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Sample records for alluvial soils

  1. Response spectra in alluvial soils

    International Nuclear Information System (INIS)

    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/v2. 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/v2 has been obtained which would nearly give the same magnification of the response. A design response spectra for alluvial soils has been recommended. (author)

  2. Evaluation of carbaryl sorption in alluvial soil

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    Naba Kumar Mondal

    2013-12-01

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

  3. Water transport in desert alluvial soil

    International Nuclear Information System (INIS)

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

  4. Microbial communities of alluvial soils in the Volga River delta

    Science.gov (United States)

    Sal'Nikova, N. A.; Polyanskaya, L. M.; Tyugai, Z. N.; Sal'Nikov, A. N.; Egorov, M. A.

    2009-01-01

    The number and biomass of the microbial community in the upper humus horizon (0-20 cm) were determined in the main types of alluvial soils (mucky gley, desertified soddy calcareous, hydrometamorphic dark-humus soils) in the Volga River delta. Fungal mycelium and alga cells predominate in the biomass of the microorganisms (35-50% and 30-47%, respectively). The proportion of prokaryotes in the microbial biomass of the alluvial soils amounts to 2-6%. No significant seasonal dynamics in the number and biomass of microorganisms were revealed in the alluvial soils. The share of carbon of the microbial biomass in the total carbon content of the soil organic matter is 1.4-2.3% in the spring. High coefficients of microbial mineralization and oligotrophy characterize the processes of organic matter decomposition in the alluvial soils of the mucky gley, desertified soddy calcareous, and hydrometamorphic dark humus soil types.

  5. Spatial variation of soil physical properties in adjacent alluvial and colluvial soils under Ustic moisture regime

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    M. Sağlam

    2011-04-01

    Full Text Available Soils vary spatially due to differences in soil management and soil formation factors. The soil spatial variability is an important determinant of efficiency of farm inputs and yield. This study was carried out to identify and compare spatial variation of some soil physical properties by geostatistics in alluvial and adjacent colluvial soils formed under ustic moisture regime at Gökhöyük State Farm (1750 ha, Amasya, Turkey. Seventy four soil samples were collected on a regular grid (500 × 500-m and additional 224 samples were collected on 28 500-m fine-transects, randomly superimposed between the nodes of grids. Semivariograms and corresponding kriging maps for soil texture, soil organic matter (SOM, bulk density (BD, saturated hydraulic conductivity (Ks, and available water content (AWC were prepared. Statistical analyses were conducted separately for colluvial and alluvial sites as well as whole area. The soils in alluvial site is rich in clay with high BD and SOM, and low in Ks and AWC; and the soils in colluvial site was designated as low in Ks, SOM, and AWC and high in BD. All variables, except SOM, showed a strong spatial dependency. In general, nugget, sill and range values of most of the studied soil variables decreased from alluvial site to colluvial site. When local (alluvial and colluvial sites separately and global (alluvial + colluvial kriged maps for BD, AWC, and soil textural separates, use of global semivariograms (one semivariogram for entire study area resulted in lost of some details in colluvial sites, suggesting that local semivariograms for alluvial and colluvial soils should be used in kriging predictions at the farm. The results had significant implications for water management as AWC was spatially associated to clay content in alluvial site and to clay and sand contents in colluvial site.

  6. Experimental determination of thermal properties of alluvial soil

    Science.gov (United States)

    Kulkarni, N. G.; Bhandarkar, U. V.; Puranik, B. P.; Rao, A. B.

    2016-02-01

    In the present work, thermal conductivity and specific heat of a particular type of alluvial soil used in brick making in a certain region of India (Karad, Maharashtra State) are experimentally determined for later use in the estimation of ground heat loss in clamp type kilns. These properties are determined simultaneously using the steady-state and the transient temperature data measured in the setup constructed for this purpose. Additionally, physical properties of the soil are experimentally determined for use with six models for the prediction of the thermal conductivity of soil. The predictions from the models are compared with the experimental data. A separate data fitting exercise revealed a small temperature dependence of the soil thermal conductivity on the soil mean temperature.

  7. Cobalt in alluvial Egyptian soils as affected by industrial activities

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Twenty-five surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted,moderately and highly polluted soils. The aim of this study was to evaluate total Co content in alluvial soils of Delta in Egypt using the delayed Neturen activation analysis technique (DNAA). The two prominent gamma ray lines at 1173.2 and 1332.5 keV was efficiently used for 60Co determination. Co content in non-polluted soil samples ranged between 13.12 to 23.20 ppm Co with an average of 18.16*4.38 ppm. Cobalt content in moderately polluted soils ranged between 26.5 to 30.00 ppm with an average of 28.3*1.3 ppm. The highest Co levels (ranged from 36 to 64.69 ppm with an average of 51.9*9.5); were observed in soil samples collected from, either highly polluted agricultural soils due to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  8. Dynamic analysis of a reactor building on alluvial soil

    International Nuclear Information System (INIS)

    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

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

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    SUCIATMIH

    2006-10-01

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

  10. Weeds of cereal stubble-fields on various soils in the Kielce region. P. III. Black, alluvial and rendzina soils

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    Maria Jędruszczak

    2013-12-01

    Full Text Available The weed flora growing stubble-fields area is determined by soil features. Weeds found in cereal stubble-fields on black soils formed from sands and loams, medium and haevy alluvial soils as well as brown and chernozem rendzina soils are presented in the paper. The 273 phytosociological records were worked out. They were collected from 87 stands situated in 76 localities of Kielce region. The results showed that species number and species composition were dependent on the soils (black. alluvial, rendzina. The existance of 118 (medium alluvial soil to 140 (brown rendzina soil weed species, including 73 common for all of the soils considered, was found there. Relatively high per cent (29-35 of them belonged to perennial weeds. From 22 (brown rendzina soil to 35 (heavy alluvial soil of species reached high constancy degrees (V-III. Stellaria media, Myosotis arvensis, Polygonum aviculare, Agropyron repens and Cirsium arvense predominated on the all of the soil examined. Among the weed flora registered, 25 species, recorded only on rendzina soils, were distinguishable for that soils.

  11. Contribution of granulometric fractions in phosphorus distribution in old alluvial soil

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    BROGOWSKI ZYGMUNT

    2014-12-01

    Full Text Available Phosphorus content and balance in granulometric fractions of old alluvial soil developed from alluvial deposits od Vistula River in middle Poland was studied. The distribution of phosphorus in particular granulometric fractions of the studied soil showed high quantitative variability vertically in the profile. This resulted from the layered structure of the Vistulian old alluvial formation developed throughout the Holocene. The contribution of grain fractions in phosphorus accumulation increased with a decrease in their diameter, and in certain fractions with a decrease in their quantitative state. Eluviation of phosphorus down the soil profile concerned in particular grain fraction <0.02 mm. Fractions with a larger diameters were not subject to the process. Phosphorus resources calculated from the grain fraction balance in the analysed soil amounted to an average of 1.7 kg·m2 to a depth of 200 cm.

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

    OpenAIRE

    Ahmet Sami Erol; Evgeny Shein; Evgeny Milanovskiy; Fariz Mikailsoy; Fatih Er; Sabit Ersahin

    2015-01-01

    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...

  13. Single application of Sewage Sludge to an Alluvial Agricultural Soil - impacts on Soil Quality

    Science.gov (United States)

    Suhadolc, M.; Graham, D. B.; Hagn, A.; Doerfler, U.; Schloter, M.; Schroll, R.; Munch, J. C.; Lobnik, F.

    2009-04-01

    Limited information exists on the effects of sewage sludge on soil quality with regard to their ability to maintain soil functions. We studied effects of sewage sludge amendment on soil chemical properties, microbial community structure and microbial degradation of the herbicide glyphosate. Three months soil column leaching experiment has been conducted using alluvial soils (Eutric Fluvisol) with no prior history of sludge application. The soil was loamy with pH 7,4 and organic matter content of 3,5%. Soil material in the upper 2 cm of columns was mixed with dehydrated sewage sludge which was applied in amounts corresponding to the standards governing the use of sewage sludge for agricultural land. Sludge did increase some nutrients (total N, NH4+, available P and K, organic carbon) and some heavy metals contents (Zn, Cu, Pb) in soil. However, upper limits for heavy metals in agricultural soils were not exceeded. Results of heavy metal availability in soil determined by sequential extraction will be also presented. Restriction fragment length polymorphism (RFLP) analyses of 16s/18s rDNA, using universal fungal and bacterial primers, revealed clear shifts in bacterial and fungal community structure in the upper 2 cm of soils after amendment. Fungal fingerprints showed greater short term effects of sewage sludge, whereas sewage sludge seems to have prolonged effects on soil bacteria. Furthermore, sewage sludge amendment significantly increased glyphosate degradation from 21.6±1% to 33.6±1% over a 2 months period. The most probable reasons for shifts in microbial community structure and increased degradation of glyphosate are beneficial alterations to the physical-chemical characteristics of the soil. Negative effects of potentially toxic substances present in the sewage sludge on soil microbial community functioning were not observed with the methods used in our study.

  14. Direct measurement and prediction of bulk density on alluvial soils of central Chile

    OpenAIRE

    Manuel Casanova; Elizabeth Tapia; Oscar Seguel; Osvaldo Salazar

    2016-01-01

    The significance of soil bulk density (ρ) as a key indicator of soil quality was examined in this study. Bulk density values obtained by direct methods (clod, cylinder, and excavation) with three sample sizes (small, medium, and large) were compared with those obtained by 10 published pedotransfer functions (PTFs) for two alluvial soils (a massive fine-textured Fluventic Haploxeroll and an aggregated, coarse-textured Fluventic Haploxerept) of central Chile. With the exception of small cylinde...

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

    OpenAIRE

    Diane Saint-Laurent; Julien St-Laurent; Marlies Hähni; Bassam Ghaleb; Camille Chapados

    2010-01-01

    Soils contaminated with hydrocarbons (C10–C50), polycyclic aromatic hydrocarbons (PAHs), and other contaminants (e.g., As, Cd, Cu, Pb) were recently discovered on the banks of the Saint-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, 20...

  16. Effect of N, Zn and Fe application on corn in alluvial soil

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    Michel Farah

    2013-12-01

    Full Text Available In a lysimeter experiment on alluvial loamy soil, the effect of an increasing level of urea with the addition of ZnSO4 or FeSO4 or both were tested on the yield and mineral composition of Zea mays plants. A response was found only to N application and it was of a diminishing return nature. The effect of the increasing N level in plants was reflected mostly in leaf composition and least in grain composition.

  17. Alluvial Deposits in Iowa

    Data.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-05-01

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

  19. Balloon and core sampling for determining bulk density of alluvial desert soil

    Science.gov (United States)

    Andraski, B.J.

    1991-01-01

    Samples were collected from major strata in the upper 5 m of an alluvial soil profile in the Amargosa Desert of southern Nevada to compare rubber-balloon and drive-core bulk-density measurement methods. Outside the range of fine-soil texture, where soil consistency was either very loose or very hard, the core method appeared to sample inaccurately, resulting in bulk-density values less than those determined by the balloon method. Under the severe sampling conditions encountered, large decreases in the relative accuracy of the core method were not directly related to rock-fragment content, but were related to extremes in the cohesiveness of the strata sampled. -from Author

  20. The affect of industrial activities on zinc in alluvial Egyptian soil determined using neutron activation analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thirty-two surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted,moderately and highly polluted soils.The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in Egypt by using the delayed neutron activation analysis technique (DNAA),in the irradiation facilities of the first Egyptian research reactor (ET-RR-1).The gamma-ray spectra were recorded with a hyper pure germanium detection system.The well resolved gamma-ray peak at 1116.0 kev was efficiently used for 65Zn content determination.Zn content in non-polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5 + 5.1 ppm.Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1 + 32.6 ppm.The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3 + 54.4 ppm,were observed in soil samples collected from,either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  1. Free Oxide Distribution in Poorly and Well Drained Soils Developed on Calcareous Alluvial Deposits

    Institute of Scientific and Technical Information of China (English)

    N. K. MOUSTAKAS; P. E. BAROUCHAS

    2003-01-01

    A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicarbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms,independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.

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

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    Rudy Erwiyono

    2005-08-01

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

  3. Specific physicochemical changes of the profile of cinnamonic forest and alluvial-meadow soils resulting from uranium mining

    International Nuclear Information System (INIS)

    Two soil variations situated on a uranium mining zone, i. e. cinnamonic forest and alluvial-meadow soils have been examined. It has been found that under the effect of uranium mining after the boring variant of geothechnological method, not only the morphological peculiarities of the soils under examination have been changed, but their physicochemical characteristics, as well. The soil changes are expressed in destruction of the organomineral complex, in radioactive contamination to a lower degree. Specific amelioration measures are proposed, aimed at reducing the negative results of uranium mining, and increasing fertility of soil under examination

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

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent

    2010-01-01

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

  5. Genotoxicity assessments of alluvial soil irrigated with wastewater from a pesticide manufacturing industry.

    Science.gov (United States)

    Anjum, Reshma; Krakat, Niclas

    2015-10-01

    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. PMID:26394621

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

    Directory of Open Access Journals (Sweden)

    Ahmet Sami Erol

    2015-04-01

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

  7. Geotechnical evaluation of the alluvial soils for urban land management zonation in Gharbiya governorate, Egypt

    Science.gov (United States)

    Masoud, Alaa A.

    2015-01-01

    Geological and geotechnical information from 534 borehole in-situ- and lab-based measured soil water conditions (Cl- and SO4-2 ion concentrations and depth to water), plasticity, unconfined compression, and consolidation parameters for alluvial clays have been analyzed. Multivariate factorial and clustering along with the geostatistical ordinary kriging techniques were used and evaluated in a Geographic Information systems (GIS) environment. The prime objective was to spatially model the geotechnical variability and to derive the loading factors along with recognition of the distinctive spatial geotechnical zones in terms of their likelihood of occurrence. Results have been, for the first time, presented for the alluvial soils of the Gharbiya governorate, Egypt with the principal management zones and their associated geotechnical risks in the main eight districts were characterized and evaluated for their favorability for construction. Plasticity charts indicated that the soils are inorganic cohesive highly plastic clays. Geotechnical parameters showed wide ranges evidenced by their large standard deviations. Principal five factors dominated with good correlations to the swelling potential (0.90), compression index (0.74), depth to water (-0.41), soil water salinity contents of Cl- (-0.64) and SO4-2 (-0.60), and the clay layer thickness (0.59), arranged respectively in their decreasing contribution to more than 70% of the total spatial variability. Three distinctive management zones were delineated with reference to construction favorability. The first zone showed the highest favorability for construction being characterized by lowest potentials to swelling and the Cl- and SO4-2 contents and hence corrosion. Characterized by a water level approaching the ground surface, largest Cl- and SO4-2 contents violating the severity limits, and largest swelling potential, the second zone attained the lowest construction favorability and therefore safety measures should be

  8. Spatial variability of organochlorine pesticides (DDTs and HCHs) in surface soils from the alluvial region of Beijing, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-yan; GAO Ru-tai; HUANG Yuan-fang; JIA Xiao-hong; JIANG Shu-ren

    2007-01-01

    The spatial variability in the concentrations of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis-(p-chlorophenyl) ethane (DDT) in surface soils was studied on the basis of the analysis of 131 soil samples collected from the surface layer (0-20 cm depth) of the alluvial region of Beijing, China. The concentrations of total HCHs (including α-, β-, γ-, and δ-isomers) and total DDTs (i ncluding p,p'-DDT, p,p'-DDD, p,p'-DDE, and o,p'-DDT) in the surface soils tested were in the range from nondetectable to 31.72 μg/kg dry soil, with a mean value of 0.91, and from nondetectable to 5910.83 μg/kg dry soil, with a mean value of 32.13,respectively. It was observed that concentrations of HCHs in all soil samples and concentrations of DDTs in 112 soil samples were much lower than the first grade (50 μg/kg) permitted in "Environment quality standard for soils in China (GB15618-1995)". This suggests that the pollution due to organochlorine pesticides was generally not significant in the farmland soils in the Beijing alluvial region. In this study, the spatial distribution and trend of HCHs and DDTs were analyzed using Geostatistical Analyst and GS+(513).Spatial distribution indicated how these pesticides had been applied in the past. Trend analysis showed that the concentrations of HCHs,DDTs, and their related metabolites followed an obvious distribution trend in the surface soils from the alluvial region of Beijing.

  9. Sources, lability and solubility of Pb in alluvial soils of the River Trent catchment, U.K

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, M., E-mail: mizqu@bgs.ac.uk; Tye, A.M.; Chenery, S.R.

    2012-09-01

    Alluvial soils are reservoirs of metal contaminants such as Pb that originate from many different sources and are integrated temporally and spatially through erosional and depositional processes. In this study the source, lability and solubility of Pb were examined in a range of alluvial soils from the middle and lower River Trent and its tributary the River Dove using Pb isotope apportionment and isotopic dilution. All samples were collected within 10 m of the river bank to represent the soil that is most likely to be remobilised during bank erosion. Paired samples were taken from the topsoil (0-15 cm) and subsoil (35-50 cm) to assess differences with depth. Lead concentrations in soil ranged from 43 to 1282 mg/kg. The lability of soil Pb varied between 9 and 56% of total metal concentration whilst Pb concentrations in pore water varied between 0.2 and 6.5 {mu}g/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 {sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 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

  10. Soil erosion history in central Tanzania based on OSL dating of colluvial and alluvial hillslope deposits

    Science.gov (United States)

    Eriksson, M. G.; Olley, J. M.; Payton, R. W.

    2000-12-01

    The Irangi Hills in Kondoa District, central Tanzania, are severely degraded by sheet, rill and gully erosion. Using recently developed optically stimulated luminescence (OSL) dating techniques, and a detailed study of the hillslope stratigraphy and soils, we have determined the sequence of events that gave rise to this highly degraded landscape. Two major colluvial deposits have been identified on the slopes. The oldest colluvium gave OSL deposition dates of 14,700±1600, 14,200±1500 and 11,400±1300 years ago. These dates coincide with the climatic change from dry to wet conditions, which took place during the Late Pleistocene. It is possible that the erosion and deposition of the old colluvium occurred as a response to this change. This phase of erosion and deposition was followed by a long phase of stability and pedogenetic alteration of the old colluvium. A phase of accelerated soil erosion began not later than 900 years ago, as indicated by a dated alluvial fan, the presence of which indicates that some deeper gullies already existed on upper pediment slopes at that time. The second, more recent colluvial deposit gave OSL dates of 460±40, 590±70 and 660±50 years. A major period of gully formation and incision, with subsequent fan development, occurred sometime between 600 and 300 years ago. The recent phase of erosion (livestock husbandry and iron smelting practices in the Irangi Hills.

  11. Moist-soil seed abundance in managed wetlands in the Mississippi Alluvial Valley

    Science.gov (United States)

    Kross, J.; Kaminski, R.M.; Reinecke, K.J.; Penny, E.J.; Pearse, A.T.

    2008-01-01

    Managed moist-soil units support early succession herbaceous vegetation that produces seeds, tubers, and other plant parts used by waterfowl in the Mississippi Alluvial Valley (MAV), USA. We conducted a stratified multi-stage sample survey on state and federal lands in the MAV of Arkansas, Louisiana, Mississippi, and Missouri during autumns 2002?2004 to generate a contemporary estimate of combined dry mass of seeds and tubers (herein seed abundance) in managed moist-soil units for use by the Lower Mississippi Valley Joint Venture (LMVJV) of the North American Waterfowl Management Plan. We also examined variation in mean seed abundance among moist-soil units in 2003 and 2004 in relation to management intensity (active or passive), soil pH and nutrient levels, proportional occurrence of plant life-forms (e.g., grass, flatsedge, and forb; vine; woody plants), and unit area. Estimates of mean seed abundance were similar in 2002 (X over bar = 537.1 kg/ha, SE = 100.1) and 2004 (X over bar = 555.2 kg/ha, SE = 105.2) but 35?40% less in 2003 (X over bar = 396.8 kg/ha, SE = 116.1). Averaged over years, seed abundance was 496.3 kg/ha (SE = 62.0; CV = 12.5%). Multiple regression analysis indicated seed abundance varied among moist-soil units inversely with proportional occurrence of woody vegetation and unit area and was greater in actively than passively managed units (R2adj = 0.37). Species of early succession grasses occurred more frequently in actively than passively managed units (P succession plants occurred more often in passively managed units (P < 0.02). We recommend the LMVJV consider 556 kg/ha as a measure of seed abundance for use in estimating carrying capacity in managed moist-soil units on public lands in the MAV. We recommend active management of moist-soil units to achieve maximum potential seed production and further research to determine recovery rates of seeds of various sizes from core samples and the relationship between seed abundance and unit area.

  12. RESPONSE OF SOYBEANS AND WHEAT TO PHOSPHORUS FERTILIZATION ON CALCAREOUS ALLUVIAL SOIL OF SAVA VALLEY AREA IN BOSNIA AND HERZEGOVINA

    OpenAIRE

    JOVIC, Jurica; Antunovic, Manda; Rastija, Mirta; Varga, Ivana

    2015-01-01

    The stationary field experiment of increasing rates of phosphorus (P) fertilization started in spring 2011 on calcareous alluvial soil of Posavian Canton in Federation of Bosnia and Herzegovina (B&H). The level of plant available P was found to be low by previous soil tests carried on with ammonium-lactate-method (7.06 pH in 1 M KCl; 4.17% organic matter; 3.79% CaCO3; 5.4 mg P2O5 in 100 g of soil). Five rates of P fertilizers (monoammonium phosphate: 13% N + 53 % P2O5) were applied as fol...

  13. Mobility and bio-availability of heavy metals in anthropogenically contaminated alluvial (deluvial) meadow soils (EUTRIC FLUVISOLS)

    Science.gov (United States)

    Dinev, Nikolai; Hristova, Mariana; Tzolova, Venera

    2015-04-01

    The total content of heavy metals is not sufficient to assess the pollution and the risk for environment as it does not provide information for the type and solubility of heavy metals' compounds in soils. The purpose was to study and determine the mobility of heavy metals in anthropogenically contaminated alluvial (delluvial) meadow soils spread around the non-ferrous plant near the town of Asenovgrad in view of risk assessment for environment pollution. Soil samples from monitoring network (1x1 km) was used. The sequential extraction procedure described by Zein and Brummer (1989) was applied. Results showed that the easily mobilizable cadmium compounds predominate in both contaminated and not contaminated soils. The stable form of copper (associated with silicate minerals, carbonates or amorphous and crystalline oxide compounds) predominates only in non polluted soils and reviles the risk of the environment contamination. Lead spreads and accumulates as highly soluble (mobile) compounds and between 72.3 and 99.6 percent of the total lead is bioavailable in soils. The procedure is very suitable for studying the mobility of technogenic lead and copper in alluvial soils with neutral medium reaction and in particular at the high levels of cadmium contamination. In soils with alkaline reaction - polluted and unpolluted the error of analysis increases for all studied elements.

  14. AN ANALYTICAL SOLUTION FOR THREE-DIMENSIONAL DIFFRACTION OF PLANE P-WAVES BY A HEMISPHERICAL ALLUVIAL VALLEY WITH SATURATED SOIL DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    Zhao Chenggang; Dong Jun; Gao Fuping

    2006-01-01

    An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion technique. Unlike previous studies, in which the saturated soil deposits were simulated with the single-phase elastic theory, in this paper, they are simulated with Biot's dynamic theory for saturated porous media, and the half space is assumed as a single-phase elastic medium. The effects of the dimensionless frequency, the incidence angle of P-wave and the porosity of soil deposits on the surface displacement magnifications of the hemispherical alluvial valley are investigated. Numerical results show that the existence of a saturated hemispherical alluvial valley has much influence on the surface displacement magnifications. It is more reasonable to simulate soil deposits with Biot's dynamic theory when evaluating the displacement responses of a hemispherical alluvial valley with an incidence of P-waves.

  15. The levels and composition of persistent organic pollutants in alluvial agriculture soils affected by flooding.

    Science.gov (United States)

    Maliszewska-Kordybach, Barbara; Smreczak, Bozena; Klimkowicz-Pawlas, Agnieszka

    2013-12-01

    The concentrations and composition of persistent organic pollutants (POPs) were determined in alluvial soils subjected to heavy flooding in a rural region of Poland. Soil samples (n = 30) were collected from the upper soil layer from a 70-km(2) area. Chemical determinations included basic physicochemical properties and the contents of polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polycyclic aromatic hydrocarbons (PAHs, 16 compounds). The median concentrations of Σ7PCB (PCB28 + PCB52 + PCB101 + PCB118 + PCB138 + PCB153 + PCB180), Σ3HCH (α-HCH + β-HCH + γ-HCH) and Σ3pp'(DDT + DDE + DDD) were 1.60 ± 1.03, 0.22 ± 0.13 and 25.18 ± 82.70 μg kg(-1), respectively. The median concentrations of the most abundant PAHs, phenanthrene, fluoranthene, pyrene, benzo[b]fluoranthene and benzo[a]pyrene were 50 ± 37, 38 ± 27, 29 ± 30, 45 ± 36 and 24 ± 22 μg kg(-1), respectively. Compared with elsewhere in the world, the overall level of contamination with POPs was low and similar to the levels in agricultural soils from neighbouring countries, except for benzo[a]pyrene and DDT. There was no evidence that flooding affected the levels of POPs in the studied soils. The patterns observed for PAHs and PCBs indicate that atmospheric deposition is the most important long-term source of these contaminants. DDTs were the dominant organochlorine pesticides (up to 99%), and the contribution of the parent pp' isomer was up to 50 % of the ΣDDT, which indicates the advantage of aged contamination. A high pp'DDE/pp'DDD ratio suggests the prevalence of aerobic transformations of parent DDT. Dominance of the γ isomer in the HCHs implies historical use of lindane in the area. The effect of soil properties on the POP concentrations was rather weak, although statistically significant links with the content of the <0.02-mm fraction, Ctotal or Ntotal were observed for some individual compounds in the PCB group. PMID:23877573

  16. Tracing recent environmental changes and pedogenesis using geochemistry and micromorphology of alluvial soils, Sabie-Sand River Basin, South Africa

    Science.gov (United States)

    Eze, Peter N.; Knight, Jasper; Evans, Mary

    2016-09-01

    Three pedons on the alluvial terraces of the Sabie-Sand River Basin within Kruger National Park, South Africa, were studied to improve our understanding of recent environmental changes, and assess degree of chemical weathering and pedogenesis in the area using geochemical and micromorphology proxies. Particle-size distributions were obtained using Malvern Mastersizer; soil geochemistry was determined by XRF and thin sections by routine laboratory procedures. The soils are predominantly sandy (> 94% sand in all samples). The mean phi-values of the soils had little variation suggesting that reworking of sediments upwards in individual profiles produced a more uniform pedogenesis rather than coming from different physical sources. Calcification is the dominant pedogenic process in these alluvial soils. The Chemical Index of Alteration (CIA) proved a more suitable index than Chemical Index of Weathering (CIW) for evaluating weathering in the terraces. The micromass and b-fabrics are mostly granostriated and partly brown mosaic speckled. MISECA values for the degree of soil development range from 4 to 9, which mean weakly to moderately-developed soils. Coarse secondary calcite nodules and coatings are responsible for cementation as observed in pedon 2, which suggests calcium carbonate precipitation from periodical flooding and evaporating groundwater events. The features and diagnostic properties of the soils on the alluvial terraces along the Sabie-Sand River provide evidence for land surface impacts of recent environmental changes in this internationally important conservation area. Precise dating of calcium carbonate precipitates is, however, needed to put the observed evidence into a wider geochronological perspective.

  17. Efficacy of indigenous soil microbes in arsenic mitigation from contaminated alluvial soil of India.

    Science.gov (United States)

    Majumder, Aparajita; Bhattacharyya, Kallol; Kole, S C; Ghosh, Sagarmoy

    2013-08-01

    Selected arsenic-volatilizing indigenous soil bacteria were isolated and their ability to form volatile arsenicals from toxic inorganic arsenic was assessed. Approximately 37 % of AsIII (under aerobic conditions) and 30 % AsV (under anaerobic conditions) were volatilized by new bacterial isolates in 3 days. In contrast to genetically modified organism, indigenous soil bacteria was capable of removing 16 % of arsenic from contaminated soil during 60 days incubation period while applied with a low-cost organic nutrient supplement (farm yard manure).

  18. WINTER FOOD AND WATERFOWL DYNAMICS IN MANAGED MOIST-SOIL WETLANDS IN THE MISSISSIPPI ALLUVIAL VALLEY

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Moistsoil wetlands that are seasonally flooded provide important habitats for waterfowl in the Mississippi Alluvial Valley MAV. These wetlands often contain tall...

  19. Spatial pattern of soil organic carbon in desert grasslands of the diluvial-alluvial plains of northern Qilian Mountains

    Institute of Scientific and Technical Information of China (English)

    Rong YANG; YongZhong SU; Min WANG; Tao WANG; Xiao YANG; GuiPing FAN; TianChang WU

    2014-01-01

    The soil properties in arid ecosystems are important determinants of vegetation distribution patterns. Soil organic carbon (SOC) content, which is closely related to soil types and the holding capacities of soil water and nutrients, exhibits complex variability in arid desert grasslands;thus, it is essentially an impact factor for the distri-bution pattern of desert grasslands. In the present study, an investigation was conducted to estimate the spatial pattern of SOC content in desert grasslands and the association with environmental factors in the diluvial-alluvial plains of northern Qilian Mountains. The results showed that the mean values of SOC ranged from 2.76 to 5.80 g/kg in the soil profiles, and decreased with soil depths. The coefficients of variation (CV) of the SOC were high (ranging from 48.83%to 94.67%), which indicated a strong spatial variability. SOC in the desert grasslands of the study re-gion presented a regular spatial distribution, which increased gradually from the northwest to the southeast. The SOC distribution had a pattern linked to elevation, which may be related to the gradient of climate conditions. Soil type and plant community significantly affected the SOC. The SOC had a significant positive relationship with soil moisture (P<0.05);whereas, it had a more significant negative relationship with the soil bulk density (BD) (P<0.01). However, a number of the variations in the SOC could be explained not by the environmental factors involved in this analysis, but rather other factors (such as grazing activity and landscape). The results provide important references for soil carbon storage estimation in this study region. In addition, the SOC association with environmental variables also provides a basis for a sustainable use of the limited grassland resources in the diluvial-alluvial plains of north-ern Qilian Mountains.

  20. Analysis and assessment on heavy metal sources in the coastal soils developed from alluvial deposits using multivariate statistical methods.

    Science.gov (United States)

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

    2009-05-30

    An investigation on heavy metal sources, i.e., Cu, Zn, Ni, Pb, Cr, and Cd in the coastal soils of Shanghai, China, was conducted using multivariate statistical methods (principal component analysis, clustering analysis, and correlation analysis). All the results of the multivariate analysis showed that: (i) Cu, Ni, Pb, and Cd had anthropogenic sources (e.g., overuse of chemical fertilizers and pesticides, industrial and municipal discharges, animal wastes, sewage irrigation, etc.); (ii) Zn and Cr were associated with parent materials and therefore had natural sources (e.g., the weathering process of parent materials and subsequent pedo-genesis due to the alluvial deposits). The effect of heavy metals in the soils was greatly affected by soil formation, atmospheric deposition, and human activities. These findings provided essential information on the possible sources of heavy metals, which would contribute to the monitoring and assessment process of agricultural soils in worldwide regions. PMID:18976857

  1. Analysis and assessment on heavy metal sources in the coastal soils developed from alluvial deposits using multivariate statistical methods.

    Science.gov (United States)

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

    2009-05-30

    An investigation on heavy metal sources, i.e., Cu, Zn, Ni, Pb, Cr, and Cd in the coastal soils of Shanghai, China, was conducted using multivariate statistical methods (principal component analysis, clustering analysis, and correlation analysis). All the results of the multivariate analysis showed that: (i) Cu, Ni, Pb, and Cd had anthropogenic sources (e.g., overuse of chemical fertilizers and pesticides, industrial and municipal discharges, animal wastes, sewage irrigation, etc.); (ii) Zn and Cr were associated with parent materials and therefore had natural sources (e.g., the weathering process of parent materials and subsequent pedo-genesis due to the alluvial deposits). The effect of heavy metals in the soils was greatly affected by soil formation, atmospheric deposition, and human activities. These findings provided essential information on the possible sources of heavy metals, which would contribute to the monitoring and assessment process of agricultural soils in worldwide regions.

  2. Alluvial Aquifer

    Data.gov (United States)

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

  3. Hydrodynamic characterization of a alluvial flow plain soil of Cajueiro in Tuparetama, Pernambuco State, Brazil - instantaneous profile method

    International Nuclear Information System (INIS)

    The knowledge of the hydraulic properties of soil K(Θ) and h(Θ) is required to better management of water transfers in the soils. Determining these properties is highly important in solving problems related to irrigation and drainage, and the transport of nutrients and salts. The experiment was carried out in an alluvial flow plain soil of Cajueiro Dam in Tuparetama, PE. By applying the Instantaneous Profile Method, it was possible to evaluate the hydraulic conductivity of the soil. A parcel of 3.5 m x 3.5 m was delimited for the experiment of internal drainage, and instrumented with an access tube for the neutron probe (water content measurement) and ten tensiometers (measurement of water potential in the soil). The soil profile of Cajueiro Dam is classified as varying from loamy sand (0-80 cm) to sandy (80-100 cm). As to its retention curves h(Θ) and hydraulic conductivity K(Θ), it is classified according to three horizons (0-20 cm), (30-50 cm) and (60-100 cm). In addition, the determination of the hydraulic properties K(Θ) and h(Θ) of the soil gives subsidies for a more efficient handling of this flood plain starting from simulations of soil water transfer processes in the horizons under study. (author)

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

    Directory of Open Access Journals (Sweden)

    Gary E Stinchcomb

    2014-08-01

    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

  5. Effect of Long-Term Fertilization on Organic Nitrogen Forms in a Calcareous Alluvial Soil on the North China Plain

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to illustrate the change of nitrogen (N) supply capacity after long-term application of manure and chemical fertilizer, as well as to properly manage soil fertility through fertilizer application under the soil-climatic conditions of the North China Plain, organic N forms were quantified in the topsoil with different manure and chemical fertilizer treatments in a 15-year fertilizer experiment in a Chinese calcareous alluvial soil Soil total N (TN) and various organic N forms were significantly influenced by long-term application of chemical fertilizer and manure. TN, total hydrolysable N, acid-insoluble N, amino acid N and ammonium N in the soil increased significantly (P < 0.05) with increasing manure and fertilizer N rates, but were not influenced by increasing P rates. Also, application of manure or N fertilizer or P fertilizer did not significantly influence either the quantity of amino sugar N or its proportion of TN. Application of manure significantly increased (P < 0.05) hydrolysable unknown N, but adding N or P did not. In addition, application of manure or N fertilizer or P fertilizer did not significantly influence the proportions of different soil organic N forms.

  6. Combined Chemical and Mineralogical Evidence for Heavy Metal Binding in Mining- and Smelting-Affected Alluvial Soils

    Institute of Scientific and Technical Information of China (English)

    A. VAN(E)K; V. ETTLER; T. GRYGAR; L. BOR(U)VKA; O. (S)EBEK; O. DR(A)BEK

    2008-01-01

    The binding of metallic contaminants (Pb, Cd, and Zn) and As on soil constituents was studied on four highly con-taminated alluvial soil profiles from the mining/smelting district of Pribram (Czech Republic) using a combination of mineralogical and chemical methods. Sequential extraction analysis (SEA) was supplemented by mineralogical investi-gation of both bulk samples and hcavy mineral fractions using X-ray diffraction analysis (XRD) and scanning electron microscopy with an energy dispersive X-ray spectrometer (SEM/EDS). The mineralogy of Fe and Mn oxides was studied by voltammetry of microparticles (VMP) and diffuse reflectance spectrometry (DRS). Zinc and Pb were predominantly were detected in soils by XRD and SEM/EDS. In contrast, Cd was the most mobile contaminant and was predominantly present in the exchangeable fraction. Arsenic was bound to the residual and reducible fractions (corresponding to Fe oxides or to unidentified Fe-Pb arsenates). SEM/EDS observations indicate the predominant affinity of Pb for Mn oxides,and to a lesser extent, for Fe oxidcs. Thus, a more suitable SEA procedure should be used for these mining-affected soils to distinguish between the contaminant fraction bound to Mn oxides and Fe oxides.

  7. Long-term fertilization of organic manure led to the succession of Bacillus community in an alluvial-aquic soil

    Science.gov (United States)

    Chen, Ruirui; Lin, Xiangui; Feng, Youzhi; Hu, Junli; Wang, Ruirui

    2014-05-01

    Long-term fertilization inevitably influences soil physic-chemical and biological properties. Our previous studies with a long-term fertilization experiment on an alluvial-aquic have revealed that specific Bacillus spp. was observed in organic manure-fertilized soils. The current study investigated the effects of long-term fertilization on the succession of Bacillus community in soils and their functions. The experiment included three fertilizer treatments: organic manure (OM), mineral fertilizers (NPK) and the control (without fertilizers). The results showed that long-term application of chemical fertilizers didn't increase the quantity of soil microbial population as much as organic fertilizers did, but it played an important role in maintaining the diversity and community structure of indigenous Bacilli. Correspondingly, long-term application of organic manure significantly increased the quantity while significantly decreased the diversity of Bacilli community. The ratio of Bacilli/bacteria was more constant in OM treatment than NPK indicating the stability of the response to long-term organic fertilizers. PCR-DGGE and clone library revealed the succession of Bacillus community after long-term application of organic manure and the dominant Bacillus spp occurred in the treatmen OM was Bacillus asahii. Our results also proved that Bacillus asahii was not derived from exogenous organic manure, but one of indigenous bacteria in the soil. Bacillus asahii was induced by the substrate after the application of organic manure, and gradually evolved into dominant Bacillus after 4 to 5 years. With an enzyme assay test of pure species and a soil incubation experiment, we came to a preliminary judgment, that the dominant Bacillus asahii didn't significantly influence the decomposition rate of cellulose and protein in the soil, but it promoted the decomposition of lipids, and could also improve the transformation process from fresh organic matter to humus. Applied organic

  8. Hyperaccumulator oilcake manure as an alternative for chelate-induced phytoremediation of heavy metals contaminated alluvial soils.

    Science.gov (United States)

    Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar

    2015-01-01

    The ability of hyperaccumulator oilcake manure as compared to chelates was investigated by growing Calendula officinalis L for phytoremediation of cadmium and lead contaminated alluvial soil. The combinatorial treatment T6 [2.5 g kg(-1) oilcake manure+5 mmol kg(-1) EDDS] caused maximum cadmium accumulation in root, shoot and flower up to 5.46, 4.74 and 1.37 mg kg(-1) and lead accumulation up to 16.11, 13.44 and 3.17 mg kg(-1), respectively at Naini dump site, Allahabad (S3). The treatment showed maximum remediation efficiency for Cd (RR=0.676%) and Pb (RR=0.202%) at Mumfordganj contaminated site (S2). However, the above parameters were also observed at par with the treatment T5 [2.5 g kg(-1) oilcake manure +2 g kg(-1) humic acid]. Applied EDDS altered chlorophyll-a, chlorophyll-b, and carotene contents of plants while application of oilcake manure enhanced their contents in plant by 3.73-8.65%, 5.81-17.65%, and 7.04-17.19%, respectively. The authors conclude that Calendula officinalis L has potential to be safely grown in moderately Cd and Pb-contaminated soils and application of hyperaccumulator oilcake manure boosts the photosynthetic pigments of the plant, leading to enhanced clean-up of the cadmium and lead-contaminated soils. Hence, the hyperaccumulator oilcake manure should be preferred over chelates for sustainable phytoremediation through soil-plant rhizospheric process. PMID:25397984

  9. Characterization and selection of biochar for an efficient retention of tricyclazole in a flooded alluvial paddy soil

    Energy Technology Data Exchange (ETDEWEB)

    García-Jaramillo, Manuel, E-mail: mgarcia@irnas.csic.es [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain); Cox, Lucía; Knicker, Heike E.; Cornejo, Juan [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain); Spokas, Kurt A. [United States Department of Agriculture–Agricultural Research Service, 1991 Upper Buford Circle, Saint Paul 55108, MN (United States); Hermosín, M.Carmen [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080 Seville (Spain)

    2015-04-09

    Highlights: • Biochar CEC was inversely correlated with HTT. • Enhanced aromaticity was associated to an improved biochar adsorption of tricyclazole. • The SSA of the biochars was inversely correlated with DOC contents. • Adsorption of tricyclazole was related to high SSA and low DOC content of biochars. • The use of AC and biochar in conjunction provides the slow release of tricyclazole. - Abstract: Biochars, from different organic residues, are increasingly proposed as soil amendments for their agronomic and environmental benefits. A systematic detection method that correlates biochar properties to their abilities to adsorb organic compounds is still lacking. Seven biochars obtained after pyrolysis at different temperatures and from different feedstock (alperujo compost, rice hull, and woody debris), were characterized and tested to reveal potential remedial forms for pesticide capture in flooded soils. Biochar properties were determined by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, specific surface area (SSA) assessment and scanning electron microscopy. In addition, dissolved organic matter (DOM) from these biochars was extracted and quantified in order to evaluate the effect on pesticide sorption. The biochars from alperujo compost presented very high affinity to the fungicide tricyclazole (55.9, 83.5, and 90.3% for B1, B4, and B5, respectively). This affinity was positively correlated with the pyrolysis temperature, the pH, the increased SSA of the biochars, and the enhanced aromaticity. Sorptive capacities were negatively related to DOM contents. The amendment with a mixture of compost and biochar endows the alluvial soil with high sorptive properties (from K{sub fads(soil)} = 9.26 to K{sub fads(mixture)} = 17.89) without impeding the slow release of tricyclazole.

  10. Soil proifle characteristics of high-productivity alluvial cambisols in the North China Plain

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-tao; LI Bao-guo; REN Tu-sheng

    2015-01-01

    The North China Plain (NCP) is one of major breadbaskets in China. Crop growth and grain yield differ signiifcantly with spatial variations of soil properties. This study aims to identify the key soil properties in relation to the grain yield for the winter wheat (Triticum aestivum L.)-maize (Zea mays L.) cropping system in a high-productivity farmland of the NCP. The ifeld trials were conducted in three ifelds with different grain yield levels in Tai’an City, Shandong Province, China, during the 2009–2012 period. Consistent ifeld management strategies were applied in the three ifelds. Fifty-one physical and chemical indicators of the soil proifle as related to grain yield were evaluated. An approximate maximum of 17.8%annual average grain yield difference was observed in the ifelds during the period of 2009–2012. The soil indicators were classiifed into three clusters with speciifc functions using cluster analysis, and three key indicators were extracted from each cluster to characterize the different soil properties of three ifelds. The ifrst cluster represented soil water retention capacity, and the key indicator was available soil water (ASW), which ranged from 153 to 187 mm in the 1.2 m proifle and was correlated positively with grain yield. The second cluster represented soil water conductivity, as measured by saturated hydraulic conductivity (Ks). The higher yield ifeld had a greater capacity to retain topsoil water for its lower Ks (1.9 cm d–1) in the 30–70 cm soil layer as compared to the lower yield ifeld. The third cluster represented nutrient storage and supply, as indicated by the ratio of nutrient content to silt+clay content of the top soil layer. The ratio of soil organic matter (OM), total nitrogen (TN), available P, exchangeable K+to silt+clay content in the 0–20 cm soil layer were 19.0 g kg–1, 1.6 g kg–1, 94.7 mg kg–1, 174.3 mg kg–1 in the higher yield ifeld, respectively, and correlated positively with the grain yield. By

  11. Mineral Occurrence, Translocation, and Weathering in Soils Developed on Four Types of Carbonate and Non-carbonate Alluvial Fan Deposits in Mojave Desert, Southeastern California

    Science.gov (United States)

    Deng, Y.; McDonald, E. V.

    2007-12-01

    Soil geomorphology and mineralogy can reveal important clues about Quaternary climate change and geochemical process occurring in desert soils. We investigated (1) the mineral transformation in desert soils developed on four types of alluvial fans (carbonate and non-carbonate) under the same conditions of climate and landscape evolution; and (2) the effects of age, parent materials, and eolian processes on the transformation and translocation of the minerals. Four types of alluvial-fan deposits along the Providence Mountains piedmonts, Mojave Desert, southeastern California, USA were studied: (1) carbonate rocks, primarily limestone and marble (LS), (2) fine-grained rhyodacite and rhyolitic tuff mixed with plutonic and carbonate rocks (VX), (3) fine- to coarse- grained mixed plutonic (PM) rocks, and (4) coarse-grained quartz monzonite (QM). These juxtaposed fan deposits are physically correlated in a small area (about 20 km by 15 km) and experienced the same climatic changes in the late Pleistocene and Holocene. The soils show characteristic mineral compositions of arid/semiarid soils: calcite is present in nearly all of the samples, and a few of the oldest soils contain gypsum and soluble salts. Parent material has profound influence on clay mineral composition of the soils: (1) talc were observed only in soils developed on the volcanic mixture fan deposits, and talc occurs in all horizons; (2) palygorskite occur mainly in the petrocalcic (Bkm) of old soils developed on the LS and VX fan deposits, indicating pedogenic origin; (3) chlorite was observed mainly in soils developed on VX fan deposits (all ages) and on some LS deposits, but it is absent in soils developed on PM and QM fan deposits; and (4) vermiculite was common throughout soils developed on plutonic rock fan deposits. These mineralogical differences suggest that minerals in the soils are primarily inherited from their parent materials and that mineral weathering in this area was weak. Except the

  12. Influence of Accompanying Anions on Potassium Retention and Leaching in Potato Growing Alluvial Soils

    Institute of Scientific and Technical Information of China (English)

    V.SHARMA; K.N.SHARMA

    2013-01-01

    A column study was carried out to assess the influence of accompanying anions on potassium (K) leaching at potato growing sites with different soil textures (sandy loam and clay loam) in northwestern India.Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg-1 through different sources having different accompanying anions (Cl-,SO42-,NO3-and H2PO4-).Maximum K was retained in the top 0-15 cm layer with a sharp decrease in K content occurring in 15-30 cm layer of the soil column.The trend was similar for both levels of applied K as well as frequency of leaching and soil type.The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam,while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg-1,indicating higher potential of clay rich soil to adsorb K.In general,the K leaching in presence of the accompanying anions followed the order of SO42-≤ H2PO42-< NO3-=Cl-.Highest 1 mol L-1 CH3COONH4-extractable K was retained when K was applied along with SO42-and H2PO4-anions,and the least was retained when accompanying anion was Cl-.The influence of anions was more pronounced in the light textured soil and at high amounts of K application.Higher levels of K application resulted in higher losses of K,especially in sandy loam soil as observed from the leachate concentration.Among the different K sources,the maximum amount of K leaching was noticed in the soil column amended with KCl.After four leachings,the maximum amount of K leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in Khanaura sandy loam at 60 mg K kg-1 of soil application through KCl.These concentrations were lower than the recommended guideline of the World Health Organisation (12.00 mg L-1).

  13. Laboratory Salinization of Brazilian Alluvial Soils and the Spectral Effects of Gypsum

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    Luis Clenio J. Moreira

    2014-03-01

    Full Text Available Irrigation-induced salinization is an important land degradation process that affects crop yield in the Brazilian semi-arid region, and gypsum has been used as a corrective measure for saline soils. Fluvent soil samples (180 were treated with increasing levels of salinization of NaCl, MgCl2 and CaCl2. The salinity was gauged using electrical conductivity (EC. Gypsum was added to one split of these samples before they were treated by the saline solutions. Laboratory reflectance spectra were measured at nadir under a controlled environment using a FieldSpec spectrometer, a 250-W halogen lamp and a Spectralon panel. Variations in spectral reflectance and brightness were evaluated using principal component analysis, as well as the continuum-removed absorption depths of major features at 1450, 1950, 1750 and 2200 nm for both the gypsum-treated (TG and non-treated (NTG air-dried soil samples as a function of EC. Pearson’s correlation coefficients of reflectance and the band depth with EC were also obtained to establish the relationships with salinity. Results showed that NTG samples presented a decrease in reflectance and brightness with increasing CaCl2 and MgCl2 salinization. The reverse was observed for NaCl. Gypsum increased the spectral reflectance of the soil. The best negative correlations between reflectance and EC were observed in the 1500–2400 nm range for CaCl2 and MgCl2, probably because these wavelengths are most affected by water absorption, as Ca and Mg are much more hygroscopic than Na. These decreased after chemical treatment with gypsum. The most prominent features were observed at 1450, 1950 and 1750 nm in salinized-soil spectra. The 2200-nm clay mineral absorption band depth was inversely correlated with salt concentration. From these features, only the 1750 and 2200 nm ones are within atmospheric absorption windows and can be more easily measured using hyperspectral sensors.

  14. Runoff and leaching of metolachlor from Mississippi River alluvial soil during seasons of average and below-average rainfall.

    Science.gov (United States)

    Southwick, Lloyd M; Appelboom, Timothy W; Fouss, James L

    2009-02-25

    The movement of the herbicide metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] via runoff and leaching from 0.21 ha plots planted to corn on Mississippi River alluvial soil (Commerce silt loam) was measured for a 6-year period, 1995-2000. The first three years received normal rainfall (30 year average); the second three years experienced reduced rainfall. The 4-month periods prior to application plus the following 4 months after application were characterized by 1039 +/- 148 mm of rainfall for 1995-1997 and by 674 +/- 108 mm for 1998-2000. During the normal rainfall years 216 +/- 150 mm of runoff occurred during the study seasons (4 months following herbicide application), accompanied by 76.9 +/- 38.9 mm of leachate. For the low-rainfall years these amounts were 16.2 +/- 18.2 mm of runoff (92% less than the normal years) and 45.1 +/- 25.5 mm of leachate (41% less than the normal seasons). Runoff of metolachlor during the normal-rainfall seasons was 4.5-6.1% of application, whereas leaching was 0.10-0.18%. For the below-normal periods, these losses were 0.07-0.37% of application in runoff and 0.22-0.27% in leachate. When averages over the three normal and the three less-than-normal seasons were taken, a 35% reduction in rainfall was characterized by a 97% reduction in runoff loss and a 71% increase in leachate loss of metolachlor on a percent of application basis. The data indicate an increase in preferential flow in the leaching movement of metolachlor from the surface soil layer during the reduced rainfall periods. Even with increased preferential flow through the soil during the below-average rainfall seasons, leachate loss (percent of application) of the herbicide remained below 0.3%. Compared to the average rainfall seasons of 1995-1997, the below-normal seasons of 1998-2000 were characterized by a 79% reduction in total runoff and leachate flow and by a 93% reduction in corresponding metolachlor movement via these routes

  15. Tritium tracer technique for study of water movement in alluvial soils

    International Nuclear Information System (INIS)

    Tritiated water injections at activity levels of 5 μCi/ml at depths of 30 cms were conducted before the onset of monsoon 1973 at three adjacent sites, one site being treated with NaCl at a location where the water table is sufficiently deep. After the monsoon season, soil samples were taken upto depths of 240 cms and analysed for tritium and moisture contents. The results show that the peak of the tritium activity has moved down from 15 to 110 cms below the injection line under NaCl treated plot and control conditions. Tritium data is used to work out the field water balance and results compared with the precipitation, run-off and evaporation data during the period of investigation. The pattern of moisture distribution and movement is discussed in relation to plant productivity. (author)

  16. Effect of dissolved organic matter derived from waste amendments on the mobility of inorganic arsenic (III) in the Egyptian alluvial soil

    Energy Technology Data Exchange (ETDEWEB)

    Rashad, Mohamed [Land and Water Technologies Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab, 21934 Alexandria (Egypt); Assaad, Faiz F. [Soils and Water Use Department, National Research Centre, Dokki, Cairo (Egypt); Shalaby, Elsayed A. [Environmental Studies Department, Institute of Graduate Studies and Research, Alexandria University (Egypt)

    2013-07-01

    Dissolved organic matter (DOM) is one of the decisive factors affecting pollutants mobility in soils receiving waste amendments. The aim of this study was to investigate the effects of DOM1 derived from agricultural solid waste (ASW) and DOM2 derived from municipal solid waste (MSW) on the mobility of inorganic arsenic (As) in two alluvial soils from the Nile River Delta. In column experiments, addition of DOM solutions significantly increased As concentration in the effluents. There was no significant difference between the two soils, the obtained results from soil2 columns revealed that DOM2 has stronger capability than DOM1 to facilitate As mobility. The pH of the studied soils is alkaline (8.1) which promoted the dissociation as well as deprotonation of DOM and as a consequence, humic substances in DOM become negatively charged organic anions, leading to their substantial competition with As for the adsorption sites on both soil surfaces. The results emphasized that in alkaline soils there is a risk of groundwater pollution in the long run by arsenic either naturally found in soil or originated at high soil pH when dissolved organic carbon (DOC) released from various organic amendments ASW and/or MSW and leached through soil profile.

  17. Effect of dissolved organic matter derived from waste amendments on the mobility of inorganic arsenic (III in the Egyptian alluvial soil

    Directory of Open Access Journals (Sweden)

    Mohamed Rashad, Faiz F. Assaad, Elsayed A. Shalaby

    2013-01-01

    Full Text Available Dissolved organic matter (DOM is one of the decisive factors affecting pollutants mobility in soils receiving waste amendments. The aim of this study was to investigate the effects of DOM1 derived from agricultural solid waste (ASW and DOM2 derived from municipal solid waste (MSW on the mobility of inorganic arsenic (As in two alluvial soils from the Nile River Delta. In column experiments, addition of DOM solutions significantly increased As concentration in the effluents. There was no significant difference between the two soils, the obtained results from soil2 columns revealed that DOM2 has stronger capability than DOM1 to facilitate As mobility. The pH of the studied soils is alkaline (8.1 which promoted the dissociation as well as deprotonation of DOM and as a consequence, humic substances in DOM become negatively charged organic anions, leading to their substantial competition with As for the adsorption sites on both soil surfaces. The results emphasized that in alkaline soils there is a risk of groundwater pollution in the long run by arsenic either naturally found in soil or originated at high soil pH when dissolved organic carbon (DOC released from various organic amendments ASW and/or MSW and leached through soil profile.

  18. Diversity of arbuscular mycorrhizal fungi in a chrono-sequence of alluvial and degraded soils due to mining processes in bajo cauca antioqueno, Colombia

    International Nuclear Information System (INIS)

    Arbuscular mycorrhizal fungi (AMF) presence and diversity were evaluated in undisturbed and disturbed soils form alluvial mining processes. The soils belong to the Tropic Fluvaquent, Typical Dystropept, and Typical Paleudult sub-groups which corresponded to Low, Middle and High terraces, respectively, of the Cauca river at Taraza town. AMF propagules were multiplied in Leonard jars under glass house conditions using sterile substrate, modified Hoagland's solution and different fractions of soil used as sources of inoculum, which corresponded to the size of the spores. A first assay was made in maize (Zea mays) which allowed mycorrhizal colonization in roots but not spore production. In a second assay, in kudzu (Pueraria phaseoloides) AMF spores and colonized roots were obtained with the treatments corresponding to propagules obtained from high terrace and disturbed soil. These treatments presented a significant effect on kudzu yield (P?0,001) respect to the other treatments. The AMF spores of undisturbed and disturbed soils showed low infective capacity. Nevertheless, propagules of AMF were multiplied in trap cultures, which produced spores of four morpho types. One of these was identified as G. microagregatum. The polymorphism obtained by RAPD's made possible the differentiation of these morpho types with the primer OPA2. Similitude above 38% was achieved using UPGMA system. The results indicated that four morpho types belong to the genus Glomus, but they possibly belong to different species. Our results are promissory in the differentiation of native strains of AMF with low number of spores collected from soil samples in rehabilitation processes, which normally is unknown.

  19. Dynamic Change of M ain Farmland Alluvial Soil Nutrients in Henan Province%施肥方式对土壤养分含量的影响

    Institute of Scientific and Technical Information of China (English)

    李艳梅; 袁天佑; 张传忠

    2014-01-01

    为了解河南省潮土区土壤养分含量的动态变化,长期(1998-2011年)监测了施肥与不施肥2种方式下的土壤养分含量动态变化,结果表明:习惯施肥处理土壤养分含量明显高于不施肥处理。习惯施肥处理的土壤有机质、全氮、碱解氮含量均呈缓慢上升趋势,2011年较1998年(基础年)分别增加了2.12 g/kg、0.0487 g/kg、3.79 mg/kg ;习惯施肥处理的土壤有效磷呈缓慢下降趋势,2011年较1998年降低5.12 mg/kg ;习惯施肥处理和不施肥处理的土壤速效钾含量均呈缓慢下降趋势;不施肥处理的土壤有机质、全氮、碱解氮、有效磷含量均呈缓慢下降趋势,分别较试验前下降了0.63 g/kg、0.1233 g/kg、32.68 mg/kg、12.32 mg/kg。由此可见,河南省潮土区土壤缺磷素和钾素较为突出。%In order to find out the dynamic change rule of soil fertility in Chao soil region of Henan province ,the long-term experiment of soil fertility was conducted in the alluvial soil of Henan province . The results showed that the soil nutrient content of conventional fertilization treatments was significantly higher than that of non-fertilization ones .The contents of soil organic matter ,total nitrogen and available nitrogen in long-term fertilization showed a slowly rising trend ,which increased by 2.12 g/kg , 0.048 7 g/kg and 3.79 mg/kg respectively in 2011 compared with those in 1998 .The content of soil available phosphorus in long-term fertilization showed a slowly downward trend ,which was 5.12 mg/kg lower in 2011 than in 1998 .The content of soil available potassium in long-term fertilization and non-fertilization treatments all showed a slowly downward trend .The contents of soil organic matter ,total nitrogen ,available nitrogen and available phosphorus in non-fertilization treatments all showed the slowly dow nw ard trends ,w hich decreased by 0.63 g/kg ,0.123 3 g/kg ,32.68 mg/kg and 12.32 mg/kg , respectively .T

  20. Remediation in Situ of Hydrocarbons by Combined Treatment in a Contaminated Alluvial Soil due to an Accidental Spill of LNAPL

    Directory of Open Access Journals (Sweden)

    Ettore Trulli

    2016-10-01

    Full Text Available Soil contamination represents an environmental issue which has become extremely important in the last decades due to the diffusion of industrial activities. Accidents during transport of dangerous materials and fuels may cause severe pollution. The present paper describes the criteria of the actions which were operated to remediate the potential risk and observed negative effects on groundwater and soil originating from an accidental spill of diesel fuel from a tank truck. With the aim to evaluate the quality of the involved environmental matrices in the “emergency” phase, in the following “safety” operation and during the remediation action, a specific survey on hydrocarbons, light and heavy, was carried out in the sand deposits soil. Elaboration of collected data allows us to observe the movement of pollutants in the unsaturated soil. The remediation action was finalized to improve the groundwater and soil quality. The former was treated by a so called “pump and treat” system coupled with air sparging. A train of three different technologies was applied to the unsaturated soil in a sequential process: soil vapour extraction, bioventing and enhanced bioremediation. Results showed that the application of sequential remediation treatments allowed us to obtain a state of quality in unsaturated soil and groundwater as required by Italian law.

  1. A comparative study on the decomposition of edible and non-edible oil cakes in the Gangetic alluvial soil of West Bengal.

    Science.gov (United States)

    Mondal, Sudeshna; Das, Ritwika; Das, Amal Chandra

    2014-08-01

    An experiment has been conducted under laboratory conditions to investigate the effect of decomposition of two edible oil cakes, viz. mustard cake (Brassica juncea L) and groundnut cake (Arachis hypogaea L), and two non-edible oil cakes, viz. mahua cake (Madhuca indica Gmel) and neem cake (Azadirachta indica Juss), at the rate of 5.0 t ha(-1) on the changes of microbial growth and activities in relation to transformations and availability of some plant nutrients in the Gangetic alluvial (Typic Haplustept) soil of West Bengal, India. Incorporation of oil cakes, in general, highly induced the proliferation of total bacteria, actinomycetes, and fungi, resulting in greater retention and availability of oxidizable C, N, and P in soil. As compared to untreated control, the highest stimulation of total bacteria and actinomycetes was recorded with mustard cake (111.9 and 84.3 %, respectively) followed by groundnut cake (50.5 and 52.4 %, respectively), while the fungal colonies were highly accentuated due to the incorporation of neem cake (102.8 %) in soil. The retention of oxidizable organic C was highly increased due to decomposition of non-edible oil cakes, more so under mahua cake (14.5 %), whereas edible oil cakes and groundnut cake in particular exerted maximum stimulation (16.7 %) towards the retention of total N in soil. A similar trend was recorded towards the accumulation of available mineral N in soil and this was more pronounced with mustard cake (45.6 %) for exchangeable NH4 (+) and with groundnut cake (63.9 %) for soluble NO3 (-). The highest retention of total P (46.9 %) was manifested by the soil when it was incorporated with neem cake followed by the edible oil cakes; while the available P was highly induced due to the addition of edible oil cakes, the highest being under groundnut cake (23.5 %) followed by mustard cake (19.6 %). PMID:24733437

  2. Micromorphology and stable-isotope geochemistry of historical pedogenic siderite formed in PAH-contaminated alluvial clay soils, Tennessee, U.S.A

    Science.gov (United States)

    Driese, S.G.; Ludvigson, Greg A.; Roberts, J.A.; Fowle, D.A.; Gonzalez, Luis A.; Smith, J.J.; Vulava, V.M.; McKay, L.D.

    2010-01-01

    Alluvial clay soil samples from six boreholes advanced to depths of 400-450 cm (top of limestone bedrock) from the Chattanooga Coke Plant (CCP) site were examined micromorphologically and geochemically in order to determine if pedogenic siderite (FeCO3) was present and whether siderite occurrence was related to organic contaminant distribution. Samples from shallow depths were generally more heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) than those at greater depth. The upper 1 m in most boreholes consisted of mixtures of anthropogenically remolded clay soil fill containing coal clinker, cinder grains, and limestone gravel; most layers of coarse fill were impregnated with creosote and coal tar. Most undisturbed soil (below 1 m depth) consisted of highly structured clays exhibiting fine subangular blocky ped structures, as well as redox-related features. Pedogenic siderite was abundant in the upper 2 m of most cores and in demonstrably historical (< 100 years old) soil matrices. Two morphologies were identified: (1) sphaerosiderite crystal spherulites ranging from 10 to 200 um in diameter, and (2) coccoid siderite comprising grape-like "clusters" of crystals 5-20 ??n in diameter. The siderite, formed in both macropores and within fine-grained clay matrices, indicates development of localized anaerobic, low-Eh conditions, possibly due to microbial degradation of organic contaminants. Stable-isotope compositions of the siderite have ??13C values spanning over 25%o (+7 to - 18%o VPDB) indicating fractionation of DIC by multiple microbial metabolic pathways, but with relatively constant ??18O values from (-4.8 ?? 0.66%o VPDB) defining a meteoric sphaerosiderite line (MSL). Calculated isotope equilibrium water ??18O values from pedogenic siderites at the CCP site are from 1 to 5 per mil lighter than the groundwater ??18O values that we estimate for the site. If confirmed by field studies in progress, this observation might call for a reevaluation of

  3. A comparative study on the decomposition of edible and non-edible oil cakes in the Gangetic alluvial soil of West Bengal.

    Science.gov (United States)

    Mondal, Sudeshna; Das, Ritwika; Das, Amal Chandra

    2014-08-01

    An experiment has been conducted under laboratory conditions to investigate the effect of decomposition of two edible oil cakes, viz. mustard cake (Brassica juncea L) and groundnut cake (Arachis hypogaea L), and two non-edible oil cakes, viz. mahua cake (Madhuca indica Gmel) and neem cake (Azadirachta indica Juss), at the rate of 5.0 t ha(-1) on the changes of microbial growth and activities in relation to transformations and availability of some plant nutrients in the Gangetic alluvial (Typic Haplustept) soil of West Bengal, India. Incorporation of oil cakes, in general, highly induced the proliferation of total bacteria, actinomycetes, and fungi, resulting in greater retention and availability of oxidizable C, N, and P in soil. As compared to untreated control, the highest stimulation of total bacteria and actinomycetes was recorded with mustard cake (111.9 and 84.3 %, respectively) followed by groundnut cake (50.5 and 52.4 %, respectively), while the fungal colonies were highly accentuated due to the incorporation of neem cake (102.8 %) in soil. The retention of oxidizable organic C was highly increased due to decomposition of non-edible oil cakes, more so under mahua cake (14.5 %), whereas edible oil cakes and groundnut cake in particular exerted maximum stimulation (16.7 %) towards the retention of total N in soil. A similar trend was recorded towards the accumulation of available mineral N in soil and this was more pronounced with mustard cake (45.6 %) for exchangeable NH4 (+) and with groundnut cake (63.9 %) for soluble NO3 (-). The highest retention of total P (46.9 %) was manifested by the soil when it was incorporated with neem cake followed by the edible oil cakes; while the available P was highly induced due to the addition of edible oil cakes, the highest being under groundnut cake (23.5 %) followed by mustard cake (19.6 %).

  4. Artificial soils from alluvial tin mining wastes in Malaysia--a study of soil chemistry following experimental treatments and the impact of mycorrhizal treatment on growth and foliar chemistry.

    Science.gov (United States)

    Tompkins, David S; Bakar, Baki B; Hill, Steve J

    2012-01-01

    For decades Malaysia was the world's largest producer of Sn, but now the vast open cast mining operations have left a legacy of some 100,000 ha of what is effectively wasteland, covered with a mosaic of tailings and lagoons. Few plants naturally recolonise these areas. The demand for such land for both urban expansion and agricultural use has presented an urgent need for better characterisation. This study reports on the formation of artificial soils from alluvial Sn mining waste with a focus on the effects of experimental treatments on soil chemistry. Soil organic matter, clay, and pH were manipulated in a controlled environment. Adding both clay tailings and peat enhanced the cation exchange capacity of sand tailings but also reduced the pH. The addition of peat reduced the extractable levels of some elements but increased the availability of Ca and Mg, thus proving beneficial. The use of clay tailings increased the levels of macro and micronutrients but also released Al, As, La, Pb and U. Additionally, the effects of soil mix and mycorrhizal treatments on growth and foliar chemistry were studied. Two plant species were selected: Panicum milicaeum and Pueraria phaseoloides. Different growth patterns were observed with respect to the additions of peat and clay. The results for mycorrhizal treatment (live inoculum or sterile carrier medium) are more complex, but both resulted in improved growth. The use of mycorrhizal fungi could greatly enhance rehabilitation efforts on sand tailings. PMID:22130476

  5. 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

    1964-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Abelardo A. A. Montenegro

    2006-03-01

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

  7. Variabilidade espacial da salinidade de um solo aluvial no semi-árido Paraibano Spatial variability of soil salinity in an alluvial soil of the semi-arid region of Paraíba state

    Directory of Open Access Journals (Sweden)

    Lázaro Costa de Souza

    2000-04-01

    Full Text Available O objetivo deste trabalho foi estudar a variabilidade espacial do pH da pasta de saturação (pHps, condutividade elétrica do extrato de saturação (CEes e porcentagem de sódio trocável (PST de um solo aluvial afetado por sais. Foram coletadas amostras de solo nas camadas 0-20, 20-40 e 40-60 cm, numa área do Projeto de Irrigação Capoeira, localizado em São José do Bonfim, Estado da Paraíba, utilizando-se um esquema sistemático de amostragem numa malha regular de 10 x 15 m. Os dados foram analisados através da estatística descritiva e geoestatística. Verificou-se baixa variabilidade para o pHps (CV 60 %. Modelos esférico e gaussiano foram ajustados aos semivariogramas das variáveis que apresentaram estrutura de dependência espacial, tendo-se obtido alcances variando de 20 a 40 m. Os mapas de isolinhas da combinação da CEes e PST permitiram visualizar o padrão de variabilidade da salinidade e sodicidade, constituindo-se em uma ferramenta para a definição de estratégias de manejo edáfico e recuperação da área afetada.The objective of this work was to study the spatial variability of pH of saturation paste (pHsp, the electrical conductivity of saturation extract (ECe and the exchangeable sodium percentage (ESP in an alluvial salt affected soil. Soil samples were collected in 0 - 20, 20 - 40 and 40 - 60 cm depths, in an area of the Irrigation Project of Capoeira, located in São José do Bonfim - Paraíba (Brazil, following a systematic scheme of sampling in a 10 x 15 m mesh. The data were analyzed through the descriptive statistics and geostatistics. Low variability was observed for the pHsp (CV 60%. Spherical and gaussian models were adjusted to the experimental semivariograms of the variables that presented a spatial dependence structure. Structures of spatial dependence, with range varying from 20 to 40 m were observed. The maps of isohypsas of the combination of ECe and ESP allowed the visualization of the pattern of

  8. Effects of Long-term Located Fertilization on the Physiochemical Properties of Non-calcareous Alluvial Soil%长期定位施肥对无石灰性潮土理化性质的影响

    Institute of Scientific and Technical Information of China (English)

    赵秀芬; 李俊良

    2009-01-01

    [目的]为改善土壤理化性质和促进农业可持续发展提供理论依据.[方法]通过田间试验研究长期定位不同施肥对无石灰性潮土理化性质的影响.[结果]单施有机肥处理的土壤含水量最高,CK的土壤含水量最低.施用有机肥处理的土壤容重较小,CK和无机肥处理的土壤容重较大.施用有机肥处理的土壤孔隙度显著高于不施有机肥处理和CK.施用有机肥、化肥处理和CK的土壤有机质含量分别约为原始土样的7.5、2.8和2.3倍.施用有机肥处理的土壤pH值提高了0.62,施用无机肥处理的土壤pH值降低.长期定位不同施肥对土壤速效养分氮磷钾含量的影响为:有机-无机肥料配施>单施大量有机肥>无机肥配施>单施氮肥>不施肥.[结论]有机-无机肥料配施能有效改善无石灰性潮土的理化性质.%[Objective]The purpose of the research was to supply theoretical basis for improving the physiochemical properties of soil and promoting agricultural sustainable development. [Method]The effects of applying different fertilizers in long-term located fertilization on the physiochemical properties of non-calcareous alluvial soil were researched through field experiment. [Result]The soil water content in the treatment with organic fertilizer only was highest and that in CK was lowest. The soil buil density in the treatment with organic fertilizer was smaller and that in CK and the treatment with inorganic fertilizer were bigger. The soil porosity in the treatment with organic fertilizer was significantly higher than that in the treatment without organic fertilizer and CK. The soil organic matter contents in the treatments with organic fertilizer, chemical fertilizer and CK were about 7.5, 2.8 and 2.3 times of that in the original soil samples resp. The soil pH value in the treatment with organic fertilizer was enhanced by 0.62 and that in the treatment with inorganic fertilizer was decreased. The effects of

  9. The toxicity assessment of chromium in Beijing Kaleyard Alluvial Soil-Pakchoi System%北京菜园潮土-小白菜系统中铬的毒性评价

    Institute of Scientific and Technical Information of China (English)

    戴宇; 杨重法; 郑袁明; 季天委

    2009-01-01

    In this study, pot experiments using the Beijing alluvial soils were conducted to examine the effects of hexavalent chromium (Cr), concentrations ranging from 0 to 50 mg · kg-1 , on the biomass and Cr concentrations of pakchoi (Brassica chinensis L. ), soil mi-crobial biomass carbon, soil microbial biomass nitrogen and soil microbial respiration. The results showed that in the high Cr concentration treatments (with addition 25≥ mg · kg~(-1)), the Cr concentrations in pakchoi leaves increased significantly compared with the ontrol treatment (P<0.01). The total Cr concentrations in pakchoi roots were much greater than those in leaves. Compared with the control treatment, the biomass of pakchoi leaf increased significantly in the 1 mg · kg~(-1) Cr treatment, while its biomass decreased significantly in the high Cr concentration treatments (≥10 mg · kg~(-1)) (P<0.01) and the highest decreasing extent was up to 78.2%. In the 50 mg·kg~(-1) Cr treatment, the soil mi-crobial biomass carbon, microbial biomass nitrogen and respiration rate were significantly lower than these indicators of control treatments. The biomass and total Cr concentration of pakchoi leaves, soil microbial biomass carbon, soil microbial biomass nitrogen and soil microbial respiration rate could all be sensitively served as biological indicators to reflect the pollution extent of soil Cr. By using these indicators and the corresponding total Cr concentrations of soil, we could obtain the fitting equations. Based on the conceptions of crop yield reduction, food safety and ecological dose, we could calculate the Cr mild pollu-tion critical concentration of Beijing alluvial soil ED_10 (70.8 mg · kg~(-1)) and the Cr moder-ate pollution critical concentration of Beijing alluvial soil ED_50 (111.6 mg · kg~(-1) ). The re-sults would be helpful to the revision and rebuilding of soil environmental criteria.%通过盆栽实验,以北京潮土为供试材料,研究了土壤中添加0~50 mg·kg~(-1

  10. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  11. Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: a potential source of geogenic Cr(VI) to groundwater

    Science.gov (United States)

    Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

    2011-01-01

    Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization’s maximum contaminant level for drinking water (50 μg L−1) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 μg L−1. To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to ~1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged from 0 to 42 μg kg−1, representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a

  12. Gypsum-saturated water to reclaim alluvial saline sodic and sodic soils Água saturada com gesso na recuperação de solos aluviais salino-sódicos e sódicos

    Directory of Open Access Journals (Sweden)

    Karien Rodrigues da Silveira

    2008-02-01

    Full Text Available Inadequate management of soil and irrigation water contribute to soil degradation, particularly in the alluvial areas of Northeast Brazil, where salinity and sodicity are already common features. This study evaluates the effects of the addition of gypsum in the irrigation water on physical and chemical properties of soils with different levels of salinity and sodicity. Samples were collected at the Custódia irrigation area of Brazil, predominantly covered by alluvial soils. Leaching tests using simulated irrigation water classified as C3S1, and gypsum-saturated irrigation water were carried out in soil columns of 20 and 50 cm depth. Soil leaching with gypsum saturated water (T2 resulted in an increase in the amounts of exchangeable calcium and potassium, and in a decrease of soil pH, in relation to the original soil (T0, with significant statistical differences to the treatment using only water (T1. There was a reduction in the electrical conductivity, exchangeable sodium and exchangeable sodium percentage in both treatments (T1 and T2, with treatment T2 being more effective in the leaching of soil sodium. No changes of electrical conductivity, calcium and pH in depth were observed, but the 20 - 50 cm layer presented higher amounts of magnesium, sodium and exchangeable sodium percentage. Gypsum saturated water improved the hydraulic conductivity in both layers. The use of gypsum in the irrigation water improved soil physical and chemical properties and should be considered as an alternative in the process of reclamation of saline-sodic and sodic soils in Northeast Brazil.O manejo inadequado do solo e da água de irrigação contribui para a degradação dos solos, particularmente nas áreas aluviais do Nordeste do Brasil, onde a salinidade e a sodicidade são características comumente observadas. Avaliaram-se os efeitos da adição do gesso na água de irrigação, sobre as propriedades físicas e químicas de solos com diferentes níveis de

  13. Detectability of minerals on desert alluvial fans using reflectance spectra

    Science.gov (United States)

    Shipman, Hugh; Adams, John B.

    1987-01-01

    The visible and near-infrared reflectance spectra of soil samples collected from desert alluvial and colluvial surfaces in the Cuprite mining district, Nevada, were analyzed. These surfaces are downslope from hydrothermally altered volcanic rocks that contain spectrally characteristic minerals such as alunite and kaolinite. Coarse fractions of the soils on the alluvial fans are mineralogically variable and express the upslope lithologies; fine fractions are remarkably similar mineralogically and spectrally in all samples because of dilution of local mineral components by regionally derived windblown dust. Theoretical models for spectral mixing and for particle-size effects were used to model the observed spectral variations. Diagnostic mineral absorption bands in the spectra of fan materials were enhanced by computationally removing the spectrum of the homogeneous fine-soil component. Results show that spectral mixing models are useful for analyzing data with high spectral resolution obtained by field and aircraft spectrometers.

  14. Variabilidade espacial de atributos físicos em solos de vale aluvial no semiárido de Pernambuco Spatial variability of physical attributes of soil in alluvial valley of semiarid region of Pernambuco state

    Directory of Open Access Journals (Sweden)

    Karla S. Santos

    2012-08-01

    Full Text Available As características físicas e hidráulicas do solo se constituem em condicionantes a planos de manejo agrícola. Objetivou-se avaliar atributos físicos em solos de um vale aluvial e sua variabilidade, no semiárido do Estado de Pernambuco, na bacia hidrográfica do Rio Ipanema. Técnicas estatísticas e geoestatísticas foram utilizadas a fim de se investigar o grau de dependência e a variabilidade espacial dos atributos, em lotes de agricultura familiar. O coeficiente de variação apresentou-se alto para a condutividade hidráulica do solo e médio para a resistência à penetração de raízes e para as frações granulométricas areia, argila e silte. Tal coeficiente foi baixo para a densidade do solo e de partículas e porosidade total. Foram investigadas as estruturas de dependência espacial para as variáveis estudadas, encontrando-se alcances variando de 135 m para a condutividade hidráulica a 465 m para o conteúdo de silte. Mapa de isolinhas foi elaborado por krigagem representando a variabilidade espacial da condutividade hidráulica, com moderado grau de dependência espacial. As frações granulométricas areia total e silte (% também apresentaram grau de dependência espacial moderado. A resistência à penetração, densidade do solo e de partículas, não apresentaram dependência espacial na escala de investigação adotada. Foi possível identificar regiões de maior aptidão agrícola verificando-se, através do mapeamento, que os solos francos tendem a apresentar elevada resistência à penetração e baixa condutividade hidráulica.Soil physical and hydraulic characteristics are relevant for agricultural management, particularly at irrigation districts. The objective of this study was to evaluate the spatial variability of physical attributes of soil in an alluvial valley in the semiarid region of Pernambuco State, at the Ipanema River Watershed. Statistical techniques and geostatistics were applied to observe the

  15. Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

    Science.gov (United States)

    Twilley, R.

    2014-12-01

    Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only

  16. Dynamic of phosphorus accumulation in anthropogenic- alluvial soil of Yellow River irrigation area in Ningxia%宁夏引黄灌区灌淤土壤磷累积状况及磷肥肥效研究

    Institute of Scientific and Technical Information of China (English)

    王芳; 李友宏; 赵天成; 陈晨; 洪瑜; 刘汝亮

    2011-01-01

    宁夏第二次土壤普查结果表明,灌淤耕地速效磷含量明显提高,平均含量由1985年的16.3 mg/kg增加到现在28.04 mg/kg.吴忠市利通区东塔乡国家农业科技示范园区磷肥肥效试验研究表明:土壤速效磷含量在50~60 mg/kg高水平下,小麦套玉米施磷效果较低,小麦玉米总产量肥料函数效应达显著水平.施P2O5最大量114kg/hm2,产量最大为12 245 kg/hm2,肥科农学效率为4.43 kg/kg P2O,肥料农学效率随施肥量增加而降低,施有机肥(45 t/hm2)条件下施磷无效;水稻施磷也无效.但为保持土壤养分平衡,小麦套种玉米、水稻分别需施P2O5 89、107kg/hm2.土壤含磷中下等水平,水稻施磷效果显著,特别是配施氮钾肥处理的磷肥农学效率最高达26.6 kg/kgP2O5.P2O5施量达到135 kg/hm2时则减产.当施P2O5量>64 kg/hm2时产量随施磷量增加而降低,在此施磷量下产量最高为10 158 kg/hm2,磷肥农学效率23.3 kg/kg P2O5.%The Second Soil Census of Ningxia showed that the content of available phosphorus (FRP) in anthro-pogenic-alluvial soil of irrigation areas was improved obviously, and the average content of FRP was increased from 16.3 mg/kg to 28.0 mg/kg in 1985. Fertilization experiments in Dongta village of Wuzhong showed that application of phosphate fertilizer did not affect the crops in the soil containing 50 ~ 60 mg/kg FRP. The more fertilizer used, the lower fertilizer efficiency produced. The maximum fertilizer efficiency was of 4.4 kg. It had little impact on crop yield when applying P2O5 combined with organic manure. However, P2O5 should be applied with the amount of 90 kg/hm2 to keep the soil nutrient in balance. Though there was a negative effect of phosphate fertilizer applied in paddy fields, P2O5 should be applied with an amount of 92 kg/hm2 to keep the paddy soil available phosphorus in balance. Reasonable application amount of P2O5 in paddy field was better when the soil phosphorus content was in middle or

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

    Directory of Open Access Journals (Sweden)

    Rodolfo Oscar Zappino

    2010-07-01

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

  18. Hydrodynamic characterization of an alluvial soil for the Cajueiro Reservoir in Tuparetama-PE (Brazil), by using the internal drainage method; Caracterizacao hidrodinamica de um solo aluvial do Acude Cajueiro em Tuparetama-PE utilizando-se o metodo da drenagem interna

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Aviani Maria Bezerra

    2000-10-01

    The determination of the hydraulic properties of an alluvial soil in Cajueiro reservoir has been carried out in two experimental plots of 3.5 m x 3.5 m, installed in the opposite banks of the brook in which is located the dam, (Tuparetama Country, Pernambuco). For the determination of the hydraulic conductivity as a function of the soil water volumetric content K({theta}), the internal driainage method proposed by Hillel et al. (1972) has been applied. The soil-water retention curves h ({theta}) have been determined through the experimental data of volumetric water content and pressure obtained in field experiments. The h ({theta}) and K ({theta}) curves have been fitted to van Genuchten's closed - form equations (1980), using the Burdine's model, and Brooks and Corey's model, respectively. The volumetric water content, matric potential, and total water content estimates have been fitted to two analytical functions: one being composed by the addition of three exponentials terms the other composed and by representation the reverse of the power functions. The latter has been preferred due to its smoother representation between the fast and the slow its drainage phases. Considering the hydraulic behavior, three different layers have been identified in the soil profiles of the two experimental parcels A2 and B4 in the alluvial soil Cajueiro reservoir. The second layer of the soil profile in parcel A2 turned out the more pemeable than the other two layers. As to the soil profile in parcel B4, the first layer turned out more conductive than the other layers. However, the biggest volumetric water content variations were due to the differences found in the texture and structure of the soil profiles under study. The hydrodynamic characterization of the two soil profiles, A2 and B4, brings significant elements for the simulation of scenarios related to the soil of water transport processes. It is of particular importance the study of scenarios related to the

  19. Seismic responses of a hemispherical alluvial valley to SV Waves: a three-dimensional analytical approximation

    Institute of Scientific and Technical Information of China (English)

    Chenggang Zhao; Jun Dong; Fuping Gao; D.-S.Jeng

    2006-01-01

    An analytical solution to the three-dimensional scattering and diffraction of plane SV-waves by a saturated hemispherical alluvial valley in elastic halfspace is obtained by using Fourier-Bessel series expansion technique.The hemispherical alluvial valley with saturated soil deposits is simulated with Biot's dynamic theory for saturated porous media.The following conclusions based on numerical results can be drawn:(1) there are a significant differences in the seismic response simulation between the previous single-phase models and the present two-phase model;(2)the normalized displacements on the free surface of the alluvial valley depend mainly on the incident wave angles,the dimensionless frequency of the incident SV waves and the porosity of sediments;(3)with the increase of the incident angle,the displacement distributions become more complicated,and the displacements on the free surface of the alluvial valley increase as the porosity of sediments increases.

  20. Calibração de um modelo de umidade para um solo aluvial sem cobertura vegetal Calibration of a soil moisture model for an alluvial soil without vegetable cover

    Directory of Open Access Journals (Sweden)

    Eduardo C. B. de Araújo

    2001-12-01

    Full Text Available O presente trabalho foi conduzido na região semi-árida em solo aluvial eutrófico, em área irrigada da Fazenda Experimental Vale do Curu, pertencente à Universidade Federal do Ceará. O experimento se desenvolveu no período de 4/10/99 a 10/3/00, mantendo-se o solo sem vegetação, com objetivo de calibrar o modelo de umidade do solo para atividades agrícolas (MUSAG e determinar os parâmetros associados às funções que compõem o modelo (infiltração, percolação e evaporação. A calibração consistiu em se medir a umidade no solo, na profundidade de 0 a 0,30 m, com uma sonda de nêutrons, e comparar essas medidas com a umidade no solo estimada pelo modelo parametrizado. O MUSAG permitiu valores estimados de armazenamento hídrico, estatisticamente não diferentes dos valores determinados pela sonda de nêutrons para a profundidade de 0 - 0,30 m. O modelo apresentou resultado menos satisfatório para estimativa da umidade em períodos com maior freqüência de precipitação, seguindo a tendência dos valores observados, porém subestimando-os.This work was carried out at the Experimental Farm of the Universidade Federal do Ceará, Curu River Valley, in the State of Ceará, Brazil, from October 4, 1999 to March 10, 2000, to calibrate, under field conditions, the so called soil moisture model for agricultural activities (MUSAG determining the parameters associated to the model functions (infiltration, percolation and evaporation.The measurements of soil water storage were done with a neutron probe, and compared with that predicted by the model. The MUSAG provided values of storage water, statistically not different from the values determined by the neutron probe for the depth of 0 - 0,30 m. The model did not provide reasonable estimates of the soil moisture during periods with larger precipitation frequency, however, the predictions followed the tendency of the observed values, but underestimating them.

  1. REVIEW OF REGIME THEORY OF ALLUVIAL CHANNELS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    One of the most important problems in river engineering is to determine a stable cross section geomenry and slope for an alluvial channel. This has been the subject of considerable research for about a century and continues to be of great practical interest. Lgnoring plan geometry, an alluvi-al channel can adjust its slope, depth and width, to develop a dynamic stable condition in which it can transport a certain a-mount of water and sediment. The brief history of regime the-ory and its new development are reviewed in this paper.

  2. Alluvial Boundary of California's Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the extent of the alluvial deposits in the Central Valley of California and encompasses the contiguous Sacramento, San Joaquin, and...

  3. Silicate weathering in the Ganges alluvial plain

    Science.gov (United States)

    Frings, Patrick J.; Clymans, Wim; Fontorbe, Guillaume; Gray, William; Chakrapani, Govind J.; Conley, Daniel J.; De La Rocha, Christina

    2015-10-01

    The Ganges is one of the world's largest rivers and lies at the heart of a body of literature that investigates the interaction between mountain orogeny, weathering and global climate change. Three regions can be recognised in the Ganges basin, with the Himalayan orogeny to the north and the plateaus of peninsular India to the south together delimiting the Ganges alluvial plain. Despite constituting approximately 80% of the basin, weathering processes in the peninsula and alluvial plain have received little attention. Here we present an analysis of 51 water samples along a transect of the alluvial plain, including all major tributaries. We focus on the geochemistry of silicon and its isotopes. Area normalised dissolved Si yields are approximately twice as high in rivers of Himalaya origin than the plain and peninsular tributaries (82, 51 and 32 kmol SiO2 km-2 yr-1, respectively). Such dissolved Si fluxes are not widely used as weathering rate indicators because a large but variable fraction of the DSi mobilised during the initial weathering process is retained in secondary clay minerals. However, the silicon isotopic composition of dissolved Si (expressed as δ30Si) varies from + 0.8 ‰ in the Ganges mainstem at the Himalaya front to + 3.0 ‰ in alluvial plain streams and appears to be controlled by weathering congruency, i.e. by the degree of incorporation of Si into secondary phases. The higher δ30Si values therefore reflect decreasing weathering congruency in the lowland river catchments. This is exploited to quantify the degree of removal using a Rayleigh isotope mass balance model, and consequently derive initial silica mobilisation rates of 200, 150 and 107 kmol SiO2 km-2 yr-1, for the Himalaya, peninsular India and the alluvial plain, respectively. Because the non-Himalayan regions dominate the catchment area, the majority of initial silica mobilisation from primary minerals occurs in the alluvial plain and peninsular catchment (41% and 34%, respectively).

  4. Morphodynamic equilibrium of alluvial estuaries

    Science.gov (United States)

    Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

    2014-05-01

    The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final

  5. Alluvial Fan Study Submission for UMATILLA COUNTY, OREGON

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Alluvial fan study data as defined in FEMA Guidelines and Specifications, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping

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

    DEFF Research Database (Denmark)

    Jain, M.; Tandon, S.K.

    2003-01-01

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

  7. Variation in erosion/deposition rates over the last 50 years on alluvial fan surfaces of L. Pleistocene- Mid Holocene age, estimations using 137Cs soil profile data, Amargosa Valley, Nevada.

    Science.gov (United States)

    Harrington, C.; Kelley, R.; Ebert, T.; Delong, S.; Cline, M.; Pelletier, J.; Whitney, J.

    2005-12-01

    Variations in erosion and deposition for the last fifty years (based on estimates from 137Cs profiles) on surfaces (Late Pleistocene to Late Holocene in age) making up the Fortymile Wash alluvial fan south of Yucca Mountain, is a function of surface age and of desert pavement development or absence. For purposes of comparing erosion and deposition, the surfaces can be examined as three groups: (1) Late Pleistocene surfaces possess areas of desert pavement development with thin Av or sandy A horizons, formed by the trapping capabilities of the pavements. These zones of deposition are complemented by coppice dune formation on similar parts of the surface. Areas on the surface where no pavement development has occurred are erosional in nature with 0.0 +/- 0.0 cm to 1.5 +/- 0.5 cm of erosion occurring primarily by winds blowing across the surface. Overall these surfaces may show either a small net depositional gain or small erosional loss. (2) Early Holocene surfaces have no well-developed desert pavements, but may have residual gravel deposits in small areas on the surfaces. These surfaces show the most consistent erosional surface areas on which it ranges from1.0 +/-.01 cm to 2.0+/-.01 cm. Fewer depositional forms are found on this age of surface so there is probably a net loss of 1.5 cm across these surfaces. (3) The Late Holocene surfaces show the greatest variability in erosion and deposition. Overbank deposition during floods cover many edges of these surfaces and coppice dune formation also creates depositional features. Erosion rates are highly variable and range from 0.0 +/- 0.0 to a maximum of 2.0+/-.01. Erosion occurs because of the lack of protection of the surface. However, the common areas of deposition probably result in the surface having a small net depositional gain across these surfaces. Thus, the interchannel surfaces of the Fortymile Wash fan show a variety of erosional styles as well as areas of deposition. The fan, therefore, is a dynamic system

  8. Establishment of Populus deltoides under simulated alluvial groundwater declines

    Science.gov (United States)

    Segelquist, Charles A.; Scott, Michael L.; Auble, Gregor T.

    1993-01-01

    Establishment, growth, and survival of seedlings of Populus deltoides subsp. monilifera (plains cottonwood) were examined in an experimental facility simulating five rates of declining alluvial groundwater. The treatments were permanent saturation, drawdown rates of 0.4, 0.7, 2.9 cm/d and immediate drainage. The experiment was conducted outdoors in planters near Fort Collins, Colorado. Seedling survival was highest under the two slowest drawdown rates and declined significantly with faster drawdown rates. The highest growth rate was associated with the drawdown rate of 0.4 cm/d, in which mean shoot height was 2.4 cm and mean root length was 39 am 98 days after planting. Growth of shoots and roots was reduced both by saturated conditions and by the more rapid drawdown rates of 0.7 and 2.9 cm/d. No establishment was observed in the immediate drawdown treatment. Whereas maximum biomass accumulation is associated with the most gradual drawdown or saturated conditions, seedling establishing naturally under such conditions are also most likely to be removed by ice or subsequent flooding. Seedlings establishing in higher topographic positions, in contrast, are subject to increased mortality and reduced shoot growth, resulting from reduced soil moisture. Rapid root extension following establishment allows P. deltoides seedlings to grow across a wide range of groundwater drawdown rates, and thus a variety of positions across a gradient of riparian soil moisture. Our results indicate that in coarse alluvial sands of low fertility, 47% of germinating P. deltoides seeds were able to survive in associated with a drawdown rate of 2.9 cm/d and a final water table depth of 80 cm.

  9. Influence of elevation factor on soil profile texture configuration: a case study of the alluvial plain of Fengqiu County%冲积平原区高程因子对土壤剖面质地构型的影响——以封丘县为例

    Institute of Scientific and Technical Information of China (English)

    檀满枝; 密术晓; 李开丽; 陈杰

    2011-01-01

    Profile texture configuration of the soil in alluvial plains is a crucial factor determining soil water and nutrient conserving and supplying capacity and water and salt movement in the soil.Among the six major soil-forming factors in this regional soil, topography stands out to be the most prominent one.Analysis of the influence of topography on soil profile texture configuration is of important theoretical and practical significance to guiding agricultural production.Using the fuzzy c-means algorithm model nine soil profiles different in texture configuration was defined.Based on the data of thicknesses of the characteristic texture layers of nine soil profiles including sandy, loamy and clayey, surface layers, (0 -(30±10)cm),sandy, loamy and clayey center layers ( ( 30 ± 10 ) cm - ( 60 ± 10) cm) and sandy, loamy and clayey bottom layers ( ( 60 ± 10 )cm-(90±10) cm), nine types of soil profile texture configuration were identified, i.e.loam-clay-loam, loam-loam-clay,loam-clay-clay, clay-clay-clay, sand-sand-clay, sand-sand-sand, sand-loam-loam, loam-loam-sand and loam-loam-loam,among which loam-loam-loam and sand-sand-sand were the dominant types.As a result of frequent flooding by the Yellow River in history, oomplex process of sediment deposition, and in addition fanning practices and soil amelioration measures,like irrigation, deep plowing and field leveling, soil profile texture configuration varied sharply in distribution at a small spatial scale.Comparison analysis of the influence of landform on soil texture profile configuration in the whole study area and the typical area relatively concentrated with various types of soil profile texture configuration, shows that a positive correlation always exists between membership value of the soil profile texture configuration of the sand-sand-sand type and elevation,suggesting that the law prevails that soils in lands relatively high in elevation tend to be sandy, while the influence of landform on soil profile

  10. Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico

    Science.gov (United States)

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

    2016-08-01

    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

  11. Environmental management to preserve the tourist potential on the basis of hydric supply of alluvial soil terracing, between Quebrada Seca, La Nuarque and the Cauca River, Municipality of Olaya, Department of Antioquia

    International Nuclear Information System (INIS)

    It is predict changes on the soils uses at the tourist zone of the right margin of Cauca river, Olaya village, department of Antioquia, republic of Colombia: La Florida and Quebrada Seca sectors, this is the consequence of the growth of tourist population generated by the opening of the Tunel de Occidente. The study area is between the streams: La Seca, La Nuarque and the Cauca river, it has 1367 hectares. The work contemplates to carry out of a hidric balance, the projection of population and its hidric requires to the year 2016, on the basis of the previous ideas it was defined: the offer-demand relation at the year 2016 and the instructive to the environmental management for the conservation, optimization and use of the hidric resources and the environmental arrangement of the territory, reasonable to the density of houses in agreement with the soil's potentials

  12. Alluvial terrace preservation in the Wet Tropics, northeast Queensland, Australia

    Science.gov (United States)

    Hughes, Kate; Croke, Jacky; Bartley, Rebecca; Thompson, Chris; Sharma, Ashneel

    2015-11-01

    Alluvial terraces provide a record of aggradation and incision and are studied to understand river response to changes in climate, tectonic activity, sea level, and factors internal to the river system. Terraces form in all climatic regions and in a range of geomorphic settings; however, relatively few studies have been undertaken in tectonically stable settings in the tropics. The preservation of alluvial terraces in a valley is driven by lateral channel adjustments, vertical incision, aggradation, and channel stability, processes that can be further understood through examining catchment force-resistance frameworks. This study maps and classifies terraces using soil type, surface elevation, sedimentology, and optically stimulated luminescence dating across five tropical catchments in northeast Queensland, Australia. This allowed for the identification of two terraces across the study catchments (T1, T2). The T1 terrace was abandoned ~ 13.9 ka with its subsequent removal occurring until ~ 7.4 ka. Abandonment of the T2 terrace occurred ~ 4.9 ka with removal occurring until ~ 1.2 ka. Differences in the spatial preservation of these terraces were described using an index of terrace preservation (TPI). Assessments of terrace remnant configuration highlighted three main types of terraces: paired, unpaired, and disconnected, indicating the importance of different processes driving preservation. Regional-scale variability in TPI was not strongly correlated with catchment-scale surrogate variables for drivers of terrace erosion and resistance. However, catchment-specific relationships between TPI and erosion-resistance variables were evident and are used here to explain the dominant processes driving preservation in these tropical settings. This study provides an important insight into terrace preservation in the tectonically stable, humid tropics and provides a framework for future research linking the timing of fluvial response to palaeoclimate change.

  13. DIVERSIDAD DE HONGOS MICORRIZÓGENOS ARBUSCULARES DE UNA CRONO-SECUENCIA DE SUELOS ALUVIALES DEGRADADOS POR ACTIVIDAD MINERA EN EL BAJO CAUCA ANTIOQUEÑO, COLOMBIA DIVERSITY OF ARBUSCULAR MYCORRHIZAL FUNGI IN A CHRONO-SEQUENCE OF ALLUVIAL AND DEGRADED SOILS DUE TO MINING PROCESSES IN BAJO CAUCA ANTIOQUEÑO, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Marisol Medina Sierra

    2009-06-01

    undisturbed and disturbed soils form alluvial mining processes. The soils belong to the Tropic Fluvaquent, Typic Dystropept, and Typic Paleudult sub-groups which corresponded to Low, Middle and High terraces, respectively, of the Cauca river at Taraza town. AMF propagules were multiplied in Leonard jars under glasshouse conditions using sterile substrate, modified Hoagland's solution and different fractions of soil used as sources of inoculum, which corresponded to the size of the spores. A first assay was made in maize (Zea mays which allowed mycorrhizal colonization in roots but not spore production. In a second assay, in kudzú (Pueraria phaseoloides AMF spores and colonized roots were obtained with the treatments corresponding to propagules obtained from high terrace and disturbed soil. These treatments presented a significant effect on kudzu yield (P≤0,001 respect to the other treatments. The AMF spores of undisturbed and disturbed soils showed low infective capacity. Nevertheless, propagules of AMF were multiplied in trap cultures, which produced spores of four morphotypes. One of these was identified as G. microagregatum. The polymorphism obtained by RAPD's made possible the differentiation of these morphotypes with the primer OPA2. Similitude above 38% was achieved using UPGMA system. The results indicated that four morphotypes belong to the genus Glomus, but they possibly belong to different species. Our results are promissory in the differentiation of native strains of AMF with low number of spores collected from soil samples in rehabilitation processes, which normally is unknown.

  14. CHANNEL WIDENING DURING DEGRADATION OF ALLUVIAL RIVERS

    Institute of Scientific and Technical Information of China (English)

    Guangqian WANG; Junqiang XIA

    2001-01-01

    This paper first describes the phenomenon of channel widening during degradation of alluvial rivers,explains the mechanisms of channel widening, and analyzes the stability of cohesive riverbank. Then a one-dimensional mathematical model is developed to simulate the transport of non-uniform suspended sediments, with a sub-model for the simulation of channel widening, and is used to study the process of channel widening during degradation. The effects of different incident flow and sediment conditions and different riverbank material characteristics on channel widening and bed degradation are compared.Finally, main factors that control the deformation processes are identified.

  15. Soil plant transfer coefficient of 14C-carbofuran in brassica sp. vegetable agroecosystem

    International Nuclear Information System (INIS)

    The soil plant transfer coefficient or f factor of 14C-carbofuran pesticide was studied in outdoor lysimeter experiment consisting of Brassica sp. vegetable crop, riverine alluvial clayey soil and Bungor series sandy loam soil. Soil transfer coefficients at 0-10 cm soil depth were 4.38 ± 0.30, 5.76 ± 1.04, 0.99 ± 0.25 and 2.66 ± 0.71; from IX recommended application rate in alluvial soil, 2X recommended application rate in alluvial soil, IX recommended application rate in Bungor soil and 2X recommended application rate in Bungor soil, respectively. At 0-25 cm soil depth, soil plant transfer coefficients were 8.96 ± 0.91, 10.40 ± 2.63, 2.34 ± 0.68 and 619 ±1.40, from IX recommended application rate in alluvial soil, 2X recommended application rate in alluvial soil, IX recommended application rate in Bungor soil and 2X recommended application rate in Bungor soil, respectively. At 77 days after treatment (DAT), the soil plant transfer coefficient was significantly higher in riverine alluvial soil than Bungor soil whereas shoot and root growth was significantly higher in Bungor soil than in riverine alluvial soil. At both 0-10 cm Brassica sp. rooting depth and 0-25 cm soil depth, the soil plant transfer coefficient was significantly higher in 2X recommended application rate of 14C-carbofuran as compared to IX recommended application rate, in both Bungor and riverine alluvial soils. (Author)

  16. Numerical modelling of shaking effects due to strong motions on the tiber alluvial deposits in Rome (Italy)

    CERN Document Server

    Bonilla, Fabian; Gelis, Céline; Giacomi, Anna Chiara; Lenti, Luca; Martino, Salvatore; d'Avila, Maria Paola Santisi; Semblat, Jean-François

    2016-01-01

    A multidisciplinary approach is proposed for evaluating the effects of shaking due to strong motions on the Tiber river alluvial deposits in Rome's historical centre. At this aim, a detailed 3D geological model of the Tiber river alluvial deposit has been constructed and a numerical analysis of site response was performed along two geological sections across the historical centre of Rome. The numerical models were performed in both 1D and 2D configurations assuming linear and nonlinear conditions, by applying a three component seismic input. The results show that the maximum shear strains are strongly conditioned by the layer geometries (i.e. 2D or 1D conditions) and by the soil heterogeneity. Moreover, the reliability of the maximum strains obtained by numerical modeling is discussed comparing these values respect to both the volumetric and the degradation dynamic thresholds of the considered soils.

  17. Level III Ecoregions of the Mississippi Alluvial Plain

    Data.gov (United States)

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

  18. Level IV Ecoregions of the Mississippi Alluvial Plain

    Data.gov (United States)

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

  19. Alluvial basin statistics of the Southwest Principal Aquifers (SWPA) study.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — SWPA_alvbsn is a vector dataset of alluvial-fill basin statistics for the Southwest United States. Statistics for each basin include physical details such as area,...

  20. Aquifers of Alluvial and Glacial Origin - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the alluvial and glacial aquifers north of the southern-most line of glaciation. Aquifers are shown in the States of Maine,...

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

    Science.gov (United States)

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

    2008-01-01

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

  2. Alluvial plain dynamics in the southern Amazonian foreland basin

    OpenAIRE

    Lombardo, U

    2015-01-01

    Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation ...

  3. Thermal tracer tests for characterizing a shallow alluvial aquifer

    OpenAIRE

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

    2014-01-01

    Using heat as an active tracer in different types of aquifers is a topic of increasing interest [e.g. Vandenbohede et al.; 2008, Wagner et al., 2013; Read et al., 2013]. In this study, we investigate the potential interest of coupling heat and solute tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer i...

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

    Science.gov (United States)

    Larsen, Annegret; May, Jan-Hendrick

    2016-04-01

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

  5. Analysis of the Sediment Hydrograph of the alluvial deltas in the Apalachicola River, Florida

    Science.gov (United States)

    Daranpob, A.; Hagen, S.; Passeri, D.; Smar, D. E.

    2011-12-01

    Channel and alluvial characteristics in lowlands are the products of boundary conditions and driving forces. The boundary conditions normally include materials and land cover types, such as soil type and vegetation cover. General driving forces include discharge rate, sediment loadings, tides and waves. Deltas built up of river-transported sediment occur in depositional zones of the river mouth in flat terrains and slow currents. Total sediment load depends on two major abilities of the river, the river shear stress and capacity. The shear stress determines transport of a given sediment grain size, normally expressed as tractive force. The river capacity determines the total load or quantity of total sediments transported across a section of the river, generally expressed as the sediment loading rate. The shear stress and sediment loading rate are relatively easy to measure in the headwater and transfer zones where streams form a v-shape valley and the river begins to form defined banks compared to the deposition zone where rivers broaden across lower elevation landscapes creating alluvial forms such as deltas. Determinations of deposition and re-suspension of sediment in fluvial systems are complicated due to exerting tidal, wind, and wave forces. Cyclic forces of tides and waves repeatedly change the sediment transport and deposition rate spatially and temporally in alluvial fans. However, the influence decreases with water depth. Understanding the transport, deposition, and re-suspension of sediments in the fluvial zone would provide a better understanding of the morphology of landscape in lowland estuaries such as the Apalachicola Bay and its estuary systems. The Apalachicola River system is located in the Florida Panhandle. Shelf sedimentation process is not a strong influence in this region because it is protected by barrier islands from direct ocean forces of the Gulf of Mexico. This research explores the characteristic of suspended sediment loadings in

  6. Hydrogeochemistry of alluvial groundwaters in an agricultural area: an implication for groundwater contamination susceptibility.

    Science.gov (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

    2004-04-01

    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. PMID:14987935

  7. Heavy metals in Ratnapura alluvial gem sediments, Sri Lanka

    Science.gov (United States)

    Vithanage, M. S.; Hettiarachchi, J. K.; Rajapaksha, A. U.; Wijesekara, H.; Hewawasam, T.

    2011-12-01

    The valuable gems in Sri Lanka are found from the sedimentary gem deposits in Ratnapura District, which are found as alluvial deposits some are about >50 m deep. Gem bearing gravel layer is taken out from the mine, washed by panning to recover the gem minerals in the heavy mineral fraction, is a common practice in the gem mining area. Gem bearing sediment layer is associated with different heavy minerals in which different trace metals as Co, Cr, Cu, Al, Zr, Pb and As also can be present. During panning, the sediment is washed away and the heavy metals attached to the sediments are released into the environment. Hence we studied the lability and bioavailability of arsenic and other heavy metals from the gem sediments. Sediment samples were collected from 15 small scale gem mines (3 soil layers- top, gem mineral layer and layer below gem bearing gravel layer), air dried and sieved to obtain 150 mg/kg), Cu (>150 mg/kg), Pb (>400 mg/kg), Zn (>600 mg/kg) and Co ions (>100 mg/kg). Arsenite in the gem sediments were low and recorded as Co>Zn>Mn>Ni>Cu>Pb. Sediments from few gem pits showed considerably high concentrations of metals analyzed. In some places Fe, Ni, Cu, Zn reported high in bioavailable fractions 70, 25, 20, 10 mg/kg respectively. Mobilization of these metals may increase due to changes in the pH and the presence of other ions in the environment. High concentrations of toxic metals in exchangeable and bioavailable fractions indicate the risk on plant and animals as well as the open water bodies and groundwater sources.

  8. The provenance of Borneo's enigmatic alluvial diamonds

    Science.gov (United States)

    White, Lloyd; Graham, Ian; Tanner, Dominique; Hall, Robert; Armstrong, Richard; Yaxley, Greg; Barron, Larry; Spencer, Lee; van Leeuwen, Theo

    2016-04-01

    Gem-quality diamonds occur in several alluvial deposits across central and southern Borneo. Borneo has been a known source of diamonds for centuries, but the location of their primary igneous source remains enigmatic. Numerous geological models have been proposed to explain the distribution of Borneo's diamonds. To assess these models, we used a variety of techniques to examine heavy minerals from Kalimantan's Cempaka paleoalluvial diamond deposit. This involved collecting U-Pb isotopic data, fission track and trace element geochemistry of zircon as well as major element geochemical data of spinels and morphological descriptions of zircon and diamond. Our results indicate that the Cempaka diamonds were likely derived from at least two sources, one which was relatively local and/or involved little reworking, and the other more distal recording several periods of reworking. The distal diamond source is interpreted to be diamond-bearing pipes that intruded the basement of a block that: (1) rifted from northwest Australia (East Java or SW Borneo) and the diamonds were recycled into its sedimentary cover, or: (2) were emplaced elsewhere (e.g. NW Australia) and transported to a block (e.g. East Java or SW Borneo). Both of these scenarios require the diamonds to be transported with the block when it rifted from NW Australia in the Late Jurassic. The 'local' diamonds could be associated with ophiolitic rocks that are exposed in the nearby Meratus Mountains, or could be diamondiferous diatremes associated with eroded Miocene high-K alkaline intrusions north of the Barito Basin. If this were the case, these intrusions would indicate that the lithosphere beneath SW Borneo is thick (~150 km or greater).

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

    Directory of Open Access Journals (Sweden)

    Jędrzej Wierzbicki

    2015-11-01

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

  10. Hydrological and chemical budgets of a mire pool formed on alluvial lowland of Hokkaido, northern Japan

    Science.gov (United States)

    Kizuka, Toshikazu; Yamada, Hiroyuki; Hirano, Takashi

    2011-04-01

    SummaryMire pools - permanently water-filled depressions on peatlands - provide important habitats for myriad organisms. Recently, water balance change and eutrophication resulting from agricultural development are increasingly evident in mire pools of alluvial lowlands. Conservation of mire pool hydrochemistry is necessary. We investigated the hydrological and chemical budgets of a pristine mire pool, Akanuma Pool (95,280 m 2 area; 1.8 m mean depth), located in Kushiro Mire in Hokkaido, northern Japan, during its ice-free period (April-November) in 2007-2008. Thereby we elucidated the hydrochemical characteristics of mire pools formed on alluvial lowlands. Surface water inflow and surface water outflow dominated the hydrological budget, respectively representing 18.3 and 20.2 mm day -1. Groundwater seepage through the pool bottom and surface water inflow mainly supplied the lake water with total nitrogen and Ca 2+. Total phosphorus was supplied mostly by groundwater seepage through the bottom. These chemical constituents were run off from the pool mostly by surface water outflow. The input and output fluxes of water were 16-20 times greater than those of North American mire pools because of Hokkaido's higher values of precipitation minus evapotranspiration ( P- ET). Moreover, the Ca 2+ input into the Akanuma Pool was several times greater than those reported from North American studies. Alluvial mineral soil under the peat layer supplied large amounts of nutrients and mineral ions including Ca 2+. These results demonstrate that Hokkaido mire pools' hydrochemical characteristics differ greatly from those of pools in North America. Furthermore, each hydrological budget component maintained a constant fraction throughout the two year study period, although the absolute flow rate varied concomitantly with the precipitation level. Maintaining this budget stability is important for the conservation of mire pool hydrochemistry.

  11. Holocene alluvial fills in the South Loup Valley, Nebraska

    Science.gov (United States)

    May, David W.

    1989-07-01

    Four Holocene alluvial fills are present in Nebraska's South Loup River valley. Fill IV, the oldest and thickest, was deposited between 10,200 and 4800 14C yr B.P.; Fill III has an age of about 3000 14C yr B.P.; Fill II is younger than 2100 and older than 900 14C yr B.P.; and Fill I is younger than 900 14C yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.

  12. Geomorphic characterization of the Fortymile Wash alluvial fan, Nye County, Nevada, in support of the Yucca Mountain Project

    Science.gov (United States)

    Cline, M.; Delong, S.; Pelletier, J.

    2005-12-01

    In the event of an unlikely volcanic eruption through the proposed high-level radioactive waste repository at Yucca Mountain, contaminated ash may be deposited in portions of the Fortymile Wash drainage basin and subsequently redistributed to the Fortymile Wash alluvial fan by fluvial processes. Characterization of the Fortymile Wash alluvial fan has been undertaken as part of an effort to quantify the transport of contaminated ash throughout the fluvial system, especially to define 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 for 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 137Cs fallout to determine radionuclide 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 137Cs profiles collected on the different surfaces of the fan.

  13. Rainfall-induced nutrient losses from manure-fertilized farmland in an alluvial plain.

    Science.gov (United States)

    Wang, Yiyao; Li, Huaizheng; Xu, Zuxin

    2016-01-01

    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.

  14. Multilevel approach to the geomorphological setting of an alluvial plain in the Alpine environment

    Science.gov (United States)

    Minciotti, Nancy A.; Brivio, Pietro A.; Zilioli, Eugenio

    1995-11-01

    This paper presents an integrated use of cartography and remote sensing imagery supplied by satellite and aircraft to study the geomorphological aspects of an alluvial plain for archaeological purposes. The study area is located at the confluence of the Valtellina (Adda River) and Lower Mera River valleys in northern Italy. Landsat data and aerial photographs were used to study the partial filling of the Lake Como lacustrine basin resulting from the progradation of the Adda River delta. Different soil humidity content, related to variable grain size of the alluvial deposits is an indicator of ancient river beds which were formed in this area before the nineteenth century artificial rectification of the River Adda's final stretch. Profiles coincident with geological sections gained by geophysical sounding were performed on the remote sensing imagery to verify eventual correspondence of depositional features with different analysis techniques. The integration of remote sensing multilevel data with cartography and archaeological evidences has been useful for the assessment of the paleoenvironment which conditioned human settlements.

  15. Turnover Rates of Fall Migrating Pectoral Sandpipers Through the Lower Mississippi Alluvial Valley

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mississippi Alluvial Valley (MA V) is the historic alluvial floodplain of the Lower Mississippi River. Most of the MAV is located in Arkansas, Louisiana, and...

  16. 44 CFR 65.13 - Mapping and map revisions for areas subject to alluvial fan flooding.

    Science.gov (United States)

    2010-10-01

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

  17. APPLICABILITY OF THE BEND DEVELOPMENT THEORY IN NATURAL ALLUVIAL RIVERS

    Institute of Scientific and Technical Information of China (English)

    M.M.RAHMAN; M.A.HAQUE; M.M.HOQUE

    2002-01-01

    The theoretical conditions for the bend development or attenuation have been reviewed and tested for a study reach of the Meghna river.The field observations in the natural alluvial meander do not support the theories developed for bend development.The limitations of the theory to apply in the natural meandering river are discussed.

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

    Science.gov (United States)

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

    2015-01-01

    We used tree-ring analysis to examine radial growth response of a common, moderately flood-tolerant species (Fraxinus pennsylvanica Marshall) to hydrologic and climatic variability for > 40 years before and after hydrologic modifications affecting two forest stands in the Mississippi River Alluvial Valley (USA): a stand without levees below dams and a stand within a ring levee. At the stand without levees below dams, spring flood stages decreased and overall growth increased after dam construction, which we attribute to a reduction in flood stress. At the stand within a ring levee, growth responded to the elimination of overbank flooding by shifting from being positively correlated with river stage to not being correlated with river stage. In general, growth in swales was positively correlated with river stage and Palmer Drought Severity Index (an index of soil moisture) for longer periods than flats. Growth decreased after levee construction, but swales were less impacted than flats likely because of differences in elevation and soils provide higher soil moisture. Results of this study indicate that broad-scale hydrologic processes differ in their effects on the flood regime, and the effects on growth of moderately flood-tolerant species such as F. pennsylvanica can be mediated by local-scale factors such as topographic position, which affects soil moisture.

  19. Recharge sources and hydrogeochemical evolution of groundwater in alluvial basins in arid central Australia

    Science.gov (United States)

    Vanderzalm, J. L.; Jeuken, B. M.; Wischusen, J. D. H.; Pavelic, P.; Le Gal La Salle, C.; Knapton, A.; Dillon, P. J.

    2011-01-01

    SummaryIt is necessary to define the role of various sources of recharge in the surficial alluvial aquifer system in arid Alice Springs in central Australia, for future management of water resources in the region. Multiple sources of natural recharge include infiltration from ephemeral stream flow in the Todd River; groundwater throughflow between connected alluvial basins; regional groundwater flow from the underlying Tertiary aquifer; and diffuse recharge. In addition treatment, storage and irrigation reuse of Alice Springs' waste water has resulted in additional recharge of effluent, via infiltration. Water resource management plans for the region include effluent reuse through Soil Aquifer Treatment (SAT) within one of the connected alluvial basins, with the purpose of managing the excess waste water overflows while also supplementing groundwater resources for irrigation and protecting their quality. Hydrogeochemical tracers, chloride and the stable isotopes of water, were used in a three-member mixing model to define and quantify the major recharge sources. The mixing model was not sensitive enough to quantify minor contributions from effluent in groundwater that were identified only by an evaporated isotopic signature. The contribution of the multiple recharge sources varied spatially with proximity to the recharge source; with Todd River, effluent and Town Basin throughflow contributing to the Inner Farm Basin groundwater. The Outer Farm Basin was largely influenced by the Todd River, the Inner Farm Basin throughflow and the older Tertiary aquifer. While Inner Farm groundwater throughflow contains an effluent component, only Outer Farm Basin groundwater near the interface between the two basins clearly illustrated an effluent signature. Aside from this, effluent recharge was not evident in the Outer Farm Basin, indicating that past unmanaged recharge practices will not mask signs of Managed Aquifer Recharge through the Soil Aquifer Treatment (SAT) operation

  20. Modeling analysis of ground water recharge potential on alluvial fans using limited data.

    Science.gov (United States)

    Munévar, A; Mariño, M A

    1999-01-01

    A modeling approach is developed to evaluate the potential for artificial recharge on alluvial fans in the Salinas Valley, California, using limited data of soil texture, soil hydraulic properties, and interwell stratigraphy. Promising areas for surface recharge are identified and mapped on a broad-scale using soil surveys, geologic investigations, permeability tests, and seasonal ground water response to rainfall and runoff. Two-dimensional representations of the vadose zone at selected sites are then constructed from drillers'logs and soil material types are estimated. Next, hydraulic properties are assigned to each soil material type by comparing them to laboratory-tested cores of similar soils taken from one site. Finally, water flow through the vadose zone is modeled in two dimensions at seven sites using a transient, finite-difference, variably saturated flow model. Average infiltration rates range from 0.84 to 1.54 cm/hr and recharge efficiency, the percentage of infiltrated water that reaches the water table, varies from 51% to 79%. Infiltration rates and recharge efficiency are found to be relatively insensitive to recharge basin ponding depth due to the thickness of the vadose zones modeled (31 to 84 m). The impact of artificial recharge on the Salinas Valley ground water basin is investigated by simulating the regional ground water response to surface spreading and streamflow augmentation with a recently calibrated, finite-element, ground water-surface water model for the basin. It was determined that a combined approach of surface recharge and streamflow augmentation significantly reduces the state of ground water overdraft and, to a lesser extent, reduces the rate of sea water intrusion.

  1. Morphometric Characterization and Classification of Alluvial Fans in Eastern Oman

    Science.gov (United States)

    Leuschner, Annette; Mattern, Frank; van Gasselt, Stephan

    2015-04-01

    Morphologic characteristics of alluvial fans are a product of fluvial erosion, transportation and deposition. Consequently, fans have been described and defined on the basis of their shape, their composition, conditions and processes under which they from, their so-called "controlling factors", and their geomorphic and tectonic settings. The aim of our study is to reconstruct the morphologic evolution and to relate it to past and present climate conditions. In order to achieve this, we first characterize alluvial fans based on their climatic settings and conditions and classify them accordingly using satellite image data and digital elevation models. For mapping of different alluvial fan bodies multispectral images of the Landsat Enhanced Thematic Mapper (ETM+) with a scale of 15-30 m/px were utilized. For the detection of morphometric parameters as input data for subsequent hydrological studies digital terrain model data of the Shuttle Radar Topography Mission (SRTM) and the ASTER GDEM with a scale of 90 m/px and 30m, respectively, were used. Using these datasets morphological characteristics, such as sizes of drainage basins, transport areas and areas of deposition derived from spatial semi-automatic analysis, have been computed. The area of Muscat at the Oman Mountains has been selected as a study area because of its size, accessibility and climate conditions and it is considered well-suited for studying the development of alluvial fans and their controlling factors. The Oman Mountains are well-known for the world's largest intact and best exposed obducted ophiolite complex, the Semail Ophiolite. They are today subjected to a mild desert climate (Bwh), influenced by the Indian Ocean but they have experienced extensive pluvial periods in the geologic past. Formation of alluvial fans was, therefore, likely triggered by the interplay of increased sediment production caused by high rainfalls with enhanced erosion of hillslopes and transport rates during pluvial

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

    Science.gov (United States)

    Bektas Balcik, F.

    2012-12-01

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

  3. Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front

    Science.gov (United States)

    Sohn, M.F.; Mahan, S.A.; Knott, J.R.; Bowman, D.D.

    2007-01-01

    Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but their ages have generally eluded researchers until recently. Most mapping efforts have recognized at least four major relative-age groupings (Q1 (oldest), Q2, Q3, and Q4 (youngest)), using observed changes in surface soils and morphology, relation to the drainage net, and development of desert pavement. Obtaining numerical age determinations for these morphologic stages has proven challenging. We report the first optically stimulated luminescence (OSL) ages for three of these four stages deposited within alluvial-fans along the tectonically active Black Mountains of Death Valley. Deposits showing distinct, remnant bar and swale topography (Q3b) have OSL ages from 7 to 4 ka., whereas those with moderate to poorly developed desert pavement and located farther above the active channel (Q3a) have OSL ages from 17 to 11 ka. Geomorphically older deposits with well-developed desert pavement (Q2d) have OSL ages ???25 ka. Using this OSL-based chronology, we note that alluvial-fan deposition along this tectonically active mountain front corresponds to both wet-to-dry and dry-to-wet climate changes recorded globally and regionally. These findings underscore the influence of climate change on alluvial fan deposition in arid and semi-arid regions. ?? 2007 Elsevier Ltd and INQUA.

  4. Characterisation of the surface morphology of an alpine alluvial fan using airborne LiDAR

    OpenAIRE

    M. Cavalli; L. Marchi

    2008-01-01

    International audience Alluvial fans of alpine torrents are both natural deposition areas for sediment discharged by floods and debris flows, and preferred sites for agriculture and settlements. Hazard assessment on alluvial fans depends on proper identification of flow processes and their potential intensity. This study used LiDAR data to examine the morphology of the alluvial fan of a small alpine stream (Moscardo Torrent, Eastern Italian Alps). A high-resolution DTM from LiDAR data was ...

  5. Alluvial plain dynamics in the southern Amazonian foreland basin

    Directory of Open Access Journals (Sweden)

    U. Lombardo

    2015-10-01

    Full Text Available Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays triggered by above normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all the twelve tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. I found that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid- to late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a year to decade time scale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.

  6. Alluvial plain dynamics in the southern Amazonian foreland basin

    Science.gov (United States)

    Lombardo, Umberto

    2016-05-01

    Alluvial plains are formed with sediments that rivers deposit on the adjacent flood-basin, mainly through crevasse splays and avulsions. These result from a combination of processes, some of which push the river towards the crevasse threshold, while others act as triggers. Based on the floodplain sedimentation patterns of large rivers in the southern Amazonian foreland basin, it has been suggested that alluvial plain sediment accumulation is primarily the result of river crevasse splays and sheet sands triggered by above-normal precipitation events due to La Niña. However, more than 90 % of the Amazonian river network is made of small rivers and it is unknown whether small river floodplain sedimentation is influenced by the ENSO cycle as well. Using Landsat images from 1984 to 2014, here I analyse the behaviour of all 12 tributaries of the Río Mamoré with a catchment in the Andes. I show that these are very active rivers and that the frequency of crevasses is not linked to ENSO activity. The data suggest that most of the sediments eroded from the Andes by the tributaries of the Mamoré are deposited in the alluvial plains, before reaching the parent river. The mid-to-late Holocene paleo-channels of these rivers are located tens of kilometres further away from the Andes than the modern crevasses. I conclude that the frequency of crevasses is controlled by intrabasinal processes that act on a yearly to decadal timescale, while the average location of the crevasses is controlled by climatic or neo-tectonic events that act on a millennial scale. Finally, I discuss the implications of river dynamics on rural livelihoods and biodiversity in the Llanos de Moxos, a seasonally flooded savannah covering most of the southern Amazonian foreland basin and the world's largest RAMSAR site.

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

    Science.gov (United States)

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

    2010-01-01

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

  8. Combined velocity and depth mapping on developing laboratory alluvial fans

    Science.gov (United States)

    Hamilton, P.; Strom, K. B.; Hoyal, D. C.

    2011-12-01

    Large-scale particle image velocimetry (LSPIV) is a nonintrusive method for measuring free-surface velocities using tracer patterns in a sequence of images. This method has been applied in both natural rivers and large-scale hydraulic models (Muste et al., 2008). Here the method is used to map channel and sheet flow velocity during the development of laboratory-scale alluvial fans. Measuring the time and space varying hydraulics on laboratory fans by traditional methods is not practical since flows are quite shallow (~1 cm). Additionally, the highly dynamic environment makes positioning of traditional probe-type instruments difficult and their physical presence could alter autogenic fan evolution. These difficulties can be overcome by using particle image velocimetry techniques. Furthermore, images collected in the LSPIV method can be used to extract flow depth using a calibrated dye-intensity method (Gran and Paola, 2001). This allows for simultaneous measurement of flow velocity and depth everywhere over the fan at any point in time. To validate the method, a set of controlled small-scale experiments were run for depths ranging from 0.2-1.5 cm and velocities from 10-100 cm/sec. Comparison of the LSPIV and dye-intensity method measurements to the known values indicated that the methodology was able to accurately capture simultaneous flow velocity and depth in this range of conditions, i.e., those encountered during the development of laboratory-scale alluvial fans and streams. The method is then used to map the hydraulics associated with various fan processes during development as demonstrated in figure 1. The ability to measure hydraulic properties during fan development is important since physical models provide an arena for observing the time evolution and morphodynamic feedback in depositional systems such as alluvial fans.

  9. Degradation of the Mitchell River fluvial megafan by alluvial gully erosion increased by post-European land use change, Queensland, Australia

    Science.gov (United States)

    Shellberg, J. G.; Spencer, J.; Brooks, A. P.; Pietsch, T. J.

    2016-08-01

    Along low gradient rivers in northern Australia, there is widespread gully erosion into unconfined alluvial deposits of active and inactive floodplains. On the Mitchell River fluvial megafan in northern Queensland, river incision and fan-head trenching into Pleistocene and Holocene megafan units with sodic soils created the potential energy for a secondary cycle of erosion. In this study, rates of alluvial gully erosion into incipiently-unstable channel banks and/or pre-existing floodplain features were quantified to assess the influence of land use change following European settlement. Alluvial gully scarp retreat rates were quantified at 18 sites across the megafan using recent GPS surveys and historic air photos, demonstrating rapid increases in gully area of 1.2 to 10 times their 1949 values. Extrapolation of gully area growth trends backward in time suggested that the current widespread phase of gullying initiated between 1880 and 1950, which is post-European settlement. This is supported by young optically stimulated luminescence (OSL) dates of gully inset-floodplain deposits, LiDAR terrain analysis, historic explorer accounts of earlier gully types, and archival records of cattle numbers and land management. It is deduced that intense cattle grazing and associated disturbance concentrated in the riparian zones during the dry season promoted gully erosion in the wet season along steep banks, adjacent floodplain hollows and precursor gullies. This is a result of reduced native grass cover, increased physical disturbance of soils, and the concentration of water runoff along cattle tracks, in addition to fire regime modifications, episodic drought, and the establishment of exotic weed and grass species. Geomorphic processes operating over geologic time across the fluvial megafan predisposed the landscape to being pushed by land used change across an intrinsically close geomorphic threshold towards instability. The evolution of these alluvial gullies is discussed

  10. Butachlor inhibits production and oxidation of methane in tropical rice soils under flooded condition.

    Science.gov (United States)

    Mohanty, S R; Nayak, D R; Babu, Y J; Adhya, T K

    2004-01-01

    In laboratory incubation experiments, application of a commercial formulation of the herbicide butachlor (N-butoxymethyl-2-chloro-2',6'-diethyl acetanilide) to three tropical rice soils, widely differing in their physicochemical characteristics, under flooded condition inhibited methane (CH4) production. The inhibitory effect was concentration dependent and most remarkable in the alluvial soil. Thus, following application of butachlor at 5, 10, 50 and 100 microg g(-1) soil, respectively, cumulative CH4 production in the alluvial soil was inhibited by 15%, 31%, 91% and 98% over unamended control. Since CH4 production was less pronounced in the sandy loam and acid sulfate soil, the impact of amendment with butchalor, albeit inhibitory, was less extensive than the alluvial soil. Inhibition of CH4 production in butachlor-amended alluvial soil was related to the prevention in the drop in redox potential as well as low methanogenic bacterial population especially at high concentrations of butachlor. CH4 oxidation was also inhibited in butachlor-amended alluvial soil with the inhibitory effect being more prevalent under flooded condition. Inhibition in CH4 oxidation was related to a reduction in the population of soluble methane monooxygenase producing methanotrophs. Results demonstrate that butachlor, a commonly used herbicide in rice cultivation, even at very low concentrations can affect CH4 production and its oxidation, thereby influencing the biogeochemical cycle of CH4 in flooded rice soils.

  11. Radon hazard in shallow groundwaters II: Dry season fracture drainage and alluvial fan upwelling

    Energy Technology Data Exchange (ETDEWEB)

    Tommasone, F. Pascale [Office of Civil Protection, Meteorology, Climatology and Natural Hazards, Piazza Municipio, 81051 Pietramelara, Caserta (Italy); De Francesco, S., E-mail: stefano.defrancesco@unina2.it [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); Cuoco, E.; Verrengia, G.; Santoro, D. [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); Tedesco, D. [Department of Environmental Sciences, University of Caserta, Via Vivaldi, 43, 81100 Caserta (Italy); C.N.R. (Italian National Council), Institute of Environmental Geology and Geological Engineering, Piazzale Aldo Moro, 00100 Roma (Italy)

    2011-08-15

    {sup 222}Rn concentrations have been measured in a well located on the edge of a large Pleistocene-Holocene fan and belonging to the shallow pyroclastic aquifer of the Pietramelara Plain, southern Italy. The aim of this study has been both to characterise the hydrological inputs that determine the influx of {sup 222}Rn to the shallow aquifer and to understand the correlations between {sup 222}Rn, major ions, physical-chemical parameters and rainfall. Results obtained from the time series indicate that the studied well shows a {sup 222}Rn variability that is inconsistent with a mechanism of pure hydrological amplification, such as described in Radon hazard in shallow groundwaters: Amplification and long term variability induced by rainfall (De Francesco et al., 2010a). On the contrary, in this well hydrological amplification appears to be mainly tied to the upwelling of alluvial fan waters, rich in radon, in response to pistoning from recharge in the carbonate substrate. This upwelling of alluvial fan waters occurs during almost the whole period of the annual recharge and is also responsible of the constant increase in {sup 222}Rn levels during the autumn-spring period, when both the water table level and weekly rainfall totals drop. Furthermore, a rapid delivery mechanism for {sup 222}Rn likely operates through fracture drainage in concomitance with the very first late summer-early autumn rains, when rainfall totals appear largely insufficient to saturate the soil storage capacity. Results obtained from this study appear to be particularly significant in both radon hazard zoning in relation to the shallow aquifer and possibly also for indoor radon, owing to possible shallow aquifer-soil-building exchanges. Moreover, both the spike-like events and the long wave monthly scale background fluctuations detected can also have potential significance in interpreting {sup 222}Rn time series data as seismic and/or volcanic precursors. Finally, {sup 222}Rn has proved to be an

  12. Anabranching Channel Patterns: the Kingdom of Large Alluvial Rivers

    Science.gov (United States)

    Latrubesse, Edgardo

    2015-04-01

    For a long time anabranching patterns were primarily restricted to "exotic and remote" zones in arid systems such as Australia. For that reason, they were not accepted as a major topic of discussion in our discipline, which was based on concepts principally derived from case studies in braided and meandering rivers of the Northern Hemisphere. However, anabranching alluvial patterns are widespread in a variety of environments and scales, from arid small rivers to alluvial reaches of giant rivers such as the Amazon, Congo, and Negro. The largest rivers of the world in water discharge are anabranching, and the majority of the forty-five largest rivers (water discharges >5000m3s-1) are dominantly anabranching systems. Only a small number of rivers with meandering patterns, or sinuous with branches (meandering-tendency to anabranch) are part of the largest rivers group. The present large anabranching rivers flowing on lowlands and well developed floodplains have in common a characteristic very slow slopes, specific stream power of styles are not specifically related to a single explanatory "physically based theory" but to a variety of morphological processes, complex-channel floodplain interactions and the geologic characteristics of the valleys. Once considered a kind of oddity, anabranching rivers must be considered major and fundamental representatives of the fluvial world.

  13. 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

    2011-12-01

    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.

  14. Simulation of the transfer of organochlorine pollutants in an alluvial aquifer in an alpine valley: the case of tetrachloroethene

    Science.gov (United States)

    Kouamé, A. A.; Jaboyedoff, M.; Tacher, L.; Derron, M.-H.

    2012-04-01

    During a series of environmental analysis carried out in soil and groundwater in the Alpine Valley (Rhone valley Western Switzerland), were identified high levels of chlorinated solvents, particularly the tetrachloroethene. The leakage of this pollutant originates from industry. The geological substratum in this part of the valley is mainly composed of alluvial deposits and the deposit of a large rock avalanche. The sediments are composed of sandy silt, sandy clay, sand and gravel. The rock avalanche deposit which is the wall of the alluvial aquifer consists of fine materials, stones and large debris mainly of limestone. The investigations developed in this area have shown the presence of a contaminant plume of 60 m long and 35 m wide approximately. Thus the technique of venting / sparging was proposed as remediation measure. Despite the effectiveness of this technique, it turns out that there are still some pockets of contamination of groundwater in the area. In order to assess the potential pollution, a numerical modeling was developed by using the Visual Modflow software. The stages of this modeling are: • Selecting the parameters of the models; • Developing conceptual and numerical models; • Calibration and validation of the model; • Reproducing the observed concentrations; • Sensitivity analysis; • Making a parametric study to see at different stages the tetrachloroethene plume. The first results of the simulation show a slow leakage of the pollutant forming a pocket in the water flow direction.

  15. Statistic inversion of multi-zone transition probability models for aquifer characterization in alluvial fans

    CERN Document Server

    Zhu, Lin; Gong, Huili; Gable, Carl; Teatini, Pietro

    2015-01-01

    Understanding the heterogeneity arising from the complex architecture of sedimentary sequences in alluvial fans is challenging. This paper develops a statistical inverse framework in a multi-zone transition probability approach for characterizing the heterogeneity in alluvial fans. An analytical solution of the transition probability matrix is used to define the statistical relationships among different hydrofacies and their mean lengths, integral scales, and volumetric proportions. A statistical inversion is conducted to identify the multi-zone transition probability models and estimate the optimal statistical parameters using the modified Gauss-Newton-Levenberg-Marquardt method. The Jacobian matrix is computed by the sensitivity equation method, which results in an accurate inverse solution with quantification of parameter uncertainty. We use the Chaobai River alluvial fan in the Beijing Plain, China, as an example for elucidating the methodology of alluvial fan characterization. The alluvial fan is divided...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-11

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

  17. Comparison of planform multi-channel network characteristics of alluvial and bedrock constrained large rivers

    Science.gov (United States)

    Carling, P. A.; Meshkova, L.; Robinson, R. A.

    2011-12-01

    The Mekong River in northern Cambodia is an multi-channel mixed bedrock-alluvial river but it was poorly researched until present. Preliminary study of the Mekong geomorphology was conducted by gathering existing knowledge of its geological and tectonic settings, specific riparian vegetation and ancient alluvial terraces in which the river has incised since the Holocene. Altogether this process has allowed a geomorphological portrait of the river to be composed within the Quaternary context. Following this outline, the planform characteristics of the Mekong River network are compared, using analysis of channel network and islands configurations, with the fluvial patterns of the Orange River (South Africa), Upper Columbia River (Canada) and the Ganga River (India, Bangladesh). These rivers are selected as examples of multi-channel mixed bedrock alluvial, anastomosed alluvial and braided alluvial rivers respectively. Network parameters such as channel bifurcation angles asymmetry, sinuosity, braid intensity and island morphometric shape metrics are compared and contrasted between bedrock and alluvial systems. In addition, regional and local topographic trend surfaces produced for each river planform help explain the local changes in river direction and the degree of anastomosis, and distinguish the bedrock-alluvial rivers from the alluvial rivers. Variations between planform characteristics are to be explained by channel forming processes and in the case of mixed bedrock-alluvial rivers mediated by structural control. Channel metrics (derived at the reach-scale) provide some discrimination between different multi-channel patterns but are not always robust when considered singly. In contrast, island shape metrics (obtained at subreach-scale) allow robust discrimination between alluvial and bedrock systems.

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

    NARCIS (Netherlands)

    Gouw, M.J.P.

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    G. Di Giulio

    2008-06-01

    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.

  20. Methodologies for hydraulic hazard mapping in alluvial fan areas

    Science.gov (United States)

    Milanesi, L.; Pilotti, M.; Ranzi, R.; Valerio, G.

    2014-09-01

    Hydraulic hazards in alluvial fan areas are mainly related to torrential floods and debris flows. These processes are characterized by their fast time evolution and relevant sediment load. Rational approaches for the estimation of hazard levels in flood-prone areas make use of the maps of depth and velocity, which are provided by numerical simulations of the event. This paper focuses on national regulations regarding quantitative debris-flow hazard mapping and compares them to a simple conceptual model for the quantification of the hazard levels on the basis of human stability in a flood. In particular, the proposed method takes into account, in a conceptual fashion, both the local slope and the density of the fluid, that are crucial aspects affecting stability for processes in mountain environments. Physically-based hazard criteria provide more comprehensible and objective maps, increasing awareness among stakeholders and providing more acceptable constraints for land planning.

  1. Alluvial Fan Morphology, distribution and formation on Titan

    Science.gov (United States)

    Birch, S. P. D.; Hayes, A. G.; Howard, A. D.; Moore, J. M.; Radebaugh, J.

    2016-05-01

    Titan is a hydrologically active world, with dozens of alluvial fans that are evidence of sediment transport from high to low elevations. However, the distribution and requirements for the formation of fans on Titan are not well understood. We performed the first global survey of alluvial fans on Titan using Cassini Synthetic Aperture Radar (SAR) data, which cover 61% of Titan's surface. We identified 82 fans with areas ranging from 28 km2 to 27,000 km2. A significant fraction (∼60%) of the fans are restricted to latitudes of ±50-80°, suggesting that fluvial sediment transport may have been concentrated in the near-polar terrains in the geologically recent past. The density of fans is also found to be correlated with the latitudes predicted to have the highest precipitation rates by Titan Global Circulation Models. In equatorial regions, observable fans are not generally found in proximity to dune fields. Such observations suggest that sediment transport in these areas is dominated by aeolian transport mechanisms, though with some degree of recent equatorial fluvial activity. The fan area-drainage area relationship on Titan is more similar to that on Earth than on Mars, suggesting that the fans on Titan are smaller than what may be expected, and that the transport of bedload sediment is limited. We hypothesize that this has led to the development of a coarse gravel-lag deposit over much of Titan's surface. Such a model explains both the morphology of the fans and their latitudinal concentration, yielding insight into the sediment transport regimes that operate across Titan today.

  2. Charcoal and the Record of Fire-related Sedimentation in Holocene Alluvial Sediments

    Science.gov (United States)

    Meyer, G. A.

    2006-12-01

    Over the last few decades, rising temperatures and ensuing severe wildfires in the western USA cordillera have provided the opportunity to examine processes and deposits of postfire sedimentation on alluvial fans and floodplains. Most events are generated by widespread surface runoff from intense convective-storm precipitation on severely burned slopes. Flow processes range from debris flow to sediment-charged water floods. Muddy debris flows best preserve coarse charcoal in fan deposits, whereas gravelly debris flows often comminute charcoal into fine particles. As charcoal remains suspended in high-energy hyperconcentrated and water floods, only their fine-grained deposits typically contain much charcoal. Charcoal is locally concentrated in low-energy fluvial deposits, but displays increasing evidence for reworking with distance from source. Charred vegetation and litter marking burned soil surfaces may be preserved under postfire fan and fluvial sediments. Modern deposits provide models for identification of Holocene fire-related sediments and estimates of paleofire severity. AMS 14C dating of discrete charcoal fragments allows sample selection to minimize errors of sample age > fire age. Fires are incompletely recorded in the event stratigraphy of one fan, but larger populations of 14C ages from numerous fans permit composite probability distributions that represent centennial- to millennial-scale changes in fire-related sedimentation across a study area. Records from Yellowstone and central Idaho indicate the large role of fire in episodic erosion across a range of conifer forests, most strongly during severe, multidecadal droughts in warmer periods (e.g. in Medieval time 900-1300 AD). In central Idaho, identification of charcoal macrofossils indicates broadly similar, aspect-controlled forest compositions over the last 3000 yr. Emerging data from the Sacramento Mountains, New Mexico, show rapid fan aggradation due to fire-related events in the warm middle

  3. Soils of floodplains in arid regions of Inner Asia (the Zavkhan River, Mongolia)

    Science.gov (United States)

    Ubugunov, L. L.; Ubugunova, V. I.

    2012-03-01

    The environmental conditions of soil formation and the diversity and classification position of soils developing on the Zavkhan River floodplain are considered, and the morphogenetic and agrochemical properties of these soils are characterized. It is shown that the conditions of soil formation on the floodplain of the Zavkhan River are specified by the mountainous topography, the effect of the large Mongol Els sand massif, the character of the alluviation processes, the groundwater level and salinity, and the regime of floods. The position of the floodplain in the system of altitudinal zones largely dictates the character of the soil cover pattern. In terms of the new Russian soil classification system, the soils studied belong to three trunks, four orders, and seven types: stratified humus alluvial soils, light-humus alluvial soils, light-humus quasigley alluvial soils, light-humus stratozems, and solonchaks. The soils of floodplain ecosystems in arid regions are characterized by low fertility. For their efficient use for pasturing and crop growing, the ecologically balanced differentiated application of manure, mineral fertilizers (NPK), and some microelements is required.

  4. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2.

    Science.gov (United States)

    Chang Chien, S W; Chang, C H; Chen, S H; Wang, M C; Madhava Rao, M; Satya Veni, S

    2011-09-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO(2) in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO(2) was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO(2)) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO(2) and the photooxidation (without TiO(2)) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO(2)-enhanced photocatalytic pyrene degradation and in photooxidation (without TiO(2)) of pyrene. The percentages of photocatalytic pyrene degradation by TiO(2) in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO(2)-enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand>red soil>alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO(2)-enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO(2)) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO(2)-enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated. PMID:21762957

  5. Water dynamics and physical characteristics of hydromorphic soils in southern Bačka

    OpenAIRE

    PEKEČ, SAŠA; Vrbek, Boris; Orlović, Saša; Ballian, Dalibor

    2013-01-01

    Background and Purpose: The s tudy presents basic types of hydromorphic soils in a protected area of middle part of the Danube alluvial plain in Vojvodina. The Danube is the largest river in the Republic of Serbia. This is the first river which itself created an alluvial plain through the Pannonian plain. Due to the mild decrease of river bed slope and lateral erosion, which is a characteristic of lowland rivers, it formed a large dry alluvial plain. It was formed during the Holocene by alter...

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

    Science.gov (United States)

    Gran, K. B.

    2015-12-01

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

  7. Mississippi River Valley Alluvial Aquifer, Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Tennessee; 2006-2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Outcrop and subcrop extent of the Mississippi River Valley Alluvial Aquifer in Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, and Tennessee.

  8. Abundance and conservation of waste rice for wintering waterfowl in the Mississippi Alluvial Valley

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Flooded rice fields are important foraging habitats for wintering waterfowl in the Mississippi Alluvial Valley MAV. Abundant waste rice in early winter once existed...

  9. The Alluvial Fan Complex in Holden Crater: Implications for the Environment of Early Mars

    Science.gov (United States)

    Irwin, R. P.; Grant, J. A.; Howard, A. D.

    2008-03-01

    The alluvial fan complex in Holden crater is the largest deposit of this type on Mars and preserves topographic and sedimentary indicators of its formative environment around the Noachian/Hesperian transition.

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

    Science.gov (United States)

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

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

  11. Ground-water quality in alluvial aquifers in the eastern Iowa basins, Iowa and Minnesota

    Science.gov (United States)

    Sadorf, Eric M.; Linhart, S. Michael

    2000-01-01

    The quality of shallow alluvial ground water that is used for domestic supplies in the Wapsipinicon, Cedar, Iowa, and Skunk River Basins (Eastern Iowa Basins) is described. Water samples from 32 domestic-supply wells were collected from June through July 1998. This study of ground-water quality in alluvial aquifers in the Eastern Iowa Basins is part of the U.S. Geological Survey's National Water-Quality Assessment Program.

  12. Hydrological connectivity of alluvial Andean valleys: a groundwater/surface-water interaction case study in Ecuador

    Science.gov (United States)

    Guzmán, Pablo; Anibas, Christian; Batelaan, Okke; Huysmans, Marijke; Wyseure, Guido

    2016-06-01

    The Andean region is characterized by important intramontane alluvial and glacial valleys; a typical example is the Tarqui alluvial plain, Ecuador. Such valley plains are densely populated and/or very attractive for urban and infrastructural development. Their aquifers offer opportunities for the required water resources. Groundwater/surface-water (GW-SW) interaction generally entails recharge to or discharge from the aquifer, dependent on the hydraulic connection between surface water and groundwater. Since GW-SW interaction in Andean catchments has hardly been addressed, the objectives of this study are to investigate GW-SW interaction in the Tarqui alluvial plain and to understand the role of the morphology of the alluvial valley in the hydrological response and in the hydrological connection between hillslopes and the aquifers in the valley floor. This study is based on extensive field measurements, groundwater-flow modelling and the application of temperature as a groundwater tracer. Results show that the morphological conditions of a valley influence GW-SW interaction. Gaining and losing river sections are observed in narrow and wide alluvial valley sections, respectively. Modelling shows a strong hydrological connectivity between the hillslopes and the alluvial valley; up to 92 % of recharge of the alluvial deposits originates from lateral flow from the hillslopes. The alluvial plain forms a buffer or transition zone for the river as it sustains a gradual flow from the hills to the river. Future land-use planning and development should include concepts discussed in this study, such as hydrological connectivity, in order to better evaluate impact assessments on water resources and aquatic ecosystems.

  13. Heat tracer test in an alluvial aquifer: field experiment and inverse modelling

    OpenAIRE

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

    2016-01-01

    Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in...

  14. A heat and dye tracer test for characterizing and modelling heat transfer in an alluvial aquifer

    OpenAIRE

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

    2014-01-01

    Using heat as an active tracer is a topic of increasing interest with regards to characterizing shallow aquifers for ATES (Aquifer Thermal Energy Storage) systems. In this study, we investigate the potential interest of coupling simultaneous heat and dye tracer injection tests for characterization of an alluvial aquifer. The study site is located near Liege in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye ...

  15. Heat tracer and solute tests in an alluvial aquifer: field experiment and inverse modelling

    OpenAIRE

    Dassargues, Alain; Klepikova, Maria; Jamin, Pierre; Orban, Philippe; Brouyère, Serge

    2015-01-01

    Using heat as an active tracer in different types of aquifers is a topic of increasing interest. In this study, we investigate the potential interest of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer conce...

  16. The role of alluvial valley deposits in groundwater–surface water exchange in a Chalk river

    OpenAIRE

    Abesser, Corinna; Shand, Paul; Gooddy, Daren; Peach, Denis

    2008-01-01

    To understand the processes of surface water–groundwater exchange in Chalk catchments, a detailed hydrogeochemical study was carried out in the Lambourn catchment in southeast England. Monthly monitoring of river flow and groundwater levels and water chemistry has highlighted a large degree of heterogeneity at the river-corridor scale. The data suggest an irregular connection between the river, the alluvial deposits, and the Chalk aquifer at the study site. The groundwaters in the alluvial gr...

  17. Statistic inversion of multi-zone transition probability models for aquifer characterization in alluvial fans

    OpenAIRE

    Zhu, Lin; Dai, Zhenxue; Gong, Huili; Gable, Carl; Teatini, Pietro

    2015-01-01

    Understanding the heterogeneity arising from the complex architecture of sedimentary sequences in alluvial fans is challenging. This paper develops a statistical inverse framework in a multi-zone transition probability approach for characterizing the heterogeneity in alluvial fans. An analytical solution of the transition probability matrix is used to define the statistical relationships among different hydrofacies and their mean lengths, integral scales, and volumetric proportions. A statist...

  18. 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.

  19. Late Pleistocene eolian-alluvial interference in the Balearic Islands (Western Mediterranean)

    Science.gov (United States)

    Pomar, Francisco; Del Valle, Laura; Fornós, Joan J.; Gómez-Pujol, Lluís; Anechitei-Deacu, Valentina; Timar-Gabor, Alida

    2016-04-01

    This study deals with alluvial fan and aeolian sediments interference. Although initially they are two different environments, with different processes and resulting forms, very often their interaction produces deposits that share characteristics and features from both environments, as well as, maintain inherited elements from one to each other. In this sense, the aeolian-alluvial interference is the geomorphological expression of the coincidence, disruption and/or overlapping of aeolian and alluvial environments. Climate appears to be one of the most important controls on the role and magnitude of each environment in terms of sediment supply, precipitation, runoff or aeolian transport. In this study, eight major sedimentary facies have been described involving the succession of coastal, aeolian, colluvial and alluvial environments. Carbonate sandstones, breccias, conglomerates and fine-grained deposits are the main component of these sequences. OSL dating of aeolian levels indicate that their deposition took place during the Late Pleistocene, establishing a paleoclimatic evolution of Balearic coastal areas during the last 125 ka. The sedimentological and chronological analysis of these deposits allows reconstructing the coastal environmental changes during the Late Pleistocene at the Balearic archipelago. Keywords: Alluvial sedimentation, eolian sedimentation, alluvial-eolian interference, sea level, Late Pleistocene, Balearic Islands.

  20. Effects of Nitrogen Fertilizer on Grow th and Water U se Efficiency of M aize in Sandy-loam Alluvial Soil%氮肥施用量对砂壤质潮土玉米生长及水分利用效率的影响

    Institute of Scientific and Technical Information of China (English)

    杨永辉; 武继承; 王洪庆; 赵丽君; 郭庆

    2013-01-01

    In order to ascertain the characteristics of growth and water utilization of maize under different amount of nitrogen fertilizer ,a field experiment was conducted to investigate the effect of nitrogen fertilizer with dosage of 0 kg/ha (CK) ,90 kg/ha (N1) ,180 kg/ha(N2) ,270 kg/ha (N3) ,360 kg/ha(N4) ,450 kg/ha(N5) ,540 kg/ha(N6)on soil moisture ,maize agronomic charac-ters ,production elements ,yield and water utilization .The results indicated that application of ni-trogen fertilizer ,especially 450 kg/ha increased the upper soil water content ,and promted the maize root deep growth ,so the maize could rse more deep soil water .The corn morphological inde-xes of the treatment with 450 kg/ha nitrogen in different grow th period had better performance , and the production elements such as ear length ,ear coarse ,ear number of rows ,row grains were higher compared with CK .With the increase of nitrogen rate ,maize yield increased significantly , but when nitrogen fertilizer was higher than 450 kg/ha ,the increase rate of maize yield decreased obviously .And water use efficiency first increased and then dropped with the increase of nitrogen . The water use efficiency (WUE) of the treatment with 450 kg/ha nitrogen was highest and the yield (12 093 .0 kg/ha)and WUE ([24 .4 kg/(mm · hm2 )]) were 70 .7% and 78 .1% higher than CK .It was concluded that the treatment with 450 kg/ha nitrogen was the most promising option .%为探明氮肥施用量对玉米生长及水分利用的影响,采用田间试验研究了氮肥不同用量[N0(对照):0 kg/hm2、N1:90 kg/hm2、N2:180 kg/hm2、N3:270 kg/hm2、N4:360 kg/hm2、N5:450 kg/hm2、N6:540 kg/hm2]对玉米不同生育期土壤水分、农艺性状、成产要素、产量及水分利用的影响。结果表明,总体上,施用氮肥尤其是N5处理增加了上层土壤的含水率,并促进了玉米根系下扎深度,使玉米利用了较多的深层土壤水;在不同生育期,以N5和N6处

  1. The diffraction of Rayleigh waves by a fluid-saturated alluvial valley in a poroelastic half-space modeled by MFS

    Science.gov (United States)

    Liu, Zhongxian; Liang, Jianwen; Wu, Chengqing

    2016-06-01

    Two dimensional diffraction of Rayleigh waves by a fluid-saturated poroelastic alluvial valley of arbitrary shape in a poroelastic half-space is investigated using the method of fundamental solutions (MFS). To satisfy the free surface boundary conditions exactly, Green's functions of compressional (PI and PII) and shear (SV) wave sources buried in a fluid-saturated poroelastic half-space are adopted. Next, the procedure for solving the scattering wave field is presented. It is verified that the MFS is of excellent accuracy and numerical stability. Numerical results illustrate that the dynamic response strongly depends on such factors as the incident frequency, the porosity of alluvium, the boundary drainage condition, and the valley shape. There is a significant difference between the diffraction of Rayleigh waves for the saturated soil case and for the corresponding dry soil case. The wave focusing effect both on the displacement and pore pressure can be observed inside the alluvial valley and the amplification effect seems most obvious in the case of higher porosity and lower frequency. Additionally, special attention should also be paid to the concentration of pore pressure, which is closely related to the site liquefaction in earthquakes.

  2. Spatial variability in bank resistance to erosion on a large meandering, mixed bedrock-alluvial river

    Science.gov (United States)

    Konsoer, Kory M.; Rhoads, Bruce L.; Langendoen, Eddy J.; Best, James L.; Ursic, Mick E.; Abad, Jorge D.; Garcia, Marcelo H.

    2016-01-01

    Spatial heterogeneity in the erosion-resistance properties of the channel banks and floodplains associated with sediment characteristics, vegetation, or bedrock can have a substantial influence on the morphodynamics of meandering rivers, resulting in highly variable rates of bank erosion and complex patterns of planform evolution. Although past studies have examined the spatial variability in bank erodibility within small rivers, this aspect of the erosion-resistance properties for large rivers remains poorly understood. Furthermore, with the exception of recent numerical modeling that incorporates stochastic variability of floodplain erosional resistance, most models of meandering river dynamics have assumed uniform erodibility of the bank and floodplain materials. The present paper investigates the lateral and vertical heterogeneity in bank material properties and riparian vegetation within two elongate meander loops on a large mixed bedrock-alluvial river using several geotechnical field and laboratory methods. Additionally, the bank stability and toe-erosion numerical model (BSTEM) and repeat terrestrial LiDAR surveys are used to evaluate the capacity of the bank material properties to modify the rates and mechanisms of bank retreat. Results show that the textural properties of the bank materials, soil cohesion, and critical shear stress necessary for sediment entrainment differ substantially between the two bends and are also highly variable within each bend - laterally and vertically. Trees growing along the banks increase the resistance to erosion by contributing to the shear strength of the bank materials and are capable of increasing bank stability along a large river. Locally outcropping bedrock also influences bank erodibility in both bends. The results of this study demonstrate that spatial variability in the erosion-resistance properties of the channel banks is an important factor contributing to spatial variability in the rates and mechanisms of bank

  3. Lower Eocene alluvial paleosols (Willwood Formation, Northwest Wyoming, U.S.A.) and their significance for paleoecology, paleoclimatology, and basin analysis

    Science.gov (United States)

    Bown, T.M.; Kraus, M.J.

    1981-01-01

    The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed. Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless. All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency

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

    Science.gov (United States)

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

    1999-01-01

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

  5. Mass Transport within Soils

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.

    2009-03-01

    Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated

  6. Geotechnical mapping for alluvial fan deposits controlled by active faults: a case study in the Erzurum, NE Turkey

    Science.gov (United States)

    Yarbasi, Necmi; Kalkan, Ekrem

    2009-08-01

    Erzurum, the biggest city of Eastern Anatolia Region in the Turkey, is located in Karasu Plain. Karasu Plain, located on the central segment of the Erzurum Fault Zone, is an intermountain sedimentary basin with a Miocene-Quaternary volcanic basement, andesitic-basaltic lava flows and fissure eruptions of basaltic lava. It was filled in the early Quaternary by lacustrine fan-delta deposits. The basin is characterized by NNE-SSW trending sinistral wrench faults on its eastern margin and ENE-WSW trending reverse faults on its southern margin. Both systems of active faults intersect very near to Erzurum, which is considered to be the most likely site for the epicenter of a probable future large earthquake. Historical records of destructive earthquakes, morphotectonic features formed by paleo-seismic events and instrument seismic data of region indicate to a very high regional seismicity. The residential areas of Erzurum are located on thick alluvial fan deposits forming under the control of faults on the central segment of the Erzurum Fault Zone, which is one of the most active fault belts of the East Anatolian Region. Over time, the housing estates of city such as Yenisehir and Yildizkent have been expanded toward to the west and southwest part of Erzurum as a consequence of rapid and massive construction during the last 30 years. Geotechnical investigation has therefore been undertaken the residential areas of city in order to characterize geotechnical properties over the varied lithologies examine the potential for geotechnical mapping and assess the foundation conditions of the present and future settlement areas. The geological field observations and operations have been performed to make the soil sampling and characterize the lateral and vertical changes in thickness of the alluvial deposits in trenches, excavations and deep holes with 6-12 m sections. The soil samples have been subjected to a series of tests under laboratory conditions to obtain physical and

  7. IBIEM modelling of the amplification of seismic waves by a three-dimensional layered alluvial basin

    Science.gov (United States)

    Liu, Zhongxian; Liang, Jianwen; Huang, Yihe; Liu, Lei

    2016-02-01

    We develop an indirect boundary integral equation method (IBIEM) to solve the scattering of seismic waves by a 3-D layered alluvial basin. We adopt the dynamic Green's functions for concentrated loads for a layered half-space derived from the modified stiffness method. This new algorithm of Green's function can solve the near-source response efficiently and accurately, and also facilitates the meshless implementation of the IBIEM. The numerical accuracy and stability of the IBIEM are tested for a homogeneous, hemispherical alluvial basin, and a two-layered model. Based on the IBIEM, the effects of several important parameters, such as the incident frequency, the angle of incidence and the properties of the alluvial layers are investigated for incident plane P and SV waves, respectively. The results show that the local amplification effects of a 3-D layered alluvial basin on the ground motion are strikingly significant, and that the spatial variation of the displacement response is drastic. We also find that the thickness of the near-surface low-velocity alluvial layer has a pronounced influence on the frequency spectrum of ground motion within the basin. As for the thick low-velocity layer, the amplification effect on the displacement amplitude spectrum appears in a wide range of frequencies, with more resonant models in the same frequency range. As for the thin low-velocity layer, in contrast, the amplification effect is close to the homogeneous case but becomes more significant for high-frequency waves. The displacement amplification for a basin with a soft intermediate layer is larger than that of the homogeneous basin for the lower frequencies, but seems to be weakened for high-frequency waves. Additionally, the damping ratio of the alluvial layer can substantially reduce the displacement amplitude in the basin, especially in the range of resonant frequencies. Our results provide a better understanding of the 3-D wave focusing and basin-edge effect within 3-D

  8. Phosphate Treatment of Lead-Contaminated Soil: Effects on Water Quality, Plant Uptake, and Lead Speciation

    Science.gov (United States)

    Water quality threats associated with using phosphate-based amendments to remediate Pb-contaminated soils are a concern, particularly in riparian areas. This study investigated the effects of P application rates to a Pb-contaminated alluvial soil on Pb and P loss via surface wat...

  9. Groundwater Dynamics in Drained Soils of the Biđ-fi eld District

    OpenAIRE

    Ivan Mustać; Dragutin Petošić; Goran Gjetvaj; Vilim Filipović

    2011-01-01

    The main goal of five-year stationary investigations (2001-2006) was to assess groundwater dynamics in the Biđ-field district, as well as the type of soil moistening of agricultural soils spreading over 5838 ha. Detailed hydropedological investigations were carried out in 2000 and a soil map of the region was produced (scale = 1:10000) using universal kriging. Soil investigations identified six pedosystematic units: alluvial-gley, semigley-pseudogley, eugley hypogley, humogley, eugley amphigl...

  10. Nutrients, Trace Elements and Water Deficit in Greek Soils Cultivated with Olive Trees

    OpenAIRE

    Theodore Karyotis; George Arampatzis; Andreas Panagopoulos; Evangelos Hatzigiannakis; Evangelos Tziritis; Katerina Karyoti; John Vrouchakis

    2014-01-01

    The studied soils consist of alluvial and/or colluvial deposits  located in the Prefecture of Messinia, Western Peloponnese (Greece). A total number of 263 surface soil layers were selected and analysed for the main properties. Minimum and maximum values and  the distribution of soil properties varied greatly and can be attributed mainly to various fertilization practices adopted by  farmers, inputs of nutrients by irrigation water and differences due to inherent soil conditions. Lower variab...

  11. Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

    Science.gov (United States)

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

    2014-01-01

    Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak (Quercus lyrata) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry (Celtis laevigata) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually

  12. Distribution of bedrock and alluvial channels in forested mountain drainage basins

    Science.gov (United States)

    Montgomery, David R.; Abbe, Tim B.; Buffington, John M.; Peterson, N. Phil; Schmidt, Kevin M.; Stock, Jonathan D.

    1996-06-01

    MOUNTAIN river networks often consist of both bedrock and alluvial channels1-5, the spatial distribution of which controls several fundamental geomorphological and ecological processes6,7. The nature of river channels can influence the rates of river incision and landscape evolution1,2, as well as the stream habitat characteristics affecting species abundance and aquatic ecosystem structure8-11. Studies of the factors controlling the distribution of bedrock and alluvial channels have hitherto been limited to anthropogenic badlands12. Here we investigate the distribution of channel types in forested mountain drainage basins, and show that the occurrence of bedrock and alluvial channels can be described by a threshold model relating local sediment transport capacity to sediment supply. In addition, we find that valley-spanning log jams create alluvial channels- hospitable to aquatic life-in what would otherwise be bedrock reaches. The formation of such jams depends critically on the stabilizing presence of logs derived from the largest trees in the riverside forests, suggesting that management strategies that allow harvesting of such trees can have a devastating influence on alluvial habitats in mountain drainage basins.

  13. Conditions for tidal bore formation in convergent alluvial estuaries

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  15. Hydrogeomorphic processes and torrent control works on a large alluvial fan in the eastern Italian Alps

    Directory of Open Access Journals (Sweden)

    L. Marchi

    2010-03-01

    Full Text Available Alluvial fans are often present at the outlet of small drainage basins in alpine valleys; their formation is due to sediment transport associated with flash floods and debris flows. Alluvial fans are preferred sites for human settlements and are frequently crossed by transport routes. In order to reduce the risk for economic activities located on or near the fan and prevent loss of lives due to floods and debris flows, torrent control works have been extensively carried out on many alpine alluvial fans. Hazard management on alluvial fans in alpine regions is dependent upon reliable procedures to evaluate variations in the frequency and severity of hydrogeomorphic processes and the long-term performance of the torrent training works. An integrated approach to the analysis of hydrogeomorphic processes and their interactions with torrent control works has been applied to a large alluvial fan in the southern Carnic Alps (northeastern Italy. Study methods encompass field observations, interpretation of aerial photographs, analysis of historical documents, and numerical modelling of debris flows. The overall performance of control works implemented in the early decades of 20th century was satisfactory, and a reduction of hazardous events was recognised from features observed in the field and in aerial photographs, as well as from the analysis of historical records. The 2-D simulation of debris flows confirms these findings, indicating that debris flow deposition would not affect urban areas or main roads, even in the case of a high-magnitude event. Present issues in the management of the studied alluvial fan are representative of situations frequently found in the European Alps and deal with the need for maintenance of the control structures and the pressures for land use changes aimed at the economic exploitation of the fan surface.

  16. Impact of sedimentary heterogenities and sinuosity on river -aquifer exchanges in a meandering alluvial plain.

    Science.gov (United States)

    Rivière, A.; Maillot, M.; Weill, P.; Goblet, P.; Ors, F.

    2015-12-01

    A coupled sedimentary and hydrogeological model is used to quantify the impact of sedimentary heterogeneities and sinuosity on groundwater fluxes in an alluvial plain deposited by a meandering fluvial system. A 3D heterogeneous alluvial plain model is built with the stochastic/process-based model FLUMY, that simulates the evolution and the sedimentary processes of a meandering channel and its associated deposits. The resulting sedimentary blocks are translated in terms of hydrodynamic parameters (hydrofacies) and used in the 3D transient water transport model METIS. The simulated domain is 10 m-thick and at a pluri-kilometric horizontal scale, allowing considering several meanders. A head gradient between the upstream and downstream limits is imposed. The river is considered as a constant-head boundary that decreases linearly along the channel centerline. A zero-flux condition is prescribed on the other boundaries. Several cases are studied, including different degrees of sinuosity and different configurations of sediment heterogeneity: (i) a homogeneous sandy aquifer (ii) single mud-filled oxbow lake in a sandy porous media, (iii) several mud-filled oxbow lakes in a sandy porous media, and (iv) "fully" heterogeneous alluvial plain including fine-grained overbank deposits, sandy point bars, mudplugs and sandy crevasse plays. We quantify the exchange rates and directions between the river and the aquifer along the channel centerline, the piezometric evolution and the water residence time in the heterogeneous alluvial plain. This original method can improve our understanding of the functioning of alluvial corridors and evaluate the relevance of taking into account the structural heterogeneity of alluvial plains in larger regional hydrogeological models.

  17. Morphometry and Geomorphic Characteristics of Large Alluvial fans and Megafans in South America

    Science.gov (United States)

    Latrubesse, E. M.; Sounny-Slitine, M. A.

    2015-12-01

    Alluvial megafans are 'large' fan-shaped bodies of sediment that form from lateral migrations of a river as it exits a topographic front. They differ from large alluvial fans (radial length between 30-100km) with sizes greater than 100-km in radial length. This study characterizes and describes megafans and large alluvial fan through morphometrics. We cataloged the fans into a geodatabase delineating size and extent of basins both upstream and downstream from the apex. Through remote sensing, elevation modeling and geomorphic mapping, we populated the database with fan morphometric measurements, qualitative descriptions and basin parameters. Metrics include planform area, catchment area, gradient, relief index, drainage density, and others. These were compared to longitudinal/transverse profiles, satellite imagery, and geomorphic maps. The database is global, however since the largest megafans of the world are located in South America, this preliminary analysis will focus on the continent. We found morphometric and characteristic differences between large alluvial fans and megafans in the region. These include difference in relationship between morphometrics, for example the ratio between catchment and fan size area. These properties of fans could be a better approach in differentiating megafans from large alluvial fans. The current criteria is an artificial scale divide, which varies in the literature, with the most common being a 100-km apex-to-toe length. Alternative values as little of 30-km apex-to-toe length have been proposed, as well as alternative metrics like coverage areas of greater than 10,000 square-km. We propose that geomorphic characteristics and morphometrics provide an intrinsic approach to differentiating megafans from larger alluvial fans.

  18. Experimental alluvial fans: Advances in understanding of fan dynamics and processes

    Science.gov (United States)

    Clarke, Lucy E.

    2015-09-01

    Alluvial fans are depositional systems that develop because of a disparity between the upstream and downstream sediment transport capacity of a system, usually at the base of mountain fronts as rivers emerge from the constrained mountain area onto the plain. They are dynamic landforms that are prone to abrupt changes on a geomorphological (decades to centuries) time scale, while also being long-term deposition features that preserve sedimentary strata and are sensitive indictors of environmental change. The complexity of interactions between catchment characteristics, climate, tectonics, internal system feedbacks, and environmental processes on field alluvial fans means that it is difficult to isolate individual variables in a field setting; therefore, the controlled conditions afforded by experimental models has provided a novel technique to overcome some of these complexities. The use of experimental models of alluvial fans has a long history and these have been implemented over a range of different research areas utilising various experimental designs. Using this technique, important advances have been made in determining the primary factors influencing fan slope, understanding of avulsion dynamics, identifying autogenic processes driving change on fan systems independent of any change in external conditions, and the mechanics of flow and flood risk on alluvial fans, to name a few. However, experiments cannot be carried out in isolation. Thus, combining the findings from experimental alluvial fans with field research and numerical modelling is important and, likewise, using these techniques to inform experimental design. If this can be achieved, there is potential for future experimental developments to explore key alluvial fan issues such as stratigraphic preservation potential and simulating extra terrestrial fan systems.

  19. Occurrence of volcanic ash in the Quaternary alluvial deposits, lower Narmada basin, western India

    Indian Academy of Sciences (India)

    Rachna Raj

    2008-02-01

    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 been correlated with the Youngest Toba Tuff. The finding of ash layer interbedded in Quaternary alluvial sequences of western Indian continental margin is significant, as ash being datable material, a near precise time-controlled stratigraphy can be interpreted for the Quaternary sediments of western India. The distant volcanic source of this ash requires a fresh re-assessment of ash volume and palaeoclimatic interpretations.

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

    OpenAIRE

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

    2007-01-01

    An alluvial aquifer can be described as a groundwater system, generally unconfined, that is hosted in laterally discontinuous layers of gravel, sand, silt and clay, deposited by a river in a river channel, banks or flood plain. In semi-arid regions, streams that are associated with alluvial aquifers tend to vary from discharge water bodies in the dry season, to recharge water bodies during certain times of the rainy season or when there is flow in the river from managed reservoir releases. Al...

  1. Decomposition of Organic Substrates and their Effect on Mungbean Growth in Two Soils of the Mekong Delta

    Directory of Open Access Journals (Sweden)

    Mathias Becker

    2008-04-01

    Full Text Available Agricultural land use in the Mekong Delta of Vietnam is dominated by intensive irrigated rice cropping systems on both alluvial and acid sulfate soils. A stagnating and occasionally declining productivity may be linked on the alluvial soils to low N use efficiency and low soil organic matter content while on acid sulfate soils to acidity, Al toxicity and P deficiency. For economic reasons, farmers increasingly diversify their cropping system by replacing the dry season rice by high-value horticultural crops grown under upland conditions. However, upland cropping is likely to further exacerbate the soil-related problems. Organic substrates from decentralized waste and waste water management are widely available and may help to alleviate the reported soil problems. During the dry season of 2003/2004, the effect of the application of various types and rates of locally available waste products on crop performance was evaluated at both an alluvial and an acid sulfate soil site. The C and N mineralization dynamics of nine organic substrates from waste and waste water treatment were determined by anaerobic (N and aerobic (C incubation in the laboratory. The response of 12 week-old mungbean (dry matter accumulation to substrate application (1.5 – 6.0 Mg ha−1 was evaluated on a degraded alluvial and on an acid sulfate soil. In the alluvial soil, largest mineralization rates were observed from anaerobic sludge. Biomass increases in 12 week-old mungbean ranged from 25-98% above the unfertilized control. In the acid sulfate soil, highest net-N release rates were observed from aerobic composts with high P content. Mungbean biomass was related to soil pH and exchangeable Al3+ and was highest with the application of aerobic composts. We conclude that the use of organic substrates in the rice-based systems of the Mekong Delta needs to be soil specific.

  2. WORK OF COMBINED LARGE DIAMETER PIPE (SLURRY PIPELINE) ON ALLUVIAL SOILS TAILING HGF

    OpenAIRE

    A. O. Hurzhij

    2015-01-01

    The research results of influence of the deformation of tailing-dump dams on the sludge lines are considered. In designing the routes of sludge lines, it is offered to calculate the base deformations under the sludge line to substantiate the anti-destruction protection of sludge lines.

  3. A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity

    Science.gov (United States)

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

    2011-01-01

    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.

  4. Deducing Weathering Processes Using Silicon Isotopes in the Ganges Alluvial Plain, India

    Science.gov (United States)

    Frings, P.; De La Rocha, C. L.; Fontorbe, G.; Chakrapani, G.; Clymans, W.; Conley, D. J.

    2014-12-01

    The Ganges Alluvial Plain ('GAP') is the sedimentary infill of the foreland basin created during Himalayan orogeny. Freshly eroded material from the Himalaya and southern cratonic tributaries is deposited into a system with long water-sediment interaction times, creating potential for further generation of river weathering fluxes. To quantify weathering processes in the GAP, 51 sites including all major tributaries were sampled in a September 2013 campaign and analysed for major and minor ions, Ge/Si ratios and δ30Si, δ13C and δ18O. Net dissolved Si (DSi) and major cation yields are 2 to 5 times lower in the GAP than the Himalaya, and at a whole basin scale approximate the global average, indicating that the plain apparently moderates the efficiency of Himalayan weathering rates. Mainstem δ30Si spans 0.81 to 1.93‰ (see figure) and gives the impression of a system buffered to moderate DSi and δ30Si. Ge/Si ratios (µmol/mol) are higher than expected in the Himalaya (>3), reflecting input of Ge-enriched water from hot springs, and decline to ~1.4 in the GAP. For the Himalayan sourced rivers, δ30Si increases with distance from the Himalayan front, and can not be explained entirely by conservative mixing with higher δ30Si peninsular and GAP streams. To a first degree, the δ30Si data suggest incorporation of Si into secondary minerals as the key fractionating process, and that this occurs both in situ during initial weathering and progressively in the GAP. Partitioning of solutes between sources is complicated in the GAP. Consistent with previous work, carbonate weathering dominates the ion fluxes, but with substantial contributions from saline/alkaline soil salts, the chlorination of wastewater and highly variable rainfall chemistry. Due to these contributions, precisely inferring the input from silicate weathering is difficult. We introduce a novel method to infer silicate-weathering rates that exploits the fractionation of Si during clay formation to account

  5. Butachlor degradation in tropical soils: effect of application rate, biotic-abiotic interactions and soil conditions.

    Science.gov (United States)

    Pal, R; Das, P; Chakrabarti, K; Chakraborty, A; Chowdhury, A

    2006-01-01

    The degradative characteristics of butachlor (N-Butoxymethyl-2-chloro-2',6'-diethyla- cetanilide) were studied under controlled laboratory conditions in clay loam alluvial (AL) soil (Typic udifluvent) and coastal saline (CS) soil (Typic endoaquept) from rice cultivated fields. The application rates included field rate (FR), 2-times FR (2FR) and 10-times FR (10FR). The incubation study was carried out at 30 degrees C with and without decomposed cow manure (DCM) at 60% of maximum water holding capacity (WHC) and waterlogged soil condition. The half-life values depended on the soil types and initial concentrations of butachlor. Butachlor degraded faster in AL soil and in soil amended with DCM under waterlogged condition. Microbial degradation is the major avenue of butachlor degradation from soils.

  6. Soil survey of Solid Waste Storage Area 6

    International Nuclear Information System (INIS)

    An intensive soil survey was made of Solid Waste Storage Area (SWSA) 6 (Oak Ridge National Laboratory) at a scale of 1:1200. The amount of chemical weathering, the thickness of upland soils, and the depth to unoxidized rock are dependent on slope gradient, water-flow pathways, degree of rock fracturing, and the extent of soil and rock erosion by late Pleistocene and Holocene geomorphic processes. Foot-slope landforms have generally concave slope shapes where sediment accumulates. Colluvium stratigraphy exhibits at least one lithologic discontinuity, but there may be two discontinuities preserved in some thicker colluvia. One or more paleosols, either complete or partially truncated, are preserved in these concave landforms. Alluvial soils were not examined in detail but were separated from colluvial soils because of their wetness. A small area of ancient alluvium was located on a stable upland summit that formed the highest elevation in SWSA-6. On the nearly level summit, a thin loess cap was preserved on the older alluvial soil. Upland and colluvial soils are all highly leached and strongly acid even though they are formed from a calcareous parent rock. The highly fractured rock, being relatively permeable, has been leached free of carbonates in the upper levels so that there is a wide pH gradient from the surface downward. Most of the soils were classified as Ultisols, with minimal areas of Alfisols, Inceptisols, and Entisols. Based on the soil survey, representative landforms and soils will be selected to study physical, chemical, and mineralogical properties of the soil and weathered rock. Those properties will be used to predict both the amount and duration of leachate filtration and purification in downward migration to the water table or lateral migration through colluvial and alluvial soils to ground-water seeps

  7. Temperature Effect on Boron Adsorption—Desorption Kinetics in Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUDUANWEI; SHILEI; 等

    1999-01-01

    The effect of temperature on the properties of boron adsorption-desorption in brown-red soil,yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique.The experimental data of B adsorption-desorption amounts and reaction time at 25 and 40℃ were fitted by the zero-order,first-order and parabolic diffusion kinetic equations.The adsorption process was in conformity with the parabolic diffusion law at both the temperatures,and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138,0.124 and 0.105 mg kg-1 min-1/2 at 25℃,and 0.147,0.146and 0.135mg kg-1 min1/2 at 40℃ for the brown-red soil,yellow-brown soil,and calcareous alluvial soil,respectively,The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation,and the corresponding values of rate constant were 0.0422,0.0563 and 0.0384min-1 at 25℃,and 0.0408,0.0423 and 0.0401min-1 at 40℃ for the brown-red soil,the yellow-brown soil and the calcareous alluvial soil,respectively.Therefore,the desorption process of B might be related to the amount of B adsorbed in soil,The higher th temperature,the lower the amount of B adsorption of the same soil in the same reaction time,The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27,8.44 and 12.99 kJ mol-1,respectively,based on the experimental data of B adsorption amounts and reaction time at and 40℃.

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

    Directory of Open Access Journals (Sweden)

    Majkić-Dursun Brankica

    2015-01-01

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

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

    NARCIS (Netherlands)

    Hamer, de W.; Love, D.; Owen, R.; Booij, M.J.; Hoekstra, A.Y.

    2007-01-01

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

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

    NARCIS (Netherlands)

    Hamer, de W.; Love, D.; Owen, R.; Booij, M.J.; Hoekstra, A.Y.

    2008-01-01

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

  11. 75 FR 62137 - Notice of Public Meeting; Proposed Alluvial Valley Floor Coal Exchange Public Interest Factors...

    Science.gov (United States)

    2010-10-07

    ... written testimony and comments on the public interest factors (see determination of public interest at 43... final decision on the proposed exchange and whether it is in the public interest. The BLM will discuss... Bureau of Land Management Notice of Public Meeting; Proposed Alluvial Valley Floor Coal Exchange...

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

    Science.gov (United States)

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

    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

  15. Intrinsic steady alternate bars in alluvial channels. Part 1: experimental observations and numerical tests.

    NARCIS (Netherlands)

    Crosato, A.; Desta, F.B.

    2009-01-01

    Alternate bars in straight alluvial channels are migrating or steady. The currently accepted view is that they are steady only if the width-to-depth ratio is at the value of resonance or if the bars are forced by a steady local perturbation. Experimental observations, however, seem to indicate that

  16. NATURAL ARSENIC CONTAMINATION OF HOLOCENE ALLUVIAL AQUIFERS BY LINKED TECTONIC, WEATHERING, AND MICROBIAL PROCESSES

    Science.gov (United States)

    Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of...

  17. The recharge process in alluvial strip aquifers in arid Namibia and implication for artificial recharge

    Science.gov (United States)

    Sarma, Diganta; Xu, Yongxin

    2016-10-01

    Alluvial strip aquifers associated with ephemeral rivers are important groundwater supply sources that sustain numerous settlements and ecological systems in arid Namibia. More than 70 % of the population in the nation's western and southern regions depend on alluvial aquifers associated with ephemeral rivers. Under natural conditions, recharge occurs through infiltration during flood events. Due to the characteristic spatial and temporal variability of rainfall in arid regions, recharge is irregular making the aquifers challenging to manage sustainably and they are often overexploited. This condition is likely to become more acute with increasing water demand and climate change, and artificial recharge has been projected as the apparent means of increasing reliability of supply. The article explores, through a case study and numerical simulation, the processes controlling infiltration, significance of surface water and groundwater losses, and possible artificial recharge options. It is concluded that recharge processes in arid alluvial aquifers differ significantly from those processes in subhumid systems and viability of artificial recharge requires assessment through an understanding of the natural recharge process and losses from the aquifer. It is also established that in arid-region catchments, infiltration through the streambed occurs at rates dependent on factors such as antecedent conditions, flow rate, flow duration, channel morphology, and sediment texture and composition. The study provides an important reference for sustainable management of alluvial aquifer systems in similar regions.

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

    Directory of Open Access Journals (Sweden)

    P. Négrel

    2004-01-01

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

  19. An Alluvial Surface Chronology Based on Cosmogenic 36Cl Dating, Ajo Mountains (Organ Pipe Cactus National Monument), Southern Arizona

    Science.gov (United States)

    Liu, Beiling; Phillips, Fred M.; Pohl, Molly M.; Sharma, Pankaj

    1996-01-01

    A chronology of alluvial surfaces on piedmont slopes below the western Ajo Mountains, southern Arizona, has been obtained using cosmogenic 36Cl accumulation and AMS radiocarbon dating. The apparent 36Cl ages of individual boulders range from 520,000 to 13,000 yr, and the 14C ages of organic material in the two young terraces are 2750-2350 and 17,800 cal yr B.P. The sequence of 36Cl ages is consistent with the apparent stratigraphic order, but groupings of similar ages for different surfaces appear to result from repeated reworking of older surfaces associated with the deposition of younger ones. The youngest surface gave a distribution of 36Cl ages about 30,000 yr older than the 14C and soil ages; however, this distribution had 36Cl ages that overlapped with 36Cl ages from active channels and hillslopes. We attribute the older-than-expected exposure ages of sampled boulders to inheritance of 36Cl while residing near the surface during very slow erosion on the mountain front. Our results show that although cosmogenic nuclide accumulation can help establish chronologies for surfaces in piedmont settings, care must be used in evaluating the effects of complex exposure histories.

  20. Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley

    Science.gov (United States)

    Faulkner, Stephen P.; Baldwin, Michael J.; Barrow, Wylie C.; Waddle, Hardin; Keeland, Bobby D.; Walls, Susan C.; James, Dale; Moorman, Tom

    2010-01-01

    The Mississippi Alluvial Valley (MAV) is the Nation?s largest floodplain and this once predominantly forested ecosystem provided significant habitat for a diverse flora and fauna, sequestered carbon in trees and soil, and stored floodwater, sediments, and nutrients within the floodplain. This landscape has been substantially altered by the conversion of nearly 75% of the riparian forests, predominantly to agricultural cropland, with significant loss and degradation of important ecosystem services. Large-scale efforts have been employed to restore the forest and wetland resources and the U.S. Department of Agriculture (USDA) Wetlands Reserve Program (WRP) and Conservation Reserve Program (CRP) represent some of the most extensive restoration programs in the MAV. The objective of the WRP is to restore and protect the functions and values of wetlands in agricultural landscapes with an emphasis on habitat for migratory birds and wetland-dependent wildlife, protection and improvement of water quality, flood attenuation, ground water recharge, protection of native flora and fauna, and educational and scientific scholarship.

  1. Groundwater flow and transport modeling: A case study of alluvial aquifer in the Tuul River Basin, Mongolia

    Science.gov (United States)

    Dandar, Enkhbayar; Carrera, Jesús; Nemer, Buyankhishig

    2016-04-01

    The Tuul River basin is located northern Mongolia. It includes Ulaanbaatar city, which hosts 48% of Mongolian population. Water supply to the city relies exclusively on groundwater withdrawn from alluvial aquifers along the Tuul River Basin. Water demand of the city has increased recently as a result of rapid industrial development and population growth due to migration from rural areas. The aim of this study is to characterize the aquifer by integrating existing data in a flow model. Unfortunately, existing data are not sufficient for unequivocal identification of model parameters (groundwater recharge, permeability, lateral inflow, etc.). Fluctuations of water temperature have been recognized as a natural tracer that may be used for hydrogeological characterization and model calibration. Temperatures within the aquifer are affected by the temperature of inflowing water as well as by conduction from the soil surface, which we suspect may control aquifer temperatures. Properly acknowledging these fluctuations would require a three dimensional model. Instead, we propose a semianalytical solution based on the use of memory and influence functions.

  2. Provenance of alluvial fan deposits to constrain the mid-term offsets along a strike-slip active fault: the Elsinore fault in the Coyote Mountains, Imperial Valley, California.

    Science.gov (United States)

    Masana, Eulalia; Stepancikova, Petra; Rockwell, Thomas

    2013-04-01

    The lateral variation in rates along a fault and its constancy along time is a matter of discussion. To give light to this discussion, short, mid and long term offset distribution along a fault is needed. Many studies analyze the short-term offset distribution along a strike-slip fault that can be obtained by the analysis of offset features imprinted in the morphology of the near-fault area. We present an example on how to obtain the mid- to long-term offset values based on the composition of alluvial fans that are offset by the fault. The study area is on the southern tip of the Elsinore fault, which controls the mountain front of the Coyote Mountains (California). The Elsinore-Laguna Salada fault is part of the San Andreas fault (SAF) system, extending 250 km from the Los Angeles Basin southeastward into the Gulf of California, in Mexico. The slip-rate on the southern Elsinore fault is believed to be moderate based on recent InSAR observations, although a recent study near Fossil Canyon (southern Coyote Mountains) suggests a rate in the range of 1-2 mm/yr. For this study we processed the airborne LiDAR dataset (EarthScope Southern & Eastern California, SoCal) to map short to mid-term alluvial offsets. We reprocessed the point clouds to produce DEMs with 0.5m and 0.25m grids and we varied the insolation angles to illuminate the various fault strands and the offset features. We identified numerous offset features, such as rills, channel bars, channel walls, alluvial fans, beheaded channels and small erosional basins that varied in displacement from 1 to 350 m. For the mid- to long-term offsets of the alluvial fans we benefited from the diverse petrological composition of their sources. Moreover, we recognized that older alluvium, which is offset by greater amounts, is in some cases buried beneath younger alluvial fan deposits and separated by buried soils. To determine the source canyon of various alluvial elements, we quantified the clast assemblage of each source

  3. MODIFICATIONS ON THE SOILS MAP OF VINGA PLAIN DUE TO THE APPLICATION OF THE ROMANIAN SYSTEM OF SOIL TAXONOMY (RSST

    Directory of Open Access Journals (Sweden)

    C. Grigoras

    2005-10-01

    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.

  4. Alluvial and bedrock aquifers of the Denver Basin; eastern Colorado's dual ground-water resource

    Science.gov (United States)

    Robson, Stanley G.

    1989-01-01

    Large volumes of ground water are contained in alluvial and bedrock aquifers in the semiarid Denver basin of eastern Colorado. The bedrock aquifer, for example, contains 1.2 times as much water as Lake Erie of the Great Lakes, yet it supplies only about 9 percent of the ground water used in the basin. Although this seems to indicate underutilization of this valuable water supply, this is not necessarily the case, for many factors other than the volume of water in the aquifer affect the use of the aquifer. Such factors as climatic conditions, precipitation runoff, geology and water-yielding character of the aquifers, water-level conditions, volume of recharge and discharge, legal and economic constraints, and water-quality conditions can ultimately affect the decision to use ground water. Knowledge of the function and interaction of the various parts of this hydrologic system is important to the proper management and use of the ground-water resources of the region. The semiarid climatic conditions on the Colorado plains produce flash floods of short duration and large peak-flow rates. However, snowmelt runoff from the Rocky Mountains produces the largest volumes of water and is typically of longer duration with smaller peak-flow rates. The alluvial aquifer is recharged easily from both types of runoff and readily stores and transmits the water because it consists of relatively thin deposits of gravel, sand, and clay located in the valleys of principal streams. The bedrock aquifer is recharged less easily because of its greater thickness (as much as 3,000 feet) and prevalent layers of shale which retard the downward movement of water in the formations. Although the bedrock aquifer contains more than 50 times as much water in storage as the alluvial aquifer, it does not store and transmit water as readily as the alluvial aquifer. For example, about 91 percent of the water pumped from wells is obtained from the alluvial aquifer, yet water-level declines generally have

  5. Role of Fe-oxides for predicting phosphorus sorption in calcareous soils

    OpenAIRE

    Memon, Mehruinsa

    2008-01-01

    Agronomic efficiency and management of environmental P inputs can be improved by understanding soil-phosphorus interaction. Iron oxides and other clay minerals, P forms, and P sorption in young alluvial and weathered residual soils were determined. Phosphorus retention related to crystallinity and phase distribution of iron oxides. CBD and oxalate extractable iron and aluminum and smectite and kaolinite explained 90% variation while soil CaCO3 role was only insignificant in explaining P sorpt...

  6. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    OpenAIRE

    D. Kocman; Horvat, M.

    2010-01-01

    Results obtained by a laboratory flux measurement system (LFMS) focused on investigating the kinetics of the mercury emission flux (MEF) from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1) and land cover (forest, meadow and alluvial soil) alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, ...

  7. Alluvial fan dynamics in the El'gygytgyn Crater: implications for the 3.6 Ma old sediment archive

    Directory of Open Access Journals (Sweden)

    G. Schwamborn

    2012-06-01

    Full Text Available A sedimentological program has been conducted using frozen core samples from the 141.5 m long El'gygytgyn 5011-3 permafrost well. The drill site is located in sedimentary permafrost west of the lake that partly fills the El'gygytgyn Crater. The total core sequence is interpreted as strata building up a progradational alluvial fan delta. Four structurally and texturally distinct sedimentary units are identified. Unit 1 (141.5–117.0 m is comprised of ice-cemented, matrix-supported sandy gravel and intercalated sandy layers. Sandy layers represent sediments which rained out as particles in the deeper part of the water column under highly energetic conditions. Unit 2 (117.0–24.25 m is dominated by ice-cemented, matrix-supported sandy gravel with individual gravel layers. Most of the unit 2 diamicton is understood to result from alluvial wash and subsequent gravitational sliding of coarse-grained material on the basin slope. Unit 3 (24.25–8.5 m has ice-cemented, matrix-supported sandy gravel that is interrupted by sand beds. These sandy beds are associated with flooding events and represent near-shore sandy shoals. Unit 4 (8.5–0.0 m is ice-cemented, matrix-supported sandy gravel with varying ice content, mostly higher than below. It consists of slope material and creek fill deposits. The uppermost meter is the active layer into which modern soil organic matter has been incorporated. The nature of the progradational sediment transport taking place from the western and northern crater margins may be related to the complementary occurrence of frequent turbiditic layers in the central lake basin as is known from the lake sediment record. Slope processes such as gravitational sliding and sheet flooding that takes place especially during spring melt are thought to promote mass wasting into the basin. Tectonics are inferred to have initiated the fan accumulation in the first place and possibly the off-centre displacement of the crater lake.

  8. Simulation of Carbon-14 Migration Through a Thick Unsaturated Alluvial Basin Resulting from an Underground Nuclear Explosion

    Science.gov (United States)

    Martian, P.; Larentzos, J.

    2008-12-01

    Yucca Flat is one of several areas on the Nevada Test Site that was used for underground nuclear testing. Extensive testing performed in the unsaturated and saturated zones have resulted in groundwater contamination and surface subsidence craters in the vicinity of the underground test areas. Simulation of multiphase 14C transport through the thick Yucca Flat alluvial basin was performed to estimate the magnitude of radionuclide attenuation occurring within the unsaturated zone. Parameterization of the 14C transport in the multiphase flow and transport simulator (FEHM) was verified with experimental data collected from a large unsaturated soil column experiment. The experimental data included 14C as a radio-labeled bicarbonate solution, SF6 gas, and lithium bromide solution breakthroughs. Two representative simulation cases with working points located at shallow and deep depths relative to the water table were created to investigate the impact of subsidence crater-enhanced recharge, crater-playa areal extent, gas-phase partitioning, solid-phase partitioning, and a reduced permeability/porosity compressed zone created during the explosion on 14C transport. The representative shallow test had a detonation point located 175 m below land surface, and the deep test had a working point 435 m below land surface in a 500 m deep unsaturated zone. Carbon-14 transport is influenced by gas-phase diffusion and sorption within the alluvium. Gas-phase diffusion is an attenuation mechanism that transports 14C gas as 14CO2 throughout the unsaturated zone and exposes it to a large amount of soil moisture, resulting in dilute concentrations. The simulations indicated that the majority of the 14C inventory remains in the unsaturated zone over a 1,000-year time period after detonation because gas-phase diffusion moves the bulk of the 14C away from the higher recharge occurring in crater playas. Retardation also plays a role in slowing advective aqueous phase transport to the water

  9. Effect of Oxalic Acid on Potassium Release from Typical Chinese Soils and Minerals

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Xin; GUO Zhi-Fen; SUN Jin-He

    2007-01-01

    Oxalic acid plays an important role in improving the bioavailability of soil nutrients. Batch experiments were employed to examine the influences of oxalic acid on extraction and release kinetics of potassium (K) from soils and minerals along with the adsorption and desorption of soil K+. The soils and minerals used were three typical Chinese soils, black soil (Mollisol), red soil (Ultisol), and calcareous alluvial soil (Entisol), and four K-bearing minerals, biotite, phlogopite, muscovite, and microcline. The results showed that soil K extracted using 0.2 mol L-1 oxalic acid was similar to that using 1 mol L-1 boiling HNO3. The relation between K release (y) and concentrations of oxalic acid (c) could be best described logarithmically as y=a+blogc, while the best-fit kinetic equation of K release was y=a +b√t, where a and b are the constants and t is the elapsed time. The K release for minerals was ranked as biotite> phlogopite>> muscovite> microcline and for soils it was in the order: black soil> calcareous alluvial soil> red soil. An oxalic acid solution with low pH was able to release more K from weathered minerals and alkaline soils. Oxalic acid decreased the soil K+ adsorption and increased the soil K+ desorption, the effect of which tended to be greater at lower solution pH, especially in the red soil.

  10. Patterns and Processes of Width Adjustment to Increased Streamflows in Semi-Alluvial Rivers

    Science.gov (United States)

    Kelly, S. A.; Belmont, P.

    2015-12-01

    While it is understood that river channel width is determined by fluxes of water and sediment, predictive models of channel width, and especially changes in width under non-stationary conditions, have proven elusive. Classic hydraulic geometry relations commonly used in numerical models and channel design typically scale width as a power law function of discharge, without consideration of bank properties. This study investigates the role of bank material in determining spatial and temporal variability in channel width and widening rates for semi-alluvial rivers that have experienced increases in flow. The 45,000 km2 Minnesota River Basin contains many semi-alluvial rivers that have been rapidly incising into fine-grained glacial deposits over the last 13,400 years in response to a catastrophic base level drop. Large, recent increases in streamflows have caused significant channel widening and migration, exacerbated erosion of channel (alluvial) banks and (consolidated till) bluffs, and dramatically increased sediment supply. Here we leverage multiple decades of aerial photos, repeat lidar surveys, Structure from Motion photogrammetry and sediment gaging to examine past, and predict future, changes in channel width. We use empirical observations and a simple model to examine whether semi-alluvial channels tend toward a single, or multiple, equilibrium channel width(s). Preliminary results suggest that under stationary hydrologic conditions (1930s - 1970s) channel width was relatively consistent among reaches underlain by alluvium versus consolidated till. Since the late 1970s the study area has undergone profound hydrologic changes, with geomorphically-active flows nearly doubling in magnitude. Alluvial reaches widened relatively quickly in response to the increase in flows, whereas reaches underlain by till have not seen the same amount of widening. Aerial lidar-based geomorphic change detection between 2005 - 2012 records channel width changes in response to an

  11. The organic and mineral matter contents in deposits infilling floodplain basins: Holocene alluviation record from the Kłodnica and Osobłoga river valleys, southern Poland

    Science.gov (United States)

    Wójcicki, K. J.; Marynowski, L.

    2012-07-01

    The work examines the timing and environmental conditions of floodplain sedimentation in the valleys of the upland Kłodnica and piedmont Osobłoga rivers in the Upper Odra River basin. A distribution of 52 14C-ages shows relatively high floodplain sedimentation at the Late Glacial-Holocene transition, more stable floodplain environments since the Early (in the Kłodnica Valley) and Middle Holocene (in the Osobłoga Valley) and a gradual increase in floodplain deposition in the Late Holocene (since hydrological events) as well as factors affecting the local record of sedimentation (i.e. valley morphology, hydrologic conditions and episodes of local erosion). A clear relationship is shown between an increase in alluviation and climate- or human-induced extension of unforested areas. The deposition of mineral-rich sediments increases rapidly during periods characterized by non-arboreal pollen values exceeding approximately 8% in pollen diagrams. On the other hand, the results obtained do not confirm significant interactions between Holocene changes in forest composition and alluviation. Despite the settlement of agrarian groups, the sedimentary record of human activity in the Osobłoga catchment is very poor during the Neolithic and early Bronze Age. A large-scale alluviation of the Osobłoga and Kłodnica valleys was initiated during the settlement of people of the Lusatian culture from the middle Bronze Age and escalated in the early Middle Ages and Modern Times. The deposition of products of soil erosion was limited to between ca. 1.9-1.2 kyr BP, probably due to demographic regression during the Migration Period. Comparison of OM/MM fluctuations with phases of increased fluvial activity does not show a relationship between Holocene wetter phases and catchment sediment yield. Sedimentary episodes in the Upper Odra basin also show a low degree of correlation with the probability density curve of the 14C-ages. The results obtained in the Kłodnica and Osob

  12. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and...

  13. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses...

  14. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The...

  15. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant recharge values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace...

  16. The Importance of Lower Mississippi River Alluvial Valley Reforestation and Wetland Restoration Sites to Wintering Migratory Birds; Annual Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Major efforts have been initiated in the Lower Mississippi River Alluvial Valley (LMA V. Fig. I) from within both the U.S. Departments of Interior and Agriculture...

  17. Seismic Site Effects for Shallow and Deep Alluvial Basins: In-Depth Motion and Focusing Effect

    CERN Document Server

    Semblat, Jean-François; Kham, Marc; Duval, Anne Marie

    2009-01-01

    The main purpose of the paper is the analysis of seismic site effects in various alluvial basins. The analysis is performed considering a numerical approach (Boundary Element Method). Two main cases are considered : a shallow deposit in the centre of Nice (France) [1] and a deep irregular basin in Caracas (Venezuela) [2]. The amplification of seismic motion is analysed in terms of level, occuring frequency and location. For both sites, the amplification factor is found to reach maximum values of 20 (weak motion). Site effects nevertheless have very different features concerning the frequency dependence and the location of maximum amplification. For the shallow deposit in Nice, the amplification factor is very small for low frequencies and fastly increases above 1.0 Hz. The irregular Caracas basin gives a much different frequency dependence with many different peaks at various frequencies. The model for Caracas deep alluvial basin also includes a part of the local topography such as the nearest mountain. One c...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-28

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

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

    Science.gov (United States)

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

    2011-12-01

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

  20. Determination of vulnerability areas to pollution: case of alluvial water table of Tebessa (East Algeria)

    International Nuclear Information System (INIS)

    This work related to the alluvial water table of Tebessa, which is characterised by a semi-dry climate and a very heterogeneous geology. To examine the pollution problem who seems exists, we have used two methods: the DRASTICS method who combines the information given by the seven parameters leading to the map of vulnerability to pollution and a second method that is based on hydrochemistry and take into account the results of the ratio Sr2/Ca2+. (Author)

  1. Hydrological and chemical budgets of a mire pool formed on alluvial lowland of Hokkaido, northern Japan

    OpenAIRE

    Kizuka, Toshikazu; Yamada, Hiroyuki; Hirano, Takashi

    2011-01-01

    Mire pools - permanently water-filled depressions on peatlands - provide important habitats for myriad organisms. Recently, water balance change and eutrophication resulting from agricultural development are increasingly evident in mire pools of alluvial lowlands. Conservation of mire pool hydrochemistry is necessary. We investigated the hydrological and chemical budgets of a pristine mire pool, Akanuma Pool (95,280 m2 area; 1.8 m mean depth), located in Kushiro Mire in Hokkaido, northern Jap...

  2. Assessing Effects of Climate Change on Biogeochemical Cycling of Trace Metals in Alluvial and Coastal Watersheds

    OpenAIRE

    Lee, Ming-Kuo; Natter, Michael; Keevan, Jeff; Guerra, Kirsten; Saunders, James; Uddin, Ashraf; Humayun, Munir; Wang, Yang; Keimowitz, Alison R.

    2013-01-01

    Assessing the impacts of climate changes on water quality requires an understanding of the biogeochemical cycling of trace metals. Evidence from research on alluvial aquifers and coastal watersheds shows direct impacts of climate change on the fate and transformation of trace metals in natural environments. The case studies presented here use field data and numerical modeling techniques to test assumptions about the effects of climate change on natural arsenic contamination of groundwater in ...

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

    OpenAIRE

    Majkić-Dursun Brankica; Vulić Predrag; Dimkić Milan

    2015-01-01

    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 geochemic...

  4. Developing a coupled analytical model for analyzing salt intrusion in alluvial estuaries

    Science.gov (United States)

    Savenije, H.; CAI, H.; Gisen, J.

    2013-12-01

    A predictive assessment technique to estimate the salt intrusion length and longitudinal salinity distribution in estuaries is important for policy makers and managers to maintain a healthy estuarine environment. In this study, the salt intrusion model of Savenije (2005, 2012) is applied and coupled to an explicit solution for tidal dynamics developed by Cai and Savenije (2013). The objective of the coupling is to reduce the number of calibration parameters, which subsequently strengthens the reliability of the salt intrusion model. Moreover, the fully analytical treatment allows assessing the effect of model forcing (i.e., tide and river discharge) and geometry adjustments (e.g., by dredging) on system performance. The coupled model has been applied to a wide range of estuaries, and the result shows that the correspondence between analytical estimations and observations is very good. As a result, the coupled model is a useful tool for decision makers to obtain first order estimates of salt intrusion in estuaries based on a minimum of information required. References Savenije, H.H.G. (2005), Salinity and Tides in Alluvial Estuaries, Elsevier. Savenije, H.H.G. (2012), Salinity and Tides in Alluvial Estuaries, completely revised 2nd edition, www.salinityandtides.com. Cai, H., and H. H. G. Savenije (2013), Asymptotic behavior of tidal damping in alluvial estuaries, Journal of Geophysical Research, submitted.

  5. Identification of a late Quaternary alluvial-aeolian sedimentary sequence in the Sichuan Basin, China

    Science.gov (United States)

    Feng, Jin-Liang; Ju, Jian-Ting; Chen, Feng; Hu, Zhao-Guo; Zhao, Xiang; Gao, Shao-Peng

    2016-03-01

    The late Quaternary sedimentary sequence in the northwestern part of the Sichuan Basin consists of five lithological units and with increasing depth include the: Chengdu Clay; Brown Clay; Red Clay; Sandy Silt; and basal Muddy Gravel. The genesis, provenance and age of the sediments, as well as the possible presence of hiatuses within this sequence are debated. Measurements of grain-size, magnetic susceptibility, quartz content, quartz δ18O values, element composition, and Sr-Nd isotopic concentrations of samples from a typical sedimentary sequence in the area provides new insights into the genesis and history of the sequence. The new data confirm that the sediments in study site are alluvial-aeolian in origin, with basal alluvial deposits overlain by aeolian deposits. Like the uppermost Chengdu Clay, the underlying Brown Clay and Red Clay are aeolian in origin. In contrast, the Silty Sand, like the basal Muddy Gravel, is an alluvial deposit and not an aeolian deposit as previously thought. Moreover, the succession of the aeolian deposits very likely contains two significant sedimentary hiatuses. Sedimentological analysis demonstrates that the source materials for the aeolian deposits in the northwestern part of the Sichuan Basin and those on the eastern Tibetan Plateau are different. Furthermore, the loess deposits on the eastern Tibetan Plateau are derived from heterogeneous local sources.

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

    Directory of Open Access Journals (Sweden)

    LEANDRO VALLE FERREIRA

    2013-09-01

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

  7. Floodplain morphology, sedimentology, and development processes of a partially alluvial channel

    Science.gov (United States)

    Thayer, James B.; Ashmore, Peter

    2016-09-01

    The floodplain morphology, sediment deposits, and development mechanisms of a partially alluvial, low-moderate energy channel flowing over a mixed gravel/cobble-till bed are investigated and compared to existing ideas of floodplain development. The findings partially support the idea of a floodplain developed through lateral accretion capped with vertically accreted sediments as predicted by the energy-based classification scheme of Nanson and Croke (1992), though oblique accretion and partial channel avulsion are also important. Channel migration consists of limited cross-valley migration and downstream meander translation. Because of low channel sinuosity, well-formed neck cutoffs are rare, and instead the channel cuts headward along the insides of confined or underdeveloped meander bends forming a localized anabranching pattern. The floodplain architecture can be divided into gravel bar and bed deposits (GB), lateral accretion deposits (LA), overbank deposits (FF), and abandoned channel deposits (FF(CH)), which are described with four alluvial facies. Owing to the limited supply of coarse and fine sediment, none of the architectural elements are particularly thick, with total floodplain thickness being channels is compared within a new floodplain discrimination framework. Comparisons with common facies models of single-thread, coarse-grained channels show important differences that suggest that the floodplain deposits and formative processes described herein represent a subset of single-thread systems that may be common in partially alluvial channels, particularly in slightly sinuous, coarse-grained channels of low-moderate energy with partly confined floodplains.

  8. Self-similar growth of an alluvial fan fed with bimodal sediment

    Science.gov (United States)

    Delorme, Pauline; Voller, Vaughan; Paola, Chris; Devauchelle, Olivier; Lajeunesse, Eric; Barrier, Laurie; Métivier, François

    2016-04-01

    At the outlet of mountain ranges, rivers flow onto flatter lowlands. The associated change of slope causes sediment deposition. As the river is free to move laterally, it builds conical sedimentary structures called alluvial fans. Their location at the interface between erosional and depositional areas makes them valuable sedimentary archives. To decipher these sedimentary records, we need to understand the dynamics of their growth. We carried out a series of experiments to investigate the growth of alluvial fans fed with mixed sediments. The density difference between silica and coal sediments mimics a bimodal grain-size distribution in nature. The sediment and water discharges are constant during an experiment. During the run, we track the evolution of the surface pattern by digital imaging. At the end of each run, we acquire the fan topography using a scanning laser. Finally, we cut a radial cross section to visualize the sedimentary deposit. We observe there is a distinct slope break at the transition that dominates the overall curvature of the fan surface. Based on mass conservation and observations, we propose that this alluvial fan grows in a self-similar way, thus causing the transition between silica and coal deposits to be a straight line. The shape of the experimental transition accords with this prediction.

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

    Science.gov (United States)

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

    2001-01-01

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

  10. Rapid delineation of alluvial fans using IfSAR-derived DEM for selected provinces in the Philippines

    Science.gov (United States)

    Ortiz, Iris Jill; Aquino, Dakila; Norini, Gianluca; Narod Eco, Rodrigo; Mahar Lagmay, Alfredo

    2015-04-01

    Alluvial fans are fan-shaped geomorphic features formed when sediments from a watershed are transported and deposited downstream via tributaries flowing out from the sudden break of a slope. Hazards usually associated with alluvial fans are flooding and debris flows. In this study, we used an Interferometric Synthetic Aperture Radar-derived digital elevation model of Pangasinan and Nueva Ecija Provinces in the Philippines to identify and delineate alluvial fans. Primary parameters considered include the geomorphic characteristics of the catchment area, stream network and slopes ranging from 0.11 to 8 degrees. Using this method, 12 alluvial fans were identified in Pangasinan and 16 in Nueva Ecija with areas ranging from 0.35 to 80 sq. km. The largest fan identified is the Mangatarem-Aguilar fan in Pangaisnan with a total area of 80.87 sq km while the Gabaldon fan in Nueva Ecija with total area of 48.11 sq km. We observed from the results that some alluvial fans have multiple feeder streams, and others have overlapping lateral extents with adjacent fans. These overlapping fans are called bajadas. In addition, the general location of fans and their apices in the two provinces appear to coincide with segments of the Philippines Fault System. There are about people 1.4 million living within these alluvial fans. Mapping and characterizing and identifying their associated hazards is crucial in the disaster preparedness efforts of the exposed population.

  11. Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica.

    NARCIS (Netherlands)

    Nieuwenhuyse, A.

    1996-01-01

    The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern side it is b

  12. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    Science.gov (United States)

    Kocman, D.; Horvat, M.

    2010-02-01

    Results obtained by a laboratory flux measurement system (LFMS) focused on investigating the kinetics of the mercury emission flux (MEF) from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4-417 μg g-1) and land cover (forest, meadow and alluvial soil) alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m-2 h-1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.

  13. Hydrogeophysics of gravel-dominated alluvial floodplains in eastern Oklahoma

    Science.gov (United States)

    Miller, Ronald B.

    Multi-electrode surface electrical resistivity (ERI) profiles of the floodplains show lenticular features with high resistivity within a domain of lower resistivity. Floodplain subsoil is composed of mixture of coarse and fine fractions (less than 0.25 mm). The proportion of the fine fraction from cores at the sites shows a negative power relationship with both resistivity (R2 = 0.85) and hydraulic conductivity (R 2 = 0.72), suggesting that the fine content is the major factor in the hydraulic and electrical behavior of the gravel subsoil. A linear relationship between hydraulic conductivity and resistivity is significant and the resulting equation Ksat = 0.11rho allows resistivity (rho) to be interpreted as saturated hydraulic conductivity (Ksat). The median hydraulic conductivity on all profiles from all sites was at least 20 m d-1, which is within the range for gravel soils. This high hydraulic conductivity suggests that at least half of the subsurface at each floodplain is likely to behave as a "high-flow domain" with the ability to conduct water at rates of 20 m d-1 or greater. Several ERI profiles at Barren Fork Creek (BFC) had high resistivity values that were significantly higher than the remaining ERI profiles at BFC and the other sites measured at the 84th percentile. Those ERI profiles were obtained from an area within the BFC study site where a trench injection test found a tracer (Rhodamine WT) to move in a manner that suggests preferential flow. A storm runoff pulse passed the BFC site over May 1-5, 2009 featuring 2.2 m of stage increase, which caused the water table to rise into the gravel-dominated vadose zone at the site. Water table maps, corresponding to the times when stream elevation matched the selected hydraulic conductivity elevations, were prepared from pressure transducers placed in monitoring wells at the site. It appeared that there was little attenuation of the energy of the storm pulse even at the furthest point in the study site: at

  14. Geomorphology, internal structure and evolution of alluvial fans at Motozintla, Chiapas, Mexico

    Science.gov (United States)

    Sánchez-Núñez, J. M.; Macías, J. L.; Saucedo, Ricardo; Zamorano, J. J.; Novelo, David; Mendoza, M. E.; Torres-Hernández, J. R.

    2015-02-01

    Alluvial fans and terraces develop in diverse regions responding to different tectonic and climatic conditions. The Motozintla basin is located in the State of Chiapas, southern Mexico and has an E-W orientation following the trace of the left-lateral Polochic Fault. The evolution of the Motozintla basin and the alluvial plain is related to several factors, such as fault movement, intense erosion by hydrometeorological events, and anthropogenic activity. This study presents the geomorphology of the alluvial plain that between the villages of Motozintla and Mazapa de Juárez exposes 31 alluvial fans, 5 hanging terraces and 13 ramps. Fourteen of these alluvial fans have been truncated by the Polochic fault, exposing maximum uplifts of ~ 12 m. The internal structure of truncated fans consists of single massive beds (monolithologic fans) or stacked beds (polygenetic fans). The fans' stratigraphy is made of debris flow deposits separated by paleosols and minor hyperconcentrated flows, fluviatile beds, and pyroclastic fall deposits. The reconstruction of the stratigraphy assisted by radiocarbon geochronology suggests that these fans have been active since late Pleistocene (25 ka) to the present. This record suggests that at least 10 events have been recorded at the fan interior during the past ~ 1840 years. One of these events at 355 ± 65 14C yrs. BP (cal yrs. AD 1438 to 1652) can be correlated across the fans and is likely associated with an extreme hydrometeorologic event. The presence of a 165 ± 60 14C yrs. BP (cal yrs. AD 1652-1949) debris flow deposit within the fans suggests that movement along the Polochic fault formed the fans' scarp afterwards. In fact, a historic earthquake along the fault occurred east of Motozintla on July 22, 1816 with a Mw of 7.5-7.75. Recent catastrophic floods have affected Motozintla in 1998 and 2005 induced by extreme hydrometeorological events and anthropogenic factors. Therefore, scenarios for Motozintla involved several types of

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

    Science.gov (United States)

    Williams, Martin

    2014-05-01

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

  16. Quantitative Assessment of Soil Health Under Different Planting Patterns and Soil Types

    Institute of Scientific and Technical Information of China (English)

    BI Chun-Juan; CHEN Zhen-Lou; WANG Jun; ZHOU Dong

    2013-01-01

    Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield,quality and human health.The objectives of this study were to select a minimum data set for soil health evaluation from the physical,chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai,China.The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition,accounting for 48.9% of the survey samples,followed by the medium healthy soil,accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island.The indicators of pH,total organic carbon,microbial biomass carbon and Cd exerted less influence on soil health,while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health.Dichlorodiphenyltrichloroethanes,hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field,greenhouse and open-air vegetable/watermelon fields.The difference of the SHI of the three soil types was significant at P=0.05.The paddy soil had the highest SHI values,followed by the gray alluvial soil,and the coastal saline soil was in a poor soil health condition,indicating a need to plant some salt-tolerant crops to effectively improve soil quality.

  17. Recharge source and hydrogeochemical evolution of shallow groundwater in a complex alluvial fan system, southwest of North China Plain

    Science.gov (United States)

    Li, Fadong; Pan, Guoying; Tang, Changyuan; Zhang, Qiuying; Yu, Jingjie

    2008-09-01

    Many cities around the world are developed at alluvial fans. With economic and industrial development and increase in population, quality and quantity of groundwater are often damaged by over-exploitation in these areas. In order to realistically assess these groundwater resources and their sustainability, it is vital to understand the recharge sources and hydrogeochemical evolution of groundwater in alluvial fans. In March 2006, groundwater and surface water were sampled for major element analysis and stable isotope (oxygen-18 and deuterium) compositions in Xinxiang, which is located at a complex alluvial fan system composed of a mountainous area, Taihang Mt. alluvial fan and Yellow River alluvial fan. In the Taihang mountainous area, the groundwater was recharged by precipitation and was characterized by Ca-HCO3 type water with depleted δ18O and δD (mean value of -8.8‰ δ18O). Along the flow path from the mountainous area to Taihang Mt. alluvial fan, the groundwater became geochemically complex (Ca-Na-Mg-HCO3-Cl-SO4 type), and heavier δ18O and δD were observed (around -8‰ δ18O). Before the surface water with mean δ18O of -8.7‰ recharged to groundwater, it underwent isotopic enrichment in Taihang Mt. alluvial fan. Chemical mixture and ion exchange are expected to be responsible for the chemical evolution of groundwater in Yellow River alluvial fan. Transferred water from the Yellow River is the main source of the groundwater in the Yellow River alluvial fan in the south of the study area, and stable isotopic compositions of the groundwater (mean value of -8.8‰ δ18O) were similar to those of transferred water (-8.9‰), increasing from the southern boundary of the study area to the distal end of the fan. The groundwater underwent chemical evolution from Ca-HCO3, Na-HCO3, to Na-SO4. A conceptual model, integrating stiff diagrams, is used to describe the spatial variation of recharge sources, chemical evolution, and groundwater flow paths in the

  18. Fixed Ammonium in Major Types of Paddy Soils in Hunan Province,China

    Institute of Scientific and Technical Information of China (English)

    ZHANG YANGZHU; LIAO JIPEI; SUN YUHUAN; FENG YUEHUA; HUANG YUNXIANG

    2003-01-01

    The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soilalluvial sandy paddy soil > purple clayey paddy soil > newly alluvial sandypaddy soil > yellow clayey paddy soil > reddish-yellow clayey paddy soil > granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with < 0.01 mm clay content(P < 0.05), but not with < 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type.

  19. Soil contamination; 1 : 500 000

    International Nuclear Information System (INIS)

    Inorganic soil contamination is expressed by the intersection of the sets of contents of risk elements exceeding the threshold values. It was compiled from the mono-element geochemical maps made by application of geostatistical methods based on the results of 5,189 chemical analyses of forest and agricultural soils. The density of soil sampling was 1 sample per 10 square kilometres in average. Point and diffuse soil contamination according to the limits in force (Decision of the Ministry of Agriculture of the Slovak Republic No. 531/1994-540) is represented on the map. The extent of the areas with relatively clean soils and the areas with higher background concentration of elements in soil is obvious. The spreading of the limit exceeding contents of risk elements is related to the geochemical, but above all anthropogenically produced, contamination sources in the areas of old mining, processing and metallurgical factories (Central Slovakia and the Spis-Gemer area). It also indicates the transfer of contaminants into the alluvial zones of rivers and brooks. (authors)

  20. Soil Formation and Taxonomy in Yeşilırmak River Terraces

    Directory of Open Access Journals (Sweden)

    Alper Durak

    2014-02-01

    Full Text Available In this study, the soils of which parent material is alluvial and formed Yeşilırmak river terraces were investigated. For this purposes four different profiles were excavated in the study area. Then twenty-seven soil samples were taken from horizons of four profiles and their physical and chemical analyses were done for soil taxonomy research. Profile of Kumocagi and Cakil were classified in subgroup as Typic Ustipsamments, Havaalanı and Mera profiles were classified Typic Haplustolls and Typic Argiustolls subgroups respectively. The pH values of soils varied between 7.38-8.41. These soils can be classified as low and highly basic. Most of the soil series had an irregular pH distribution in the profile. The range of carbonate content of the soils was 0.8-25.4%. Although carbonate content of soils showed a very wide range, majority of them can be classified as highly calcareous. In most of soils carbonate content was distributed irregulary in the profile. Organic matter content were between 0.14-6.11% in the soils. Although organic matter contents of the soils changed in a wide range most of them had low organic matter content. Organic matter content was over 4% in the surface horizon of only two profiles. Research result showed that, alluvial parent material, particle size, topograpy and time have different effect on investigation soils.

  1. Review of soil moisture flux studies at the Nevada Test Site, Nye County, Nevada

    International Nuclear Information System (INIS)

    This report documents almost 30 years of research on soil moisture movement and recharge at the Department of Energy, Nevada Test Site. Although data is scarce, three distinct topographic zones are represented: alluvial valleys, inundated terrains, and upland terrain. Recharge in alluvial valleys was found to be very small or negligible. Ponded areas such as playas and subsidence craters showed significant amounts of recharge. Data in the upland terrains is very scarce but one area, Rainier Mesa, shows active recharge of up to three percent of the annual average precipitation in fractured volcanic tuff. The report summarizes the results

  2. Bioindication in Urban Soils in Switzerland

    Science.gov (United States)

    Amossé, J.; Le Bayon, C.; Mitchell, E. A. D.; Gobat, J. M.

    2012-04-01

    functionality of urban soils and alluvial soils, used as a natural reference because of their regular physical perturbation by flooding and associated erosion/sedimentation, (iv) evaluation of soil bioindicators (e.g. earthworm, enchytraeid and testate amoebae) for urban soils. The application objective of my research is to introduce bioindicators and their limit values for the future revision of the legal Ordonnance on soils (OSol), and to develop guidelines to improve or to build urban soils with the aim of reaching a sustainable urban ecosystem development.

  3. Analysis of Soil Heavy Metal Pollution and Pattern in Central Transylvania

    OpenAIRE

    Lorentz Jäntschi; Sorana D. Bolboacă; Mihai Todică; Constantin Cosma; Ioan Suciu

    2008-01-01

    The concentration of five soil heavy metals (Pb, Co, Cr, Cu, Hg) was measured in forty sampling sites in central Transylvania, Romania, regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using the Inductively Coupled Plasma Spectrometry method. Data were verified by using the Neu...

  4. Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production

    Science.gov (United States)

    Lockhart, K. M.; King, A. M.; Harter, T.

    2013-08-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤ 150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10 mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤ 21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated

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

    Science.gov (United States)

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

    2014-11-15

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

  6. Regional water quality patterns in an alluvial aquifer: direct and indirect influences of rivers.

    Science.gov (United States)

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

    2014-11-15

    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.

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

    Science.gov (United States)

    Sweetkind, Donald S.; Drake II, Ronald M.

    2007-01-01

    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.

  8. Geotechnical Investigations on Sediments from Alluvial Fans in the Upper Sava River Valley, NW Slovenia

    Science.gov (United States)

    Petkovšek, A.; Maček, M.; Mikoš, M.

    2009-04-01

    In order to estimate whether any alluvial (torrential) fan should be rather classified as a debris cone (mainly formed by debris flows; at least occasionally threatened by debris flows) we performed a combined field and laboratory investigation on selected alluvial fans in the Upper Sava River valley between Rateče (border to Italy) and Jesenice in NW Slovenia. This work was done as a part of three year targeted research project "Debris flow risk assessment in Slovenia". This region was chosen due to its high potential for debris flow generation. In the distal or/and in the proximal part of each of the selected alluvial fans (Trebiža, Suhelj, Presušnik, Koroška Bela, Javorniški Rovt), one or two sedimentological trenches reaching over 5 m in depth were excavated. For each trench we assured qualitative geological (sedimentological) inventory and description of lithological structure, and in some trenches we tried to assess age of the sediments. From selected layers in different depths in the majority of trenches sediment samples have been taken for further geotechnical laboratory investigations. The main aim of the study was to assess transport properties of sediment material to flow in the form of a debris flow. We compared elaborated values of the main geotechnical parameters (grain size distribution, USCS classification, natural water content, Atterberg limits, plasticity index, density, dry density, shear strength as a function of sample water content) of these sediment samples with known corresponding values for samples taken in the past from other active landslides (Macesnik, Slano Blato) and debris flows (Stože, Strug) in Slovenia. The comparison of the samples' shear strengths as a function of sample water content has shown that samples from selected alluvial fans don't contain enough fines and are less sensitive to water content as the samples taken from the Stože debris flow, that was in November 2000 with the magnitude of over 1 million m3 the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-01

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

  10. Conceptual model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

    Heilweil, Victor M.; Brooks, Lynette E.

    2011-01-01

    A conceptual model of the Great Basin carbonate and alluvial aquifer system (GBCAAS) was developed by the U.S. Geological Survey (USGS) for a regional assessment of groundwater availability as part of a national water census. The study area is an expansion of a previous USGS Regional Aquifer Systems Analysis (RASA) study conducted during the 1980s and 1990s of the carbonate-rock province of the Great Basin. The geographic extent of the study area is 110,000 mi2, predominantly in eastern Nevada and western Utah, and includes 165 hydrographic areas (HAs) and 17 regional groundwater flow systems.

  11. [Sanitary evaluation of microclimate conditions at the ore mining and alluvial pits sites].

    Science.gov (United States)

    Chebotarev, A G; Afanas'eva, R F

    1998-01-01

    The authors summarized results of hygienic research carried in pits of Transbaikal region, Yakutia. Tchukotka, Kazakhstan, Kirgizia, Krivoy Rog, European North and other areas. Microclimate parameters in winze of mining and alluvial pits appeared to vary significantly and to depend on certain specific factors (depth of mining, climate geographic zone of the enterprise, temperature of the ores treated, etc.). Considering degree of influence on workers' heat state, taking into account significance of clothes heat insulation required, the authors defined 4 types of microclimate at workplace. For operative selection of optimal special clothing set, the authors represent dependence of proper heat resistance of clothes for main and auxiliary occupations on microclimate conditions. PMID:9855739

  12. Modeling flow and sediment transport dynamics in the lowermost Mississippi River, Louisiana, USA, with an upstream alluvial-bedrock transition and a downstream bedrock-alluvial transition: Implications for land building using engineered diversions

    Science.gov (United States)

    Viparelli, Enrica; Nittrouer, Jeffrey A.; Parker, Gary

    2015-03-01

    The lowermost Mississippi River, defined herein as the river segment downstream of the Old River Control Structure and hydrodynamically influenced by the Gulf of Mexico, extends for approximately 500 km. This segment includes a bedrock (or more precisely, mixed bedrock-alluvial) reach that is bounded by an upstream alluvial-bedrock transition and a downstream bedrock-alluvial transition. Here we present a one-dimensional mathematical formulation for the long-term evolution of lowland rivers that is able to reproduce the morphodynamics of both the alluvial-bedrock and the bedrock-alluvial transitions. Model results show that the magnitude of the alluvial equilibrium bed slope relative to the bedrock surface slope and the depth of bedrock surface relative to the water surface base level strongly influence the mobile bed equilibrium of low-sloping river channels. Using data from the lowermost Mississippi River, the model is zeroed and validated at field scale by comparing the numerical results with field measurements. The model is then applied to predict the influence on the stability of channel bed elevation in response to delta restoration projects. In particular, the response of the river bed to the implementation of two examples of land-building diversions to extract water and sediment from the main channel is studied. In this regard, our model results show that engineered land-building diversions along the lowermost Mississippi River are capable of producing equilibrated bed profiles with only modest shoaling or erosion, and therefore, such diversions are a sustainable strategy for mitigating land loss within the Mississippi River Delta.

  13. Research of vertical migration of radionuclides in the soil at testing 'Red forest' area

    International Nuclear Information System (INIS)

    Researches of vertical migration of Chernobyl origin radionuclides at testing 'Red forest' rea in 5-km ChNPP-zone were carried out. The γ- and β- spectrometer measurements of soil samples were carried out using the anticompton spectrometer and a beta spectrometer. Presence of 60Co, 134, 137Cs, 154,155Eu, 241Am to depth of 30 cm in all soil cuts was fixed. The sites with sod-low-podzol sandy soils on alluvial sands contain 137Cs, 90Sr and 241Am to depth of 60 cm. The presence 243Am and 243Cm was found in the top layers of soils at territory of testing area.

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

    International Nuclear Information System (INIS)

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

  15. Rates of soil development from four soil chronosequences in the southern Great Basin

    Science.gov (United States)

    Harden, J.W.; Taylor, E.M.; Hill, C.; Mark, R.K.; McFadden, L.D.; Reheis, M.C.; Sowers, J.M.; Wells, S.G.

    1991-01-01

    Four soil chronosequences in the southern Great Basin were examined in order to study and quantify soil development during the Quaternary. Soils of all four areas are developed in gravelly alluvial fans in semiarid climates with 8 to 40 cm mean annual precipitation. Lithologies of alluvium are granite-gneiss at Silver Lake, granite and basalt at Cima Volcanic Field, limestone at Kyle Canyon, and siliceous volcanic rocks at Fortymile Wash. Ages of the soils are approximated from several radiometric and experimental techniques, and rates are assessed using a conservative mathematical approach. Average rates for Holocene soils at Silver Lake are about 10 times higher than for Pleistocene soils at Kyle Canyon and Fortymile Wash, based on limited age control. Holocene soils in all four areas appear to develop at similar rates, and Pleistocene soils at Kyle Canyon and Fortymile Wash may differ by only a factor of 2 to 4. Over time spans of several millennia, a preferred model for the age curves is not linear but may be exponential or parabolic, in which rates decrease with increasing age. These preliminary results imply that the geographical variation in rates within the southern Great Basin-Mojave region may be much less significant than temporal variation in rates of soil development. The reasons for temporal variation in rates and processes of soil development are complexly linked to climatic change and related changes in water and dust, erosional history, and internally driven chemical and physical processes. ?? 1991.

  16. Quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding

    Science.gov (United States)

    Parsons, D. R.; Simmons, S.; Best, J.

    2010-12-01

    Multibeam Echo-Sounder systems have developed rapidly over recent decades and are routinely deployed to provide high-resolution bathymetric details in range of aquatic environments. Modern data handling and storage technologies now facilitate the logging of the raw acoustic back-scatter information that was previously discarded by these systems. This paper describes methodologies that exploit this logging capability to quantify the concentration and dynamics of suspended sediment within the water column and presents a novel method that also allows for quantification of 2D flow velocities. This development provides a multi-purpose tool for the holistic surveying of the process linkages between flow, sediment transport and bed morphology. The application of this new technique is illustrated with reference to flow over alluvial sand dunes, which allows, for the first time in a field study, quantitative visualization of larg-scale, whole flow field, turbulent coherent flow structures, associated with the dune leeside, that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows. CFS captured by MBES in the lee of an alluvial dune. Contours of suspended sediment concentration and superimposed 2D flow velocity vectors

  17. Geomorphology-based index for detecting minimal flood stages in arid alluvial streams

    Directory of Open Access Journals (Sweden)

    E. Shamir

    2012-11-01

    Full Text Available Identification of a geomorphic index to represent lower thresholds for minor flows in ephemeral, alluvial streams in arid environments is an essential step in reliable flash flood hazard estimations and establishing flood warning systems. An index, termed Alluvial wadi Flood Incipient Geomorphologic Index (AFIG, is presented. Analysis of data from an extensive field survey in the arid ephemeral streams in Southern and Eastern Israel was conducted to investigate the AFIG and the control over its value across the region. During the survey we identified distinguishable flow marks in the lower parts of streams' banks, such as niches, vegetation line, and change in bank material, which are indicative of low flows. The cross-sectional characteristics of the AFIG were studied in relationship with contributing drainage basin characteristics such as lithology, topography, and precipitation. Drainage area and hardness of the exposed lithology (presented as a basin-wide index are the preferred descriptors to be used in estimating a specific AFIG in un-surveyed sites. Analyses of discharge records from seven hydrometric stations indicate that the recurrence interval of the determined AFIG is equal to or more frequent than 0.5 yr.

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

    Science.gov (United States)

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

    2013-01-01

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

  19. Geomorphology-based index for detecting minimal flood stages in arid alluvial streams

    Science.gov (United States)

    Shamir, E.; Ben-Moshe, L.; Ronen, A.; Grodek, T.; Enzel, Y.; Georgakakos, K. P.; Morin, E.

    2013-03-01

    Identification of a geomorphic index to represent lower thresholds for minor flows in ephemeral, alluvial streams in arid environments is an essential step as a precursor for reliable flash flood hazard estimations and establishing flood warning systems. An index, termed Alluvial wadi Flood Incipient Geomorphologic Index (AFIG), is presented. Analysis of data from an extensive field survey in the arid ephemeral streams in southern and eastern Israel was conducted to investigate the AFIG and the control over its value across the region. During the survey we identified distinguishable flow marks in the lower parts of streams' banks, such as niches, vegetation line, and change in bank material, which are indicative of low flows. The cross-sectional characteristics of the AFIG were studied in relationship with contributing drainage basin characteristics such as lithology, topography, and precipitation. Drainage area and hardness of the exposed lithology (presented as a basin-wide index) are the preferred descriptors to be used in estimating a specific AFIG in unsurveyed sites. Analyses of discharge records from seven hydrometric stations indicate that the recurrence interval of the determined AFIG is equal to or more frequent than 0.5 yr.

  20. Object-based forest classification to facilitate landscape-scale conservation in the Mississippi Alluvial Valley

    Science.gov (United States)

    Mitchell, Michael; Wilson, R. Randy; Twedt, Daniel J.; Mini, Anne E.; James, J. Dale

    2016-01-01

    The Mississippi Alluvial Valley is a floodplain along the southern extent of the Mississippi River extending from southern Missouri to the Gulf of Mexico. This area once encompassed nearly 10 million ha of floodplain forests, most of which has been converted to agriculture over the past two centuries. Conservation programs in this region revolve around protection of existing forest and reforestation of converted lands. Therefore, an accurate and up to date classification of forest cover is essential for conservation planning, including efforts that prioritize areas for conservation activities. We used object-based image analysis with Random Forest classification to quickly and accurately classify forest cover. We used Landsat band, band ratio, and band index statistics to identify and define similar objects as our training sets instead of selecting individual training points. This provided a single rule-set that was used to classify each of the 11 Landsat 5 Thematic Mapper scenes that encompassed the Mississippi Alluvial Valley. We classified 3,307,910±85,344 ha (32% of this region) as forest. Our overall classification accuracy was 96.9% with Kappa statistic of 0.96. Because this method of forest classification is rapid and accurate, assessment of forest cover can be regularly updated and progress toward forest habitat goals identified in conservation plans can be periodically evaluated.

  1. Well-balanced numerical modelling of non-uniform sediment transport in alluvial rivers

    Institute of Scientific and Technical Information of China (English)

    Honglu Qian; Zhixian Cao; Gareth Pender; Huaihan Liu; Peng Hu

    2015-01-01

    abstract The last two decades have witnessed the development and application of well-balanced numerical models for shallow flows in natural rivers. However, until now there have been no such models for flows with non-uniform sediment transport. This paper presents a 1D well-balanced model to simulate flows and non-capacity transport of non-uniform sediment in alluvial rivers. The active layer formulation is adopted to resolve the change of bed sediment composition. In the framework of the finite volume Slope LImiter Centred (SLIC) scheme, a surface gradient method is incorporated to attain well-balanced solutions to the governing equations. The proposed model is tested against typical cases with irregular topography, including the refilling of dredged trenches, aggradation due to sediment overloading and flood flow due to landslide dam failure. The agreement between the computed results and measured data is encouraging. Compared to a non-well-balanced model, the well-balanced model features improved performance in reproducing stage, velocity and bed deformation. It should find general applications for non-uniform sediment transport modelling in alluvial rivers, especially in mountain areas where the bed topography is mostly irregular.

  2. Correlation and dating of Quaternary alluvial-fan surfaces using scarp diffusion

    Science.gov (United States)

    Hsu, Leslie; Pelletier, Jon D.

    2004-06-01

    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.

  3. Effect of heterogeneity on radionuclide retardation in the alluvial aquifer near Yucca Mountain, Nevada.

    Science.gov (United States)

    Painter, S; Cvetkovic, V; Turner, D R

    2001-01-01

    The U.S. Department of Energy is currently studying Yucca Mountain, Nevada, as a potential site for a geological high-level waste repository. In the current conceptual models of radionuclide transport at Yucca Mountain, part of the transport path to pumping locations would be through an alluvial aquifer. Interactions with minerals in the alluvium are expected to retard the downstream migration of radionuclides, thereby delaying arrival times and reducing ground water concentrations. We evaluate the effectiveness of the alluvial aquifer as a transport barrier using the stochastic Lagrangian framework. A transport model is developed to account for physical and chemical heterogeneities and rate-limited mass transfer between mobile and immobile zones. The latter process is caused by small-scale heterogeneity and is thought to control the macroscopic-scale retardation in some field experiments. A geostatistical model for the spatially varying sorption parameters is developed from a site-specific database created from hydrochemical measurements and a calibrated modeling approach (Turner and Pabalan 1999). Transport of neptunium is considered as an example. The results are sensitive to the rate of transfer between mobile and immobile zones, and to spatial variability in the hydraulic conductivity. Chemical heterogeneity has only a small effect, as does correlation between hydraulic conductivity and the neptunium distribution coefficient. These results illustrate how general sensitivities can be explored with modest effort within the Lagrangian framework. Such studies complement and guide the application of more detailed numerical simulations.

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

    Science.gov (United States)

    Yang, Hsiaochin; Chen, Wenshan; Yeh, Changkeng

    2015-04-01

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

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

    Science.gov (United States)

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

    2010-12-01

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

  6. Drivers for the development of an alluvial fan in a high-altitude glaciated catchment

    Science.gov (United States)

    Steiner, Jakob; Miles, Evan; Ragettli, Silvan

    2016-04-01

    Alluvial fans have channelization and deposition dynamics that are not entirely understood but can have considerable impact on the local hydrological regime. Especially in high-altitude and glaciated catchments they are rather rarely investigated. During glaciological field work between 2012 and 2015 in the Langtang catchment in the Nepalese Himalaya, such an alluvial fan of ca. 0.35 km2 (4000 m a.s.l.) at the end of a very small glaciated subcatchment (~9km2) was observed. The subcatchment is the site of one of the presumed largest landslides in earth's history, that likely happened 40 000 years ago with a volume of approximately 10^10 m3 and land surface erosion is well visible. During the recent Gorkha earthquake in April 2015 (M=7.8), additional sediments were mobilized along the steep valley slopes. From 6 sets of concurrent high-resolution satellite images and DEMs between 2006 and 2015 and an additional image from 1974 we derive the evolution in space and volume of this fan and identify main sources of sediment supply. Precipitation data from a nearby Automatic Weather Station provides insight into strong rainfall events. We can compare the growth of the fan in the period without significant earthquakes until April 2014 to the change after the seismic event (image from May 2015) and after the following Monsoon season (image from October 2015) and determine dominant drivers of erosion.

  7. Hydrogeology and hydrochemistry of a shallow alluvial aquifer, western Saudi Arabia

    Science.gov (United States)

    Al-Shaibani, Abdulaziz M.

    2008-02-01

    A hydrogeological and hydrochemical study was conducted on a shallow alluvial aquifer, Wadi Wajj, in western Saudi Arabia to assess the influence of protection measures on groundwater quality. The hydrochemistry was assessed up-gradient and down-gradient from potential contamination sources in the main city in dry and wet seasons prior to and after the installation of major drainage and wastewater facilities. Wadi Wajj is an unconfined aquifer where water is stored and transmitted through fractured and weathered bedrock and the overlying alluvial sediments. Natural recharge to the aquifer is about 5% of rainfall-runoff. Hydrochemistry of the aquifer shows temporal and seasonal changes as influenced by protection measures and rainfall runoff. Both groundwater and runoff showed similar chemical signature, which is mostly of chloride-sulfate-bicarbonate and sodium-calcium type. Groundwater downstream of the city, though of poorer quality than upstream, showed significant improvement after the installation of a concrete runoff tunnel and a wastewater treatment plant. Concentrations of many of the groundwater quality indicators (e.g., TDS, coliform bacteria, and nitrate) exceed US Environmental Protection Agency drinking-water standards. Heavy metal content is, however, within allowable limits by local and international standards. The chemical analyses also suggest the strong influence of stream runoff and sewage water on the groundwater quality.

  8. Heat tracer test in an alluvial aquifer: field experiment and inverse modelling

    Science.gov (United States)

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

    2016-04-01

    Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in the recovery well and in monitoring wells. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells distributed throughout the field site (space-filling arrangement) were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume was explained by the groundwater flow gradient on the site and heterogeneity of hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with the pilot point inverse approach, main preferential flow paths were delineated.

  9. Isotopic analysis of groundwater flow systems in a wet alluvial fan, southern Nepal

    International Nuclear Information System (INIS)

    Results are reported of an isotopic and geochemical study of groundwater in wet alluvial fan deposits in the Terai Plain of southern Nepal. Local, intermediate, and regional scale groundwater flow systems are suggested by the areal and vertical distributions of the isotopes and dissolved solids along principal flow paths within the alluvial fan deposits. Most groundwater is recharged by precipitation during the annual monsoon and by the Tinau River where it leaves the Himalayan uplift. δ18O and δ2H of the groundwater range from -10.3 to -6.4 per mille and from -79 to -51 per mille, respectively (relative to SMOW), and plot on a line parallel to the global average meteoric water line. The δ18O and δ2H contents generally increase from the recharge area to the discharge area, and coincide with an increase in dissolved solids from about 100 to 400 mg/L. All groundwater is of the calcium-magnesium bicarbonate type. The tritium content of groundwater reflects variations in atmospheric bomb tritium during the past three decades. Tritium increases downgradient from approximately 20 TU in the recharge area to approximately 80 TU in the discharge area, and then decreases below detection limits (10 TU) near the southern margin of the study area. An average linear groundwater velocity of 2 to 3 metres per day, estimated from the tritium data, compares favourably with velocities determined from aquifer tests. (author). 15 refs, 3 figs, 1 tab

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

    Science.gov (United States)

    Steele, Gregory V.; Cannia, James C.

    1995-01-01

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

  11. Changes in the volume of water in the Mississippi River alluvial aquifer in the Delta, northwestern Mississippi, 1980-94

    Science.gov (United States)

    Arthur, J.K.

    1995-01-01

    The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, Office of Land and Water Resources, and the Natural Resources Conservation Service, estimated the volumetric changes of water in the Mississippi River alluvial aquifer in northwestern Mississippi from 1980 through 1994. Volumetric changes of water in the alluvial aquifer were estimated for the entire Delta and for five selected areas within the Delta. The volume of water per square mile in the alluvial aquifer in the Delta changed from 17,886 acre-feet during fall 1980 to 17,719 acre-feet during fall 1994, a decrease in volume per square mile of 167 acre-feet. The minimum volume of water per square mile in the alluvial aquifer in the Delta during 1980-94 was 17,640 acre-feet during fall 1988. Of five selected areas within the Delta, an area near Cleveland in Bolivar County had the greatest change in volume of water in the alluvial aquifer. During fall 1980 this area had 20,790 acre-feet of water per square mile in the aquifer; by fall 1994, the volume had decreased to 19,947 acre-feet of water per square mile. An area located in the vicinity of the Sunflower-Leflore County line has within its boundaries a large cone of depression in the potentiometric surface of the alluvial aquifer. The volume of water per square mile in this area decreased from 17,857 acre-feet during fall 1980 to 17,075 acre-feet during fall 1994.

  12. Impact of Fungicide Mancozeb at Different Application Rates on Soil Microbial Populations, Soil Biological Processes, and Enzyme Activities in Soil

    Directory of Open Access Journals (Sweden)

    Abhishek Walia

    2014-01-01

    Full Text Available The use of fungicides is the continuous exercise particularly in orchard crops where fungal diseases, such as white root rot, have the potential to destroy horticultural crops rendering them unsaleable. In view of above problem, the present study examines the effect of different concentrations of mancozeb (0–2000 ppm at different incubation periods for their harmful side effects on various microbiological processes, soil microflora, and soil enzymes in alluvial soil (pH 6.8 collected from apple orchards of Shimla in Himachal Pradesh (India. Low concentrations of mancozeb were found to be deleterious towards fungal and actinomycetes population while higher concentrations (1000 and 2000 ppm were found to be detrimental to soil bacteria. Mancozeb impaired the process of ammonification and nitrification. Similar results were observed for nitrifying and ammonifying bacteria. Phosphorus solubilization was increased by higher concentration of mancozeb, that is, 250 ppm and above. In unamended soil, microbial biomass carbon and carbon mineralization were adversely affected by mancozeb. Soil enzymes, that is, amylase, invertase, and phosphatase showed adverse and disruptive effect when mancozeb used was above 10 ppm in unamended soil. These results conclude that, to lessen the harmful effects in soil biological processes caused by this fungicide, addition of higher amount of nitrogen based fertilizers is required.

  13. Rheological properties of different minerals and clay soils

    Directory of Open Access Journals (Sweden)

    Dolgor Khaydapova

    2015-07-01

    Full Text Available Rheological properties of kaolinite, montmorillonite, ferralitic soil of the humid subtropics (Norfolk island, southwest of Oceania, alluvial clay soil of arid subtropics (Konyaprovince, Turkey and carbonate loess loam of Russian forest-steppe zone were determined. A parallel plate rheometer MCR-302 (Anton Paar, Austria was used in order to conduct amplitude sweep test. Rheological properties allow to assess quantitatively structural bonds and estimate structural resistance to a mechanical impact. Measurements were carried out on samples previously pounded and capillary humidified during 24 hours. In the amplitude sweep method an analyzed sample was placed between two plates. The upper plate makes oscillating motions with gradually extending amplitude. Software of the device allows to receive several rheological parameters such as elastic modulus (G’, Pa, viscosity modulus (G", Pa, linear viscoelasticity range (G’>>G”, and point of destruction of structure at which the elastic modulus becomes equal to the viscosity modulus (G’=G”- crossover. It was found out that in the elastic behavior at G '>> G " strength of structural links of kaolinite, alluvial clay soil and loess loam constituted one order of 105 Pa. Montmorillonit had a minimum strength - 104 Pa and ferrallitic soil of Norfolk island [has] - a maximum one -106 Pa. At the same time montmorillonite and ferralitic soil were characterized by the greatest plasticity. Destruction of their structure (G '= G" took place only in the cases when strain was reaching 11-12%. Destraction of the kaolinite structure happened at 5% of deformation and of the alluvial clay soil and loess loam - at 4.5%.

  14. Multiple knickpoints in an alluvial river generated by a single instantaneous drop in base level: experimental investigation

    Science.gov (United States)

    Cantelli, A.; Muto, T.

    2014-05-01

    Knickpoints often form in bedrock rivers in response to base-level lowering. These knickpoints can migrate upstream without dissipating. In the case of alluvial rivers, an impulsive lowering of base level due to, for example, a fault associated with an earthquake or dam removal commonly produces smooth, upstream-progressing degradation; the knickpoint associated with suddenly lowered base level quickly dissipates. Here, however, we use experiments to demonstrate that under conditions of Froude-supercritical flow over an alluvial bed, an instantaneous drop in base level can lead to the formation of upstream-migrating knickpoints that do not dissipate. The base-level fall can generate a single knickpoint, or multiple knickpoints. Multiple knickpoints take the form of cyclic steps, that is, trains of upstream-migrating bedforms, each bounded by a hydraulic jump upstream and downstream. In our experiments, trains of knickpoints were transient, eventually migrating out of the alluvial reach as the bed evolved to a new equilibrium state regulated with lowered base level. Thus the allogenic perturbation of base-level fall can trigger the autogenic generation of multiple knickpoints which are sustained until the alluvial reach recovers a graded state.

  15. Evaluating the controls of shear stress, sediment supply, alluvial cover, and channel morphology on experimental bedrock incision rate

    Science.gov (United States)

    Johnson, Joel P. L.; Whipple, Kelin X.

    2010-06-01

    We explored the dependence of experimental bedrock erosion rate on shear stress, bed load sediment flux, alluvial bed cover, and evolving channel morphology. We isolated these variables experimentally by systematically varying gravel sediment flux Qs and water discharge Qw in a laboratory flume, gradually abrading weak concrete "bedrock." All else held constant, we found that (1) erosion rate was insensitive to flume-averaged shear stress, (2) erosion rate increased linearly with sediment flux, (3) erosion rate decreased linearly with the extent of alluvial bed cover, and (4) the spatial distribution of bed cover was sensitive to local bed topography, but the extent of cover increased with Qs/Qt (where Qt is flume-averaged transport capacity) once critical values of bed roughness and sediment flux were exceeded. Starting from a planar geometry, erosion increased bed roughness due to feedbacks between preferential sediment transport through interconnected topographic lows, focused erosion along these zones of preferential bed load transport, and local shear stresses that depended on the evolving bed morphology. Finally, continued growth of bed roughness was inhibited by imposed variability in discharge and sediment flux, due to changes in spatial patterns of alluvial deposition and impact wear. Erosion was preferentially focused at lower bed elevations when the bed was cover-free, but was focused at higher bed elevations when static alluvial cover filled topographic lows. Natural variations in discharge and sediment flux may thus stabilize and limit the growth of roughness in bedrock channels due to the effects of partial bed cover.

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

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    2013-12-01

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

  17. Experimental and numerical findings on the long-term evolution of migrating alternate bars in alluvial channels

    NARCIS (Netherlands)

    Crosato, A.; Desta, F.B.; Cornelisse, J.; Schuurman, F.; Uijttewaal, W.S.J.

    2012-01-01

    Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether migrating bars eventually re

  18. Groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri, well field

    Science.gov (United States)

    Wilkison, Donald H.

    2012-01-01

    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.

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

    Science.gov (United States)

    Ninfo, Andrea; Mozzi, Paolo; Abbà, Tiziano

    2016-05-01

    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 survey was conducted with soil observation, 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 (geotechnical analysis, the estimation of buried archeological deposits in the city center, and the assessment of flooding hazard.

  20. Geophysical and Hydrological Characterization of Alluvial Fans in the Valle El Sauz Encinillas, Chihuahua, México.

    Science.gov (United States)

    Villalobos-Aragón, A.; Chávez-Aguirre, R.; Osuna-Vizcarra, A.; Espejel-García, V. V.

    2007-05-01

    The Valle El Sauz Encinillas (VESE) is located 92 km north of Chihuahua City, México. Despite being the principal aquifer feeding Chihuahua City, and being flanked by two well studied geological features (Bloque Calera-Del Nido to the West, and the Sierra Peña Blanca to the East), a lack of available hydrogeological data prevails in the valley. The goals of this study are two: 1) geomorphometrical analysis of the sub-basins and alluvial fans, and 2) determination of the alluvial fan geoelectrical units via electrical-resistivity soundings. The Basin and Range system forms a closed sub-basin with a lacustrine basin system in extinction process. The aquifer is located in alluvial Quaternary sediments, with varying granulometry, reaching a thickness of 600 meters at the center of the valley. The biggest alluvial fan in the VESE is located at the Cañón de Santa Clara, and intersects the playa-lake deposits of the Laguna de Encinillas. This fan has a surface of 73.2 km2 and an average slope of 0.437°. The geomorphometrical analysis included the sub-basins, currents, and the fans in the area. These analyses allow a comparison between alluvial fans in the VESE and those in Death Valley, California, USA. The alluvial fans in both areas show a similar behavior in all plots. Twenty electrical resistivity soundings (Schlumberger array, AB/2 distance of 400 m) were performed in the alluvial fan. The basement and four other geoelectrical units were identified in the fan. The geophysical data, granulometric determinations, plus geochemical information of twelve wells in the area were analyzed. These data show how the decrease in granulometry, both frontally and laterally in the fan, results in a rise of the hydraulic conductivity and transmisivity values (water wells in Los Sauces and El Faro). However, both the permeability and the water quality in its distal portion, are affected by the playa lake deposits, the raising ratio of clay-size sediments (and evaporites) in the

  1. Discharge estimation from planform characters of the Shedhi River, Gujarat alluvial plain: Present and past

    Indian Academy of Sciences (India)

    Alpa Sridhar

    2007-08-01

    In the absence of long-term hydrologic and streamflow records an understanding of river morphology (present and past) can help delineate changes in magnitudes of water and sediment discharges. The relict drainage system of Gujarat alluvial plain provides an opportunity to reconstruct the palaeochannel morphology-related discharge estimations. In this paper, based on the geomorphological evidence and channel geometry, an attempt has been made to reconstruct the palaeohydrological condition in the Shedhi River during the Holocene. A comparison of the present day channel of the Shedhi River with that of its palaeo counterpart reveals that the former was carrying much higher bankfull discharge (∼5500m3s−1) as compared to the present (∼200m3s−1). This is attributed to a larger drainage area and enhanced precipitation in the Shedhi River basin.

  2. Steady-state numerical groundwater flow model of the Great Basin carbonate and alluvial aquifer system

    Science.gov (United States)

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

    2014-01-01

    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.

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

    Science.gov (United States)

    Wang, R.; Luo, Y.; Yang, Y.; Tian, F.; Zhou, Y.; Tian, M.-Z.

    2015-11-01

    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.

  4. Alluvial fans and megafans along the southern side of the Alps

    Science.gov (United States)

    Fontana, Alessandro; Mozzi, Paolo; Marchetti, Mauro

    2014-03-01

    The foreland basin of the southern European Alps is characterized by large fan-shaped alluvial systems fed by the main montane valleys and these depositional systems present an extent of 300-3000 km2, with a length of 30-70 km. Most of them are megafans, characterized by evident longitudinal differentiation in which steep piedmont sector consists of amalgamated gravels, while the distal portion has a gradient Garda Lake, their downstream development was limited by the Po River plain. The thickness of LGM alluvial sedimentation ranges between 30 and 15 m and pinches out about 25 km off the present coast. Soon after ice decay, after 19-17 kyr cal BP, sediment delivery from Alpine catchments to the plain dramatically decreased and in the central Alps large intramontane lakes formed, trapping almost all the bedload. Thus, the ratio between sediment and water discharge dramatically decreased and an erosive phase affected the LGM megafans and fans, leading the rivers to entrench for tens of meters. The funneling effect created by the fluvial incisions allowed the gravels to arrive tens of kilometers further downstream than in the LGM. In the Venetian-Friulian megafans a single valley formed in the piedmont sector, while 2-5 incised valleys developed in the distal sector. These latter valleys have been almost completely filled by a depositional lobe formed in the last 8 kyr, partly triggered by Holocene sea-level rise. The Alpine tributaries of the river Po still flow along a single incised valley from their megafan apex to the junction with the Po and they have not yet been affected by sea-level influence.

  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.

    2015-02-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  8. Tracing stream leakage towards an alluvial aquifer in a mountain basin using environmental isotopes

    International Nuclear Information System (INIS)

    Highlights: ► Spring data define the altitudinal isotopic gradient in the Montseny-Guilleries area. ► Runoff isotopes are defined by the altitudinal gradient and the hypsometric curve. ► Head data alone are not sufficient to define the stream–aquifer relationship. ► Stream isotopic values are thus key in identify stream recharge to the aquifer. - Abstract: Stream–aquifer relationships in mountain basins are of great relevance because they control the water balance and, with it, the amount of resources (whether surface water or ground water) available for ecological and human demands. In this paper, this relationship is studied using environmental isotopes (δ18O and δD) to identify the occurrence of stream recharge in the Arbúcies River basin (NE Spain). Isotopic data from 51 natural springs define the local altitudinal gradient. This function is weighted by the proportional area above each point, given by the hypsometric curve, in order to estimate the isotopic stream water content as the contribution of runoff from incremental elevations. Stream water isotopes from two surveys are compared with hypsometrically averaged isotopic values to check for the appropriateness of this approach. Results show that it is more suitable when subsurface flows from surface formations, such as alluvial deposits, are the main contributors to stream discharge than when it derives from a single rainfall event. The characterization of stream isotope values is used as a key factor in identifying stream leakage to an unconfined alluvial aquifer in the lower reach of the Arbúcies River

  9. Soil compaction in forest soils

    OpenAIRE

    TURGUT, Bülent

    2012-01-01

    Soil compaction is a widespread degradation process in forest sites. Soil degradation occurring on the structural formation of a natural soil system by rainfall or mechanical outer forces generally results in soil particles to be rearranged tighter than its previous status. In this case, soil compaction -defined as the increase in bulk density of soil- develops with negative effects on soil-plant-water relations. With the compaction, the density of soil increases while the porosity rate decre...

  10. Degradation of 14C ring labeled pesticides in selected soils of Sri Lanka

    International Nuclear Information System (INIS)

    Degradation rates of 14C ring labeled carbofuran and diazinon in selected Sri Lankan soils were studied using 0.1 μCi/10 g soil in Nuwara Eliya (red yellow podzolic), Pugoda (alluvials) Kalpitiya and Negombo (regosols) soils by incubating at 28 deg C of temperature for 13 hours light and 11 hours dark conditions and measuring the activity of liberated CO2 using liquid scintillation counter after 0, 1, 3, 5, 7, 14, 28, 36, 42 and 58 days. During the total period the carbofuran mineralization was about 23% in Kalpitiya soils and less than 20% in other three soils and diazinon mineralization was about 25% in Negombo soil and very low in other soils. (author)

  11. Effect of simazine and atrazine on the decomposition of 14C-glucose in soil

    International Nuclear Information System (INIS)

    The effect of two triazine herbicides, simazine and atrazine on the decomposition of 14C-glucose in an alluvial soil was studied in a laboratory incubation experiment. During 234-days incubation the soil, where no herbicide was applied with glucose, lost 72 percent of the radiocarbon as 14CO2, while the soil treated with simazine and atrazine lost 50.5 and 17.5 percent, respectively. The evolution of 14CO2 increased sharply after the addition of glucose to the soil and it declined after 60 days. In humic acid and humin fractions of soil organic matter, the percentage of applied carbon was found to be more in soil treated with herbicides as compared to untreated glucose amended soil. (author)

  12. Long-term interactions between man and the fluvial environment - case of the Diyala alluvial fan, Iraq

    Science.gov (United States)

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

    2014-05-01

    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

  13. Soil Formation and Taxonomy in Yeşilırmak River Terraces

    OpenAIRE

    Alper Durak; Mehmet Erdem Aydın

    2014-01-01

    In this study, the soils of which parent material is alluvial and formed Yeşilırmak river terraces were investigated. For this purposes four different profiles were excavated in the study area. Then twenty-seven soil samples were taken from horizons of four profiles and their physical and chemical analyses were done for soil taxonomy research. Profile of Kumocagi and Cakil were classified in subgroup as Typic Ustipsamments, Havaalanı and Mera profiles were classified Typic Haplustolls and Typ...

  14. Debris flow dominated alluvial fans in the Australian high country indicate that landscape denudation through the Holocene has been dominated by post-bushfire runoff events

    Science.gov (United States)

    Marren, Philip; Nyman, Petter; Kermode, Stephanie

    2016-04-01

    Bushfires play a major role in shaping landscapes across the globe. Whilst the role of fire in shaping and changing vegetation assemblages is relatively well understood, there is still debate about the significance of fire in driving landscape denudation, relative to other processes, such as major rainfall and flood events and questions remain about the frequency of extreme fire events over longer timescales in response to climate forcing. Studies of post-fire landscape impact of recent bushfires in southeast Australia indicate that where storm events occur shortly after a major bushfire, hillslope erosion is enhanced, due to debris flows and erosion of both primary hillslope sediment and sediment stored in hillslope channel networks. In Australia, knowledge of long-term bushfire frequency is largely derived from pollen and micro-charcoal records in lake-sediment archives and is not directly relevant to resolving questions regarding fire impacts on landscape denudation and sediment transfer. We excavated trenches in four alluvial fans at the base of hillslopes in the high country of northeast Victoria, Australia. This area was burnt by bushfires in 1939 and 2003, and regional climate and hydrology are strongly controlled by El Niño. The trenches were up to 3.5m deep, and in most cases intersected underlying floodplain sediment at the base of the trench, indicating that they provide a full record of sedimentation for that sector of the fan. Fan stratigraphy consisted of sub-horizontal (parallel to the fan surface) units 0.3-0.5m thick, with occasional units 1-1.2m thick, and cross-cutting channelized units. Debris flow deposits accounted for 70-80% of the observed sediments, with water-laid gravels and soil units forming the remainder. Most soil layers were burnt, and most (but not all) debris flow units contained charcoal. A typical stratigraphy consisted of 6-8 debris flow units per fan, with four units containing a fire signature or overlying a burnt soil layer

  15. Soil formation in the Tsauchab Valley, Namibia

    Science.gov (United States)

    Eden, Marie; Bens, Oliver; Ramisch, Arne; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The BMBF-funded project GeoArchives (Spaces) investigates soils and sediments in Southern Africa. A focus area lies on the Tsauchab Valley (Namibia), South of the Naukluft mountain range (24°26'40'' S, 16°10'40'' E). On a gently sloping alluvial fan facing East towards the river, the surface is characterized by a desert pavement covering soils used as farmland. The landscape units were mapped and the area at the lower slope of a hill was divided into three units: a rinsing surface and a gravel plain, separated by a channel. On these surfaces soil profiles were excavated. Profile description followed the German system (Bodenkundliche Kartieranleitung KA 5) and disturbed samples were taken at various depths and analysed in the lab. Undisturbed soil cores with a volume of 100 cm³ were taken just below the surface at a depth of ~1-6 cm. Lab analyses included texture and gravel content, colour, pH, electrical conductivity, carbonates, CNS, cation exchange capacity, pedogenic oxides, main and trace elements (XRF), and clay mineral distribution (XRD). Undisturbed samples were used to determine soil water retention curve, air permeability and bulk density. The profiles revealed moderately developed cambic soils rich in clay minerals and with total carbon contents ranging up to 1.8 %, bearing shrubs and after episodic rainfall a dense grass vegetation. Their genesis is discussed and interpreted in the context of the landscape and climate history of this semi-desert environment.

  16. The use of extremal hypotheses as a means of predicting alluvial channel dimensions for river restoration

    Science.gov (United States)

    Tranmer, A.; Goodwin, P.

    2013-12-01

    In designing fluvial infrastructure and restoration projects the question often arises, what are the cross sectional characteristics of width, depth, roughness, and slope necessary to ensure no net aggradation or degradation occurs within a given reach of river? Current fluvial design utilizes empirical and numerical methods to calculate the required slope and geometry of alluvial channels; however, no solution has been proposed that fully incorporates the necessary 3-dimensional mechanics of open channels due to the complicated processes and feedbacks that occur during mobile bed conditions. This is further compounded by numerous local geologic constraints and perturbations that must be considered, which interrupt the evolution towards a balance of deposition and erosion, or the condition of dynamic-equilibrium. However, given the moderate success of power law relations, such as regime theory and hydraulic geometry, it is evident self-organizing processes are present in watersheds that scale channel size and sinuosity to some average condition in order to maintain a balance of fluid and sediment flux from the upstream catchment. Extremal hypotheses have been developed as an alternative to solving the reach scale 3-dimensional conservation laws for fluid and sediment, to provide a first order means of predicting channel dimensions in an objective and reproducible manner. This study evaluates the performance of extremal hypotheses in identifying the trend towards dynamic-equilibrium over unique spatial gradients in 2 gravel-bed river systems. Using a location-for-time-substitution approach, extremal hypotheses were examined over a longitudinal gradient of channel evolution towards reaches found to be near equilibrium in an unconfined, transport-limited river in the undisturbed rain forest of Chilean Patagonia and a supply-limited, semi-confined canyon system in Central Idaho, USA. Field data from these two sites imply alluvial systems attempt to minimize their

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

    Science.gov (United States)

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

    1984-01-01

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

  18. Channel migration patterns and related sequences in some alluvial fan systems

    Science.gov (United States)

    Viseras, C.; Fernández, J.

    1994-01-01

    The pendular displacement of a channel system, consisting of an area of higher channel density (trunk channel zone) on both sides of which channel density progressively decreases (secondary channel zone), can, under favourable subsidence conditions, lead to the development of alluvial fans. Characteristic sequences are found in these fans, depending on their position in the sedimentary body. A marginal position in the fan is thus recognized by the superposition of fining and thinning upwards (FTU) cycles, the upper part of which is made up of important thicknesses of overbank fines, all the backsets of bars dipping in the same direction (towards the centre of the cone). On the other hand, a central position is characterized by a higher number of FTU cycles, which are incomplete due to erosion of the upper parts (corresponding to the higher concentration of overbank fines), and the backsets in each cycle dip alternately in opposite directions. The displacement of the channel system in a constant direction may be caused by the preferential accumulation of bars on one of the banks of the channel. The change in migratory direction giving rise to the pendular movement is caused by the trunk channel reaching the basin margin or the sedimentation area of an adjoining fan. Palaeogeographic reconstructions of fans using this technique contribute to the analysis of ancient basins: small-radius fans with a high sweep angle (A S) are characteristic of basin margins subjected to a low sediment supply/subsidence ratio (S S /S B), whereas large-radius fans with a low A S characterize periods with a high S S /S B ratio on the basin margin. This model can be applied in economic geology studies, as the location of an ancient cone permits delimitation of the axial strip (with a higher proportion of coarse, highly porous, channelled facies) and the marginal sectors (where thick layers of less porous overbank fines are intercalated). We here present the example of the alluvial fans in

  19. Microchemical signature of alluvial gold from two contrasting terrains in Cameroon

    Science.gov (United States)

    Omang, B. O.; Suh, C. E.; Lehmann, B.; Vishiti, A.; Chombong, N. N.; Fon, A. N.; Egbe, J. A.; Shemang, E. M.

    2015-12-01

    The microchemical signature of alluvial gold particles has wide application in constraining their primary sources. In this study, we apply this concept to investigate the composition of gold-bearing alloys from alluvial samples draining two geologically distinct terrains in southern and eastern Cameroon where the search for primary gold has remained elusive. The first set of gold grains (Lom grains) are from the Lom river drainage system with predominantly metasedimentary Pan-African rocks in the catchment region while the second set of grains (Nyong grains) are from the Mbal and Ebap tributaries of the Nyong river draining over a Paleoproterozoic complex comprising metamorphosed ultramafic rocks, amphibolites and granulitic gneisses. The gold grains recovered from these fluvial networks after panning were first studied under an electron microscope in order to evaluate their morphological features and subsequently embedded in epoxy resin, polished, and their compositions determined by both electron microprobe (EMPA) and laser ablation (LA-ICP-MS) techniques. The Lom grains are irregular to sub rounded with extensively pitted surfaces while the Nyong grains are predominantly rounded, oblong and with smooth surfaces. Nyong grains are devoid of inclusions while galena and pyrite are entombed in the Lom grains. Both set of grains are essentially Au-Ag alloys although the Ag content of the cores of the Nyong grains from both EMPA and LA-ICP-MS analytical techniques are significantly lower (0.05-6.07 wt% Ag; 93.54-99.29 wt% Au) than for Lom gold (0.06-22.75 wt% Ag; 78.76-99.86 wt% Au). X-ray element distribution maps do not show any zonal variation in core composition suggesting the gold grains derived from lode sources with single episode of hydrothermal gold deposition. Also the Nyong grains have significant amounts of Pt, Pd and Cr suggesting a link with ultramafic rocks while the Lom grains have substantial Sb and Zn levels pointing to hydrothermal quartz veining as

  20. Effects of Field-Scale Heterogeneity on Plume Behavior and Remediation in Alluvial Aquifer Systems

    Science.gov (United States)

    Lee, S.; Labolle, E. M.; Fogg, G. E.

    2002-12-01

    This study examines the effects of various field-scale geologic attributes on plume behavior and efficacy of remediation. Using transition probability geostatistical simulation and core descriptions available from the Lawrence Livermore National Laboratory site, we generate a spectrum of unconditional realizations representing alluvial aquifer systems with different degrees of interconnectedness (connectivity) and volumetric abundance of different facies. Both statistical and spatial measures are used to characterize degree of connectivity of high-K bodies (channel facies) in simulated K fields. The random-walk particle method is used to simulate conservative mass transport under steady-state flow conditions. Spatial and temporal analyses of simulated contaminant plumes explore the relative sensitivity of plume behavior to style of geologic complexity. Two geologic settings (one with high-K embedded in low-K materials and the other with low-K embedded in high-K) are used to evaluate a set of remedial methods for different proportions and corresponding degrees of connectivity. The remedial scenarios include ambient transport (no remediation), pump-and-treat remediation with three different rates of extraction, and two methods of enhanced remediation. Results show a percolation threshold for high-K channel bodies between channel fractions of 0.08 and 0.18. Further, as the volume fraction of high-K channel facies increases (from 0.08 to 0.68), simulated plumes show decreasingly anomalous behavior (e.g., mass holdback resulting in tailing). Results show that the architecture of high permeability units and preferential flow paths are important in controlling groundwater flow in fine-grain dominant systems, and relatively less important in coarse-grain dominant systems. Remedial experiments show total mass remaining in low-K materials after the application of remediation is always greater than the total mass in high-K channel facies at the channel facies volume fraction

  1. Landscape level reforestation priorities for forest breeding landbirds in the Mississippi Alluvial Valley

    Science.gov (United States)

    Twedt, D.J.; Uihlein, W.B., III

    2005-01-01

    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

  2. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in...

  3. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge rate for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in...

  4. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant hydraulic conductivity value for the alluvial and terrace deposits along the North Canadian River from...

  5. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the alluvial and terrace deposits along the Cimarron River from Freedom to...

  6. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the North Canadian River from Canton Lake to...

  7. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake...

  8. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern...

  9. 1:1,000,000-scale hydrographic areas and flow systems for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a U.S. Geological Survey (USGS) study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer...

  10. 1:1,000,000-scale potentiometric contours and control points for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a U.S. Geological Survey (USGS) study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer...

  11. Three-dimensional hydrogeologic framework for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  12. Selected Basin Characterization Model Parameters for the Great Basin Carbonate and Alluvial Aquifer System of Nevada, Utah, and Parts of Adjacent States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on ground-water resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  13. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the Cimarron River in northwestern Oklahoma during...

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

    KAUST Repository

    Hanafy, Sherif M.

    2014-08-05

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

  15. A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

    Directory of Open Access Journals (Sweden)

    D. Kocman

    2010-02-01

    Full Text Available Results obtained by a laboratory flux measurement system (LFMS focused on investigating the kinetics of the mercury emission flux (MEF from contaminated soils of the Idrija Hg-mine region, Slovenia are presented. Representative soil samples with respect to total Hg concentrations (4–417 μg g−1 and land cover (forest, meadow and alluvial soil alongside the River Idrijca were analysed to determine the variation in MEF versus distance from the source, regulating three major environmental parameters comprising soil temperature, soil moisture and solar radiation. MEFs ranged from less than 2 to 530 ng m−2 h−1, with the highest emissions from contaminated alluvial soils and soils near the mining district in the town of Idrija. A significant decrease of MEF was then observed with increasing distance from these sites. The results revealed a strong positive effect of all three parameters investigated on momentum MEF. The light-induced flux was shown to be independent of the soil temperature, while the soil aqueous phase seems to be responsible for recharging the pool of mercury in the soil available for both the light- and thermally-induced flux. The overall flux response to simulated environmental conditions depends greatly on the form of Hg in the soil. Higher activation energies are required for the overall process to occur in soils where insoluble cinnabar prevails compared to soils where more mobile Hg forms and forms available for transformation processes are dominant.

  16. Use and utility of combined solute and heat tracer tests for characterizing hydrogeothermal properties of an alluvial aquifer

    OpenAIRE

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

    2015-01-01

    Using heat as a tracer together with a solute tracer is interesting for characterizing hydrogeothermal properties of the underground. These properties are particularly needed to dimension any low temperature geothermal project using an open doublet system (pumping-reinjection) in a shallow aquifer. The tracing experiment, conducted in the alluvial aquifer of the River Meuse (Hermalle near Liège), consisted in injecting simultaneously heated water at 40°C and a dye tracer in a piezometer and m...

  17. A multiple-point geostatistical method for characterizing uncertainty of subsurface alluvial units and its effects on flow and transport

    Science.gov (United States)

    Cronkite-Ratcliff, C.; Phelps, G.A.; Boucher, A.

    2012-01-01

    This report provides a proof-of-concept to demonstrate the potential application of multiple-point geostatistics for characterizing geologic heterogeneity and its effect on flow and transport simulation. The study presented in this report is the result of collaboration between the U.S. Geological Survey (USGS) and Stanford University. This collaboration focused on improving the characterization of alluvial deposits by incorporating prior knowledge of geologic structure and estimating the uncertainty of the modeled geologic units. In this study, geologic heterogeneity of alluvial units is characterized as a set of stochastic realizations, and uncertainty is indicated by variability in the results of flow and transport simulations for this set of realizations. This approach is tested on a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. Yucca Flat was chosen as a data source for this test case because it includes both complex geologic and hydrologic characteristics and also contains a substantial amount of both surface and subsurface geologic data. Multiple-point geostatistics is used to model geologic heterogeneity in the subsurface. A three-dimensional (3D) model of spatial variability is developed by integrating alluvial units mapped at the surface with vertical drill-hole data. The SNESIM (Single Normal Equation Simulation) algorithm is used to represent geologic heterogeneity stochastically by generating 20 realizations, each of which represents an equally probable geologic scenario. A 3D numerical model is used to simulate groundwater flow and contaminant transport for each realization, producing a distribution of flow and transport responses to the geologic heterogeneity. From this distribution of flow and transport responses, the frequency of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary.

  18. Overlapping of pedogenesis and meteoric diagenesis in distal alluvial and shallow lacustrine deposits in the Madrid Miocene Basin, Spain

    OpenAIRE

    Bustillo, María Ángeles; Alonso-Zarza, Ana María

    2007-01-01

    The Miocene distal alluvial fan and palustrine deposits of the Madrid Basin (Paracuellos de Jarama area) were examined to establish the sequence of its pedogenic–diagenetic processes and the main factors controlling them. In this area the diagenetic processes operated not only on carbonates, as commonly studied, but also in high magnesium clays and opaline cherts. This paper provides a dynamic model for saline–alkaline lake margins that complements the existing freshwater palustrine ...

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

    Science.gov (United States)

    Madole, Richard F.

    2012-09-01

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

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

    Science.gov (United States)

    Madole, Richard F.

    2012-01-01

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

  1. Identification of recharge zones in the Lower Mississippi River alluvial aquifer using high-resolution precipitation estimates

    Science.gov (United States)

    Dyer, Jamie; Mercer, Andrew; Rigby, James R.; Grimes, Alexandria

    2015-12-01

    Water resources in the lower Mississippi River alluvial valley play a critical role in agricultural productivity due to the widespread use of irrigation during the growing season. However, the unknown specifics of surface-atmosphere feedbacks in the region, along with diminishing groundwater availability and the non-sustainable trend in irrigation draws from the alluvial aquifer, makes it difficult for water resource managers to make sound decisions for future water sustainability. As a result, it is crucial to identify spatial and temporal associations between local rainfall patterns and groundwater levels to determine the influence of precipitation on regional aquifer recharge. Specifically, it is critical to define the recharge zones of the aquifer so that rainfall distribution can be used to assess potential groundwater recovery. This project addresses the issue of defining areas of recharge in the lower Mississippi River alluvial aquifer (LMRAA) through an assessment of historical precipitation variability using high-resolution radar-derived precipitation estimates. A rotated principal component analysis (RPCA) of both groundwater and precipitation data from October through April is used to define locations where aquifer levels show the greatest variability, with a stepwise regression approach used to define areas where rainfall and groundwater levels show the strongest association. Results show that the greatest recharge through direct rainfall is along the Tallahatchie River basin in the northeastern Mississippi Delta, with recharge along the periphery of the LMRAA likely a result of direct water flux from surface hydrologic features.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Tectonic controls on the geomorphic evolution of alluvial fans in the Piedmont Zone of Ganga Plain, Uttarakhand, India

    Indian Academy of Sciences (India)

    Pradeep K Goswami; Charu C Pant; Shefali Pandey

    2009-06-01

    The Piedmont Zone is the least studied part of the Ganga Plain.The northern limit of the Piedmont Zone is defined by the Himalayan Frontal Thrust (HFT)along which the Himalaya is being thrust over the alluvium of the Ganga Plain.Interpretation of satellite imagery,Digital Terrain Models (DTMs)and field data has helped in the identification and mapping of various morpho-tectonic features in the densely forested and cultivated Piedmont Zone in the Kumaun region of the Uttarakhand state of 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 aggradation processes in the area are mainly controlled by the ongoing tectonic activities.Such activities along the HFT and transverse faults have controlled the accommodation space by causing differential subsidence of the basin,and aggradation processes by causing channel migration,channel incision and shifting of depocentres.The active tectonic movements have further modified the landscape of the area in the form of tilted alluvial fan,gravel ridges,terraces and uplifted gravels.

  4. Hierarchy in factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    Science.gov (United States)

    Dembkowski, D.J.; Miranda, L.E.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts. ?? 2011 Springer Science+Business Media B.V.

  5. Factors affecting fish biodiversity in floodplain lakes of the Mississippi Alluvial Valley

    Science.gov (United States)

    Miranda, Leandro E.; Dembkowski, Daniel J.

    2012-01-01

    River-floodplain ecosystems offer some of the most diverse and dynamic environments in the world. Accordingly, floodplain habitats harbor diverse fish assemblages. Fish biodiversity in floodplain lakes may be influenced by multiple variables operating on disparate scales, and these variables may exhibit a hierarchical organization depending on whether one variable governs another. In this study, we examined the interaction between primary variables descriptive of floodplain lake large-scale features, suites of secondary variables descriptive of water quality and primary productivity, and a set of tertiary variables descriptive of fish biodiversity across a range of floodplain lakes in the Mississippi Alluvial Valley of Mississippi and Arkansas (USA). Lakes varied considerably in their representation of primary, secondary, and tertiary variables. Multivariate direct gradient analyses indicated that lake maximum depth and the percentage of agricultural land surrounding a lake were the most important factors controlling variation in suites of secondary and tertiary variables, followed to a lesser extent by lake surface area. Fish biodiversity was generally greatest in large, deep lakes with lower proportions of watershed agricultural land. Our results may help foster a holistic approach to floodplain lake management and suggest the framework for a feedback model wherein primary variables can be manipulated for conservation and restoration purposes and secondary and tertiary variables can be used to monitor the success of such efforts.

  6. Valuing ecosystem services from wetlands restoration in the Mississippi Alluvial Valley

    Science.gov (United States)

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

    2010-01-01

    This study assesses the value of restoring forested wetlands via the U.S. government's Wetlands Reserve Program (WRP) in the Mississippi Alluvial Valley by quantifying and monetizing ecosystem services. The three focal services are greenhouse gas (GHG) mitigation, nitrogen mitigation, and waterfowl recreation. Site- and region-level measurements of these ecosystem services are combined with process models to quantify their production on agricultural land, which serves as the baseline, and on restored wetlands. We adjust and transform these measures into per-hectare, valuation-ready units and monetize them with prices from emerging ecosystem markets and the environmental economics literature. By valuing three of the many ecosystem services produced, we generate lower bound estimates for the total ecosystem value of the wetlands restoration. Social welfare value is found to be between $1435 and $1486/ha/year, with GHG mitigation valued in the range of $171 to $222, nitrogen mitigation at $1248, and waterfowl recreation at $16. Limited to existing markets, the estimate for annual market value is merely $70/ha, but when fully accounting for potential markets, this estimate rises to $1035/ha. The estimated social value surpasses the public expenditure or social cost of wetlands restoration in only 1 year, indicating that the return on public investment is very attractive for the WRP. Moreover, the potential market value is substantially greater than landowner opportunity costs, showing that payments to private landowners to restore wetlands could also be profitable for individual landowners. ?? 2009 Elsevier B.V.

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

    Science.gov (United States)

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

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

  8. DAM IMPACTS ON AND RESTORATION OF AN ALLUVIAL RIVER - RIO GRANDE, NEW MEXICO

    Institute of Scientific and Technical Information of China (English)

    Gigi RICHARD; Pierre JULIEN

    2003-01-01

    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 Mexico, provides an excellent case study of river regulation, channel adjustments, and restoration efforts. Cochiti Dam was constructed on the main stem of the Rio Grande in 1973 for flood control and sediment retention. Prior to dam construction, the Rio Grande was a wide, sandy braided river. Following dam construction, the downstream channel bed degraded and coarsened to gravel size, and the planform shifted to a more meandering pattern. Ecological implications of the geomorphic changes include detachment of the river from the floodplain, reduced recruitment of riparian cottonwoods, encroachment of non-native saltcedar and Russian olive into the floodplain, and degraded aquatic habitat for the Rio Grande silvery minnow.Recent restoration strategies include removal of non-native riparian vegetation, mechanical lowering of floodplain areas, and channel widening.

  9. Spatial variation in microbial community structure, richness, and diversity in an alluvial aquifer.

    Science.gov (United States)

    Medihala, P G; Lawrence, J R; Swerhone, G D W; Korber, D R

    2012-09-01

    Relatively little is known regarding the spatial variability of microbial communities in aquifers where well fouling is an issue. In this study 2 water wells were installed in an alluvial aquifer located adjacent to the North Saskatchewan River and an associated piezometer network developed to facilitate the study of microbial community structure, richness, and diversity. Carbon utilization data analysis revealed reduced microbial activity in waters collected close to the wells. Functional PCR and quantitative PCR analysis indicated spatial variability in the potential for iron-, sulphate-, and nitrate-reducing activity at all locations in the aquifer. Denaturing gradient gel electrophoresis analysis of aquifer water samples using principal components analyses indicated that the microbial community composition was spatially variable, and denaturing gradient gel electrophoresis sequence analysis revealed that bacteria belonging to the genera Acidovorax , Rhodobacter , and Sulfuricurvum were common throughout the aquifer. Shannon's richness (H') and Pielou's evenness (J') indices revealed a varied microbial diversity (H' = 1.488-2.274) and an even distribution of microbial communities within the aquifer (J' = 0.811-0.917). Overall, these analyses revealed that the aquifer's microbial community varied spatially in terms of composition, richness, and metabolic activity. Such information may facilitate the diagnosis, prevention, and management of fouling. PMID:22913282

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

    Directory of Open Access Journals (Sweden)

    K. Edmaier

    2011-01-01

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

  11. Radial mosaic internal structure of rounded diamond crystals from alluvial placers of Siberian platform

    Science.gov (United States)

    Ragozin, A. L.; Zedgenizov, D. A.; Kuper, K. E.; Shatsky, V. S.

    2016-07-01

    The specific gray to almost black diamonds of rounded morphology are especially typical in alluvial placers of the northeastern part of the Siberian platform. The results of study of internal structure of these diamonds are presented. X-ray topography and birefringence patterns of polished plates of studied diamonds show their radial mosaic structure. Diamonds consists of slightly misorientated (up to 20') subindividuals which are combined to mosaic wedge-shaped sectors. Electron back-scatter diffraction technique has demonstrated that subindividuals are often combined in the single large blocks (subgrains). The whole crystals commonly consist of several large subgrains misoriented up to 5° to one another. The total nitrogen content of these diamonds vary in the range 900-3300 ppm and nitrogen aggregation state (NB/(NB + NA)*100) from 25 to 64 %. Rounded diamond crystals of variety V are suggested to have been formed at the high growth rate caused by the high oversaturation of carbon in the crystallization medium. It may result in the splitting of growing crystal and their radial mosaic structure as a sequence. High content of structural nitrogen defects and the great number of mechanical impurities - various mineral and fluid inclusions may also favor to generation of this structure.

  12. Seismic site effects in a deep alluvial basin: numerical analysis by the boundary element method

    CERN Document Server

    Semblat, Jean-François; Dangla, Patrick; 10.1016/S0266-352X(02)00017-4

    2009-01-01

    The main purpose of the paper is the numerical analysis of seismic site effects in Caracas (Venezuela). The analysis is performed considering the boundary element method in the frequency domain. A numerical model including a part of the local topography is considered, it involves a deep alluvial deposit on an elastic bedrock. The amplification of seismic motion (SH-waves, weak motion) is analyzed in terms of level, occurring frequency and location. In this specific site of Caracas, the amplification factor is found to reach a maximum value of 25. Site effects occur in the thickest part of the basin for low frequencies (below 1.0 Hz) and in two intermediate thinner areas for frequencies above 1.0 Hz. The influence of both incidence and shear wave velocities is also investigated. A comparison with microtremor recordings is presented afterwards. The results of both numerical and experimental approaches are in good agreement in terms of fundamental frequencies in the deepest part of the basin. The boundary elemen...

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

    Directory of Open Access Journals (Sweden)

    K. Edmaier

    2011-05-01

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

  14. A RESEARCH ON SOIL FERTILITY AND OTHER PROBLEMS AT BURHANİYE VICINITY

    Directory of Open Access Journals (Sweden)

    Mehmet ŞAHİN

    1995-03-01

    Full Text Available The research was carried out with aim of determining fertility and other problems in the vicinity of Burhaniye. The research soils are alluvial soils. The climate is moderate and semi humid. The vegetation are agricultural plants. The topography is almost smooth. Dominant soil farming processes are weak calcification and podsolization, eluviasyon, illuviasyon, loss, translocation and synthesis. The aspect of horizonation is weak. Hydraulic conductivity classes are moderately slow, medium and moderately speed. Drainage classes are medium and poor. Texture classes are medium, moderately fine and fine. These soils are insaline soils. Reaction classes are slightly alkali and moderately alkali. Calcareous classes are trace, few and moderately few. Organic matter classes are very few, few, medium and high. Phosphorus and potassium classes are very few, few, medium and high. In addition some fertility, soil management and other related problems are exist. For example forming of compacting and plow pan.

  15. Using geochemical indicators to distinguish high biogeochemical activity in floodplain soils and sediments.

    Science.gov (United States)

    Kenwell, Amy; Navarre-Sitchler, Alexis; Prugue, Rodrigo; Spear, John R; Hering, Amanda S; Maxwell, Reed M; Carroll, Rosemary W H; Williams, Kenneth H

    2016-09-01

    A better understanding of how microbial communities interact with their surroundings in physically and chemically heterogeneous subsurface environments will lead to improved quantification of biogeochemical reactions and associated nutrient cycling. This study develops a methodology to predict potential elevated rates of biogeochemical activity (microbial "hotspots") in subsurface environments by correlating microbial DNA and aspects of the community structure with the spatial distribution of geochemical indicators in subsurface sediments. Multiple linear regression models of simulated precipitation leachate, HCl and hydroxylamine extractable iron and manganese, total organic carbon (TOC), and microbial community structure were used to identify sample characteristics indicative of biogeochemical hotspots within fluvially-derived aquifer sediments and overlying soils. The method has been applied to (a) alluvial materials collected at a former uranium mill site near Rifle, Colorado and (b) relatively undisturbed floodplain deposits (soils and sediments) collected along the East River near Crested Butte, Colorado. At Rifle, 16 alluvial samples were taken from 8 sediment cores, and at the East River, 46 soil/sediment samples were collected across and perpendicular to 3 active meanders and an oxbow meander. Regression models using TOC and TOC combined with extractable iron and manganese results were determined to be the best fitting statistical models of microbial DNA (via 16S rRNA gene analysis). Fitting these models to observations in both contaminated and natural floodplain deposits, and their associated alluvial aquifers, demonstrates the broad applicability of the geochemical indicator based approach. PMID:27145490

  16. Reconstruction of the Palaeo-environment of the Alluvial Deposits in the Eastern Free State, South Africa

    Science.gov (United States)

    Evans, M. Y.

    2009-04-01

    Small alluvial fan systems have formed off the hillslopes of the remnant Karoo koppies at Heelbo in the Eastern Free State, South Africa. The landform geometry is a result of complex relationships between climate, lithology, structure and vegetation. This research area, which includes a large mammal mass death site, potentially contains a wealth of palaeo-environmental and specifically palaeoclimatic information. Palaeo-environmental information and proxy records on past climates in southern Africa has traditionally been obtained from a variety of techniques including stable isotope analysis of speleothems, pollen , faunal analyses at archeological sites, animal remains and crater-lake sediments (see references below). However, little information exists in the scientific literature on the use of palaeosols for defining the depositional palaeoenvironments in southern Africa. The aim of this research is to attempt to address the lack of palaeo-environmental information by extracting palaeoclimatic information from the sedimentary processes and the palaeosols at the Heelbo farm that have been extensively exposed through gullying. The sedimentary fans in the area have experienced climatically controlled histories of erosion, sedimentation and pedogenesis. Extreme sedimentation is assumed to have occurred during relatively arid climatic intervals, when decreased vegetation cover provided little surface protection. In contrast pedogenesis occurs during humid intervals when vegetation cover is restored, the land stabilizes and the uppermost gravely sands weather to form soils. A combined approach of both radiocarbon- and luminescence -dating may provide a detailed chronology of these successive hillslope events in order to relate hillslope instability to climatic forcing factors. Preliminary results indicate that at least 3 depositional events are recorded within the large mammal mass death site, which have been confirmed by the radiocarbon dates of 3,610 ±110 in the top

  17. Distribution of rare earth elements in sewage-irrigated soil profiles in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhaozhou; WANG Zhongliang; LI Jun; LI Yong; ZHANG Zhigang; ZHANG Peng

    2012-01-01

    The concentrations of rare earth elements (REEs) in the soil extracts and soil solutions from two different alluvial soil profiles irrigated with sewage were measured using inductively coupled plasma-mass spectrometry.The results showed that the REE concentrations in the soil extracts from soil samples affected by sewage irrigation were much higher than those in virgin soil samples.The REE concentrations in the soil extracts of the rhizophere soil were higher than those of the non-rhizophere soil.The shale-normalized REE patterns in the soil extracts from the upper soil layer affected by sewage irrigation shown middle REE (MREE) enrichment relative to light REE (LREE) and heavy REE (HREE).This result was attributed to the MREE-rich organic colloidal material,REE-HM (humic and fulvic acids) and phosphate-REE complexations.The REE patterns in the soit extracts from deep soil little-affected by sewage irrigation showed HREE enrichment relative to LREE,which might have been caused by the preferential complexation of HREE with carbonate.The normalized La/Yb ratios in the soil extracts increased with the decrease in depth.The sewage irrigation did not affect the total REE contents and REE pattern in the soil profiles.

  18. Controls on matrix flow, preferential flow and deep drainage rates in an alluvial Vertisol.

    Science.gov (United States)

    Arnold, Sven; Larsen, Joshua; Reading, Lucy; Finch, Warren; Bulovic, Nevenka; McIntyre, Neil

    2016-04-01

    Deep drainage is the process that describes water percolating from the land surface to a depth below the root zone where it may contribute to groundwater recharge. Quantitative estimation of deep drainage through Vertisols is challenging, largely due to the unknown relative contributions from: (i) flow through the soil matrix; and (ii) flow along preferential pathways in particular soil cracks, and how to model the transience of the relative contributions. The Condamine River Alluvium, a significant aquifer in semi-arid eastern Australia, is mostly covered by uniform dark cracking clays such as Black and Grey Vertisols. The aim of this study was to identify the environmental conditions (rainfall, antecedent soil moisture, etc) controlling matrix and preferential flow in selected Vertisol profiles at the time scale of individual rainfall events. Field experiments (including 16 probes recording soil moisture at one hour intervals across eight depths between 100 mm and 4000 mm) provide extensive soil moisture data, supplemented by weather station data collected at 15-minute intervals. In addition, laboratory experiments were used to infer the water retention curves. These data were used to (i) derive deep drainage rates using the zero-flux plane method, and (ii) calibrate a soil moisture balance model that represents both matrix and preferential flow. The model was used to estimate the parts of the vertical water flux attributed to soil matrix and preferential flow. High antecedent soil moisture was associated with low fluxes at shallow depths, however at deeper depths both low and high antecedent soil moisture were associated with larger fluxes. Further, both rainfall amount and intensity controlled the interplay between matrix and preferential flow. The results reveal new insights into deep drainage processes in Vertisols and provide the basis for developing a practical approach for deep drainage estimation.

  19. Mapeamento de áreas aluvionares no semiárido brasileiro por meio de dados colaterais e imagens orbitais Mapping alluvial areas in semi-arid region of Brazil through collateral data and satellite images

    Directory of Open Access Journals (Sweden)

    Helio L. Lopes

    2013-07-01

    Full Text Available A região semiárida do Brasil possui grande potencial para armazenamento de água em áreas aluvionares, podendo potencializar a pequena agricultura. Verifica-se a necessidade de uma metodologia para mapeamento dessas áreas, com o objetivo de futuros estudos in loco para implantação de barragens subterrâneas e manejo correto dos solos aluvionares. Neste sentido, objetivou-se a aplicação de imagens Landsat- Mapeador Temático 5 em conjunto com dados colaterais, como a rede de drenagem, mapa de classes de solo e mapa de relevo para auxiliar na classificação de terraços aluviais. Teve-se, como área de estudo, a bacia do Rio Pajeú, no sertão do estado de Pernambuco. Buscou-se também, por meio de dados SRTM (Shuttle Radar Topography Mission, a avaliação topográfica das áreas classificadas. Verifica-se que a utilização única de dados orbitais traz classificação incongruente mas com a inserção de dados colaterais é possível obter melhores resultados na classificação. A rede de drenagem é fundamental no mascaramento de classificações espúrias. Quando procede à análise topográfica por meio de dados do SRTM das áreas classificadas como terraços aluvionares, observa-se a inconsistência desses dados.The semi-arid region of Brazil has great potential for storing water in alluvial areas, and may give support to small-scale family farming. There is a need to establish a methodology for mapping these areas with the objective of future studies to implement underground dams and suitable management of the soils that occur on alluvial terraces. In this way, the aim of this study was to apply Landsat-Thematic Mapper images together with collateral data such as the drainage network, map of soil classes and elevation data to assist in the classification of alluvial terraces. The study area was Pajeú River basin located in the 'Caatinga' ecosystem of the Pernambuco state. Topographic assessment of the alluvial areas was done by

  20. Soils - NRCS Web Soil Survey

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Web Soil Survey (WSS) provides soil data and information produced by the National Cooperative Soil Survey. It is operated by the USDA Natural Resources Conservation...

  1. Fractionation and solubility of cadmium in paddy soils amended with porous hydrated calcium silicate

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-lan; Saigusa Masaihiko

    2007-01-01

    Previous studies have shown that porous hydrated calcium silicate(PS)is very effective in decreasing cadmium(Cd)content in brown rice.However,it is unclear whether me PS influences cadmium transformation in soil.The present study examined the effect of PS on pH,cadmium transformation and cadmium solubility in Andosol and Alluvial soil,and also compared its effects with CaCO3,acidic porous hydrated calcium silicate(APS)and silica gel.Soil cadmium was operationally fractionationed into exchangeable(Exch),bound to carbonates(Carb).bound to iron and manganese oxides(FeMnOx),bound to organic matters(OM)and residual(Res)fraction.ApplicatiOn of PS and CaCO3 at hig rates enhanced soil pH,while APS and silica gel did not obviously change soil pH.PS and CaCO3 also increased the FeMnOx-Cd in Andosol and Carb-Cd in Alluvial soil,thus reducing the Exch-Cd in me tested soils.However,PS was less effecfive than CaCO3 at the same application rate.Cadmium fractions in the two soils were not changed by the treatments of APS and silica gel.There were no obvious differences in the solubility of cadmium in soils treated with PS,APS,silica gel and CaCO3 except Andosol treated 2.0%CaCO3 at the same pH of soil-CaCl2 suspensions.These findings suggested that the decrease of cadmium availability in soil was mainly attributed to the increase of soil pH caused by PS.

  2. Evaluating the Risks of Surface Spills Associated with Hydraulic Fracturing Activities to Groundwater Resources: a Modeling Study in the South Platte Alluvial Aquifer

    Science.gov (United States)

    Kanno, C.; McLaughlin, M.; Blotevogel, J.; Benson, D. A.; Borch, T.; McCray, J. E.

    2015-12-01

    Hydraulic fracturing has revolutionized the U.S.'s energy portfolio by making shale reservoirs productive and commercially viable. However, the public is concerned that the chemical constituents in hydraulic fracturing fluid, produced water, or natural gas itself could potentially impact groundwater or adjacent streams. Here, we conduct fate and transport simulations of surface spills, the most likely contamination pathway to occur during oil and gas production operations, to evaluate whether or not these spills pose risks to groundwater quality. We focus on the South Platte Alluvial Aquifer, which is located in the greater Denver metro area and overlaps a zone of high-density oil and gas development. The purpose of this work is to assess the mobility and persistence of chemical contaminants (e.g. biocides, friction reducers, surfactants, hydrocarbons, etc.) —based on sorption to soil, degradation potential, co-contaminant interactions, and spill conditions—and to understand the site characteristics and hydrologic conditions that would make a particular location prone to groundwater quality degradation in the event of an accidental release. We propose a coupled analytical-numerical approach that could be duplicated by environmental consultants. Results suggest that risk of groundwater pollution, based on predicted concentration at the groundwater table, is low in most areas of the South Platte system for the contaminants investigated under common spill conditions. However, substantial risk may exist in certain areas where the groundwater table is shallow. In addition, transport of certain contaminants is influenced by interactions with other constituents in produced or stimulation fluids. By helping to identify locations in the Front Range of Colorado that are at low or high risk for groundwater contamination due to a surface spill, it is our hope that this work will aid in improving prevention, mitigation, and remediation practices so that decision-makers can

  3. Alluvial-eolian interaction in a Cambrian rift margin: the Pedra das Torrinhas and Pedra Pintada formations (Guaritas Group, RS

    Directory of Open Access Journals (Sweden)

    André Marconato

    2009-12-01

    Full Text Available This work presents a study of selected outcrops from the Pedra das Torrinhas Formation of the Guaritas Group (Cambrian, Camaquã Basin, near the basin bordering Encantadas Fault Zone. The studied succession includes alluvial fan deposits that pass laterally into eolian deposits. Sedimentary facies and architectural element analysis were performed, followed by sedimentary petrography and microscopic porosity analysis, aiming to characterize the porosity of the deposits and its spatial distribution. The main objective was to contribute to a better understanding of the porosity spatial distribution in depositional systems characterized by the interaction between alluvial and eolian processes, with special reference to deposits formed prior to the development of terrestrial plants. Porosity values are related to depositional processes, with higher porosities associated to eolian dune deposits (mean of 8.4%, and lower porosity related to interdunes (mean of 3.4% and alluvial fans (mean of 4.3%. Architectural elements analysis revealed the spatial relationships of these deposits, a response to the interplay of the eolian and alluvial processes. The integration of porosity data reveals that the interaction of alluvial and eolian processes results in heterogeneous distribution of porosity at the facies association scale. Eolian reworking of alluvial facies increases porosity whereas sheet-flood and other alluvial processes in the interdune areas reduce porosity.O presente trabalho consiste no estudo de afloramentos da Formação Pedra das Torrinhas do Grupo Guaritas (Cambriano, Bacia Camaquã, próximo à Zona de Falha das Encantadas. As sucessões estudadas incluem depósitos de leques aluviais que passam lateralmente para depósitos eólicos. Foram realizadas análises de fácies e de elementos arquiteturais, seguidos de petrografia sedimentar e análise microscópica de porosidade, com o objetivo de caracterizar a porosidade da unidade e sua

  4. Study on the growth and tolerance ability of Polygonum hydropiper L. and Hymenachne acutigluma (Steud.) Gilliland on Pb and Cd polluted soil

    OpenAIRE

    Chu, Thi Thu Ha

    2015-01-01

    Two plant species including Polygonum hydropiper L. and Hymenachne acutigluma (Steud.) Gilliland were investigated in their resistance to lead (Pb) and cadmium (Cd) pollution in the soil. Lead-contaminated soil samples were collected from the lead recycling village Dong Mai, Chi Dao commune, Van Lam district, Hung Yen province, Vietnam that had Pb level up to 192,185 mg.kg-1, dry weight (DW). Cadmium-contaminated soil samples were due to supplement of CdCl2.21/2H2O to alluvial soil. Results s...

  5. Fluid/melt inclusions in alluvial Northeast Siberian diamonds: new approach on diamond formation.

    Science.gov (United States)

    Logvinova, Alla M.; Wirth, Richard; Sobolev, Nikolai V.

    2010-05-01

    The origin of alluvial Northeast Siberian diamonds is still a subject of controversy. Fluid/melt inclusions in diamonds are the deepest available samples of mantle fluids and provide the unique information on the medium in which diamonds have grown. These inclusions carry high-density fluids (HDFs), the compositional variability is in the range of hydrous-silicic, carbonatitic (high-Mg and low-Mg) and saline end-members. Previous studies of the bulk composition and internal morphology of microinclusions in alluvial Northeast Siberian diamonds suggested that they contain fluids, but distribution and structure of their constitutional phases could not be determined. We investigated two populations of diamonds from Northeast Siberian Platform placers (Ebelyakh area) using TEM, FTIR, EPMA methods: (I) rounded single-crystals (dodecahedrons, octahedrons and irregular stones with a black central zone rich in microinclusions. Some of them frequently exhibit growth twinning; (II) rounded dark crystals, related to variety V according to the classification by Orlov (1977). This group of stones has their own typical features: dark color due to abundant black microinclusions and high dislocation density; mosaic-block internal structure; very light carbon isotopic composition; the high degree of nitrogen aggregation and nearly total absence of mineral inclusions. Diamonds of the first population are characterized by two types of fluid/melt nanoinclusions:1) multi-phase high- Mg assemblages, which include solid phases (magnesite, dolomite, clinohumite, Fe-spinel, graphite) and fluid bubbles; 2) oriented sulfide melt nanoinclusions in association with halides (KCl, NaCl), high-Si mica and fluid bubbles. All of them ranging between 5 and 200 nm in diameter are reflecting the diamond habit. Sulfides are homogeneous in composition. The Ni/(Ni+Fe) ratio of the inclusions is 0.037±0.04. Still closed fluid bubbles were identified in TEM studies as changing absorption contrast due to

  6. Biogeochemistry at a wetland sediment-alluvial aquifer interface in a landfill leachate plume

    Science.gov (United States)

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

    2009-01-01

    The biogeochemistry at the interface between sediments in a seasonally ponded wetland (slough) and an alluvial aquifer contaminated with landfill leachate was investigated to evaluate factors that can effect natural attenuation of landfill leachate contaminants in areas of groundwater/surface-water interaction. The biogeochemistry at the wetland-alluvial aquifer interface differed greatly between dry and wet conditions. During dry conditions (low water table), vertically upward discharge was focused at the center of the slough from the fringe of a landfill-derived ammonium plume in the underlying aquifer, resulting in transport of relatively low concentrations of ammonium to the slough sediments with dilution and dispersion as the primary attenuation mechanism. In contrast, during wet conditions (high water table), leachate-contaminated groundwater discharged upward near the upgradient slough bank, where ammonium concentrations in the aquifer where high. Relatively high concentrations of ammonium and other leachate constituents also were transported laterally through the slough porewater to the downgradient bank in wet conditions. Concentrations of the leachate-associated constituents chloride, ammonium, non-volatile dissolved organic carbon, alkalinity, and ferrous iron more than doubled in the slough porewater on the upgradient bank during wet conditions. Chloride, non-volatile dissolved organic carbon (DOC), and bicarbonate acted conservatively during lateral transport in the aquifer and slough porewater, whereas ammonium and potassium were strongly attenuated. Nitrogen isotope variations in ammonium and the distribution of ammonium compared to other cations indicated that sorption was the primary attenuation mechanism for ammonium during lateral transport in the aquifer and the slough porewater. Ammonium attenuation was less efficient, however, in the slough porewater than in the aquifer and possibly occurred by a different sorption mechanism. A

  7. The utility of gravity and water-level monitoring at alluvial aquifer wells in southern Arizona

    Science.gov (United States)

    Pool, D.R.

    2008-01-01

    Coincident monitoring of gravity and water levels at 39 wells in southern Arizona indicate that water-level change might not be a reliable indicator of aquifer-storage change for alluvial aquifer systems. One reason is that water levels in wells that are screened across single or multiple aquifers might not represent the hydraulic head and storage change in a local unconfined aquifer. Gravity estimates of aquifer-storage change can be approximated as a one-dimensional feature except near some withdrawal wells and recharge sources. The aquifer storage coefficient is estimated by the linear regression slope of storage change (estimated using gravity methods) and water-level change. Nonaquifer storage change that does not percolate to the aquifer can be significant, greater than 3 ??Gal, when water is held in the root zone during brief periods following extreme rates of precipitation. Monitor-ing of storage change using gravity methods at wells also can improve understanding of local hydrogeologic conditions. In the study area, confined aquifer conditions are likely at three wells where large water-level variations were accompanied by little gravity change. Unconfined conditions were indicated at 15 wells where significant water-level and gravity change were positively linearly correlated. Good positive linear correlations resulted in extremely large specific-yield values, greater than 0.35, at seven wells where it is likely that significant ephemeral streamflow infiltration resulted in unsaturated storage change. Poor or negative linear correlations indicate the occurrence of confined, multiple, or perched aquifers. Monitoring of a multiple compressible aquifer system at one well resulted in negative correlation of rising water levels and subsidence-corrected gravity change, which suggests that water-level trends at the well are not a good indicatior of overall storage change. ?? 2008 Society of Exploration Geophysicists. All rights reserved.

  8. Complementing airborne laser bathymetry with UAV-based lidar for capturing alluvial landscapes

    Science.gov (United States)

    Mandlburger, Gottfried; Pfennigbauer, Martin; Riegl, Ursula; Haring, Alexander; Wieser, Martin; Glira, Philipp; Winiwarter, Lukas

    2015-10-01

    In this paper we report on a flight experiment employing airborne laser bathymetry (ALB) and unmanned aerial vehicle (UAV) based laser scanning (ULS) for capturing very high resolution topography of shallow water areas and the surrounding littoral zone at the pre-alpine Pielach River in Austria. The aim of the research is to assess how information gained from non-bathymetric, ultra-high resolution ULS can support the ALB data. We focus first on the characterization of the water surface of a lowland river and provide validation results using the data of a topographic airborne laser scanning (ALS) sensor and a low flying ULS system. By repeat ULS survey of a the meandering river reach we are able to quantify short-term water level changes due to surface waves in high resolution. Based on a hydrodynamic-numerical (HN) model we assess the accuracy of the water surface derived from a water penetrating ALB sensor. In the second part of the paper we investigate the ability of ALB, ALS, and ULS to describe the complex topography and vegetation structure of the alluvial area. This is carried out by comparing the Digital Terrain Models (DTM) derived from different sensor configurations. Finally we demonstrate the potential of ULS for estimating single tree positions and stem diameters for detailed floodplain roughness characterization in HN simulations. The key findings are: (i) NIR scan data from ALS or ULS provide more precise water level height estimates (no bias, 1σ: 2 cm) compared to ALB (bias: 3 cm, 1σ: 4 cm), (ii) within the studied reach short-term water level dynamics irrelevant for ALB data acquisition considering a 60 cm footprint diameter, and (iii) stem diameters can be estimated based on ULS point clouds but not from ALS and ALB.

  9. Plucking in Mixed Alluvial-Bedrock Rivers: The Incipient Motion Problem

    Science.gov (United States)

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

    2015-12-01

    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.

  10. Land use effects in groundwater composition of an alluvial aquifer (Trussu River, Brazil) by multivariate techniques.

    Science.gov (United States)

    de Andrade, Eunice Maia; Palácio, Helba Araújo Queiroz; Souza, Ivam Holanda; de Oliveira Leão, Raimundo Alípio; Guerreiro, Maria João

    2008-02-01

    Multivariate statistical techniques, cluster analysis (CA) and factor analysis/principal component analysis (FA/PCA), were applied to analyze the similarities or dissimilarities among the sampling sites to identify spatial and temporal variations in water quality and sources of contamination (natural and anthropogenic). The aquifer under study is supplied by the Trussu River, which has a general direction from west to east, within Iguatu County, Ceará, Brazil. Groundwater samples were collected in four shallow wells, located at the Trussu River alluvial, from October 2002 to February 2004. The samples were analyzed for 13 parameters: pH, electrical conductivity (EC), Na, Ca, Mg, K, Cl, HCO(3), PO(4), NH(4)-N, NO(3)-N, SO(4), and sodium adsorption ratio (SAR). Two zones were very well differentiated based on cluster analysis results, and implied a relation to geographic position and time variation. One zone called UL-upland region-corresponds to upland of studied area, used mainly for irrigation and livestock activities. The other zone called DL-downland region-corresponds to the region downstream and is occupied by human settlements. These results may be used to reduce the number of samples analyzed both in space and time, without too much loss of information. Three major independent factors that define water quality in the UL region and four in DL region were identified in the PCA. At both regions, rotated component (RC) loadings identified that the variables responsible for water quality composition are mainly related to soluble salts variables (natural process) and nutrients (high loads of NO(3)-N, NH(4)-N), expressing anthropogenic activities. RC also revealed that hydrochemical processes were the major factors responsible for water quality. PMID:18062960

  11. Geochemistry of carbonate cements in surficial alluvial conglomerates and their paleoclimatic implications, Sultanate of Oman

    Energy Technology Data Exchange (ETDEWEB)

    Burns, S.J.; Matter, A. [Univ. Bern (Switzerland). Geologisches Inst.

    1995-01-02

    Early diagenetic carbonate cements are a common feature of Quaternary alluvial conglomerates in Oman. Cements are formed in the vadose and, more commonly, phreatic zones from near-surface groundwaters. In drainage areas underlain by the Semail Ophiolite, groundwaters have Mg{sup 2+}/Ca{sup 2+} ratios greater than two, and cements are often dolomite or high-magnesium calcite in addition to low-magnesium calcite. In drainage areas underlain by limestone, groundwaters have Mg{sup 2+}/Ca{sup 2+} ratios of around one or less and cement mineralogy is nearly always low-magnesium calcite. The oxygen and carbon stable isotopic ratios of the cements vary widely, from {minus}10.6{per_thousand} to +3.0{per_thousand} PDB and from {minus}10.0{per_thousand} to +0.7{per_thousand} PDB, respectively. Cement {delta}{sup 18}O values principally reflect variation in rainfall {delta}{sup 18}O over a time scale of several thousand years. Rainfall and cement {delta}{sup 18}O values probably are inversely correlated with the amount of rainfall, which is related to the frequency and intensity of the Indian Ocean monsoon. Thus, cement {delta}{sup 18}O is potentially a proxy indicator of relative rainfall and monsoon activity. For each of three sampling areas, {delta}{sup 13}C is positively correlated to {delta}{sup 18}O. Cement {delta}{sup 13}C values are also related to rainfall amount because rainfall controls the plant population. Greater plant respiration of isotopically depleted CO{sub 2} to shallow groundwaters and burial of organic material in conglomerate deposits results in lower cement {delta}{sup 13}C values compared to periods of lesser plant activity.

  12. Global- and local-scale characterisation of bed surface structure in coarse-grained alluvial rivers

    Science.gov (United States)

    Powell, Mark; Ockelford, Annie; Nguyen, Thao; Wood, Jo; Rice, Steve; Reid, Ian; Tate, Nick

    2013-04-01

    It is widely recognised that adjustments in bed surface grain size (texture) and grain arrangement (structure) exert significant controls on the stability of coarse-grained alluvial rivers. Modifications to bed surface texture and structure occur during active sediment transport and are mediated by the process of mobile armouring which concentrates coarser-than-average particles on the surface and organises them into a variety of grain- and bedform-scale configurations. Textural aspects of surface armouring are well understood to the extent that sediment transport models can be used to predict the size distribution of armours that develop under different sediment supply regimes and shear stresses. Research has also found that the adjustment of bed surface grain size is often patchy and that the development of finer-grained and coarser-grained areas of the bed has important implications for both the rate and grain size of transported sediment. The structural aspects of stream-bed armouring, however, are less well understood, largely because of the difficulty of recognising and characterising bedforms and bed-structures that have dimensions similar to their constituent particles. Moreover, bed structure is generally parameterised using global scale descriptors of the bed surface such that information on the spatial heterogeneity of the structure is lost. The aim of this poster is to characterise the structural characteristics of water-worked river gravels, paying particular attention to quantifying the spatial heterogeneity of those characteristics using local scale descriptors. Results reported from a number of flume experiments designed to simulate the spatio-temporal evolution of bed configurations (surface texture and structure) as the system adjusts to a condition of equilibrium transport are used to evaluate the spatial variability of bed surface structure and explore its significance for modelling sediment transport rates in gravel-bed rivers. Keywords: bed

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

    Science.gov (United States)

    Ertekin, Can; Sedat Çetiner, Ziya

    2015-04-01

    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

  14. Uranium-series comminution ages of continental sediments: Case study of a Pleistocene alluvial fan

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Victoria E.; DePaolo, Donald J.; Christensen, John N.

    2010-04-30

    Obtaining quantitative information about the timescales associated with sediment transport, storage, and deposition in continental settings is important but challenging. The uranium-series comminution age method potentially provides a universal approach for direct dating of Quaternary detrital sediments, and can also provide estimates of the sediment transport and storage timescales. (The word"comminution" means"to reduce to powder," reflecting the start of the comminution age clock as reduction of lithic parent material below a critical grain size threshold of ~;;50 mu m.) To test the comminution age method as a means to date continental sediments, we applied the method to drill-core samples of the glacially-derived Kings River Fan alluvial deposits in central California. Sediments from the 45 m core have independently-estimated depositional ages of up to ~;;800 ka, based on paleomagnetism and correlations to nearby dated sediments. We characterized sequentially-leached core samples (both bulk sediment and grain size separates) for U, Nd, and Sr isotopes, grain size, surface texture, and mineralogy. In accordance with the comminution age model, where 234U is partially lost from small sediment grains due to alpha recoil, we found that (234U/238U) activity ratios generally decrease with age, depth, and specific surface area, with depletions of up to 9percent relative to radioactive equilibrium. The resulting calculated comminution ages are reasonable, although they do not exactly match age estimates from previous studies and also depend on assumptions about 234U loss rates. The results indicate that the method may be a significant addition to the sparse set of available tools for dating detrital continental sediments, following further refinement. Improving the accuracy of the method requires more advanced models or measurements for both the recoil loss factor fa and weathering effects. We discuss several independent methods for obtaining fa on individual samples

  15. Orbital forcing in the early Miocene alluvial sediments of the western Ebro Basin, Northeast Spain

    Science.gov (United States)

    Garces, M.; Larrasoaña, J. C.; Muñoz, A.; Margalef, O.; Murelaga, X.

    2009-04-01

    Paleoclimatic reconstructions from terrestrial records are crucial to assess the regional variability of past climates. Despite the apparent direct connection between continental sedimentary environments and climate, interpreting the climatic signature in ancient non-marine sedimentary sequences is often overprinted by source-area related signals. In this regard, foreland basins appear as non-ideal targets as tectonically-driven subsidence and uplift play a major control on the distribution and evolution of sedimentary environments and facies. Foreland basins, however, often yield among the thickest and most continuous stratigraphic records available on continents. The Ebro Basin (north-eastern Spain) is of particular interest among the circum-mediterranean alpine foreland basins because it evolved into a land-locked closed basin since the late Eocene, leading to the accumulation of an exceptionally thick (>5500 m) and continuous sequence of alluvial-lacustrine sediments over a period of about 25 Myr. In this paper we present a detailed cyclostratigraphic study of a 115 m thick section in the Bardenas Reales de Navarra region (western Ebro Basin) in order to test orbital forcing in the Milankovitch frequency band. The study section corresponds to the distal alluvial-playa mud flats which developed in the central sector of the western Ebro Basin, with sediments sourced from both the Pyrenean and Iberian Ranges. Sediments consist of brown-red alluvial clay packages containing minor fine-grained laminated sandstones sheet-beds and channels, grey marls and thin bedded lacustrine limestones arranged in 10 to 20 m thick fining-upwards sequences. Red clayed intervals contain abundant nodular gypsum interpreted as representing a phase of arid and low lake level conditions, while grey marls and limestones indicate wetter intervals recording the expansion of the inner shallow lakes. A magnetostratigraphy-based chronology indicates that the Peñarroya section represents a

  16. Modeling Soil-Landscape Relations in the Sonoran Desert, Arizona, USA

    Science.gov (United States)

    Regmi, N. R.; Rasmussen, C.

    2015-12-01

    Digital soil mapping (DSM) techniques that integrate remotely sensed surface topography and reflectance, and map soil-landscape associations have the potential in improve understanding of critical zone evolution and landscape processes. The goal of this study was to understand the soil-geomorphic evolution of Quaternary alluvial and eolian deposits in the Sonoran Desert using a data-driven DSM technique and mapping of soil-landscape relationships. An iterative principal component analysis (iPCA) data reduction routine was developed and implemented for a set of LiDAR elevation- and Landsat ETM+-derived environmental covariates that characterize soil-landscape variability. Principal components that explain more than 95% of the soil-landscape variability were then integrated and classified based on an ISODATA (Iterative Self-Organizing Data) unsupervised technique. The classified map was then segmented based on a region growing algorithm and multi-scale maps of soil-landscape relations were developed, which then compared with maps of major arid-region landforms that can be identified on aerial photographs and satellite images by their distinguishing tone and texture, and in the field by their distinguishing surface and sub-surface soil physical, chemical and biological properties. The approach identified and mapped the soil-landscape variability of alluvial and eolian landscapes, and illustrated the applicability of coupling covariate selection and integration by iPCA, ISODATA classifications of integrated layers, and image segmentation for effective spatial prediction of soil-landscape characteristics. The approach developed here is data-driven, cost- and time-effective, applicable for multi-scale mapping, allows incorporation of wide variety of covariates, and provides accurate quantitative prediction of wide range of soil-landscape attributes that are necessary for hydrologic models, land and ecosystem management decisions, and hazard assessment.

  17. Leaf anatomy of Copaifera langsdorffii Desf. (Leguminosae: ecological interpretations based on different soil conditions in the Cerrado

    Directory of Open Access Journals (Sweden)

    João Carlos Ferreira de Melo Júnior

    2012-11-01

    Full Text Available Copaifera langsdorffii Desf. (Caesalpinioideae, Leguminosae is a tree known as copaíba that is widely distributed in Brazil. The present paper discusses, from an ecological perspective, leaf structural changes in populations of copaíba found growing in three different substrates in the Cerrado: alluvial neosoil on riverbanks, sandstone and red latosol in savanna. Qualitative and quantitative leaf traits were observed from permanent histological preparations. Statistically significant differences were observed in all of the ecological parameters analyzed, such as specific leaf area, tissue thickness and stomatal density. A higher proportion of scleromorphic features was found in plants growing on the sandstone and alluvial neosoil, although the latosol was also low in exchangeable bases. The structural changes observed were the result of the combination of soil factors, water, microclimate and plant/herbivore interaction related to each substrate; it was clear that soil nutrients had more influence on these changes than water availability.

  18. Water availability and use pilot; methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona

    Science.gov (United States)

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

    2011-01-01

    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

  19. Radon migration in the soils of the Irno Valley (Southern Italy inferred from radioactive disequilibrium

    Directory of Open Access Journals (Sweden)

    P. Gasparini

    1995-06-01

    Full Text Available Radon migration along vertical profiles in the soils of Irno River alluvial Valley (Southern Italy was studied using radioactive disequilibrium between 226 Ra and 210 Pb. Fractional Radon loss, migration length, diffusion and emanation coefficient and Radon flux density were determined. Our results are in agreement with a migra- tion model by simple diffusion. The migration parameters are within typical values, except the Radon flux density, which is about one order of magnitude higher than the values reported in literature. The values of fractional Radon loss are sensitive to changes in the physical properties of the soil.

  20. Hydrologic characterization of desert soils with varying degrees of pedogenesis: 1. field experiments evaluating plant-relevant soil water behavior

    Science.gov (United States)

    Nimmo, J.R.; Perkins, K.S.; Schmidt, K.M.; Miller, D.M.; Stock, J.D.; Singha, K.

    2009-01-01

    To assess the eff ect of pedogenesis on the soil moisture dynamics infl uencing the character and quality of ecological habitat, we conducted infi ltration and redistribution experiments on three alluvial deposits in the Mojave National Preserve: (i) recently deposited active wash sediments, (ii) a soil of early Holocene age, and (iii) a highly developed soil of late Pleistocene age. At each, we ponded water in a 1-m-diameter infi ltration ring for 2.3 h and monitored soil water content and matric pressure during and atier infi ltration, using probes and electrical resistivity imaging (ERI). Infi ltration and downward fl ow rates were greater in younger material, favoring deep-rooted species. Deep-rooted species tend to colonize the margins of washes, where they are unaff ected by sediment transport that inhibits colonization. The ERI results support important generalizations, for example that shallower than 0.5 m, infi ltrated water persists longer in highly developed soil, favoring shallow-rooted species. Soil moisture data for the two youngest soils suggested that saturation overshoot, which may have signifi cant but unexplored hydroecologic and pedogenic eff ects, occurred at the horizontally advancing weting front. Spatial heterogeneity of soil properties generally increased with pedogenic development. Evidence suggested that some early-stage developmental processes may promote uniformity; the intermediate- age soil appeared to have the least heterogeneity in terms of textural variation with depth, and also the least anisotropy. Lateral heterogeneity was pronounced in older soil, having a multitude of eff ects on the distribution and retention of soil water, and may facilitate certain water-conserving strategies of plants over what would be possible in a laterally homogeneous soil. ?? Soil Science Society of America.

  1. DECOMPOSITION OF BT COTTON AND NON BT COTTON RESIDUES UNDER VARIED SOIL TYPES

    Directory of Open Access Journals (Sweden)

    Sujata Kumari

    2014-04-01

    Full Text Available Use of the insecticidal cry proteins from the bacterium, Bacillus thuringiensis (Bt in cotton has raised a number of concerns, including the ecological impact on soil ecosystems.Greenhouse study was conducted during the 2011 wet season (March to August at the Institute of Agricultural Sciences of Banaras Hindu University. It was carried out on three different soil orders that includedentisol, inceptisol and alfisol. Bt cotton (var.NCS-138 and its non-transgenic isoline (var.NCS-138 were grown until maturity. A no crop pot was maintained for all the three soil orders. The highest rate of decomposition was found in alluvial soil compared to black and red soils in 50 days after incorporation (DAI. Thereafter the rate of decomposition was slowed downby100 DAI and the constant rate of decomposition was found in 150 DAI. The rate of decomposition was higher in non Bt than Bt crop residues.

  2. Flood susceptibility assessment in a highly urbanized alluvial fan: the case study of Sala Consilina (southern Italy

    Directory of Open Access Journals (Sweden)

    N. Santangelo

    2011-10-01

    Full Text Available This paper deals with the risk assessment to alluvial fan flooding at the piedmont zone of carbonate massifs of the southern Apennines chain (southern Italy. These areas are prime spots for urban development and are generally considered to be safer than the valley floors. As a result, villages and towns have been built on alluvial fans which, during intense storms, may be affected by flooding and/or debris flow processes.

    The study area is located at the foothills of the Maddalena mountains, an elongated NW-SE trending ridge which bounds to the east the wide intermontane basin of Vallo di Diano. The area comprises a wide detrital talus (bajada made up by coalescent alluvial fans, ranging in age from the Middle Pleistocene to the Holocene. Historical analysis was carried out to ascertain the state of activity of the fans and to identify and map the zones most hit by past flooding. According to the information gathered, the Sala Consilina fans would appear prone to debris flows; in the past these processes have produced extensive damage and loss of life in the urban area. The watershed basins feeding the fans have very low response times and may produce debris flow events with high magnitudes. Taking into account the historical damage, the fan surface morphology, and the present urban development (street orientation and hydraulic network, the piedmont area was zoned and various susceptibility classes were detected. These results may represent a useful tool for studies aiming at territorial hazard mapping and civil protection interventions.

  3. Delineation of alluvial fans from Digital Elevation Models with a GIS algorithm for the geomorphological mapping of the Earth and Mars

    Science.gov (United States)

    Norini, Gianluca; Zuluaga, Maria Clara; Ortiz, Iris Jill; Aquino, Dakila T.; Lagmay, Alfredo Mahar F.

    2016-11-01

    Alluvial fans are prominent depositional geomorphic features present in nearly all global climates on Earth, and also found on Mars. In this study, we present a Geographic Information System (GIS) algorithm designed for the semi-automated detection of alluvial fans that are connected to their contributing upstream drainage network, from the analysis of Digital Elevation Models (DEMs). Through a combination of spatial analysis procedures, the GIS algorithm generates maps of alluvial fans and their upstream source drainage and watersheds. Tests of the algorithm in areas with well-known alluvial fans indicate that this new GIS procedure is capable of high-accuracy mapping of the fan apexes and correct delineation of fan deposits, in both arid and humid climates. Possible future applications of the GIS algorithm presented in this study include the systematic survey of alluvial fans at the local, regional and planetary scales, important for geologic hazard assessment, studies on the evolution of climate, analysis of continental sedimentary environments, understanding of the interplay between the endogenous dynamics and exogenous processes, and the evaluation of natural resources.

  4. Channel and landscape dynamics in the alluvial forest mosaic of the Carmanah River valley, British Columbia, Canada

    Science.gov (United States)

    Little, Patrick J.; Richardson, John S.; Alila, Younes

    2013-11-01

    The highly diverse shifting-mosaic of forest patches of an alluvial forest within the Carmanah River valley on the west coast of Vancouver Island, British Columbia was studied to examine the hydrogeomorphic disturbance regime that structures it. We used a landscape-scale analysis to quantify historical channel migrations and changes in the extent of specific forest types. This GIS-based analysis using a 70-year aerial photographic record was complemented by field-based research. Thirty-eight plots containing 4509 trees were sampled for forest structure, age, and elevation above the contemporary channel. These data, including a vegetation chronosequence spanning over 500 years, were used to examine channel and landscape dynamics. Our findings support a general conceptual model that describes cycles of patch development and destruction in unconfined alluvial forests of the Pacific Coastal Ecoregion. Over the past century, Carmanah River has eroded nearly 30% of the alluvial forest in this study area, and approximately 65% over the past 500 years. At least 80% of the 2007 channel was forested area within the past 70 years. Younger landforms were disturbed more frequently than mature forest patches, which suggest that as biogeomorphic succession progresses the likelihood of future disturbance decreases. Estimated half lives of landforms ranged from 24 years for pioneer bars to over 1500 years for old growth terraces. Years of regional high magnitude floods resulted in a net loss of floodplain forest area indicating that disturbance was climate driven in this pluvial watershed, whereby rain events result in flood disturbance that converted forests to channel. These events initiate a subsequent course of vegetation succession and geomorphic development, and often result in the deposition of large wood that modifies the channel environment and contributes to channel avulsion and further hydrogeomorphic disturbance. The composition of the landscape is a reflection of the

  5. The significance of avulsion phenomena in the alluvial filling configuration of a mountain stream: Venero Claro (Central Spain)

    Science.gov (United States)

    Ruiz-Villanueva, V.; Díez-Herrero, A.; Bodoque, J. M.; Fernández-García, P.; Ballesteros, J. A.

    2009-04-01

    In the dynamics and evolution of large river floodplains, alluvial fans and debris cones, avulsion phenomena have been considered very important. However, traditionally, in mountain streams, avulsion phenomena have been underestimated because they are not very frequent, and usually they are restricted to little chute cut-off. Nevertheless, there are mountainous areas where the valley bottom gets wider, and the alluvial filling works like an elongated debris cone. The Cabrera Stream in the Venero Claro reach (Spanish Central System) is one of these special areas. In this case, avulsion phenomena took place triggered by flash floods, and they were usually associated with hyperconcentrated flows, which exceeded the upper level of levees and banks, redefining the sedimentary architecture of the alluvial filling. In this study, an analysis of geomorphologic and sedymentological evolution of the alluvial filling in Venero Claro have been carried out. On this way, cartography made from the 19th Century until ninety ages were compared, and a stereoscopic analysis of aerial photographs and digital ortoimages were applied. Furthermore, the sedimentary filling was studied applying classic sedimentological techniques, such as a description and interpretation of sedimentary structures and facies analysis at field. As a result of the geomorphologic evolution analysis, a straightforward evolution model is proposed. This model enhances the relevant importance of the avulsion phenomena in the geomorphologic configuration of the Cabrera Stream in the Venero Claro reach. From the river pattern point of view, the avulsion phenomena originate capture processes in the main stream and its tributaries. As a result of these processes, the drainage network pattern changes successively from dendritic to sub-parallel. On other hand, from the sedimentologic point of view, the stratigraphy is composed of channel facies (debris flow facies and fluvial-torrential gravelbars) and back

  6. Predicting changes in hydrologic retention in an evolving semi-arid alluvial stream

    Science.gov (United States)

    Harvey, J.W.; Conklin, M.H.; Koelsch, R.S.

    2003-01-01

    Hydrologic retention of solutes in hyporheic zones or other slowly moving waters of natural channels is thought to be a significant control on biogeochemical cycling and ecology of streams. To learn more about factors affecting hydrologic retention, we repeated stream-tracer injections for 5 years in a semi-arid alluvial stream (Pinal Creek, Ariz.) during a period when streamflow was decreasing, channel width increasing, and coverage of aquatic macrophytes expanding. Average stream velocity at Pinal Creek decreased from 0.8 to 0.2 m/s, average stream depth decreased from 0.09 to 0.04 m, and average channel width expanded from 3 to 13 m. Modeling of tracer experiments indicated that the hydrologic retention factor (Rh), a measure of the average time that solute spends in storage per unit length of downstream transport, increased from 0.02 to 8 s/m. At the same time the ratio of cross-sectional area of storage zones to main channel cross-sectional area (As/A) increased from 0.2 to 0.8 m2/m2, and average water residence time in storage zones (ts) increased from 5 to 24 min. Compared with published data from four other streams in the US, Pinal Creek experienced the greatest change in hydrologic retention for a given change in streamflow. The other streams differed from Pinal Creek in that they experienced a change in streamflow between tracer experiments without substantial geomorphic or vegetative adjustments. As a result, a regression of hydrologic retention on streamflow developed for the other streams underpredicted the measured increases in hydrologic retention at Pinal Creek. The increase in hydrologic retention at Pinal Creek was more accurately predicted when measurements of the Darcy-Weisbach friction factor were used (either alone or in addition to streamflow) as a predictor variable. We conclude that relatively simple measurements of channel friction are useful for predicting the response of hydrologic retention in streams to major adjustments in channel

  7. S2-Project: Near-fault earthquake ground motion simulation in the Sulmona alluvial basin

    Science.gov (United States)

    Faccioli, E.; Stupazzini, M.; Galadini, F.; Gori, S.

    2008-12-01

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

  8. Modeling of Reactive Transport of Nitrate in a Heterogeneous Alluvial Fan Aquifer, San Joaquin Valley, California

    Science.gov (United States)

    Green, C. T.; Phillips, S. P.

    2005-12-01

    Fate of nitrate in an alluvial fan aquifer in the San Joaquin Valley, California, was investigated with combined laboratory analyses, field measurements, geostatistics, and flow and reactive transport modeling. In the summer of 2003, groundwater wells and lysimeters were installed along a 1-km transect extending upgradient from the Merced River through an unfarmed riparian zone, a corn field, and an orchard. Groundwater levels have been monitored continuously. Saturated and unsaturated pore waters were analyzed quarterly for nutrients, anions, and cations. Sediment core samples from above and below the water table were analyzed for organic matter, nutrients, inorganic chemistry, and potential denitrification using denitrification enzyme assays (DEA's) based on the acetylene block technique. Curve fitting of DEA's provided core-scale estimates of microbial populations and growth coefficients. DEA biomass was similar to values obtained with the most probable number technique. Growth coefficients were found to be relatively uniform across the site, while biomass varied by several orders of magnitude. Age dates estimated from Chlorofluorocarbon (CFC) and Sulfur Hexafluoride (SF6), together with analyses of nitrogen species and excess nitrogen gas, provided approximate aquifer-scale, zero-order denitrification rates. The field and laboratory measurements served as input for geostatistical realizations of sediment properties and simulations of reactive transport of nitrate in the saturated zone. Analyses of cores, drillers' logs, and previous interpretations of the local geology were used to generate transition probability models of hydrofacies distributions within Holocene alluvium and pre-Holocene fans, and maps of the boundaries between these stratigraphic sequences. Multiple 3-D realizations were created and ranked based on lateral and vertical bulk-flow properties. For realizations representing a range of geological conditions, 3-D flow was computed with boundary

  9. Ammonia volatilization and availability of Cu, Zn induced by applications of urea with and without coating in soils

    Institute of Scientific and Technical Information of China (English)

    Zhaohui Jiang; Qingru Zeng; Boqing Tie; Bohan Liao; Hejie Pi; Xiaoyou Feng; Yulin Sun

    2012-01-01

    Ammonia volatilization and the distribution of Cu and Zn were investigated in two types of soil treated with coated and uncoated urea.The rate of ammonia volatilization in two weeks after fertilizing with coated urea was 8% in soil 1 (soil derived from river alluvial deposits in Dongting Lake Plain) and 5.15% in soil 2 (red soil derived from quaternary red clay),about half the rates observed when fertilizing with common urea,implying that the hydrolysis speed of the coated urea was lower than for common urea,and that the coated urea can increase nitrogen use efficacy.As for the availability of Cu and Zn,their concentrations decreased in the first week after fertilization,and then increased,which was contrary to the effect of treatment on soil pH.For example,when the pH was 7.99,there was 0.79 mg/kg exchangeable Cu and 0.85 mg/kg exchangeable Zn in the soil derived from river alluvial deposits in Dongting Lake Plain.However,the concentrations of exchangeable Cu and Zn were generally lower for the common urea treatments than those with the coated urea because the peak pH for the common urea treatment was greater.The concentrations of these elements correlated well with pH in the range 4-8 in second order polynomial fits.

  10. The gamma dose assessment and pH correlation for various soil types at Batu Pahat and Kluang districts, Johor, Malaysia

    International Nuclear Information System (INIS)

    An assessment of absorbed dose and radiation hazard index as well as its relationship with soil pH was performed in this study. The area was chosen due to its variety of soil types from the Alluvial and the Sedentary group. The radioactivity concentration levels and the soil acidity were measured using the Canberra GC3518 high pure germanium with a relative efficiency of 35% at 1.3 MeV and the Takemura Soil pH and Moisture Tester (DM15), respectively. Overall results show the Holyrood-Lunas soil of Alluvial group recorded the highest external terrestrial gamma radiation dose rate (TGRD) of 286.4±37.9 nGy h−1 and radioactivity concentrations of 78.1±8.9 Bq kg−1 (226Ra), 410.5±55.4 Bq kg−1 (232Th) and 56.4±8.8 Bq kg−1 (40K), respectively, while the Peat soil of Alluvial group recorded the lowest TGRD of 4.4±2.7 nGy h−1 and radioactivity concentrations of 4.8±1.7 Bq kg−1 (226Ra), 3.1±1.1 Bq kg−1 (232Th) and 6.1±2.0 Bq kg−1 (40K), respectively. The estimated mean outdoor annual effective dose, the mean radium equivalent activity (Req) and the mean external (Hext) and internal hazard index (Hint) associated with the alluvial and sedentary soil group were evaluated at 0.15 and 0.20 mSv, 280 and 364 Bq kg−1, Hext = 0.78 and 1.01, and Hint = 0.93 and 1.26, respectively. Correlation analysis between 238U, 232Th and 40K with soil pH level for alluvial group was r = +0.68, +0.48 and 0, respectively, while for sedentary soil, the Pearson’s, r = −0.30, −0.90 and +0.14, respectively

  11. The gamma dose assessment and pH correlation for various soil types at Batu Pahat and Kluang districts, Johor, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Johar, Saffuwan Mohamed, E-mail: saffuwan@uthm.edu.my [Department of Science, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia (Malaysia); Embong, Zaidi [Department of Science, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia (Malaysia); Research Center for Soft Soil (RECESS), Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia (Malaysia); Tajudin, Saiful Azhar Ahmad [Research Center for Soft Soil (RECESS), Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia (Malaysia)

    2016-01-22

    An assessment of absorbed dose and radiation hazard index as well as its relationship with soil pH was performed in this study. The area was chosen due to its variety of soil types from the Alluvial and the Sedentary group. The radioactivity concentration levels and the soil acidity were measured using the Canberra GC3518 high pure germanium with a relative efficiency of 35% at 1.3 MeV and the Takemura Soil pH and Moisture Tester (DM15), respectively. Overall results show the Holyrood-Lunas soil of Alluvial group recorded the highest external terrestrial gamma radiation dose rate (TGRD) of 286.4±37.9 nGy h{sup −1} and radioactivity concentrations of 78.1±8.9 Bq kg{sup −1} ({sup 226}Ra), 410.5±55.4 Bq kg{sup −1} ({sup 232}Th) and 56.4±8.8 Bq kg{sup −1} ({sup 40}K), respectively, while the Peat soil of Alluvial group recorded the lowest TGRD of 4.4±2.7 nGy h{sup −1} and radioactivity concentrations of 4.8±1.7 Bq kg{sup −1} ({sup 226}Ra), 3.1±1.1 Bq kg{sup −1} ({sup 232}Th) and 6.1±2.0 Bq kg{sup −1} ({sup 40}K), respectively. The estimated mean outdoor annual effective dose, the mean radium equivalent activity (R{sub eq}) and the mean external (H{sub ext}) and internal hazard index (H{sub int}) associated with the alluvial and sedentary soil group were evaluated at 0.15 and 0.20 mSv, 280 and 364 Bq kg{sup −1}, H{sub ext} = 0.78 and 1.01, and H{sub int} = 0.93 and 1.26, respectively. Correlation analysis between 238U, {sup 232}Th and {sup 40}K with soil pH level for alluvial group was r = +0.68, +0.48 and 0, respectively, while for sedentary soil, the Pearson’s, r = −0.30, −0.90 and +0.14, respectively.

  12. The gamma dose assessment and pH correlation for various soil types at Batu Pahat and Kluang districts, Johor, Malaysia

    Science.gov (United States)

    Johar, Saffuwan Mohamed; Embong, Zaidi; Tajudin, Saiful Azhar Ahmad

    2016-01-01

    An assessment of absorbed dose and radiation hazard index as well as its relationship with soil pH was performed in this study. The area was chosen due to its variety of soil types from the Alluvial and the Sedentary group. The radioactivity concentration levels and the soil acidity were measured using the Canberra GC3518 high pure germanium with a relative efficiency of 35% at 1.3 MeV and the Takemura Soil pH and Moisture Tester (DM15), respectively. Overall results show the Holyrood-Lunas soil of Alluvial group recorded the highest external terrestrial gamma radiation dose rate (TGRD) of 286.4±37.9 nGy h-1 and radioactivity concentrations of 78.1±8.9 Bq kg-1 (226Ra), 410.5±55.4 Bq kg-1 (232Th) and 56.4±8.8 Bq kg-1 (40K), respectively, while the Peat soil of Alluvial group recorded the lowest TGRD of 4.4±2.7 nGy h-1 and radioactivity concentrations of 4.8±1.7 Bq kg-1 (226Ra), 3.1±1.1 Bq kg-1 (232Th) and 6.1±2.0 Bq kg-1 (40K), respectively. The estimated mean outdoor annual effective dose, the mean radium equivalent activity (Req) and the mean external (Hext) and internal hazard index (Hint) associated with the alluvial and sedentary soil group were evaluated at 0.15 and 0.20 mSv, 280 and 364 Bq kg-1, Hext = 0.78 and 1.01, and Hint = 0.93 and 1.26, respectively. Correlation analysis between 238U, 232Th and 40K with soil pH level for alluvial group was r = +0.68, +0.48 and 0, respectively, while for sedentary soil, the Pearson's, r = -0.30, -0.90 and +0.14, respectively.

  13. Aggregate Development and Organic Matter Storage in Mediterranean Mountain Soils

    Institute of Scientific and Technical Information of China (English)

    R.M.POCH; M.ANT(U)NEZ

    2010-01-01

    Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied, in order to assess their quality as carbon sinks and also to select the best soil management practices to preserve their quality.Aggregate stability, organic carbon and micromorphology were investigated. The highest amount of organic carbon was found in alluvial, deep soils (228 Mg C ha-1), and the lowest was in a shallow, stony soil with a low plant cover (78 Mg C ha-1). Subsurface horizons of degraded soils under pastures were the ones with smaller and less-stable aggregates.Fresh residues of organic matter (OM) were found mostly in interaggregate spaces. Within the aggregates there were some organic remains that were beginning to decompose, and also impregnative nodules of amorphous OM. Although OM was evenly distributed among the aggregate fractions, the larger blocky peels had more specific surface, contained less decomposed OM and had a lower organic/mineral interphase than smaller crumb aggregates, which were also more stable.Soil carbon storage was affected primarily by the OM inputs in the surface horizons. In order to store organic carbon over the mid- and long-term periods, the mechanisms favouring structuration through biological activity and creating small aggregates with intrapedal stable microporosities seemed to be the most effective.

  14. Electrical Characteristics and Desorption Kinetics of Soil Boron

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The status and activities of boron in soils were studied by the approach of electro-ultrafiltration (EUF). The samples of soils, including brown-red soil and calcareous alluvial soil, were collected from Hubei Province of China. The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment. Filtration and extraction were conducted in accordance with routine process, but fractions in anode and cathode were all collected. Analyses of B, K+, Mg2+, Ca2+, C1- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion-pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil. In studying desorption kinetics with EUF,the boron content of Fractions 2~6 was accumulated, and the accumulative quantities were fit to time factors in three kinetic equations: the zero-order, first-order, and arabolic diffusion equations. Fit degree of the parabolic diffusion equation was the best, followed by the zero-order quation, and the first-order equation was the worst.

  15. Soil friability

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl

    2011-01-01

    for optimal friability. There is a strong need to get more detailed knowledge about effects of soil water content on soil friability and especially to be able to quantify the least limiting water range for soil friability and therefore soil tillage. A strong relationship between organic matter and friability...... has been found but it is not possible to identify a specific lower critical level of organic matter across soil types. Sustainable management of soil requires continuous and adequate inputs of organic matter to sustain or improve soil friability. Intensive tillage and traffic in unfavorable conditions...... threatens soil friability and may initiate a vicious cycle where increasingly higher intensity of tillage is needed to produce a proper seedbed....

  16. An index of ecological integrity for the Mississippi alluvial plain ecoregion: index development and relations to selected landscape variables

    Science.gov (United States)

    Justus, B.G.

    2003-01-01

    Macroinvertebrate community, fish community, water-quality, and habitat data collected from 36 sites in the Mississippi Alluvial Plain Ecoregion during 1996-98 by the U.S. Geological Survey were considered for a multimetric test of ecological integrity. Test metrics were correlated to site scores of a Detrended Correspondence Analysis of the fish community (the biological community that was the most statistically significant for indicating ecological conditions in the ecoregion) and six metrics--four fish metrics, one chemical metric (total ammonia plus organic nitrogen) and one physical metric (turbidity)--having the highest correlations were selected for the index. Index results indicate that sites in the northern half of the study unit (in Arkansas and Missouri) were less degraded than sites in the southern half of the study unit (in Louisiana and Mississippi). Of 148 landscape variables evaluated, the percentage of Holocene deposits and cotton insecticide rates had the highest correlations to index of ecological integrity results. sites having the highest (best) index scores had the lowest percentages of Holocene deposits and the lowest cotton insecticide use rates, indicating that factors relating to the amount of Holocene deposits and cotton insecticide use rates partially explain differences in ecological conditions throughout the Mississippi Alluvial Plain Ecoregion.

  17. Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA

    Science.gov (United States)

    Walls, Susan C.; Waddle, J. Hardin; Faulkner, Stephen P.

    2014-01-01

    We measured amphibian habitat use to quantify the effectiveness of conservation practices implemented under the Wetland Reserve Program (WRP), an initiative of the U.S. Department of Agriculture’s Natural Resources Conservation Service. From February to June 2007, we quantified calling male anurans in cultivated cropland, former cultivated cropland restored through the WRP, and mature bottomland hardwood forest. Sites were located in two watersheds within the Mississippi Alluvial Valley of Arkansas and Louisiana, USA. We estimated detection probability and site occupancy within each land use category using a Bayesian hierarchical model of community species occurrence, and derived an estimate of species richness at each site. Relative to sites in cultivated cropland, nine of 1 l species detected were significantly more likely to occur at WRP sites and six were more likely to occur at forested sites. Species richness estimates were also higher for WRP and forested sites, compared to those in cultivated cropland. Almost half (45 %) of the species responded positively to both WRP and forested sites, indicating that patches undergoing restoration may be important transitional habitats. Wetland Reserve Program conservation practices are successful in restoring suitable habitat and reducing the impact of cultivation-induced habitat loss on amphibians in the Mississippi Alluvial Valley.

  18. Characteristics of the gravel size and potassium in the Ejin Alluvial Fan from remote sensing images and stratigraphic section

    Science.gov (United States)

    Zhang, Lu; Guo, Huadong; Wang, Qinjun

    2014-03-01

    The Ejin Alluvial Fan (EAF), located in the north-west of China, is an important recorder of both paleoclimatic and tectonic information of the north margin of the Qinghai-Tibet Plateau. Remote sensing technics, including optical and microwave sensors, have been the key spatial observation tools to extract the surface information related to the paleoenvironment. In this paper, the gravel size and chemical element potassium K distributions of the EAF were obtained from RadarSat-2 Synthetic Aperture Radar (SAR) data and LandSat TM optical data, respectively. In addition, the stratigraphic section of the EAF was established and the corresponding geological information in the vertical direction with different periods was obtained. Combining the geological survey information and surface distribution information, it can be concluded as follows. 1) The EAF covers an area of above 30,000 km2 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.

  19. Ground motions around a semi-circular valley partially filled with an inclined alluvial layer under SH-polarized excitation

    Science.gov (United States)

    Chang, Kao-Hao; Tsaur, Deng-How; Wang, Jeen-Hwa

    2014-12-01

    A simplified mathematical model, composed of a semi-circular valley partially filled with an inclined alluvial layer under plane SH-wave incidence, is presented. To evaluate the site response theoretically, a rigorous series solution is derived via the region-matching technique. For angular wavefunctions constrained by an inclined free surface, the original form of Graf's addition formula is recast to arbitrarily shift the local coordinate system. The valley geometry, filling material, angle of incidence, and wave frequency are taken as significant parameters in exploring the site effect on ground motions. Also included are the frequency- and time-domain computations. Two canonical cases, the semi-circular vacant canyon and the fully filled semi-circular alluvial valley, with exact analytical solutions, and the partly horizontally filled case previously studied, are taken to be particular cases of the proposed general model. Steady-state results show that the peak amplitudes of motion may increase at low frequencies when the filling layer inclines to the illuminated region. At low-grazing incidence, the phenomenon of wave focusing becomes evident on the shadow side of the filling layer. Transient-state simulations elucidate how a sequence of surface waves travel on the topmost alluvium along opposite directions and interfere with multiple reflected waves within the filling layer.

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

    Science.gov (United States)

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

    2012-04-01

    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. Analysis of Nitrogen Pollution Load by Domestic Waste Water Treatment in the Tedori River Alluvial Fan Areas

    Science.gov (United States)

    Maruyama, Toshisuke; Noto, Fumikazu; Takahashi, Tsuyoshi; Tsuchihara, Takeo; Tanaka, Tadashi

    An evaluation of the environment nitrogen pollution load with regard to domestic waste water treatment on the Tedori River Alluvial Fan Areas was conducted. The literature-based water quality data collected before and after the treatment and the basic outflow pollution unit was determined for the several water treatment systems. Next these data were applied for the entire alluvial fan areas resulting in an estimated total nitrogen pollution load of as 186 ton/year. 58% of the total nitrogen pollution load was estimated to be from the private residences that were not connected to the public sewage system (connecting ratio 90.5%) which thus had relation to the pollution of groundwater and water quality in the drainage canal in the region under consideration. The nitrogen pollution load was higher in the urban area more than the rural. The rural domestic waste water system accounted for about 17.9% of the total pollution load, which carried a high probability of groundwater pollution because of seepage or percolation. The pollution load from the direct flow of the public sewage treatment water to the middle stream of the Tedori River, together with the water from small companies and untreated water from local family dwellings made up about 3-10% of total pollution.

  2. Assessment of Intrinsic Vulnerability to Contamination for the Alluvial Aquifer in El-Fayoum Depression Using the Drastic Method

    International Nuclear Information System (INIS)

    Intrinsic vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. The vulnerability for the alluvial aquifer in El-Fayoum depression was assessed by applying the Drastic model as well as utilizing sensitivity analyses to evaluate the reliability of this model. This method uses seven parameters including climatic, geological, and hydrogeological conditions controlling the seepage of pollutant substances to groundwater. Vulnerability maps were produced by applying the Generic and Agricultural models according to the Drastic charter. The resulting agricultural Drastic vulnerability map indicates that 23.3%, 22.7% and 12.4% of El-Fayoum depression is under low, low-moderate and moderately high vulnerability of groundwater contamination, respectively, while 41.6% of the area of study can be designated as an area of moderate vulnerability of groundwater contamination. Resulting maps revealed that the potential for polluting groundwater with agricultural chemicals is greater than with Generic Drastic index pollutants. Depth to water table parameter inflicted the largest impact on the intrinsic vulnerability of the alluvial aquifer in El-Fayoum depression. Both the map removal and single-parameter sensitivity analyses indicated that the vulnerability index is the least sensitive to the removal of the recharge and hydraulic conductivity parameters but is highly sensitive to the removal of depth to water parameter.

  3. Soil formation.

    NARCIS (Netherlands)

    Breemen, van N.; Buurman, P.

    1998-01-01

    Soil Formation deals with qualitative and quantitative aspects of soil formation (or pedogenesis) and the underlying chemical, biological, and physical processes. The starting point of the text is the process - and not soil classification. Effects of weathering and new formation of minerals, mobilis

  4. Integrative geomorphological mapping approach for reconstructing meso-scale alluvial fan palaeoenvironments at Alborz southern foothill, Damghan basin, Iran

    Science.gov (United States)

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

    2013-04-01

    Alluvial fans and aprons are common depositional features in general Iranian geomorphology. The countries major cities as well as settlements and surrounding area have often been developed and been built up on this Quaternary sediment covers. Hence they periodically face the effects of varying fluvial and slope-fluvial activity occurring as part of this geosystem. The Geological Survey of Iran therefore supports considerable efforts in Quaternary studies yielding to a selection of detailed mapped Quaternary landscapes. The studied geomorphologic structures which are settled up around an endorheic basin in Semnan Province represent a typical type of landform configuration in the area. A 12-km-transect was laid across this basin and range formation. It is oriented in north-south direction from the southern saltpan, called "Kavir-e-Haj Aligholi"/"Chah-e-Jam" ("Damghan Kavir"), across a vast sandy braided river plain, which is entering from the north east direction of the city of Shahroud. At its northern rim it covers alluvial sediment bodies, which are mainly constituted by broad alluvial aprons, fed by watersheds in Alborz Mountains and having their genetic origins in Mio-/Pliocene times. During this study a fully analytical mapping system was used for developing a geodatabase capable of integrating geomorphological analyses. Therefore the system must provide proper differentiation of form, material and process elements as well as geometric separation. Hence the German GMK25 system was set up and slightly modified to fit to the specific project demands. Due to its structure it offers most sophisticated standards and scale independent hierarchies, which fit very well to the software-determinated possibilities of advanced geodatabase applications. One of the main aspects of mapping Quaternary sediments and structures is to acquire a proper description and systematic correlation and categorization of the belonging mapping-objects. Therefore the team from GSI and

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

    Science.gov (United States)

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

    2016-04-01

    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. Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma

    Science.gov (United States)

    Ryter, Derek W.; Correll, Jessica S.

    2016-01-14

    This report describes a study of the hydrology, hydrogeological framework, numerical groundwater-flow models, and results of simulations of the effects of water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma. The purpose of the study was to provide analyses, including estimating equal-proportionate-share (EPS) groundwater-pumping rates and the effects of projected water use and droughts, pertinent to water management of the Beaver-North Canadian River alluvial aquifer for the Oklahoma Water Resources Board.

  7. New morpho-stratigraphic constraints for the evolution of the alluvial fan system along the northern slopes of the Taburno-Camposauro Mountains (Calore River basin, Southern Italy)

    Science.gov (United States)

    Leone, Natalia; Amato, Vincenzo; Aucelli, Pietro P. C.; Cesarano, Massimo; Filocamo, Francesca; Petrosino, Paola; Rosskopf, Carmen M.; Valente, Ettore; Giralt, Santiago; Casciello, Emilio

    2016-04-01

    The Lower Calore River Valley is a morphostructural depression located in the inner sector of the Campanian Apennine, between the Taburno-Camposauro and the Matese carbonate massifs. The river is the main left tributary of the Volturno River, it has a meandering channel partially structural-controlled. Numerous morphotectonic clues and historical seismicity data suggest that this part of the Apennine chain was particularly active during the late-Quaternary. In detail, the valley is E-W oriented and presents an asymmetry of the opposed valley slopes. The left side, corresponding to the northern flank of the Camposauro massif, is characterized by a steep slope (70°-35°), partially controlled by a ~E-W oriented fault system, and by a wide less-inclined piedmont aggradation zone. The latter started growing since middle Pleistocene, with the deposition of alluvial fans and slope deposits over the well cemented early Pleistocene breccias of Laiano Synthem. The alluvial fan deposition has been active until present giving rise to three main generations of alluvial fans. The right side of the valley, instead, is characterized by seven orders of fluvial terraces, both of erosional and depositional origin. The quaternary morpho-stratigraphic evolution of alluvial fans and fluvial terraces has been strongly conditioned by the interaction of tectonic phases and climatic variations. A detailed geomorphological study (1:5.000 in scale) was carried out with the aim to map the main depositional and erosional fluvial landforms and to identify the main tectonic lineaments of the area. A detailed field survey allowed to better define the stratigraphic and paleoenvironmental context in which the alluvial deposits developed and also to find chrono-stratigraphic markers. Tephra-stratigraphic analyses were performed on pyroclastic deposits interbedded into the alluvial fan and fluvial successions. At the moment the age of the first generation of alluvial fans is still under

  8. Alluvial xenotime and heavy minerals assemblage from the northern edge of Nisa-Albuquerque Batholith, eastern Portugal : provenance and geochemical implications

    OpenAIRE

    Salgueiro, Rute; Rosa, Diogo R. N.; Inverno, Carlos; Oliveira, Daniel P. S.; Solá, Ana Rita; Guimarães, Fernanda M. G.

    2014-01-01

    Alluvial xenotime and heavy minerals assemblage from the northern edge of Nisa-Albuquerque Batholith, eastern Portugal : provenance and geochemical implications / Rute Salgueiro... [et al.]. - Amsterdam : Elsevier, 2014. - [18] p. : il., 13 figuras e 8 tabelas ; 30 cm The xenotime-bearing heavy mineral assemblages present in the alluvial samples from Vila Velha de Ródão, Nisa, Póvoa e Meadas and Sto. António das Areias, localized in the northern edge of Nisa-Albuquerque Batholith,...

  9. Soil metagenomics and tropical soil productivity

    OpenAIRE

    Garrett, Karen A.

    2009-01-01

    This presentation summarizes research in the soil metagenomics cross cutting research activity. Soil metagenomics studies soil microbial communities as contributors to soil health.C CCRA-4 (Soil Metagenomics)

  10. Soils - Volusia County Soils (Polygons)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Soils: 1:24000 SSURGO Map. Polygon boundaries of Soils in Volusia County, downloaded from SJRWMD and created by NRCS and SJRWMD. This data set is a digital version...

  11. Geochemical proxies for weathering and provenance of Late Quaternary alluvial core-sediments from NW India

    Science.gov (United States)

    Singh, Ajit; Amir, Mohd; Paul, Debajyoti; Sinha, Rajiv

    2014-05-01

    The Indo-Gangetic alluvial plains are formed by sediment deposition in the foreland basin as a result of upliftment and subsequent erosion of the Himalaya. Earlier study (Sinha et al., 2013) has shown the subsurface existence of buried channel bodies beneath the Ghaggar plains in NW Indo-Gangetic plains. The mapped sand bodies follow trace of a paleochannel that begins at the mountain front near the exit of river Sutlej and extends to the northern margin of the Thar desert, suggesting existence of a large Himalayan-sourced river (Singh et al., 2011) in the past. The buried sand bodies hold potential records of erosion history over the Himalaya that could be used to assess climate-controlled erosion over the Himalaya. Geochemical variations in the sediments from two (~45m long) cores drilled below the trace of the paleochannel (upstream) near Sirhind, Punjab and two cores (GS-10 & 11) from downstream near Kalibangan, Rajasthan, are used in this study to understand the erosional pattern over the Himalaya during Late Quaternary. Down-core variations in chemical index of alteration (CIA=51-79) along with K2O/Na2O and Al2O3/(CaO+Na2O) ratios are consistent with the trends of SW summer monsoonal fluctuations during the Glacial-Interglacial periods indicating climate controlled weathering at the source; higher values during Interglacial and lower during Glacial periods with maximum value during the Holocene. Sr-Nd isotopic compositions of drill-cores sediments, 87Sr/86Sr (0.7314-0.7946), ɛNd (-23.2 to -14) are within the range of silicate rocks from the Higher and Lesser Himalaya. Significant down-core variations in 87Sr/86Sr and ɛNd are observed that reflect the mixing of varying proportions of the Higher and Lesser Himalayan sediments, the two dominant sources to the core sites. Sediments deposited during MIS-2 and MIS-4, cold and dry Glacial periods, show high 87Sr/86Sr and low ɛNd suggesting an enhanced contribution from the Lesser Himalayan rocks that are

  12. Species richness and relative abundance of breeding birds in forests of the Mississippi Alluvial Valley

    Science.gov (United States)

    Nelms, C.O.; Twedt, D.J.

    1993-01-01

    In 1992, the Vicksburg Field Research Station of the National Wetlands Research Center initiated research on the ecology of migratory birds within forests of the Mississippi Alluvial Valley (MAV). The MAV was historically a nearly contiguous bottomland hardwood forest, however, only remnants remain. These remnants are fragmented and often influenced by drainage projects, silviculture, agriculture, and urban development. Our objectives are to assess species richness and relative abundance, and to relate these to the size, quality, and composition of forest stands. Species richness and relative abundance were estimated for 53 randomly selected forest sites using 1 to 8 point counts per site, depending on the size of the forest fragment. However, statistical comparisons among sites will be restricted to an equal number ofpoint counts within the sites being compared. Point counts, lasting five minutes, were conducted from 11 May to 29 June 1992, foltowing Ralph, Sauer, and Droege (Point Count Standards; memo dated 9 March 1992). Vegetation was measured at the first three points on each site using a modification of the methods employed by Martin and Roper (Condor 90: 5 1-57; 1988). During 252 counts, 7 1 species were encountered, but only 62 species were encountered within a 50-m radius of point center. The mean number of species encountered within 50 m of a point, was 7.3 (s.d. = 2.7) and the mean number of individuals was 11.2 (s.d. = 4.2). The mean number of species detected at any distance was 9.6 (s.d, = 2.8) and the mean number of individuals was 15.6 (s.d. = 7.9). The most frequently encountered warblers in the MAV were Prothonotary Warbler and Northern Parula. Rarely encountered warblers were American Redstart and Worm-eating Warbler. The genera, Quercus, Ulmus, Carya, and Celtis were each encountered at 80 or more of the 152 points at which vegetation was sampled. Species most frequentlyencountered were: sugarberry (Celtis laevagata), water hickory (Caqa

  13. Comparative Assessment of Soil Contamination by Lead and Heavy Metals in Riparian and Agricultural Areas (Southern Québec, Canada)

    OpenAIRE

    Francis Baril; Julien St-Laurent; Marlies Hähni; Diane Saint-Laurent

    2010-01-01

    Soils contaminated with hydrocarbons (C10–C50), PAHS, lead and other heavy metals were recently found in the banks of two major rivers in southern Québec. Alluvial soils are contaminated over a distance of 100 kilometers. Eight sampling sites, including some located in agriculture areas (farm woodlots) have been selected to compare air pollution (aerosol fallout and rainout) and river pollution values. The concentrations detected in soil profiles for As, Cd and Pb vary between 3.01 to 37.88 m...

  14. Soil infiltrometer

    Energy Technology Data Exchange (ETDEWEB)

    Mehler, M.R.

    1990-09-18

    This patent describes an infiltrometer useful for field testing soil permeability. It comprises: a large reservoir having an open bottom resting on the soil; a small reservoir having an open bottom resting on the soil, the small reservoir being positioned within the large reservoir; the small reservoir comprising a relatively large receptacle adjacent the soil and a relatively small receptacle connected thereto and extending upwardly therefrom; the volume of the large reservoir greatly exceeding the volume of the small reservoir; the ratio of the upper surface area of liquid in the large reservoir to the surface area of the soil covered thereby greatly exceeding the ratio of the upper surface area of liquid in the relatively small receptacle of the small reservoir to the surface area of the soil covered thereby; and means for determining the amount of liquid from the small reservoir permeating into the soil.

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

    Science.gov (United States)

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

    2016-04-01

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

  16. Use of water from small alluvial aquifers for irrigation in semi-arid regions Uso das águas de pequenos aquíferos aluviais para irrigação nas regiões semiáridas

    Directory of Open Access Journals (Sweden)

    Julien Daniel Pierre Burte

    2011-09-01

    Full Text Available Water from small alluvial aquifers constitutes an attractive and low-cost option for irrigation and rural development in Northeastern Brazil. Based on piezometric measurements, geochemical analyses and electrical conductivity estimates, the present case study identified the main processes determining the hydrosaline dynamics of an alluvial aquifer in a small watershed inserted in the crystalline bedrock of a semi-arid region in Ceará and evaluated the availability of water for irrigation. Accumulation of salts in soil are related to evaporative flux from the aquifer and is increased by irrigation from the groundwater of the alluvial aquifer. The water in these aquifers may be used for irrigation, but represents a risk of soil salinization and alkalinization. Integrated management of surface and underground water resources in the Forquilha watershed may help control irrigation water quality (salinity and residual alkalinity, thereby rationalizing the use of local reservoirs and minimizing losses from evaporation. It has to take into account the complex dynamic of salts and water between the reservoirs, release of water into the river, floods and irrigations.A agricultura irrigada a partir da água subterrânea dos pequenos aqüíferos aluviais é uma alternativa interessante e de baixo custo para o desenvolvimento do meio rural no Nordeste brasileiro. A partir de um estudo de caso numa micro-bacia no centro da área cristalina do semiárido cearense é analisada a contribuição de características físicas (piezometria, geoquímicas e de modelos (de balanço hidrológico e de massa para identificar a origem e os principais processos que governam a dinâmica da salinidade das águas de um pequeno aqüífero aluvial e avaliar a disponibilidade de água para irrigação. A irrigação conduz a uma redistribuição dos sais da zona saturada para a zona não saturada do aqüífero, podendo ocorrer acumulação. Devido as suas características, as

  17. Downhole instrumentation for the evaluation of non-linear soil response on ground surface motion

    International Nuclear Information System (INIS)

    A downhole experiment at McGee Creek in eastern central California has shown that, for hard soil deposits, the one-dimensional shear-wave model for the soil constitutive relationship is adequate for use in the computation of ground surface motions. In order to investigate the influence of soil non-linearities on these latter, an alluvial site has been instrumented in southern California, at Garner Valley. This paper presents the characterization of the site and the soil parameters derived from in-site and laboratory-based tests. Preliminary results for the recorded ground motion responses corresponding to small-magnitude earthquakes are compared with computed motions from a one-dimensional shear-wave model. (author)

  18. Comparison of high-resolution P- and SH-wave reflection seismic data in alluvial and pyroclastic deposits in Indonesia

    Science.gov (United States)

    Wiyono, Wiyono; Polom, Ulrich; Krawczyk, Charlotte M.

    2013-04-01

    Seismic reflection is one of the stable methods to investigate subsurface conditions. However, there are still many unresolved issues, especially for areas with specific and complex geological environments. Here, each location has an own characteristic due to material compounds and the geological structure. We acquired high-resolution, P-and SH-wave seismic reflection profiles at two different locations in Indonesia. The first location was in Semarang (Central Java) and the second one was in Tiris (East Java). The first region is located on an alluvial plain with thick alluvial deposits of more than 100 m estimated thickness, and the second location was located on pyroclastic deposit material. The seismic measurements for both locations were carried out using a 48-channel recording system (14-Hz P-wave, 10-Hz SH-wave geophones) with geophone intervals of 5 m (P-waves) and 1 m (SH-waves), respectively. The seismic source for the P-wave was a ca. 4 kg sledge hammer which generated a seismic signal by by hitting on an aluminum plate of 30x30 cm, whereas the SH-wave source was a mini-vibrator ELVIS (Electrodynamic Vibrator System), version 3. Thirteen seismic profiles at Semarang and eighth profiles at Tiris were acquired. The results of seismic data in Semarang show fair to good seismic records for both P-and SH-waves. The raw data contain high signal-to-noise-ratio. Many clear reflectors can be detected. The P-wave data shows reflectors down to 250 ms two-way time while the SH-wave records show seismic events up to 600 ms two-way time. This result is in strong contrast to the seismic data result from the Tiris region. The P-wave data show very low signal to noise ratio, there is no reflection signal visible, only the surface waves and the ambient noise from the surrounding area are visible. The SH-waves give a fair to good result which enables reflector detection down to 300 ms two-way time. The results from the two seismic campaigns show that SH-wave reflection

  19. Shallow subsurface stratigraphy and alluvial architecture of the Kosi and Gandak megafans in the Himalayan foreland basin, India

    Science.gov (United States)

    Sinha, Rajiv; Ahmad, Jawed; Gaurav, Kumar; Morin, Guillaume

    2014-03-01

    The Kosi and the Gandak are two major Himalayan tributaries of the Ganga River in the north Bihar plains India. With a large hinterland in the Nepal Himalaya, both these rivers have generated megafans in the plains over the Quaternary time scale. Both these rivers are known to be highly dynamic and sediment-charged. A few conceptual models and limited field data suggested that these megafans have produced thick sand sheets over Late Quaternary period but these ideas have remained speculative and there is no data on the size and dimension of these sand bodies. This paper attempts to reconstruct the subsurface stratigraphy and alluvial architecture for the upper ~ 100 m of the megafans based on electrical resistivity soundings, borehole data and drill cores. Alluvial architecture of the Kosi megafan shows significant variability from proximal to medial parts of the fan in terms of sediment grain size and layer thicknesses. While the medial part shows ~ 20-30 m thick medium to coarse sand sheets which are laterally stacked, the proximal part of the fan has a dominantly gravel unit below ~ 15 m depth that is underlain and overlain by medium to coarse sand units. Further, the medial fan also shows significant vertical and lateral variability in alluvial stratigraphy. The near-surface (river whereas the lower succession shows narrow but thick sand fills reflecting incised channels. The western part of the Gandak megafan has more abundant sand bodies compared to the eastern side of the river along both transects. There are no significant differences between proximal and medial transects across the Gandak megafan. The absence of gravel deposits in the shallow subsurface of the Gandak megafan may be attributed to the presence of a prominent intermontane valley in the hinterland of the Gandak river which has acted as a 'sediment filter' thereby trapping most of the coarser fraction. On the other hand, the Kosi river exits directly through the mountain front, and therefore

  20. Controls on morphometry and morphology of alluvial and colluvial fans in the high-Arctic setting, Petuniabukta, Svalbard.

    Science.gov (United States)

    Tomczyk, Aleksandra; Ewertowski, Marek

    2016-04-01

    The Petuniabukta (78o42' N, 16o32') is a bay in the northern part of Billefjorden in the central part of Spitsbergen Island, Svalbard. The bay is surrounded by six major, partly glaciated valleys. A numerous alluvial and colluvial fans have developed within valleys as well as along the fiord margins. Distribution and characterization of morphometric parameters of fans were investigated using time-series of orthophotos and digital elevation models (generated based on 1961, 1990, 2009 aerial photographs) and high resolution satellite imagery from 2013. In addition, a very detailed DEM and orthophoto (5 cm resolution) have been produced from unmanned aerial vehicle (UAV) imagery from 2014 and 2015, covering three fans characterised by different types of surface morphology. A 1:40,000 map showing the distribution of almost 300 alluvial and colluvial fans (ranging in area from 325 km2 to 451 275 km2), together with time-series of 1:5,000 geomorphological maps of sample fans enabled an assessment of the spatial and temporal evolution of processes responsible for delivery and erosion of sediments from the fans. The relationship between terrain parameters (e.g. slope, exposition) as well as geology was also investigated. Many of the studied alluvial fans were at least partly coupled and sediments were transferred from the upstream zone to the downstream zone, either due to debris-flow or channelized stream flow. In other cases, coarse sediments were stored within fans, and fines were transported downstream by sheet flows or sub-surface flows. In most of smaller colluvial fans and debris cones, sediments were delivered by mass movement processes (mainly rockfalls and snowfalls) and did not reach lower margin of landforms. Analysis of historical aerial photographs indicated recent increase in the activity of debris-flow modification of surface morphology of fans. Fans located outside limits of the Little Ice Age (LIA) glaciation are dominated by the secondary processes

  1. Soil bearing capacity under dynamic conditions for the ALWR systems

    International Nuclear Information System (INIS)

    The present work is a part of the studies carried out by ENEL DSR-VDN and ISMES on ALWR systems. From a geotechnical point of view the soil bearing capacity in dynamic stress conditions is of particular interest for the development of the ALWR project. In fact the possible Italian sites are not rocky sites but generally of alluvial kind. This work is a continuation of a previous paper. Here we show the results of the finite element soil-structure analysis and the subsequent bearing capacity analysis with reference to four geotechnical profiles that represent the lower and upper bound of the Italian variability range of data. Some comments are made on the codes of practice, of interest to Italy, the safety factor concept and the possible use of other calculation methods in addition to classical ones. (author)

  2. Soil Physics

    Science.gov (United States)

    Marshall, T. J.; Holmes, J. W.; Rose, C. W.

    1996-06-01

    Now in its third edition, this textbook gives a comprehensive account of soil physics with emphasis on field applications for students and research workers engaged in water resources studies, soil sciences, and plant sciences. The authors have added chapters on soil erosion, conservation, and the role of soil in affecting water quality to this new edition. The book gives an account of how water influences the structure and strength of soil; how plants absorb water from soils; how water from rain and irrigation enters the soil and flows through it to contribute to stream flow and flow in artificial drains; how soluble salts and chemical pollutants are transported; how soils are eroded by water and wind; and how the evaporation rate from the land surface is influenced by soil water supply, the nature of the plant cover and the evaporative power of the atmosphere. This book will be useful to students and research workers in environmental sciences, hydrology, agriculture, soil science, and civil engineering.

  3. Water retention and availability in soils of the State of Santa Catarina-Brazil: effect of textural classes, soil classes and lithology

    Directory of Open Access Journals (Sweden)

    André da Costa

    2013-12-01

    Full Text Available The retention and availability of water in the soil vary according to the soil characteristics and determine plant growth. Thus, the aim of this study was to evaluate water retention and availability in the soils of the State of Santa Catarina, Brazil, according to the textural class, soil class and lithology. The surface and subsurface horizons of 44 profiles were sampled in different regions of the State and different cover crops to determine field capacity, permanent wilting point, available water content, particle size, and organic matter content. Water retention and availability between the horizons were compared in a mixed model, considering the textural classes, the soil classes and lithology as fixed factors and profiles as random factors. It may be concluded that water retention is greater in silty or clayey soils and that the organic matter content is higher, especially in Humic Cambisols, Nitisols and Ferralsol developed from igneous or sedimentary rocks. Water availability is greater in loam-textured soils, with high organic matter content, especially in soils of humic character. It is lower in the sandy texture class, especially in Arenosols formed from recent alluvial deposits or in gravelly soils derived from granite. The greater water availability in the surface horizons, with more organic matter than in the subsurface layers, illustrates the importance of organic matter for water retention and availability.

  4. Meteorological tower data for the Yucca Alluvial (YA) site and Yucca Ridge (YR) site: Final data report, July 1983-October 1984

    International Nuclear Information System (INIS)

    The purpose of the NNWSI meteorological data collection program was to support environmental evaluations of site suitability for a nuclear waste repository. This is the last of a series of data summaries for the NNWSI Alluvial and Ridge Sites in southern Nevada. 3 refs., 3 figs., 6 tabs

  5. The Effect of Chloride and Sulfate Ions on the Adsorption of Cd2+ on Clay and Sandy Loam Egyptian Soils

    OpenAIRE

    EL-Hefnawy, Mohamed E.; Selim, Elmetwaly M.; Assaad, Faiz F.; Ismail, Ali I.

    2014-01-01

    Adsorption of Cd2+ on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts. Kinetics and thermodynamic parameters of the adsorption were calculated at two different electrolyte concentrations: 0.05 N and 0.15 N. The adsorption was described by Langmuir and Freundlich isotherms. Results showed that lower concentration of the NaCl or Na2SO4 electrolytes (0....

  6. Activity ratios of (234)U/(238)U and (226)Ra/(228)Ra for transport mechanisms of elevated uranium in alluvial aquifers of groundwater in south-western (SW) Punjab, India.

    Science.gov (United States)

    Kumar, A; Karpe, R K; Rout, S; Gautam, Y P; Mishra, M K; Ravi, P M; Tripathi, R M

    2016-01-01

    The concentrations of total dissolved uranium (U), its isotopic composition ((234)U, (235)U, (238)U) and two long lived Ra isotopes ((226)Ra and (228)Ra) in alluvial aquifers of groundwater were determined to investigate the groundwater flow pattern in the south-western (SW) Punjab, India. Particular attention was given to the spatial variability of activity ratios (ARs) of (234)U/(238)U and (226)Ra/(228)Ra to predict the possible sources and supply process of U into the water from the solid phase. The measured groundwater (234)U/(238)U ARs were ∼1 or >1 in the shallow zone (depth  30 m) with relatively low U concentration. The simultaneous elevated U concentration and (234)U/(238)U ARs in waters were possibly due to differences in imprints of rock-water interactions under hydrologic conditions. However, (234)U/(238)U ARs geochemistry of the two isotopes. On the other hand, (226)Ra/(228)Ra ARs in groundwaters varied widely and observed about 50-300 times higher than (238)U/(232)Th ARs in granitic rocks or soils. Such elevation in ARs might be attributed to different dissolution properties of their parents during water-rock interactions or lattice damage during decay or local enrichments of uranium in the aquifers. PMID:26555366

  7. Depositional conditions on an alluvial fan at the turn of the Weichselian to the Holocene – a case study in the Żmigród Basin, southwest Poland

    Directory of Open Access Journals (Sweden)

    Zieliński Paweł

    2016-06-01

    Full Text Available Presented are the results of research into the fluvio-aeolian sedimentary succession at the site of Postolin in the Żmigród Basin, southwest Poland. Based on lithofacies analysis, textural analysis, Thermoluminescence and Infrared-Optical Stimulated Luminescence dating and GIS analysis, three lithofacies units were recognised and their stratigraphic succession identified: 1 the lower unit was deposited during the Pleni-Weichselian within a sand-bed braided river functioning under permafrost conditions within the central part of the alluvial fan; 2 the middle unit is the result of aeolian deposition and fluvial redeposition on the surface of the fan during long-term permafrost and progressive decrease of humidity of the climate at the turn of the Pleni- to the Late Weichselian; 3 the upper unit accumulated following the development of longitudinal dunes at the turn of the Late Weichselian to the Holocene; the development of dunes was interrupted twice by the form being stabilised by vegetation and soil development.

  8. Soils recovery by means of the incorporation of green manure in agricultural systems

    International Nuclear Information System (INIS)

    Recent alluvial soils have borne intensive agriculture couple with the corresponding abuse of agricultural machinery for soil preparation produce losses in its productivity .the present work raises as hypothesis using green manure to restore soil fertility and productivity as well as crop productivity. It was selected a productive corn farm in the Aria ri alluvial plain with soil physical and chemical problems; in the a/95 semester it was sown to corn as monocultures and associated to vitabosa (Stizolobium deeringianum) and canavalia (Cannavalia ensiformis) and three N levels: 0,80 y 100 kg/ha; in the B/95 semester it was sown to corn as monocultures to look at residual effects of green manure. A randomised block design with three replications was applied. In the first harvest a non-significant response (Tukey 0.05) to N application was observed, obtaining the major yield of 1.71 and 1.47 ton/ha in monocultures and associated in the 100-kg/ha levels. The incorporated material to the soil caused by the association (2.8 to 5.3 ton/ha) was higher than the monocultures; likewise the nutrient content; vitabosa yield higher N, P and Mg than canavalia and the latter one higher K and Ca, obtaining greater production of maize 1.18 to 2.16 ton/ha. For the third harvested though it was observed in the soil equal organic matter content and a slight increase of P, Ca and Mg corn yield was low (0.52 to 1.5 ton/ha) and similar to the first crop, which indicates a rapid benefit in the soil as a nutrient liberator and slow effect on soil physical properties, observing decreasing in resistance values but high values of bulk density and slow basic infiltration

  9. A new methodology for the quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding (MBES)

    Science.gov (United States)

    Best, Jim; Simmons, Stephen; Parsons, Daniel; Oberg, Kevin; Czuba, Jonathan; Malzone, Chris

    2010-01-01

    In order to investigate the interactions between turbulence and suspended sediment transport in natural aqueous environments, we ideally require a technique that allows simultaneous measurement of fluid velocity and sediment concentration for the whole flow field. Here, we report on development of a methodology using the water column acoustic backscatter signal from a multibeam echo sounder to simultaneously quantify flow velocities and sediment concentrations. The application of this new technique is illustrated with reference to flow over the leeside of an alluvial sand dune, which allows, for the first time in a field study, quantitative visualization of large-scale, whole flow field, turbulent coherent flow structures associated with the dune leeside that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows.

  10. A new methodology for the quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding (MBES)

    Science.gov (United States)

    Best, Jim; Simmons, Stephen; Parsons, Daniel; Oberg, Kevin; Czuba, Jonathan; Malzone, Chris

    2010-03-01

    In order to investigate the interactions between turbulence and suspended sediment transport in natural aqueous environments, we ideally require a technique that allows simultaneous measurement of fluid velocity and sediment concentration for the whole flow field. Here, we report on development of a methodology using the water column acoustic backscatter signal from a multibeam echo sounder to simultaneously quantify flow velocities and sediment concentrations. The application of this new technique is illustrated with reference to flow over the leeside of an alluvial sand dune, which allows, for the first time in a field study, quantitative visualization of large-scale, whole flow field, turbulent coherent flow structures associated with the dune leeside that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows.

  11. Seismic Wave Amplification in 3D Alluvial Basins: 3D/1D Amplification Ratios from Fast Multipole BEM Simulations

    CERN Document Server

    Fajardo, Kristel C Meza; Chaillat, Stéphanie; Lenti, Luca

    2016-01-01

    In this work, we study seismic wave amplification in alluvial basins having 3D standard geometries through the Fast Multipole Boundary Element Method in the frequency domain. We investigate how much 3D amplification differs from the 1D (horizontal layering) case. Considering incident fields of plane harmonic waves, we examine the relationships between the amplification level and the most relevant physical parameters of the problem (impedance contrast, 3D aspect ratio, vertical and oblique incidence of plane waves). The FMBEM results show that the most important parameters for wave amplification are the impedance contrast and the so-called equivalent shape ratio. Using these two parameters, we derive simple rules to compute the fundamental frequency for various 3D basin shapes and the corresponding 3D/1D amplification factor for 5% damping. Effects on amplification due to 3D basin asymmetry are also studied and incorporated in the derived rules.

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

    Science.gov (United States)

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

    2015-08-01

    The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

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

    Science.gov (United States)

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

    2012-06-01

    For some decades, mass wasting processes such as landslides and debris floods have been threatening villages and transportation routes in the Rio Grande Valley, named Quebrada de Humauhuaca. One of the most significant examples is the urban area of Tilcara, built on a large alluvial fan. In recent years, debris flood phenomena have been triggered in the tributary valley of the Huasamayo Stream and reached the alluvial fan on a decadal basis. In view of proper development of the area, hazard and risk assessment together with risk mitigation strategies are of paramount importance. The need is urgent also because the Quebrada de Humahuaca was recently included in the UNESCO World Cultural Heritage. Therefore, the growing tourism industry may lead to uncontrolled exploitation and urbanization of the valley, with a consequent increase of the vulnerability of the elements exposed to risk. In this context, structural and non structural mitigation measures not only have to be based on the understanding of natural processes, but also have to consider environmental and sociological factors that could hinder the effectiveness of the countermeasure works. The hydrogeological processes are described with reference to present-day hazard and risk conditions. Considering the socio-economic context, some possible interventions are outlined, which encompass budget constraints and local practices. One viable solution would be to build a protecting dam upstream of the fan apex and an artificial channel, in order to divert the floodwaters in a gully that would then convey water and sediments into the Rio Grande, some kilometers downstream of Tilcara. The proposed remedial measures should employ easily available and relatively cheap technologies and local workers, incorporating low environmental and visual impacts issues, in order to ensure both the future conservation of the site and its safe exploitation for inhabitants and tourists.

  14. Controls on the Alluviation of Oxbow Lakes by Bed Load as Observed Along the Sacramento River of California

    Science.gov (United States)

    Constantine, J. A.; Dunne, T.; Piegay, H.; Kondolf, G. M.

    2007-12-01

    As the products of meander cutoff that are widespread within many floodplains, oxbow lakes can affect the ability of rivers to migrate across their valleys, as well as physical and chemical exchanges between the river and floodplain environment. The particular functions of the oxbow lake are determined by the manner it is filled by sedimentation. Although the alluviation of oxbow lakes has been observed in natural settings and generalized by means of rules in planform evolution models, no theory exists to explain how oxbow lakes are filled because the controls on the process have not been widely studied or physically interpreted. Utilizing existing theory and field data from lakes of the Sacramento River, we examined the controls on oxbow alluviation by bed load and found that the transport of bed material through a channel abandoned by cutoff is highly sensitive to the orientation of the abandoned-channel entrance. In particular, the diversion angle, the angle between the approaching active- channel flow and the abandoned-channel entrance, is a direct control on discharge through the abandoned channel, and thus can significantly reduce boundary shear-stress and limit the transport capacity of bed load. The higher the angle, the more greatly reduced is the capacity to transmit bed material, and the more quickly the channel is hydraulically disconnected as diverted bed load rapidly aggrades the channel entrance. In contrast, the lower the angle, the longer the duration the channel remains hydraulically connected, and the more likely it will experience filling and narrowing by bed load because sufficient flow allows for the downstream and transverse transport of bed material. Our findings from the Sacramento River compare well to observations from other large meandering rivers and may explain why some lakes are terrestrialized within decades of cutoff, whereas others remain as open-water habitat for considerably longer.

  15. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region

    Science.gov (United States)

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

    2016-01-01

    Alluvial fans formed from sediments derived from erosion of the Juárez Mountains in northernmost México have a significant flood impact on the Ciudad Juárez, which is built on the fan system. The northern part of Ciudad Juárez is the most active; further south, older parts of the fan, upon which the rest of the city is built, were largely eroded by natural processes prior to human habitation and subsequently modified only recently by human construction. Three aeolian sand samples, collected from the uppermost (youngest) parts of the fan system in the city area, in places where human intervention has not disturbed the sediment, and constrain the latest dates of fan building. Depositional ages of the Quaternary alluvial fans were measured using Optically Stimulated Luminescence (OSL) on aeolian sands that have inter-fingered with alluvial fan material. These dates are: a) sample P1, 31 ka; b) sample P2, 41 ka; c) sample P3, 74 ka, between Oxygen Isotope Stages (OIS) 3 to 5. They demonstrate that fan development, in the area now occupied by the city, terminated in the Late Pleistocene, immediately after what we interpret to have been an extended period of erosion without further deposition, lasting from the Late Pleistocene to Holocene. The three dates broadly correspond to global glacial periods, implying that the cool, dry periods may reflect periods of aeolian transport in northern México in between phases that were wetter to form the alluvial fans. Alluvial fan margins inter-finger with fluvial terrace sediments derived from the Río Bravo, indicating an additional component of fan dissection by Río Bravo lateral erosion, presumed to be active during earlier times than our OSL ages, but these are not yet dated. Further dating is required to ascertain the controls on the fan and fluvial system.

  16. Groundwater components in the alluvial aquifer of the alpine Rhone River valley, Bois de Finges area, Wallis Canton, Switzerland

    Science.gov (United States)

    Schürch, Marc; Vuataz, François-D.

    2000-09-01

    Source, type, and quantity of various components of groundwater, as well as their spatial and temporal variations were determined by different hydrochemical methods in the alluvial aquifer of the upper Rhone River valley, Bois de Finges, Wallis Canton, Switzerland. The methods used are hydrochemical modeling, stable-isotope analysis, and chemical analysis of surface water and groundwater. Sampling during high- and low-water periods determined the spatial distribution of the water chemistry, whereas monthly sampling over three years provided a basis for understanding seasonal variability. The physico-chemical parameters of the groundwater have spatial and seasonal variations. The groundwater chemical composition of the Rhone alluvial aquifer indicates a mixing of weakly mineralized Rhone River water and SO4-rich water entering from the south side of the valley. Temporal changes in groundwater chemistry and in groundwater levels reflect the seasonal variations of the different contributors to groundwater recharge. The Rhone River recharges the alluvial aquifer only during the summer high-water period. Résumé. Origine, type et quantité de nombreux composants d'eau de l'aquifère alluvial dans la vallée supérieure du Rhône, Bois de Finges, Valais, Suisse, ainsi que leurs variations spatiales et temporelles ont été déterminés par différentes méthodes hydrochimiques. Les méthodes utilisées sont la modélisation hydrochimique, les isotopes stables, ainsi que l'échantillonnage en période de hautes eaux et de basses eaux pour étudier la distribution spatiale de la composition chimique, alors qu'un échantillonnage mensuel pendant trois ans sert à comprendre les processus de la variabilité saisonnière. Les paramètres physico-chimiques des eaux souterraines montrent des variations spatiales et saisonnières. La composition chimique de l'aquifère alluvial du Rhône indique un mélange entre une eau peu minéralisée venant du Rhône et une eau sulfatée s

  17. Degradation of 14C ring labelled pesticides in selected soils of Sri Lanka

    International Nuclear Information System (INIS)

    Ground water resources in Sri Lanka are largely derived from direct rainfall seepage and recharge from surface water bodies. Ground water contamination potential of pesticides is governed by many soil, pesticide and environmental factors. One of the critical factors that affects is the rate at which pesticides degrade in the soil. This is the process that eliminates the chemical from the environment. Therefore the knowledge of degradation rates of pesticides is essential for pollution control management. Degradation and dissipation rates of 14C ring labelled carbofuran and diazinon in selected Sri Lankan soils were studied under laboratory conditions. 0.1 Ci/10 g soil of ring labelled carbofuran and diazinon-were added to Nuwara Eliya (Red yellow podzolic), Pugoda (Alluvials) Kalpitiya and Negombo (Regosols) soils and incubated in 75% of maximum water holding capacity and 28 degree C of temperature for 13 hours light and 11 hours dark conditions. Liberated 14CO2 was collected after 0, 1, 3, 5, 7, 14, 28, 36, 42 and 58 days to an alkaline solution and analyzed using Liquid Scintillation Counter. Carbofuran has a mineralization rate of 12.5% in Kalpitiya regosols, 7.5% in Pugoda alluvials and lower rates in other two soils after 20 days. After 40 days it increases over 20% in Kalpitiya and in other three soils it was less than 15%. After-58 days the mineralization was over 60% in Kalpitiya soils but less than 500/o in other three soils. During the whole period the mineralization was less than 10% in Nuwara Eliya red yellow podzolic soils. Diazinon exhibited 25% mineralization in Nuwara Eliya and Kalpitiya soils after ten days but in Pugoda and Negombo soils it was less than 20%. After 40 days it was 80% in Kalpitiya soil and 60% in Nuwara Eliya. During the total period the mineralization is less than 25% in Negombo and Pugoda soils. Overall, the degradation rate of carbofuran is much lower than diazinon for all selected soils. Therefore the contamination risk by

  18. Vertical distribution of radiocesium in soils of the area affected by the Fukushima Dai-ichi nuclear power plant accident

    Science.gov (United States)

    Konoplev, A. V.; Golosov, V. N.; Yoschenko, V. I.; Nanba, K.; Onda, Y.; Takase, T.; Wakiyama, Y.

    2016-05-01

    Presented are results of the study of radiocesium vertical distribution in the soils of the irrigation pond catchments in the near field 0.25 to 8 km from the Fukushima Dai-ichi NPP, on sections of the Niida River floodplain, and in a forest ecosystem typical of the territory contaminated after the accident. It is shown that the vertical migration of radiocesium in undisturbed forest and grassland soils in the zone affected by the Fukushima accident is faster than it was in the soils of the 30-km zone of the Chernobyl NPP for a similar time interval after the accident. The effective dispersion coefficients in the Fukushima soils are several times higher than those for the Chernobyl soils. This may be associated with higher annual precipitation (by about 2.5 times) in Fukushima as compared to the Chernobyl zone. In the forest soils the radiocesium dispersion is faster as compared to grassland soils, both in the Fukushima and Chernobyl zones. The study and analysis of the vertical distribution of the Fukushima origin radiocesium in the Niida gawa floodplain soils has made it possible to identify areas of contaminated sediment accumulation on the floodplain. The average accumulation rate for sediments at the study locations on the Niida gawa floodplain varied from 0.3 to 3.3 cm/year. Taking into account the sediments accumulation leading to an increase in the radiocesium inventory in alluvial soils is key for predicting redistribution of radioactive contamination after the Fukushima accident on the river catchments, as well as for decision-making on contaminated territories remediation and clean-up. Clean-up of alluvial soils does not seem to be worthwhile because of the following accumulation of contaminated sediments originating from more contaminated areas, including the exclusion zone.

  19. Estabilidade temporal da potenciometria e da salinidade em vale aluvial no semiárido de Pernambuco Temporal stability of piezometric levels and salinity in an alluvial valley in the semiarid Pernambuco - Brazil

    Directory of Open Access Journals (Sweden)

    Robertson V. de P. Fontes Júnior

    2012-11-01

    Full Text Available As restrições no uso e na disponibilidade das águas subterrâneas nos aluviões do semiárido nordestino estão diretamente ligadas à sazonalidade e à variabilidade espacial de seus níveis potenciométricos e salinidade. A estabilidade temporal é de grande interesse, por facilitar o monitoramento, possibilitando se obter locais representativos acerca da área em estudo, constituindo-se em uma importante ferramenta para a gestão dos recursos hídricos subterrâneos. Com isto, o objetivo deste trabalho foi identificar áreas com estabilidade temporal do nível potenciométrico e da salinidade, em aquífero aluvial do Agreste Pernambucano. Foram utilizados o método das diferenças relativas e a validação por correlação entre a média no tempo do piezômetro estável e a média dos demais piezômetros. Quanto ao nível potenciométrico identificaram-se áreas estáveis que representam o comportamento médio enquanto para a salinidade as áreas estáveis não representam adequadamente a média do vale aluvial devido, possivelmente, às restrições de circulação hídrica e ao uso agrícola do solo.The restrictions in the use and availability of groundwater in alluvial aquifers of the northeastern semiarid are directly related to seasonal and spatial variability of piezometric levels and salinity. Temporal stability is of high interest for monitoring, allowing representative locations about the studied area to be identified, being an important tool for groundwater resources management. Thus, the objective of this work was to identify areas with temporal stability for the water table level and salinity in an alluvial aquifer in the 'Agreste' region of Pernambuco State in Brazil. The relative difference method was used and also the validation by correlation between the mean response of one stable piezometer against the mean of all other piezometers, performed in time. For the water table level, stable areas representing the mean behavior

  20. Two-dimensional numerical modeling of the longitudinal and lateral channel deformations in alluvial rivers

    Institute of Scientific and Technical Information of China (English)

    XIA Junqiang; WANG Guangqian; WU Baosheng

    2004-01-01

    Two kinds of bank erosion mechanisms were analyzed, including fluvial and non-fluvial controlled mechanisms, and mechanical methods of simulating the erosion processes of cohesive, non-cohesive and composite riverbanks were improved. Then a two-dimensional numerical model of the channel deformation was developed, consisting of a 2D flow and sediment transport submodel and bank-erosion submodels of different soil riverbanks. In the model, a new technique for updating the bank geometry during the bed evolution was presented, which combines closely two kinds of submodels. The proposed model is capable of not only predicting the processes of flood routing and longitudinal channel deformation in natural rivers, but also simulating the processes of lateral channel deformation, especially the processes of lateral erosion and failure of cohesive, non-cohesive and composite riverbanks.

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

    Science.gov (United States)

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

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

  2. Physical and water properties of selected Polish heavy soils of various origins

    Directory of Open Access Journals (Sweden)

    Kaczmarek Zbigniew

    2015-12-01

    Full Text Available The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.

  3. Dynamics of PCB removal and detoxification in historically contaminated soils amended with activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyeva, Galina K., E-mail: gkvasilyeva@issp.psn.r [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino 142290 (Russian Federation); Strijakova, Elena R. [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino 142290 (Russian Federation); Nikolaeva, Svetlana N.; Lebedev, Albert T. [Chemistry Department of Moscow State University, Moscow (Russian Federation); Shea, Patrick J. [School of Natural Resources, University of Nebraska-Lincoln (United States); Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Lincoln, NE 68583-0817 (United States)

    2010-03-15

    Activated carbon (AC) can help overcome toxicity of pollutants to microbes and facilitate soil bioremediation. We used this approach to treat a Histosol and an Alluvial soil historically contaminated with PCB (4190 and 1585 mg kg{sup -1}, respectively; primarily tri-, tetra- and pentachlorinated congeners). Results confirmed PCB persistence; reductions in PCB extractable from control and AC-amended soils were mostly due to a decrease in tri- and to some extent tetrachlorinated congeners as well as formation of a bound fraction. Mechanisms of PCB binding by soil and AC were different. In addition to microbial degradation of less chlorinated congeners, we postulate AC catalyzed dechlorination of higher chlorinated congeners. A large decrease in bioavailable PCB in AC-amended soils was demonstrated by greater clover germination and biomass. Phytotoxicity was low in treated soils but remained high in untreated soils for the duration of a 39-month experiment. These observations indicate the utility of AC for remediation of soils historically contaminated with PCB. - Activated carbon promotes remediation of soils historically contaminated with PCB.

  4. Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils.

    Science.gov (United States)

    Yu, Hailing; Gao, Qiang; Shao, Zeqiang; Ying, Anning; Sun, Yuyang; Liu, Jingwei; Mao, Wei; Zhang, Bin

    2016-01-01

    In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha(-1)) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha(-1)), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand. PMID:26992097

  5. Recalibration of a ground-water flow model of the Mississippi River Valley alluvial aquifer in Southeastern Arkansas, 1918, with simulations of hydraulic heads caused by projected ground-water withdrawals through 2049

    Science.gov (United States)

    Stanton, Gregory P.; Clark, Brian R.

    2003-01-01

    The Mississippi River Valley alluvial aquifer, encompassing parts of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee supplies an average of 5 billion gallons of water per day. However, withdrawals from the aquifer in recent years have caused considerable drawdown in the hydraulic heads in southeastern Arkansas and other areas. The effects of current ground-water withdrawals and potential future withdrawals on water availability are major concerns of water managers and users as well as the general public. A full understanding of the behavior of the aquifer under various water-use scenarios is critical for the development of viable water-management and alternative source plans. To address these concerns, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, Vicksburg District, and the Arkansas Soil and Water Conservation Commission developed and calibrated a ground-water flow model for the Mississippi River valley alluvial aquifer in southeastern Arkansas to simulate hydraulic heads caused by projected ground-water withdrawals. A previously published ground-water flow model for the alluvial aquifer in southeastern Arkansas was updated and recalibrated to reflect more current pumping stresses with additional stress periods added to bring the model forward from 1982 to 1998. The updated model was developed and calibrated with MODFLOW-2000 finite difference numerical modeling and parameter estimation software. The model was calibrated using hydraulic-head data collected during 1972 and 1982 and hydraulic-head measurements made during spring (February to April) of 1992 and 1998. The residuals for 1992 and 1998 have a mean absolute value of 4.74 and 5.45 feet, respectively, and a root mean square error of 5.9 and 6.72 feet, respectively. The effects of projected ground-water withdrawals were simulated through 2049 in three predictive scenarios by adding five additional stress periods of 10 years each. In the three scenarios

  6. Rice production in relation to soil quality under different rice-based cropping systems

    Science.gov (United States)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    soil depth without restriction for rice root elongation was at least 25 cm from the soil surface. We suggest these values as indicative for optimal physical soil quality when growing rice in fine-textured alluvial soils and their definition as a first step towards presenting real threshold values.

  7. Soils electroremediation

    International Nuclear Information System (INIS)

    This paper presents data on decontamination experiments performed with soils contaminated by long-lived radioactive caesium isotopes. The contamination was formed about 30 years ago during an accident in the first nuclear power station in the former Czechoslovakia. Because of the large soil quantities that make excavation and storage of these soils in nuclear waste repositories inconvenient from economical and spatial point of view, various methods for in situ or ex situ remediation were sought and tested. For soil contamination by caesium, the time of contact of caesium with the soil is crucial because the caesium ions diffuse inside the crystalline structures of clay minerals where they are virtually irreversibly bound. For such materials, the efficiency of the classic 'soft' decontamination methods, such as leaching, phytoremediation etc., is rather low. Electrochemical decontamination was proposed as the decontamination technique for ex situ application. The method is based on electrolysis at a relatively high current density in a suitable electrolyte. The soil is kept in suspension close to the anode, and owing to the high acidity together with both the high temperature and ion flux, the soil structures are opened or partially disrupted and caesium ions are released. The ions can be separated from the solution, e.g., by using selective ion exchangers. The experimental electrolytic cell was designed for the treatment of thin soil layers containing about 3 g of the soil and about 100 mL of electrolyte. The influence of various system parameters, such as electrolyte composition, current-voltage, temperature, and time, on the decontamination efficiency was examined. In the most efficient configuration, a 99+% decontamination level was achieved. For the next step, a bench-scale apparatus was designed that should allow treatment of batches of up to 0.5 kg of soil in one step. (author)

  8. Land use, forest density, soil mapping, erosion, drainage, salinity limitations

    Science.gov (United States)

    Yassoglou, N. J. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. The results of analyses show that it is possible to obtain information of practical significance as follows: (1) A quick and accurate estimate of the proper use of the valuable land can be made on the basis of temporal and spectral characteristics of the land features. (2) A rather accurate delineation of the major forest formations in the test areas was achieved on the basis of spatial and spectral characteristics of the studied areas. The forest stands were separated into two density classes; dense forest, and broken forest. On the basis of ERTS-1 data and the existing ground truth information a rather accurate mapping of the major vegetational forms of the mountain ranges can be made. (3) Major soil formations are mapable from ERTS-1 data: recent alluvial soils; soil on quarternary deposits; severely eroded soil and lithosol; and wet soils. (4) An estimation of cost benefits cannot be made accurately at this stage of the investigation. However, a rough estimate of the ratio of the cost for obtaining the same amount information from ERTS-1 data and from conventional operations would be approximately 1:6 to 1:10, in favor of the ERTS-1.

  9. Contrasting soils and landscapes of the Piedmont and Coastal Plain, eastern United States

    Science.gov (United States)

    Markewich, H.W.; Pavich, M.J.; Buell, G.R.

    1990-01-01

    The Piedmont and Coastal Plain physiographic provinces comprise 80 percent of the Atlantic Coastal states from New Jersey to Georgia. The provinces are climatically similar. The soil moisture regime is udic. The soil temperature regime is typically thermic from Virginia through Georgia, although it is mesic at altitudes above 400 m in Georgia and above 320 m in Virginia. The soil temperature regime is mesic for the Piedmont and Coastal Plain from Maryland through New Jersey. The tightly folded, structurally complex crystalline rocks of the Piedmont and the gently dipping "layer-cake" clastic sedimentary rocks and sediments of the Coastal Plain respond differently to weathering, pedogenesis, and erosion. The different responses result in two physiographically contrasting terrains; each has distinctive near-surface hydrology, regolith, drainage morphology, and morphometry. The Piedmont is predominantly an erosional terrain. Interfluves are as narrow as 0.5 to 2 km, and are convex upward. Valleys are as narrow as 0.1 to 0.5 km and generally V-shaped in cross section. Alluvial terraces are rare and discontinuous. Soils in the Piedmont are typically less than 1 m thick, have less sand and more clay than Coastal Plain soils, and generally have not developed sandy epipedons. Infiltration rates for Piedmont soils are low at 6-15 cm/h. The soil/saprolite, soil/rock, and saprolite/rock boundaries are distinct (can be placed within 10 cm) and are characterized by ponding and/or lateral movement of water. Water movement through soil into saprolite, and from saprolite into rock, is along joints, foliation, bedding planes and faults. Soils and isotopic data indicate residence times consistent with a Pleistocene age for most Piedmont soils. The Coastal Plain is both an erosional and a constructional terrain. Interfluves commonly are broader than 2 km and are flat. Valleys are commonly as wide as 1 km to greater than 10 km, and contain numerous alluvial and estuarine terrace

  10. 钱塘江边冲海积粉土基坑安全性数值分析%Numerical simulation of safety evaluation of alluvial silt foundation pits along Qiantang River

    Institute of Scientific and Technical Information of China (English)

    杨迎晓; 陈峰

    2014-01-01

    钱塘江流域正在开展大规模的建设,河口两岸海塘、江边基坑面临洪水、强潮的严重侵袭。选择钱塘江土海塘典型地质剖面和砼海塘典型地质剖面,考虑钱塘江粉土的剪胀性,采用Hardening-Soil本构模型,数值研究潮位及离江距离、围护墙嵌固深度、开挖深度对基坑安全性的影响,分析江边粉土基坑破坏模式。结果表明:高潮位下,土海塘典型地质剖面的江边基坑,可能出现海塘先于基坑破坏的模式;基坑开挖深度较小时,支护结构整体向坑内倾倒破坏;基坑开挖深度较大,呈踢脚破坏模式。坑底边旁在距围护墙的嵌固深度一半范围内,容易发生流土破坏。%Large-scale construction is being conducted along the Qiantang River. However, the foundation pits along the river are threatened by floods and strong tides. Typical geological cross sections of the soil seawalls and concrete seawalls along the river are selected for this study, and the dilatant characteristics of silt are taken into account. Numerical simulations based on the hardening-soil model are carried out to study the effects of the river tidal level, pit-river distance, insertion depth of enclosure walls and pit excavation depth on the safety of the alluvial silt foundation pits. The results demonstrate that under high tidal levels the pits with cross sections of soil seawalls will probably display a mode in which the destruction of seawalls occurs before the destruction of the pits. Moreover, the support and protection structures will fall down into the pit as a whole when the pit evacuation depth is small. When the pit evacuation depth is large, however, the support and protection structures will display a kicking destruction mode. Additionally,the flowing-soil destruction is found to occur most easily when the pit bottom is within half the insertion depth of enclosure walls.

  11. Effects of Different Soil Amendments on Transformation of Exogenetic Cd Forms in Soil%改良剂对土壤中外源镉形态转化的影响研究

    Institute of Scientific and Technical Information of China (English)

    邵丽群; 王翠红; 何明远

    2011-01-01

    The effects of four different soil amendments (white lime, Ca+Mg+P fertilizer, white lime+cow dung and dried and molar Astragalus sinicus L.) on transformation of Cd forms in alluvial soil and quaternary red soil were studied by using incubation experiment. The results showed that these four soil amendments can obviously reduce the content of exchange Cd in 30 d cultured alluvial soil and quaternary red soil, promote the Cd form in soil gradually changing from exchange Cd form to Fe-Mn oxidation state, organic combination state, carbonate bounded form and residual form. Therefore, white lime, Ca+Mg+P fertilizer, while lime+cow dung and dried and molar Astragalus sinicus L. All can be effective soil amendment for in situ repairing Cd polluted soil.%采用室内培养试验,研究了4种不同改良剂(熟石灰、熟石灰+牛粪、钙镁磷肥、烘干磨碎的紫云英)对河潮土、第四纪红土红壤中镉(Cd)形态转化的影响.结果表明,4种改良剂可明显降低培养30 d后河潮土、第四纪红土中可交换态Cd含量,促进土壤中的Cd形志逐步由可交换态Cd向Fe-Mn氧化态、有机结合态、碳酸盐结合态.残渣态转化.因此,熟石灰、熟石灰+牛粪、钙镁磷肥、紫云英均可作为有效的原位修复Cd污染的上壤改良剂.

  12. Assessing soil hydraulic characteristics using HYPROP and BEST: a comparison

    Science.gov (United States)

    Leitinger, Georg; Obojes, Nikolaus; Lassabatère, Laurent

    2015-04-01

    Knowledge of ecohydrological characteristics with high spatial resolution is a prerequisite for large-scale hydrological modelling. Data on soil hydraulic characteristics are of major importance, but measurements are often seen as time consuming and costly. In order to accurately model grassland productivity and in particular evapotranspiration, soil sampling and infiltration experiments at 25 grassland sites ranging from 900m to 2300m a.s.l. were conducted in the long term socio-ecological research (LTSER) site Stubai Valley, Tyrolean Alps, Austria, covering 265 km². Here we present a comparison of two methods to determine important hydrological properties of soils: (1) the evaporation method HYPROP (Hydraulic Property Analyzer; UMS Munich, 2010), and (2) the BEST-model (Beerkan Estimation of Soil Transfer Parameters; Lassabatère et al. (2006)), each determining the soil hydraulic characteristics and in particular the water retention curve. For the most abundant soil types we compared the pf-curves calculated from HYPROP data suing the Van Genuchten equation to the ones resulting from the comparatively time efficient BEST approach to find out if the latter is a suitable method to determine pf curves of alpine grassland soils. Except for the soil type Rendzina, the comparison of HYPROP and BEST showed slightly variations in the pF curves and resulting hydraulic characteristics. At the starting point BEST curves presented a slower dehydration, HYPROP a fast and continuous water loss. HYPROP analyses showed the highest variability in the measured values of Rendzina. Regarding BEST, the Alluvial Soils showed the highest variability. To assess equivalence between HYPROP and BEST we deduced several hydraulic characteristics from the pF curves, e.g. saturated water content, field capacity, permanent wilting point, pore size distribution, and minimum water retention. The comparison of HYPROP and BEST revealed that the results of soil water characteristics may depend on

  13. The migration, dissolution, and fate of chlorinated solvents in the urbanized alluvial valleys of the southwestern USA

    Science.gov (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

  14. Soil mechanics

    Science.gov (United States)

    Mitchell, J. K.; Carrier, W. D., III; Houston, W. N.; Scott, R. F.; Bromwell, L. G.; Durgunoglu, H. T.; Hovland, H. J.; Treadwell, D. D.; Costes, N. C.

    1972-01-01

    Preliminary results are presented of an investigation of the physical and mechanical properties of lunar soil on the Descartes slopes, and the Cayley Plains in the vicinity of the LM for Apollo 16. The soil mechanics data were derived form (1) crew commentary and debriefings, (2) television, (3) lunar surface photography, (4) performance data and observations of interactions between soil and lunar roving vehicle, (5) drive-tube and deep drill samples, (6) sample characteristics, and (7) measurements using the SRP. The general characteristics, stratigraphy and variability are described along with the core samples, penetrometer test results, density, porosity and strength.

  15. Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica.

    OpenAIRE

    Van NIEUWENHUYSE, A.

    1996-01-01

    The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern side it is bordered by active volcanoes. The climate of the area is hot and humid throughout the year, with a constant mean air temperature of about 25°C and a welldistributed mean annual rainfall of about 350...

  16. Nitrate leaching from short-hydroperiod floodplain soils

    Directory of Open Access Journals (Sweden)

    B. Huber

    2012-05-01

    Full Text Available Numerous studies have shown the importance of riparian zones to reduce nitrate (NO3 contamination coming from adjacent agricultural land. Much less is known about nitrogen (N transformations and nitrate fluxes in riparian soils with short hydroperiods (1–3 days of inundation and there is no study that could show whether these soils are a N sink or source.

    Within a restored section of the Thur River in NE Switzerland, we measured nitrate concentrations in soil solutions as an indicator of the net nitrate production. Samples were collected along a quasi-successional gradient from frequently inundated gravel bars to an alluvial forest, at three different depths (10, 50 and 100 cm over a one-year period. Along this gradient we quantified N input (atmospheric deposition and sedimentation and N output (leaching to create a nitrogen balance and assess the risk of nitrate leaching from the unsaturated soil to the groundwater.

    Overall, the main factor explaining the differences in nitrate concentrations was the variability in soil texture and volumetric water content (VWC at field capacity (FC. In subsoils with high VWC at FC and VWC near 100 % FC, high nitrate concentrations were observed, often exceeding the Swiss and EU groundwater quality criterions of 400 and 800 μmol l−1, respectively. High sedimentation rates of river-derived nitrogen led to apparent N retention up to 200 kg N ha−1 yr−1 in the frequently inundated zones. By contrast, in the mature alluvial forest, nitrate leaching exceeded total N input most of the time. As a result of the large soil N pools, high amounts of nitrate were produced by nitrification and up to 94 kg N-NO3 ha−1 yr−1 were leached into the groundwater. Thus, during flooding when water fluxes are high, nitrate from soils can contribute up to 11 % to the total nitrate load in groundwater.

  17. Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, B.D.; Mahan, S.A.

    1994-12-31

    The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infilling in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from weathering of silicate detritus. However, calcretes from a fan draining a carbonate terrane have strontium compositions dominated locally by the limestone strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system.

  18. Efficiency of ammonium nitrate phosphates of varying water-soluble phosphorous content for wheat and succeeding maize crop on different soil types

    International Nuclear Information System (INIS)

    Efficiency of 32P labelled ammonium nitrate phosphate (ANP) containding 30, 50 and 90 per cent of water-soluble phosphorus (WSP) vis-a-vis that of entirely water soluble monoammonium orthophosphate (MAP) for wheat and succeeding maize crop on deep black (vertisol), calcareous black (vertisol), alluvial-Tarai (mollisol) and grey brown alluvial (aridisol) soils was examined in greenhouse experiments. Data on wheat indicated that ANP (50 per cent WSP) was, in general, equally efficient to MAP and ANP (90 per cent WSP) in terms of drymatter yield and total uptake of phosphorus in all soils examined, however, the per cent utilization of applied fertilizer was significantly higher for MAP and ANP (90 per cent WSP) than those for ANP (50 per cent WSP) in all soils. In general, ANP (30 per cent WSP) was significantly inferior to MAP and ANP (90 per cent WSP) in all soils. Data on the succeeding maize crop grown to flowering indicated that residual value of ANP (30 per cent WSP) was equal to that of MAP and ANP (90 per cent WSP) in terms of drymatter yield and phosphorus uptake by the four soils examined. Complementary incubation studies conducted upto 60 days on the above four soils at field capacity moisture status indicated highest 0.5 M NaHCO3 (pH 8.5) extractable phosphorus levels in MAP treatments followed by ANP (50 per cent WSP) and least in ANP (30 per cent WSP) treatments. (author). 4 tables, 4 figures, 19 refs

  19. Alluvial deposition and lake-level fluctuations forced by Late Quaternary climate change: the Dead Sea case example

    Science.gov (United States)

    Klinger, Y.; Avouac, J. P.; Bourles, D.; Tisnerat, N.

    2003-11-01

    Based on geomorphic observations, we discuss lake-level fluctuations, alluvial deposition and river entrenchment in the Dead Sea-Wadi Araba area. The bulk of alluvium in the northern Wadi Araba was probably deposited before the Lisan period of lake transgression that started at about 70 kyears B.P. The lake reached a maximum elevation about 150 m below sea level (b.s.l.), possibly around 15 cal. kyears B.P. as indicated by the highest preserved beach ridges. Cosmogenic exposure dates show that the ridge material consists mainly of remobilized Pleistocene gravel indicating little sediment supply during most of the Lisan period. During this period, a reduced sediment flux fed subaquatic fan deltas along the margin of the Dead Sea. Wetter conditions settled at the end of this period, the water level rose to about 280 m b.s.l. around 15 kyears B.P. and prevailed in the early Holocene (10.5-7 cal. kyears B.P.). Following that humid period, the lake level dropped and two major episodes of fluvial aggradation occurred during periods of relative low lake level. The first aggradational episode took place between about 7.0 and 6.2 cal. kyears B.P. Beach bars indicate a subsequent lake transgression between 6.2 and 4.4 kyears B.P. up to 350 m b.s.l. The second aggradational episode happened between 4.4 and 2.0 cal. kyears B.P., and was also followed by a late transgression up to 375 m b.s.l., dated to 1960-1715 cal. years B.P. The correlation between low lake level and fluvial aggradation is taken to reflect the synchronous change of the fluvial regime and of the lake hydrologic balance, forced by climate changes, rather than a base-level control. We also exclude large tectonic forcing on fan emplacement and river entrenchment. Alluviation appears in this setting as a very irregular process, characterized by long periods of quiescence alternating with periods of fan build-up, reflecting the transient response of the water drainage system to climate change.

  20. Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system

    Science.gov (United States)

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

    2013-01-01

    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

  1. Tapping the Late Pleistocene-Holocene environmental change and alluvial geoarchaeology in Central Asia

    Science.gov (United States)

    Macklin, Mark; Panyushkina, Irina; Toonen, Willem; Chang, Claudia; Seitkaliyev, Meyram; Voyakin, Dmitry

    2015-04-01

    We integrate the environmental history derived from spatial-temporal variability of multi proxies and the prehistory of arid lands from archaeological data in Central Asia in order to determine the relationship between the Holocene river dynamics, climate change and floodwater farming. This study addresses to developing fluvial achieves and geoarcheological records from the Talgar catchment, a south-bank tributary of the Ili River and the Talas catchment, a east-bank tributary of the Syr Darya River, in the southern Kazakhstan. The catchments of these steppe rivers flowing northwest had favorable habitats for farming from the Eneolithic to the medieval period as appears from human settlement histories documented with archaeological surveys and in some cases excavations. The river development has been reconstructed over the last 20,000 years and the key archaeological sites have been dated with radiocarbon. Periods of Holocene river aggradation and high water in downstream Lake Balkhash and Aral Sea correspond with cooler and wetter neoglacial episodes while river entrenchment and floodplain soil development are associated with warmer and drier conditions. Floodwater farming in the Talgar River reached its height in the late Iron Age (400-200 cal. BC) with more than 70 settlement sites and 700 burial mounds, and in the Talas River during the medieval period. This corresponds to a period of reduced flood flows, river stability and glacier retreat in the Tien Shan headwaters. A new hydroclimatic-based model for the spatial and temporal dynamics of floodwater farming is proposed, which explains settlement patterns since the first documented use of irrigation in the Iron Age and medieval times. The undertaken research highlights the Holocene human adaptations to the environmental change of floodplains in Central Asia.

  2. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake...

  3. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the Quaternary alluvial and terrace deposits along the Beaver-North Canadian River from the...

  4. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula...

  5. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital hydraulic conductivity values for the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to...

  6. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the Beaver-North Canadian River from the...

  7. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in...

  8. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant hydraulic conductivity value for the alluvial and terrace deposits along the North Canadian River from...

  9. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to...

  10. 1:1,000,000-scale estimated outer extent of areas of groundwater discharge as evapotranspiration for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a...

  11. Subsurface Biogeochemical Heterogeneity (Field-scale removal of U(VI) from groundwater in an alluvial aquifer by electron donor amendment)

    Energy Technology Data Exchange (ETDEWEB)

    Long, Philip E.; Lovley, Derek R.; N' Guessan, A. L.; Nevin, Kelly; Resch, C. T.; Arntzen, Evan; Druhan, Jenny; Peacock, Aaron; Baldwin, Brett; Dayvault, Dick; Holmes, Dawn; Williams, Ken; Hubbard, Susan; Yabusaki, Steve; Fang, Yilin; White, D. C.; Komlos, John; Jaffe, Peter

    2006-06-01

    Determine if biostimulation of alluvial aquifers by electron donor amendment can effectively remove U(VI) from groundwater at the field scale. Uranium contamination in groundwater is a significant problem at several DOE sites. In this project, the possibility of accelerating bioreduction of U(VI) to U(IV) as a means of decreasing U(VI) concentrations in groundwater is directly addressed by conducting a series of field-scale experiments. Scientific goals include demonstrating the quantitative linkage between microbial activity and U loss from groundwater and relating the dominant terminal electron accepting processes to the rate of U loss. The project is currently focused on understanding the mechanisms for unexpected long-term ({approx}2 years) removal of U after stopping electron donor amendment. Results obtained in the project successfully position DOE and others to apply biostimulation broadly to U contamination in alluvial aquifers.

  12. Modelling soil erosion risk based on RUSLE-3D using GIS in a Shivalik sub-watershed

    Indian Academy of Sciences (India)

    Suresh Kumar; S P S Kushwaha

    2013-04-01

    The RUSLE-3D (Revised Universal Soil Loss Equation-3D) model was implemented in geographic information system (GIS) for predicting the soil loss and the spatial patterns of soil erosion risk required for soil conservation planning. High resolution remote sensing data (IKONOS and IRS LISS-IV) were used to prepare land use/land cover and soil maps to derive the vegetation cover and the soil erodibility factor whereas Digital Elevation Model (DEM) was used to generate spatial topographic factor. Soil erodibility (K) factor in the sub-watershed ranged from 0.30 to 0.48. The sub-watershed is dominated by natural forest in the hilly landform and agricultural land in the piedmont and alluvial plains. Average soil loss was predicted to be lowest in very dense forest and highest in the open forest in the hilly landform. Agricultural land-1 and agriculture land-2 to have moderately high and low soil erosion risk, respectively. The study predicted that 15% area has ‘moderate’ to ‘moderately high’ and 26% area has high to very high risk of soil erosion in the sub-watershed.

  13. Hydrogeochemistry and quality assessment of shallow groundwater in the southern part of the yellow river alluvial plain (zhongwei section), northwest china

    OpenAIRE

    Li, Peiyue; Wu, Jianhua; Qian, Hui

    2014-01-01

    Statistical analyses, a Piper diagram, the saturation index and the correlations of chemical parameters were used to reveal the hydrogeochemistry and hydrogeochemical evolution of shallow groundwater in the southern part of the Zhongwei section of the Yellow River alluvial plain. The water quality for agricultural and domestic uses was also assessed in the study. The results suggest that the shallow groundwater in the study area is fresh to moderately mineralized water. Higher Ca2+ and HCO3- ...

  14. The effect of increasing salinity and forest mortality on soil nitrogen and phosphorus mineralization in tidal freshwater forested wetlands

    Science.gov (United States)

    Noe, Gregory B.; Krauss, Ken W.; Lockaby, B. Graeme; Conner, William H.; Hupp, Cliff R.

    2013-01-01

    Tidal freshwater wetlands are sensitive to sea level rise and increased salinity, although little information is known about the impact of salinification on nutrient biogeochemistry in tidal freshwater forested wetlands. We quantified soil nitrogen (N) and phosphorus (P) mineralization using seasonal in situ incubations of modified resin cores along spatial gradients of chronic salinification (from continuously freshwater tidal forest to salt impacted tidal forest to oligohaline marsh) and in hummocks and hollows of the continuously freshwater tidal forest along the blackwater Waccamaw River and alluvial Savannah River. Salinification increased rates of net N and P mineralization fluxes and turnover in tidal freshwater forested wetland soils, most likely through tree stress and senescence (for N) and conversion to oligohaline marsh (for P). Stimulation of N and P mineralization by chronic salinification was apparently unrelated to inputs of sulfate (for N and P) or direct effects of increased soil conductivity (for N). In addition, the tidal wetland soils of the alluvial river mineralized more P relative to N than the blackwater river. Finally, hummocks had much greater nitrification fluxes than hollows at the continuously freshwater tidal forested wetland sites. These findings add to knowledge of the responses of tidal freshwater ecosystems to sea level rise and salinification that is necessary to predict the consequences of state changes in coastal ecosystem structure and function due to global change, including potential impacts on estuarine eutrophication.

  15. 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

    Directory of Open Access Journals (Sweden)

    Majkić-Dursun Brankica

    2015-01-01

    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

  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

    Science.gov (United States)

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

    2007-08-01

    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. Impacts of Human Activities on the Occurrence of Groundwater Nitrate in an Alluvial Plain: A Multiple Isotopic Tracers Approach

    Institute of Scientific and Technical Information of China (English)

    Zhonghe Pang; Lijuan Yuan; Tianming Huang; Yanlong Kong; Jilai Liu; Yiman Li

    2013-01-01

    Nitrate pollution is a severe problem in areas with intensive agricultural activities.This study focuses on nitrate occurrence and its constraints in a selected alluvial fan using chemical data combined with environmental isotopic tracers (18O,3H,and 15N).Results show that groundwater nitrate in the study area is as high as 258.0 mg/L (hereafter NO3-) with an average of 86.8 mg/L against national drinking water limit of 45 mg/L and a regional baseline value of 14.4 mg/L.Outside of the riparian zone,nitrate occurrence is closely related to groundwater circulation and application of chemical fertilizer.High groundwater nitrate is found in the recharge area,where nitrate enters into groundwater through vertical infiltration,corresponding to high 3H and enriched 18O in the water.In the riparian zone,on the contrary,the fate of groundwater nitrate is strongly affected by groundwater level.Based on two sampling transects perpendicular to the riverbank,we found that the high level of nitrate corresponds to the deeper water table (25 m) near the urban center,where groundwater is heavily extracted.Groundwater nitrate is much lower (<12.4 mg/L) at localities with a shallow water table (5 m),which is likely caused by denitrification in the aquifer.

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

    Science.gov (United States)

    Sahu, Sudarsan; Saha, Dipankar

    2014-08-01

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

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

    Indian Academy of Sciences (India)

    Sudarsan Sahu; Dipankar Saha

    2014-08-01

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

  20. Groundwater response to serial stream stage fluctuations in shallow unconfined alluvial aquifers along a regulated stream (West Virginia, USA)

    Science.gov (United States)

    Maharjan, Madan; Donovan, Joseph J.

    2016-07-01

    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.

  1. Dissolved and solid-phase arsenic fate in an arsenic-enriched aquifer in the river Brahmaputra alluvial plain.

    Science.gov (United States)

    Baviskar, Shirishkumar; Choudhury, Runti; Mahanta, Chandan

    2015-03-01

    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. PMID:25663398

  2. Applicability of Artificial Recharge of Groundwater in the Yongding River Alluvial Fan in Beijing through Numerical Simulation

    Institute of Scientific and Technical Information of China (English)

    Qichen Hao; Jingli Shao; Yali Cui; Zhenhua Xie

    2014-01-01

    A groundwater transient flow model was developed to evaluate the applicability and ef-fectiveness of artificial recharge scenarios in the middle-upper part of the Yongding River alluvial fan in Beijing. These scenarios were designed by taking into account different types of recharge facilities and their infiltration rate with the Middle Route Project for South-to-North Water Transfer (MRP) as the recharge water source. The simulation results suggest that: (1) the maximum amount of artificial recharge water, for scenario I, would be 127.42×106 m3 with surface infiltration facilities;and would be 243.48×106 m3 for scenario II with surface infiltration and recharge wells under the constraint of the upper limit of groundwater;(2) with preferred pattern of recharge facilities, groundwater levels in both optimized recharge scenarios would not exceed the upper limit within the given recharge period;and (3) implementation of the recharge scenarios would efficiently increase the aquifer replenishment and the groundwater budget will change from-54.11×106 to 70.89×104 and 183.36×104 m3, respectively. In addi-tion, under these two scenarios groundwater level would rise up to 30 and 34 m, respectively, without increasing the amount of evaporation. The simulation results indicate that the proposed recharge sce-narios are practically feasible, and artificial recharge can also contribute to an efficient recovery of groundwater storage in Beijing.

  3. Characteristics of the contents and distribution of heavy metals of holocene alluvial sediments on the Nobi Plain, Central Japan

    International Nuclear Information System (INIS)

    To elucidate the background value and distribution of natural heavy metals in Holocene alluvial sediments, we examined the heavy metal contents (MnO, Fe2O3, Ni, Cu, and Zn) of five sediment cores drilled at various locations on the Nobi Plain, central Japan using an XRF analysis. The amounts of heavy metals were in proportion both to the amounts of clay fraction and Al2O3 contents of sediments. Ni, Cu, and Zn contents were higher in the clay mineral fraction than in the other fraction when applying the elutriation method. This suggests that Ni, Cu, and Zn are adsorbed onto the clay minerals. MnO was especially enriched in several horizons. This might be affected by its oxidized-reduced state. In addition, there is little difference in the heavy metal contents of terrestrial and marine sediments. Most of the heavy metal contents of samples studied were lower than those of the modern riverbed sediments from Imai et al., (2004). High concentrations of Cu were observed in subsurface sediment. These anomalous high concentrations of Cu are presumably due mainly to anthropogenic pollutions. (author)

  4. Organic matter and modeling redox reactions during river bank filtration in an alluvial aquifer of the Lot River, France.

    Science.gov (United States)

    Kedziorek, Monika A M; Geoffriau, Stephane; Bourg, Alain C M

    2008-04-15

    A 3 year study of the infiltration of Lot River water into a well field located in an adjacent gravel and clay alluvial aquifer was conducted to assess the importance of organic matter regarding the redox processes which influence groundwater quality in a positive (denitrification) or negative (Mn dissolution) manner. Chloride was used to quantify the mixing of river water with groundwater. According to modeling with PHREEQC, the biodegradation of the infiltrated dissolved organic carbon (DOCi) is not sufficient to explain the observed consequences of the redox reactions (dissolved O2 depletion, denitrification, Mn dissolution). Another electron donor source must therefore be involved: we propose solid organic carbon (SOC) as a likely candidate, if made available for degradation by prior hydrolysis. Its contribution to redox reactions could be significant (30-80% of the total organic carbon consumed by redox reactions during river bank filtration). We show here also that even though the first few meters of infiltration are highly reactive, significant redox reactions can take place further in the aquifer, possibly affecting groundwater quality away from the river bank.

  5. Nitrate leaching from short-hydroperiod floodplain soils

    Directory of Open Access Journals (Sweden)

    B. Huber

    2012-11-01

    Full Text Available Numerous studies have shown the importance of riparian zones to reduce nitrate (NO3 contamination coming from adjacent agricultural land. Much less is known about nitrogen (N transformations and nitrate fluxes in riparian soils with short hydroperiods (1–3 days of inundation and there is no study that could show whether these soils are a N sink or source. Within a restored section of the Thur River in NE Switzerland, we measured nitrate concentrations in soil solutions as an indicator of the net nitrate production. Samples were collected along a quasi-successional gradient from frequently inundated gravel bars to an alluvial forest, at three different depths (10, 50 and 100 cm over a one-year period. Along this gradient we quantified N input (atmospheric deposition and sedimentation and N output (leaching to create a nitrogen balance and assess the risk of nitrate leaching from the unsaturated soil to the groundwater. Overall, the main factor explaining the differences in nitrate concentrations was the field capacity (FC. In subsoils with high FCs and VWC near FC, high nitrate concentrations were observed, often exceeding the Swiss and EU groundwater quality criterions of 400 and 800 μmol L−1, respectively. High sedimentation rates of river-derived nitrogen led to apparent N retention up to 200 kg N ha−1 yr−1 in the frequently inundated zones. By contrast, in the mature alluvial forest, nitrate leaching exceeded total N input most of the time. As a result of the large soil N pools, high amounts of nitrate were produced by nitrification and up to 94 kg N-NO3 ha−1 yr−1 were leached into the groundwater. Thus, during flooding when water fluxes are high, nitrate from soils can contribute up to 11% to the total nitrate load in groundwater.

  6. Mid-Eocene alluvial-lacustrine succession at Gebel El-Goza El-Hamra (Shabrawet area, NE Eastern Desert, Egypt): Facies analysis, sequence stratigraphy and paleoclimatic implications

    Science.gov (United States)

    Wanas, H. A.; Sallam, E.; Zobaa, M. K.; Li, X.

    2015-11-01

    This study aims to provide the depositional facies, sequence stratigraphic and paleoclimatic characteristics of the Mid-Eocene (Bartonian) continental succession exposed at Gebel El-Goza El-Hamra (Shabrawet Area, NE Eastern Desert, Egypt). The studied succession consists of siliciclastic rocks followed upward by carbonate rocks. Detailed field observation and petrographic investigation indicate accumulation in floodplain-dominated alluvial and shallow lacustrine systems. The floodplain-dominated alluvial facies (45 m thick) is composed mainly of carbonate nodules-bearing, mottled mudrock with subordinate sandstone and conglomerate beds. The conglomerate and pebbly sandstone bodies interpreted as ephemeral braided channel deposits. The massive, laminated, planner cross-bedded, fine- to medium-grained sandstone bodies interlayered within mudstone reflect sheet flood deposits. The mudrocks associated with paleosols represent distal floodplain deposits. The shallow lacustrine facies (15 m thick) is made up of an alternation of marlstone, micritic limestone, dolostone and mudrock beds with charophytes and small gastropods. Both the alluvial and lacustrine facies show evidence of macro-and micro-pedogenic features. Pollen assemblages, stable δ18O and δ13C isotopes, and paleopedogenic features reflect prevalence of arid to semi-arid climatic conditions during the Bartonian. The sequence stratigraphic framework shows an overall fining-upward depositional sequence, consisting of Low- and High-accommodation Systems Tracts (LAST, HAST), and is bounded by two sequence boundaries (SB-1, SB-2). Conglomerate and pebbly sandstone deposits (braided channel and sheet flood deposits) of the lower part of the alluvial facies reflect a LAST. Mudrock and silty claystone facies (distal floodplain deposits) of the upper part of alluvial facies and its overlying lacustrine facies correspond to a HAST. The LAST, HAST and SB were formed during different accommodation-to-sediment supply (A

  7. Soil-aquifer phenomena affecting groundwater under vertisols: a review

    Science.gov (United States)

    Kurtzman, D.; Baram, S.; Dahan, O.

    2016-01-01

    Vertisols are cracking clayey soils that (i) usually form in alluvial lowlands where, normally, groundwater pools into aquifers; (ii) have different types of voids (due to cracking), which make flow and transport of water, solutes and gas complex; and (iii) are regarded as fertile soils in many areas. The combination of these characteristics results in the unique soil-aquifer phenomena that are highlighted and summarized in this review. The review is divided into the following four sections: (1) soil cracks as preferential pathways for water and contaminants: in this section lysimeter-to basin-scale observations that show the significance of cracks as preferential-flow paths in vertisols, which bypass matrix blocks in the unsaturated zone, are summarized. Relatively fresh-water recharge and groundwater contamination from these fluxes and their modeling are reviewed; (2) soil cracks as deep evaporators and unsaturated-zone salinity: deep sediment samples under uncultivated vertisols in semiarid regions reveal a dry (immobile), saline matrix, partly due to enhanced evaporation through soil cracks. Observations of this phenomenon are compiled in this section and the mechanism of evapoconcentration due to air flow in the cracks is discussed; (3) impact of cultivation on flushing of the unsaturated zone and aquifer salinization: the third section examines studies reporting that land-use change of vertisols from native land to cropland promotes greater fluxes through the saline unsaturated-zone matrix, eventually flushing salts to the aquifer. Different degrees of salt flushing are assessed as well as aquifer salinization on different scales, and a comparison is made with aquifers under other soils; (4) relatively little nitrate contamination in aquifers under vertisols: in this section we turn the light on observations showing that aquifers under cultivated vertisols are somewhat resistant to groundwater contamination by nitrate (the major agriculturally related

  8. Effect of the soil type on the microbiome in the rhizosphere of field-grown lettuce

    Directory of Open Access Journals (Sweden)

    Susanne eSchreiter

    2014-04-01

    Full Text Available The complex and enormous diversity of microorganisms associated with plant roots is important for plant health and growth and is shaped by numerous factors. This study aimed to unravel the effects of the soil type on bacterial communities in the rhizosphere of field-grown lettuce. We used an experimental plot system with three different soil types that were stored at the same site for ten years under the same agricultural management to reveal differences directly linked to the soil type and not influenced by other factors such as climate or cropping history. Bulk soil and rhizosphere samples were collected three and seven weeks after planting. The analysis of 16S rRNA gene fragments amplified from total community DNA by denaturing gradient gel electrophoresis and pyrosequencing revealed soil type-dependent differences in the bacterial community structure of the bulk soils and the corresponding rhizospheres. The rhizosphere effect differed depending on the soil type and the plant growth developmental stage. Despite the soil type-dependent differences in the bacterial community composition several genera such as Sphingomonas, Rhizobium, Pseudomonas and Variovorax were significantly increased in the rhizosphere of lettuce grown in all three different soils. The number of rhizosphere responders was highest three weeks after planting. Interestingly, in the soil with the highest numbers of responders the highest shoot dry weights were observed. Heatmap analysis revealed that many dominant operational taxonomic units were shared among rhizosphere samples of lettuce grown in diluvial sand, alluvial loam, and loess loam and that only a subset was increased in relative abundance in the rhizosphere compared to the corresponding bulk soil. The findings of the study provide insights into the effect of soil types on the rhizosphere microbiome of lettuce.

  9. Evaluating the reliability of Late Quaternary landform ages: Integrating 10Be cosmogenic surface exposure dating with U-series dating of pedogenic carbonate on alluvial and fluvial deposits, Sonoran desert, California

    Science.gov (United States)

    Blisniuk, K.; Sharp, W. D.

    2015-12-01

    To assess the reliability of Quaternary age determinations of alluvial and fluvial deposits across the Sonoran Desert (Coachella Valley and Anza Borrego) in southern California, we applied both 10Be exposure age dating of surface clasts and U-series dating of pedogenic carbonate from subsurface clast-coatings to the same deposits. We consider agreement between dates from the two techniques to indicate reliable age estimates because each technique is subject to distinct assumptions and therefore their systematic uncertainties are largely independent. 10Be exposure dates should yield maximum ages when no correction is made for inheritance and post-depositional erosion is negligible. U-series dating, in contrast, provides minimum dates because pedogenic carbonate forms after deposition. Our results show that: (1) For deposits ca. 70 ka or younger, 10Be and U-series dates were generally concordant. We note, however, that in most cases U-series soil dates exceed 10Be exposure dates that are corrected for inheritance when using 10Be in modern alluvium. This suggests that 10Be concentrations of modern alluvium may exceed the 10Be acquired by late Pleistocene deposits during fluvial transport and hillslope residence (i.e., Pleistocene inherited 10Be). (2) For deposits older than ~70 ka, U-series dates are significantly younger than the 10Be dates. This implies that U-series dates in this region may significantly underestimate the depositional age of older alluvium, probably because of delayed onset of deposition, slow accumulation, or poor preservation of secondary carbonate in response to climatic controls. Thus, whenever possible, multiple dating methods should be applied to obtain reliable ages for late Quaternary deposits.

  10. Hydrogeology and water quality in the Snake River alluvial aquifer at Jackson Hole Airport, Jackson, Wyoming, water years 2011 and 2012

    Science.gov (United States)

    Wright, Peter R.

    2013-01-01

    The hydrogeology and water quality of the Snake River alluvial aquifer at the Jackson Hole Airport in northwest Wyoming was studied by the U.S. Geological Survey, in cooperation with the Jackson Hole Airport Board, during water years 2011 and 2012 as part of a followup to a previous baseline study during September 2008 through June 2009. Hydrogeologic conditions were characterized using data collected from 19 Jackson Hole Airport wells. Groundwater levels are summarized in this report and the direction of groundwater flow, hydraulic gradients, and estimated groundwater velocity rates in the Snake River alluvial aquifer underlying the study area are presented. Analytical results of groundwater samples collected from 10 wells during water years 2011 and 2012 are presented and summarized. The water table at Jackson Hole Airport was lowest in early spring and reached its peak in July or August, with an increase of 12.5 to 15.5 feet between April and July 2011. Groundwater flow was predominantly horizontal but generally had the hydraulic potential for downward flow. Groundwater flow within the Snake River alluvial aquifer at the airport was from the northeast to the west-southwest, with horizontal velocities estimated to be about 25 to 68 feet per day. This range of velocities slightly is broader than the range determined in the previous study and likely is due to variability in the local climate. The travel time from the farthest upgradient well to the farthest downgradient well was approximately 52 to 142 days. This estimate only describes the average movement of groundwater, and some solutes may move at a different rate than groundwater through the aquifer. The quality of the water in the alluvial aquifer generally was considered good. Water from the alluvial aquifer was fresh, hard to very hard, and dominated by calcium carbonate. No constituents were detected at concentrations exceeding U.S. Environmental Protection Agency maximum contaminant levels or health

  11. Soil Survey Geographic (SSURGO) - Magnesic Soils

    Data.gov (United States)

    California Department of Resources — Magnesic soils is a subset of the SSURGO dataset containing soil family selected based on the magnesic content and serpentinite parent material. The following soil...

  12. Polychlorinated naphthalenes in urban soils: analysis, concentrations, and relation to other persistent organic pollutants

    International Nuclear Information System (INIS)

    Some of the first data on polychlorinated naphthalenes (PCNs) in soils are presented from a rural-urban-industrial gradient. - We determined the concentrations of 35 PCNs, 12 PCBs, and 20 PAHs in 49 urban topsoils under different land use (house garden, roadside grassland, alluvial grassland, park areas, industrial sites, agricultural sites) and in nine rural topsoils. The sums of concentrations of 35 PCNs (Σ35 PCNs) were -1 in urban soils and -1 in rural soils. The PCN, PCB, and PAH concentrations were highest at industrial sites and in house gardens. While rural soils receive PCNs, PCBs, and PAHs by common atmospheric deposition, there are site-specific sources of PCNs, PCBs, and PAHs for urban soils such as deposition of contaminated technogenic materials. The PCN, PCB, and PAH concentrations decreased from the central urban to the rural area. In the same order the contribution of lower chlorinated PCNs and PCBs increased because they are more volatile and subject to increased atmospheric transport. The PCNs 52+60, and 73 were more abundant in soil samples than in Halowax mixtures, indicating that combustion contributed to the PCN contamination of the soils

  13. Schoolground Soil Studies.

    Science.gov (United States)

    Doyle, Charles

    1978-01-01

    Outlined are simple activities for studying soil, which can be conducted in the schoolyard. Concepts include soil profiles, topsoil, soil sizes, making soil, erosion, slope, and water absorption. (SJL)

  14. Remontant erosion in desert soils of Tamaulipas, México.

    Science.gov (United States)

    Rivera-Ortiz, P.; Andrade-Limas, E.; De la Garza-Requena, F.; Castro-Meza, B.

    2012-04-01

    REMONTANT EROSION IN DESERT SOILS OF TAMAULIPAS MÉXICO Rivera-Ortiz, P.1; Andrade-Limas, E.1; De la Garza-Requena, F.1 and Castro-Meza, B.1 1Facultad de Ingeniería y Ciencias, Universidad Autónoma de Tamaulipas, México The degradation of soil reduces the capacity of soils to produce food and sustain life. Erosion is one of the main types of soil degradation. Hydric erosion of remontant type can occur in soils located close to the channel of a river through the expansion of a gully that begins as a fluvial incision over the ravine of one side of the river. The incision takes place at the point of greatest flow of runoff from areas adjacent to empty into the river. The depth of the incision causes the growth of the gully by collapse to move their heads back, upstream. The soil loss by remontant erosion on land use in agriculture and livestock was estimated in order to understand the evolution of gullies formed by this type of erosion. Through measurements on satellite images and GPS (Global Positioning System) two gullies, developed on alluvial soils which drain into the river Chihue, were studied. The investigation was conducted during 2003 to 2010 period in the municipality of Jaumave, Tamaulipas, in northeastern Mexico. Soil loss in gullies developed by remontant erosion was large and it was caused by soil collapse and drag of soil on the headers. The estimated loss of soil by remontant erosion was 3500 t in the deeper gully during 2010 and nearly 1200 t per year in the period 2003-2009. New sections of gully of about 20 m length, with more than 3 m deep and up to 13 m wide, were formed each year. This degradation has significantly reduced the productive surface of soil that for many years has been used to the cultivation of maize (Zea mays) and beans (Phaseolus vulgaris) as well as pasture production.

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

    Science.gov (United States)

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

    2016-04-01

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

  16. Macroinvertebrate and diatom metrics as indicators of water-quality conditions in connected depression wetlands in the Mississippi Alluvial Plain

    Science.gov (United States)

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

    2016-01-01

    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.

  17. Distribution and mobility of arsenic in the Río Dulce alluvial aquifers in Santiago del Estero Province, Argentina.

    Science.gov (United States)

    Bhattacharya, Prosun; Claesson, Mattias; Bundschuh, Jochen; Sracek, Ondra; Fagerberg, Jens; Jacks, Gunnar; Martin, Raul A; Storniolo, Angel Del R; Thir, Juan M

    2006-04-01

    Factors controlling arsenic (As) mobilization in the aquifers of the Río Dulce alluvial cone were investigated. Groundwater analyses show severe As contamination (average concentration of 743 mug/L) from geogenic sources, but spatial variability of As concentration is considerable. Sequential leaching of sediment samples from unsaturated zone using de-ionised water, bicarbonate, acetate, and oxalate extracted As to different extents. Sediment oxalate extraction showed that Al and Mn oxide and hydroxides are more abundant than Fe oxides and hydroxides, in spite of similar total Fe, Mn, and Al concentrations in the sediment. Speciation calculations performed for saturated zone samples indicated that Fe and Al oxides and hydroxides are stable in groundwater, suggesting that As adsorption processes may be to some extent controlled by the presence of Fe and Al mineral phases. Principal Component Analysis (PCA) showed that As is related to F, V, Mo, B, Si, most likely due to their common origin in volcanic ash. This suggests the volcanic ash as the probable source of groundwater As. Locally, elevated pH values linked to carbonate dissolution, cation exchange, and dissolution of silicates promote release of adsorbed As. Another factor contributing to the release of As locally may be the input of organic matter from excessive irrigation. The conceptual model of As release includes: i) As influx from dissolution of volcanic glass in volcanic ash, ii) adsorption of As on the surface of Fe and Al mineral phases in relatively low pH zones, and iii) high mobility of As in high pH zones. Future work should be focused on the determination of mineralogical forms of As in volcanic ash and on detailed investigation on factors controlling As mobility. PMID:16055168

  18. Vegetative impacts upon bedload transport capacity and channel stability for differing alluvial planforms in the Yellow River source zone

    Science.gov (United States)

    Li, Zhi Wei; Yu, Guo An; Brierley, Gary; Wang, Zhao Yin

    2016-07-01

    The influence of vegetation upon bedload transport and channel morphodynamics is examined along a channel stability gradient ranging from meandering to anabranching to anabranching-braided to fully braided planform conditions along trunk and tributary reaches of the Upper Yellow River in western China. Although the regional geology and climate are relatively consistent across the study area, there is a distinct gradient in the presence and abundance of riparian vegetation for these reaches atop the Qinghai-Tibet Plateau (elevations in the study area range from 2800 to 3400 m a.s.l.). To date, the influence of vegetative impacts upon channel planform and bedload transport capacity of alluvial reaches of the Upper Yellow River remains unclear because of a lack of hydrological and field data. In this region, the types and pattern of riparian vegetation vary with planform type as follows: trees exert the strongest influence in the anabranching reach, the meandering reach flows through meadow vegetation, the anabranching-braided reach has a grass, herb, and sparse shrub cover, and the braided reach has no riparian vegetation. A non-linear relation between vegetative cover on the valley floor and bedload transport capacity is evident, wherein bedload transport capacity is the highest for the anabranching reach, roughly followed by the anabranching-braided, braided, and meandering reaches. The relationship between the bedload transport capacity of a reach and sediment supply from upstream exerts a significant influence upon channel stability. Bedload transport capacity during the flood season (June-September) in the braided reach is much less than the rate of sediment supply, inducing bed aggradation and dynamic channel adjustments. Rates of channel adjustment are less pronounced for the anabranching-braided and anabranching reaches, while the meandering reach is relatively stable (i.e., this is a passive meandering reach).

  19. Occurrence of volatile organic compounds in shallow alluvial aquifers of a Mediterranean region: Baseline scenario and ecological implications.

    Science.gov (United States)

    Di Lorenzo, T; Borgoni, R; Ambrosini, R; Cifoni, M; Galassi, D M P; Petitta, M

    2015-12-15

    A regional survey of eight volatile organic compounds (VOCs), namely BTEX (benzene, toluene, ethylbenzene and p-xylene) and four chlorinated aliphatic hydrocarbons (CAHs: chloroform, 1,2-dichloroethane, trichloroethene and tetrachloroethene), was carried out at 174 sites, in 17 alluvial aquifers of Abruzzo, a Mediterranean region of southern Italy, from 2004 to 2009. Frequency of detection, concentration range, spatial distribution pattern, and temporal trend of contaminant concentration in each aquifer were analyzed as well as the relationships between VOC concentrations and the total amount of precipitation during the 90days preceding each sampling date. A review of published ecotoxicological data, providing an indication of the biological risk associated with the observed levels of VOC contamination, was presented and discussed. BTEX concentrations were under detection limits in all the investigated aquifers, indicating absence of contamination. In contrast, CAH contamination occurred in 14 out of 17 aquifers. The two most frequently detected compounds were chloroform and tetrachloroethene. No significant temporal trend was observed for chloroform and tetrachloroethene concentrations during the six years of observation, indicating the persistence of stable contaminations, except for some slightly decreasing trends observed in three out of 17 aquifers. In four aquifers chloroform and tetrachloroethene concentrations increased with precipitations in the preceding months. Spatial patterns of contamination differed among aquifers, indicating highly complex contaminant distributions at aquifer scale not related to single-plume geometries. Patterns of contamination by chloroform and tetrachloroethene in the most urbanized aquifers were likely associated with multiple sources of VOCs not clearly detectable at the scale used in this study. In five out of 17 aquifers, chloroform and tetrachloroethene co-occurred at concentrations that are lethal to groundwater

  20. Assessing hyporheic zone dynamics in two alluvial flood plains of the Southern Alps using water temperature and tracers

    Directory of Open Access Journals (Sweden)

    E. Hoehn

    2006-03-01

    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 river Brenno 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 1.9m under the riverbed could be inferred from the time shift of the diurnal temperature signal.

  1. Groundwater Dynamics in Drained Soils of the Biđ-fi eld District

    Directory of Open Access Journals (Sweden)

    Ivan Mustać

    2011-03-01

    Full Text Available The main goal of five-year stationary investigations (2001-2006 was to assess groundwater dynamics in the Biđ-field district, as well as the type of soil moistening of agricultural soils spreading over 5838 ha. Detailed hydropedological investigations were carried out in 2000 and a soil map of the region was produced (scale = 1:10000 using universal kriging. Soil investigations identified six pedosystematic units: alluvial-gley, semigley-pseudogley, eugley hypogley, humogley, eugley amphigley and drained soils. Based on permanent monitoring of piezometer groundwater (piezometer depth up to 4.0 m in the period from 2001 to 2006, the following major soil moistening types and subtypes of the separated soil units were determined: semigley-pseudogely, hypogley, humogley, amphigley and drained. Using the correlation method, more intensive groundwater communication was determined in the studied soil profiles with the River Biđ water (r = 0.65-0.69 than with the River Sava water (r = 0.23-0.69, notably in hypogley soils, which cover 54.3% of the studied area. Analysis of the obtained piezometer water level curves indicated a very strong mutual correlation between the groundwater level dynamics in monitored hydrogeological piezometers of 9 m depth (r = 0.87-0.98, as well as a strong correlation (r = 0.75-0.94 between hydrogeological and hydropedological piezometers of 4 m depth. A particularly strong correlation (r = 0.85-0.94 was recorded between hydrogeological and hydropedological piezometers installed in hypogley soil. These data confirm marked vertical communication of groundwater in the deep aquifer with water of the shallow soil aquifer, indicating that the surface layer of the studied area, mainly made up of silty clay loams to silty clays, is not impervious.

  2. Physical properties of magnesium affected soils in Colombia

    International Nuclear Information System (INIS)

    Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. The Mg+2 accumulation on the exchange complex of soils to a very high saturation levels affect their physical, chemical and biological properties. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley there are about 117,000 hectares affected. There is a lack of information about the soil forming processes, the Mg+2 effects on soils, the type and source of compounds responsible for the magnesium enrichment, their relationship with the landscape and the way this accumulation occurs. To identify and quantify soil Mg+2 enriched areas over 2500 soil profiles from different landscape positions of the Cauca River Valley were studied. The information was processed to generate Mg-saturation maps, to identify the different soil profile types and to estimate the affected area. A topographic sequence from the alluvial inundation plain to the hills was used to explore the presence of diagnostic horizons and to determine the main soil characteristics and genetic, mineralogical or chemical evidences of soil forming processes. Two 180 kilometer transects parallel to the river were used to: a) study the type and source of Mg-compounds responsible for the Mg-enrichment and the way this accumulation occurs. b) the soil hydraulic properties like infiltration, saturated hydraulic conductivity and matrix potential at different depths were also measured. Samples of nine profiles were collected and the porosity and soil volume changes at different water content were examined. The program RETC was used for prediction of the hydraulic properties of non saturated soils. These properties involved the retention curve, the function of hydraulic conductivity and the diffusivity of the water in the soil. By grouping together the soil profiles, five main type of Mg-affected soils were identified as being

  3. Sequestration of Soil Carbon as Secondary Carbonates (Invited)

    Science.gov (United States)

    Lal, R.

    2013-12-01

    , activity and species diversity of soil biota, management of soil fertility and application of Ca-bearing amendments (e.g., lime, single and triple super phosphate, manure), and adoption of conservation-effective measures which trap alluvial and aeolian sediments. Even the low rate of formation of secondary carbonates at 2-5 kg C/ha/yr has implications to aggregation, and microbiological and regolith properties. The isotropic composition of secondary carbonates is a useful tool for reconstructing paleoecological conditions. Researchable priorities include: 1) assessment of the depth distribution of CO2 concentration in soil air and its spatial and temporal variation in relation to tillage systems, crop residue management, fertilizer and manuring, irrigation, cover cropping, agroforestry, etc., 2) understanding the effects of micro and meso-climate (e.g., rainfall, evapotranspiration, air and soil temperatures) on CO2 concentration in soil air, 3) determination of the relation between soil profile characteristics (texture, structure, horizonation, hydrology) and secondary carbonates at present and under paleoecological conditions, 4) establishing the relationship between SOC and SIC pools, 5) determination of the impacts of deforestation, biomass burning, wild fires, drought, inundation, etc., on SIC dynamics, and 6) evaluating the effects of secondary carbonates on soil aggregation and water retention.

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