for achieving terrestrial biodiversity was the variety of physical habitats, especially riparian systems, available for newly evolved organisms. In association with abundant lowland meandering systems, the widespread appearance across Carboniferous alluvial plains of fixed-channel and anabranching reaches created further physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes. Furthermore the associated increase in arborescent vegetation and supply of large woody debris to inland and coastal rivers would have created a wealth of microhabitats for continental organisms. We argue that the expanding extent and diversity of physical alluvial niches during the Palaeozoic is an underappreciated driver of the terrestrialization of early continental life. The study of the deep-time fossil and stratigraphic record also illustrates that vegetation is

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

    Energy Technology Data Exchange (ETDEWEB)

    Langraf, B.


    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.

  3. Designing the Alluvial Riverbeds in Curved Paths (United States)

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


    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.

  4. The Plains of Venus (United States)

    Sharpton, V. L.


    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

  5. Northern Plains 'Crater' (United States)


    10 December 2004 The lower left (southwest) corner of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the location of a somewhat filled and buried meteor impact crater on the northern plains of Mars. The dark dots are boulders. A portion of a similar feature is seen in the upper right (northeast) corner of the image. This picture, showing landforms (including the odd mound north/northeast of the crater) that are typical of the martian northern lowland plains, was obtained as part of the MGS MOC effort to support the search for a landing site for the Phoenix Mars Scout lander. Phoenix will launch in 2007 and land on the northern plains in 2008. This image is located near 68.0oN, 227.4oW, and covers an area approximately 3 km (1.9 mi) wide. The scene is illuminated by sunlight from the lower left.

  6. Geomorphology and flood-plain vegetation of the Sprague and lower Sycan Rivers, Klamath Basin, Oregon (United States)

    O'Connor, James E.; McDowell, Patricia F.; Lind, Pollyanna; Rasmussen, Christine G.; Keith, Mackenzie K.


    This study provides information on channel and flood-plain processes and historical trends to guide effective restoration and monitoring strategies for the Sprague River Basin, a primary tributary (via the lower Williamson River) of Upper Klamath Lake, Oregon. The study area covered the lower, alluvial segments of the Sprague River system, including the lower parts of the Sycan River, North Fork Sprague River, South Fork Sprague River, and the entire main-stem Sprague River between the confluence of the North Fork Sprague and the South Fork Sprague Rivers and its confluence with the Williamson River at Chiloquin, Oregon. The study included mapping and stratigraphic analysis of flood-plain deposits and flanking features; evaluation of historical records, maps and photographs; mapping and analysis of flood-plain and channel characteristics (including morphologic and vegetation conditions); and a 2006 survey of depositional features left by high flows during the winter and spring of 2005–06.

  7. Tietkens Plain karst - Maralinga

    International Nuclear Information System (INIS)

    James, J.M.


    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

  8. Factor analysis on land subsidence in the Nobi Plain, southwest Japan

    Directory of Open Access Journals (Sweden)

    A. Kouda


    Full Text Available The land subsidence of the Nobi Plain largely ceased with the commencement of pumping regulations beginning in 1975. However, a small amount of land subsidence, less than one centimeter, is still observed at the Delta zone in the southwest part of the Plain. The authors attempted to investigate the cause of the small amount of existing subsidence. The alluvial clay layer deposits are more than 15–20 m thick and the withdrawal is small. The decrease of the yearly average groundwater level has not been confirmed. On the other hand, the seasonal change in the groundwater level is clearly observed. This investigation focuses on the seasonal change of groundwater level each year and its relation to the thickness of alluvial clay layer. The Delta zone was divided into several cells and a multiple regression analysis was applied to the seasonal change of the groundwater level and the thickness of alluvial clay layer of the cell. The study concluded that the small amount of land subsidence was caused of drawdown of piezometric head of groundwater every year during the summer.

  9. Cracked Plain, Buried Craters (United States)


    4 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a cracked plain in western Utopia Planitia. The three circular crack patterns indicate the location of three buried meteor impact craters. These landforms are located near 41.9oN, 275.9oW. The image covers an area approximately 3 km (1.9 mi) across. Sunlight illuminates this scene from the lower left.

  10. Modelling the response of an alluvial aquifer to anthropogenic and ...

    Indian Academy of Sciences (India)

    ... stream system regionally. Similarly, a severe drought would lead to a total streamflow loss of < 80%. A post-audit of the model was also carried out to evaluate model performance. By simulating various stress scenarios on the alluvial aquifer, this study provides important information for evaluating management options for ...

  11. Economic Mineral Potentials Of Tailing Dumps From Alluvial Mining ...

    African Journals Online (AJOL)

    Several tonnes of mine tailing dumps abound in the alluvial tin mining areas of the Jos Plateau. These tailings are considered low in contents of cassiterite, columbite, tantalite, zircon and other minerals normally won from tin mining. Four of these dumps in four different mines located in Barkin Ladi (BL), Gurum (GM), Sabon ...

  12. Modelling the response of an alluvial aquifer to anthropogenic and ...

    Indian Academy of Sciences (India)

    This paper uses Visual MODFLOW to simulate potential impacts of anthropogenic pumping and recharge variability on an alluvial ..... hydraulic conductivity (K) over the aquifer, active cells in model layer 1 were initially ..... groundwater elevation at two observation wells (transient) (adapted from Zume and Tarhule 2006).

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

    DEFF Research Database (Denmark)

    Jain, M.; Tandon, S.K.


    /chlorite and smectite/illite of the alluvial palaeosols have been used as proxy indicators of climate change. These indicate wet phases during the OIS 5 and OIS 1. The overall stratigraphic development is discussed in the framework of fluvial response to climate change during the Late Pleistocene....

  14. Occurrence of volcanic ash in the Quaternary alluvial deposits, lower ...

    Indian Academy of Sciences (India)

    This communication reports the occurrence of an ash layer intercalated within the late Quaternary alluvial succession of the Madhumati River, a tributary of the lower Narmada River. Petrographic, morphological and chemical details of glass shards and pumice fragments have formed the basis of this study. The ash has ...

  15. Reworked calcretes: their significance in the reconstruction of alluvial sequences (Permian and Triassic, Minorca, Balearic Islands, Spain) (United States)

    Gómez-Gras, D.; Alonso-Zarza, A. M.


    The Permian and Triassic of Minorca (Balearic Islands) consists of a 670-m-thick, red, alluvial succession that includes in situ calcrete profiles and reworked calcrete material. In the Permian succession, the calcretes vary from laminar forms developed on the Carboniferous basement to weakly developed nodular calcretes in fluvial sediments. The palaeosols in the Triassic are mostly dolomitic, and the profiles reach up to Stage III of soil development (Spec. Pap.-Geol. Surv. Am. 203, (1995) 1). The clasts, formed through reworking of the palaeosol profiles, are about 0.5-10 cm across and include mosaics of calcite/dolomite crystals, brecciated clasts, rhizolith fragments, and aggregates of clay and/or silt. These clasts appear in three different types of deposits. Type 1 corresponds to lenticular bodies that fill small scour surfaces, and consists only of intraformational conglomerates. These deposits are interpreted as ephemeral channels and sheet-floods that represent the interfluvial drainage systems that captured only the precipitation falling on the alluvial plain. Type 2 includes sand dune 3-D bodies with flat bottoms and convex tops. These bodies are about 20 cm high and 2 m wide, and were formed by floodwaters that flowed down the levees of the major streams. Type 3 channel deposits contain reworked calcretes and extrabasinal clasts, which overlie erosive surfaces and are found in layers within cross-bedded sandstones and conglomerates. These are interpreted as channel-floor lag deposits of major channels that entered from distant uplands and drained the alluvial plain. Variations in the aggradation rates of the floodplain resulted in five different infill stages. In the lowstand to early transgressive interval, as in stages I (P1) and IV (B1), the fluvial deposits filled palaeovalleys; calcretes and reworked calcrete deposits were of difficult formation (apart from terraces) and preservation. Accommodation space was at its greatest in the transgressive

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

    Directory of Open Access Journals (Sweden)

    Ahmet Sami Erol


    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

  17. Correlation of alluvial deposits at the Nevada Test Site

    International Nuclear Information System (INIS)

    Grothaus, B.; Howard, N.


    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

  18. Lateral groundwater inflows into alluvial aquifers of main alpine valleys (United States)

    Burger, Ulrich


    In alpine regions the topography is mainly characterised by deep incised valleys, mountain slopes and ridges. Usually the main valleys contain aquifers in alluvial soft rock. Lateral these aquifers are confined by mountainous hard rock slopes covered by heterogeneous sediments with different thickness. The slopes can be incised by lateral valleys. Numerical models for the main alluvial aquifers ask for lateral hydrogeological boundaries. Usually no flow boundaries or Constant head Boundaries are used, even if the lateral inflows to the main aquifers are rarely known. In this example a data set for a detailed investigated and monitored area is studied to give an answer on the location and the quantification of these lateral subsurface inflows. The study area is a typical main alpine valley with a thick alluvial aquifer (appr. 120m thick), lateral confined by granite, covered at the base of the steep slopes by quaternary sediments (Burger at al. 2012). The study consists of several steps 1.) Analytical calculation of the inflows on the base of investigated and monitored 2d profiles along fault zones (Perello et al 2013) which pinch out in the main valley 2.) Analytical models along typical W-dipping slopes with monitored slope springs 3.) Evaluating temperature and electrical conductivity profiles measured in approx. 30 groundwater wells in the alluvial aquifers and along the slopes to locate main lateral subsurface inflows 4.) Output of a regional model used for the hydrogeological back analyses of the excavation of a tunnel (Baietto et al. 2014) 5.) Output of a local numerical model calibrated with a monitoring dataset and results of a pumping test of big scale (450l/s for 10days) Results of these analyses are shown to locate and quantify the lateral groundwater inflows in the main alluvial aquifer. References Baietto A., Burger U., Perello P. (2014): Hydrogeological modelling applications in tunnel excavations: examples from tunnel excavations in granitic rocks

  19. The use of O, H and Sr isotopes and carbamazepine to identify the origin of water bodies supplying a shallow alluvial aquifer (United States)

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


    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


    Directory of Open Access Journals (Sweden)

    C. Grigoras


    Full Text Available The Vinga Plain, a unit of the Banato – Crişane Plain, is a piedmont terrace plain covered by a thick layer of loess and loess-like deposits. The soil cover belongs to seven classes and many soil types and sub-types. The utilization of the Romanian System of Soil Taxonomy new criteria of classification brought to the modification of most of the soils names, to the change of certain soils from one class to another or to the appearance of new types and subtypes. The modifications on the soils map are more important than these modifications. Here, some soil units were included in other units (the former alluvial gleyic soils are now to be found in the Fluvisols class or there appeared new units due to the separation of new soil types and sub-types (the former units of the illuvial clay chernozems were sheared between argic chernozems and argic phaeozems.

  1. Development of A Mississippi River Alluvial Aquifer Groundwater Model (United States)

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


    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.

  2. Alluvial Diamond Resource Potential and Production Capacity Assessment of Ghana (United States)

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


    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

  3. Rehabilitation of alluvial lands after open cut mining

    Energy Technology Data Exchange (ETDEWEB)



    Development consent for Coal & Allied's Hunter Valley Operations required completion of open cut mining to be followed up with rehabilitation and reinstatement of 63 hectares of land to class 1 and 2 cropping capacity by growing lucerne. The alluvial lands were backfilled with overburden, manured and sown with Aurora and Pioneer varieties and an irrigation system was installed in 2003. Drought conditions and prevalence of the white fringed weevil led to decreased yields but in February 2008 the lucerne productivity performance complied with the completion criteria. 2 photos.

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

  5. Evaluation of Main Compositions of Water Chemistry Data By Graphical Methods, Edremit (Balikesir) Alluvial Aquifer System (United States)

    Ertekin, Can; Sedat Çetiner, Ziya


    This case study aims to characterize and compare hydrogeochemistry based on major ion composition belonging to the year of 1970's, 2007 and 2008 for Edremit alluvial aquifer system which lies on the northwestern coast of Anatolia. Graphical representations including Piper, Schoeller, Stiff and Durov diagrams are applied to ease a systematic interpretation of a wide range of well chemistry data sets. In Piper diagram, water types of the aquifer system are mainly dominated with calcium, carbonate-bicarbonate and sulphate ions. Water types of the site are separated as sulphate or carbonate-bicarbonate ion dominated zones for 1970's data. Comparing data of 1970's, 2007 and 2008 the newest data set is clustered into magnesium dominate zone. This is related to relatively deep groundwater chemistry affect probably resulting from long term groundwater withdrawal for irrigation in the aquifer system. The Schoeller diagram portrays differences of the data set of 1970's, 2007 and 2008 more clearly comparing the Piper diagram. In this diagram, higher portions of magnesium and sulphate composition of the well data belonging to the year of 2007 and 2008 are possibly related to deep routes of groundwater flow paths of the site and/or geothermal water mixing. In Durov diagram, the data set was projected to a rectangular shape and it was not immediately clear to differentiate ionic composition of the water. This is not coincidence because the fact that pH values do not change significantly over the years and its contribution is not substantial comparing to major ion chemistry. Finally, application of hydrogeochemical modeling as a further step was touched upon herein to further depict undergone processes and end-members in the whole aquifer system on Edremit Plain. Keywords: Edremit, groundwater, aquifer, hydrogeochemistry, facies

  6. Analysis of cutin and suberin biomarker patterns in alluvial sedi-ments (United States)

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


    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.

  7. Tectonic controls on the geomorphic evolution of alluvial fans in the ...

    Indian Academy of Sciences (India)

    The Piedmont Zone has formed as a result of coalescing alluvial fans,alluvial aprons and talus deposits.The fans have differential morphologies and aggradation processes within a common climatic zone and similar litho-tectonic setting of the catchment area. Morphotectonic analysis reveals that the fan morphologies and ...

  8. Alluvial plain dynamics and human occupation in SW Amazonia during the Holocene: A paleosol-based reconstruction (United States)

    Lombardo, Umberto; Rodrigues, Leonor; Veit, Heinz


    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.

  9. Identification of regional soil quality factors and indicators: a case study on an alluvial plain (central Turkey) (United States)

    Şeker, Cevdet; Hüseyin Özaytekin, Hasan; Negiş, Hamza; Gümüş, İlknur; Dedeoğlu, Mert; Atmaca, Emel; Karaca, Ümmühan


    Sustainable agriculture largely depends on soil quality. The evaluation of agricultural soil quality is essential for economic success and environmental stability in rapidly developing regions. In this context, a wide variety of methods using vastly different indicators are currently used to evaluate soil quality. This study was conducted in one of the most important irrigated agriculture areas of Konya in central Anatolia, Turkey, to analyze the soil quality indicators of Çumra County in combination with an indicator selection method, with the minimum data set using a total of 38 soil parameters. We therefore determined a minimum data set with principle component analysis to assess soil quality in the study area and soil quality was evaluated on the basis of a scoring function. From the broad range of soil properties analyzed, the following parameters were chosen: field capacity, bulk density, aggregate stability, and permanent wilting point (from physical soil properties); electrical conductivity, Mn, total nitrogen, available phosphorus, pH, and NO3-N (from chemical soil properties); and urease enzyme activity, root health value, organic carbon, respiration, and potentially mineralized nitrogen (from biological properties). According to the results, the chosen properties were found as the most sensitive indicators of soil quality and they can be used as indicators for evaluating and monitoring soil quality at a regional scale.

  10. Characterization of Water Quality in Unmonitored Streams in the Mississippi Alluvial Plain, Northwestern Mississippi, May-June 2006 (United States)

    Bryson, Jeannie R.; Coupe, Richard H.; Manning, Michael A.


    The Mississippi Department of Environmental Quality is required to develop restoration and remediation plans for water bodies not meeting their designated uses, as stated in the U.S. Environmental Protection Agency's Clean Water Act section 303(d). The majority of streams in northwestern Mississippi are on the 303(d) list of water-quality limited waters. Agricultural effects on streams in northwestern Mississippi have reduced the number of unimpaired streams (reference streams) for water-quality comparisons. As part of an effort to develop an index to assess impairment, the U.S. Geological Survey collected water samples from 52 stream sites on the 303(d) list during May-June 2006, and analyzed the samples for nutrients and chlorophyll. The data were analyzed by trophic group as determined by total nitrogen concentrations. Seven constituents (nitrite plus nitrate, total Kjeldhal nitrogen, total phosphorus, orthophosphorus, total organic carbon, chlorophyll a, and pheophytina) and four physical property measurements (specific conductance, pH, turbidity, and dissolved oxygen) were determined to be significantly different (p indicators of stream productivity with which to infer stream health. Streams having high total Kjeldhal nitrogen values and high turbidity values along with low dissolved oxygen concentrations were typically eutrophic abundant in nutrients), whereas streams having low total Kjeldhal nitrogen values and low turbidity values along with high dissolved oxygen concentrations were typically oligotrophic (deficient in nutrients).


    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  12. River terraces and alluvial fans: The case for an integrated Quaternary fluvial archive (United States)

    Mather, A. E.; Stokes, M.; Whitfield, E.


    The fluvial archive literature is dominated by research on river terraces with appropriate mention of adjacent environments such as lakes. Despite modern sedimentary basins comprising a significant (>88%) volume of distributive fluvial systems, of which alluvial fans (>1 km, model is proposed to summarise the dynamic role of alluvial fans within this landscape context. The alluvial fans act as potential 'buffers' between hillslopes and river terrace records under 'top down' climate-driven high sediment supply and alluvial fan aggradation, and 'couplers' during periods of less sediment (in relation to water) discharge and alluvial fan incision. These dynamics will change with the addition of 'bottom up' controls such as main river incision, which will typically enhance the coupling effect of both systems.

  13. Evaluation of hydrologic conditions and nitrate concentrations in the Rio Nigua de Salinas alluvial fan aquifer, Salinas, Puerto Rico, 2002-03 (United States)

    Rodriguez, Jose M.


    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

  14. Sustainable Water Use System of Artesian Water in Alluvial Fan (United States)

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


    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

  15. A Surficial Hydrogeologic Framework for the Mid-Atlantic Coastal Plain (United States)

    Ator, Scott W.; Denver, Judith M.; Krantz, David E.; Newell, Wayne L.; Martucci, Sarah K.


    Sands and Gravels (Subregion 5) are relatively homogeneous in terms of hydrogeology, although an examination of results from small-scale studies within the Coastal Plain demonstrates that even these areas are quite variable, locally. Moderate topographic relief and primarily permeable surficial sediments promote good drainage of the land surface in Subregion 4, for example, but drainage is commonly poor in the Coastal Lowlands (Subregion 1) due to flat topography and low elevations. Agriculture is common in both subregions, although artificial drainage is typically required to support cultivation in Subregion 1. Important physiographic differences are evident among the remaining three subregions, although sediment textures within the Middle Coastal Plain Mixed Sediment Texture (Subregion 2), the Inner Coastal Plain Dissected Outcrop Belt (Subregion 6), and the Alluvial and Estuarine Valleys (Subregion 7) are variable even at the regional scale.

  16. 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)



    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.

  17. 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.


    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.)

  18. Preliminary geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California (United States)

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Stone, Paul; Powell, Charles L.; Gurrola, Larry D.; Selting, Amy J.; Brandt, Theodore R.


    Ynez Mountains indicate the potential for continued slope failures and mass movements that may threaten urbanized parts of the coastal plain. Deformed sedimentary rocks in the subsurface of the coastal plain and the adjacent Santa Barbara Channel contain deposits of oil and gas, some of which are currently being extracted. Shallow, localized sedimentary aquifers underlying the coastal plain provide limited amounts of water for the urban areas, but the quality of some of this groundwater is compromised by coastal salt-water contamination. The present map compilation provides a set of uniform geologic digital coverages that can be used for analysis and prediction of these and other geologic hazards and resources in the coastal plain region. In the map area the oldest stratigraphic units consist of resistant Eocene to Oligocene marine and terrestrial sedimentary rocks that form a mostly southward-dipping and laterally continuous sequence along the south flank of the Santa Ynez Mountains. Less resistant, but more variably deformed, Miocene, Pliocene, and Pleistocene marine sedimentary rocks and deposits are exposed in the lower Santa Ynez foothills and in the coastal hills and sea cliffs farther south. Pleistocene and Holocene surficial alluvial, colluvial, estuarine, and marine-terrace deposits directly underlie much of the low-lying coastal plain area, and similar-aged alluvial and landslide deposits locally mantle the lower flanks of the Santa Ynez Mountains. Structurally, the Santa Barbara coastal plain area is dominated by the Santa Barbara fold and fault belt, an east-west-trending zone of Quaternary, partly active folds and blind and exposed reverse and thrust faults. The dominant trend of individual structures within the belt is west-northwest -- slightly oblique to the overall trend of the fold and fault belt. A conspicuous exception, however, is the More Ranch fault system, which strikes east-northeast across the fold and f

  19. 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.

  20. 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.


    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.

  1. 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.


    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

  2. 49 CFR 229.64 - Plain bearings. (United States)


    ... 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...

  3. Evaluation of the applicability of the SWAT model in an arid piedmont plain oasis. (United States)

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


    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.

  4. A Numerical Model of Retreating Alluvial Fan Coasts (United States)

    Hicks, M.; Dickson, M.; Coco, G.


    A numerical model has been developed that simulates the wave-driven retreat of partially-consolidated alluvial- fan shores over millennium time-scales. It has been developed to reproduce the shore profiles and coastal erosion rates observed along the Pleistocene glacial-outwash fan built by the Waitaki River on the east coast of New Zealand's South Island. This cliffed shore is currently fronted by a narrow sand-and-gravel beach. The nearshore seabed is formed in Pleistocene substrate and has only a thin and patchy cover of sand. The motivation is to examine the sensitivity of the erosion rates to wave-climate change, sea-level rise, and river sediment supplies. The model is forced by two wave conditions that, when randomly sampled, represent the storm-wave and normal-swell climates of the prototype coast. These each operate for a fixed proportion of the model's yearly time-step. Morphological change is driven by a series of coupled process models. These include scour of the nearshore seabed by shoaling waves, cross-shore exchanges of sand and gravel between the nearshore and beach, berm construction during normal wave conditions, berm overtopping by storm waves with consequent beach stripping and scour of the exposed sub-aerial substrate and cliff-toe notch-cutting, gravity-failure of the cliffs and talus construction between storm events, and beach sediment abrasion. The scour, notching, and transport models are generally based on energetics principles and are calibrated with linear scaling coefficients to match field observations from the prototype coast. Negative feedback regulates the rate of cliff erosion through the protection that is afforded by cliff and substrate material added to the beach. The starting model condition is a sloping alluvial fan inundated by the sea-level rise that followed the last glacial epoch, and the model is run for 6000 years to the present assuming a stable sea level. Initially, the gentle slope of the alluvial fan results in

  5. The Effect of Geomorphic Complexity on Water Temperature in a Pacific Northwest Alluvial River (United States)

    Arrigoni, A. S.; Poole, G. C.; Thomas, S. A.; Woessner, W. W.; Mertes, L. A.; Boer, B. R.; O'Daniel, S. J.


    Hyporheic exchange of ground and surface water is an important physical process that contributes to the habitat template of alluvial rivers and is known to increase thermal diversity within streams by creating localized or isolated pockets where water temperature is buffered. Although the Umatilla River in northeastern Oregon, USA once supported healthy populations of salmonids (trout, salmon, and charr), summertime water temperatures in the river are now stressful or lethal to salmonids, exceeding 26° C. Using funding from NASA, the Confederated Tribes of the Umatilla Indian Reservation are coordinating the Data Rich Decision Support Environment research project to study the hydrologic and thermal regime of the river. As part of that study, we are documenting the influence of near-channel hyporheic exchange on the river's thermal regime. We instrumented a variety of stream channel units (pools, riffles, spring channels, etc.) and gravel bars with more than 70 temperature loggers. These were used to describe the thermal diversity of the channel and hyporheic zone in geomorphically complex settings where hyporheic exchange is prevalent. The loggers were deployed over a 4-week period during July and August. To monitor surface water temperatures loggers were attached to rebar that was pounded into the stream bed. For monitor hyporheic water temperatures loggers were placed in piezometers set 15 cm to 2 m into gravels . A total station was used to survey bar and streambed topography along with the locations of the temperature loggers. Resulting data suggest that complex channel patterns and bed-forms create hydraulic gradients within the near-channel aquifer that enhance hyporheic exchange. In addition to creating the expected localized patterns of thermal diversity in the stream channel near upwelling water, our data suggest that the cumulative affect of geomorphically complex nodes within the river have the ability to buffer diel temperature variation in the main

  6. Biodegradation of Petroleum Hydrocarbon Vapors In Unsaturated Alluvial Sand (United States)

    Höhener, P.; Duwig, C.; Pasteris, G.; Dakhel, N.; Kaufmann, K.; Werner, D.

    Biodegradation rates are critical parameters in models aimed at predicting the nat- ural attenuation of volatile organic compounds (VOCs) in the unsaturated zone. In this study the kinetic rate laws for the aerobic biodegradation of selected petroleum hydrocarbons and MTBE were investigated in unsaturated alluvial sand exposed to the vapors from a fuel mixture. Laboratory column and batch experiments were per- formed at room temperature under aerobic conditions. An analytical reactive transport model for VOC vapors in soil based on Monod kinetics is used for data interpretation. In the column experiment, steady-state diffusive vapor transport was reached after 23 days. Monod kinetic parameters were derived from the column profiles for toluene, m-xylene, octane and hexane. The degradation of cyclic alkanes, isooctane, and 1,2,4- trimethylbenzene was best described by first-order kinetics. MTBE, pentane and chlo- rofluorocarbons were recalcitrant. Batch experiments suggested first-order disappear- ance rate laws for all VOCs except octane, which followed zero-order kinetics. For some compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches. Abiotic disappearance is explained by slow intraparti- cle diffusion and sorption. It is concluded that the column approach is preferable for determining biodegradation rate parameters to be used in risk assessment models.

  7. Strength and Stiffness of Stabilized Alluvial Silt under Frost Actions

    Directory of Open Access Journals (Sweden)

    Haibo Wang


    Full Text Available The Yellow River alluvial silt was stabilized into pavement base materials for cold regions. The stabilizing additives were cement, fly ash, and lime, which were included in a range of combinations and dosages when mixed with the silt. Freeze-thaw cyclic impacts were conducted on the treated samples to assess materials performance of withstanding the frost actions. The tests were conducted on samples cured for 7 days to up to 180 days. Test results show that the cement-fly ash-treated samples outperform the other two stabilization categories with respect to material strength and stiffness developed under both normal and frost conditions. Under the normal conditions, the material unconfined compressive (UC strength rises to 3.0 MPa on day 28 depending on the cement and fly ash dosage used. If subjected to frost actions, the fly ash inclusions warrant a residual UC strength value of 1.3 MPa and above. The antifrost performance of the cement-fly ash-treated samples is related to thermal buffer capacity of the fly ash particles. Water adsorption and material soundness results agree with the strength and stiffness development. An optimal dosage was 3–6% for the cement and 0.3 for cement to fly ash mass ratio.

  8. Diagenesis of Permian alluvial fan deposits of Northern Switzerland

    International Nuclear Information System (INIS)

    Bluem, W.


    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

  9. Colonizing Dynamic Alluvial and Coastal Landscapes in the Holocene (United States)

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


    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.

  10. 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.

  11. Plain Polynomial Arithmetic on GPU

    International Nuclear Information System (INIS)

    Haque, Sardar Anisul; Maza, Marc Moreno


    As for serial code on CPUs, parallel code on GPUs for dense polynomial arithmetic relies on a combination of asymptotically fast and plain algorithms. Those are employed for data of large and small size, respectively. Parallelizing both types of algorithms is required in order to achieve peak performances. In this paper, we show that the plain dense polynomial multiplication can be efficiently parallelized on GPUs. Remarkably, it outperforms (highly optimized) FFT-based multiplication up to degree 2 12 while on CPU the same threshold is usually at 2 6 . We also report on a GPU implementation of the Euclidean Algorithm which is both work-efficient and runs in linear time for input polynomials up to degree 2 18 thus showing the performance of the GCD algorithm based on systolic arrays.

  12. Hydrocarbon Status of Alluvial Soils in the Istra Morphostructural Node (Moscow Oblast) (United States)

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


    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.

  13. Southern Great Plains Safety Orientation

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, John


    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.

  14. 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


    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

  15. Controls on the δ 34S and δ 18O of dissolved sulfate in the Quaternary aquifers of the North China Plain (United States)

    Li, Xiaoqian; Zhou, Aiguo; Gan, Yiqun; Yu, Tingting; Wang, Dong; Liu, Yunde


    SummaryThe North China Plain (NCP) is a typical Cenozoic sedimentary basin and one of the largest alluvial plains in eastern Asia. It consists of piedmont alluvial plain, central alluvial-lacustrine plain, and littoral alluvial plain from west to east, where Quaternary aquifer systems developed in different depths. Groundwater from these aquifers is the most important water resource and supports a population of 200 million in the NCP. Currently the Quaternary groundwater is depleting fast due to both human and natural factors. Characterizing biogeochemical processes in groundwater is central to understanding groundwater chemistry. To identify the sources of dissolved sulfate ( SO42-) and address subsequent biogeochemical processes in groundwater, we conducted a study of spatial distributions of δ 34S SO4 and δ 18O SO4 in the Quaternary aquifers in the northern part of the NCP. The [ SO42-], δ 34S SO4, and δ 18O SO4 along the west-east groundwater flowpaths in the three alluvial plains are analyzed and examined. The Quaternary groundwater (˜20 °C) has a [ SO42-] of 37.25-177.41 mg/L with [ SO42-]/[Cl -] ratios ranging from 0.12 to 2.79. The δ 34S SO4 and δ 18O SO4 range from 4.9‰ to 30.9‰ and from 4.7‰ to 14.0‰, respectively. Supported by other geochemical and isotopic parameters such as total dissolved solids (TDS) concentrations, δD and δ 18O of groundwater (δD and δ 18O H2O), and 14C contents in groundwater, our study concludes that: (1) The shallow groundwater in the piedmont area is characterized by higher SO42- concentration of 153.22 mg/L with δ 34S SO4 of 10.0-14.5‰ and δ 18O SO4 of 4.7-9.0‰, whereas the groundwater in the piedmont area is characterized by lower SO42- concentration of 37.25 mg/L with δ 34S SO4 of 4.9-7.3‰ and δ 18O SO4 of 5.8-7.5‰. Therefore, the SO42- in the shallow groundwater is dominated by weathered sulfate minerals from the Taihang mountains and sulfate derived from oxidation of sulfides in infiltration

  16. Cambrian to Devonian evolution of alluvial systems: The sedimentological impact of the earliest land plants (United States)

    Davies, Neil S.; Gibling, Martin R.


    In present-day alluvial environments, the impact of vegetation on sedimentological processes and deposits is well known. A vegetated catchment may decrease sediment yield, sediment erodibility, Hortonian overland flow, aeolian winnowing of fines, the proportion of sediment transported as bedload, and may increase bank stability, infiltration into substrates, and bed roughness. Vegetation also promotes the production of chemically-weathered clays and soils and the adoption of a meandering style. It is generally understood that, prior to the evolution of terrestrial vegetation during the Early Palaeozoic, ancient alluvial systems were markedly different from modern systems, with many systems adopting a "sheet-braided" style. This understanding has previously informed the interpretations of many Precambrian pre-vegetation alluvial successions, but there has been relatively little work regarding Early Palaeozoic alluvial successions laid down prior to and during the initial colonization of the Earth's surface by plants. A comprehensive review of 144 Cambrian to Devonian alluvial successions documented in published literature was combined with original field data from 34 alluvial successions across Europe and North America. The study was designed to identify changes in alluvial style during the period that vegetation was evolving and first colonizing alluvial environments. An increase in mudrock proportion and sandstone maturity is apparent, along with a decrease in overall sand grain size through the Early Palaeozoic. These trends suggest that primitive vegetation cover promoted the production and preservation of muds from the mid Ordovician onwards and increased the residence time of sand-grade sediment in alluvial systems. The compilation also enables the first stratigraphic occurrence of certain vegetation-dependent sedimentary features to be pinpointed and related to the evolution of specific palaeobotanical adaptations. The first markedly heterolithic alluvial

  17. Lower Palaeozoic Alluvial Systems: The Sedimentological Impact of Evolving Vegetation in Terrestrial Environments (United States)

    Davies, N. S.; Gibling, M. R.


    In present-day alluvial environments, the impact of vegetation on sedimentological processes and deposits is well known. A vegetated catchment may decrease sediment yield, sediment erodability, Hortonian overland flow, aeolian winnowing of fines, the proportion of sediment transported as bedload, may increase bank stability, infiltration into substrates, bed roughness, and can promote the production of chemically-weathered clays and soils and the adoption of a meandering style. It is generally understood that, prior to the evolution of terrestrial vegetation during the Lower Palaeozoic, ancient alluvial systems were markedly different from modern systems, with many systems adopting a "sheet-braided" style. This understanding has previously informed the interpretations of many Precambrian pre-vegetation alluvial successions, but there has been relatively little work regarding Lower Palaeozoic alluvial successions that existed during the active terrestrialization of plants. In this study, a comprehensive review of 141 Cambrian to Devonian alluvial successions documented in published literature was combined with original field data from 20 alluvial successions from across Europe and North America, in order to identify changes in the sedimentary style of alluvial strata while vegetation was evolving and colonizing alluvial environments. This approach has established clear trends indicating an increase in mudrocks and sandstone maturity and a decrease in overall sand grain size through the Lower Palaeozoic, suggesting that primitive vegetation cover was able to promote the production and preservation of muds and increase the residence time of sand-grade sediment (and thus sediment reworking) in alluvial systems. It has also enabled the first stratigraphic occurrence of certain vegetation-dependent sedimentary features to be pinpointed and tied directly to the onset of specific evolutionary adaptations recorded in the palaeobotanical fossil record. As such, the first

  18. 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.


    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

  19. Comparison of optimal irrigation scheduling and groundwater recharge at representative sites in the North China Plain (United States)

    Ma, Ying


    The North China Plain (NCP) is an important food production area in China, facing an increasing water shortage and overexploitation of groundwater. It is critical to optimize the irrigation scheduling and accurately estimate groundwater recharge for saving water and increasing crop water use efficiency. However, the water cycle and crop responses to irrigation are quite various in different areas, because of the spatial variation of climatic, soil, water table and other management practices in the NCP. In this study, three representative sites (LC site in the piedmont plain, TZ site in the northern alluvial and lacustrine plain, YC site in the southern alluvial and lacustrine plain) were selected to compare the optimal irrigation scheduling and corresponding groundwater recharge under different hydrological years for winter wheat-summer maize double cropping system. At each site, a physically based agro-hydrological model (SWAP) was calibrated using field data of soil moisture. Then, scenarios under different irrigation time and amount were simulated. Results showed that the optimal irrigation scheduling and corresponding groundwater recharge were significant different between the three representative sites. The mean water table depth at the LC (33.0 m), YC (10.3 m), and TZ site (2.5 m) caused great different time lags of infiltrated water and groundwater contribution to evapotranspiration. Then, the most irrigation amount was required for the TZ site but the least requirement for the YC site at each hydrologic year. As most clay contents in the deep soils at the LC site increased tortuosity and limited water movement, which resulted in lower rates of recharge compared to more sandy soils at the other two sites. Averagely, using the optimal irrigation scheduling could save 2.04×109 m3 irrigation water and reduce about 84.3% groundwater over-exploitation in winter wheat growth period in the NCP. Therefore, comparison of the simulation results among the three

  20. The influence of bed roughness on partial alluviation in an experimental bedrock channel (United States)

    Davis, J. R.; Sklar, L. S.; Demeter, G. I.; Johnson, J. P.; Whipple, K. X.


    The extent of alluvial cover on a bedrock channel bed strongly influences the efficiency of river incision, and can affect the quality of habitat for aquatic ecosystems. The extent of partial cover is commonly modeled as a simple function of sediment supply relative to the transport capacity of the stream, although other factors are likely to be important, particularly the roughness of the underlying bedrock surface. Here we report results of a set of laboratory experiments investigating the influence of bedrock channel bed topography on the dynamics of partial bed alluviation. The experiments were conducted in a tilting flume 8 m long and 0.3 m wide with an erodible bedrock bed made of a sand-cement mixture. The flume has a calibrated sediment feed and a double-basket sediment trap that provides a continuous record of sediment flux out of the downstream end. We used a uniform grain size of 5 mm, and varied the sediment supply rate from zero to that sufficient to create a fully alluviated bed. We created a variety of bedrock roughness conditions, from smooth, nearly planar surfaces to an egg-carton texture made with a plaster-coated foam mold. Intermediate roughness was achieved by chiseling into smooth beds and by allowing the bed topography to evolve by sustained bedload abrasion. We used a laser microtopography scanning device to make topographic maps of the bed surface, with a vertical resolution of 0.2 mm and a horizontal spacing of 5 mm. From these data we quantify bedrock bed roughness as the standard deviation of the distribution of bed elevations relative to a plane inclined at the mean bed slope. To guide our selection of bed roughness values we made topographic surveys of a number of bedrock channel beds, including partially alluviated channels where we dug trenches through alluvial deposits to expose the underlying bedrock surface. For each bed roughness condition we systematically varied the sediment supply rate and repeatedly mapped the extent of

  1. Dynamic analysis of a reactor building on alluvial soil

    International Nuclear Information System (INIS)

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


    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

  2. Evaluation of reforestation in the Lower Mississippi River Alluvial Valley (United States)

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


    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.

  3. Relating bulk electrical conduction to litho-textural properties and pore-fluid conductivity within porous alluvial aquifers (United States)

    Mele, M.; Giudici, M.; Inzoli, S.; Cavalli, E.; Bersezio, R.


    The estimate of hydraulic conductivity from Direct Current methods represents a powerful tool in aquifer characterization as both electrical and hydraulic conductivities depend on connected pore volumes and connected pore surface areas. A crucial, intermediate stage of this process is the assessment of sediments' textures and lithology from DC electrical conductivity as the electrical response of the aquifers' basic building blocks (i.e., hydrofacies) is controlled by the prevailing process of electrical conduction, electrolytic (σEL; pore-volume dominated) vs. "shale" (σSH; pore-surface dominated), determined by pore-space structure, clay distribution and electrical properties of pore fluids (σW). In this work laboratory experiments were conducted and the results were interpreted through the analysis i) of a volume-averaged, macroscopic litho-textural property of alluvial hydrofacies', the coarse-to-fine ratio (C/F), as a "proxy" of the process of electrical conduction within each samples on the basis of the volume proportion between nonconductive, coarse-grained and conductive, shaly textures and ii) of the surface conduction component, produced in fresh-to-salt water environment by clay materials. 8 hydrofacies' samples were collected with an hand-auger within the outcropping alluvial aquifers of the Quaternary meander river belt of the southernmost Lodi plain (northern Italy), represented by loose gravelly-sands to sands (6 samples), fine and sandy-silty clays (2 samples). As a first step, laboratory measurements of the bulk electrical conductivity (σB) of representative sub-samples, totally saturated with water with different salinity (σW from 125 to 1100 μs/cm), were performed. The experimental apparatus was made up by a series of polycarbonate, cylindrical cells (9cm x 12cm) equipped with external, copper plates as current electrodes and internal, copper squared-grids as potential electrodes. Electrical conductivity of each sample was obtained

  4. Depositional facies and Hohokam settlement patterns of Holocene alluvial fans, N. Tucson Basin, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Field, J.J.


    The distribution of depositional facies on eight Holocene alluvial fans of varying dimensions is used to evaluate prehistoric Hohokam agricultural settlement patterns. Two facies are recognized: channel gravelly sand facies and overbank silty sand facies. No debris flow deposits occur. The channel facies is characterized by relatively well sorted stratified sands and gravels with common heavy mineral laminations. Overbank facies deposits are massive and very poorly sorted due to heavy bioturbation. Lithostratigraphic profiles from backhoe trenches and sediment size analysis document headward migration of depositional facies which results in fining upward sequences. Each sequence is a channel fan lobe with an underlying coarse grained channel sand which fines to overbank silty sands. Lateral and vertical variations in facies distributions show that depositional processes are affected by drainage basin area (fan size) and distance from fan head. Gravelly channel sands dominate at the headward portions of the fan and are more pervasive on large fans; overbank silty sands are ubiquitous at fan toes and approach closer to the fan head of smaller alluvial fans. When depositional facies are considered as records of water flow over an alluvial surface, the farming potential of each fan can be analyzed. Depositional models of alluvial fan sedimentation provide the basis for understanding Hohokam settlement patterns on active alluvial surfaces.

  5. Alluvial systems as archives for environmental change at a Hominid site with Oldowan archaeological occurrences: the Homa Peninsula, southwestern Kenya (United States)

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


    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.

  6. Rome in its setting. Post-glacial aggradation history of the Tiber River alluvial deposits and tectonic origin of the Tiber Island. (United States)

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


    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.

  7. Water levels and water quality in the Mississippi River Valley alluvial aquifer in eastern Arkansas, 2012 (United States)

    Schrader, Tony P.


    During the spring of 2012, the U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, measured water levels in 342 wells completed in the Mississippi River Valley alluvial aquifer in eastern Arkansas. The Arkansas Natural Resources Commission measured water levels in 11 wells, and the U.S. Department of Agriculture-Natural Resources Conservation Service measured water levels in 239 wells completed in the alluvial aquifer and provided these data to the Arkansas Natural Resources Commission. In 2010, estimated water withdrawals from the alluvial aquifer in Arkansas totaled about 7,592 million gallons per day. Withdrawals more than doubled between 1985 and 2010, about a 115-percent increase.

  8. 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) (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

  9. Enhancing flood hazard estimation methods on alluvial fans using an integrated hydraulic, geological and geomorphological approach (United States)

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


    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.

  10. Geomorphological and cryostratigraphical analyses of the Zackenberg Valley, NE Greenland and significance of Holocene alluvial fans (United States)

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


    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.

  11. Database of Alluvial Radiocarbon Dates in European Russia and Siberia and its Palaeohydrological Interpretation (United States)

    Matlakhova, Ekaterina; Panin, Andrei


    We collected and analyzed published radiocarbon dates from East European Plain (EEP) and Siberia to pick absolute dates on alluvial and associated deposits. After filtering unreliable dates, 1000 radiocarbon dates from EEP and 500 from Siberia were included into the database. Each date was supplied with information on geographic location and coordinates, catchment area, geomorphological position, characteristics of geological section and dated materials. Also the information about published sources was given. Documented sections refer to fluvial forms in a wide range of catchment sizes. To extract palaeohydrological signal we used two kinds of proxies: sedimentological and geomorphological. We used the following indicators of low activity: organic horizons (soil, peat) in overbank alluvium, balka bottoms and gully fans, small river palaeochannels; and the following indicators of high activity: active sedimentation on river floodplains (burial of organic horizons), balka bottoms and gully fans, erosion by flood flows on floodplains, in bottoms of balkas and gullies, river incision, big palaeochannels, channel avulsions and chute cutoffs. 
 Each date that received palaeohydrological interpretation was regarded as the indicator of a particular Local Palaeohydrological Event. Combined probability density functions of high- and low-activity dates were used to detect time intervals of different palaeohydrological status. For EEP after low fluvial activity during LGM two palaeohydrological epochs were designated: extremely high activity in the end of MIS 2 (ca. 18-11.7 ka b2k), and much lower activity in the Holocene. Within the Holocene two hierarchical levels of hydroclimatic variability were designated according to their duration and magnitude - regional palaeohydrological phases (centuries to few millennia) and regional palaeofluvial episodes (decades to few centuries). Tendency is rather clear of activity lowering in the first half and rise in the second half of

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

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


    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

  13. A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity (United States)

    Phelps, G.A.; Halford, K.J.


    In Yucca Flat, on the Nevada National Security Site in southern Nevada, the migration of radionuclides from tests located in the alluvial deposits into the Paleozoic carbonate aquifer involves passage through a thick, heterogeneous section of late Tertiary and Quaternary alluvial sediments. An understanding of the lateral and vertical changes in the material properties of the alluvial sediments will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating groundwater flow in the Yucca Flat area. Previously published geologic models for the alluvial sediments within Yucca Flat are based on extensive examination and categorization of drill-hole data, combined with a simple, data-driven interpolation scheme. The U.S. Geological Survey, in collaboration with Stanford University, is researching improvements to the modeling of the alluvial section, incorporating prior knowledge of geologic structure into the interpolation method and estimating the uncertainty of the modeled hydrogeologic units.

  14. Hydrogeochemical processes and geochemical modeling in a coastal aquifer: Case study of the Marathon coastal plain, Greece (United States)

    Papazotos, Panagiotis; Koumantakis, Ioannis; Kallioras, Andreas; Vasileiou, Eleni; Perraki, Maria


    Determining the hydrogeochemical processes has always been a challenge for scientists. The aim of this work is the study of the principal hydrogeochemical processes controlling groundwater quality in the Marathon coastal plain, Greece, with emphasis on the origin of the solutes. Various physicochemical parameters and major ions of twenty-five groundwater samples were analyzed. The hydrogeochemical data of groundwater were studied in order to determine the major factors controlling the chemical composition and hydrogeochemical evolution. In the Marathon coastal plain, three different zones of the alluvial granular aquifer system have been detected, considering the geochemical processes and recharge, which affect its hydrochemical characteristics. The alluvial granular aquifer system is divided eastwards into three zones: a) the natural recharge zone, b) the reverse ion exchange zone and c) the diffusion sea water zone. Cl-is the dominant anion and Na+and Ca2+ are the dominant cations, as determined by plotting the analyses on the respective Piper diagram. Near the coastline high concentrations of Na+ and Cl- were observed indicating a zone of seawater intrusion. On the other hand, westward there is increasing concentration of HCO3- with simultaneous decrease of Na+is indication of a recharge zone from karstic aquifers of the study area. Between the aforementioned zones there is an intermediate one, where reverse ion exchange takes place due to high concentrations of dissolved Na+ and Ca2+ adsorption. The saturation indices (SI) were calculated using the geochemical modeling software PHREEQC. Mineral phases of halite, sylvite, gypsum and anhydrite were estimated to be undersaturated in the water samples, suggesting these phases are minor or absent in the host rock. On the other hand, calcite, aragonite and dolomite are close to equilibrium; these minerals are present in the host rocks or in the unsaturated zone, possibly increasing the Ca2+, Mg2+ and HCO3

  15. Climate variability and Great Plains agriculture

    International Nuclear Information System (INIS)

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


    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

  16. Integrating channel form and processes in the Gangetic plains rivers: Implications for geomorphic diversity (United States)

    Roy, N. G.; Sinha, R.


    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.

  17. Historical trajectories and restoration strategies for the Mississippi River alluvial valley (United States)

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


    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...

  18. Dam impacts on and restoration of an alluvial river-Rio Grande, New Mexico (United States)

    Gigi Richard; Pierre Julien


    The impact of construction of dams and reservoirs on alluvial rivers extends both upstream and downstream of the dam. Downstream of dams, both the water and sediment supplies can be altered leading to adjustments in the river channel geometry and ensuing changes in riparian and aquatic habitats. The wealth of pre and post-regulation data on the Middle Rio Grande, New...

  19. 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.


    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


    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...

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

    Directory of Open Access Journals (Sweden)

    Majkić-Dursun Brankica


    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

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

    Directory of Open Access Journals (Sweden)

    P. Négrel


    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

  3. From Okra to Oak: Reforestation of Abandoned Agricultural Fields in the Lower Mississippi Alluvial Valley (United States)

    Callie Jo Schweitzer; John A. Stanturf


    There has been a tremendous upsurge in interest in reforestation of bottomland hardwoods. In the lower Mississippi alluvial valley, reforestation projects are occurringon a large scale on abandoned agricultural fields, often in conjunction with state or federal cost-share programs. This paper describes some of the cost share programs used to establish bottomland...

  4. Spatial patterns of lacustrine fish assemblages in a catchment of the Mississippi Alluvial Valley (United States)

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


    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.

  5. Litterfall in the hardwood forest of a minor alluvial-floodplain (United States)

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


    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...

  6. Analysis of equivalent widths of alluvial channels and application for instream habitat in the Rio Grande (United States)

    Claudia A. Leon


    Rivers are natural systems that adjust to variable water and sediment discharges. Channels with spatial variability in width that are managed to maintain constant widths over a period of time are able to transport the same water and sediment discharges by adjusting the bed slope. Methods developed to de ne equilibrium hydraulic geometry characteristics of alluvial...

  7. 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


    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

  8. Afforestation of marginal agricultural land in the lower Mississippi River Alluvial Valley, U.S.A. (United States)

    John A. Stanturf; Callie J. Schweitzer; Emile S. Gardiner


    Afforestation of marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV) relies on native species, planted mostly in single-species plantations. Hard mast species such as oak and pecan are favored for their value to wildlife, especially on public land. Successful afforestation requires an understanding of site variation within floodplains and...


    Directory of Open Access Journals (Sweden)

    Z. V. Kalashnik


    Full Text Available The presented article considers the questions physico-mechanical characteristic soil recent alluvial sediments Volga-Akhtuba floodland in connection with designing and construction different industrial object, and first of all,oil-and-gas of the infrastructure.

  10. Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels

    NARCIS (Netherlands)

    Crosato, A.; Mosselman, E.; Desta, F.B.; Uijttewaal, W.S.J.


    Alternate bars in straight alluvial channels are migrating or nonmigrating. The currently accepted view is that they are nonmigrating if the width-to-depth ratio is at the value of resonance or if the bars are forced by a persistent local perturbation. We carried out 2-D numerical computations and a

  11. 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.


    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

  12. Carbon sequestration resulting from bottomland hardwood afforestation in the Lower Mississippi Alluvial Valley (United States)

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


    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...

  13. Timing and nature of alluvial fan and strath terrace formation in the Eastern Precordillera of Argentina (United States)

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


    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.

  14. Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico (United States)

    Antinao, José Luis; McDonald, Eric; Rhodes, Edward J.; Brown, Nathan; Barrera, Wendy; Gosse, John C.; Zimmermann, Susan


    A late Pleistocene to Holocene alluvial stratigraphy has been established for the basins of La Paz and San José del Cabo, in the southern tip of the Baja California peninsula, Mexico. Six discrete alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development. These criteria were supported using radiocarbon, optically stimulated luminescence and cosmogenic depth-profile geochronology. Major aggradation started shortly after ∼70 ka (Qt2), and buildup of the main depositional units ended at ∼10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units consist of multiple 1-3 m thick alluvial packages deposited as upper-flow stage beds that represent individual storms. Main aggradational units (Qt2-Qt4) occurred across broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are confined to channels of ∼0.5-2 km width. Continuous deposition inside the thicker (>10 m) pre-Qt5 units is demonstrated by closely spaced dates in vertical profiles. In a few places, disconformities between these major units are nevertheless evident and indicated by partly eroded buried soils. The described units feature sedimentological traits similar to historical deposits formed by large tropical cyclone events, but also include characteristics of upper-regime flow sedimentation not shown by historical sediments, like long (>10 m) wavelength antidunes and transverse ribs. We interpret the whole sequence as indicating discrete periods during the late Pleistocene and Holocene when climatic conditions allowed larger and more frequent tropical cyclone events than those observed historically. These discrete periods are associated with times when insolation at the tropics was

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

    Directory of Open Access Journals (Sweden)

    Doriano Castaldini


    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

  16. Southern Great Plains Atmospheric Radiation Measurement Site (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...

  17. Targeting the Plains of Venus from Orbit (United States)

    Sharpton, V. L.


    Lowland plains house a spectacular array of poorly understood volcanic, tectonic, and impact features that are key to settling the continuing global stratigraphy debate and resolving how the only other accessible Earth-sized planet has evolved.

  18. Plain Language: Getting Started or Brushing Up (United States)

    ... Institutes at NIH » NIH Office of the Director » Office of Communications & Public Liaison » Clear Communication » Plain ... This website consists of five sections and a checklist you can print. In each section, you will ...

  19. 44 CFR 10.14 - Flood plains and wetlands. (United States)


    ... 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...

  20. 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 ...

  1. Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting (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. Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels (United States)

    Wellman, Tristan


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tullis, J.A.


    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.

  4. Dating of river terraces along Lefthand Creek, western High Plains, Colorado, reveals punctuated incision (United States)

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


    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.

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

    International Nuclear Information System (INIS)

    Tullis, J.A.


    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

  6. Hiding video in plain sight (United States)

    Rosiene, Carolyn P.; Rosiene, Joel A.


    With the increasing number of digital transmissions, there is an opportunity to utilize existing broadcast channels to send hidden video transmissions. This presentation outlines and demonstrates a technique to insert a hidden video channel within a larger standard video feed, or 'hide in plain sight.' The approach outlined consists of three parts: data (or video) insertion, data security, and data recovery. These three components are essential to complete a secured digital transmission. To insert the data, knowledge of the standard (for example, MPEG 1, 2, or 4) is used to place the information to be hidden into the compressed data stream post quantization. Since the encoder has perfect knowledge of the receiver's model, it is possible to place the data in the compressed data in a manner that is visually un-intrusive. The technique to hide the data will be presented and an example given. Since, the data (or video) to be inserted may be of a sensitive nature, it is necessary to provide a level of security, which will render the video stream useless if its presence is detected. Both, spatial and temporal dispersion are used to reduce the likelihood of detection with the addition of a modulation of the signal to reduce the image to noise unless the key is known. The intended viewer of the embedded data (or video stream), with knowledge of the key recovers the data by encoding the incoming video stream with the appropriate standard, and extracting the data prior to quantization. While the work in this paper focuses on the insertion of hidden video into a broadcast signal, the same technique serves to prevent tampering to the broadcast signal, since modification of the image data will corrupt the hidden signal. In this way, this provides a level of tamper protection/detection for video, which may be used in legal proceedings.

  7. The role of discharge variability in the formation and preservation of alluvial sediment bodies (United States)

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


    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

  8. Application of flood index in monitoring Flood-plain ecosystems (by the example of the Middle Ob flood-plain)


    Bolotnov, V. P.


    The concept of regional hydroecological monitoring has been developed for the flood-plain of the Middle Ob. Its object is to control the state of flood-plain ecosystem productivity for organization of scientific, regional-adopted and ecologically regulated nature management. For this purpose hydroecological zoning of flood-plain territory performed, the most representative stations of water-gauge observations for each flood-plain zone organized, the scheme of flood-plain flooding was prepared...

  9. Paleoenvironmental interpretation of an ancient Arctic coastal plain: Integrated paleopedology and palynology from the Late Cretaceous (Maastrichtian) Prince Creek Formation, North Slope, Alaska, USA (United States)

    McCarthy, P. J.; Flaig, P. P.; Fiorillo, A. R.


    The Cretaceous (Early Maastrichtian), dinosaur-bearing Prince Creek Formation, North Slope, Alaska, records high-latitude, alluvial sedimentation and soil formation on a low-lying, coastal plain during a greenhouse phase in Earth history. This study combines outcrop observations, micromorphology, geochemistry, and palynological analyses of paleosols in order to reconstruct local paleoenvironments of weakly developed, high-latitude coastal plain soils. Sediments of the Prince Creek Fm. include quartz- and chert-rich sandstone channels, and floodplains containing organic-rich siltstone and mudstone, carbonaceous shale, coal and ashfall deposits. Vertically stacked horizons of blocky-to-platy, drab-colored mudstone and siltstone with carbonaceous root-traces and mottled aggregates alternating with sandy units indicate that the development of compound and cumulative, weakly-developed soils on floodplains alternated with overbank alluviation and deposition on crevasse splay complexes on floodplains . Soil formation occurred on levees, point bars, crevasse splays and along the margins of floodplain lakes, ponds, and swamps. Soil-forming processes were interrupted by repeated deposition of sediment on top of soil profiles by flooding of nearby channels. Alluviation is evidenced by thin (coatings, and zoned peds suggest periodic waterlogging, anoxia and gleying. In contrast, Fe-oxide mottles, ferruginous and manganiferous segregations, burrows, and rare illuvial clay coatings suggest recurring oxidation and periodic drying out of some soils. Jarosite mottles and halos, and rare pyrite and gypsum found in some distal paleosols implies a marine influence at the distal margins of the coastal plain. Biota including Peridinioid dinocysts, brackish and freshwater algae, fungal hyphae, fern and moss spores, projectates, age-diagnostic Wodehouseia edmontonicola, hinterland bisaccate pollen and pollen from lowland trees, shrubs, and herbs indicate an Early Maastrichtian age for

  10. The intricacies of “being able to work undisturbed” - The organization of alluvial gold mining in Bolivia

    NARCIS (Netherlands)

    Salman, A.J.


    This article on small-scale alluvial gold mining in Bolivia shows how cultural practices, social patterns, and institutions, policies and politics are connected to technologies, physical environments, infrastructure, and landscapes. It presents a detailed description of the techniques, material

  11. Late Pleistocene dip-slip faulting along the Dunajec Fault, West Carpathians: Insights from alluvial sediments (United States)

    Olszak, Janusz


    This paper presents vertical movement along the Dunajec Fault during the Late Pleistocene and suggests Quaternary tectonic reactivation of diagonal strike-slip faults and their transformation into dip-slip faults in the West Carpathians. Optically stimulated luminescence (OSL) dating of Pleistocene alluvial sediments of the Dunajec and the Ochotnica rivers was employed to determine the time range of deposition of these sediments. Vertical and spatial distribution of the obtained OSL ages imply that the alluvial sediments were affected by the Dunajec Fault, which appears to have acted as a scissor fault during the Late Pleistocene. The results contribute to the discussion on the recent evolution of the Carpathians, and may support the concept of extensional collapse of the orogen.

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

    Directory of Open Access Journals (Sweden)

    Hassan Ibrahim Mohamed


    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.

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

    International Nuclear Information System (INIS)

    Eberhards, G.; Saltupe, B.


    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)

  14. Comparative Study Of Alluvial Cnidion-Type Meadows In The Lower Danube River Basin

    Directory of Open Access Journals (Sweden)

    Schneider-Binder Erika


    Full Text Available Alluvial Cnidion-type meadows (Habitat type 6440 of the Habitats Directive, mostly characteristic for the lower courses of large rivers in continental climate conditions of Europe are presented from the Lower Danube upstream the municipality of Giurgiu (river-km 510-524. The ecological requirements of the characteristic species, as well as their sensitivity to human-induced changes that derive from regular flooding, drainage, intensification of use and/or abandonment, are highlighted; these changes frequently lead to a decrease of biodiversity of the Cnidion-type meadows or to their total loss The studied meadows are compared with similar alluvial meadows from other sites of the lower Danube River basin. Finally, the strong interlocking of Cnidion type meadows with those of the Agropyro-Rumicion, Molinion and Deschampsion caespitosae alliances are discussed.

  15. 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.


    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.

  16. Upstream effects of dams on alluvial channels: state-of-the-art and future challenges (United States)

    Liro, Maciej


    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

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


    Gerisch, Michael


    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...

  18. Bed load tracer mobility in a mixed bedrock/alluvial channel (United States)

    Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.


    The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate bed load transport during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial sediment cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.

  19. SH waves scattering from a partially filled semi-elliptic alluvial valley (United States)

    Tsaur, Deng-How; Hsu, Ming-Sheng


    The scattering of SH waves induced by a partially filled semi-elliptic alluvial valley is explored via the region-point-matching technique (RPMT). Appropriate radial and angular Mathieu functions are well utilized to express the antiplane displacement fields. With the aid of the coordinate-transformed relation, which is intended as a substitute for the addition theorem (involving multiple summations of Mathieu functions), the application of the RPMT facilitates the rapid construction of simultaneous equations. Enforcement of zero-stress conditions on the curved valley surface and continuity conditions on the soil-bedrock interface leads to the determination of unknown coefficients. Comparisons with published data for several limiting cases (e.g. those pertaining to the truncated semi-circular canyon, the partially filled semi-circular alluvial valley, the totally empty semi-elliptic canyon and the fully filled semi-elliptic alluvial valley) show good agreement. Effects of pertinent parameters on steady-state surface motions are demonstrated. Transient changes in surface displacement amplitude are also included.

  20. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian. (United States)

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


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

    Directory of Open Access Journals (Sweden)



    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.

  2. Natural hazards on alluvial fans: the debris flow and flash flood disaster of December 1999, Vargas state, Venezuela (United States)

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


    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

  3. Geochemistry of ground water in alluvial basins of Arizona and adjacent parts of Nevada, New Mexico, and California (United States)

    Robertson, Frederick N.


    Chemical and isotope analyses of ground water from 28 basins in the Basin and Range physiographic province of Arizona and parts of adjacent States were used to evaluate ground-water quality, determine processes that control ground-water chemistry, provide independent insight into the hydrologic flow system, and develop information transfer. The area is characterized by north- to northwest-trending mountains separated by alluvial basins that form a regional topography of alternating mountains and valleys. On the basis of ground-water divides or zones of minimal basin interconnection, the area was divided into 72 basins, each representing an individual aquifer system. These systems are joined in a dendritic pattern and collectively constitute the major water resource in the region. Geochemical models were developed to identify reactions and mass transfer responsible for the chemical evolution of the ground water. On the basis of mineralogy and chemistry of the two major rock associations of the area, a felsic model and a mafic model were developed to illustrate geologic, climatic, and physiographic effects on ground-water chemistry. Two distinct hydrochemical processes were identified: (1) reactions of meteoric water with minerals and gases in recharge areas and (2) reactions of ground water as it moves down the hydraulic gradient. Reactions occurring in recharge and downgradient areas can be described by a 13-component system. Major reactions are the dissolution and precipitation of calcite and dolomite, the weathering of feldspars and ferromagnesian minerals, the formation of montmorillonite, iron oxyhydroxides, and probably silica, and, in some basins, ion exchange. The geochemical modeling demonstrated that relatively few phases are required to derive the ground-water chemistry; 14 phases-12 mineral and 2 gas-consistently account for the chemical evolution in each basin. The final phases were selected through analysis of X-ray diffraction and fluorescence data

  4. Mountains and plains Denver's geologic setting (United States)



    A slice of geologic history is exposed to view in the Denver, Colorado area. Denver is situated on the High Plains near the east front of the Rocky Mountains. As one travels westward from Denver toward the mountains, successively older rocks are crossed from the geologically young rocks of the High Plains and the South Platte River valley to the older rocks of the foothills and the ancient rocks of the mountains. Thus, within a few miles,the journey turns back the pages of time in a lifesized textbook that vividly illustrates the geologic events that shaped the landscape.

  5. Plain packaging policy: Preventing industry innovations. (United States)

    Al-Hamdani, Mohammed


    The pack is a marketing tool for the tobacco industry - its shape, colour, fonts, descriptors and logos attract and mislead smokers. Health warnings on cigarette packs serve as a knowledge reminder for smokers to quit smoking. Plain packaging eliminates brand imagery elements from cigarette packs and has many benefits, including the reduction of intention to smoke and the denormalization of smoking behaviour. The tobacco industry has devised pack and product marketing innovations that thwart the effectiveness of health warnings. Plain packaging policy needs to address these innovations by restricting their use and preventing them from undermining health warnings.

  6. Age and origin of the Gezira alluvial fan between the Blue and White Nile rivers (United States)

    Williams, martin


    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

  7. Water resources of the Lower Rio Grande de Arecibo alluvial valley, Puerto Rico (United States)

    Quinones-Aponte, Vicente


    An assessment of the surface and groundwater resources of the lower Rio Grande de Arecibo alluvial valley was made between 1981 and 1983. Rio Grande de Arecibo is the major source of water in the valley with a mean-annual discharge of 527 cu ft/sec (382,000 acre-ft/yr). Its lowest mean-daily flow (low flow) during 12 yr of record is 50 cu ft/sec. Withdrawals of water from Rio Grande de Arecibo exceeding 15 cu ft/sec during periods of extreme low flows could cause reduction of recharge to the aquifer. However, withdrawals of as much as 35 cu ft/sec are possible when base flow ranges from 90 to 200 cu ft/sec without causing a reduction of aquifer recharge. An unconfined aquifer within the alluvial valley is hydraulically continuous with bordering limestone formations. A clay layer divides the alluvial aquifer into two separate hydraulic systems. Groundwater from the alluvial aquifer above the clay layer has not been widely developed. However, high yielding wells presently yield as much as 9.6 mil gal/day (10,800 acre-ft/yr) from the aquifers occurring below the clay layer within the alluvium and underlaying limestones. Transmissivity ranges from 3,000 sq ft/day in the alluvial area to 42,000 sq ft/day in the adjacent limestone areas. Total groundwater flow through aquifers within the study area (excluding water withdrawn by wells) is about 20.6 mil gal/day (23,100 acre-ft/yr). 50% of this amount is estimated to flow to the eastern area of Cano Tiburones and discharges as springs and seeps. An estimated 9.4 mil gal/day (10,500 acre-ft/yr) of additional groundwater can be withdrawn from the aquifers below the clay layer without reversing the northward hydraulic gradient. Seepage from Rio Grande de Arecibo to the groundwater system at the east side of the valley is probably the key to the development of groundwater resources in the Arecibo area. San Pedro spring, with an average discharge of 8.6 mil gal/day (9,600 acre-ft/yr), is undeveloped and represents a potential

  8. Controls on sediment cover in bedrock-alluvial channels of the Henry Mountains, Utah (United States)

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


    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

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

    Directory of Open Access Journals (Sweden)

    H. Qin


    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.

  10. Characterizing groundwater/surface-water interactions in the interior of Jianghan Plain, central China (United States)

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


    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.

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

    Paladino, Ombretta; Seyedsalehi, Mahdi; Massabò, Marco


    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.

  12. Hydrology, vegetation, and soils of four north Florida River flood plains with an evaluation of state and federal wetland determinations (United States)

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


    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

  13. 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


    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

  14. 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 ...

  15. Plain language as alternative textualisation | Cornelius | Southern ...

    African Journals Online (AJOL)

    Plain language is a form of intra-lingual translation, a process during which particular interventions are brought to bear on a complex text, such as an act, in order to fit the linguistic competence of a particular target audience (Bhatia, 1983; 1993). In this way, complicated content is unlocked and meaning mediated. The aim is ...

  16. Radiocesium in wheat of the Po plain

    International Nuclear Information System (INIS)

    Dominici, G.; Malvicini, A.


    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

  17. Porosity Prediction of Plain Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Muhammad Owais Raza Siddiqui


    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.

  18. Hydrogeochemical analysis for Tasuj plain aquifer, Iran

    Indian Academy of Sciences (India)

    Therefore, groundwater quality monitoring and protection are essential to sustain the Tasuj plain aquifer. For this purpose, a fundamental understanding of hydrogeochemi- cal processes and hydrogeological conditions for an aquifer system is important (Adams et al. 2001;. Keywords. Graphical method; hydrogeochemistry ...

  19. 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)


    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.

  20. Defining 'plain language' in contemporary South Africa

    African Journals Online (AJOL)

    Kate H

    a problem, as Kimble (1992: 14-15) argues in the following quote: […] It is no criticism that Plain .... Formulas do not consider the motivation, interests, purpose, and social and cultural background and context of .... way that gives a cooperative, motivated person a good chance of understanding the document at first reading, ...

  1. Unusual plain film appearance of extrapleural hematoma

    International Nuclear Information System (INIS)

    Ranner, G.; Kullnig, P.; Dirnhofer, R.; Sigrist, T.


    Two cases of extrapleural hematoma, proven during autopsy, are presented. Plain chest films did not demonstrate the typical signs of an extrapleural mass lesion. The roentgenologic differential diagnosis of a free or partially encapsulated pleural effusion, as well as the pathogenesis of extrapleural hematoma is discussed. (orig.) [de

  2. Great plains regional climate assessment technical report (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...


    African Journals Online (AJOL)

    As a result, this study carryout experimental, numerical and analytical investigation to study the behaviour of plain concrete (PC) beams strengthened with High Performance Fibre Reinforced Concrete (HPFRC) layer using three different jacketing configurations and tested in flexure. Results show significant improvement in ...

  4. 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.


    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.

  5. 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 (United States)


    Definition impermeable layers (e.g., hardpans), slow lateral drainage, and low hydraulic gradients. Mineral soil flats that accumulate peat can...variables and provides the data necessary for calibrating model variables and assessment models. Finally, they provide a concrete physical...relatively impermeable layers, causing lateral movement of groundwater. Typically, where groundwater flow is relatively constant (perennial seeps

  6. Writing Government Policies and Procedures in Plain Language (United States)

    Byrne, Don


    Plain language involves more than just a few simple techniques, such as using everyday words, short sentences, and active voice. Although there is no single definition, "plain language" basically stands for several dozen well-established principles of clear communication. In this article, the author discusses the significance of plain language…

  7. 49 CFR 215.111 - Defective plain bearing. (United States)


    ... 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...

  8. 49 CFR 230.102 - Tender plain bearing journal boxes. (United States)


    ... 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...

  9. 7 CFR 650.25 - Flood-plain management. (United States)


    ... delineates the base flood plain by using detailed HUD flood insurance maps and other available data, as... practicable alternatives to the proposed project that would not cause adverse effects on the base flood plain... beneficial values in base (100-year) flood plains as part of technical and financial assistance in the...

  10. 49 CFR 215.113 - Defective plain bearing wedge. (United States)


    ... 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...

  11. Plains Energy Services Ltd. 1998 annual report

    International Nuclear Information System (INIS)


    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

  12. 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)


    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.

  13. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon (United States)

    Lindholm, G.F.


    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

  14. Denudation rates from mass balance on alluvial fans in the chinese Tian Shan (United States)

    Guerit, Laure; Barrier, Laurie; Métivier, François; Jolivet, Marc; Fu, Bihong


    Denudation is a key process for mountain ranges evolution as it is an essential parameter to study the mass transfer over the Earth surface, the evolution of reliefs, or the complex relationships between climate, erosion and landscape changes. Several methods have been develop to quantify denudation such as the estimation of paleo-sediment fluxes from mass budget. In fact, markers of erosion within drainage areas are often scarce, temporary and difficult to reach. At the outlet of mountain belts, more continuous and perennial records of deposition can be found in sedimentary basins. Sediment budget is thus a powerful approach, generally used at the scale of sedimentary basins. However, this method can also be applied on smaller sedimentary systems, such as alluvial fans. Yet, it is seldom used on these systems, and consequently, its accuracy is barely questioned. We propose to implement such a method on several alluvial fan systems in the Chinese part of the Tian Shan Range, where estimations of denudation rates have already been proposed. Based on the reconstruction of two generations of alluvial fans, we estimate the volume of sediment exported out of the drainage system of the range for the Middle- Late Pleistocene (300 000 to ~11 000 y) and for the Holocene (~11 000 y to present). From these volumes, we derive denudation rates of ~135 m/My at maximum for these two periods, in good agreement with previous mass balance studies. Despite a strong change in the morphology of the piedmont at the onset of the Holocene, denudation rate seems quite stable within the hinterland mountains. This value is quite low for such a range. Based on a comparison of denudation rates observed in other areas over the world with comparable shortening or precipitation rates, we suggest that the low denudation rate observed in the chinese Tian Shan is related to the limited amount of precipitation.

  15. 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.


    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)

  16. Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers. (United States)

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


    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

  17. Regional water quality patterns in an alluvial aquifer: direct and indirect influences of rivers. (United States)

    Baillieux, A; Campisi, D; Jammet, N; Bucher, S; Hunkeler, D


    The influence of rivers on the groundwater quality in alluvial aquifers can be twofold: direct and indirect. Rivers can have a direct influence via recharge and an indirect one by controlling the distribution of fine-grained, organic-carbon rich flood deposits that induce reducing conditions. These direct and indirect influences were quantified for a large alluvial aquifer on the Swiss Plateau (50km(2)) in interaction with an Alpine river using nitrate as an example. The hydrochemistry and stable isotope composition of water were characterized using a network of 115 piezometers and pumping stations covering the entire aquifer. Aquifer properties, land use and recharge zones were evaluated as well. This information provided detailed insight into the factors that control the spatial variability of groundwater quality. Three main factors were identified: (1) diffuse agricultural pollution sources; (2) dilution processes resulting from river water infiltrations, revealed by the δ(18)OH2O and δ(2)HH2O contents of groundwater; and (3) denitrification processes, controlled by the spatial variability of flood deposits governed by fluvial depositional processes. It was possible to quantify the dependence of the nitrate concentration on these three factors at any sampling point of the aquifer using an end-member mixing model, where the average nitrate concentration in recharge from the agricultural area was evaluated at 52mg/L, and the nitrate concentration of infiltrating river at approximately 6mg/L. The study shows the importance of considering the indirect and direct impacts of rivers on alluvial aquifers and provides a methodological framework to evaluate aquifer scale water quality patterns. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Advancing Physically-Based Flow Simulations of Alluvial Systems Through Atmospheric Noble Gases and the Novel 37Ar Tracer Method (United States)

    Schilling, Oliver S.; Gerber, Christoph; Partington, Daniel J.; Purtschert, Roland; Brennwald, Matthias S.; Kipfer, Rolf; Hunkeler, Daniel; Brunner, Philip


    To provide a sound understanding of the sources, pathways, and residence times of groundwater water in alluvial river-aquifer systems, a combined multitracer and modeling experiment was carried out in an important alluvial drinking water wellfield in Switzerland. 222Rn, 3H/3He, atmospheric noble gases, and the novel 37Ar-method were used to quantify residence times and mixing ratios of water from different sources. With a half-life of 35.1 days, 37Ar allowed to successfully close a critical observational time gap between 222Rn and 3H/3He for residence times of weeks to months. Covering the entire range of residence times of groundwater in alluvial systems revealed that, to quantify the fractions of water from different sources in such systems, atmospheric noble gases and helium isotopes are tracers suited for end-member mixing analysis. A comparison between the tracer-based mixing ratios and mixing ratios simulated with a fully-integrated, physically-based flow model showed that models, which are only calibrated against hydraulic heads, cannot reliably reproduce mixing ratios or residence times of alluvial river-aquifer systems. However, the tracer-based mixing ratios allowed the identification of an appropriate flow model parametrization. Consequently, for alluvial systems, we recommend the combination of multitracer studies that cover all relevant residence times with fully-coupled, physically-based flow modeling to better characterize the complex interactions of river-aquifer systems.

  19. Geologic Characterization of Young Alluvial Basin-Fill Deposits from Drill Hole Data in Yucca Flat, Nye County, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Donald S. Sweetkind; Ronald M. Drake II


    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada, that has been the site of numerous underground nuclear tests; many of these tests occurred within the young alluvial basin-fill deposits. The migration of radionuclides to the Paleozoic carbonate aquifer involves passage through this thick, heterogeneous section of Tertiary and Quaternary rock. An understanding of the lateral and vertical changes in the material properties of young alluvial basin-fill deposits will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating ground-water flow in the Yucca Flat area. This report by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, presents data and interpretation regarding the three-dimensional variability of the shallow alluvial aquifers in areas of testing at Yucca Flat, data that are potentially useful in the understanding of the subsurface flow system. This report includes a summary and interpretation of alluvial basin-fill stratigraphy in the Yucca Flat area based on drill hole data from 285 selected drill holes. Spatial variations in lithology and grain size of the Neogene basin-fill sediments can be established when data from numerous drill holes are considered together. Lithologic variations are related to different depositional environments within the basin including alluvial fan, channel, basin axis, and playa deposits.

  20. 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.


    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

  1. The distribution and modeling of nitrate transport in the Carson Valley alluvial aquifer, Douglas County, Nevada (United States)

    Naranjo, Ramon C.; Welborn, Toby L.; Rosen, Michael R.


    Residents of Carson Valley in Douglas County, Nevada, rely on groundwater from an alluvial aquifer for domestic use and agricultural irrigation. Since the 1970s, there has been a rapid increase in population in several parts of the valley that rely on domestic wells for drinking water and septic systems for treatment of household waste. As a result, the density of septic systems in the developed areas is greater than one septic system per 3 acres, and the majority of the domestic wells are shallow (screened within 250 feet of the land surface).

  2. Genetics, medicine, and the Plain people. (United States)

    Strauss, Kevin A; Puffenberger, Erik G


    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.

  3. Does 'Plain Packaging' of Tobacco matter?

    Directory of Open Access Journals (Sweden)

    Luke Clancy


    Full Text Available The incremental tightening of the tobacco industry’s advertising capabilities led to the investment of billions of dollars into increasingly creative packaging. Today, packing remains one of the industry’s sole methods of promotion and marketing. The size, shape, colour, and font on cigarette packs serve to differentiate brands and promote a certain image associated with the given cigarette package Many studies in recent years have tested the association between pack standardisation and peoples’ attitudes, behaviours, and perceptions of tobacco packaging. The results show that plain packs are thought to be less attractive and associated with less positive characteristics, the health warnings are more salient, and smokers report feelings of wanting to smoke less when using standardised packs. Now we have the real life results from Australia, which show the tobacco control advances that are possible with standardised packaging. This must increase the pressure to have 'plain packaging' introduced throughout the EU.

  4. Management of Alluvial Forests Included in Natura 2000 91E0* Habitat Type in Maramureş Mountains Nature Park

    Directory of Open Access Journals (Sweden)

    Danci Oana


    Full Text Available The Natura 2000 habitat type 91E0* Alluvial forests of Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae include three subtypes of forests. In the Maramureș Mountains Nature Park (MMNP the alluvial forests are represented by Alnus incana forest situated on the banks of mountain rivers. Starting from 2007, 70% of the MMNP is also a Natura 2000 site of community interest. In the standard form for the site are listed 18 Natura 2000 habitat types, but that of alluvial forests 91E0* is not listed either due to an error or lack of available research data. Our study seeks to provide information regarding this high conservation value habitat such as: structure, distribution,managementmeasures andmonitoring protocol. The purpose of this paper is to offer a management tool for this conservation value habitat which is also exposed to human impact more than any other priority habitat in MMNP.

  5. Ages of plains volcanism on Mars (United States)

    Hauber, Ernst; Jagert, Felix; Broz, Petr


    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.

  6. Monsoon triggered formation of Quaternary alluvial megafans in the interior of Oman (United States)

    Blechschmidt, Ingo; Matter, Albert; Preusser, Frank; Rieke-Zapp, Dirk


    A vast bajada consisting of coalescing low-gradient (age termed Barzaman Formation, diagenetically highly altered to dolomitic clays, and a thin veneer of weakly cemented Quaternary gravels. A combination of remote sensing, lithological analyses and luminescence dating is used to interpret the complex aggradation history of the Quaternary alluvial fans from the interior of Oman in the context of independent regional climate records. From satellite imagery and clast analysis four fans can be discerned in the study area. While two early periods of fan formation are tentatively correlated to the Miocene-Pliocene and the Early Pleistocene, luminescence dating allows the distinction of five phases of fan aggradation during the Middle-Late Pleistocene. These phases are correlated with pluvial periods from Marine Isotope Stage (MIS) 11 through 3, when southern Arabia was affected by monsoonal precipitation. It is concluded that the aggradation of the alluvial fans was triggered by the interplay of increased sediment production during arid periods and high rainfall with enhanced erosion of hillslopes and transport rates during strong monsoon phases. However, the lack of fine-grained sediments, bioturbation and organic material implies that although the Quaternary fans are sourced by monsoonal rains they formed in a semi-arid environment. Thus, it appears that, in contrast to the Oman Mountains, the interior was not directly affected by monsoonal precipitation.

  7. Hydrogeochemistry of alluvial groundwaters in an agricultural area: an implication for groundwater contamination susceptibility. (United States)

    Chae, Gi-Tak; Kim, Kangjoo; Yun, Seong-Taek; Kim, Kyoung-Ho; Kim, Soon-Oh; Choi, Byoung-Young; Kim, Hyoung-Soo; Rhee, Chul Woo


    Alluvial groundwaters in the area where intensive agricultural activity takes place were geochemically investigated to evaluate factors regulating groundwater quality of alluvial aquifers. For this study, 55 groundwater samples were taken from the uniformly distributed irrigation wells and were classified into three distinct groups according to their geochemical characteristics. This study reveals that the groundwater quality and the geochemical characteristics of the clustered groups are consistent with the geology of the area. The samples collected from the area where a thick silt bed overlies the sand aquifer are clustered into Group II and show water quality that is only slightly affected by the contaminants originating from the land surface. However, groundwaters of this group are very high in Fe and Mn levels due to strong anoxic condition caused by the thick silt bed. In contrast, Group I shows water quality largely influenced by agricultural activities (i.e., fertilization, liming) and occurs in the area adjacent to the river where the silt bed is not observed and the sand aquifer is covered with sandy soils. Group III mostly occurs in the upgradient of Group I where a thin, silty soil covers the sand aquifer. In overall, the results show that the clustered groups closely reflect the groundwater susceptibility to the contaminants originated from the land surface. This suggests that groundwater clustering based on water chemistry could be applied to the contamination susceptibility assessment for groundwaters in the agricultural area.

  8. Regional patterns of extreme precipitation on Titan consistent with observed alluvial fan distribution (United States)

    Faulk, S. P.; Mitchell, J. L.; Moon, S.; Lora, J. M.


    Geomorphic features typically associated with extreme rainfall events in terrestrial settings, including extensive fluvial features and alluvial fans, have been detected on Titan's surface. Methane flow from precipitation on Titan can transport sediments and potentially erode the icy bedrock, but averaged precipitation rates from prior global-scale modelling are too low by at least an order of magnitude to initiate sediment transport of observed grain sizes at low latitudes. Here, we quantify the regional magnitude, frequency and variability of extreme rainfall events from simulations of present-day Titan, with a general circulation model coupled to a land model partially covered by wetlands reservoirs that can capture Titan's regionally varying hydroclimate. We find that the most extreme storms tend to occur in the mid-latitudes, where observed alluvial fans are most concentrated. Storms capable of sediment transport and erosion occur at all latitudes in our simulations, consistent with the observed global coverage of fluvial features. Our results demonstrate the influential role of extreme precipitation in shaping Titan's surface. We therefore suggest that, similarly to Earth but differently from Mars, active geomorphic work may be ongoing in the present climate on Titan.

  9. Effects of silicon on photosynthetic characteristics of maize (Zea mays L.) on alluvial soil. (United States)

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


    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.

  10. 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)


    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.

  11. 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))


    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.

  12. 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.


    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

  13. 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:; 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)


    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.

  14. The impact of medium architecture of alluvial settings on non-Fickian transport (United States)

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


    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.

  15. Monitoring biocalcification potential of Lysinibacillus sp. isolated from alluvial soils for improved compressive strength of concrete. (United States)

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


    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.

  16. Correlation and dating of Quaternary alluvial-fan surfaces using scarp diffusion (United States)

    Hsu, Leslie; Pelletier, Jon D.


    Great interest has recently been focused on dating and interpreting alluvial-fan surfaces. As a complement to the radiometric methods often used for surface-exposure dating, this paper illustrates a rapid method for correlating and dating fan surfaces using the cross-sectional shape of gullies incised into fan surfaces. The method applies a linear hillslope-diffusion model to invert for the diffusivity age, κt (m 2), using an elevation profile or gradient (slope) profile. Gullies near the distal end of fan surfaces are assumed to form quickly following fan entrenchment. Scarps adjacent to these gullies provide a measure of age. The method is illustrated on fan surfaces with ages of approximately 10 ka to 1.2 Ma in the arid southwestern United States. Two areas of focus are Death Valley, California, and the Ajo Mountains piedmont, Arizona. Gully-profile morphology is measured in two ways: by photometrically derived gradient (slope) profiles and by ground-surveyed elevation profiles. The κt values determined using ground-surveyed profiles are more consistent than those determined using photo-derived κt values. However, the mean κt values of both methods are comparable. The photometric method provides an efficient way to quantitatively and objectively correlate and relatively-date alluvial-fan surfaces. The κt values for each surface are determined to approximately 30-50% accuracy.

  17. Fourier grain shape analysis: a means for correlating alluvial deposits at the Nevada Test Site

    International Nuclear Information System (INIS)

    Grothaus, B.T.; Hage, G.L.


    Quartz sand derived from alluvial fans that drain different lithologies at the Nevada Test Site can be distinguished on the basis of grain shape as described by the Fourier series in closed form. Specifically, we examined tuff units from the Piapi Canyon and Indian Trail Formations as well as carbonate-bearing clastic units from the Eleana Formation. Discrimiation between rock types was accomplished by examining the mean harmonic amplitude spectra and the grain shape frequency distributions at those harmonics that exhibit significant chi-square values. The results of these analyses indicate that the tuffs can be easily distinguished from the clastics. However, differences between samples from genetically similar rock types are not as prominent. Grain shape frequency distributions of tuffs and clastics show such strong differences that they can be characterized by standardized distributions. By comparing the shape frequency distributions of mixed sediment samples, it is possible to determine the relative contribution of tuff and clastics to any sediment sample taken within the drainage network. The Piapi Canyon, Indian Trail, and Eleana Formations have produced the thick alluvium sequence in the Rainier Mesa region of Yucca Flat. We believe it is likely that these grain shape relationships can also be applied to subsurface samples. Not only would this extended application enable more accurate correlation of alluvial layers, but more precise determination of the clastic-tuff contact within the alluvium sequence might also be possible

  18. Geophysical study for saline water intrusion in a coastal alluvial terrain (United States)

    Choudhury, Kalpan; Saha, D. K.; Chakraborty, P.


    Geophysical investigations comprising electrical resistivity and shallow seismic refraction methods have been employed in the alluvial coastal belt of Digha, in the Eastern India for environmental study, to investigate the nature and status of subsurface saline water contamination. Geophysical surveys have delineated different subsurface geological formations such as dune sand, top sandy soil, saline sand and saline clay on the basis of their characteristic resistivity and velocity signatures. It is also inferred from geophysical interpretation that the thickness of the near-surface saline zone decreases inland away from the shore. Fortunately for Digha, clay layers present at different subsurface levels, which have probable extensions under the sea, have acted as barriers against any large-scale saline water intrusion at depth, even though pockets of saline/brackish zones have been interpreted in the subsurface. Clay formations are predominant up to a depth of about 60 m in the area below which an aquifer zone has been demarcated. A few locales that are already saline or are vulnerable for saline water intrusion have been identified at different depth levels and these zones should be avoided for ground water development. Further, several comparatively safe zones where ground water can be effectively exploited, have been delineated in the area. It has been observed that geophysical methods are highly useful in the environmental study for assessing saline water intrusion in alluvial terrain even in the presence of thick clay formations.

  19. A participatory approach of flood vulnerability assessment in the Banat Plain, Romania (United States)

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


    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

  20. Investigation on earthquake ground motions observed along a north-south survey line in the Kumamoto Plain, during the aftershocks of 2016 Kumamoto earthquake (United States)

    Tsuno, S.; Korenaga, M.; Okamoto, K.; Chimoto, K.; Yamanaka, H.; Yamada, N.; Matsushima, T.


    To evaluate local site effects in the Kumamoto Plain, we installed 15 temporary seismic stations along the north-south survey line, after the 2016 Kumamoto earthquake foreshock (Mj 6.4). In this report, to investigate earthquake ground motions observed along the north-south survey line, we estimated site amplification factors from weak ground motion data and estimated S-wave velocity structures by array microtremor observations at temporary seismic stations. We installed 15 temporary seismic stations at an interval of 300m to 2.5km along the north-south survey line. We estimated site amplification factors, with a station at Mt. Kinbo as a reference. Site amplification factors at the middle part and the southern part along the survey line, located in the alluvial lowland, were dominated in the frequency of 1-2Hz. On the other hand, site amplification factors at the northern part along the survey line were dominated in the frequency of 2-5Hz. It suggests that the ground profiles near the surface are complicate along this north-south survey line in the Kumamoto Plain. Therefore, we performed array microtremor observations at the temporary seismic stations, to estimate S-wave velocity structures along the north-south survey line. We obtained phase velocities of Rayleigh waves by the SPAC method and estimated S-wave velocity structures by applying the Genetic Algorism to those phase velocity. The low velocity layer with a thickness of around 15m was deposited on the surface at sites located in the alluvial lowland. Finally, we compared the distribution of PGAs observed along the north-south survey line to AVs30 estimated by S-wave velocity structures. As a result, PGAs along the survey line were strongly concerned by AVs30. We concluded that earthquake ground motions in the frequency of more than 1Hz observed in this north-south survey line were excited by the low velocity layer near the surface.

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

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    Lucio Martarelli


    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.

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


    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

  3. Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A (United States)

    Diane De Steven; Stephen P. Faulkner; Bobby D. Keeland; Michael J. Baldwin; John W. McCoy; Steven C. Hughes


    In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespread conversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs have attempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (...

  4. Electrical Resistivity Tomography and Induced Polarization for Mapping the Subsurface of Alluvial Fans: A Case Study in Punata (Bolivia

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    Andres Gonzales Amaya


    Full Text Available Conceptual models of aquifer systems can be refined and complemented with geophysical data, and they can assist in understanding hydrogeological properties such as groundwater storage capacity. This research attempts to use geoelectrical methods, Electrical Resistivity Tomography and Induced Polarization parameters, for mapping the subsurface in alluvial fans and to demonstrate its applicability; the Punata alluvial fan was used as a case study. The resistivity measurements proved to be a good tool for mapping the subsurface in the fan, especially when used in combination with Induced Polarization parameters (i.e., Normalized Chargeability. The Punata alluvial fan characterization indicated that the top part of the subsurface is composed of boulders in a matrix of finer particles and that the grain size decreases with depth; the electrical resistivity of these deposits ranged from 200 to 1000 Ωm, while the values of normalized chargeability were lower than 0.05 mS/m. The bottom of the aquifer system consisted of a layer with high clay content, and the resistivity ranged from 10 to 100 Ωm, while the normalized chargeability is higher than 0.07 mS/m. With the integration of these results and lithological information, a refined conceptual model is proposed; this model gives a more detailed description of the local aquifer system. It can be concluded that geoelectrical methods are useful for mapping aquifer systems in alluvial fans.

  5. A Comparison of Large-Scale Reforestation Techniques Commonly Used on Abandoned Fields in the Lower Mississippi Alluvial Vally (United States)

    Callie Jo Schweitzer; John A. Stanturf


    Reforesting abandoned land in the lower Mississippi alluvial valley has attracted heightened attention. Currently, federal cost share programs, such as the Wetland Reserve Program and the Conservation Reserve Program, are enticing landowners to consider reforesting lands that are marginally productive for agriculture. This study examined four reforestation techniques...

  6. Groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri, well field (United States)

    Wilkison, Donald H.


    Source contributions to monitoring and supply wells, contributing recharge areas, groundwater travel times, and current (2012) understanding of alluvial water quality were used to develop a groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri well field. The plan was designed to evaluate long-term alluvial water quality and assess potential changes in, and threats to, well-field water quality. Source contributions were determined from an existing groundwater flow model in conjunction with particle-tracking analysis and verified with water-quality data collected from 1997 through 2010 from a network of 68 monitoring wells. Three conjunctive factors - well-field pumpage, Missouri River discharge, and aquifer recharge - largely determined groundwater flow and, therefore, source contributions. The predominant source of groundwater to most monitoring wells and supply wells is the Missouri River, and this was reflected, to some extent, in alluvial water quality. To provide an estimate of the maximum potential lead time available for remedial action, monitoring wells where groundwater travel times from the contributing recharge areas are less than 2 years and predominately singular sources (such as the Missouri River or the land surface) were selected for annual sampling. The sample interval of the remaining wells, which have varying travel times and intermediate mixtures of river and land-surface contributions, were staggered on a 2-, 3-, or 4-year rotation. This was done to provide data from similar contributing areas and account for inherent aquifer variability yet minimize sample redundancy.

  7. Combined chemical and mineralogical evidence for heavy metal binding in mining- and smelting-affected alluvial soils-1

    Czech Academy of Sciences Publication Activity Database

    Vaněk, A.; Ettler, V.; Grygar, Tomáš; Borůvka, L.; Šebek, O.; Drábek, O.


    Roč. 18, č. 4 (2008), s. 464-478 ISSN 1002-0160 Institutional research plan: CEZ:AV0Z40320502 Keywords : alluvial soil * Fe and Mn axides * heavy metal s Subject RIV: CA - Inorganic Chemistry Impact factor: 0.865, year: 2008

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

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    Lu Zhang


    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.

  9. Economic potential of agroforestry and forestry in the lower Mississippi Alluvial Valley with incentive programs and carbon payments (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt


    Conversion of bottomland hardwood forests in the Lower Mississippi Alluvial Valley (LMAV) to agricultural land has caused a loss of ecosystem services. The primary approaches to reverse this have been the Wetlands Reserve Program and the Conservation Reserve Program, which provide financial incentives to landowners to reforest. However, other forest production regimes...

  10. Afforesting agricultural lands in the Mississippi Alluvial Valley (USA): effects of silvicultural methods on understory plant diversity (United States)

    Diane De Steven; Callie J. Schweitzer; Steven C. Hughes; John A. Stanturf


    To compare methods for bottomland hardwood reforestation on marginal farmlands in the Mississippi Alluvial Valley, four afforestation treatments (natural colonization, sown oak acorns, planted oak seedlings, cottonwood–oak interplant) were established in 1995 on former soybean cropland. Natural, sown, and planted-oak plots were not managed after establishment....

  11. Nursery stock quality as an indicator of bottomland hardwood forest restoration success in the Lower Mississippi River Alluvial Valley (United States)

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


    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...

  12. Determining the factors associated with seedling herbivory on afforested carbon sequestration sites in the Lower Mississippi Alluvial Valley: preliminary results (United States)

    Daniel C. Sumerall; Donald L. Grebner; Jeanne C. Jones; Stephen C. Grado; Richard P. Maiers; Keith L. Belli


    One causal factor of failed afforestation attempts in the Lower Mississippi Alluvial Valley (LMAV) is mammalian herbivory. Herbivory of seedlings generally reduces growth and can also lead to seedling mortality. Seedlings were randomly selected for monitoring throughout the first growing season. Growth and survival data were recorded, as were signs of mammalian...

  13. Large-scale comparison of reforestation techniques commonly used in the lower Mississippi alluvial valley: first year results (United States)

    Callie J. Schweitzer; John A. Stanturf; James P. Shepard; Timothy M. Wilkins; C. Jeffery Portwood; Lamar C., Jr. Dorris


    In the Lower Mississippi Alluvial Valley (LMAV), restoring bottomland hardwood forests has attracted heightened interest. The impetus involves not only environmental and aesthetic benefits, but also sound economics. Financial incentives to restore forested wetlands in the LMAV can come from federal cost share programs such as the Conservation Reserve Program and the...

  14. Plain Language Summary: Benign Paroxysmal Positional Vertigo. (United States)

    Bhattacharyya, Neil; Hollingsworth, Deena B; Mahoney, Kathryn; O'Connor, Sarah


    This plain language summary serves as an overview in explaining benign paroxysmal positional vertigo, abbreviated BPPV. This summary applies to patients ≥18 years old with a suspected or potential diagnosis of BPPV and is based on the 2017 "Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update)." The evidence-based guideline includes research to support more effective diagnosis and treatment of BPPV. The guideline was developed as a quality improvement opportunity for managing BPPV by creating clear recommendations to use in medical practice.

  15. Relating Hydrogeomorphic Attributes to Nutrient Uptake in Alluvial Streams of a Mountain Lake District (United States)

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


    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.

  16. Using oblique digital photography for alluvial sandbar monitoring and low-cost change detection (United States)

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


    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.

  17. Advance, Retreat, and Halt of Abrupt Gravel-Sand Transitions in Alluvial Rivers (United States)

    Blom, Astrid; Chavarrías, Víctor; Ferguson, Robert I.; Viparelli, Enrica


    Downstream fining of bed sediment in alluvial rivers is usually gradual, but often an abrupt decrease in characteristic grain size occurs from about 10 to 1 mm, i.e., a gravel-sand transition (GST) or gravel front. Here we present an analytical model of GST migration that explicitly accounts for gravel and sand transport and deposition in the gravel reach, sea level change, subsidence, and delta progradation. The model shows that even a limited gravel supply to a sand bed reach induces progradation of a gravel wedge and predicts the circumstances required for the gravel front to advance, retreat, and halt. Predicted modern GST migration rates agree well with measured data at Allt Dubhaig and the Fraser River, and the model qualitatively captures the behavior of other documented gravel fronts. The analysis shows that sea level change, subsidence, and delta progradation have a significant impact on the GST position in lowland rivers.

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

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    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.

  19. Steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system (United States)

    Brooks, Lynette E.; Masbruch, Melissa D.; Sweetkind, Donald S.; Buto, Susan G.


    This report describes the construction, calibration, evaluation, and results of a steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system that was developed as part of the U.S. Geological Survey National Water Census Initiative to evaluate the nation’s groundwater availability. The study area spans 110,000 square miles across five states. The numerical model uses MODFLOW-2005, and incorporates and tests complex hydrogeologic and hydrologic elements of a conceptual understanding of an interconnected groundwater system throughout the region, including mountains, basins, consolidated rocks, and basin fill. The level of discretization in this model has not been previously available throughout the study area.

  20. Benzene dynamics and biodegradation in alluvial aquifers affected by river fluctuations. (United States)

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


    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.

  1. The Importance of Bank Storage in Supplying Baseflow to Rivers Flowing Through Compartmentalized, Alluvial Aquifers (United States)

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


    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.

  2. Residence times and alluvial architecture of a sediment superslug in response to different flow regimes (United States)

    Moody, John A.


    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

  3. The equilibrium alluvial river under variable flow and its channel-forming discharge (United States)

    Blom, Astrid; Arkesteijn, Liselot; Chavarrías, Víctor; Viparelli, Enrica


    When the water discharge, sediment supply, and base level vary around stable values, an alluvial river evolves toward a mean equilibrium or graded state with small fluctuations around this mean state (i.e., a dynamic or statistical equilibrium state). Here we present analytical relations describing the mean equilibrium geometry of an alluvial river under variable flow by linking channel slope, width, and bed surface texture. The solution holds in river normal flow zones (or outside both the hydrograph boundary layer and the backwater zone) and accounts for grain size selective transport and particle abrasion. We consider the variable flow rate as a series of continuously changing yet steady water discharges (here termed an alternating steady discharge). The analysis also provides a solution to the channel-forming water discharge, which is here defined as the steady water discharge that, given the mean sediment supply, provides the same equilibrium channel slope as the natural long-term hydrograph. The channel-forming water discharge for the gravel load is larger than the one associated with the sand load. The analysis illustrates how the load is distributed over the range of water discharge in the river normal flow zone, which we term the "normal flow load distribution". The fact that the distribution of the (imposed) sediment supply spatially adapts to this normal flow load distribution is the origin of the hydrograph boundary layer. The results quantify the findings by Wolman and Miller (1960) regarding the relevance of both magnitude and frequency of the flow rate with respect to channel geometry.

  4. Inference of lithologic distributions in an alluvial aquifer using airborne transient electromagnetic surveys (United States)

    Dickinson, Jesse E.; Pool, D.R.; Groom, R.W.; Davis, L.J.


    An airborne transient electromagnetic (TEM) survey was completed in the Upper San Pedro Basin in southeastern Arizona to map resistivity distributions within the alluvial aquifer. This investigation evaluated the utility of 1D vertical resistivity models of the TEM data to infer lithologic distributions in an alluvial aquifer. Comparisons of the resistivity values and layers in the 1D resistivity models of airborne TEM data to 1D resistivity models of ground TEM data, borehole resistivity logs, and lithologic descriptions in drill logs indicated that the airborne TEM identified thick conductive fine-grained sediments that result in semiconfined groundwater conditions. One-dimensional models of ground-based TEM surveys and subsurface lithology at three sites were used to determine starting models and constraints to invert airborne TEM data using a constrained Marquardt-styleunderparameterized method. A maximum structural resolution of six layers underlain by a half-space was determined from the resistivity structure of the 1D models of the ground TEM data. The 1D resistivity models of the airborne TEM data compared well with the control data to depths of approximately 100 m in areas of thick conductive silt and clay and to depths of 200 m in areas of resistive sand and gravel. Comparison of a 3D interpolation of the 1D resistivity models to drill logs indicated resistive (mean of 65 ohm-m ) coarse-grained sediments along basin margins and conductive (mean of 8 ohm-m ) fine-grained sediments at the basin center. Extents of hydrologically significant thick silt and clay were well mapped by the 1D resistivity models of airborne TEM data. Areas of uncertain lithology remain below conductive fine-grained sediments where the 1D resistivity structure is not resolved: in areas where multiple lithologies have similar resistivity values and in areas of high salinity.

  5. 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.


    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.

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


    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

  7. Environment tracers application to groundwater circulation assessment in an alluvial aquifer in Central Italy (United States)

    Sappa, Giuseppe; Barbieri, Maurizio; Vitale, Stefania


    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

  8. Geologic and physiographic controls on bed-material yield, transport, and channel morphology for alluvial and bedrock rivers, western Oregon (United States)

    O'Connor, James E.; Mangano, Joseph F.; Anderson, Scott A.; Wallick, J. Rose; Jones, Krista L.; Keith, Mackenzie K.


    The rivers of western Oregon have diverse forms and characteristics, with channel substrates ranging from continuous alluvial gravel to bare bedrock. Analysis of several measurable morphologic attributes of 24 valley reaches on 17 rivers provides a basis for comparing nonalluvial and alluvial channels. Key differences are that alluvial reaches have greater bar area, greater migration rates, and show systematic correlation among variables relating grain size to bed-material transport capacity. We relate these differences between channel types to bed-material transport rates as derived from a coupled regional analysis of empirical sediment yield measurements and physical experiments of clast attrition during transport. This sediment supply analysis shows that overall bed-material transport rates for western Oregon are chiefly controlled by (1) lithology and basin slope, which are the key factors for bed-material supply into the stream network, and (2) lithologic control of bed-material attrition from in-transport abrasion and disintegration. This bed-material comminution strongly affects bed-material transport in the study area, reducing transport rates by 50%–90% along the length of the larger rivers in the study area. A comparison of the bed-material transport estimates with the morphologic analyses shows that alluvial gravel-bed channels have systematic and bounding relations between bed-material transport rate and attributes such as bar area and local transport capacity. By contrast, few such relations are evident for nonalluvial rivers with bedrock or mixed-bed substrates, which are apparently more influenced by local controls on channel geometry and sediment supply. At the scale of western Oregon, the physiographic and lithologic controls on the balance between bed-material supply and transport capacity exert far-reaching influence on the distribution of alluvial and nonalluvial channels and their consequently distinctive morphologies and behaviors

  9. Plain chest radiographic findings of smoke inhalation

    International Nuclear Information System (INIS)

    Lee, Shin Ho; Lee, Eil Weong; Kim, Hyun Suk; Park, Ju Youn; Kim, Soo Hyun; Hong, Sung Hwan; Park, Hong Suk; Lee, Kwan Seop; Kang Ik Won


    To evaluate the plain chest radiographic findings of smoke inhalation. Our study included 72 burn patients who had suffered smoke inhalation. On admission, all underwent serial portable chest AP radiography. We retrospectively reviewed the plain chest radiographs taken between admission and pootburn day five, evaluating the pattern, distribution, and time onset of direct injury to the respiratory system by smoke inhalation. The lesions were also assessed for change. In 16 of 72 patients (22%), abnormal findings of direct injury to the respiratory system by smoke inhalation were revealed by the radiographs. Abnormal findings were 15 pulmonary lesions and one subglottic tracheal narrowing. Findings of pulmonary lesions were multiple small patchy consolidations (10/15), peribronchial cuffing (8/15), and perivascular fuzziness (6/15). Patterns of pulmonary lesions were mixed alveolar and interstitial lesion (n=3D9), interstitial lesion (n=3D5), and alveolar lesion (n=3D1). No interlobular septal thickening was observed. Pulmonary edema was distributed predominantly in the upper lung zone and perihilar region, with asymmetricity. Its time of onset was within 24 hours in 13 cases, 24-48 hours in two cases, and 48-72 hours in one. Five of 16 patients progressed to ARDS. Chest radiographs showed that pulmonary lesions caused by inhalation injury were due to pulmonary edema, which the pattern of which was commonly mixed alveolar and interstitial. (author)

  10. 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.


    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

  11. 18 CFR 801.8 - Flood plain management and protection. (United States)


    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flood plain management... COMMISSION GENERAL POLICIES § 801.8 Flood plain management and protection. (a) Periodic inundation of lands along waterways has not discouraged development of flood hazards areas. Major floods cause loss of life...

  12. Dermatology nursing in the community: The Mitchell's Plain ...

    African Journals Online (AJOL)

    250 CME July 2013 Vol. 31 No. 7. Dermatology nursing in the community: The Mitchell's Plain experience. Dermatology is an important element of community nursing. J Stevens, RN, RM, CPN, PG Dip Derm Nursing. Clinical and Dermatology Nurse Practitioner, Mitchell's Plain Community Health Centre, Cape Town, South ...

  13. Analyzing the Various Approaches of Plain Language Laws. (United States)

    Bowen, Betsy A., And Others


    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)

  14. 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 ...

  15. Multi-approach assessment of the spatial distribution of the specific yield: application to the Crau plain aquifer, France (United States)

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


    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.

  16. 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.


    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

  17. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate (United States)

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


    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

  18. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate. (United States)

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


    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

  19. Groundwater recharge and agricultural contamination in alluvial fan of Eastern Kofu basin, JAPAN (United States)

    Nakamura, T.


    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

  20. Alluvial groundwater recharge estimation in semi-arid environment using remotely sensed data (United States)

    Coelho, Victor Hugo R.; Montenegro, Suzana; Almeida, Cristiano N.; Silva, Bernardo B.; Oliveira, Leidjane M.; Gusmão, Ana Cláudia V.; Freitas, Emerson S.; Montenegro, Abelardo A. A.


    Data limitations on groundwater (GW) recharge over large areas are still a challenge for efficient water resource management, especially in semi-arid regions. Thus, this study seeks to integrate hydrological cycle variables from satellite imagery to estimate the spatial distribution of GW recharge in the Ipanema river basin (IRB), which is located in the State of Pernambuco in Northeast Brazil. Remote sensing data, including monthly maps (2011-2012) of rainfall, runoff and evapotranspiration, are used as input for the water balance method within Geographic Information Systems (GIS). Rainfall data are derived from the TRMM Multi-satellite Precipitation Analysis (TMPA) Version 7 (3B43V7) product and present the same monthly average temporal distributions from 15 rain gauges that are distributed over the study area (r = 0.93 and MAE = 12.7 mm), with annual average estimates of 894.3 (2011) and 300.7 mm (2012). The runoff from the Natural Resources Conservation Service (NRCS) method, which is based on regional soil information and Thematic Mapper (TM) sensor image, represents 29% of the TMPA rainfall that was observed across two years of study. Actual evapotranspiration data, which were provided by the SEBAL application of MODIS images, present annual averages of 1213 (2011) and 1067 (2012) mm. The water balance results reveal a large inter-annual difference in the IRB GW recharge, which is characterized by different rainfall regimes, with averages of 30.4 (2011) and 4.7 (2012) mm year-1. These recharges were mainly observed between January and July in regions with alluvial sediments and highly permeable soils. The GW recharge approach with remote sensing is compared to the WTF (Water Table Fluctuation) method, which is used in an area of alluvium in the IRB. The estimates from these two methods exhibit reliable annual agreement, with average values of 154.6 (WTF) and 124.6 (water balance) mm in 2011. These values correspond to 14.89 and 13.53% of the rainfall that was

  1. Changes in alluvial architecture associated with Eocene hyperthermals: Preliminary results from the Bighorn Basin Coring Project (United States)

    Acks, R.; Kraus, M. J.


    The Paleocene-Eocene Thermal Maximum (PETM) was followed by two lesser hyperthermal events: ETM2 and H2 both at ~53.7 Ma. The carbon isotope excursion for ETM2 was approximately half that of the PETM and the H2 excursion even smaller, indicating lower increases in temperature than during the PETM. The paleohydrologic responses to these events are less well understood than the response to PETM warming. Although the ETM2 and H2 events are better known from marine than continental strata, both events have been identified from outcrops of the alluvial Willwood Formation from the Deer Creek and Gilmore Hill areas of the Bighorn Basin, Wyoming (Abels et al., 2012). Here, we analyze two cores drilled from stratigraphically equivalent Willwood strata from Gilmore Hill. The cores provide an opportunity to examine the impact of these events on the architecture of fluvial strata. Willwood strata are composed largely of channel sandstones, heterolithic deposits generated by channel avulsion, and paleosols that formed on overbank deposits. The paleosols provide qualitative and quantitative information on changes in soil moisture and precipitation through this interval. The cores also show a distinct change in the stacking of paleosols The core is subdivided into three parts: (1) the lowest ~third has thinner, more densely spaced paleosols, (2) the middle has thicker paleosols that are more widely spaced, and (3) the upper third has thicker and more common channel sandstones interspersed with avulsion deposits and fewer red paleosols; this corresponds to the hyperthermal interval. In particular, a ~20 m thick sandstone complex caps the section and appears to truncate part of the hyperthermal interval. Although vertical variations in alluvial architecture can reflect tectonic or climatic change, the correspondence of the sandstone-rich part of the cores with the hyperthermals suggests climate was the major control on their formation. Thick purple paleosols associated with the

  2. Landscape level reforestation priorities for forest breeding landbirds in the Mississippi Alluvial Valley (United States)

    Twedt, D.J.; Uihlein, W.B.; Fredrickson, L.H.; King, S.L.; Kaminski, R.M.


    Thousands of ha of cleared wetlands are being reforested annually in the Mississippi Alluvial Valley (MAV). Despite the expansive and long-term impacts of reforestation on the biological communities of the MAV, there is generally a lack of landscape level planning in its implementation. To address this deficiency we used raster-based digital data to assess the value of forest restoration to migratory landbirds for each ha within the MAV. Raster themes were developed that reflected distance from 3 existing forest cover parameters: (1) extant forest, (2) contiguous forest patches between 1,012 and 40,000 ha, and (3) forest cores with contiguous area 1 km from an agricultural, urban, or pastoral edge. Two additional raster themes were developed that combined information on the proportion of forest cover and average size of forest patches, respectively, within landscapes of 50,000, 100,000, 150,000, and 200,000 ha. Data from these 5 themes were amalgamated into a single raster using a weighting system that gave increased emphasis to existing forest cores, larger forest patches, and moderately forested landscapes while deemphasizing reforestation near small or isolated forest fragments and within largely agricultural landscapes. This amalgamated raster was then modified by the geographic location of historical forest cover and the current extent of public land ownership to assign a reforestation priority score to each ha in the MAV. However, because reforestation is not required on areas with extant forest cover and because restoration is unlikely on areas of open water and urban communities, these lands were not assigned a reforestation priority score. These spatially explicit reforestation priority scores were used to simulate reforestation of 368,000 ha (5%) of the highest priority lands in the MAV. Targeting restoration to these high priority areas resulted in a 54% increase in forest core - an area of forest core that exceeded the area of simulated reforestation

  3. Analysis of the Carmel Valley alluvial ground-water basin, Monterey County, California (United States)

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


    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

  4. Radon and thoron levels, their spatial and seasonal variations in adobe dwellings - a case study at the great Hungarian plain. (United States)

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


    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.

  5. 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.


    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.

  6. 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.


    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

  7. 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


    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

  8. Late Quaternary alluvial fans of Emli Valley in the Ecemiş Fault Zone, south central Turkey: Insights from cosmogenic nuclides (United States)

    Akif Sarıkaya, M.; Yıldırım, Cengiz; Çiner, Attila


    Alluvial fans within the paraglacial Ecemiş River drainages on the Aladağlar Mountains in south central Turkey were studied using geomorphological, sedimentological, and chlorine-36 terrestrial cosmogenic nuclide (TCN) surface exposure dating methods to examine the timing of alluvial fan abandonment/incision, and to understand the role of climatic and tectonic processes in the region. These alluvial fan complexes are among the best-preserved succession of alluvial fans in Turkey and they were offset by the major strike-slip Ecemiş Fault of the Central Anatolian Fault Zone. The alluvial fans are mostly composed of well-lithified limestone cobbles (5 to 25 cm in size), and comprise crudely stratified thick beds with a total thickness reaching up to about 80 m. TCN surface exposure dating indicates that the oldest alluvial fan surface (Yalak Fan) was likely formed and subsequently abandoned latest by 136.0 ± 23.4 ka ago, largely on the transition of the Penultimate Glaciation (Marine Isotope Stage 6, MIS 6) to the Last Interglacial (MIS 5) (i.e. Termination II). The second set of alluvial fan (Emli Fan) was possibly developed during the Last Interglacial (MIS 5), and incised twice by between roughly 97.0 ± 13.8 and 81.2 ± 13.2 ka ago. A younger alluvial fan deposit placed on relatively older erosional terraces of the Emli Fan suggests that it may have been produced during the Last Glacial Cycle (MIS 2). These events are similar to findings from other fluvial and lacustrine deposits throughout central Anatolia. The incision times of the Ecemiş alluvial fan surfaces largely coincide with major climatic shifts from the cooler glacial periods to warmer interglacial/interstadial conditions. This indicates that alluvial fans were produced by outwash sediments of paleoglaciers during cooler conditions, and, later, when glaciers started to retreat due to a major warming event, the excess water released from the glaciers incised the pre-existing fan surfaces. An

  9. Chemical weathering outputs from the flood plain of the Ganga (United States)

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


    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 caused by dissolution of Na carbonate salts. The compositions of the carbonate and silicate components of the sediments were determined from sequential leaches of floodplain bedloads and these were used to partition the dissolved cation load between silicate and carbonate sources. The 87Sr/86Sr and Sr/Ca ratios of the carbonate inputs were derived from the acetic-acid leach compositions and silicate Na/Ca and 87Sr/86Sr ratios derived from

  10. Risk assessment of heavy metal pollution in alluvial soils and sediments of the Grote Beek river (Belgium)


    Cappuyns, Valérie; Swennen, Rudy


    Consoil 2003 RISK ASSESSMENT OF HEAVY METAL POLLUTION IN ALLUVIAL SOILS AND SEDIMENTS OF THE GROTE BEEK RIVER (BELGIUM) Valérie Cappuyns, Rudy Swennen and Katrien De Nil Katholieke Universiteit Leuven, Fysico-chemische Geologie, Celestijnenlaan 200C, 3001 Heverlee, Belgium Tel. +3216327297, Fax. +3216327981, e-mail: 1. Introduction Wastewater discharge from the processing of phosphate ores has contributed to pollution by heavy metals ...

  11. Plain packaging of cigarettes: do we have sufficient evidence? (United States)

    Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren


    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.

  12. Tobacco plain packaging: Evidence based policy or public health advocacy? (United States)

    McKeganey, Neil; Russell, Christopher


    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.

  13. 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.


    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)

  14. Lithology, hydrologic characteristics, and water quality of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas (United States)

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


    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.

  15. Biodegradation of petroleum hydrocarbon vapors: laboratory studies on rates and kinetics in unsaturated alluvial sand (United States)

    Höhener, Patrick; Duwig, Céline; Pasteris, Gabriele; Kaufmann, Karin; Dakhel, Nathalie; Harms, Hauke


    Predictions of natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone rely critically on information about microbial biodegradation kinetics. This study aims at determining kinetic rate laws for the aerobic biodegradation of a mixture of 12 volatile petroleum hydrocarbons and methyl tert-butyl ether (MTBE) in unsaturated alluvial sand. Laboratory column and batch experiments were performed at room temperature under aerobic conditions, and a reactive transport model for VOC vapors in soil gas coupled to Monod-type degradation kinetics was used for data interpretation. In the column experiment, an acclimatization of 23 days took place before steady-state diffusive vapor transport through the horizontal column was achieved. Monod kinetic parameters Ks and vmax could be derived from the concentration profiles of toluene, m-xylene, n-octane, and n-hexane, because substrate saturation was approached with these compounds under the experimental conditions. The removal of cyclic alkanes, isooctane, and 1,2,4-trimethylbenzene followed first-order kinetics over the whole concentration range applied. MTBE, n-pentane, and chlorofluorocarbons (CFCs) were not visibly degraded. Batch experiments suggested first-order disappearance rate laws for all VOCs except n-octane, which decreased following zero-order kinetics in live batch experiments. For many compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches indicating sorption. It was concluded that the column approach is preferable for determining biodegradation rate parameters to be used in risk assessment models.

  16. Autogenic entrenchment patterns and terraces due to coupling with lateral erosion in incising alluvial channels (United States)

    Malatesta, Luca C.; Prancevic, Jeffrey P.; Avouac, Jean-Philippe


    The abandonment of terraces in incising alluvial rivers can be used to infer tectonic and climatic histories. A river incising into alluvium erodes both vertically and laterally as it abandons fill-cut terraces. We argue that the input of sediment from the valley walls during entrenchment can alter the incision dynamics of a stream by promoting vertical incision over lateral erosion. Using a numerical model, we investigate how valley wall feedbacks may affect incision rates and terrace abandonment as the channel becomes progressively more entrenched in its valley. We postulate that erosion of taller valley walls delivers large pulses of sediment to the incising channel, potentially overwhelming the local sediment transport capacity. Based on field observations, we propose that these pulses of sediment can form talus piles that shield the valley wall from subsequent erosion and potentially force progressive channel narrowing. Our model shows that this positive feedback mechanism can enhance vertical incision relative to 1-D predictions that ignore lateral erosion. We find that incision is most significantly enhanced when sediment transport rates are low relative to the typical volume of material collapsed from the valley walls. The model also shows a systematic erosion of the youngest terraces when river incision slows down. The autogenic entrenchment due to lateral feedbacks with valley walls should be taken into account in the interpretation of complex-response terraces.

  17. Balancing lake ecological condition and agriculture irrigation needs in the Mississippi Alluvial Valley (United States)

    Miranda, Leandro E.; Omer, A.R.; Killgore, K.J.


    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.

  18. Influence of hydrologic modifications on Fraxinus pennsylvanica in the Mississippi River Alluvial Valley, USA (United States)

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.


    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.

  19. Sedimentology and paleoecology of an Eocene Oligocene alluvial lacustrine arid system, Southern Mexico (United States)

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


    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.

  20. The importance of fluvial hydraulics to fish-habitat restoration in low-gradient alluvial streams (United States)

    Rabeni, Charles F.; Jacobson, Robert B.


    1. A major cause of degradation and loss of stream fish is alteration of physical habitat within and adjacent to the channel. We describe a potentially efficient approach to fish restoration based upon the relationship between fluvial hydraulics, geomorphology, and those habitats important to fish.2. The aquatic habitat in a low-gradient, alluvial stream in the Ozark Plateaus physiographical province was classified according to location in the channel, patterns of water flow, and structures that control flow. The resulting habitat types were ranked in terms of their temporal stability and ability to be manipulated.3. Delineation and quantification of discrete physical spaces in a stream, termed hydraulic habitat units, are shown to be useful in stream restoration programmes if the ecological importance of each habitat unit is known, and if habitats are defined by fluvial dynamics so that restoration is aided by natural forces.4. Examples, using different taxa, are given to illustrate management options.

  1. The Lower Cretaceous Way Group of northern Chile: An alluvial fan-fan delta complex (United States)

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


    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.

  2. Reactive transport in the complex heterogeneous alluvial aquifer of Fortymile Wash, Nevada. (United States)

    Soltanian, Mohamad Reza; Sun, Alexander; Dai, Zhenxue


    Yucca Mountain, Nevada, had been extensively investigated as a potential deep geologic repository for storing high-level nuclear wastes. Previous field investigations of stratified alluvial aquifer downstream of the site revealed that there is a hierarchy of sedimentary facies types. There is a corresponding log conductivity and reactive surface area subpopulations within each facies at each scale of sedimentary architecture. Here we use a Lagrangian-based transport model in order to analyze radionuclide dispersion in the saturated alluvium of Fortymile Wash, Nevada. First, we validate the Lagrangian model using high-resolution flow and reactive transport simulations. Then, we used the validated model to investigate how each scale of sedimentary architecture may affect long-term radionuclide transport at Yucca Mountain. Results show that the reactive solute dispersion developed by the Lagrangian model matches the ensemble average of numerical simulations well. The link between the alluvium spatial variability and reactive solute dispersion at different spatiotemporal scales is demonstrated using the Lagrangian model. The longitudinal dispersivity of the reactive plume can be on the order of hundreds to thousands of meters, and it may not reach its asymptotic value even after 10,000 years of travel time and 2-3 km of travel distance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer (United States)

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


    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.

  4. Using solute and heat tracers for aquifer characterization in a strongly heterogeneous alluvial aquifer (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    K. Edmaier


    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.

  6. Alluvial substrate mapping by automated texture segmentation of recreational-grade side scan sonar imagery. (United States)

    Hamill, Daniel; Buscombe, Daniel; Wheaton, Joseph M


    Side scan sonar in low-cost 'fishfinder' systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilometers of channel in a few hours. Towards a goal of automating the classification of bed habitat features, we investigate relationships between substrates and statistical descriptors of bed textures in side scan sonar echograms of alluvial deposits. We develop a method for automated segmentation of bed textures into between two to five grain-size classes. Second-order texture statistics are used in conjunction with a Gaussian Mixture Model to classify the heterogeneous bed into small homogeneous patches of sand, gravel, and boulders with an average accuracy of 80%, 49%, and 61%, respectively. Reach-averaged proportions of these sediment types were within 3% compared to similar maps derived from multibeam sonar.

  7. Valuing ecosystem services from wetlands restoration in the Mississippi Alluvial Valley (United States)

    Jenkins, W.A.; Murray, B.C.; Kramer, R.A.; Faulkner, S.P.


    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.

  8. River banks and channel axis curvature: Effects on the longitudinal dispersion in alluvial rivers (United States)

    Lanzoni, Stefano; Ferdousi, Amena; Tambroni, Nicoletta


    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. Modeling ground water flow in alluvial mountainous catchments on a watershed scale. (United States)

    Wolf, Jens; Barthel, Roland; Braun, Jürgen


    In large mountainous catchments, shallow unconfined alluvial aquifers play an important role in conveying subsurface runoff to the foreland. Their relatively small extent poses a serious problem for ground water flow models on the river basin scale. River basin scale models describing the entire water cycle are necessary in integrated water resources management and to study the impact of global climate change on ground water resources. Integrated regional-scale models must use a coarse, fixed discretization to keep computational demands low and to facilitate model coupling. This can lead to discrepancies between model discretization and the geometrical properties of natural systems. Here, an approach to overcome this discrepancy is discussed using the example of the German-Austrian Upper Danube catchment, where a coarse ground water flow model was developed using MODFLOW. The method developed uses a modified concept from a hydrological catchment drainage analysis in order to adapt the aquifer geometry such that it respects the numerical requirements of the chosen discretization, that is, the width and the thickness of cells as well as gradients and connectivity of the catchment. In order to show the efficiency of the developed method, it was tested and compared to a finely discretized ground water model of the Ammer subcatchment. The results of the analysis prove the applicability of the new approach and contribute to the idea of using physically based ground water models in large catchments.

  10. Calcretes in semi-arid alluvial systems: formative pathways and sinks (United States)

    Khadkikar, A. S.; Merh, S. S.; Malik, J. N.; Chamyal, L. S.


    Late Quaternary deposits in Gujarat, western India show an abundant development of calcretes. Three major sinks of carbonate in the alluvial deposits are recognized: (1) groundwater calcretes, (2) pedogenic calcretes, and (3) calcrete conglomerates. Groundwater calcretes originate from carbonate-saturated waters travelling preferentially along stratification planes. Pedogenic calcretes form through soil-forming processes typically in extra-channel areas. Calcrete conglomerates occur as ribbons, sheets and lenses due to the reworking of both pedogenic as well as groundwater calcretes. As a result a pathway of calcretization develops that has the route: groundwater calcrete to pedogenic calcrete to calcrete-conglomerate. The formation of pedogenic calcretes over sediments containing groundwater calcretes demonstrates that (1) apart from aeolian dust, river waters are also a major source of carbonate, and (2) pedogenic carbonates may attain large sizes at accelerated rates due to the presence of pre-existing groundwater calcretes. Consequently, the maturity of a soil may be overestimated if determined by following established morphogenetic sequences.

  11. 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


    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

  12. An Investigation of the Uniaxial Compressive Strength of a Cemented Hydraulic Backfill Made of Alluvial Sand

    Directory of Open Access Journals (Sweden)

    Guangsheng Liu


    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.

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

    Directory of Open Access Journals (Sweden)

    Kamal Mohamed Hafez Ismail Ibrahim


    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.

  14. Depositional processes of alluvial fans along the Hilina Pali fault scarp, Island of Hawaii (United States)

    Morgan, Alexander M.; Craddock, Robert A.


    A series of previously unstudied alluvial fans are actively forming along the Hilina Pali escarpment on the south flank of Kīlauea volcano on the Island of Hawaii. These fans are characterized by their steep slopes, coarse grain sizes, and lobate surface morphology. Fans are fed by bedrock channels that drain from the Ka'ū Desert, but sediment is mostly sourced from deeply eroded alcoves carved into the Hilina Pali. Examination of recent deposits indicates that the fans are dominantly constructed from gravel and larger sized sediment. Flow discharges calculated using field measurements of channel geometries and the Manning equation indicate that events inducing sediment transport are of high magnitude and occur during high intensity precipitation events, including Kona storms. The fans along the Hilina Pali appear to be a rare example of fans formed predominately from sieve lobe deposition owing to the area's high slopes, high discharge, coarse bedload, and limited supply of fine-grained sediment. Given such conditions, sieve lobe deposition can form large lobes consisting of boulder-sized material, which may have implications for the identification of depositional processes when interpreting the stratigraphic record.

  15. A field study of nonequilibrium and facilitated transport of Cd in an alluvial gravel aquifer. (United States)

    Pang, L; Close, M


    A natural-gradient tracer experiment was conducted to study Cd transport in an alluvial gravel aquifer. Both a conservative tracer and Cd exhibited tailing in their breakthrough curves (BTCs), indicating the presence of nonequilibrium transport. Solute transport was evaluated using a three-dimensional nonequilibrium analytical model, and the results were compared with those obtained from a previous laboratory study. At similar flow velocities, the field Cd data gave significantly lower retardation factors (R=7 to 30, median 22), higher fractions of instantaneous sorption sites (beta), and greater mass transfer coefficients (omega) than the laboratory data because of a high degree of aquifer heterogeneity, the presence of preferential flow, and the larger transport scale in the field conditions. Multiple peaks in the Cd BTCs were observed due to bacteria-facilitated and perhaps also colloid-facilitated transport. The early peaks showed narrower, more symmetric shapes with higher concentrations than the later peaks, and compared well to those of the bacterial BTCs. The multiple peaks of the Cd BTCs imply that a significant fraction of Cd could travel with little, if any, retardation over a 20 to 40 m travel distance when Cd and bacteria coexist in a contamination event.

  16. 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


    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.

  17. Cadmium accumulation and growth responses of a poplar (Populus deltoidsxPopulus nigra) in cadmium contaminated purple soil and alluvial soil. (United States)

    Wu, Fuzhong; Yang, Wanqin; Zhang, Jian; Zhou, Liqiang


    To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoidsxPopulus 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 microg 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. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  18. Sustainable Authorship in Plain Text using Pandoc and Markdown

    Directory of Open Access Journals (Sweden)

    Dennis Tenen


    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.

  19. Ius Chasma Tributary Valleys and Adjacent Plains (United States)


    This image covers valley tributaries of Ius Chasma, as well as the plains adjacent to the valleys. Ius Chasma is one of several canyons that make up the Valles Marineris canyon system. Valles Marineris likely formed by extension associated with the growth of the large volcanoes and topographic high of Tharsis to the northwest. As the ground was pulled apart, large and deep gaps resulted in the valleys seen in the top and bottom of this HiRISE image. Ice that was once in the ground could have also melted to create additional removal of material in the formation of the valleys. HiRISE is able to see the rocks along the walls of both these valleys and also impact craters in the image. Rock layers that appear lower down in elevation appear rougher and are shedding boulders. Near the top of the walls and also seen in patches along the smooth plains are brighter layers. These brighter layers are not shedding boulders so they must represent a different kind of rock formed in a different kind of environment than those further down the walls. Because they are highest in elevation, the bright layers are youngest in age. HiRISE is able to see dozens of the bright layers, which are perhaps only a meter in thickness. Darker sand dunes and ripples cover most of the plains and fill the floors of impact craters. Image PSP_001351_1715 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 9, 2006. The complete image is centered at -8.3 degrees latitude, 275.4 degrees East longitude. The range to the target site was 254.3 km (158.9 miles). At this distance the image scale ranges from 25.4 cm/pixel (with 1 x 1 binning) to 101.8 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 3:32 PM and the scene is illuminated from the west with a solar incidence angle of 59 degrees, thus the sun was about 31

  20. San Andreas Fault in the Carrizo Plain (United States)


    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

  1. Great Plains Wind Energy Transmission Development Project

    Energy Technology Data Exchange (ETDEWEB)

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


    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

  2. Late Quaternary palaeoenvironmental changes documented by microfaunas and shell stable isotopes in the southern Pearl River Delta plain, South China

    Directory of Open Access Journals (Sweden)

    Liu Chunlian


    alluvial plain setting.

  3. Placentation in the plains zebra (Equus quagga). (United States)

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


    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.

  4. Nonlinear Dynamical Analysis for a Plain Bearing

    Directory of Open Access Journals (Sweden)

    Ali Belhamra


    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.

  5. Moessbauer studies on ancient Jizhon plain Temmoku porcelains

    International Nuclear Information System (INIS)

    Yu Zhengfang; Zheng Yufang; Lin Yongqiang


    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.)

  6. Study on ecological regulation of coastal plain sluice (United States)

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


    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.

  7. Types, harms and improvement of saline soil in Songnen Plain (United States)

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


    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.

  8. Recognition of Plain Objects Using Local Region Matching (United States)

    Mansur, Al; Sakata, Katsutoshi; Das, Dipankar; Kuno, Yoshinori

    Conventional interest point based matching requires computationally expensive patch preprocessing and is not appropriate for recognition of plain objects with negligible detail. This paper presents a method for extracting distinctive interest regions from images that can be used to perform reliable matching between different views of plain objects or scene. We formulate the correspondence problem in a Naive Bayesian classification framework and a simple correlation based matching, which makes our system fast, simple, efficient, and robust. To facilitate the matching using a very small number of interest regions, we also propose a method to reduce the search area inside a test scene. Using this method, it is possible to robustly identify objects among clutter and occlusion while achieving near real-time performance. Our system performs remarkably well on plain objects where some state-of-the art methods fail. Since our system is particularly suitable for the recognition of plain object, we refer to it as Simple Plane Object Recognizer (SPOR).

  9. Intracavitary pulmonary aspergilloma: comparison of CT with plain chest radiograph

    International Nuclear Information System (INIS)

    Han, Chun Hwan; Im, Jung Gi; Yu, Eun Ju; Han, Man Chung


    Saprophytic intracavitary fungus ball is the most common form of pulmonary involvement of aspergillosis. Crescent-shaped air shadow surrounded by a creativity wall is known to be a characteristic of pulmonary aspergilloma on plain chest radiograph. However, in case of early lesion in which intracavitary aspergilloma is overlapped with adjacent destroyed lung or mediastinal and hilar density, the air meniscus can not be demonstrated on plain radiograph. In such a case, CT scan might provide additional information that suggests fungus ball. The aim of this study is to describe the variable CT appearances of pulmonary aspergilloma in addition to air meniscus sign and to correlate the findings on CT with those of plain radiograph and pathology. The diagnosis of intracavitary aspergilloma was suggested on both CT and plain radiograph in case that air-meniscus sign was visible. CT scans could add more diagnostic information over chest radiographs such as small peripheral air density or sponge-like air shadow

  10. 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)


    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.

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

    International Nuclear Information System (INIS)

    Yang Xiaowei


    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)

  12. The Great Plains IDEA Gerontology Program: An Online, Interinstitutional Graduate Degree (United States)

    Sanders, Gregory F.


    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…

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


    Alain Pottage


    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...

  14. Perceptions of branded and plain cigarette packaging among Mexican youth. (United States)

    Mutti, Seema; Hammond, David; Reid, Jessica L; White, Christine M; Thrasher, James F


    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:

  15. Plain packaging of cigarettes: do we have sufficient evidence? (United States)

    Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren


    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

  16. Eco-environmental quality evaluation of Huaibei Plain (United States)

    Xu, M.; Zhu, Y.; Lü, H.; Li, Y.; Zhou, X.; Chen, Y.


    In recent years, the destruction of the ecological environment in Huaibei Plain has limited the development of the economy. Doing research on eco-environment quality evaluation methods may be helpful to the recovery of the eco-environment in Huaibei Plain and the construction of ecological civilization. A new assessment system was introduced in this paper on the basis of a traditional eco-environmental evaluation method; the NPP index was used to replace biological abundance index and vegetation coverage index. This new method was used to evaluate the eco-environment quality of Huaibei Plain. Results indicate that: (a) the eco-environment of Huaibei Plain has been getting worse since 1990, but has improved since 2000; (b) the water-network density index is the key factor which affects the eco-environment of Huaibei Plain; (c) If human activities, pollution control, land degradation and urban area development are not taken into consideration, the eco-environment of Huaibei Plain in dry years will be serious.

  17. Modelling the Holocene Evolution of a Drift-dominated Alluvial-fan Coast (United States)

    Hicks, M.; Dickson, M.; Coco, G.


    A numerical model is being developed to simulate shore evolution along an alluvial fan coast over the Holocene. The alluvial fan of the Waitaki River, on the east coast of New Zealand's South Island, was built by Pleistocene glacial advances but has been eroded back by waves over recent millennia. The retreat has left a cliffed shore fronted by a narrow beach of mixed sand and gravel and a gently sloping seabed with only a thin, patchy sand cover over the Pleistocene substrate. The study motivation is to examine the sensitivity of shoreline movements in this setting to wave-climate change, sea-level rise, and river sediment supplies. The modelling couples a profile evolution model with a shoreline model. The profile evolution model is operational and is driven by a series of coupled process models which include seabed scour, berm construction during normal waves, berm overtopping and subsequent beach-stripping and scour of the exposed substrate and cliff-toe notching by storm waves, gravity failure of the cliffs and talus construction, and beach sediment abrasion. Negative feedback regulates the rate of cliff erosion through the protection provided by the new material added into the beach from the eroding cliffs and substrate. The model is forced by two wave conditions: a normal swell and a randomly-varying storm wave. These operate for proportions of the yearly time step. The model was begun on a sloping fan surface inundated by the last stages of post-glacial sea-level rise (8000 yr BP). The initial response is for rapid growth of a gravel beach ridge fed by wave-excavation of the nearshore. As the nearshore profile nears equilibrium with the wave climate, the onshore feed wanes below the abrasion rate and the beach ridge loses volume. As sea level rises the beach ridge moves upward and landward, but its capacity to do so is limited by the rate of sediment feed from the nearshore. When the beach size reduces to a threshold at which storm waves periodically

  18. Biogeochemistry at a wetland sediment-alluvial aquifer interface in a landfill leachate plume (United States)

    Lorah, M.M.; Cozzarelli, I.M.; Böhlke, J.K.


    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

  19. Spatial distribution of triazine residues in a shallow alluvial aquifer linked to groundwater residence time. (United States)

    Sassine, Lara; Le Gal La Salle, Corinne; Khaska, Mahmoud; Verdoux, Patrick; Meffre, Patrick; Benfodda, Zohra; Roig, Benoît


    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

  20. New Module to Simulate Groundwater-Surface Water Interactions in Small-Scale Alluvial Aquifer System. (United States)

    Flores, L.


    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. Mapping groundwater renewability using age data in the Baiyang alluvial fan, NW China (United States)

    Huang, Tianming; Pang, Zhonghe; Li, Jie; Xiang, Yong; Zhao, Zhijiang


    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.

  2. Plucking in Mixed Alluvial-Bedrock Rivers: The Incipient Motion Problem (United States)

    Hurst, A. A.; Furbish, D. J.


    Bedrock river channel erosion is an important factor in the evolution of landscapes, driving the relief of mountainous drainage basins and setting the lowest erosional positions of terrestrial landscapes. The mechanics behind erosional processes (predominantly plucking and abrasion) in these rivers are only recently being explored in depth. Plucking, the fracture and extraction of jointed blocks, is observationally an order of magnitude more efficient than abrasion, but if a river cannot provide the force necessary to move the plucked block, erosion by plucking cannot proceed. Therefore, incipient motion of blocks starting at rest on a solid surface is an important factor in erosion by plucking. Calculations of forces necessary for incipient motion require values of drag coefficients, which do not exist for bedrock contact geometry. We discovered from experiments on a flume that drag coefficients (CD) are inversely proportional to aspect ratios (RA), defined as the frontal block height to width. We used the relationship with field data from plucked blocks at a stream at Montgomery Bell State Park in Burns, TN, a mixed-alluvial bedrock channel with an actively incising knick zone, to support our theory and experimental data. Sizes of plucked blocks were compared to the velocities needed to move them, and then calculations done for bankfull velocities at the stream at Montgomery Bell to determine if it could attain these velocities. It was discovered that this stream has a bankfull depth-averaged velocity of 1.26 m s-1 and is capable of moving a large range of plucked block sizes. Therefore, erosion of this particular stream is plucking-limited, not transport-limited.

  3. Changes in floodplain inundation under nonstationary hydrology for an adjustable, alluvial river channel (United States)

    Call, B. C.; Belmont, P.; Schmidt, J. C.; Wilcock, P. R.


    Predicting the frequency and aerial extent of flooding in river valleys is essential for infrastructure design, environmental management, and risk assessment. Conventional flood prediction relies on assumptions of stationary flood distributions and static channel geometries. However, nonstationary flow regimes are increasingly observed and changes in flow and/or sediment supply are known to alter the geometry and flood conveyance of alluvial channels. Systematic changes in flows and/or channel geometry may amplify or attenuate the frequency and/or extent of flood inundation in unexpected ways. We present a stochastic, reduced complexity model to investigate such dynamics. The model routes a series of annual peak discharges through a simplified reach-averaged channel-floodplain cross section. Channel width, depth, and slope are permitted to adjust annually by a user-specified fraction toward equilibrium geometries predicted based on each year's peak discharge and sediment supply. Modeled channel adjustments are compared with empirical observations for two rivers in Minnesota, USA that have experienced multiple large floods over the past 6 years. The model is then run using six hypothetical scenarios simulating nonstationary flow regimes with temporal adjustments in the mean and/or variance of the governing peak-flow distributions. Each scenario is run repeatedly while varying parameters that control the amount of fractional adjustment that channel geometries can make annually. Results indicate that the intra-annual mean horizontal width of floodplain inundation primarily depends on the governing peak-flow distribution's coefficient of variation, but the intra-annual frequency of floodplain inundation (i.e., the fraction of modeled years with inundation) primarily depends on the amount of channel adjustment permitted annually.

  4. Advances in Field Deployable Instrumented Particles for the Study of Alluvial Transport Mechanisms (United States)

    Dillon, B.; Strom, K.


    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

  5. 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


    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

  6. 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.


    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

  7. Breeding birds in managed forests on public conservation lands in the Mississippi Alluvial Valley (United States)

    Twedt, Daniel J.; Wilson, R. Randy


    Managers of public conservation lands in the Mississippi Alluvial Valley have implemented forest management strategies to improve bottomland hardwood habitat for target wildlife species. Through implementation of various silvicultural practices, forest managers have sought to attain forest structural conditions (e.g., canopy cover, basal area, etc.) within values postulated to benefit wildlife. We evaluated data from point count surveys of breeding birds on 180 silviculturally treated stands (1049 counts) that ranged from 1 to 20 years post-treatment and 134 control stands (676 counts) that had not been harvested for >20 years. Birds detected during 10-min counts were recorded within four distance classes and three time intervals. Avian diversity was greater on treated stands than on unharvested stands. Of 42 commonly detected species, six species including Prothonotary Warbler (Prothonotaria citrea) and Acadian Flycatcher (Empidonax virescens) were indicative of control stands. Similarly, six species including Indigo Bunting (Passerina cyanea) and Yellow-breasted Chat (Icteria virens) were indicative of treated stands. Using a removal model to assess probability of detection, we evaluated occupancy of bottomland forests at two spatial scales (stands and points within occupied stands). Wildlife-forestry treatment improved predictive models of species occupancy for 18 species. We found years post treatment (range = 1–20), total basal area, and overstory canopy were important species-specific predictors of occupancy, whereas variability in basal area was not. In addition, we used a removal model to estimate species-specific probability of availability for detection, and a distance model to estimate effective detection radius. We used these two estimated parameters to derive species densities and 95% confidence intervals for treated and unharvested stands. Avian densities differed between treated and control stands for 16 species, but only Common Yellowthroat

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

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent


    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.

  9. Habitat disturbance and hydrological parameters determine the body size and reproductive strategy of alluvial ground beetles. (United States)

    Gerisch, Michael


    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.

  10. Colluvial and alluvial response to land use change in Midland England: An integrated geoarchaeological approach (United States)

    Brown, Antony G.


    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.

  11. Transport-related mylonitic ductile deformation and shape change of alluvial gold, southern New Zealand (United States)

    Kerr, Gemma; Falconer, Donna; Reith, Frank; Craw, Dave


    Gold is a malleable metal, and detrital gold particles deform via internal distortion. The shapes of gold particles are commonly used to estimate transport distances from sources, but the mechanisms of internal gold deformation leading to shape changes are poorly understood because of subsequent recrystallisation of the gold in situ in placer deposits, which creates a rim zone around the particles, with undeformed > 10 μm grains. This paper describes samples from southern New Zealand in which grain size reduction (to submicrometer scale) and mylonitic textures have resulted from internal ductile deformation. These textures have been preserved without subsequent recrystallisation after deposition in late Pleistocene-Holocene alluvial fan placers. These mylonitic textures were imposed by transport-related deformation on recrystallised rims that were derived from previous stages of fluvial transportation and deposition. This latest stage of fluvial transport and deformation has produced numerous elongated gold smears that are typically 100 μm long and 10-20 μm wide. These smears are the principal agents for transport-induced changes in particle shape in the studied placers. Focused ion beam (FIB) sectioning through these deformed zones combined with scanning electron microscopic (SEM) imaging show that the interior of the gold particles has undergone grain size reduction (to 500 nm) and extensive folding with development of a ductile deformation fabric that resembles textures typical of mylonites in silicate rocks. Relict pods of the pre-existing recrystallised rim zone are floating in this ductile deformation zone and these pods are irregular in shape and discontinuous in three dimensions. Micrometer scale biologically-mediated deposition from groundwater of overgrowth gold on particle surfaces occurs at all stages of placer formation, and some of this overgrowth gold has been incorporated into deformation zones. These examples provide a rare view into the nature

  12. Genotoxicity assessments of alluvial soil irrigated with wastewater from a pesticide manufacturing industry. (United States)

    Anjum, Reshma; Krakat, Niclas


    In this study, organochlorine pesticides (OCP) and heavy metals were analyzed from wastewater- and groundwater- irrigated soils (control samples) by gas chromatography (GC) and atomic absorption spectrophotometry (AAS), respectively. Gas chromatographic analysis revealed the presence of high concentration of pesticides in soil irrigated with wastewater (WWS). These concentrations were far above the maximum residue permissible limits indicating that alluvial soils have high binding capacity of OCP. AAS analyses revealed higher concentration of heavy metals in WWS as compared to groundwater (GWS). Also, the DNA repair (SOS)-defective Escherichia coli K-12 mutant assay and the bacteriophage lambda system were employed to estimate the genotoxicity of soils. Therefore, soil samples were extracted by hexane, acetonitrile, methanol, chloroform, and acetone. Both bioassays revealed that hexane-extracted soils from WWS were most genotoxic. A maximum survival of 15.2% and decline of colony-forming units (CFUs) was observed in polA mutants of DNA repair-defective E. coli K-12 strains when hexane was used as solvent. However, the damage of polA (-) mutants triggered by acetonitrile, methanol, chloroform, and acetone extracts was 80.0, 69.8, 65.0, and 60.7%, respectively. These results were also confirmed by the bacteriophage λ test system as hexane extracts of WWS exhibited a maximum decline of plaque-forming units for lexA mutants of E. coli K-12 pointing to an elevated genotoxic potential. The lowest survival was observed for lexA (12%) treated with hexane extracts while the percentage of survival was 25, 49.2, 55, and 78% with acetonitrile, methanol, chloroform, and acetone, respectively, after 6 h of treatment. Thus, our results suggest that agricultural soils irrigated with wastewater from pesticide industries have a notably high genotoxic potential.


    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


    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.

  14. Water availability and use pilot; methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona (United States)

    Tillman, Fred D.; Cordova, Jeffrey T.; Leake, Stanley A.; Thomas, Blakemore E.; Callegary, James B.


    Executive Summary: Arizona is located in an arid to semiarid region in the southwestern United States and is one of the fastest growing States in the country. Population in Arizona surpassed 6.5 million people in 2008, an increase of 140 percent since 1980, when the last regional U.S. Geological Survey (USGS) groundwater study was done as part of the Regional Aquifer System Analysis (RASA) program. The alluvial basins of Arizona are part of the Basin and Range Physiographic Province and cover more than 73,000 mi2, 65 percent of the State's total land area. More than 85 percent of the State's population resides within this area, accounting for more than 95 percent of the State's groundwater use. Groundwater supplies in the area are expected to undergo further stress as an increasing population vies with the State's important agricultural sector for access to these limited resources. To provide updated information to stakeholders addressing issues surrounding limited groundwater supplies and projected increases in groundwater use, the USGS Groundwater Resources Program instituted the Southwest Alluvial Basins Groundwater Availability and Use Pilot Program to evaluate the availability of groundwater resources in the alluvial basins of Arizona. The principal products of this evaluation of groundwater resources are updated groundwater budget information for the study area and a proof-of-concept groundwater-flow model incorporating several interconnected groundwater basins. This effort builds on previous research on the assessment and mapping of groundwater conditions in the alluvial basins of Arizona, also supported by the USGS Groundwater Resources Program. Regional Groundwater Budget: The Southwest Alluvial Basins-Regional Aquifer System Analysis (SWAB-RASA) study produced semiquantitative groundwater budgets for each of the alluvial basins in the SWAB-RASA study area. The pilot program documented in this report developed new quantitative estimates of groundwater

  15. Plain packaging of cigarettes: do we have sufficient evidence?

    Directory of Open Access Journals (Sweden)

    Smith CN


    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

  16. Late Quarternary evolution of the northern Hatteras Abyssal Plain

    International Nuclear Information System (INIS)

    Dickson, S.M.; Laine, E.P.


    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

  17. Seasonal Mineralogy and Biogeochemistry of an Arid-lands Hyporheic Corridor Along the Alluvial Rio Grande, New Mexico, USA (United States)

    Vinson, D. S.; Pershall, A. D.; Spilde, M. N.; Block, S. E.; Crossey, L. J.; Dahm, C. N.


    The Middle Rio Grande in central New Mexico flows through a semiarid, sand-dominated Quaternary rift basin. Flow regulation measures include dams, irrigation diversions, levees, and bank stabilization. These have caused severe eco-hydrologic impairment including 1) incision, lowered water tables, and the end of overbank flooding; 2) disruption of shallow groundwater cycling; 3) sediment depletion; 4) altered seasonal organic carbon dynamics; and 5) declining native riparian biota. Historically bidirectional flowpaths in the shallow alluvial aquifer (hyporheic corridor) are less reversible due to parallel drainage ditches with lower beds than the river. These ditches impose relatively static hydraulic gradients on the alluvial aquifer and isolate the shallowest groundwater from the agricultural floodplain. Groundwater data along flowpaths and depth profiles indicate seasonally variable biogeochemical cycling, especially metal and sulfate reduction and phreatophyte evapoconcentration. Dissolved Fe is highest in summer and low to undetectable in winter. Both Fe and Mn exhibit substantial spatial variability, indicating the importance of solid-phase interactions. Sulfate reduction is another active terminal electron accepting process, made especially significant by the river's high sulfate concentration, a product of regional geology and semiarid climate. Mn exhibits pervasive down-gradient enrichment unlike Fe, whose mobility along flowpaths is mitigated by a temporary reservoir of sulfide minerals. These processes have been explored further by in situ mineral growth incubations. Scanning electron microscopy/energy-dispersive X-ray spectroscopy has confirmed the importance of redox-sensitive minerals to aquifer biogeochemistry. These phases include Fe-oxyhydroxides and sulfides, both amorphous and apparently crystalline; Mn-oxyhydroxides; and occasional solid phase P. Our research has demonstrated 1) the occurrence of seasonal mineral cycling in this alluvial aquifer

  18. 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


    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

  19. Quality of water in the Red River alluvial aquifer; Pool 1, Red River waterway area, Vick, Louisiana (United States)

    Smoot, C.W.; Seanor, R.C.; Huff, G.F.


    Water-quality changes in the Red River alluvial aquifer within the area affected by pool 1 near Vick, Louisiana, were monitored during pre-construction (1974-78) and post-construction (1984-92) of Lock and Dam 1. Changes greater or less than background values have occurred in an area within 2 miles of Lock and Dam 1, and in one well located about 10 miles west of Lock and Dam 1. Comparison between the pre-construction and post-construction water-quality analyses indicated the total hardness as calcium carbonate and concentrations of dissolved chloride, iron, and manganese generally have decreased in the Red River alluvial aquifer south of the Red River and near Lock and Dam l. The maximum decrease of the median total hardness as calcium carbonate was from 730 to 330 mg/L (milligrams per liter), dissolved chloride from 77 to 46 mg/L, dissolved iron from 18 to 6.9 mg/L, and dissolved manganese from 1.4 to 0.56 mg/L. Analyses of water from wells west of Lock and Dam 1 indicated an increase of the median total hardness as calcium carbonate was from 200 to 260 mg/L, and dissolved iron concentration was from 0.33 to 1.4 mg/L. North of the river and 1 mile west of Lock and Dam l, the median concentration of dissolved chloride increased from 45 to 130 mg/L in water from one well, and median total hardness as calcium cabonate and concentrations of dissolved iron and manganese also increased. Because well Ct-74 is completed in a sand that is in contact with a saltwater sand of Tertiary age, this increase is probably a temporal increase due to upconing after lowering the water level in the alluvial aquifer by pumping of dewatering wells during construction of Lock and Dam 1.

  20. Impact of Irrigated Agroecosystems on Groundwater Resources in the US High Plains and North China Plain (United States)

    Scanlon, B. R.; Longuevergne, L.; Cao, G.; Shen, Y.; Gates, J. B.; Reedy, R. W.; Zheng, C.


    Overabstraction of groundwater for irrigation in semiarid regions is depleting the worlds’ largest aquifers at much greater rates than these aquifers are being replenished by recharge. This study evaluates groundwater sustainability in the US High Plains (US HP) and North China Plain (NCP) where intensive irrigation has resulted in large water table declines. A variety of approaches were used to evaluate impacts of irrigation on groundwater resources, including GRACE satellite data, unsaturated zone profiling, and groundwater quantity and quality data. Cultivation (40% of area) and irrigation (12%) are less intensive in the US HP than in the NCP (80% cultivated, 50% irrigated). Irrigation is estimated to consume ~97% of groundwater resources in the US HP and ~70% in the NCP. Although only ~10% of groundwater resources has been consumed in the US HP (330 km3 out of 3,900 km3), the problem lies in the uneven spatial distribution. Groundwater depletion is greatest in the Central High Plains (CHP) where water table declines of up to 1.5 m/yr have been recorded in individual wells and regional declines of up to 30 m have been found over a 7,000 km2 area since irrigation began in the 1950s to 1960s. This depletion indicates an irrigation deficit of ~75 mm/yr over 60 yr (specific yield 15%). Recharge rates in the CHP are extremely low (median ~10 mm/yr) with reductions in groundwater storage exceeding recharge by ~10 times. High correlations between GRACE and measured water storage changes (R = 0.7 - 0.8) show that the satellite can accurately track regional changes in water storage. Groundwater in the NCP has declined from a depth of ~1 m in the 1960s to 20 to 40 m in the Piedmont region since expansion of irrigation beginning in the 1970s. Groundwater level declines in individual hydrographs range from 0.5 to 1.0 m/yr, indicating irrigation deficits ranging from 100 to 200 mm/yr (specific yield 20%). Lower groundwater storage changes from GRACE satellites relative to

  1. An expert system as a support to the decision making process for groundwater management of alluvial groundwater bodies in Slovenia

    Directory of Open Access Journals (Sweden)

    Petra Souvent


    Full Text Available The expert decision support system for groundwater management in the shallow alluvial aquifers links numerical groundwater flow models with the water permits and concessions databases in order to help groundwater managers to quantify sustainable yield for a given groundwater body and provide additional information for sustainable groundwater management. Stand alone numerical groundwater models are used in the process of the assessment of groundwater quantitative status as well as for assessing local yield quantity during the period of maximum water demand and minimum groundwater recharge.

  2. Hydraulic properties variations response to seismic activity in the thick alluvial materials overlying an active fault: the Chihshang Fault (Taiwan) (United States)

    Mu, C. H.; Lee, J. C.; Cappa, F.; Guglielmi, Y.; Randolph-Flagg, N. G.


    The Chihshang Fault, one of the most active creeping faults in the world at a surface slip rate of 2-3 cm/yr, is located at plate suture between the Philippine Sea and the Eurasian plates in eastern Taiwan. Near the surface at the Chinyuan village, the Chihshang Fault propagates into the Holocene unconsolidated gravel layers. There, the Chihshang Fault displays a three-branch fault system with a diffused fault zone in the Chinyuan alluvial fan, which is composed of at least 100 m thick alluvial deposits. Outside of the Chinyuan fan, the Chihshang Fault exhibits a single fault system. In order to better understand whether the pore-fluid pressure variations within the alluvial gravels influences the near-surface seasonal locked behavior of the Chihshang Fault, we drilled four groundwater wells of depth of 30-100 m across the fault zone in the alluvial fan. Monitoring of natural pore pressure variations in piezometers, monthly slug experiments, and long duration pumping/injection experiments were carried out during 2007-2011. Together with the subsurface electrical resistivity imaging and core geological analysis, we identified a shallow aquifer layer that is deformed and truncated by the obliquely dipping fault zone. The results showed that the permeability within the fault zone is an order of magnitude less than that outside of the fault zone (i.e., the footwall and the hanging wall). This change in permeability may explain the 8-10 meter step of offset in groundwater level across the fault. In addition, repeated slug tests revealed that the permeability not only varied seasonally but also increased gradually by 20 fold in the hanging wall from 2007 to 2011. A dramatic jump in the permeability in the fault zone was observed from April to September 2008. This phenomenon is interpreted as a result of a cluster of low magnitude earthquakes occurred at the shallow crust, which may either have changed the static stress field along the fault, or cause dilatation that

  3. Geologic map of the northern plains of Mars (United States)

    Tanaka, Kenneth L.; Skinner, James A.; Hare, Trent M.


    The northern plains of Mars cover nearly a third of the planet and constitute the planet's broadest region of lowlands. Apparently formed early in Mars' history, the northern lowlands served as a repository both for sediments shed from the adjacent ancient highlands and for volcanic flows and deposits from sources within and near the lowlands. Geomorphic evidence for extensive tectonic deformation and reworking of surface materials through release of volatiles occurs throughout the northern plains. In the polar region, Planum Boreum contains evidence for the accumulation of ice and dust, and surrounding dune fields suggest widespread aeolian transport and erosion. The most recent regional- and global-scale maps describing the geology of the northern plains are largely based on Viking Orbiter image data (Dial, 1984; Witbeck and Underwood, 1984; Scott and Tanaka, 1986; Greeley and Guest, 1987; Tanaka and Scott, 1987; Tanaka and others, 1992a; Rotto and Tanaka, 1995; Crumpler and others, 2001; McGill, 2002). These maps reveal highland, plains, volcanic, and polar units based on morphologic character, albedo, and relative ages using local stratigraphic relations and crater counts. This geologic map of the northern plains is the first published map that covers a significant part of Mars using topography and image data from both the Mars Global Surveyor and Mars Odyssey missions. The new data provide a fresh perspective on the geology of the region that reveals many previously unrecognizable units, features, and temporal relations. In addition, we adapted and instituted terrestrial mapping methods and stratigraphic conventions that we think result in a clearer and more objective map. We focus on mapping with the intent of reconstructing the history of geologic activity within the northern plains, including deposition, volcanism, erosion, tectonism, impact cratering, and other processes with the aid of comprehensive crater-density determinations. Mapped areas include all

  4. Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA (United States)

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.


    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

  5. Food Vulnerability and Alluvial Farming for Food Security in Central Dry Zone Area of Myanmar (United States)

    Boori, M. S.; Choudhary, K.; Evers, M.; Kupriyanov, A.


    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

  6. River path selection in response to uplift and interaction with alluvial fans (United States)

    Grimaud, J. L.; Paola, C.; Voller, V. R.


    River systems construct stratigraphic successions and build land by depositing and redistributing sediments as they migrate across the entire basin. This mobility arises from the intrinsic variability of a river system but can also be forced by external changes. It is particularly observable in tectonically active basins where the basement can be partly uplifted and where sediments can come from multiple sources. Theoretically, the ability of these perturbations to steer channels depends on their capacity to create lateral topographic gradients at a faster rate than the aggradation. Following these lines, we present an experimental study on the impacts of lateral tilting by tectonics and lateral alluvial fans on rivers path. The experiment was conducted in the eXperimental Earth Scape facility, also known as the Jurassic tank, where the basement tilting rate can be monitored by controlling individually gravel subsidence through 108 hexagonal cells. The basin was relatively uplifted on one side of the tank according to an anticline-shape and sediments were input through two sources: a main, axial one and a lateral, secondary one. We analyzed the differences in the topographic signature and flow occupation of rivers in response to the uplift or the lateral sediment source as well as the competition of these forcing in the late stages of the experiments. We found that both tectonic tilting and fan activity tend to decrease the basin-wide channel mobility. Indeed, the area at the convergence of the two interacting fans is a long-lasting topographic low that tends to channelize the flow while areas away from it are less visited. The position of this boundary is correlated with the relative flow contribution from both fans. This highlights the self-healing capacity of fans that are able to rapidly restore a graded shape. As opposed to fans, an uplifted area will not heal but force rivers to carve long-lasting valleys and increase the relief. When eroded, these uplifted

  7. An Apparatus for Bed Material Sediment Extraction From Coarse River Beds in Large Alluvial Rivers (United States)

    Singer, M. B.; Adam, H.; Cooper, J.; Cepello, S.


    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

  8. Unconfined alluvial flow processes: Recognition and interpretation of their deposits, and the significance for palaeogeographic reconstruction (United States)

    North, Colin P.; Davidson, Stephanie K.


    Palaeogeographic interpretation of the sedimentary rock record depends on correct recognition from the preserved evidence of the processes responsible for transporting and depositing the sediment. This in turn depends on robust knowledge transfer from previous workers, and the successful exchange of ideas between workers requires consistent use of a well-defined vocabulary. We have identified serious breakdowns in all these interpretation steps in the case of terrestrial unconfined flow and its deposits, and these failures are leading to unreliable environmental and climatic interpretation. This is significant because such alluvial deposits commonly form a majority of the rock record of continental environments. Working from the basic principles of geomorphology and fluid dynamics, we have undertaken a wide-ranging analysis of the nature of out-of-channel flow and from this make predictions about the characteristics of its deposits. We identify the range of possible locations and conditions that lead to the development of unconfined flow, review the processes operating in each case, and examine the range of lithological features that can be produced by these processes. This allows us to evaluate the reliability of the criteria claimed for identification of out-of-channel flow deposits, and examine how our new insights might alter palaeoclimatic and palaeogeographic reconstructions published previously by others. The sedimentary record of unconfined flows is much more diverse and complex than usually portrayed. The received wisdom that the record of unconfined flow consists solely of upwards-fining thin beds produced from shallow waning flows is shown to be flawed. A wide range of lithofacies are possible, and the variation in both flow steadiness and uniformity needs to be taken into account. The previously published criteria for recognition of flows of this type are not diagnostic of process or location; unconfined flow deposits cannot reliably be identified from

  9. Interactions between fauna and environment in recent alluvial soils (Dunajec River, SE Poland) (United States)

    Mikuś, Paweł; Uchman, Alfred


    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

  10. Alluvial diamond resource potential and production capacity assessment of the Central African Republic (United States)

    Chirico, Peter G.; Barthelemy, Francis; Ngbokoto, Francois A.


    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


    Directory of Open Access Journals (Sweden)

    M. S. Boori


    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

  12. Plains Elevated Convection at Night (PECAN) Experiment Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    Turner, D [National Oceanic and Atmospheric Administration; Parsons, D [NCAR; Geerts, B [Department of Atmospheric Science, University of Wyoming


    The Plains Elevated Convection at Night (PECAN) experiment is a large field campaign that is being supported by the National Science Foundation (NSF) with contributions from the National Oceanic and Atmospheric Administration (NOAA), the National Atmospheric and Space Administration (NASA), and the U.S. Department of Energy (DOE). The overarching goal of the PECAN experiment is to improve the understanding and simulation of the processes that initiate and maintain convection and convective precipitation at night over the central portion of the Great Plains region of the United States (Parsons et al. 2013). These goals are important because (1) a large fraction of the yearly precipitation in the Great Plains comes from nocturnal convection, (2) nocturnal convection in the Great Plains is most often decoupled from the ground and, thus, is forced by other phenomena aloft (e.g., propagating bores, frontal boundaries, low-level jets [LLJ], etc.), (3) there is a relative lack of understanding how these disturbances initiate and maintain nocturnal convection, and (4) this lack of understanding greatly hampers the ability of numerical weather and climate models to simulate nocturnal convection well. This leads to significant uncertainties in predicting the onset, location, frequency, and intensity of convective cloud systems and associated weather hazards over the Great Plains.

  13. General practitioners' willingness to request plain lumbar spine radiographic examinations

    International Nuclear Information System (INIS)

    Ryynaenen, Olli-Pekka; Lehtovirta, Jukka; Soimakallio, Seppo; Takala, Jorma


    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

  14. Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania. (United States)

    Miller, Kirk; Yost, Berwood; Abbott, Christina; Thompson, Scottie; Dlugi, Emily; Adams, Zachary; Schulman, Meryl; Strauss, Nicole


    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.

  15. Quaternary evolution of the Southern Apennines coastal plains: a review

    Directory of Open Access Journals (Sweden)

    Santangelo Nicoletta


    Full Text Available The Quaternary evolution of the main coastal basins located along the southwestern margin of the Southern Apennines has been reconstructed by integrating the huge amount of existing stratigraphical and geomorphological data. The information produced in the last twenty years has shed new light on the recent (late Middle Pleistocene to Present history of the Campanian and Sele plains or basins. During the early Quaternary, the analysed coastal basins originated as half-grabens in response to opening processes active since the late Tortonian in the southern Tyrrhenian back-arc basin. In some of these basins (e.g. the Campanian Plain, volcanism has also played an important role. In the inner sectors of the coastal basins, the complex interplay between block faulting, sedimentary inputs and glacioeustatic fluctuations gave rise to relative sea-level change and related coastline migrations, leading to the formation of the present-day coastal plains. In the Sele Plain basin, the construction of the present-day landscape mainly resulted from the substantial ceasing of subsidence in the final part of the Middle Pleistocene. Conversely, a strong contribution to the recent evolution of the Campanian Plain has been provided by abundant volcaniclastic aggradation, able to hinder the effect of the vertical motions that occurred in the last 100 ka.

  16. Older Smooth Plains on Mercury Obscured by Impact Features (United States)

    Byrne, P. K.; Denevi, B. W.; Klimczak, C.; Prockter, L. M.; Solomon, S. C.; Whitten, J.; Head, J. W.


    On the basis of morphology and spectral reflectance, the surface of Mercury can be broadly divided into three major terrain types: low-reflectance material, intermediate terrain, and smooth plains. This last terrain type is distinguished morphologically by a comparatively smooth and gently rolling surface, has a lower density of impact craters and basins than other surface units on the planet, and typically occupies low-lying areas. Their smooth texture, embayment of other landforms, and distinctive partial to complete burial of older impact features suggests that most of these plains are probably volcanic in nature. Recent mapping work has shown that smooth plains younger than the end of the late heavy bombardment (LHB) occupy ~30% of Mercury's surface. An outstanding question concerns the distribution and nature of older plains units on the planet, especially those that underlie large impact features and may correspond morphologically to smooth plains but have not yet been mapped accordingly. A preliminary survey of such terrain yielded five exemplar sites: at the Amaral (26.5°S, 117.8°E; 101 km diameter), Mickiewicz (23.2°N, 256.7°E; 103 km), and Vivaldi (13.8°N, 274.1°E; 212 km) basins and at two unnamed features at 53.1°S, 38.6°E (83 km in diameter) and 7.1°N, 38.3°E (118 km). We expect that more thorough mapping will uncover additional candidate areas. In each of the example sites, an extensive continuous ejecta deposit and secondary impact field characterize the proximal and distal facies, respectively, of the impact feature; and in each case, the secondaries field (and impact-sculpted terrain in the case of Vivaldi) is superposed upon patches of plains that otherwise appear smooth and host numerous, flooded antecedent craters tens of kilometers in diameter. Moreover, these smooth patches occur at several ranges of azimuths surrounding each crater or basin, suggesting that they may have formed contiguous units prior to formation of the younger

  17. Attack on Australia: tobacco industry challenges to plain packaging. (United States)

    Jarman, Holly


    In 2011, the Australian Government passed landmark legislation requiring tobacco manufacturers to adopt 'plain packaging', a government-mandated design standardized across all brands of tobacco products. In response, plain packaging policy in Australia has faced multiple, simultaneous challenges from a global, well-resourced industry able to use all available fora to seek redress. Generalizing from the Australian experience, we analyze four types of challenges to plain packaging from the tobacco industry. We characterize three ways in which industry questions public health policies through international trade and investment law, on: (i) the intent or purpose of the policy; (ii) the economic consequences of it; and (iii) the regulatory authority behind it. We make recommendations and suggest that public health policymakers can know with some precision what attacks will be launched on tobacco control policies, and prepare their strategies and legislation accordingly.

  18. Tobacco branding, plain packaging, pictorial warnings, and symbolic consumption. (United States)

    Hoek, Janet; Gendall, Philip; Gifford, Heather; Pirikahu, Gill; McCool, Judith; Pene, Gina; Edwards, Richard; Thomson, George


    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.

  19. Risks associated with rainfall and floods in the Moldavian Plain

    Directory of Open Access Journals (Sweden)



    Full Text Available Climate changes, less effective land exploitation and insufficient security infrastructure against extreme phenomena induce vulnerabilities for the Moldavian Plain, where floods are relatively frequent. The middle and lower segments of the major streams dispose of improved hydro-technical infrastructure to prevent floods, still, the secondary streams and tributaries, with pronounced torrential characterremain vulnerable. The torrential character of the majority of rivers inthe Moldavian Plain results in management difficulties related with risksat maximum flow, especially on the first rank tributaries. Our studyanalyzes the main causes and consequences of floods in the MoldavianPlain and identifies potentially significant flood risks areas.

  20. Diamonds from the Machado River alluvial deposit, Rondônia, Brazil, derived from both lithospheric and sublithospheric mantle (United States)

    Burnham, A. D.; Bulanova, G. P.; Smith, C. B.; Whitehead, S. C.; Kohn, S. C.; Gobbo, L.; Walter, M. J.


    Diamonds from the Machado River alluvial deposit have been characterised on the basis of external morphology, internal textures, carbon isotopic composition, nitrogen concentration and aggregation state and mineral inclusion chemistry. Variations in morphology and features of abrasion suggest some diamonds have been derived directly from local kimberlites, whereas others have been through extensive sedimentary recycling. On the basis of mineral inclusion compositions, both lithospheric and sublithospheric diamonds are present at the deposit. The lithospheric diamonds have clear layer-by-layer octahedral and/or cuboid internal growth zonation, contain measurable nitrogen and indicate a heterogeneous lithospheric mantle beneath the region. The sublithospheric diamonds show a lack of regular sharp zonation, do not contain detectable nitrogen, are isotopically heavy (δ13CPDB predominantly - 0.7 to - 5.5) and contain inclusions of ferropericlase, former bridgmanite, majoritic garnet and former CaSiO3-perovskite. This suggests source lithologies that are Mg- and Ca-rich, probably including carbonates and serpentinites, subducted to lower mantle depths. The studied suite of sublithospheric diamonds has many similarities to the alluvial diamonds from Kankan, Guinea, but has more extreme variations in mineral inclusion chemistry. Of all superdeep diamond suites yet discovered, Machado River represents an end-member in terms of either the compositional range of materials being subducted to Transition Zone and lower mantle or the process by which materials are transferred from the subducted slab to the diamond-forming region.

  1. Spatial-temporal variation in the dynamics of the tree community in fragments of alluvial forest in Minas Gerais

    Directory of Open Access Journals (Sweden)

    Ana Carolina da Silva


    Full Text Available This study explored the dynamics pattern of the tree community in fragments of alluvial forest in the period 2005-2007 and in the period 2007-2009. The study comprises a fragment of riparian forest and five fragments of alluvial forest toward the interior of the floodplain of Sapucaí river, in São Sebastião da Bela Vista, MG, initially inventoried in 2005 and then evaluated in 2007 and again in 2009. Results revealed different patterns among fragments and among time intervals. In the fragments where in previous studies a stronger influence of floods and sodden soil had been observed, tree mortality was found to be greater in the 2007-2009 period than in the 2005-2007 period. Overall, mortality rates were found to be higher than recruitment rates, leading to loss of individuals and loss of basal area. Judging by the history of the area, it can be assumed that these losses are due to an interaction of two factors: i water excess after major flooding and ii occurrence of strong anthropization, represented by selective logging and cattle introduction in the interior of the fragments.

  2. Comparison of groundwater recharge estimation techniques in an alluvial aquifer system with an intermittent/ephemeral stream (Queensland, Australia) (United States)

    King, Adam C.; Raiber, Matthias; Cox, Malcolm E.; Cendón, Dioni I.


    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.

  3. 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


    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

  4. 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


    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

  5. Investigations on alluvial deposits through borehole stratigraphy, radiocarbon dating and passive seismic technique (Carnic Alps, NE Italy) (United States)

    Viero, Alessia; Marchi, Lorenzo; Cavalli, Marco; Crema, Stefano; Fontana, Alessandro; Mozzi, Paolo; Venturini, Corrado


    Alluvial sediment investigations provide fundamental tools to infer the processes that control geomorphological evolution of mountain environments. By analyzing sediment stratigraphy in depth, it is possible to retrieve the source, the geology, the time of deposition, the relative distance travelled by material as well as to distinguish among different type of transport (i.e., gravitational, fluvial or glacial). In this work, we present a combination of log stratigraphy, radiocarbon dating and geophysical surveys carried out on the valley floor of the But River (Carnic Alps, North East Italy). The But River basin drains an area of 326 km2 with a range in elevation from 2769 to 323 m a.s.l.; the bedrock mainly consists of carbonates and quartz arenites with minor inclusions of effusive rocks. After Pleistocene the gravitational deposits from mountain slopes have impounded the But River several times. In particular, we analyzed a sector of the upper portion of the But valley close to the confluence of the Moscardo Torrent, frequently affected by debris flows. A borehole was drilled in the But River floodplain, at the intersection with the Moscardo Torrent alluvial fan, down to a depth of 80 m. The analysis of the core samples allowed discerning three sedimentary levels rich in clay and organic materials, which testify the presence of small dam lakes, originated from the Moscardo debris-flow deposits. Three samples of wood and plant debris were collected from 13, 14 and 23 m of depth, respectively. They were analyzed through radiocarbon dating in order to determine the age of the lakes and, thus, to infer the activity of the debris flows building the Moscardo cone. The calibrated ages of the 3 samples are close to the younger limit of the radiocarbon method indicating a fast aggradation of the valley floor, starting from a period ranging between 1450 - 1632 AD. Historical maps and documents confirm the presence of the lakes until 19th century and they permit to assess

  6. Morphodynamics of semi-alluvial streams in northern Fennoscandia: a flume experiment to determine bedform self-organization (United States)

    Polvi, Lina


    Streams in northern Fennoscandia have two characteristics that complicate a process-based understanding of sediment transport affecting channel form: (1) they are typically semi-alluvial, in that they contain coarse glacial legacy sediment, and (2) numerous mainstem lakes buffer sediment and water fluxes. Systematic studies of these streams are complicated because natural reference sites are lacking due to over a century of widespread channel simplification to aid timber-floating. This research is part of a larger project to determine controls on channel geometry and sediment transport at: (1) the catchment scale, examining downstream hydraulic geometry, (2) the reach scale, examining sediment transport, and (3) the bedform scale, examining the potential for predictable bedform formation. The objective of the current study, targeting the bedform scale, was to use a flume experiment to determine whether sediment self-organizes and creates bedforms in semi-alluvial channels. The prototype channels, tributaries to the unregulated Vindel River in northern Sweden that are being restored after timber-floating, contain coarse sediment (D16: 55 mm, D50:250 mm, D84:620 mm) with moderately steep slopes (2-5%) and typically experience snowmelt-flooding and flooding due to ice jams. Using a scaling factor of 8 for Froude number similitude, an 8-m long, 1.1 m wide fixed-bed flume was set up at the Colorado State University Engineering Research Center with a scaled-down sediment distribution analogous to the prototype channels. For two flume setups, with bed slopes of 2% and 5%, four runs were conducted with flows analogous to QBF, Q2, Q10 and Q50 flows in the prototype channels until equilibrium conditions were reached. Digital elevation models (DEMs) of bed topography were constructed before and after each run using structure-from-motion photogrammetry. To examine self-organization of sediment, DEMs of difference between pre-flow conditions and after each flow were created

  7. Plain and Rolled Images from Paired Fingerprint Cards (United States)

    NIST Plain and Rolled Images from Paired Fingerprint Cards (Web, free access)   NIST Special Database 29 is being distributed for use in development and testing fingerprint matching systems. The data consist of 216 ten-print fingerprint card pairs with both the rolled and plains (from a bottom of the fingerprint card) scanned at 19.7 pixels per mm. A newer version of the compression/decompression software on the CDROM can be found at the website as part of the NBIS package.

  8. Geoarchaeologic and paleopedologic evidences for the holocene paleoenvironmental evolution of the Crisuri plain (Western Romania

    Directory of Open Access Journals (Sweden)

    Nicolae Josan


    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

  9. 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 (United States)

    Ryter, Derek W.; Correll, Jessica S.


    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.

  10. The role of the uncertainty in assessing future scenarios of water shortage in alluvial aquifers (United States)

    Romano, Emanuele; Camici, Stefania; Brocca, Luca; Moramarco, Tommaso; Guyennon, Nicolas; Preziosi, Elisabetta


    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

  11. Nutrient fluxes in litterfall of a secondary successional alluvial rain forest in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Maurício Bergamini Scheer


    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

  12. Depletion of rice as food of waterfowl wintering in the Mississippi Alluvial Valley (United States)

    Greer, Danielle M.; Dugger, Bruce D.; Reinecke, Kenneth J.; Petrie, Mark J.


    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

  13. 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


    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

  14. 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.

  15. Removal of nanoparticles from plain and patterned surfaces using nanobubbles

    NARCIS (Netherlands)

    Yang, S.; Duisterwinkel, A.E.


    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

  16. Long-term Agroecosystem Research in the Northern Great Plains. (United States)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.


    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.

  17. 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...

  18. 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 ...

  19. Visualizing Gender Variability in Plains Indian Pictographic Art (United States)

    Carocci, Max


    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…

  20. Traditional Plains Indian Art and the Contemporary Indian Student. (United States)

    Pakes, Fraser


    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…

  1. Inclusivity, Gestalt principles, and plain language in document design.


    Farrell, Helen


    Blog post introducing Turner & Schomberg's (2016) paper on inclusive practices in document design, using Gestalt components to illustrate the process of writing and designing material, in order to foster online discussion in the Information Literacy Journal Club. Turner, J. and Schomberg, J. (2016) ‘Inclusivity, Gestalt principles, and plain language in document design’, In the Library with the Lead Pipe.

  2. Research on Fish Consumer Profile Evaluation in Romanian Plain Area


    Silvius STANCIU; Costel NISTOR; Loredana DUMITRASCU; Nicoleta STANCIUC; Isabelle METAXA


    Research aimed at shaping a fish consumer profile in the Romanian Plain area. 150 people were interviewed. Preferences evaluation was conducted by means of a questionnaire with 27 questions. Favorite fish species, purchasing place and manner, favorite preparation choices, consumption frequency and place have been identified.

  3. Research on Fish Consumer Profile Evaluation in Romanian Plain Area

    Directory of Open Access Journals (Sweden)

    Silvius STANCIU


    Full Text Available Research aimed at shaping a fish consumer profile in the Romanian Plain area. 150 people were interviewed. Preferences evaluation was conducted by means of a questionnaire with 27 questions. Favorite fish species, purchasing place and manner, favorite preparation choices, consumption frequency and place have been identified.

  4. Wintering Golden Eagles on the coastal plain of South Carolina (United States)

    Mark Vukovich; K.L. Turner; T.E. Grazia; T. Mims; J.C. Beasley; John Kilgo


    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S...

  5. Introducing Plain Language Principles to Business Communication Students (United States)

    Greer, Rachelle R.


    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…

  6. Fatigue crack growth due to overloads in plain concrete using ...

    Indian Academy of Sciences (India)

    The proposed model is able to capture size effect appropriately which is an important aspect in fracture mechanics study of concrete structures. Further, in another study by the same authors, Ray & Chandra Kishen (2010), they have employed the population growth model to study the fatigue crack propagation in plain ...

  7. Acanthosis Nigricans among Northern Plains American Indian Children (United States)

    Brown, Blakely; Noonan, Curtis; Bentley, Bonnie; Conway, Kathrene; Corcoran, Mary; FourStar, Kris; Gress, Shannon; Wagner, Sharon


    The purpose of this study is to present cross-sectional and prospective data on acanthosis nigricans (AN) prevalence in the context of other risk factors for diabetes including high body mass index (BMI), abnormal blood pressure (BP), physical inactivity and family history of diabetes among Northern Plains American Indian (AI) children.…

  8. 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; Kalb, Juan; Hemmingsson, Peter; Pinheiro, Miguel; Davenport, James; Guidi, Pier Luigi; Simoes da Silva, Ana Paula; Martinho, Goncalo; Spennacchio, Pietro; Postnov, Yury; Dreiangel, Niv; Junior, Nelson Gomes; Frangez, Igor; Bissell, Iain; Khan, Yasir; Toom, Alar; Bergen, Christiaan van; Liszka, Henryk; Moreno, Nestor; Patczai, Balázs; van den Bogaert, Max; Marquis, Christopher; Hussein, Amro Kamal; Andersen, Mette; Botezatu, Lozefina; Santos, Francisco Flores; Nery, Caio; Becirbegovc, Semin; Stoffel, Cristhopher Lucca; Ferrao, Paulo; Rakovac, Ivan; Darabos, Nikica; Sicchiero, Paolo; Tengiz, Kostava; Keiserman, Luciano; Yeap, Ewe Juan; Rocha de Souza, Andrè Luiz; Abdulsalam, Samir; Ramos, Acacio; Martinelli, Nicolú; Verfaillie, Stefaan; Silva, Carmen; Stufkens, Sjoerd; Chouliaras, Vasileios; da Costa, Daniel; Freihaut, Richard; Bulstra, Gythe; Burg, Alon; Rudge, Ben; Abdelwahab, Ali; Sirio, Adrian; Watson, Troy; Gaspar, Ana Rita; Sharp, Ian; Hossain, Munier; van Deurzen, Derek; van den Bekerom, Michel; Wiegerinck, Jan-Joost; van Eekeren, Inge; de Muinck Keizer, Robert-Jan


    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

  9. Wintering Golden Eagles on the coastal plain of South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Vukovich, Mark [USDA Forest Service-Savannah River, New Ellenton, SC (United States); Turner, Kelsey L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Univ. of Georgia, Aiken, SC (United States); Grazia, Tracy E. [USDA Forest Service, New Ellenton, SC (United States). Savannah River; Mims, Thiomas [USDA Forest Service, New Ellenton, SC (United States). Savannah River; Beasley, James C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Univ. of Georgia, Aiken, SC (United States); Kilgo, John C. [USDA Forest Service-Savannah River, New Ellenton, SC (United States)


    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S. Department of Energy’s Savannah River Site on the coastal plain of South Carolina. We identified eight individual Golden Eagles during the winters of 2013–2014 and 2014–2015, with one detected during both winters. We detected eagles for 19 and 66 calendar days during the winters of 2013–2014 and 2014–2015, respectively, with two adult eagles detected for 30 and 31 calendar days in 2014–2015. Eagles typically scavenged on carcasses for a few days, left, and then returned when cameras were baited with another carcass, suggesting they had remained in the area. These observations suggest that large tracts of forests on the coastal plain may be important wintering areas for some Golden Eagles and, further, that other areas in the coastal plain of the southeastern United States may also harbor wintering eagles. Identification of wintering areas of Golden Eagles in the east will be an important step in the conservation of this protected species, and camera traps baited with carcasses can be an effective tool for such work.

  10. Wind Shear Characteristics at Central Plains Tall Towers (presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.; Elliott, D.


    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.

  11. 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 ...

  12. Flour Flame Thrower: The "Flaming Potential" of Plain Flour (United States)

    Sandoval, Christopher


    Plain flour has a lot of chemical energy packed into it. When the flour is in a clump or pile it does not ignite although it may blacken. This is because there is not enough flour exposed to the oxygen in the air. Aerosolising the flour exposes it to much more oxygen allowing a self sustaining combustion reaction to occur when an ignition source…

  13. Radiopaque intrahepatic duct stones in plain radiograph: case report

    International Nuclear Information System (INIS)

    Kim, Mi Young; Suh, Chang Hae; Park, Chan Sup; Chung, Won Kyun


    We experienced 3 cases of intrahepatic duct stones detected on plain radiographs. The patients had history of multiple episodes of recurrent cholangitis. Radiographic characteristics of these stones included multiple, round or rectangular radiopaque densities surrounded by calcified rim; these densities showed a branching pattern along the intrahepatic ducts

  14. Destruction of the arid plains by tubing in Kalmykia

    Directory of Open Access Journals (Sweden)

    V. P. Chichagov


    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.

  15. 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 ...

  16. A Plain English Map of the Human Glycolysis Enzymes. (United States)

    Offner, Susan


    Presents a plain English map of the gene coding for the glycolysis enzymes in humans to be used as a teaching tool. The map can be used to illustrate that every reaction in a cell requires an enzyme, and that every enzyme is a protein coded for by a gene somewhere on the chromosomes. (WRM)

  17. Plain strain problem of poroelasticity using eigenvalue approach

    Indian Academy of Sciences (India)

    A plain strain problem of an isotropic elastic liquid-saturated porous medium in poroelasticity has been studied. The eigenvalue approach using the Laplace and Fourier transforms has been employed and these transforms have been inverted by using a numerical technique. An application of infinite space with ...

  18. Forest statistics for the Coastal Plain of Virginia, 1976 (United States)

    Noel D. Cost


    This report highlights the principal findings of the fourth inventory of the timber resource in the coastal Plain of Virginia. The inventory was started in February 1975 and completed in November 1975. Three previous inventories, completed in 1940, 1956, and 1966, provide statistics for measuring changes and trends over the past 36 years. In this report, the primary...

  19. Forest statistics for the Coastal Plain of Virginia, 1991 (United States)

    Michael T. Thompson


    This report highlights the principal findings of the sixth forest survey of the Coastal Plain of Virginia. Field work began in October 1990 and was completed in March 1991. Five previous surveys, completed in 1940, 1956, 1966, 1976, and 1985, provide statistics for measuring changes and trends over the past 51 years. The primary emphasis in this report is on the...

  20. Forest statistics for the Coastal Plain of Virginia, 1985 (United States)

    Mark J. Brown; Gerald C. Craver


    This report highlights the principal findings of the fifth forest survey in the Coastal Plain of Virginia. Fieldwork began in September 1984 and was completed in February 1985. Four previous surveys, completed in 1940, 1956, 1966, and 1976, provide statistics for measuring changes and trends over the past 45 years. The primary emphasis in this report is on the changes...


    African Journals Online (AJOL)


    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 ...


    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Wahid


    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.

  3. 78 FR 17653 - Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408) (United States)


    ... 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

  4. Sources, lability and solubility of Pb in alluvial soils of the River Trent catchment, U.K. (United States)

    Izquierdo, M; Tye, A M; Chenery, S R


    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

  5. An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field mapping, and remote sensing (United States)

    Pelletier, J.D.; Mayer, L.; Pearthree, P.A.; House, P.K.; Demsey, K.A.; Klawon, J.K.; Vincent, K.R.


    Millions of people in the western United States live near the dynamic, distributary channel networks of alluvial fans where flood behavior is complex and poorly constrained. Here we test a new comprehensive approach to alluvial-fan flood hazard assessment that uses four complementary methods: two-dimensional raster-based hydraulic modeling, satellite-image change detection, fieldbased mapping of recent flood inundation, and surficial geologic mapping. Each of these methods provides spatial detail lacking in the standard method and each provides critical information for a comprehensive assessment. Our numerical model simultaneously solves the continuity equation and Manning's equation (Chow, 1959) using an implicit numerical method. It provides a robust numerical tool for predicting flood flows using the large, high-resolution Digital Elevation Models (DEMs) necessary to resolve the numerous small channels on the typical alluvial fan. Inundation extents and flow depths of historic floods can be reconstructed with the numerical model and validated against field- and satellite-based flood maps. A probabilistic flood hazard map can also be constructed by modeling multiple flood events with a range of specified discharges. This map can be used in conjunction with a surficial geologic map to further refine floodplain delineation on fans. To test the accuracy of the numerical model, we compared model predictions of flood inundation and flow depths against field- and satellite-based flood maps for two recent extreme events on the southern Tortolita and Harquahala piedmonts in Arizona. Model predictions match the field- and satellite-based maps closely. Probabilistic flood hazard maps based on the 10 yr, 100 yr, and maximum floods were also constructed for the study areas using stream gage records and paleoflood deposits. The resulting maps predict spatially complex flood hazards that strongly reflect small-scale topography and are consistent with surficial geology. In

  6. Object-based delineation and classification of alluvial fans by application of mean-shift segmentation and support vector machines (United States)

    Pipaud, Isabel; Lehmkuhl, Frank


    In the field of geomorphology, automated extraction and classification of landforms is one of the most active research areas. Until the late 2000s, this task has primarily been tackled using pixel-based approaches. As these methods consider pixels and pixel neighborhoods as the sole basic entities for analysis, they cannot account for the irregular boundaries of real-world objects. Object-based analysis frameworks emerging from the field of remote sensing have been proposed as an alternative approach, and were successfully applied in case studies falling in the domains of both general and specific geomorphology. In this context, the a-priori selection of scale parameters or bandwidths is crucial for the segmentation result, because inappropriate parametrization will either result in over-segmentation or insufficient segmentation. In this study, we describe a novel supervised method for delineation and classification of alluvial fans, and assess its applicability using a SRTM 1‧‧ DEM scene depicting a section of the north-eastern Mongolian Altai, located in northwest Mongolia. The approach is premised on the application of mean-shift segmentation and the use of a one-class support vector machine (SVM) for classification. To consider variability in terms of alluvial fan dimension and shape, segmentation is performed repeatedly for different weightings of the incorporated morphometric parameters as well as different segmentation bandwidths. The final classification layer is obtained by selecting, for each real-world object, the most appropriate segmentation result according to fuzzy membership values derived from the SVM classification. Our results show that mean-shift segmentation and SVM-based classification provide an effective framework for delineation and classification of a particular landform. Variable bandwidths and terrain parameter weightings were identified as being crucial for consideration of intra-class variability, and, in turn, for a constantly

  7. 41 CFR 102-2.140 - What elements of plain language appear in the FMR? (United States)


    ... 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... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language...

  8. 13 CFR 120.172 - Flood-plain and wetlands management. (United States)


    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Flood-plain and wetlands... Flood-plain and wetlands management. (a) All loans must conform to requirements of Executive Orders 11988, “Flood Plain Management” (3 CFR, 1977 Comp., p. 117) and 11990, “Protection of Wetlands” (3 CFR...

  9. 44 CFR 60.2 - Minimum compliance with flood plain management criteria. (United States)


    ... assure that its comprehensive plan is consistent with the flood plain management objectives of this part. (h) The community shall adopt and enforce flood plain management regulations based on data provided..., the community shall not adopt and enforce flood plain management regulations based upon modified data...

  10. Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina (United States)

    Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon


    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...

  11. Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina (United States)

    Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila


    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...

  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)


    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. Formation mechanism of land subsidence in the North China Plain (United States)

    Guo, Haipeng; Cheng, Guoming


    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

  14. Plain abdominal film and abdominal ultrasound in intestine occlusion

    International Nuclear Information System (INIS)

    Amodio, C.; Antico, E.; Montesi, A.; Zaccarelli, A.


    Plain film of the abdomen is widely used in the diagnostic evaluation of intestinal occlusion. Even though this technique can yield a panoramic and high-resolution view of gas-filled intestinal loops, several factors, such as type and duration of occlusion, neurovascular status of the intestine and general patient condition, may reduce the diagnostic specificy of the plain film relative to the organic or functional nature of the occlusion. From 1987 to 1989, fifty-four patients with intestinal occlusion were studied combining plain abdominal film with abdominal ultrasound (US). This was done in order to evaluate whether the additional information obtained from US could be of value in better determining the nature of the ileus. US evaluation was guided by the information already obtained from plain film which better demonstrates gas-filled loops. The results show that in all 27 cases of dynamic ileus (intestinal ischemia, acute appendicitis, acute cholecistis, acute pancreatitis or blunt abdominal trauma) US demonstrates: intestinal loops slightly increased in caliber, with liquid content, or loops containing rare hyperechoic particles, intestinal wall thickening and no peristalsis. In 27 cases of acute, chronic or complicated mechanical ileus (adhesions, internal hernia, intestinal neoplasm, peritoneal seedings) US shows: 1) in acute occlusion: hyperperistaltic intestinal loops containing inhomogeneous liquid; 2) in chronic occlusion: liquid content with a solid echigenic component; 3) in complicated occlusion: liquid stasis, frequent increase in wall thickness, moderate peritoneal effusion and inefficient peristalsis. In conclusion, based on the obtained data, the authors feel that the combination of plain abdominal film and abdominal US can be useful in the work-up of patient with intestinal occlusion. The information provided by US allows a better definition of the nature of the ileus

  15. Acute paediatric ankle trauma: MRI versus plain radiography

    International Nuclear Information System (INIS)

    Lohman, M.; Kivisaari, A.; Kivisaari, L.; Vehmas, T.


    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.)

  16. Root-collar diameter and third-year survival of three bottomland hardwoods planted on former agricultural fields in the Lower Mississippi Alluvial Valley (United States)

    Emile S. Gardiner; Douglass F. Jacobs; Ronald P. Overton; George Hernandez


    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,...

  17. A Real Options Method for Estimating the Adoption Potential of Forestry and Agroforestry Systems on Private Lands in the Lower Mississippi Alluvial Valley, USA (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt


    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...

  18. A real options model to assess the role of flexibility in forestry and agroforestry adoption and disadoption in the Lower Mississippi Alluvial Valley (United States)

    Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt


    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...

  19. 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


    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

  20. 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.


    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)

  1. 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


    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.

  2. Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil). (United States)

    Camargo, M; Giarrizzo, T; Jesus, A J S


    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.

  3. Composition and distribution of Darwinulidae (Crustacea, Ostracoda in the alluvial valley of the upper Paraná River, Brazil

    Directory of Open Access Journals (Sweden)

    J. Higuti

    Full Text Available The occurrence and abundance of darwinulid ostracods, as well as environmental factors influencing these patterns, were investigated in the alluvial valley of the upper Paraná River. Ostracods were sampled from several substrates, like littoral sediments and pleuston, which included several aquatic macrophytes species, from 31 localities (lentic and lotic belonging to different riverine systems. Eight darwinulid species were found, representing all genera from this family. Alicenula serricaudata, Vestalenula pagliolii, and Penthesilenula brasiliensis were the most common species. Cluster analysis based on the composition and abundance of darwinulid communities revealed the presence of five associations. Darwinula stevensoni, Vestalenula botocuda, and Penthesilenula aotearoa were almost exclusive to lotic environments. A Mantel multiple test showed that the occurrence and distribution of darwinulid ostracods were significantly related to types of habitat and systems, but not to abiotic variables. It thus seems that the hydrodynamic fluctuations of these environments are probably more important to darwinulid distribution than the limnological characteristics.

  4. Characterising alluvial aquifers in a remote ephemeral catchment (Flinders River, Queensland) using a direct push tracer approach (United States)

    Taylor, Andrew R.; Smith, Stanley D.; Lamontagne, Sébastien; Suckow, Axel


    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. resources in unconsolidated sedimentary aquifers in remote data sparse areas.

  5. Analysis and assessment on heavy metal sources in the coastal soils developed from alluvial deposits using multivariate statistical methods. (United States)

    Li, Jinling; He, Ming; Han, Wei; Gu, Yifan


    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.

  6. Evidence of historical mining inferred from metal concentration of alluvial sediments in the Bernese Alps (United States)

    Carvalho, Filipe; Schulte, Lothar


    Metal pollution is normally associated with modern day industrialization. However, evidences of anthropogenic metal pollution date back to the Palaeolithic, were the domestication of fire contributed to an increase of trace metals released from the burning wood. Large-scale metal pollution started during the Roman period with the increase of mining and smelting activities. The production of metals during this period was quite rudimentary and highly polluting, contributing to a raise of metal concentrations in the atmosphere and subsequently in sediments and soils. Towards the modern period, production methods were improved, especially since the industrial revolution, but continued to release pollutants to the environment. The aim of this study is to identify periods of increased mining activity though the analysis of sedimentary records. For this purpose, we study the geochemical response of trace metals in sedimentary cores from the Aare and Lütschine delta plains, located at the Bernese Alps. The focus of this analysis is the detection of metal concentration anomalies from the last 3000 years. The analysis is based on the X-Ray Fluorescence (AVATECH XRF core scanner) response of the chemical elements copper (Cu), zinc (Zn) and lead (Pb) contained in eight cores with depths down to 10 meter. All data was filtered in order to remove the noise from natural processes such as the increase of trace metal concentrations in organic rich horizons and to select the highest peaks of these metals. Results show similar trends in all the analysed cores and indicate three major pulses of trace metal concentration during the Roman Period, Early Medieval Age and a general increase of metal concentration during the Modern era, which can evidence mining and smelting activities. Periods of lower trace metal concentrations and shifts in concentration trends relate accurately with central Europe social and economic transitions, migratory events and significant demographic variations

  7. Debris flood hazard documentation and mitigation on the Tilcara alluvial fan (Quebrada de Humahuaca, Jujuy province, North-West Argentina) (United States)

    Marcato, G.; Bossi, G.; Rivelli, F.; Borgatti, L.


    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.

  8. 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


    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.

  9. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan


    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses the unconsolidated terrace deposits and alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer extends over an area of 285 square miles and is used for irrigation and domestic purposes. Granite and the Hennessey Formation outcrop in northern parts of the aquifer where alluvial deposits are absent. These outcrops were included as part of the aquifer in a thesis that modeled the ground-water flow in the aquifer. Most of the aquifer boundaries and some of the lines in the hydraulic conductivity and recharge data sets were extracted from a published digital surficial geology data set based on a scale of 1:250,000. Most of the lines in the hydraulic conductivity, recharge, and 1969 water-level elevation contour data sets, and one line in the aquifer boundary data set were digitized from a paper map published at a scale of 1:249,695 in a thesis in which the ground-water flow in the aquifer was modeled. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  10. Simulating land management options to reduce nitrate pollution in an agricultural watershed dominated by an alluvial aquifer. (United States)

    Cerro, Itsasne; Antigüedad, Iñaki; Srinavasan, Raghavan; Sauvage, Sabine; Volk, Martin; Sanchez-Perez, José Miguel


    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.

  11. Modeling and measuring the relationships between sediment transport processes, alluvial bedforms and channel-scale morphodynamics in sandy braided rivers. (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.


    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. Integrating research and management to conserve wildfowl (Anatidae) and wetlands in the Mississippi Alluvial Valley, U.S.A (United States)

    Reinecke, K.J.; Loesch, C.R.; Birkan, Marcel


    Efforts to conserve winter habitat for wildfowl, Anatidae, in the alluvial valley of the lower Mississippi River, U.S.A., are directed by the Lower Mississippi Valley (LMV) Joint Venture of the North American Waterfowl Management Plan (NA WMP). The Joint Venture is based on a biological framework developed through cooperative planning by wildfowl researchers and managers. Important elements of the framework include: (1) numeric population goals, (2) assumptions about potential limiting factors, (3) explicit relationships between wildfowl abundance and habitat characteristics, (4) numeric foraging habitat goals, and (5) criteria for evaluating success. The population goal of the Joint Venture for the Mississippi Alluvial Valley (MA V) is to enable 4.3 million ducks to, survive winter and join continental breeding populations in spring. Currently, available data suggest that foraging habitat is the primary factor limiting duck populations in the MA II. To establish a goal for foraging habitat, we assumed the length of the wintering period is 110 days and calculated that a population of 4.3 million breeding ducks (plus 15% to account for winter mortality) would need 546 million duck-days of food in the preceding winter. Then, we used estimates of daily energy requirements, food densities, and food energy values to calculate the carrying capacity or number of duck-days of food available in the three primary foraging habitats in the MAV (flooded croplands, forested wetlands, and moist-soil wetlands). Thus, availability of foraging habitat can be used as a criterion for evaluating success of the Joint Venture if accurate inventories of foraging habitat can be conducted. Development of an explicit biological framework for the Joint Venture enabled wildfowl managers and researchers to establish specific objectives for management of foraging habitat and identify priority problems requiring further study.

  13. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region (United States)

    Zúñiga de León, David; Kershaw, Stephen; Mahan, Shannon


    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.

  14. Integrated hydrological modelling of the North China Plain

    DEFF Research Database (Denmark)

    Shu, Yunqiao; Villholth, Karen G.; Jensen, Karsten Høgh


    to and the associated dynamics of the alluvial aquifers based on climatic conditions, land use, soil characteristics, irrigation and coupled unsaturated-saturated zone processes. The model was auto-calibrated for the period 1996–2002 against daily observations of groundwater head from wells distributed across the 7230...... for scenario analysis of the effect of different cropping rotations, irrigation intensity, and other water management options, like the implementation of the South to North Water Transfer (SNWT) project. The model analysis verified that groundwater tables in the region are subject to steep declines (up to 1 m...... solely reverse declining water tables across the region. Combining the SNWT project and implementing region-wide crop and irrigation system changes, including deficit irrigation, wastewater irrigation, and alternating winter fallow, provides a feasible means to stabilize groundwater levels in the area....

  15. 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.


    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

  16. Ocean-Bottom Topography: The Divide between the Sohm and Hatteras Abyssal Plains. (United States)

    Pratt, R M


    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.

  17. A Flood Detection and Mapping Algorithm Using MODIS Data: Assessment of Extreme Flooding Events in Eastern Ganga Plains (2000-2015) (United States)

    Sprigg, W. A.; Patel, S.; Prasad, A. K.; Sarkar, B. C.


    Flood, a hydrological extreme, is a dominant and frequent phenomena over the eastern Ganga Plains comprising of alluvial plains of Bihar and adjoining Nepal Himalaya. Flood affects major parts of Bihar where Gandak and Koshi are the major tributaries of Ganga River causing inundation during the monsoon season. Due to heavy rainfall in the Eastern Himalaya and adjoining regions, the river discharge increases several folds causing severe flood in plains. Moderate Resolution Imaging Spectroradiometer (MODIS) derived data at 250 m resolution (year 2000-2015) have been used to identify flood water and calculate daily water fraction (water cover) using model adopted from previous studies. During the monsoon season, cloud cover in daily images is found to be extremely high leading to lot of gaps in the form of missing data. To account for missing grid cell values, an adaptive polynomial filter (Savitzky-Golay) have been used to fit the time series of daily data for each grid cell. The missing values in daily images have been filled with calculated values to create daily time series of flood water. Landsat data at 30 m grid resolution have been used to verify flood water detection algorithm used in this study. Time series analysis of satellite derived data reveal a strong spatial and temporal variation in the extent, duration and frequency (inter-annual and intra-annual) of flooding event over the study region. Statistical analysis of IDF (intensity, duration, and frequency) and trend have been carried out to identify regions which show greater flood risk. Reoccurrence interval and length of flooding event in the study region is found to be high compared to other river basins in the western India. Based on the historical occurrence of flood, the study area have been classified into different flood hazard zones where flood mitigation and management need to be prioritized. MODIS based flood monitoring and mapping model used in this study can be used for monitoring and

  18. A Wear Geometry Model of Plain Woven Fabric Composites

    Directory of Open Access Journals (Sweden)

    Gu Dapeng


    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.

  19. Tear Gas, Expanding Bullets and Plain-Clothed Personnel

    DEFF Research Database (Denmark)

    Wiesener, Cornelius Rust


    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...... under human rights law. Surprisingly, the legal challenges arising from their potential use in modern military operations have so far received only limited scholarly attention. This article tries to fill that gap and endeavours to contribute to the broader debate on the interplay between human rights...... and humanitarian law in (international) military operations. Drawing on the relevant preparatory works as well as subsequent practice and recent jurisprudence, this article shows that the humanitarian law rules on the use of riot control agents, expanding bullets and plain-clothed personnel provide...

  20. Three-dimensional stress analysis of plain weave composites (United States)

    Whitcomb, John D.


    Techniques were developed and described for performing three-dimensional finite element analysis of plain weave composites. Emphasized here are aspects of the analysis which are different from analysis of traditional laminated composites, such as the mesh generation and representative unit cells. The analysis was used to study several different variations of plain weaves which illustrate the effects of tow waviness on composite moduli, Poisson's ratios, and internal strain distributions. In-plane moduli decreased almost linearly with increasing tow waviness. The tow waviness was shown to cause large normal and shear strain concentrations in composites subjected to uniaxial load. These strain concentrations may lead to earlier damage initiation than occurs in traditional cross-ply laminates.

  1. The measurement of plain weft-knitted fabric stiffness

    International Nuclear Information System (INIS)

    Mohamad, Ayhan Haji; Cassidy, Thomas; Brydon, Alan; Halley, Dave


    A new instrument and a test method are presented in this paper that can evaluate the stiffness of plain weft-knitted fabrics. The WIRA Instrumentation Tester can measure torsion data for various flexible fibre assemblies whilst they are being twisted. The torsional properties of two types of fabrics, namely nonwoven and knitted fabrics, were analyzed. Then, comparisons between bending rigidity and torsional rigidity have been conducted using FAST-2, Shirley, Heart Loop and the new WIRA method for the assessment of fabric stiffness. The results show high correlation between bending rigidity and torsional rigidity in assessment of nonwoven fabric stiffness; they also reveal that the WIRA tester and torsional rigidity are more suitable for characterizing the stiffness of plain weft-knitted fabrics than the other test methods. (paper)

  2. Survey of groundwater chemical pollution in the Borazjan plain

    Directory of Open Access Journals (Sweden)

    Jaber Mozafarizadeh


    Full Text Available Background: Nitrate due to its high water solubility, poor absorption and having stable composition in the water, has been studied as the best index to indicate groundwater contamination. Borazjan, located in the north of Bushehr province, is one of fertile plains which nitrate contamination of groundwater has occurred in the most parts of it. Detecting the source of pollution and the most vulnerable areas were the aims of this study. Material and Methods: In this study, hydrochemical quality, especially in terms of nitrate, sulfate, chloride sodium, spatial and temporal variations and the origin of them in the groundwater of Borazjan plain, are studied. Groundwater samples from 12 wells were collected in April and August 2012 and assessed to determine the parameters of hydrochemistry and pollution. Results: Based on these results, severe nitrate contamination of groundwater, especially in the southern part of the plain, by agricultural activities, cesspool wells, domestic sewage and livestock and poultry wastewater the influence of the effluent from the aviculture, were occurred. Also, the quality of groundwater resources showed that concentration of Cl- , Na+, SO42- , and NO3- are more than standard limit and only in some areas of plain, concentration of ions such as NO3- and Na+ is less than the standard limit. Conclusion: According to the results of this study, using chemical fertilizers in terms of time period and amount of consumption should be properly managed. Furthermore, domestic wastewater, livestock and poultry wastewater should be controlled and the monitoring system for measuring the exact quantity and quality of groundwater resources must be completed.

  3. 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 ...

  4. 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


    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.)

  5. Structural Reliability of Plain Bearings for Wave Energy Converter Applications

    Directory of Open Access Journals (Sweden)

    Simon Ambühl


    Full Text Available The levelized cost of energy (LCOE from wave energy converters (WECs needs to be decreased in order to be able to become competitive with other renewable electricity sources. Probabilistic reliability methods can be used to optimize the structure of WECs. Optimization is often performed for critical structural components, like welded details, bolts or bearings. This paper considers reliability studies with a focus on plain bearings available from stock for the Wavestar device, which exists at the prototype level. The Wavestar device is a point absorber WEC. The plan is to mount a new power take-off (PTO system consisting of a discrete displacement cylinder (DDC, which will allow different hydraulic cycles to operate at constant pressure levels. This setup increases the conversion efficiency, as well as decouples the electricity production from the pressure variations within the hydraulic cycle when waves are passing. The new PTO system leads to different load characteristics at the floater itself compared to the actual setup where the turbine/generator is directly coupled to the fluctuating hydraulic pressure within the PTO system. This paper calculates the structural reliability of the different available plain bearings planned to be mounted at the new PTO system based on a probabilistic approach, and the paper gives suggestions for fulfilling the minimal target reliability levels. The considered failure mode in this paper is the brittle fatigue failure of plain bearings. The performed sensitivity analysis shows that parameters defining the initial crack size have a big impact on the resulting reliability of the plain bearing.

  6. Long term acroecosystem research in the Southern Plains (United States)

    Jean L. Steiner; Patrick J. Starks; Jurgen Garbrecht; Daniel Moriasi; Paul Bartholomew; Jim Neel; Kenneth E. Turner; Brian Northup


    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...

  7. Suspended particulate studies over the Madeira Abyssal Plain

    International Nuclear Information System (INIS)

    Simpson, W.R.


    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)

  8. Orthorad - the online reference database of skeletal plain film radiography

    International Nuclear Information System (INIS)

    Hinkmann, F.M.; Heberlein, C.; Greess, H.; Ketelsen, D.; Klose, K.J.; Grunewald, M.


    Purpose: it is evident that there is a growing need for internet-based reference databases for reasons of practicability and due to the increasing use of reporting on digital workstations. The main advantages of online databases are expected with respect to plain film radiography and cross-sectional imaging. A reference database of skeletal plain film radiography was to be created using the Orthorad program. Materials and methods: the most important standard settings and special images of young and healthy adults in plain film radiography were collected over one year. All samples were approved for the Orthorad database by a board qualified radiologist. Based on the workflows of radiographers and radiologists, the records were organized by body part ( This logical data structure will ensure that the tool serves as a source of information in two ways: On the one hand, the radiographer can access information on positioning, tube voltage and cassette format. On the other hand, the radiologist receives important knowledge regarding X-ray anatomy, reference data regarding the human skeleton, and information about the correct reporting for an image. (orig.)

  9. Evaluation of Holocene pollen records from the Romanian Plain. (United States)



    This study is a critical review of pollen analyses carried out on Holocene sequences from 15 sites in and near the Romanian Plain. Three sites come from natural sediments, 10 sites are from anthropogenic deposits and two are from both anthropogenic and natural settings. The general reconstruction is of a steppe-forest-steppe vegetation through the Holocene. The nature of the deposits, however, casts doubts on this reconstruction. Deposits of archaeological sites generally yield pollen spectra that are influenced by human activities and thus unsuitable for vegetation reconstructions. Loess deposits are also unfavorable for pollen preservation because of high pH and porosity. Consequently, pollen spectra from loess deposits are strongly biased by selective pollen destruction. Research and experiments carried out by several authors suggest that spectra dominated by Asteraceae, Poaceae, Chenopodiaceae or Pinus pollen in soils and loess are a result of selective pollen destruction, especially if low pollen concentrations, progressive pollen deterioration or high frequencies of deteriorated or unidentifiable pollen are evidenced. The fact that pollen records from the Romanian Plain come from loess, alkaline peat or archaeological sites reduces their reliability for reconstructions of vegetation. The vegetation history of similar regions in Hungary, Bulgaria and Turkey suggests that early Holocene steppe vegetation was gradually replaced by forest or forest-steppe vegetation in the late Holocene. Records from lake sediments are required to find out whether the Holocene vegetation history of the Romanian Plain was similar.

  10. Diagnosis of lumbar central spinal stenosis by plain radiography

    International Nuclear Information System (INIS)

    Ilkko, E.


    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

  11. 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


    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.)

  12. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Vesali Naseh


    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.

  13. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran (United States)

    Berndtsson, Ronny; Adamowski, Jan; Sadatipour, Elaheh


    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. PMID:29361791

  14. Systematic assessment of constipation on plain abdominal radiographs in children

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, Maurice van den; Graafmans, Doortje [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nievelstein, Rutger; Beek, Erik [Wilhelmina Children' s Hospital, Department of Paediatric Radiology, Utrecht (Netherlands)


    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 ({kappa} values of 0.88 and 1.00, respectively, P<0.05). Furthermore, the interobserver agreement was also high: {kappa} 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.)

  15. 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


    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

  16. Acute neuropathic joint in diabetic foot: Plain radiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Dae Young; Kang, Heung Sik; Sim, Jung Suk; Yoon, Yong Kyu; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    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.

  17. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran. (United States)

    Vesali Naseh, Mohammad Reza; Noori, Roohollah; Berndtsson, Ronny; Adamowski, Jan; Sadatipour, Elaheh


    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.

  18. The migration, dissolution, and fate of chlorinated solvents in the urbanized alluvial valleys of the southwestern USA (United States)

    Jackson, R. E.

    The migration, dissolution, and subsequent fate of spilled chlorinated solvents in the urban alluvial valleys of the southwestern U.S. appear to be governed by a unique set of hydrogeologic and geochemical processes occurring within terrigeneous clastic depositional systems. The alluvial and lacustrine fill of the basins, the trapping of solvents in fine-grained sediments beneath the urbanized valley centers, the oxic conditions typical of the deeper alluvium, and the contaminant-transport patterns produced by large-scale basin pumping combine to produce long aqueous-phase plumes derived from the dissolution of trapped chlorinated solvents. Although of limited aqueous solubility, these dense solvents are sufficiently mobile and soluble in the southwestern alluvial valleys to have produced aqueous plumes that have migrated several kilometers through the deeper alluvium and have contaminated valuable water-supply well fields in California, Arizona, and New Mexico. The typical length of these plumes and the presence of oxic groundwater indicate that it is unlikely that natural attenuation will be a practical remedial option in the southwestern alluvial valleys or in other alluvial systems in which similar hydrogeologic and geochemical conditions exist. Résumé La migration, la dissolution et l'évolution consécutive des rejets de solvants chlorés dans les vallées alluviales du sud-ouest des États-Unis paraissent déterminées par un même ensemble de processus hydrogéologiques et géochimiques intervenant dans des formations de dépôts clastiques terrigènes. Les remplissages alluviaux et lacustres des bassins, le piégeage des solvants par des sédiments fins sous les centres des vallées urbanisées, les conditions oxiques typiques des alluvions plus profondes et les types de transport de contaminants provoqués par le pompage à l'échelle du bassin se combinent pour produire des panaches, étendus dans la phase aqueuse, provenant de la dissolution de

  19. The role of tropical cyclones on landscape dynamics in southern Baja California, Mexico based on Late Pleistocene-Holocene alluvial stratigraphy (United States)

    McDonald, Eric; Antinao, Jose Luis; Rhodes, Edward J.; Brown, Nathan; Gosse, John


    Region-wide alluvial records provide evidence that time-transgressive changes in climate can be a major driver of landscape evolution. Historically, landfall of eastern Pacific tropical cyclones in southwestern North America during the late summer and early fall provide the strongest storms that have demonstrated geomorphic impact on the landscape. The alluvial fan record of the southern portion of Baja California (Mexico) was investigated to determine if linkages exist between region-wide fluvial deposits and tropical cyclones. The regional distribution and Pleistocene to Holocene morphostratigraphy of alluvial fans has been established for the southern portion of Baja California with primary focus on the La Paz and San José del Cabo basins. Six discrete morphopedosedimentary alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development further reinforced with geochronology using radiocarbon, optically stimulated luminescence and cosmogenic depth-profiles. A first phase of regional aggradation began before ~ 100 ka (Qt1) and culminated ~10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units are conformed of multiple 1-3 m thick alluvial packages deposited in upper-flow regime and representing individual storms. Aggradational units (Qt1-Qt4) covered broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are mostly confined to channels of ~0.5-2 km width. Continuous deposition of the thicker sequences is demonstrated by closely spaced luminescence dates in vertical profiles. In a few places disconformities between major units are evident and indicated by partly eroded buried soils. Analysis of historical terraces as part of the younger units

  20. Characterization of alluvial dust sources and their temporal development - a multi-sensor approach for the Aïr Massif, Niger (United States)

    Feuerstein, Stefanie; Schepanski, Kerstin


    One of the world's largest sources of atmospheric dust is the Sahara. It is said that 55% of the total global dust emission can be linked to the desert in northern Africa. Thus, understanding the Saharan dust sources is of great importance to estimate the total global dust load and its variability. Especially one type of dust sources has gained attention in dust research in recent years: The emission of dust from sediments formed by hydrologic processes, so called alluvial dust sources. These sediments were either formed in the past under the influences of a more humid paleoclimate or are deposited recently, e.g. during strong precipitation events when surficial runoff leads to the activation of wadi systems or to the occurrence of flash floods. Especially the latter phenomenon is able to deliver a huge amount of potentially erodible sediments. The research presented here focuses on the characterization of these alluvial dust sources with special attention on their temporal variability in relation to wet and dry phases. A study area covering the Aïr Massif in Niger is analysed over a four years time span from January 2013 to December 2016. The whole cycle from sediment formation to dust emission is illustrated by using data of various satellite sensors that are able to capture the processes taking place at the land surface as well as in the atmosphere: (1) The rainfall distribution for the study area is shown by time series of the TRMM precipitation estimates. A catchment analysis of the area helps to estimate the amount of surficial runoff and to detect areas of potential sediment accumulation. (2) Changes in the sediment structure of the land surface are analysed using atmospherically corrected time series of NASA's Landsat-8 OLI satellite. A land cover classification shows the distribution of alluvial sediments over the area; fresh layers of alluvial deposits are detected. Furthermore, the evolution of the vegetation cover, which inhibits dust emission, is

  1. A New Boundary for the High Plains - Ogallala Aquifer Complex (United States)

    Haacker, E. M.; Nozari, S.; Kendall, A. D.


    In the semi-arid Great Plains, water is the key ingredient for crop growth: the difference between meager yields for many crops and an agricultural bonanza. The High Plains-Ogallala Aquifer complex (HPA) underlies 452,000 square kilometers of the region, and over 95% of water withdrawn from the aquifer is used for irrigation. Much of the HPA is being pumped unsustainably, and since the region is heavily reliant on this resource for its social and economic health, the High Plains has been a leader in groundwater management planning. However, the geographic boundary of the High Plains region fails to reflect the hydrogeological realities of the aquifer. The current boundary, recognizable from countless textbooks and news articles, is only slightly modified from a version from the 1980's, and largely follows the physiographic borders of the High Plains - defined by surface features such as escarpments and rivers - rather than the edges of water-bearing sediment sufficient for high-volume pumping. This is supported by three lines of evidence: hydrogeological observations from the original aquifer boundary determination; the extent of irrigated land, as estimated by MODIS-MIrAD data; and statistical estimates of saturated thickness, incorporating improved maps of the aquifer base and an additional 35 years of water table measurements. In this project, new maps of saturated thickness are used to create an updated aquifer boundary, which conforms with the standard definition of an aquifer as a package of sediment that yields enough water to be economically pumped. This has major implications for social and physical models, as well as water planning and estimates of sustainability for the HPA. Much of the area of the HPA that has been labeled `sustainable' based upon estimates of recharge relative to pumping estimates falls outside the updated aquifer boundary. In reality, the sustainably-pumped area of this updated aquifer boundary is far smaller—a fact that if more

  2. Some simple procedures for the calculation of the influence radius and well head protection areas (theoretical approach and a field case for a water table aquifer in an alluvial plain

    Directory of Open Access Journals (Sweden)

    Alessio Fileccia


    Full Text Available The paper describes some simple methodologies for the delineation of well-head protection areas, together with an overview of the main regulations published in Italy and Europe. Starting from a general explanation of the main parameters, like the radius of influence and the zone of capture in homogeneous isotropic aquifers, basic methodologies suggested in the literature are then illustrated. Different criteria are involved: from the simple 200 m radius, to more complex analytical and numerical simulations. Five different approaches are applied and compared, to a well field in a water table aquifer along a river. Results have shown that, while simpler methods can be satisfactory at a first stage of the study, they fail to account correctly, for local heterogeneities. On the other hand the more accurate description of the aquifer obtained with a full numerical model requires extensive time, expertise and amount of data, that are not always available in case of small water supply systems. As many Authors have underlined, one of the most effective outcome of the numerical tool, lays in the capability to increase our knowledge on the groundwater dynamics of the system and the amount of the sustainable yield.

  3. Wind-blown sand movement periods on the Nyírség alluvial fan, Hungary (United States)

    Buró, Botond; Lóki, József; Sipos, György; Négyesi, Gábor; Andrási, Bence; Jakab, Attila; Félegyházi, Enikő; Molnár, Mihály


    Wind-blown sand movement periods on the Nyírség alluvial fan, Hungary The Nyírség is an alluvial fan, was built by rivers, which were flown down from the NE Carpathians. When the weather was dry, wind-blown sand was blowed out and the wind started to develop the aeolian landforms. The first significant sand movements in the Nyírség was in the Upper plenniglacial and the Late glacial. The main landforms of the Nyírség were developed at this time. The aeolic transformation of the land was not completed in the Nyírség at the end of the Pleistocene. In the Holocene the sand moved within small area, mainly by anthropogenic impact. Our aim is clarify the age of the wind-blown sand movements period, with different absolute (Radiocarbon dating method, OSL), and relative (Archaeological finds, Pollen analyses) dating methods. We have collected for the age determining charcoal from many sand quarry (Gégény, Kántorjánosi, Nyíradony, Nagyvarsány, Máriapócs and Lövőpetri) which contain fossil soil layer. For the OSL measurements samples were collected from Baktalórántháza, Gégény and Kántorjánosi sand quarries. We collected samples from 5 places for the pollen analyses (Nyírtanya, Máriapócs, Nyírbéltek-Nyírlúgos, Nyírábrány, Vámospércs), and also from an archaeological excavation (Nyíregyháza- Oros). The new age dates show us, that in the Nyírség the first significant sand movements were in the cold and drier period of the Upper pleniglacial and Late glacial (Baktalórántháza, Nyírtanya, Vámospércs). At the end of the Pleistocene the sand movements not competed in the Nyírség (Gégény, Kántorjánosi, Nyírábrány). In the Holocene there were many little sand movement periods, mainly caused by anthropogenic impact (Nyíradony, Nyíregyháza-Oros). The research was supported by the European Union and the State of Hungary, co-financed by the European Regional Development Fund in the project of GINOP-2.3.2.-15-2016-00009 'ICER

  4. A Dataset of Rock Strength Along the Mixed Bedrock-alluvial Colorado River-Quantifying a Fundamental Control in Geomorphology (United States)

    Pederson, J. L.; Bursztyn, N.


    Bedrock strength is a key parameter in slope stability, landscape erosion, and fluvial incision, though it is typically ignored or at best indirectly constrained in models, as with the k erodability parameter in stream-power formulations. Indeed, empirical datasets of rock strength suited to address geomorphic questions are rare, in part because of the difficulty in measuring those rocks that are heterolithic, weak, or poorly exposed. We have completed a large dataset of measured bedrock strength organized by rock units exposed along the length of the trunk Colorado-Green river through the Colorado Plateau of the western U.S. Measurements include Selby RMS, fracturing, and field compressive tests at 168 localities, as well as 672 individual-sample tensile-strength tests in the laboratory. These rock strength results are compared to geomorphic metrics of unit stream power, river gradient, valley-bottom width, and local relief through the arid Colorado Plateau. Our measurements trend coherently and logically with bedrock type and age/induration, especially in the case of tensile strength and when the influence of fracturing is also considered, signs that the dataset is robust. Focusing on bedrock (rather than alluvial) reaches of the fluvial transect and tensile strength, there is a positive rank-correlation and a strong power-law correlation between reach-averaged rock strength and unit stream power, as well as an elegant linear relation between tensile strength and river gradient. To address the problem of immeasureable rock types, we utilize the inverse power-law scaling between tensile strength and valley-bottom width to estimate the "effective" tensile strength of heterolithic, shale-rich bedrock in alluvial reaches. These results suggest that tensile strength varies to at least an order-of-magnitude smaller values than evident with directly testable rocks in this landscape, with implications for scaling erodibility parameters. Overall, results lead to the

  5. Redox Fluctuation Influences Viral Abundance in the Reduced Zone of a Shallow Alluvial Aquifer in Rifle, CO (United States)

    Pan, D.; Williams, K. H.; Robbins, M.; Weber, K. A.


    Naturally reduced zones (NRZs) within alluvial aquifers contain naturally elevated concentrations of organic carbon (OC) and can play a role in controlling the fate of redox-active contaminants. OC in NRZs stimulates microbial activity through coupling of OC oxidation to reduction of subsurface electron acceptors. Stimulation of the indigenous microbial community also results in the stimulation of the viral community. Viruses are the most abundant biological entity on Earth and can indirectly influence carbon cycling by infecting and lysing host cells, resulting in release of OC bound in biomass. In the alluvial aquifer near Rifle, CO, prior acetate injection resulted in reductive immobilization of U and a reduced zone simulating a NRZ, with elevated ferrous iron and sulfide (53.2-62.5 µM and 0.2-3.1 µM, respectively). To study the effects of redox fluctuations in a RZ, oxygenated groundwater was injected. Prior to injection, groundwater was suboxic (0.05-0.11 mg/L). Amended O2 was immediately consumed in the RZ. While cell numbers didn't significantly increase, viruses increased from 1.1x106-2.1x106 mL-1 to 2.3x106-4.6x106 mL-1. VCR increased 1.8-3.4 fold from 3.9-10.1 to 11.0-17.9, demonstrating microbial activity. These changes were associated with large fluctuations of groundwater dissolved OC, suggesting viral release of OC from cellular biomass. Groundwater ORP decreased from an initial -146 mV - -132 mV to -317 mV - -304 mV, indicating an increase in the supply of available electron donors. Thus, rather than expected oxidative solubilization of U following amendment of O2, soluble U decreased, suggesting likely U reduction in the RZ. Fe and S fluctuated, but changes were not associated with aqueous U. Across the whole floodplain, viral abundance is correlated to groundwater dissolved OC, suggesting that viruses may be contributing to the liberalization of dissolved OC from biomass in NRZs, allowing turnover of carbon and reduction of contaminants of

  6. Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system (United States)

    Morway, Eric D.; Gates, Timothy K.; Niswonger, Richard G.


    Some of the world’s key agricultural production systems face big challenges to both water quantity and quality due to shallow groundwater that results from long-term intensive irrigation, namely waterlogging and salinity, water losses, and environmental problems. This paper focuses on water quantity issues, presenting finite-difference groundwater models developed to describe shallow water table levels, non-beneficial groundwater consumptive use, and return flows to streams across two regions within an irrigated alluvial river valley in southeastern Colorado, USA. The models are calibrated and applied to simulate current baseline conditions in the alluvial aquifer system and to examine actions for potentially improving these conditions. The models provide a detailed description of regional-scale subsurface unsaturated and saturated flow processes, thereby enabling detailed spatiotemporal description of groundwater levels, recharge to infiltration ratios, partitioning of ET originating from the unsaturated and saturated zones, and groundwater flows, among other variables. Hybrid automated and manual calibration of the models is achieved using extensive observations of groundwater hydraulic head, groundwater return flow to streams, aquifer stratigraphy, canal seepage, total evapotranspiration, the portion of evapotranspiration supplied by upflux from the shallow water table, and irrigation flows. Baseline results from the two regional-scale models are compared to model predictions under variations of four alternative management schemes: (1) reduced seepage from earthen canals, (2) reduced irrigation applications, (3) rotational lease fallowing (irrigation water leased to municipalities, resulting in temporary dry-up of fields), and (4) combinations of these. The potential for increasing the average water table depth by up to 1.1 and 0.7 m in the two respective modeled regions, thereby reducing the threat of waterlogging and lowering non-beneficial consumptive use

  7. Late Holocene evolution of a coupled, mud-dominated delta plain-chenier plain system, coastal Louisiana, USA (United States)

    Hijma, Marc P.; Shen, Zhixiong; Törnqvist, Torbjörn E.; Mauz, Barbara


    Major deltas and their adjacent coastal plains are commonly linked by means of coast-parallel fluxes of water, sediment, and nutrients. Observations of the evolution of these interlinked systems over centennial to millennial timescales are essential to understand the interaction between point sources of sediment discharge (i.e. deltaic distributaries) and adjacent coastal plains across large spatial (i.e. hundreds of kilometres) scales. This information is needed to constrain future generations of numerical models to predict coastal evolution in relation to climate change and other human activities. Here we examine the coastal plain (Chenier Plain, CP) adjacent to the Mississippi River delta, one of the world's largest deltas. We use a refined chronology based on 22 new optically stimulated luminescence and 22 new radiocarbon ages to test the hypothesis that cyclic Mississippi subdelta shifting has influenced the evolution of the adjacent CP. We show that over the past 3 kyr, accumulation rates in the CP were generally 0-1 Mt yr-1. However, between 1.2 and 0.5 ka, when the Mississippi River shifted to a position more proximal to the CP, these rates increased to 2.9 ±1.1 Mt yr-1 or 0.5-1.5 % of the total sediment load of the Mississippi River. We conclude that CP evolution during the past 3 kyr was partly a direct consequence of shifting subdeltas, in addition to changing regional sediment sources and modest rates of relative sea-level (RSL) rise. The RSL history of the CP during this time period was constrained by new limiting data points from the base of overwash deposits associated with the cheniers. These findings have implications for Mississippi River sediment diversions that are currently being planned to restore portions of this vulnerable coast. Only if such diversions are located in the western portion of the Mississippi Delta plain could they potentially contribute to sustaining the CP shoreline. Our findings highlight the importance of a better

  8. Geochemical Fractionations and Mobility of Arsenic, Lead and Cadmium in Sediments of the Kanto Plain, Japan. (United States)

    Hossain, Sushmita; Oguchi, Chiaki T.; Hachinohe, Shoichi; Ishiyama, Takashi; Hamamoto, Hideki


    Lowland alluvial and floodplain sediment play a major role in transferring heavy metals and other elements to groundwater through sediment water interaction in changing environmental conditions. However identification of geochemical forms of toxic elements such as arsenic (As), lead (Pb) and cadmium (Cd) requires risk assessment of sediment and subsequent groundwater pollution. A four steps sequential extraction procedure was applied to characterize the geochemical fractionations of As, Pb and Cd for 44 sediment samples including one peat sample from middle basin area of the Nakagawa river in the central Kanto plain. The studied sediment profile extended from the bottom of the river to 44 m depth; sediment samples were collected at 1m intervals from a bored core. The existing sedimentary facies in vertical profile are continental, transitional and marine. There are two aquifers in vertical profile; the upper aquifer (15-20m) contains fine to medium sand whereas medium to coarse sand and gravelly sand contain in lower aquifer (37-44m). The total As and Pb contents were measured by the X-Ray Fluorescence analysis which ranged from 4 to 23 mg/kg of As and 10 to 27 mg/kg of Pb in sediment profile. The three trace elements and major heavy metals were determined by ICP/MS and ICP/AES, and major ions were measured by an ion chromatograph. The marine sediment is mainly Ca-SO4 type. The Geochemical analysis showed the order of mobility trends to be As > Pb > Cd for all the steps. The geochemical fractionations order was determined to be Fe-Mn oxide bound > carbonate bound > ion exchangeable > water soluble for As and Pb whereas the order for Cd is carbonate bound > Fe-Mn oxide bound > ion exchangeable > water soluble. The mobility tendency of Pb and Cd showed high in fine silty sediment of marine environment than for those from continental and transitional environments. In the case of As, the potential mobility is very high (>60%) in the riverbed sediments and clayey silt

  9. Vertical distribution of 137Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation (United States)

    Mamikhin, S. V.; Golosov, V. N.; Paramonova, T. A.; Shamshurina, E. N.; Ivanov, M. M.


    Profiles of vertical 137Cs distribution in alluvial meadow soils on the low and medium levels of the Lokna River floodplain (central part of the Plavsk radioactive spot in Tula oblast) 28 years after the Chernobyl fallout have been studied. A significant increase in the 137Cs pool is revealed on the low floodplain areas compared to the soils of interfluves due to the accumulation of alluvium, which hampers the reduction of the total radionuclide pool in alluvial soils because of radioactive decay. The rate of alluvium accumulation in the soil on the medium floodplain level is lower by three times on average. An imitation prognostic model has been developed, which considers the flooding and climatic conditions in the region under study. Numerical experiments have quantitatively confirmed the deciding role of low-mobile forms in the migration of maximum 137Cs content along the soil profile in the absence of manifested erosion-accumulation processes.

  10. A combined morphometric, sedimentary, GIS and modelling analysis of flooding and debris flow hazard on a composite alluvial fan, Caveside, Tasmania (United States)

    Kain, Claire L.; Rigby, Edward H.; Mazengarb, Colin


    Two episodes of intense flooding and sediment movement occurred in the Westmorland Stream alluvial system near Caveside, Australia in January 2011 and June 2016. The events were investigated in order to better understand the drivers and functioning of this composite alluvial system on a larger scale, so as to provide awareness of the potential hazard from future flood and debris flow events. A novel combination of methods was employed, including field surveys, catchment morphometry, GIS mapping from LiDAR and aerial imagery, and hydraulic modelling using RiverFlow-2D software. Both events were initiated by extreme rainfall events (fan. The impacts of the 2011 and 2016 events on the farmland appeared similar; however, there were differences in sediment source and transport processes that have implications for understanding recurrence probabilities. A debris flow was a key driver in the 2011 event, by eroding the stream channel in the forested watershed and delivering a large volume of sediment downstream to the alluvial fan. In contrast, modelled flooding velocities suggest the impacts of the 2016 event were the result of an extended period of extreme stream flooding and consequent erosion of alluvium directly above the current fan apex. The morphometry of the catchment is better aligned with values from fluvially dominated fans found elsewhere, which suggests that flooding represents a more frequent future risk than debris flows. These findings have wider implications for the estimation of debris flow and flood hazard on alluvial fans in Tasmania and elsewhere, as well as further demonstrating the capacity of combined hydraulic modelling and geomorphologic investigation as a predictive tool to inform hazard management practices in environments affected by flooding and sediment movement.

  11. The influence of time on the magnetic properties of late Quaternary periglacial and alluvial surface and buried soils along the Delaware River, USA

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    Gary E Stinchcomb


    Full Text Available Magnetic susceptibility of soils has been used as a proxy for rainfall, but other factors can contribute to magnetic enhancement in soils. Here we explore influence of century- to millennial-scale duration of soil formation on periglacial and alluvial soil magnetic properties by assessing three terraces with surface and buried soils ranging in exposure ages from <0.01 to ~16 kyrs along the Delaware River in northeastern USA. The A and B soil horizons have higher Xlf, Ms, and S-ratios compared to parent material, and these values increase in a non-linear fashion with increasing duration of soil formation. Magnetic remanence measurements show a mixed low- and high-coercivity mineral assemblage likely consisting of goethite, hematite and maghemite that contributes to the magnetic enhancement of the soil. Room-temperature and low-temperature field-cooled and zero field-cooled remanence curves confirm the presence of goethite and magnetite and show an increase in magnetization with increasing soil age. These data suggest that as the Delaware alluvial soils weather, the concentration of secondary ferrimagnetic minerals increase in the A and B soil horizons. We then compared the time-dependent Xlf from several age-constrained buried alluvial soils with known climate data for the region during the Quaternary. Contradictory to most studies that suggest a link between increases in magnetic susceptibility and high moisture, increased magnetic enhancement of Delaware alluvial soils coincides with dry climate intervals. Early Holocene enhanced soil Xlf (9.5 – 8.5 ka corresponds with a well-documented cool-dry climate episode. This relationship is probably related to less frequent flooding during dry intervals allowing more time for low-coercive pedogenic magnetic minerals to form and accumulate, which resulted in increased Xlf. Middle Holocene enhanced Xlf (6.1 – 4.3 ka corresponds with a transitional wet/dry phase and a previously documented incision

  12. Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA (United States)

    Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.


    The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

  13. La plaine alluviale de l’Oise : milieu et système fluvial ; stratigraphie des formations alluviales et archéologie The alluvial plain of the Oise: fluvial environment and system; stratigraphy of the alluvial formation and archaeology. Report by Vincent Krier produced for Val d’Oise general council and the National Institute for Research in Preventive Archaeology, 2004

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    Patrice Rodriguez


    Full Text Available La notion de site archéologique définie par un ensemble de témoins matériels s’est élargie, depuis une vingtaine d’années, aux données sédimentaires et paléoécologiques indicatrices du contexte de conservation des vestiges et des relations passées entre l’Homme et son environnement. Plus récemment, l’étude de la morphologie des paysages, en particulier à travers celle de la cartographie historique, est venue compléter cette approche en révélant d’anciennes formes du relief et les empreintes d...

  14. The effect of iron oxidation in the groundwater of the alluvial aquifer of the Velika Morava River, Serbia, on the clogging of water supply wells

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    Majkić-Dursun Brankica


    Full Text Available The oxidation of dissolved iron(II in groundwater and precipitation on the screens and discharge pipes of water wells that tap shallow alluvial aquifers leads to the formation of well encrustations. Well clogging has a number of adverse impacts reflected in declining production capacity, increasing parasitic drawdown and growing maintenance costs of the water supply source. Chemical clogging rarely occurs as a stand-alone process in the groundwater of shallow alluvial aquifers; it is generally catalyzed by micro-organisms, the role of which is important to explain rapid blocking. This paper presents a calculation of the rate of homogeneous chemical oxidation of iron in wells that tap the alluvial aquifer of the Velika Morava River in Serbia, where there are pronounced iron hydroxide clogging issues. When the dynamic groundwater level drops to such an extent that the pumps need to be shut down, or when the well capacity is very low, the results show that there is enough time for iron encrustation to form. Iron oxidation does not occur solely inside the well; the process tends to extend into a much wider zone, beyond the well. [Projekat Ministartsva nauke Republike Srbije, br. TR37014

  15. [Effects of cadmium stress on the microbial biodiversity in purple soil and alluvial soil potted with a poplar (Populus deltoides x Populus nigra)]. (United States)

    Wang, Ao; Wu, Fu-Zhong; Yang, Wan-Qin; Zhou, Li-Qiang; Wang, Xu-Xi; Han, Yu


    Effects of current Cd contamination levels on microbial biodiversity were studied under the typical Cd contaminated soils in the Yangtze Basin. Purple soil and alluvial soil potted with a poplar (Populus deltoides x Populus nigra) were selected, and the culturable soil microbial amounts by flat method, microbial biomass and bacterial community structure by PCR-DGGE were investigated. Cd supplies significantly increased the culturable amounts of bacteria and actinomyces in purple soil, but decreased the culturable amounts of fungi and the content of microbial biomass N. Fingerprint of DGGE also showed that bacterial community structure have obviously changed under different Cd supplies. In contrast, the lower Cd supplies slightly increased the culturable amounts of bacteria and fungi in alluvial soil, but higher Cd supply treatment decreased the culturable amounts of bacteria, actinomyces and fungi, and the content of microbial biomass N. However, only a slight change was observed under different Cd supplies by DGGE fingerprint. Additionally, there were few effects of Cd supplies on the content of microbial biomass C in both purple soil and alluvial soil. The results provided basic data to understand the effects of present Cd contamination levels on soil microbial characteristics.

  16. Large to intermediate-scale aquifer heterogeneity in fine-grain dominated alluvial fans (Cenozoic As Pontes Basin, northwestern Spain): insight based on three-dimensional geostatistical reconstruction (United States)

    Falivene, O.; Cabrera, L.; Sáez, A.


    Facies reconstructions are used in hydrogeology to improve the interpretation of aquifer permeability distribution. In the absence of sufficient data to define the heterogeneity due to geological processes, uncertainties in the distribution of aquifer hydrofacies and characteristics may appear. Geometric and geostatistical methods are used to understand and model aquifer hydrofacies distribution, providing models to improve comprehension and development of aquifers. However, these models require some input statistical parameters that can be difficult to infer from the study site. A three-dimensional reconstruction of a kilometer scale fine-grain dominated Cenozoic alluvial fan derived from more than 200 continuously cored, closely spaced, and regularly distributed wells is presented. The facies distributions were reconstructed using a genetic stratigraphic subdivision and a deterministic geostatistical algorithm. The reconstruction is only slightly affected by variations in the geostatistical input parameters because of the high-density data set. Analysis of the reconstruction allowed identification in the proximal to medial alluvial fan zones of several laterally extensive sand bodies with relatively higher permeability; these sand bodies were quantified in terms of volume, mean thickness, maximum area, and maximum equivalent diameter. These quantifications provide trends and geological scenarios for input statistical parameters to model aquifer systems in similar alluvial fan depositional settings.

  17. Chronostratigraphic study of the Grottaperfetta alluvial valley in the city of Rome (Italy: investigating possible interaction between sedimentary and tectonic processes

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    G. Di Giulio


    Full Text Available We carried out geomorphologic and geological investigations in a south-eastern tributary valley of the Tiber River in Rome, the Grottaperfetta valley, aimed to reconstruct its buried geometry. Since results of the geomorphologic study evidenced anomalies of the stream beds, we performed geoelectric and boreholes prospecting to check whether recent faulting, rather than an inherited structural control, possibly contributed to the evolution of the alluvial valley. Vertical offsets of the stratigraphic horizons across adjacent boreholes were evidenced within the Late Pleistocene-Holocene alluvium and its substratum. In order to rule out the effects of irregular geometry of the alluvial deposits, we focussed on sectors where vertical offsets affected all the stratigraphic horizons (alluvium and pre-Holocene substratum, showing an increasing displacement with depth. We identified a site where repeated displacements occur coupled with a lateral variation of soil resistivity, and we drilled an oblique borehole aimed to cross and sample the possible fault zone affecting the terrain. A 7 cm thick granular layer, inclined 50°÷70° on the horizontal, was recovered 5 m b.g., and it was interpreted as the filling material of a fracture. The convergence of the reported features with independent evidence from geoelectric and geomorphologic investigations leads to hypothesize the presence of a faulting zone within the Holocene alluvial terrains and to propose the excavation of a trench to verify this hypothesis.

  18. Hydraulic properties of alluvial soil of the ebb tide of Flocos Dam in Tuparetama - Pernambuco State, Brazil

    International Nuclear Information System (INIS)

    Souza, Eduardo S.; Montenegro, Abelardo A.A.


    The soil hydraulic properties, i.e., the soil-moisture characteristic curve, Θ(h), and the hydraulic conductivity, K(h), were determined for an alluvial soil from Flocos Dam, located at Tuparetama, state of Pernambuco, Brazil. The soil characteristic curves were determined through the functional adjustment, proposed by van Genuchten, to the values obtained in field measurements with tensiometers and neutron probes, and to values obtained in laboratory in a 'pressure pan' with a porous plate. The infiltration tests were performed for the depths of 0, 20, 40, 60, and 80 cm using an infiltration disk with a diameter of 80 mm, applying water at a potential of 0, -3, -6 and -12 cm. The hydraulic conductivity of the soil was determined through the VG method proposed by Zhang, which requires the previous knowledge of the soil-moisture characteristic curve. The determination of the soil-moisture characteristic curve by the two methods, using field or laboratory measurements, yielded similar results within the range of common pressure, from -300 to -100 cm, and indicates that the experimental results are sound and coherent. The heterogeneity of soil hydraulic properties within the soil profile can be explained by the variability in soil texture and dry bulk density throughout the profile. By using the diameter of the infiltration disk and the pressure applied to the soil, it was possible to characterize the porous matrix within the clayey layer. (author)

  19. Groundwater response to serial stream stage fluctuations in shallow unconfined alluvial aquifers along a regulated stream (West Virginia, USA) (United States)

    Maharjan, Madan; Donovan, Joseph J.


    Groundwater response to stream stage fluctuations was studied in two unconfined alluvial aquifers using a year-long time series of stream stages from two pools along a regulated stream in West Virginia, USA. The purpose was to analyze spatial and temporal variations in groundwater/surface-water interaction and to estimate induced infiltration rate and cumulative bank storage during an annual cycle of stream stage fluctuation. A convolution-integral method was used to simulate aquifer head at different distances from the stream caused by stream stage fluctuations and to estimate fluxes across the stream-aquifer boundary. Aquifer diffusivities were estimated by wiggle-matching time and amplitude of modeled response to multiple observed storm events. The peak lag time between observed stream and aquifer stage peaks ranged between 14 and 95 hour. Transient modeled diffusivity ranged from 1,000 to 7,500 m2/day and deviated from the measured and calculated single-peak stage-ratio diffusivity by 14-82 %. Stream stage fluctuation displayed more primary control over groundwater levels than recharge, especially during high-flow periods. Dam operations locally altered groundwater flow paths and velocity. The aquifer is more prone to surface-water control in the upper reaches of the pools where stream stage fluctuations are more pronounced than in the lower reaches. This method could be a useful tool for quick assessment of induced infiltration rate and bank storage related to contamination investigations or well-field management.

  20. Impacts of Floods on Organic Carbon Concentrations in Alluvial Soils along Hydrological Gradients Using a Digital Elevation Model (DEM

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    Diane Saint-Laurent


    Full Text Available This study examines the spatial distribution of the organic carbon found in alluvial soils affected by successive floods. In flood zones, very little is known of the processes associated with the development of soils subjected to frequent flooding, in particular with respect to the accumulation of litter and organic carbon concentrations. The aim of this study is to better understand the distribution of organic carbon based on various hydrological gradients associated with flood recurrence. A digital elevation model was developed from LIDAR data to assess the microtopography of the site, and further delineate floodplains and no-flood zones. Various soil properties were considered in addition to organic carbon, such as pH, soil bulk density, litter, drainage, and topographic levels (elevation. The results show that the soils in the frequent-flood zones (FFz, recurrence of 0–20 years have significantly less total organic carbon than the soils in the no-flood zones (NFz and the moderate flood zones (MFz, 20–100 years. Average values obtained for the surface horizons (0–20 cm vary by 1.74% ± 0.85% (FFz, 3.34% ± 1.09% (MFz and 3.54% ± 1.77% (NFz, respectively. The absence of ground litter in the frequent flood zones helps decrease the input of organic matter in the surface horizons and progressively results in soil depletion.