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Sample records for alluvial saline sodic

  1. 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

  2. Use of saline-sodic water for crop production

    International Nuclear Information System (INIS)

    Waters of different salinity and sodicity levels, both unamended and amended with gypsum and choline chloride, were compared with canal water for their effect on the growth of maize and properties of a garden loam soil. The low salinity water (mixture of tube-well and canal water), when amended by passing through gypsum stone or by addition of choline chloride, gave maize crop yields comparable to those obtained with canal water and had no adverse effect on soil properties. Green matter yield had a negative correlation (r=-0.79**) with soil ESP values

  3. Relationship Between Diurnal Changes of Net Photosynthetic Rate and Influencing Factors in Rice under Saline Sodic Stress

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The net photosynthetic rate of flag leaves and influencing factors under saline sodic soil conditions were investigated at the full heading stage of rice.The net photosynthetic rate of rice leaves showed a double-peak curve in a day in both non-saline sodic and saline sodic soil treatments.The first peak of the net photosynthetic rate appeared at 9:00-10:00 and 9:00 in the saline sodic and non-saline sodic soil treatments,respectively,whereas the second peak both at 14:00.The midday depression of the net photosynthetic rate always appeared regardless of non-saline sodic or saline sodic soil conditions.In addition,the net photosynthetic rate significantly decreased in all day under saline sodic conditions compared with that under non-saline sodic conditions.Some differences were observed in correlation characters between the net photosynthetic rate and all influencing factors during 9:00-13:00.Under non-saline sodic conditions,the diurnal changes of the net photosynthetic rate in a day were mainly caused by stomatal conductance,and the limitation value and the stomatal factors served as determinants;whereas under saline soclic stress,the diurnal changes of the net photosynthetic rate in a day were mainly caused by non stomatal factors including light intensity and air temperature.

  4. Probability mapping of saline and sodic soils in the Harran plain using a non-linear kriging technique

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    Ali Volkan Bilgili

    2013-07-01

    Full Text Available In the Harran Plain, southeastern Turkey, soil salinisation causes land degradation threatening the sustainability of agricultural production. According to a recent survey, approximately 18000 ha area has been affected by soil salinity and sodicity at various levels. Determining the distribution of saline and sodic soils in the study area is the first step for effective management of these soils. Over 200 soil samples have been randomly selected across the plain and analyzed for selected soil salinity and sodicity variables in soil salinity laboratory. Indicator kriging (IK, a non-linear interpolation technique, was used to map the probability levels of occurrence of saline and sodic soils across the plain. The results of IK showed the probability distributions of risky areas under different types of soil salinity classes; nonsaline, saline, salinesodic and sodic.

  5. Effect of Salinity, Sodicity and Soil Texture on Aggregate Stability of Semi-arid Soils

    Science.gov (United States)

    Soil texture, sodicity and salinity or water quality play a significant role in determining soil aggregate stability, hydraulic properties and the response of soil clays to dispersion and swelling. We studied aggregate stability from 60 samples of Israeli top soils, widely varying in clay content an...

  6. Morphological and structural plasticity of grassland species in response to a gradient in saline-sodic soils.

    Science.gov (United States)

    Huang, Y; Song, Y; Li, G; Drake, P L; Zheng, W; Li, Z; Zhou, D

    2015-11-01

    The abundance and distribution of species can be ascribed to both environmental heterogeneity and stress tolerance, with the latter measure sometimes associated with phenotypic plasticity. Although phenotypic plasticity varies predictably in response to common forms of stress, we lack a mechanistic understanding of the response of species to high saline-sodic soils. We compared the phenotypic plasticity of three pairs of high and low saline-sodic tolerant congeners from the families Poaceae (Leymus chinensis versus L. secalinus), Fabaceae (Lespedeza davurica versus L. bicolor) and Asteraceae (Artemisia mongolica versus A. sieversiana) in a controlled pot experiment in the Songnen grassland, China. The low tolerant species, L. secalinus and A. sieversiana exhibited higher plasticity in response to soil salinity and sodicity than their paired congeners. Highly tolerant species, L. chinensis and A. mongolica, had higher values for several important morphological traits, such as shoot length and total biomass under the high saline-sodic soil treatment than their paired congeners. In contrast, congeners from the family Fabaceae, L. davurica and L. bicolor, did not exhibit significantly different plasticity in response to soil salinity and sodicity. All species held a constant reproductive effort in response to saline-sodic soil stress. The different responses between low and high tolerant species offer an explanation for the distribution patterns of these species in the Songnen grassland. Highly tolerant species showed less morphological plasticity over a range of saline-sodic conditions than their paired congeners, which may manifest as an inability to compete with co-occurring species in locations where saline-sodic soils are absent. PMID:26177120

  7. Comparison of gypsum and potassium silicate for reclamation of saline sodic soil

    International Nuclear Information System (INIS)

    Relative efficiency of gypsum, potassium silicate and their combinations at different levels for reclamation of saline sodic soil was tested. Treatments were replicated thrice. All pots were arranged according to completely randomized design and treatments were applied to the soil according to treatment plan. Appropriate time was given to achieve the reclamation of saline sodic soil and relative efficiency was assessed through laboratory analysis. After this, rice seedling (Shaheen Basmati) was transplanted in all the pots i.e., 3 plants per pot. Necessary N, P and K fertilizers were applied at the recommended rate. After crop harvest, soil samples were taken for analysis of pH, electrical conductivity (EC), sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) of soil. All the amendments when used alone or in combination with each other improved the chemical parameters of soil. All levels of gypsum (100%, 75% and 50% G.R) proved effective in lowering pH, EC, SAR and ESP of saline sodic soil. Similar trend was observed with the use of all levels of potassium -1 silicate (225, 150 and 75mg per kg soil) of soil. Combinations of gypsum and potassium silicate also remained better in this regard. The most effective treatment was application of the full required rate of gypsum. (author)

  8. Salinity and sodicity of weathered minesoils in Northwestern New Mexico and Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Musslewhite, B.D.; Vinson, J.R.; Johnston, C.R.; Brown, T.H.; Wendt, G.W.; Vance, G.F. [BHP Billiton, Farmington, NM (United States). New Mexico Coal

    2009-05-15

    Evolving relationships between electrical conductivity (EC) and sodium adsorption ratio (SAR) in reconstructed soils at surface mines have been insufficiently documented in the literature. Some minesoils (i.e., rootzone material) are classified as saline, sodic, or saline-sodic and are considered unsuitable for revegetation. Weatherable minerals such as calcite and gypsum are common in alkaline minesoils and on dissolution tend to mitigate elevated SAR levels by maintaining or increasing electrolytes in the soil and providing sources of exchangeable calcium and magnesium. Topsoils (i.e., coversoils) contribute to mitigation of sodic conditions when soluble cations are translocated from coversoils into the underlying minesoils. This study evaluated the weathering characteristics of minesoils sites from three surface coal mines in northwestern New Mexico and northeastern Arizona. Minesoils were grouped into 11 classes based on EC and SAR. After 6 to 14 yr, differences between upper and lower halves of the coversoils suggest general increases occurred with EC, SAR, chloride (Cl{sup -}), and sulfate (SO{sub 4}{sup 2-}) with depth. Within the reclaimed minesoils, there were several significant (P < 0.05 or < 0.10) relationships among EC and SAR that related to Minesoil Class. Lower SAR levels with corresponding increases in EC compared to baseline minesoils were more apparent in upper minesoil depths (0-5 and 5-15 cm). Minesoil anion concentrations suggested coversoil leachates and gypsum dissolution influenced EC and SAR chemistry. Over time, chemical changes have increased the apparent stability of the saline and sodic reclaimed minesoils studied thereby reducing risks associated with potential aggregate slaking and clay particle dispersion.

  9. Irrigation with saline-sodic water: effects on two clay soils

    OpenAIRE

    Giovanna Cucci; Giovanni Lacolla

    2013-01-01

    The results of a 4-year experiment aimed at evaluating the effect of irrigation with saline-sodic water on the soil are reported. The research was carried out at the Campus of the Agricultural Faculty of Bari University (Italy) on 2 clay soils (Bologna – T1 and Locorotondo – T2). The soils were cropped to borlotto bean (Phaseolus vulgaris L.), capsicum (Capsicum annuum L.), sunflower (Helianthus annuus L.), wheat (Triticum durum Desf) grown in succession; the crops were irrigated with 9 salin...

  10. Soil Salinity Changes Under Cropping with L ycium barbarum L.and Irrigation with Saline-Sodic Water

    Institute of Scientific and Technical Information of China (English)

    DOU Chao-Yin; KANG Yao-Hu; WAN Shu-Qin; HU Wei

    2011-01-01

    In order to utilize the wasted saline-sodic soils under shallow groundwater condition,a 3-year field study was carried in a field cropped with Lycium barbarum L.and irrigated by drip irrigation with saline groundwater under the water table depth of 30-40 cm in the northern Yinchuan Plain,China.Effects of cropping duration (one,two,and three years) on soil salinity,soil solution composition,and pH in three adjacent plots were investigated in 2008.Results showed that a high irrigation frequency maintained high soil water potential and subsequently facilitated infiltration and downward movement of water and salt in the crop root zone.Salt accumulated on the edges of the ridges,and soil saturated-paste electrical conductivity (ECe) was higher in the edge.Concentrations of Na+,Ca2+,Mg2+,Cl-,and SO42- in the soil increased with the soil depth as did the ECe,while HCO3- and pH had a relative uniform distribution in soil profile.As planting year increased,the ECe and soil salts in the field had a decreasing tendency,while in the root zone they decreased immediately after irrigation and then remained relatively stable in the following growing seasons.HCO3- and pH had little change with the planting year.Results suggested that the application of drip irrigation with saline water could ameliorate saline-sodic soil and provide a relatively feasible soil environment for the growth of salt-tolerant plant Lycium barbarum L.under the saline-sodic soils with shallow groundwater.

  11. Saline-sodic soils and their management in Pakistan

    International Nuclear Information System (INIS)

    This paper gives a short review of the soil salinity problem in Pakistan and discusses briefly the measures that have been taken to tackle it. It describes a biological approach of the economic utilization of salt-affected lands by plant succession through initial colonization with salt-tolerant plant species, and describes results of the practical application of this approach and the role of nuclear techniques in these studies. (author)

  12. Irrigation with saline-sodic water: effects on two clay soils

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    Giovanna Cucci

    2013-05-01

    Full Text Available The results of a 4-year experiment aimed at evaluating the effect of irrigation with saline-sodic water on the soil are reported. The research was carried out at the Campus of the Agricultural Faculty of Bari University (Italy on 2 clay soils (Bologna – T1 and Locorotondo – T2. The soils were cropped to borlotto bean (Phaseolus vulgaris L., capsicum (Capsicum annuum L., sunflower (Helianthus annuus L., wheat (Triticum durum Desf grown in succession; the crops were irrigated with 9 saline-sodic types of water and subjected to two different leaching fractions (10% and 20% of the watering volume. The 9 solutions were obtained dissolving in de-ionised water weighted amounts of sodium chloride (NaCl and calcium chloride (CaCl2, deriving from the combination of 3 saline concentrations and 3 sodicity levels. The crops were irrigated whenever the water lost by evapotranspiration from the soil contained in the pots was equal to 30% of the soil maximum available water. The results showed that, though the soils were leached during the watering period, they showed a high salt accumulation. Consequently, the saturated soil extract electrical conductivity increased from initial values of 0.65 and 0.68 dS m-1 to 11.24 and 13.61 dS m-1 at the end of the experiment, for the soils T1 and T2, respectively. The saline concentration increase in irrigation water caused in both soils a progressive increase in exchangeable sodium, and a decrease in exchangeable calcium and non-significant variations in exchangeable potassium (K and magnesium (Mg.

  13. Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

    OpenAIRE

    Dongdong Liu; Dongli She; Shuang’en Yu; Guangcheng Shao; Dan Chen

    2014-01-01

    This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related ...

  14. Absorption of applied zinc(Zn65) as affected by nitrogen and amendments in normal and saline-sodic zinc

    International Nuclear Information System (INIS)

    The absorption of applied zinc (Zn65) by corn plants in saline sodic-soils of different pHs was studied. The effect of NH4NO3 and gypsum in this respect was also investigated. Nitrogen application with Zn increased the concentration of Zn in the plants irrespective of the soil character. In saline-sodic soils, the application of gypsum was more effective than nitrogen. Gypsum application followed by leaching with water increased the concentration of Zn as compared to gypsum application without leaching, indicating that the presence of sodium in exchangeable or soluble forms decreases the absorption of Zn by plants. (author)

  15. Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture.

    Science.gov (United States)

    Qadir, M; Oster, J D

    2004-05-01

    Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future

  16. Sulphur supply enhances wheat growth and yield on saline-sodic soil

    International Nuclear Information System (INIS)

    The effect of different S levels (0, 25, 50 and 75 kg S/ha) on growth and ionic concentration of wheat variety Inqlab-91 directly sown on saline-sodic soil (ECe=5.65 dS/m, pH=8.57 and SAR=17.38) was evaluated in a field experiment. Treatments were arranged using randomized complete block design (RCBD) with three replications. The crop was harvested at maturity, data on tillering, plant height, spike length, number of grains/spike, 1000- grain weight and yields (grain and straw) were recorded. Na, K, Ca and S concentrations in grain and straw were estimated using atomic absorption spectroscopy. Tillering, number of grains/spike, 1000- grain weight and grain yield significantly (p<0.05) increased by enhancing the S application. Maximum wheat yield (4.66 t/ha) was recorded when S was applied at 75 kg/ha, which was 43% more than the control treatment. Maximum number of tillers/plant (161) and number of grains/spike (56) were recorded with sulphur applied at 75 kgiha. Positive correlation (r = 0.85), (r = 0.88) between calcium, potassium and negative correlation (r = -0.84) between grain sodium content and wheat grain yield was recorded. It indicates that presence of significantly higher Ca and K contents of grain receiving S application might possibly help plants to attain more Ca and K and avoided sodium uptake to alleviate salinity/sodicity stress. Economical analysis showed that maximum value cost ratio (5.5: I) was achieved with the application of 25 kg S/ha. (author)

  17. Effect of salinity and sodicity stresses on physiological response and productivity in Helianthus annuus.

    Science.gov (United States)

    Farghaly, Fatma Aly; Radi, Abeer Ahmed; Abdel-Wahab, Dalia Ahmed; Hamada, Afaf Mohamed

    2016-06-01

    Soil salinity and sodicity (alkalinity) are serious land degradation issues worldwide that are predicted to increase in the future. The objective of the present study is to distinguish the effects of NaCl and Na(2)CO(3) salinity in two concentrations on the growth, lipoxygenase (LOX) activity, membrane integrity, total lipids, yield parameters and fatty acids (FAs) composition of seeds of sunflower cultivar Sakha 53. Plant growth, LOX activity and malondialdehyde (MDA) content were reduced by salts stresses. On the contrary, salinity and alkalinity stress induced stimulatory effects on membrane permeability, leakage of UV-metabolites from leaves and total lipids of sunflower shoots and roots. Crop yield (plant height, head diameter, seed index and number of seeds for each head) that is known as a hallmark of plant stress was decreased by increasing concentrations of NaCl and Na(2)CO(3) in the growth media. Fatty acid methyl esters (FAME) composition of salt-stressed sunflower seeds varied with different levels of NaCl and Na(2)CO(3). PMID:27165529

  18. Reclaiming Saline-Sodic Soils Using Electrochemical Processes: A Case Study From Sahl El-Tina Plain, Egypt

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    Abdel-Fattah Mohamed K.

    2014-10-01

    Full Text Available A leaching experiment was conducted using column techniques assessing efficiency of electrochemical process to reclaim saline-sodic soils. Soil material was collected from Sahl El-Tina plain, which located in North West coast of Sinai, Egypt. The experiment was designed as factorial randomized complete block and all treatments were replicated three times. Two 2.5 cm diameterx30 cm height mild stainless steel tubes were inserted into the soil matrix to serve as electrodes (i.e. cathode and anode. Distance between cathode and anode was 10 cm. Electrodes were supplied by a direct current (DC power supply; Volt ages of 0.3 or 9 Volt. Leaching was done using the intermittent method so as to add portions to the already saturated soil columns, and obtain leachates equal to the added portions. Pore volume 0.1 PV was used in the leaching processes which are equal 498.4 cm3, i.e. PV being volume of pores per column, thus 1 PV equals volume of pores (cm3 expressed as water quantity. Electric remediation increased ionic mobility and separated salts from soil. All treatments decreased soil EC and soil sodicity expressed as SAR and ESP. Results showed that 9 Volt treatment was more effective in decreasing the soil EC and soil sodicity than the other treatments. Efficiency of treatments were 9-Volt > 3-Volt > leaching alone (non-DC treatment. This study suggests that leaching using direct current (DC led to improvement of the chemical properties of saline sodic soils and required a short time to reclaim saline-sodic soils compared with leaching alone.

  19. IMPACT OF SALINITY AND SODICITY ON BIOMASS, TOTAL NITROGEN, NITRATE REDUCTASE ACTIVITY, LEAF AREA, AND CHLOROPHYLL CONTENTS IN MAIZE (ZEA MAYS L.

    Directory of Open Access Journals (Sweden)

    M. GUFRAN KHAN*, SHIMELIS*, G., ALEMU, H.* AND KEBENU, F**

    2014-11-01

    Full Text Available ABSTRACT: Salinity and sodicity are major constraint in increasing crop production at global level. Millions of the hectares of the land are too saline to produce economic yield.  In Ethiopia, 11 million ha of land is salt affected, about half of these soils are saline and remaining half are saline - sodic and sodic soil. As most of the arable land and quality water resources have already been exploited, the use of saline or urban/industrial waste water may be a viable alternative for further agro production. In view of such perspectives, an investigation was conducted to examine the effect of salinity (NaCl and sodicity (Na2CO3 on  biomass, total nitrogen, nitrate reductase activity, leaf area, and chlorophyll contents in Maize (Zea mays L. plants. The appropriate amount of NaCl and Na2CO3  was  dissolved in distilled water for appraisal of artificial  salinity and sodicity levels ( 0 , 4, 8,  and 12  and  mScm-1 in soil medium. Plants were also supplied with potassium (0 and 5mM KNO3 as remedial treatment. Maize plants were analyzed for germination, early growth, biomass, total nitrogen, Nitrate reductase activity, Leaf area, and chlorophyll contents as grown under different ECe levels of salinity and sodicity. The extent of salinity and sodicity effects was compared on the basis of different parameters. It was observed that plants showed substantial reduction in all parameters due to imposition of salinity and sodicity in root medium and it was more so due to sodicity. However, the use of additional potassium brought about an enhancement in these parameters.  It is suggested that plants may be raised in saline soil and saline water however; the extent of success depends upon salinity and sodicity levels, remedial treatments and plant species. The outcome of the present work may contribute towards viable utilization of saline soil and water for enhancing agro production of suitable crops, a desired goal to achieve food security.

  20. Geochemical Modeling of Trivalent Chromium Migration in Saline-Sodic Soil during Lasagna Process: Impact on Soil Physicochemical Properties

    OpenAIRE

    Salihu Lukman; Alaadin Bukhari; Al-Malack, Muhammad H.; Mu’azu, Nuhu D.; Essa, Mohammed H.

    2014-01-01

    Trivalent Cr is one of the heavy metals that are difficult to be removed from soil using electrokinetic study because of its geochemical properties. High buffering capacity soil is expected to reduce the mobility of the trivalent Cr and subsequently reduce the remedial efficiency thereby complicating the remediation process. In this study, geochemical modeling and migration of trivalent Cr in saline-sodic soil (high buffering capacity and alkaline) during integrated electrokinetics-adsorption...

  1. Growth and yield of different brassica genotypes under saline sodic conditions

    International Nuclear Information System (INIS)

    A field study was conducted at farmer's salt-affected field (ECe=12.3 dS m/sup -1/; pH=9.7; SAR=46.2) in Hafizabad to test growth and yield response of six Brassica cultivars (BARD-I, Dunkled, Rainbow, BRS-II, Sultan Raya and cv. 95102-5) under saline sodic conditions. Data on growth and yield parameters were collected randomly (average of five plants per replication) at the time of crop maturity. Ionic concentration in plant tissues and oil content in seeds were also determined. Comparatively more number of branches and pods per plant were produced by cultivar Dunkled closely followed by BARD-I while maximum seed yield (241.7 and 235.1 kg ha ) was obtained from Dunkled and Sultan Raya, respectively which was statistically at par. However, BRS-II and Rainbow showed significantly more percent oil contents in their seeds but genotype Dunkled showed minimum Na+ and K+ concentration in their tissues. (author)

  2. Effect of soil to water ratios on chemical properties of saline-sodic and normal soil

    International Nuclear Information System (INIS)

    In a laboratory study, effect of soil to water ratios on pH, soluble salts and exchangeable cations status of saline-sodic normal soil series was studied. The soil to water ratios tested against saturated paste method were 1:1, 1:2, 1:5 and 1:10. Soluble ions (Na, Ca+Mg, CO/sub 3/+HCO/sub 3/ and SO/sub 4/ except Cl) increased in all soils with increasing moisture contents. The pH of soil increased at all soil to water ratios except soil No. 3 and 4 where it decreased at 1:5 and 1:10 ratio. The exchangeable Na and K decreased while exchangeable Ca+Mg increased with increasing moisture contents. The exchangeable sodium percentage (ESP) calculated at various soil to water ratios decreased as compared to that at saturated percentage. Since the saturation percentage was directly related to field conditions. The saturated paste method is the best for accurate determination of pH, soluble salts and exchangeable cations and thus for classification and reclamation of salt-affected soils.(author)

  3. Bacteria in combination with fertilizers promote root and shoot growth of maize in saline-sodic soil

    Directory of Open Access Journals (Sweden)

    Muhammad Zafar-ul-Hye

    2015-03-01

    Full Text Available Salinity is the leading abiotic stress hampering maize (Zea maysL. growth throughout the world, especially in Pakistan. During salinity stress, the endogenous ethylene level in plants increases, which retards proper root growth and consequent shoot growth of the plants. However, certain bacteria contain the enzyme 1-aminocyclopropane-1-carboxylate (ACC deaminase, which converts 1-aminocyclopropane-1-carboxylic acid (an immediate precursor of ethylene biosynthesis in higher plants into ammonia and α-ketobutyrate instead of ethylene. In the present study, two Pseudomonas bacterial strains containing ACC-deaminase were tested separately and in combinations with mineral fertilizers to determine their potential to minimize/undo the effects of salinity on maize plants grown under saline-sodic field conditions. The data recorded at 30, 50 and 70 days after sowing revealed that both the Pseudomonas bacterial strains improved root and shoot length, root and shoot fresh weight, and root and shoot dry weight up to 34, 43, 35, 71, 55 and 68%, respectively, when applied without chemical fertilizers: these parameter were enhanced up to 108, 95, 100, 131, 100 and 198%, respectively, when the strains were applied along with chemical fertilizers. It can be concluded that ACC-deaminase Pseudomonas bacterial strains applied alone and in conjunction with mineral fertilizers improved the root and shoot growth of maize seedlings grown in saline-sodic soil.

  4. Bacteria in combination with fertilizers promote root and shoot growth of maize in saline-sodic soil.

    Science.gov (United States)

    Zafar-Ul-Hye, Muhammad; Farooq, Hafiz Muhammad; Hussain, Mubshar

    2015-03-01

    Salinity is the leading abiotic stress hampering maize ( Zea mays L.) growth throughout the world, especially in Pakistan. During salinity stress, the endogenous ethylene level in plants increases, which retards proper root growth and consequent shoot growth of the plants. However, certain bacteria contain the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which converts 1-aminocyclopropane-1-carboxylic acid (an immediate precursor of ethylene biosynthesis in higher plants) into ammonia and α-ketobutyrate instead of ethylene. In the present study, two Pseudomonas bacterial strains containing ACC-deaminase were tested separately and in combinations with mineral fertilizers to determine their potential to minimize/undo the effects of salinity on maize plants grown under saline-sodic field conditions. The data recorded at 30, 50 and 70 days after sowing revealed that both the Pseudomonas bacterial strains improved root and shoot length, root and shoot fresh weight, and root and shoot dry weight up to 34, 43, 35, 71, 55 and 68%, respectively, when applied without chemical fertilizers: these parameter were enhanced up to 108, 95, 100, 131, 100 and 198%, respectively, when the strains were applied along with chemical fertilizers. It can be concluded that ACC-deaminase Pseudomonas bacterial strains applied alone and in conjunction with mineral fertilizers improved the root and shoot growth of maize seedlings grown in saline-sodic soil. PMID:26221093

  5. Effect of age of seedlings of new rice lines/varieties on paddy yield in saline/sodic soil

    International Nuclear Information System (INIS)

    To study the effect of age of seedlings on paddy yield, a trial was conducted by using fine rice lines/varieties under saline sodic soil heaving pH 8.6-8.9, ECe 4.2-4.9 (dSm/sup -1/) and SAR 35.0-42.2 (mmol L-1) /sup 0.5/. Seedlings of five advance lines/varieties (SRI-8, SRI-13, PB-95, Shaheen Basmati and Super Basmati) of 21, 28, 35, 42 and 49 days age were transplanted in saline sodic soil. The results revealed that maximum paddy yield (3.74 and 3.72 t.ha/sup -1/) was obtained from 35 and 42 days old rice seedlings respectively which was followed by 28 days old seedlings (3.31 t.ha/sup -1/). The interaction between rice advance lines/varieties and age of rice seedlings was also significant. The new advance line, PB-95 of 35 days old seedlings produced the highest paddy yield of 4.19 t.ha/sup -1/. (author)

  6. Geochemical modeling of trivalent chromium migration in saline-sodic soil during Lasagna process: impact on soil physicochemical properties.

    Science.gov (United States)

    Lukman, Salihu; Bukhari, Alaadin; Al-Malack, Muhammad H; Mu'azu, Nuhu D; Essa, Mohammed H

    2014-01-01

    Trivalent Cr is one of the heavy metals that are difficult to be removed from soil using electrokinetic study because of its geochemical properties. High buffering capacity soil is expected to reduce the mobility of the trivalent Cr and subsequently reduce the remedial efficiency thereby complicating the remediation process. In this study, geochemical modeling and migration of trivalent Cr in saline-sodic soil (high buffering capacity and alkaline) during integrated electrokinetics-adsorption remediation, called the Lasagna process, were investigated. The remedial efficiency of trivalent Cr in addition to the impacts of the Lasagna process on the physicochemical properties of the soil was studied. Box-Behnken design was used to study the interaction effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil pH, electroosmotic volume, soil electrical conductivity, current, and remedial efficiency of trivalent Cr in saline-sodic soil that was artificially spiked with Cr, Cu, Cd, Pb, Hg, phenol, and kerosene. Overall desirability of 0.715 was attained at the following optimal conditions: voltage gradient 0.36 V/cm; polarity reversal rate 17.63 hr; soil pH 10.0. Under these conditions, the expected trivalent Cr remedial efficiency is 64.75%. PMID:25152905

  7. Coupled electrokinetics-adsorption technique for simultaneous removal of heavy metals and organics from saline-sodic soil.

    Science.gov (United States)

    Lukman, Salihu; Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Bukhari, Alaadin

    2013-01-01

    In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils. PMID:24235885

  8. Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

    Directory of Open Access Journals (Sweden)

    Salihu Lukman

    2013-01-01

    Full Text Available In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils.

  9. Geochemical Modeling of Trivalent Chromium Migration in Saline-Sodic Soil during Lasagna Process: Impact on Soil Physicochemical Properties

    Directory of Open Access Journals (Sweden)

    Salihu Lukman

    2014-01-01

    Full Text Available Trivalent Cr is one of the heavy metals that are difficult to be removed from soil using electrokinetic study because of its geochemical properties. High buffering capacity soil is expected to reduce the mobility of the trivalent Cr and subsequently reduce the remedial efficiency thereby complicating the remediation process. In this study, geochemical modeling and migration of trivalent Cr in saline-sodic soil (high buffering capacity and alkaline during integrated electrokinetics-adsorption remediation, called the Lasagna process, were investigated. The remedial efficiency of trivalent Cr in addition to the impacts of the Lasagna process on the physicochemical properties of the soil was studied. Box-Behnken design was used to study the interaction effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil pH, electroosmotic volume, soil electrical conductivity, current, and remedial efficiency of trivalent Cr in saline-sodic soil that was artificially spiked with Cr, Cu, Cd, Pb, Hg, phenol, and kerosene. Overall desirability of 0.715 was attained at the following optimal conditions: voltage gradient 0.36 V/cm; polarity reversal rate 17.63 hr; soil pH 10.0. Under these conditions, the expected trivalent Cr remedial efficiency is 64.75 %.

  10. Use of textile waste water along with liquid NPK fertilizer for production of wheat on saline sodic soils.

    Science.gov (United States)

    Yaseen, Muhammad; Aziz, Muhammad Zahir; Jafar, Abdul Aleem; Naveed, Muhammad; Saleem, Muhammad

    2016-05-01

    A field experiment in collaboration with a private textile industry (Noor Fatima Fabrics Private (Ltd.), Faisalabad) was conducted to evaluate the effect of disposed water from bleaching unit, printing unit and end drain for improving growth and yield of wheat under saline sodic soil. Textile waste water along with canal water (control) was applied with and without liquid NPK fertilizer. The application of liquid NPK fertilizer with end drain waste water increased plant height, spike length, flag leaf length, root length, number of tillers (m(-2)), number of fertile tillers (m(-2)), 1000 grain weight, grain yield, straw yield and biological yield up to 21, 20, 20, 44, 17, 20, 14, 44, 40 and 41%, respectively compared to canal water (control). Similarly, the NPK uptake in grain was increased up to 15, 30 and 28%, respectively by liquid fertilizer treated end drain water as compare to canal water with liquid fertilizer. Moreover, concentration of different heavy metals particularly Cu, Cr, Pb and Cd was decreased in grains by application of waste water along with liquid NPK. The result may imply that waste water application along with liquid-NPK could be a novel approach for improving growth and yield of wheat in saline sodic soils. PMID:26515426

  11. Artificial Neural Networks to predict decreasing saturated hydraulic conductivity in soils irrigated with saline-sodic water.

    Directory of Open Access Journals (Sweden)

    Younes Daw Ezlit

    2014-05-01

    Full Text Available Multilayer Artificial Neural Networks (ANNs with the backpropagation algorithm were used to estimate the decrease in relative saturated conductivity due to an increase in sodicity and salinity. Data from the literature on the relative saturated hydraulic conductivity measured using water having levels of sodicity and salinity in different types of semiarid soils were used. The clay content of these soils is predominantly montmorillonite. The input data consisted of clay percentage, cation exchange capacity, electrolyte concentration, and estimated soil exchangeable sodium percentage at equilibrium stage with the solution applied. The data was divided into three groups randomly to meet the three phases required for developing the ANNs model (i. e. training, evaluation, and testing.The activation function selected was the TANSIG layer in the middle, while the exit function was the PURELIN layer. The comparisons between the experimental and predicted data on relative saturated hydraulic conductivity during training and testing phases showed good agreement. This was evident from the statistical indicators used for the evaluation process. For the training phase, the values of mean absolute error (MAE, root mean square error (RMSE, the correlation coefficient (r and the determination coefficient (R2 were 0.08, 0.13, 0.91, and 0.83, respectively. The performance of the ANNs model was evaluated against a part of the data selected randomly form the whole set of data collected (i. e. data not used during the model testing phase. The resultant values for MAE and RMSE, r and R2 were 0.12, 0.16, 0.82 and 0.68, respectively. It should be noted that many factors were not considered, such as soil pH, type of clay, and organic matter, due to the limitations of the data available. Using these factors as input in ANNs might improve model predictions. However, the results suggested that the ANNs model performs well in soils with very low levels of organic matter.

  12. Incorporação de gesso para correção da salinidade e sodicidade de solos salino-sódicos Incorporation of gypsum to correct the salinity and sodicity of saline-sodic soils

    Directory of Open Access Journals (Sweden)

    Antonio N. Tavares Filho

    2012-01-01

    Full Text Available Com o objetivo de avaliar o efeito da aplicação do gesso nas características químicas de solos salino-sódicos coletados no Perímetro Irrigado do Moxotó, localizado no município de Ibimirim, PE, um experimento foi realizado em colunas de solo instaladas no Laboratório de Mecânica do Solo e Aproveitamento de Resíduo da Universidade Federal Rural de Pernambuco. Os tratamentos foram dispostos em um delineamento inteiramente casualizado com esquema fatorial de dois solos (S1 e S2 e sete níveis da necessidade de gesso (50, 75, 100, 125, 150, 175 e 200% determinado pelo Método de Laboratório Schoonover-M1. O gesso foi incorporado aos solos, em três repetições, totalizando 42 unidades experimentais. As variáveis avaliadas foram: i condutividade elétrica (CE, ii cátions solúveis e iii relação de adsorção de sódio (RAS no extrato de saturação do solo. O nível de 100% da necessidade de gesso causou diminuição da sodicidade para valores de RAS Aiming to evaluate the effect of gypsum on the modification of chemical properties of saline-sodic soils collected in the Irrigated Perimeter of Ibimirim-PE, an experiment was carried out in soil columns installed at the Soil Mechanics and Residue Recovery Laboratoy at the Universidade Federal Rural de Pernambuco. The treatments were arranged in a completely randomized design with factorial arrangement of two soils (S1 and S2 and seven levels of gypsum requirement (50, 75, 100, 125, 150, 175 and 200% determined by the Laboratory Method Schoonover-M1. The gypsum was incorporated in to the soils, in three replications, totaling 42 experimental units. The parameters evaluated were: electrical conductivity (EC, soluble cations and sodium adsorption ratio (SAR in the saturation extract of soil. The level of the 100% of gypsum requirement caused decreased in sodicity values of SAR under 13 (mmol L-1½, presenting itself as an effective method in reducing the levels of sodium in areas affected

  13. Evaluating the Potential of Biochars and Composts as Organic Amendments to Remediate a Saline-Sodic Soil Leached with Reclaimed Water

    OpenAIRE

    Chaganti, Vijayasatya Nagendra

    2014-01-01

    Use of organic amendments in lieu of more expensive inorganic amendments is increasingly seen as a sustainable alternative for reclaiming salt-affected soils. Moreover, due to the scarcity of fresh waters for agricultural irrigation, alternatives such as use of low quality reclaimed waters and drainage waters are encouraged. The main objectives of this dissertation were (1) to evaluate whether composts and/or biochars can be used to reclaim a saline sodic soil in conjunction with reclaimed wa...

  14. Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

    OpenAIRE

    Mohammed Hussain Essa; Nuhu Dalhat Mu’azu; Salihu Lukman; Alaadin Bukhari

    2013-01-01

    In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the effects of voltage gradient, initial contaminant c...

  15. Energy and water exchange from a saline-sodic overburden restoration cover, Fort McMurray, Alberta

    International Nuclear Information System (INIS)

    The Canadian oil sand mining industry takes responsibility for restoring mining areas to an equivalent level that existed before mining occurred. During this process, the surface-vegetation-atmosphere continuum is dramatically altered, creating few similarities to the boreal forest that existed prior to mining. Using the eddy covariance method, a study of the integrated salt and water balance of a saline-sodic overburden pile at Syncrude Canada Ltd.'s Mildred Lake mine north of Fort McMurray, Alberta was undertaken in order to measure the surface energy balance for three summers (2003 - 2005) with different climatic and phenological conditions. The objective of this study was to document how evapotranspiration and energy partitioning varied inter-annually during the growing season atop the restoration cover and to relate the portioning of energy at the surface to environmental and physiological variables. The paper described the site and measurement specifics and also presented the results and discussion. Results were organized under the following topics: climate; soil moisture and suction; leaf area index and vegetation; surface energy balance; evapotranspiration; and controls on evapotranspiration. It was concluded that results from this study have important implications for recovery strategies, as the availability water for plant growth, the movement and migration of salts and percolating water for deep drainage all depend on accurate quantification of evapotranspiration. 9 refs., 1 tab

  16. Influence of Irrigation Water Discharge Frequency on Soil Salt Removal and Rice Yield in a Semi-Arid and Saline-Sodic Area

    OpenAIRE

    Zhigang Huang; Yueqing Chen; Guangxin Zhang; Y. Jun Xu

    2013-01-01

    Irrigation practice for rice culture can be especially challenging in areas with limited water supply and soil salinization. In this study, we carried out a field experiment to assess the effects of different water discharge frequencies on soil salt content, rice yield and water use efficiency on a saline-sodic soil in a semi-arid region of Northeast China. The experiment comprised of three frequency levels of discharge [9-time (I-9-30), 6-time (I-6-30) and 3-time (I-3-30) discharge, all foll...

  17. Effects of Saline and Sodic Stress on Yield and Fatty Acid Profile in Sunflower Seeds

    Directory of Open Access Journals (Sweden)

    Emanuele Tarantino

    2011-02-01

    Full Text Available Among the objectives concerned in this research, much importance has been attached to the assessment of the influence of soil type, irrigation water quality and leaching requirement on the production and composition in fatty acids of sunflower oil. The trial was run in 2001 on a sunflower crop (cv. HS 90 grown in cylindrical pots at the Campus of Bari University (Italy. 36 treatments obtained from the factorial combination of two clay soils with nine types of brackish water and two leaching fractions (10 and 20% were compared. The nine types of irrigation water were obtained by dissolving the proper amounts of NaCl and CaCl2 in de-ionized water, according to the factorial combination of three salt concentration levels (0.01, 0.032 and 0.064 M with three sodium levels (SAR = 5, 15 and 45. At ripening the main yield traits, oil yield and acid composition of seeds were analysed. At the highest salinity level about 70% yield reduction, in terms of seeds per plant was observed. The oil yield and the final acid composition of seeds were significantly affected by soil type, leaching requirement, salinity and the SAR levels of irrigation water. A progressive decline in oil yield was recorded as the salt concentration and sodium level of irrigation solutions increased. As to the fatty acid composition, a gradual increase in oleic and linolenic acid content and a corresponding decrease in the other fatty acids were found as the salinity and sodium levels of irrigation water increased. The oleic/linoleic acid ratio too increased as the salinity increased. The salt and sodium-induced stresses of irrigation water reduced the seed and oil yields while still favouring a progressive increase in the oleic acid content and a slight decrease of linoleic, palmitic and stearic acids, thus improving oil quality. The results point out both the influence of the soil and the positive effect of sodium and salt stress and of the leaching fraction on the food quality of

  18. Sources of elevated salinity in the Mississippi River Alluvial Aquifer, south-central Louisiana, USA

    International Nuclear Information System (INIS)

    Highlights: → Salinization is impacting groundwater quality in southern Louisiana, USA. → This includes the Mississippi River Alluvial Aquifer. → Geochemical evidence indicates salt dome dissolution is responsible. → Thus, salinization here is a natural, on-going process. → The potential for remediation is slight, if not non-existent. - Abstract: Salinization is a process impacting groundwater quality and availability across much of southern Louisiana, USA. However, a broad divergence of opinion exists regarding the causes of this elevated salinity: updip-migrating marine waters from the Gulf of Mexico, saline fluids migrating up fault planes, movement of water from salt domes, and/or remnant seawater from the last major marine transgression. The Mississippi River Alluvial Aquifer (MRAA) in south-central Louisiana is recharged by the Mississippi River, and there are discharge zones to the west and east. Recharge waters from the Mississippi River are fresh, but Cl- levels in the western portions of the aquifer are as high as 1000 mg/L. The aquifer is an important source of water for several municipalities and industries, but prior to this study the source(s) of the elevated salinity or whether the salinization can be remediated had not been determined. The low Br/Cl ratios in the groundwaters are consistent with a saline endmember produced by subsurface dissolution of salt domes, not a marine source. The H and O isotopic systematics of the aquifer waters indicate meteoric sources for the H2O, not marine waters or diagenetically-altered deep brines. The westward salinization of aquifer water represents a broad regional process, instead of contamination by point sources. Mapping of spatial variations in salinity has permitted the identification of specific salt domes whose subsurface dissolution is producing waters of elevated salinity in the aquifer. These include the Bayou Choctaw and St. Gabriel domes, and possibly the Bayou Blue dome. Salinization is a

  19. Sources of elevated salinity in the Mississippi River Alluvial Aquifer, south-central Louisiana, USA

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Stephanie E. [Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 (United States); Hanor, Jeffrey S., E-mail: hanor@lsu.edu [Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2011-08-15

    Highlights: > Salinization is impacting groundwater quality in southern Louisiana, USA. > This includes the Mississippi River Alluvial Aquifer. > Geochemical evidence indicates salt dome dissolution is responsible. > Thus, salinization here is a natural, on-going process. > The potential for remediation is slight, if not non-existent. - Abstract: Salinization is a process impacting groundwater quality and availability across much of southern Louisiana, USA. However, a broad divergence of opinion exists regarding the causes of this elevated salinity: updip-migrating marine waters from the Gulf of Mexico, saline fluids migrating up fault planes, movement of water from salt domes, and/or remnant seawater from the last major marine transgression. The Mississippi River Alluvial Aquifer (MRAA) in south-central Louisiana is recharged by the Mississippi River, and there are discharge zones to the west and east. Recharge waters from the Mississippi River are fresh, but Cl{sup -} levels in the western portions of the aquifer are as high as 1000 mg/L. The aquifer is an important source of water for several municipalities and industries, but prior to this study the source(s) of the elevated salinity or whether the salinization can be remediated had not been determined. The low Br/Cl ratios in the groundwaters are consistent with a saline endmember produced by subsurface dissolution of salt domes, not a marine source. The H and O isotopic systematics of the aquifer waters indicate meteoric sources for the H{sub 2}O, not marine waters or diagenetically-altered deep brines. The westward salinization of aquifer water represents a broad regional process, instead of contamination by point sources. Mapping of spatial variations in salinity has permitted the identification of specific salt domes whose subsurface dissolution is producing waters of elevated salinity in the aquifer. These include the Bayou Choctaw and St. Gabriel domes, and possibly the Bayou Blue dome. Salinization is a

  20. Growth and ions (Na/sup +/, K/sup +/ and Cl/sup-1/-) accumulating pattern of some brassica genotypes under saline - sodic field condition

    International Nuclear Information System (INIS)

    The growth and ionic uptake pattern of some Brassica genotypes i.e., Rainbow, Wester, Durr-e-NIFA, Abaseen 95 (Brassica napus) and NIFA raya (Brassica juncea) under saline-sodic field conditions was studied. Two sets of experiments on normal and saline-sodic site were conducted at NIA experimental farm, Tandojam, Pakistan during Rabi 2006-07. The salinity of the experimental site ranged between 11.0-22.9 dS/m and the pH was alkaline (8-8.6). The dominant cation was sodium (Na). The growth performance was recorded at the time of crop harvest in terms of plant height, grain weight / plant, grain yield and 100 grain weight. It was observed that the performance of Wester was better followed by NIFA- raya. The ionic uptake pattern, of leaves, stem and roots showed that the accumulation of Na was less in leaf as compared to stem and roots. However, the genotypes having better performance we re found to have accumulating type of behavior showing comparatively higher Na contents in all plant parts than other genotypes. This suggests that these genotypes might adjust their osmotic potential through the accumulation of sodium in vacuole. On the other hand trend in case of K accumulation was reverse i.e. high in leaves and stem as compared to roots. Higher accumulating pattern of K in leaves might be helpful for reducing the toxic effects of sodium. However, no correlation was observed between K-Na selectivity or K/Na ratio among the genotypes tested. It is therefore concluded that better selective mechanism for Na uptake and strict control of intercellular Na influx for cellular osmotic adjustment could be selected for saline environment. (author)

  1. 15N Isotopic Study on Decomposition of Organic Residues Incorporated into Alluvial and Sandy Saline Soils

    International Nuclear Information System (INIS)

    Incubation experiment was conducted to study the effect of the nitrogenous fertilizer on the decomposition and mineralization of organic residues (soybean powdered forage) as well as the release of the soil inorganic nitrogen. This technique was carried out using two types of soils, one is alluvial and the other is saline sandy soil collected from Fayoum governorate. Soybean forage has an organic carbon 23.1%, total N 1.6% and C/N ratio 14.4. Regarding the effect of incubation period on the two soil samples, the evolved NH4-N was generally reached its highest peak after 30-45 days, in the presence of either the added 15No3-fertilizer solely or in combination with soybean forage. Reversible trend was occurred with regard to the evolved No3-N. The highest peak of evolved No3-N recorded in unfertilized control, as compared to 15No3-N treatment, at 30 day incubation period indicated that the addition of labeled mineral fertilizer had appreciably enhanced the immobilization process. Net nitrification revealed that it was the highest in unfertilized control soil where it was significantly decreased in the treated two soil samples. Gross mineralization as affected by the addition of soybean forage in combination with labeled mineral fertilizer had been promoted by 75% in the alluvial soil and by 18% in the sandy saline soil, as compared with the soil samples received 15No3-fertilizer only. Gross immobilization, in soil samples received 15No3-fertilizer plus soybean forage had surpassed those received 15No3-fertilizer only by 16% in the alluvial soil and by 25% in the sandy saline soil. (Authors)

  2. Impact of defoliation intensities on plant biomass, nutrient uptake and arbuscular mycorrhizal symbiosis in Lotus tenuis growing in a saline-sodic soil.

    Science.gov (United States)

    García, I; Mendoza, R

    2012-11-01

    The impact of different defoliation intensities on the ability of Lotus tenuis plants to regrowth, mobilise nutrients and to associate with native AM fungi and Rhizobium in a saline-sodic soil was investigated. After 70 days, plants were subjected to 0, 25, 50, 75 and 100% defoliation and shoot regrowth was assessed at the end of subsequent 35 days. Compared to non-defoliated plants, low or moderate defoliation up to 75% did not affect shoot regrowth. However, 100% treatment affected shoot regrowth and the clipped plants were not able to compensate the growth attained by non-defoliated plants. Root growth was more affected by defoliation than shoot growth. P and N concentrations in shoots and roots increased with increasing defoliation while Na(+) concentration in shoots of non-defoliated and moderately defoliated plants was similar. Non-defoliated and moderately defoliated plants prevented increases of Na(+) concentration in shoots through both reducing Na(+) uptake and Na(+) transport to shoots by accumulating Na(+) in roots. At high defoliation, the salinity tolerance mechanism is altered and Na(+) concentration in shoots was higher than in roots. Reduction in the photosynthetic capacity induced by defoliation neither changed the root length colonised by AM fungi nor arbuscular colonisation but decreased the vesicular colonisation. Spore density did not change, but hyphal density and Rhizobium nodules increased with defoliation. The strategy of the AM symbiont consists in investing most of the C resources to preferentially retain arbuscular colonisation as well as inoculum density in the soil. PMID:22512871

  3. Bacteria in combination with fertilizers promote root and shoot growth of maize in saline-sodic soil

    OpenAIRE

    Muhammad Zafar-ul-Hye; Hafiz Muhammad Farooq; Mubshar Hussain

    2015-01-01

    Salinity is the leading abiotic stress hampering maize ( Zea mays L.) growth throughout the world, especially in Pakistan. During salinity stress, the endogenous ethylene level in plants increases, which retards proper root growth and consequent shoot growth of the plants. However, certain bacteria contain the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which converts 1-aminocyclopropane-1-carboxylic acid (an immediate precursor of ethylene biosynthesis in higher plants) into am...

  4. Production of methane from kallar grass grown on saline sodic lands: metabolism of carbohydrates, methylated amines and methane precursors during digestion of kallar grass

    International Nuclear Information System (INIS)

    Mesophilic anaerobic digestion of kallar grass on saline sodic land was carried out in batch culture at laboratory scale with enriched culture from biogas plant. Analysis were made to determine biogas volume, gas composition and distribution of volatile fatty acids. The fermentation of kallar grass treated with 2% NaOH showed an increase in digestibility from 20-50% and the conversion efficiency approached 80-95% of theoretical yield which was fold higher than the one obtained from untreated substrates. The contents of methane in bio gas was markedly low during the first day of digestion but increased from 75 to 91% at the end of 20 days retention time. Low pH values (6.2) showed the accumulation of acetic butyric and propionic acids. Addition of carbohydrates, methylated amines and other methane precursors were found to stimulate methanogensis at low concentration (0.1%) carbohydrates, (1mM) methylated amines and methane precursors as compared to their higher concentrations. The phase contrast and fluorescence microscopic examinations showed the diverse microbial population of digestor contents. (author)

  5. Integrated electrokinetics-adsorption remediation of saline-sodic soils: effects of voltage gradient and contaminant concentration on soil electrical conductivity.

    Science.gov (United States)

    Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Lukman, Salihu; Bukhari, Alaadin

    2013-01-01

    In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD) was used for the experimental design and response surface methodology (RSM) was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R (2) ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors. PMID:24459439

  6. Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

    Directory of Open Access Journals (Sweden)

    Mohammed Hussain Essa

    2013-01-01

    Full Text Available In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD was used for the experimental design and response surface methodology (RSM was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R2 ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

  7. Differential response of soil texture for leaching of salts receiving different pore volumes of water in saline-sodic soil column

    International Nuclear Information System (INIS)

    This study examined the leaching requirement of three saline-sodic soils in polyvinyl chloride (PVC) columns of 50 cm long and 11 cm internal diameter. Air-dried soils were packed in PVC lysimeters receiving different pore volume (PV) of water (EC 0.89 dS m/sup -1/, SAR 1.55, RSC 1.02 mmolc L/sup -1). Leaching with 2.5 PV of water removed 94 % of soluble salts and decreased EC/sub e/from 33.9 to 5.9 dS m/sup -1/ in 0-25 cm layer of sandy clay loam soil. For lowering EC/sub e/ to < 4 dS m/sup -1/ in loamy sand up to 0-25 cm soil layer, 2.0 PV water removed 67 % soluble salts. In silty clay loam soil, 2.5 PV water lowered EC/sub e/ to < 4 dS m/sup -1/only up to 0-10 cm depth with 83 % removal of salts. Relationships between EC/EC 0 and D w/Ds established were for the soils as EC/EC/sub 0/ = 0.329 (D w/D/sub S/)/sup -2.12/ with r= 0.87 for loamy sand; EC/EC/sub 0/ = 0.16sub -0.60/ with r=0.89 for silty clay loam and EC/EC/sub 0/sup = 0.06/ (Dw/D/sub s/)/sup 0.78/ with r=0.98 for sandy clay loam soil. These relationships leads to conclude that reduction in salinity of loamy sand, silty clay loam and sandy clay loam soil was 67, 83 and 94 % when leached with 1.88, 2.72 and 2.67 cm of water, respectively. (author)

  8. Assessing Leaching of Saline-sodic Soils Affected by Kaveh-Soda Factory Effluent using Georeferenced Maps in Maragheh-Bonab Plain

    Directory of Open Access Journals (Sweden)

    Farzin Shahbazi

    2015-12-01

    Full Text Available Relativity of soil maps may limit their utility at many aspects such as agriculture development, farming, civil engineering, urban and regional planning and forestry. Paying attention to the scale is one of the most common procedures in assessing the maps usability. The average size delineation (ASD, effective scale number (ESN, index of maximum reduction (IMR and shape complexity index (SCI are the maps quality criteria that can be examined. The purposes of this study were: a to evaluate the EC and SAR maps of the farm lands affected by the Kaveh-Soda factory effluent on the basis of the above quality criteria and b to evaluate the efficiency of continuous and intermittent methods of leaching in three Saline-Sodic soils with loam and sandy loam textures. EC maps of the area were selected and ASD, ESN, IMR and SCI were determined as 0.95 cm2, 1:26000, 1.54 and 3.33, respectively. For the SAR maps the above criteria were 1.33 cm2, 1:31000, 1.84 and 3.51, respectively. According to the above criteria there should be no limitation in their uses for developing of agricultural and civil engineering projects. It is known that optimum IMR is equal to 2, so that raising IMR of EC and SAR maps from 1.54 and 1.84 to 2 led their scale to increase from 1:34000 to 1:26000 and 1:31000, respectively and increase maps contrast as well. At the subsequent stage, efficiency of two leaching methods of saline-sodic soils was examined after knowing the usability of the maps and separating their units, as affected by Kaveh-Soda factory (Maragheh. For this purpose, PVC tubes (Lengths= 70 cm; Diameter= 10 cm were prepared and filled with soil (5200 g sieved by 4.76 mm. The flow rate during both leaching methods was selected to be 1.25 KS of the columns. Soil columns were grouped according their EC as 1 EC= 10.38 dSm-1, with Na+= 49.64 meqL-1; 2 EC= 20.6 dSm-1, with Na+= 94.57 meqL-1; and 3 EC= 36.6 dSm-1, with Na+ = 166.11 meqL-1. Leaching water was saturated with

  9. Influence of Irrigation Water Discharge Frequency on Soil Salt Removal and Rice Yield in a Semi-Arid and Saline-Sodic Area

    Directory of Open Access Journals (Sweden)

    Zhigang Huang

    2013-05-01

    Full Text Available Irrigation practice for rice culture can be especially challenging in areas with limited water supply and soil salinization. In this study, we carried out a field experiment to assess the effects of different water discharge frequencies on soil salt content, rice yield and water use efficiency on a saline-sodic soil in a semi-arid region of Northeast China. The experiment comprised of three frequency levels of discharge [9-time (I-9-30, 6-time (I-6-30 and 3-time (I-3-30 discharge, all followed with a 30-mm irrigation] in comparison with the traditional irrigation practice of 2-time discharge followed with an 80-mm irrigation (I-2-80. Our initial hypothesis was that increasing discharge frequency would increase both salt reduction and rice yield. Daily precipitation was recorded by a nearby weather station, and evapotranspiration and soil water percolation rates were measured at experimental sites using soil pits. The measurements were used to establish a water balance for each treatment. Our results showed that soil salt reduction increased with the increasing discharge frequency at a 30-mm irrigation water depth. The 9-time discharge reduced a large amount of soil salt (995.0 kg ha−1 after five months of the study. Rice yield also increased with the increasing discharge frequency with a 30-mm irrigation water depth; however, when compared to the traditional 2-time discharge followed with an 80-mm irrigation, rice yield at the sites with more frequent discharge (i.e., I-9-30, I-6-30 and I-3-30 was 11%–18% lower. Because of this, rice yield and irrigation water use efficiency were significantly higher under the traditional practice of high-irrigation with low-frequency discharge (I-2-80 than under I-9-30, I-6-30 and I-3-30. These results indicate a need for a trade-off amongst salt reduction, rice yield and water use when considering selection of irrigation and discharge schedules.

  10. 冬季结冰灌溉对苏打盐碱土水盐变化的影响%Effect of Freezing Water Irrigation on the Changes of Soil Water and Salt in Saline-Sodic Soil Area

    Institute of Scientific and Technical Information of China (English)

    杨帆; 王志春; 肖烨

    2012-01-01

    A field experiment was conducted to investigate the water and salt dynamic of saline-sodic soil with freezing water irrigation in winter in Songnen Plain of China,which is one of the largest saline-sodic areas in the world.The plots were designed as follows: freezing saline water irrigation with application of phosphogypsum(100%GR gypsum requirement)(A),freezing saline water irrigation with application of phosphogypsum(50% GR)(B),freezing fresh water irrigation(C),freezing saline water irrigation(D),no irrigation and no phosphogypsum as CK.A total of 180 mm water was applied to experimental plots in January of 2011.Results showed that melted ice water increased soil water content in topsoil layer.It has great significance for resisting drought in spring planting.With infiltration of melted ice water,the surface soil was significantly desalinized.Major ions including Na+、Cl-、CO32-、HCO3-were decreasing by melted ice water.Comparative analysis demonstrated that desalinized effect was better in freezing saline water irrigation than freezing fresh water irrigation,and desalinized effect was better in freezing saline water irrigation with application of phosphogypsum than freezing saline water irrigation,and with the increase of phosphogypsum,soil desalinized effect was higher.The results indicated that the approach of freezing saline water irrigation and phosphogypsum in winter may benefit to resist drought in spring planting and improve saline-sodic soil by use of local saline groundwater.%在苏打盐碱土区进行结冰灌溉试验,研究灌溉后盐碱土土壤水分和盐分的分布状况。试验分为淡水结冰灌溉(E)、微咸水结冰灌溉(D)、微咸水结冰灌溉+100%GR(石膏需求量)磷石膏(A),微咸水结冰灌溉+50%GR磷石膏(B),以及对照(CK),5个处理。灌溉水量为180 mm。试验结果表明灌溉融水增加了土壤耕层的含水量,为春播抗旱起到了重要作用。同时灌溉融水使土

  11. 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.

  12. Optimal control solutions to sodic soil reclamation

    Science.gov (United States)

    Mau, Yair; Porporato, Amilcare

    2016-05-01

    We study the reclamation process of a sodic soil by irrigation with water amended with calcium cations. In order to explore the entire range of time-dependent strategies, this task is framed as an optimal control problem, where the amendment rate is the control and the total rehabilitation time is the quantity to be minimized. We use a minimalist model of vertically averaged soil salinity and sodicity, in which the main feedback controlling the dynamics is the nonlinear coupling of soil water and exchange complex, given by the Gapon equation. We show that the optimal solution is a bang-bang control strategy, where the amendment rate is discontinuously switched along the process from a maximum value to zero. The solution enables a reduction in remediation time of about 50%, compared with the continuous use of good-quality irrigation water. Because of its general structure, the bang-bang solution is also shown to work for the reclamation of other soil conditions, such as saline-sodic soils. The novelty in our modeling approach is the capability of searching the entire "strategy space" for optimal time-dependent protocols. The optimal solutions found for the minimalist model can be then fine-tuned by experiments and numerical simulations, applicable to realistic conditions that include spatial variability and heterogeneities.

  13. 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

    the salinity and sodicity variability, constituting a tool for the definition of soil management and reclamation of the affected area. Key words: salinization, exchangeable sodium percentage, geostatistics

  14. Grazing as an alternative for utilization of saline-sodic soils in the San Joaquin Valley: Selenium accretion and performance of beef heifers

    International Nuclear Information System (INIS)

    Two experiments were conducted to evaluate Se accumulation and health of non-pregnant, non-breeding beef cattle grazing on forages with a high Se content due to irrigation with saline drainage water. Heifers grazed experimental pastures of “Jose” tall wheatgrass (TWG; Thinopyrum ponticum var. “Jose”) and creeping wildrye (CWR; Leymus triticoides var. “Rio”) for190 days in Experiment 1 (2007) and for 165 days in Experiment 2 (2008). In experiment 1, mean Se concentrations were similar in TWG and CWR herbage (4.0 versus 3.7 ± 0.26 mg/kg dry weight; p = 0.34) as was crude protein (113 versus 114 ± 7.9 g/kg dry weight; p = 0.94). Concentrations of Se in blood increased by 300% during the grazing period, and were similar for heifers grazing the TWG or CWR pastures (0.94 versus 0.87 ± 0.03 mg/kg; p = 0.89). Heifers grazing on TWG gained more body weight than did heifers grazing on CWR (0.59 versus 0.27 ± 0.07 kg/days; p < 0.01). In experiment 2, concentration of Se (4.0 versus 2.8 mg/kg ± 0.19 mg/kg dry weight; p < 0.01) and crude protein (79 versus 90 ± 5.6 g/kg dry weight; p < 0.01) differed, for TWG and CWR, respectively. Within 20 days, Se concentrations in blood had increased by 300% and by nearly 200% in heifers grazing on TWG or CWR. All data cited are least square means ± standard error of the mean. Data from our two grazing seasons are consistent in demonstrating the safety of grazing beef cattle for a period of up to 6 months on TWG and CWR forages having high levels of Se due to irrigation with saline drainage water. This suggests that forage production using saline drainage water is a viable alternative for saline soils with limited potential for producing high value, salt-sensitive, crops. - Highlights: ► Forages irrigated with saline drainage water may contain high levels of selenium. ► High concentration of selenium in forages can be toxic to grazing cattle. ► Cattle accumulated high levels of selenium in blood, liver and muscle

  15. Sodicity Properties of Saline Fluvo-aquic Soils around Wuliangsuhai Lake%乌梁素海周围盐化潮土钠质化特征

    Institute of Scientific and Technical Information of China (English)

    刘骏; 于会彬; 谢森; 席北斗; 蒋进元

    2011-01-01

    Sixteen composite soil samples from different depths (0-20 cm, >20-40 cm, >40-60 cm and >60-80 cm) were collected from four different halophyte communities, namely, Comm. Salicornia europaea (CSE), Comm. Suaeda glauca (CSG),Comm. Kalidium foliatum (CKF) and Comm. Sophora alopecuroides (CSA) located around Wuliangsuhai Lake. Based on measuring exchangeable sodium ion percentage (ESP), sodium absorption rate (SAR), pH, moisture and salinity, the salinization properties of saline fluvo-aquic soils were analyzed. The results showed that the means of salinity, ESP and SAR in CSE profile were highest, followed by CSG, CKF and CSA. The total contents of metal ions were highest in CSE profile, followed by CSG,CKF and CSA. The major cations were Ca2+ and Na+, while the major anions were C1 - and SO42- , though the contents of CO32 and HCO3 - were less. Chloride and sulphate were the main soil salinity, and carbonate existed as calcium carbonate. ESP was significantly and positively correlated with salinity ( R2 = 0. 834, P = 0. 0008 ) and SAR ( R2 = 0. 862, P = 0. 0002 ), indicating that ESP increases with the rise of salinity and SAR, and SAR can be used as a surrogate for ESP. The distribution of salts in soil profiles is formed from the combined effect of precipitation, evaporation, irrigation, groundwater, etc.%以乌梁素海周围盐角草(CSE)、碱蓬(CSG)、盐爪爪(CKF)和苦豆子(CSA)群落的盐化潮土为研究对象,分别采集0~20,>20~40,>40~60和>60~80 cm共16个混合土样.测定土壤pH,含水量,含盐量,钠吸附比(SAR)和交换性钠离子百分率(ESP)等指标,分析了土壤的碱化特征.结果表明:CSE土壤剖面含盐量,SAR和ESP的平均值最高,其次为CSG,CKF和CSA土壤.CSE土壤金属离子总量最大,其次为CSG,CKF和CSA;阳离子以Ca2+和Na+为主,阴离子以Cl-和SO2-4为主,而CO32-和HCO3-含量极低.土壤盐分主要以氯化物和硫酸盐为主,碳酸盐以碳酸钙形式存在.ESP与含盐量(R2

  16. Fitoextração de sais pela Atriplex nummularia lindl. sob estresse hídrico em solo salino sódico Phytoextraction of salts by Atriplex nummularia lindl. under water stress in saline sodic soils

    Directory of Open Access Journals (Sweden)

    Edivan R. de Souza

    2011-05-01

    Full Text Available Objetivou-se avaliar a extração de sais pela Atriplex cultivada em solo salino sódico sob condições de estresse hídrico e comparar propriedades do solo antes e após seu cultivo. O experimento foi desenvolvido em casa de vegetação durante 134 dias, com cultivo em vasos com 20 kg de solo salino sódico em quatro níveis de umidade (35, 55, 75 e 95% da capacidade de campo, com um tratamento controle (sem cultivo, montado em blocos casualizados, com oito repetições. As altas concentrações de Ca2+, Mg2+, K+ e, especialmente Na+ e Cl- nas folhas de Atriplex nummularia, associadas à elevada produção de massa seca, caracterizam esta espécie como planta fitoextratora de sais, chegando a extrair, nas folhas e caule, o equivalente a: 644,25; 757,81; 1.058,55 e 1.182,00 kg ha-1 desses elementos, para 35, 55, 75 e 95% da capacidade de campo, respectivamente. As variáveis do complexo sortivo do solo (Ca2+, Mg2+, K+, soma de bases e o carbono orgânico total, permaneceram estáveis entre o início e o final do experimento, em todos os tratamentos, enquanto o Na+ e a percentagem de sódio trocável diminuíram após o cultivo da planta. A Atriplex respondeu ao incremento de umidade do solo quando se considera a produção de biomassa e a extração de sais.This study aims to evaluate the growth, production and extraction of salts by Atriplex grown on saline-sodic soil under water stress conditions and to compare soil properties before and after their cultivation. The experiment was carried out in a greenhouse during 134 days growing Atriplex nummularia in pots with 20 kg of saline sodic soil with four levels of soil moisture (35, 55, 75 and 95% of field capacity with a control (soil without plant. The experiment was performed in a randomized block with eight replications. The high concentrations of Ca2+, Mg2+, K+, and especially Na+ and Cl- in leaves of Atriplex nummularia, associated with high dry matter production characterizes this species

  17. Atividade biológica em solo salino sódico saturado por água sob cultivo de Atriplex nummularia Biological activity in saline sodic soil saturated by water under cultivation of Atriplex nummularia

    Directory of Open Access Journals (Sweden)

    Karen Cristina Fialho dos Santos

    2011-09-01

    ./ Therefore, the aim of this study was to assess the microbial activity in saline sodic soil of the Agreste of Pernambuco, in the presence and absence of plants of Atriplex nummularia./ For that, there were samples of soil to 20 cm depth in different situations: 1 and 2 in the proximity of roots (20 cm from the stem of each plant in treatments with and without pruning, 3 and 4 at the midpoint of plant spacing (125 cm in treatments with and without pruning, 5 bare soil (control treatment, in the rainy season./ These samples were analyzed for C and N microbial biomass, basal respiration and C and N content of soils./ It was observed that the control treatment had different results compared with other treatments, indicating that without plants of atriplex the soil microbiota is highly affected by the high salt concentrations. There was also a tendency for increased microbial activity with proximity of pruned plant roots of atriplex, showing that, besides being a viable plant for phytoremediation of salinized soils, still promotes an improvement of soil microbes.

  18. Fitorremediação de solo salino s ódico por Atriplex nummularia e gesso de jazida Use of Atriplex nummularia and gypsum for phytoremediation of saline-sodic soil

    Directory of Open Access Journals (Sweden)

    Isaac Gomes Leal

    2008-06-01

    Full Text Available Atriplex nummularia apresenta-se como alternativa de uso na recuperação de solos salino-sódicos, podendo servir como suporte forrageiro e como folhagem na floricultura e paisagismo. Com o objetivo de avaliar o potencial desta halófita na fitorremediação de solo salino-sódico sob irrigação com águas salinas e verificar o potencial do gesso como potencializador da fitoextração de Na, realizou-se um experimento em casa de vegetação, em esquema fatorial 2 x 3, sendo dois tratamentos com gesso de jazida(ausência, e aplicação de 50 % da dose recomendada pela necessidade de gesso e três classes de água para irrigação (C1 = 175 μS cm-1; C2 = 500 μS cm-1e C3 = 1500 μS cm-1. Foram realizadas avaliações dos teores de Na, no solo e na planta, aos 40, 70, 100 e 130 dias do transplantio da A. nummularia. O gesso proporcionou ganho médio de 96 % na matéria seca de raiz. O teor de Na nas folhas foi significativo a partir da terceira época avaliada com valores de 90,1 e 109,7 g kg-1, para 100 e 130 dias após o transplantio, respectivamente. Este efeito foi aumentado em 30 % com a aplicação de gesso. O teor de Na+ no solo foi menor em média 31 e 26 %, com e sem gesso, respectivamente, a partir de 100 dias após o transplantio. Com base nas condições estudadas, pode-se concluir que a Atriplex nummularia comportou-se como planta hiperacumuladora de Na, com potencial de uso na fitoextração deste elemento no solo. O uso do gesso de jazida promoveu o aumento da capacidade de extração de Na do solo pela planta, podendo ser usado como potencializador da fitoextração. A irrigação da A. nummularia para uso de fitorremediação pode ser feita com águas salinas na faixa de 175 a 1500 μS cm-1.The cultivation of Atriplex nummularia on saline-sodic soils is economically attractive because it can be used as a forage crop as well as in landscape projects. The potential of Atriplex nummularia for phytoextraction of Na+ from a saline-sodic

  19. Melhorias nas propriedades químicas de um solo salino-sódico e rendimento de arroz, sob diferentes tratamentos Improvement in chemical properties of saline-sodic soil and rice yield under under different treatments

    Directory of Open Access Journals (Sweden)

    Everaldo Mariano Gomes

    2000-12-01

    Full Text Available Instalou-se um experimento num solo salino-sódico no Perímetro Irrigado de São Gonçalo, com o objetivo de se avaliar o efeito de diferentes produtos condicionadores nas propriedades químicas do solo e seus reflexos nos componentes de produção e rendimento de grãos na cultura de arroz irrigado (Oryza sativa L.. O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e cinco repetições. Os tratamentos estudados foram: gesso (20 Mg ha-1; casca de arroz (15 Mg ha-1; testemunha; vinhaça (40 m³ ha-1 e esterco de curral (40 Mg ha-1. Após aplicação dos tratamentos, o solo foi lixiviado durante 40 dias, mantendo uma lâmina de 8 cm de água nas parcelas. Os tratamentos mostraram efeitos positivos nas propriedades químicas do solo (percentagem de sódio trocável, condutividade elétrica do extrato de saturação e pH da pasta saturada sendo que o esterco de curral e gesso proporcionaram apreciáveis decréscimos em comparação aos outros tratamentos; entretanto, os produtos utilizados não mostraram efeitos significativos no número de panículas, peso de panículas e rendimento do arroz.An experiment was installed in a saline-sodic soil of the Irrigated Perimeter of São Gonçalo, with the objective of evaluating the effect of different amendments in the chemical properties of soil and its posterior reflexes in the components of production and grain yield of irrigated rice (Oryza sativa L.. The experiment consisted of five treatments with five replications in a completely randomized design. The treatments studied were: gypsum (20 Mg ha-1; rice husk (15 Mg ha-1; control; stillage (40 m³ ha-1 and farmyard manure (40 Mg ha-1. After incorporation of amendments, the soil was leached for 40 days, keeping an 8 cm depth of water in the plots. The treatments showed positive effects in the chemical properties of the soil (exchangeable sodium percentage, electrical conductivity of saturation extract and pH of saturation

  20. 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...

  1. Hydrochemical evolution within a large alluvial groundwater resource overlying a shallow coal seam gas reservoir.

    Science.gov (United States)

    Owen, Daniel D R; Cox, Malcolm E

    2015-08-01

    A combination of multivariate statistical techniques, simple hydrochemical mixing models and inverse geochemical modelling was used to investigate the major hydrochemical evolutionary pathways of a large alluvial aquifer, the upper Condamine River alluvium, south-east Queensland, Australia. Hydrochemical similarities between alluvium and sedimentary bedrock groundwater imply some mixing between alluvial and sedimentary bedrock aquifers, but spatial assessment showed that this was localised around outcrops of sedimentary bedrock in upstream areas. Within the alluvium, a distinct shift towards a low salinity Na-HCO3 water type and a brackish Na-HCO3-Cl water type was obvious in two separate locations. Both of these water types are unique to the alluvium, and inverse modelling shows that they can evolve via a combination of in situ alluvial processes, including diffuse recharge of rainfall or river water or the evolution of basalt-derived groundwater via gypsum dissolution plagioclase weathering, cation exchange and some carbonate precipitation/dissolution. The evolution of these water types is potentially influenced by overlying sodic alkaline soils, and often is associated with a source of sulfate. Evapotranspiration is the dominant salinization process in the alluvium and increases in calcium cations during salinization indicate that brackish Na-HCO3-Cl groundwater in the underlying Walloon Coal Measures are unlikely to have a major influence on salinization in the alluvium. The most saline water types observed were endemic to shallow zones of the alluvium where evapotranspiration is likely. Results demonstrate that a combination of multivariate statistics and inverse geochemical modelling can be successfully used to delineate hydrochemical pathways in complex hydrogeological settings where a range of environmental and anthropogenic factors may be influencing the evolution of water types with similar hydrochemical compositions. PMID:25863513

  2. Comportamento de atributos químicos de um solo salino-sódico tratado com gesso e fósforo Behavior of chemical parameters of a saline sodic soil treated with gypsum and phosphorus

    Directory of Open Access Journals (Sweden)

    Adriana de F. M. Vital

    2005-03-01

    Full Text Available Os solos degradados por sais e sódio, comuns nas áreas irrigadas da região semi-árida, apresentam atributos físicos e químicos desfavoráveis à agricultura. A baixa disponibilidade de nutrientes, como o fósforo, nesses solos é uma realidade. Desta forma o emprego de corretivos e o estudo da disponibilidade de fósforo nessas áreas constituem-se numa alternativa para reintegrar tais solos à produção agrícola. Conduziu-se um experimento para verificar o efeito da aplicação de quatro níveis de gesso (0, 50, 100 e 200% da necessidade do gesso e quatro dosagens de fósforo (0, 150, 300 e 450 mg dm-3, em solo salino-sódico (Cambissolo - CE 4,2 dS m-1, PST 52, pH 6,3 e CaCO3 65 g kg-1 de textura franco-argilosa (areia 18,8%, silte 43,9% e argila 37,3%, do Perímetro Irrigado de Capoeira - São José do Bonfim, PB. Analisaram-se os parâmetros fósforo disponível, Na, Ca, Mg, pH, PST e CE, cujos dados revelaram que o corretivo exerceu efeito significativo no aumento de cálcio e fósforo do solo e na redução da PST e pH. A aplicação de gesso e fósforo promoveu aumento significativo nos teores de P do solo e redução do Na. Para as demais variáveis, o efeito dos tratamentos foi não significativo.The soils degraded by salts and sodium, common in the irrigated areas of the semi-arid region, present physical and chemical attributes unfavorable for the agriculture. The low availability of nutrients, like phosphorus, in these soils is a reality, therefore, employment of amendments and the study of availability of phosphorus in these areas constitute an alternative to reintegrate such soils to the agricultural production. An experiment was installed in a greenhouse to verify the effects of four levels of gypsum (0, 50, 100 and 200% of gypsum requirement and phosphorus (0, 150, 300 and 450 mg kg-1, in a saline-sodic soil (Cambisol, EC 4.2 dS m-1; ESP 52, pH 6.3 and CaCO3 65 g kg-1 of clay loam texture (sand 18,8%, silt 43,9% and loam

  3. Geohydrology of the Wellington-alluvial aquifer system and evaluation of possible locations of relief wells to decrease saline ground-water discharge to the Smoky Hill and Solomon rivers, central Kansas

    Science.gov (United States)

    Gillespie, Joe B.; Hargadine, G.D.

    1986-01-01

    Saline water discharges from the alluvial aquifer into the Smoky Hill and Solomon Rivers between New Cambria and Solomon in central Kansas. Chloride concentrations in the Smoky Hill River sometimes exceed 1,000 mg/L during low flow conditions. The source of saline water is the underlying Wellington aquifer, a zone of halite and gypsum dissolution, subsidence, and collapse along the eastern margin of the Permian Hutchinson Salt Member of the Wellington Formation. Locally, brine from the Wellington aquifer flows upward through collapse structures in the confining layer into the overlying alluvium. Estimated brine discharge averages about 0.8 cu ft/sec. Control of the saline groundwater discharge to the Smoky Hill and Solomon Rivers is desirable to improve the quality of water in the rivers. The upward discharge of natural brine into the alluvium could be partly controlled by relief wells installed in the Wellington aquifer. The wells need to be located in the area of greatest saline groundwater discharge to the rivers and near the eastern end of the Wellington aquifer between New Cambria and Solomon. The relief wells could be pumped just enough to reverse the hydraulic gradient between the Wellington and alluvial aquifers, decreasing the upward flow of brine into the alluvium and, into the rivers. The brine could be disposed into brine aquifers underlying the area at depth or pumped into surface evaporation-storage reservoirs. (Author 's abstract)

  4. Dinâmica de íons em solo salino-sódico sob fitorremediação com Atriplex nummularia e aplicação de gesso Dynamics of ions in saline-sodic soil under phytoremediation with Atriplex nummularia and gypsum applications

    Directory of Open Access Journals (Sweden)

    Monaliza A. dos Santos

    2013-04-01

    Full Text Available Desenvolveu-se este trabalho em um Cambissolo salino sódico do Perímetro Irrigado Cachoeira II, Serra Talhada, PE, com o objetivo de avaliar a dinâmica de cátions e ânions básicos em um solo salino sódico submetido a fitorremediação com Atriplex nummularia e correção com aplicação de gesso. Realizaram-se amostragens semestrais com quatro coletas de solo (0, 6, 12 e 18 meses. O delineamento experimental utilizado foi de blocos ao acaso avaliando-se quatro tratamentos: controle (sem nenhum manejo do solo, correção química com gesso (sem cultivo e dois com cultivo de Atriplex nummularia Lindl (espaçamentos 1 x 1 m e 2 x 2 m, com quatro repetições. Os resultados das análises do solo revelaram a contribuição da aplicação de gesso, especialmente do cultivo de plantas de atriplex na redução dos teores de sais no solo.The study was conducted in a saline-sodic Inceptisol from the Cachoeira II Irrigation Perimeter, Serra Talhada (PE, with the objective of evaluating the dynamics of basic cations and anions in a saline-sodic soil subjected to phytoremediation with Atriplex nummularia and correction with application of gypsum. Samples were taken every six months, at four times (0, 6, 12 and 18 months. The experimental design was in randomized blocks, the four Treatments evaluated were: control (without any management practice, chemical correction with gypsum (no crop and two Atriplex nummularia cultivation (1 x 1 m and 2 x 2 m plant spacing, with four replications. The results of soil analysis revealed the contribution of gypsum application and especially the cultivation of Atriplex plants in reducing the levels of salts in the soil.

  5. 干旱区盐碱地覆膜滴灌不同年限对糯玉米生长和产量的影响%Effects of Different Irrigation and Cropping Years on Waxy Corn Growth and Yield Using Drip Irrigation with Plastic-Film Mulching on Saline-Sodic Soils in Arid Area

    Institute of Scientific and Technical Information of China (English)

    谭军利; 康跃虎; 窦超银

    2013-01-01

    [Objective]Soil environment had changed greatly during the reclamation of saline-sodic soils with drip irrigation technology. Crop growth is the comprehensively reflection of this change. In this paper, the response of waxy corn growth and yield to changes of soil environment during the reclamation process of saline-sodic soils was investigated.[Method]Through the method of field experiment, the emergency rate, height, the stem perimeter, the dry biomass, the yield of waxy corn and irrigation water use efficiency in the fields of reclaimed and drip irrigated for 1 year, 2 years, 3 years and 4 years were determined and the response mechanism of waxy corn to soil environment changes was investigated. [Result]Results showed that using the irrigation method that irrigated about 30 mm water at first time after crop sowing and then used tensiometer, which was buried at 0.2 m depth immediately under drip emitter, to control soil matric potential higher than-10 kPa could guarantee emergence rate above 90%and high yield of waxy corn. Even in the field with drip-irrigation and cropped in the first year.The height, the stem perimeter, the dry biomass, the yield of waxy corn and irrigation water use efficiency increased with the increase of irrigation and cropping years. There was a significant difference in these indexes among different irrigation and cropping years during the corn growth period. In addition, the growth rhythm of waxy corn in different treatments had significant differences also. [Conclusion]Application of drip irrigation and cropping technology introduced in this paper for reclaimation of saline-sodic soils, soil environments changed greatly with the increase of the irrigation and cropping years. The changes of saline-sodic soils were reflected by the growth index and yield of waxy corn.%[目的]探讨糯玉米生长及产量对盐碱地改良过程中土壤环境变化的响应,以期为干旱区利用覆膜滴灌技术可持续利用盐碱地提供理

  6. Modeling Soil Sodicity Problems under Dryland and Irrigated Conditions: Case Studies in Argentina and Colombia

    Science.gov (United States)

    Pla-Sentís, Ildefonso

    2014-05-01

    Salt-affected soils, both saline and sodic, my develop both under dryland and irrigated conditions, affecting negatively the physical and chemical soil properties, the crop production and the animal and human health.Among the development processes of salt-affected soils, the processes of sodification have been generally received less attention and is less understood than the development of saline soils. Although in both of them, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. In this contribution we present two case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dryland conditions and sub-humid temperate climate, with pastures for cattle production; the other deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production. In both cases the development of sodicity in the surface soil is mainly related to the effects of the composition and level of groundwater, affected in the case of Argentina Pampas by the off-site changes in dryland use and management in the upper zones and by the drainage conditions in the lowlands, and in the case of the Cauca Valley, by the on-site irrigation and drainage management in lands with sugarcane. There is shown how the model SALSODIMAR, developed by the main author, based on the balance of water and soluble componentes of both the irrigation water and groundwater under different water and land management conditions, may be adapted for the diagnosis and prediction of both problems, and for the selection of alternatives for their management and amelioration.

  7. 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

  8. Sodic soil properties and sunflower growth as affected by byproducts of flue gas desulfurization.

    Directory of Open Access Journals (Sweden)

    Jinman Wang

    Full Text Available The main component of the byproducts of flue gas desulfurization (BFGD is CaSO(4, which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha(-1 and two leaching levels (750 and 1200 m(3 ha(-1. The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP, pH and total dissolved salts (TDS in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha(-1 and water was supplied at 1200 m(3·ha(-1. Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage.

  9. Effect of Soil Matric Potential on Poplar Growth and Distribution of Soil Salt under Drip Irrigation in Saline-sodic Soil in Aarid Regions%盐碱地滴灌对新疆杨生长及土壤盐分分布影响

    Institute of Scientific and Technical Information of China (English)

    王若水; 康跃虎; 万书勤; 胡伟; 刘士平

    2012-01-01

    Field experiments were conducted to investigate the effects of soil matric potential under ridge-mulch drip irrigation on poplar growth and soil salt distribution in saline soil land.The experiment included five treatments,in which controlled the soil matric potential higher than-5 kPa(S1),-10 kPa(S2),-15 kPa(S3),-20 kPa(S4) and-25 kPa(S5),respectively.All treatments were repeated three times with the experimental plots following a complete randomized block design.Results showed that after the first irrigation season,the root zone soil salinity in the whole soil profile decreased by 67% compared with that before transplanting.Different irrigation regimes applied in the second year and soil salinity content were different for each treatment.Due to more amount of irrigation water applied in S1(-5 kPa) and S2(-10 kPa) treatments,more soil salt was leached effectively than that in other treatments and the root zone salt salinity decreased by 79% compared with that before transplanting.Owing to less amount of irrigation water applied in S5 treatment,more soil salt rose with the decreasing of soil depth than those in the other treatments and the soil salinity increased dramatically when the soil depth was below 40 cm.After two years growth,the survival rate of each treatment was kept above 92%.Additionally,the increased amount of poplar DBH rose with the increasing amount of irrigation water.The research results have a theory and application value for the water and soil salt regulation and poplar irrigation scheduling on saline-sodic land.%通过田间试验研究高垄覆膜滴灌模式下不同土壤基质势对盐碱地新疆杨生长以及土壤盐分分布的影响。试验设5个水平的土壤基质势处理:-5kPa(S1),-10kPa(S2),-15kPa(S3),-20kPa(S4),-25kPa(S5),每个处理重复3次,按随机区组布置。试验结果表明,2009年生育末期,根系周围土体中的盐分比移栽前土壤中的盐分减小了67%,

  10. 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...

  11. 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

  12. Learning from the Past : India Uttar Pradesh Sodic Lands Reclamation Project

    OpenAIRE

    Kuehnast, Kathleen

    2001-01-01

    India's Uttar Pradesh Sodic Lands Reclamation Project has two objectives. First, it seeks to reverse the decline of productivity through sustainable reclamation of sodic lands. Second, it is intended to prevent additional increases in sodicity through strengthening local institutions and enabling effective management of such programs with strong beneficiary participation and nongovernmenta...

  13. Modeling for conjuctive use irrigation planning in sodic groundwater areas

    NARCIS (Netherlands)

    Kaledhonkar, M.J.; Sharma, D.R.; Tyagi, N.K.; Kumar, A.; Zee, van der S.E.A.T.M.

    2012-01-01

    Prevalent irrigation water quality guidelines for use of sodic groundwater on sandy loam soils of Haryana for kharif (monsoon) fallow–rabi (winter) wheat crop rotation were investigated through modeling with UNSATCHEM. Three sandy loam soils that vary with respect to soil CEC (Cation Exchange Capaci

  14. Mapping soil salinity in irrigated land using optical remote sensing data

    OpenAIRE

    Rachid Lhissoui; Abderrazak El Harti; Karem Chokmani

    2014-01-01

    Soil salinity caused by natural or human-induced processes is certainly a severe environmental problem that already affects 400 million hectares and seriously threatens an equivalent surface. Salinization causes negative effects on the ground; it affects agricultural production, infrastructure, water resources and biodiversity. In semi-arid and arid areas, 21% of irrigated lands suffer from waterlogging, salinity and/or sodicity that reduce their yields. 77 million hectares are saline soils i...

  15. 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...

  16. The effect of chemical and organic amendments on sodium exchange equilibria in a calcareous sodic soil.

    Science.gov (United States)

    Ranjbar, Faranak; Jalali, Mohsen

    2015-11-01

    In this study, the reclamation of a calcareous sodic soil with the exchangeable sodium percentage (ESP) value of 26.6% was investigated using the cheap and readily available chemical and organic materials including natural bentonite and zeolite saturated with calcium (Ca2+), waste calcite, three metal oxide nanoparticles functionalized with an acidic extract of potato residues, and potato residues. Chemical amendments were added to the soil at a rate of 2%, while potato residues were applied at the rates of 2 and 4% by weight. The ESP in the amended soils was reduced in the range of 0.9-4.9% compared to the control soil, and the smallest and the largest decline was respectively observed in treatments containing waste calcite and 4% of potato residues. Despite the reduction in ESP, the values of this parameter were not below 15% at the end of a 40-day incubation period. So, the effect of solutions of varying sodium adsorption ratio (SAR) values of 0, 5, 10, 20, 30, 40, and 50 on sodium (Na+) exchange equilibria was evaluated in batch systems. The empirical models (simple linear, Temkin, and Dubinin-Radushkevich) fitted well to experimental data. The relations of quantity to intensity (Q/I) revealed that the potential buffering capacity for Na+ (PBCNa) varied from 0.275 to 0.337 ((cmolc kg(-1)) (mmol L(-1))(-1/2)) in the control soil and amended soils. The relationship between exchangeable sodium ratio (ESR) and SAR was individually determined for the control soil and amended soils. The values of Gapon selectivity coefficient (KG) of Na+ differed from the value suggested by U.S. Salinity Laboratory (USSL). The PHREEQC, a geochemical computer program, was applied to simulate Na+ exchange isotherms by using the mechanistic cation exchange model (CEM) along with Gaines-Thomas selectivity coefficients. The simulation results indicated that Na+ exchange isotherms and Q/I and ESR-SAR relations were influenced by the type of counter anions. The values of K G increased in

  17. Effect of Byproducts of Flue Gas Desulfurization on the Soluble Salts Composition and Chemical Properties of Sodic Soils

    OpenAIRE

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2013-01-01

    The byproducts of flue gas desulfurization (BFGD) are a useful external source of Ca2+ for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two...

  18. Salinization and Saline Environments

    Science.gov (United States)

    Vengosh, A.

    2003-12-01

    One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

  19. Effect of byproducts of flue gas desulfurization on the soluble salts composition and chemical properties of sodic soils.

    Directory of Open Access Journals (Sweden)

    Jinman Wang

    Full Text Available The byproducts of flue gas desulfurization (BFGD are a useful external source of Ca(2+ for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two different sodic soils (sodic soil I and sodic soil II and two BFGD rates. After the application of BFGD and leaching, the soil soluble salts were transformed from sodic salts containing Na2CO3 and NaHCO3 to neutral salts containing NaCl and Na2SO4. The sodium adsorption ratio (SAR, pH and electrical conductivity (EC decreased at all soil depths, and more significantly in the top soil depth. At a depth of 0-40 cm in both sodic soil I and sodic soil II, the SAR, EC and pH were less than 13, 4 dS m(-1 and 8.5, respectively. The changes in the chemical properties of the sodic soils reflected the changes in the ion composition of soluble salts. Leaching played a key role in the reclamation process and the reclamation effect was positively associated with the amount of leaching. The soil salts did not accumulate in the top soil layer, but there was a slight increase in the middle and bottom soil depths. The results demonstrate that the reclamation of sodic soils using BFGD is promising.

  20. Effect of byproducts of flue gas desulfurization on the soluble salts composition and chemical properties of sodic soils.

    Science.gov (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2013-01-01

    The byproducts of flue gas desulfurization (BFGD) are a useful external source of Ca(2+) for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two different sodic soils (sodic soil I and sodic soil II) and two BFGD rates. After the application of BFGD and leaching, the soil soluble salts were transformed from sodic salts containing Na2CO3 and NaHCO3 to neutral salts containing NaCl and Na2SO4. The sodium adsorption ratio (SAR), pH and electrical conductivity (EC) decreased at all soil depths, and more significantly in the top soil depth. At a depth of 0-40 cm in both sodic soil I and sodic soil II, the SAR, EC and pH were less than 13, 4 dS m(-1) and 8.5, respectively. The changes in the chemical properties of the sodic soils reflected the changes in the ion composition of soluble salts. Leaching played a key role in the reclamation process and the reclamation effect was positively associated with the amount of leaching. The soil salts did not accumulate in the top soil layer, but there was a slight increase in the middle and bottom soil depths. The results demonstrate that the reclamation of sodic soils using BFGD is promising. PMID:23936481

  1. Modeling the effects of saline groundwater and irrigation water on root zone salinity and sodicity dynamics in agro-ecosystems

    NARCIS (Netherlands)

    Shah, S.H.H.

    2013-01-01

    Recent trends and future projections suggest that the need to produce more food and fibre for the world’ s expanding population will lead to an increase in the use of marginal-quality water and land resources (Bouwer, 2000; Gupta and Abrol, 2000; Wild, 2003). This is particularly relevant to l

  2. Uncoupling of sodium and chloride to assist breeding for salinity tolerance in crops.

    Science.gov (United States)

    Genc, Yusuf; Oldach, Klaus; Taylor, Julian; Lyons, Graham H

    2016-04-01

    The separation of toxic effects of sodium (Na(+) ) and chloride (Cl(-) ) by the current methods of mixed salts and subsequent determination of their relevance to breeding has been problematic. We report a novel method (Na(+) humate) to study the ionic effects of Na(+) toxicity without interference from Cl(-) , and ionic and osmotic effects when combined with salinity (NaCl). Three cereal species (Hordeum vulgare, Triticum aestivum and Triticum turgidum ssp. durum with and without the Na(+) exclusion gene Nax2) differing in Na(+) exclusion were grown in a potting mix under sodicity (Na(+) humate) and salinity (NaCl), and water use, leaf nutrient profiles and yield were determined. Under sodicity, Na(+) -excluding bread wheat and durum wheat with the Nax2 gene had higher yield than Na(+) -accumulating barley and durum wheat without the Nax2 gene. However, under salinity, despite a 100-fold difference in leaf Na(+) , all species yielded similarly, indicating that osmotic stress negated the benefits of Na(+) exclusion. In conclusion, Na(+) exclusion can be an effective mechanism for sodicity tolerance, while osmoregulation and tissue tolerance to Na(+) and/or Cl(-) should be the main foci for further improvement of salinity tolerance in cereals. This represents a paradigm shift for breeding cereals with salinity tolerance. PMID:26607560

  3. 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

  4. 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)

  5. Calcareous Sodic Soil Reclamation as Affected by Corn Stalk Application and Incubation:A Laboratory Study

    Institute of Scientific and Technical Information of China (English)

    LI Fa-Hu; R.KEREN

    2009-01-01

    A laboratory lysimeter experiment was conducted to investigate the effects of forage corn (Zea mays L.) stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation.The experimental treatments tested were soil exchangeable sodium percentage (ESP) levels of 1,11,and 19,added corn stalk contents of 0 to 36 g kg-1,and incubation durations of 30 and 60 days.The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution,subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution,and finally significantly contributed to reduction on soil sodicity level.The reclamation efficiency of calcareous sodic soils increased with the added corn stalk.When corn stalks were added at the rates of 22 and 34 g kg-1 into the soil with initial ESP of 19,its ESP value was decreased by 56% and 78%,respectively,after incubation of 60 days and the leaching of 6.5 pore volumes (about 48 L of percolation water) with distilled water.Therefore,crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.

  6. 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.

  7. 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.

  8. 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...

  9. The petrogenesis of sodic island arc magmas at Savo volcano, Solomon Islands

    Science.gov (United States)

    Smith, D. J.; Petterson, M. G.; Saunders, A. D.; Millar, I. L.; Jenkin, G. R. T.; Toba, T.; Naden, J.; Cook, J. M.

    2009-12-01

    Savo, Solomon Islands, is a historically active volcano dominated by sodic, alkaline lavas, and pyroclastic rocks with up to 7.5 wt% Na2O, and high Sr, arc-like trace element chemistry. The suite is dominated by mugearites (plagioclase-clinopyroxene-magnetite ± amphibole ± olivine) and trachytes (plagioclase-amphibole-magnetite ± biotite). The presence of hydrous minerals (amphibole, biotite) indicates relatively wet magmas. In such melts, plagioclase is relatively unstable relative to iron oxides and ferromagnesian silicates; it is the latter minerals (particularly hornblende) that dominate cumulate nodules at Savo and drive the chemical differentiation of the suite, with a limited role for plagioclase. This is potentially occurring in a crustal “hot zone”, with major chemical differentiation occurring at depth. Batches of magma ascend periodically, where they are subject to decompression, water saturation and further cooling, resulting in closed-system crystallisation of plagioclase, and ultimately the production of sodic, crystal and feldspar-rich, high-Sr rocks. The sodic and hydrous nature of the parental magmas is interpreted to be the result of partial melting of metasomatised mantle, but radiogenic isotope data (Pb, Sr, Nd) cannot uniquely identify the source of the metasomatic agent.

  10. 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).

  11. Simplified vibratory characterization of alluvial basins

    CERN Document Server

    Semblat, Jean-François; Duval, Anne-Marie

    2011-01-01

    For the analysis of seismic wave amplification, modal methods are interesting tools to study the modal properties of geological structures. Modal approaches mainly lead to information on such parameters as fundamental frequencies and eigenmodes of alluvial basins. For a specific alluvial deposit in Nice (France), a simplified modal approach involving the Rayleigh method is considered. This approach assumes a set of admissible shape functions for the eigenmodes and allows a fast estimation of the fundamental frequency of the basin. The agreement between modal numerical results and experimental ones is satisfactory. The simplified modal method then appears as an efficient mean for the global vibratory characterization of geological structures towards resonance.

  12. 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

  13. 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...

  14. 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

  15. 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/...

  16. Soil alkalinization and irrigation in the sahelian zone of Niger : 2. Agronomic consequences of alkalinity and sodicity

    OpenAIRE

    Marlet, S.; Barbiéro, Laurent; Valles, V.

    1998-01-01

    Soils of the terraces of the Niger River have locally undergone, prior to irrigation, a process of alkalinization. The use of the resulting nonsaline sodic soils [pHs 8.5-9.8 (s is "on saturated paste"), ECs = 2.2-3.2 dS/m, SAR = 12-28 (mmol/L)(at the power 1/2), exchangeable sodium percentage (ESP) = 5-40] is greatly limited because of their alkalinity and sodicity. The mechanisms of degradation affecting the soil physicochemical properties, the water supply, and the mineral nutrition of cro...

  17. Calibration of a one-dimensional water flow model for the evaluation of the reclamation success of saline soil substrates

    Science.gov (United States)

    Shaygan, Mandana; Baumgartl, Thomas; Arnold, Sven; Reading, Lucy; Fletcher, Andrew

    2015-04-01

    Highly saline-sodic soils restrict plant establishment. Salt affected soils may be reclaimed by leaching salts from a potential root zone. Soil amendments can be used as a reclamation technique to improve the soil pore system and hydraulic functions, which allows the downward transport of water under certain precipitation conditions. The objective of this study was to investigate salt movement within saline-sodic soil at a small scale in soil columns and assess the success of amendment strategies for reclamation of the soil. For the purpose of predicting the effect of typical rainfall scenarios on the reclamation of saline-sodic soils, a one-dimensional numerical water flow model (HYDRUS-1D) was tested and calibrated. The model was calibrated using data from laboratory column experiments. A saline-sodic soil was packed into 30 cm long columns (diameter 7cm) from a depth of 10 to 30 cm and then covered with the same soil, however amended with 40% (wt/wt) fine sand and 20% (wt/wt) wood chips, respectively. A column filled with the saline-sodic soil only to a depth of 30 cm was used as a control. The experiments were carried out by establishing an initial pressure head of -60 cm at the soil surface. Based on climate data from a location in south-west Queensland, rainfall scenarios with 50% and 1% probability of annual exceedance for this location were calculated and applied to the soil columns. The hydrological response in the columns was monitored by measuring the water potential using tensiometers installed in three depths (3, 11 and 25 cm) and knowledge of inflow and outflow of the columns. The simulation captured the observed trends in the results for the investigated columns and measured depths under heavy rainfall events as well as surface substrates exposed to small rainfall events, where the simulated and measured results were in very good agreement, with R2 values generally ranging between 0.92 and 0.98. The simulated results also provided a good description

  18. 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

  19. THE EFFECT OF SALINITY-SODICITY AND GLYPHOSATE FORMULATIONS – AVANS PREMIUM 360 SL ON PHOSPHOMONOESTERASE ACTIVITIES IN SANDY LOAM

    Directory of Open Access Journals (Sweden)

    Maciej Płatkowski

    2016-01-01

    Full Text Available The aim of study was to determine the influence of NaCl and glyphosate-based herbicide Avans Premium 360 SL on acid and alkaline phosphomonoesterase activities in sandy loam. The experiment was carried out in laboratory conditions on sandy loam with Corg content 10.90 g/kg. Soil was divided into half kilogram samples and adjusted to 60% of maximum water holding capacity. In the experiment dependent variables were: I – dosages of Avans Premium 360 SL (0, a recommended field dosage – FD, a tenfold higher dosage – 10 FD and hundredfold higher dosage – 100 FD, II – amount of NaCl (0, 3% and 6%, III – day of experiment (1, 7, 14, 28 and 56. On days of experiment the activity of alkaline and acid phosphomonoesterase activity was assayed spectrophotometrically. The obtained result showed that the application of Avans Premium 360 SL decreased in acid and alkaline phosphomonoesterase activity in clay soil. Significant interaction effect between the dosage of Avans Premium 360 SL, NaCl amount and day of experiment was reported in the experiment. The inhibitory effect of Avans Premium 360 SL was the highest in soil with NaCl at the amount of 6%.

  20. Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

    OpenAIRE

    Salihu Lukman; Mohammed Hussain Essa; Nuhu Dalhat Mu'azu; Alaadin Bukhari

    2013-01-01

    In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples elec...

  1. Relict alluvial fans of northwestern part of Matarsko podolje

    Directory of Open Access Journals (Sweden)

    Uroš Stepišnik

    2007-12-01

    Full Text Available Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which appears between flysch and limestone. The most extensive contact of this type is in western Slovenia, in the area of Matarsko podolje, where a variety of typical contact karst depression features can be found. Relict alluvial fans on contact karst are the result of the gradual denudation of alluvial cover from flysch and chemical denudation of carbonate bedrock in the area of alluvial fans. Geomorphologic features and processes on alluvial fans, and the influences of alluvial fans on the development of local karst have been investigated in detail.

  2. Mapping soil salinity in irrigated land using optical remote sensing data

    Directory of Open Access Journals (Sweden)

    Rachid Lhissoui

    2014-04-01

    Full Text Available Soil salinity caused by natural or human-induced processes is certainly a severe environmental problem that already affects 400 million hectares and seriously threatens an equivalent surface. Salinization causes negative effects on the ground; it affects agricultural production, infrastructure, water resources and biodiversity. In semi-arid and arid areas, 21% of irrigated lands suffer from waterlogging, salinity and/or sodicity that reduce their yields. 77 million hectares are saline soils induced by human activity, including 58% in the irrigated areas. In the irrigated perimeter of Tadla plain (central Morocco, the increased use of saline groundwater and surface water, coupled with agricultural intensification leads to the deterioration of soil quality. Experimental methods for monitoring soil salinity by direct measurements in situ are very demanding of time and resources, and also very limited in terms of spatial coverage. Several studies have described the usefulness of remote sensing for mapping salinity by its synoptic coverage and the sensitivity of the electromagnetic signal to surface soil parameters. In this study, we used an image of the TM Landsat sensor and field measurements of electrical conductivity (EC, the correlation between the image data and field measurements allowed us to develop a semi-empirical model allowing the mapping of soil salinity in the irrigated perimeter of Tadla plain. The validation of this model by the ground truth provides a correlation coefficient r² = 0.90. Map obtained from this model allows the identification of different salinization classes in the study area.

  3. Controls on alluvial fan long-profiles

    Science.gov (United States)

    Stock, J.D.; Schmidt, K.M.; Miller, D.M.

    2008-01-01

    Water and debris flows exiting confined valleys have a tendency to deposit sediment on steep fans. On alluvial fans where water transport of gravel predominates, channel slopes tend to decrease downfan from ???0.10-0.04 to ???0.01 across wide ranges of climate and tectonism. Some have argued that this pattern reflects grain-size fining downfan such that higher threshold slopes are required just to entrain coarser particles in the waters of the upper fan, whereas lower slopes are required to entrain finer grains downfan (threshold hypothesis). An older hypothesis is that slope is adjusted to transport the supplied sediment load, which decreases downfan as deposition occurs (transport hypothesis). We have begun to test these hypotheses for alluvial fan long-profiles using detailed hydraulic and particle-size data in sediment transport models. On four alluvial fans in the western U.S., we find that channel hydraulic radiiare largely 0.5-0.9 m at fan heads, decreasing to 0.1-0.2 m at distal margins. We find that median gravel diameter does not change systematically along the upper 60%-80% of active fan channels as slope declines, so downstream gravel fining cannot explain most of the observed channel slope reduction. However, as slope declines, channel-bed sand cover increases systematically downfan from areal fractions of America.

  4. Allelopathy in saline agricultural land: Vegetation successional changes and patch dynamics.

    Science.gov (United States)

    Mahmood, K; Malik, K A; Sheikh, K H; Lodhi, M A

    1989-02-01

    In reclamation fields of salt-affected wasteland, five plant communities colonized the undisturbed land, represented byCynodon dactylon, Desmostachya bipinnata, Prosopis juliflora, Sporobolus arabicus, andSuaeda fruticosa. Kallar grass (Leptochloa fusca), a highly salt tolerant plant when cultivated, shared dominance withCynodon, Desmostachya, andSporobolus in 15-month-old fields, whereasPolypogon was the only dominant species in 30-month-old kallar grass fields. Through successional stages, soil pH, salinity, sodicity, and Na, K, Ca + Mg significantly decreased due to leaching. Electrical conductivity successively changed from 13.0 to 3.0 to 1.0, while soil total nitrogen, NH4 nitrogen, NO3 nitrogen and available P significantly increased. In high-density kallar grass fields, six weed species appeared only in well-defined patches and radially eliminated or reduced kallar grass growth. Many soil factors, such as pH, EC, NH4 nitrogen, NO3 nitrogen and available P analyzed in patch vegetation soils, were mostly either comparable or significantly better than those of surrounding kallar grass fields. On the other hand, aqueous extracts of all six invading species and kallar grass significantly reduced kallar grass seed germination to varying degrees. Further, decaying leaf powder of allelopathically suspected species significantly reduced kallar grass biomass, which varied from species to species and in most cases corresponded with field data of kallar grass in patch vegetation. It should be strongly pointed out that allelopathic behavior discussed in patch dynamics was in areas where soil saline-sodic conditions had improved greatly (e.g., EC = from 13.0 to only 1.0) due to kallar grass plantation. Further,Suaeda appeared to be a poor competitor when soil conditions improved for other species as well, and it could not capitalize on its evolutionary strategic trait of performing well in saline-sodic conditions. To our knowledge, this is the first report indicating that

  5. Removal of Cadmium(II and Lead(II ions from aqueous phase on sodic bentonite

    Directory of Open Access Journals (Sweden)

    Luz Stella Gaona Galindo

    2013-04-01

    Full Text Available This paper describes the adsorption of Cd2+and Pb2+ions using sodic bentonite clay type Fluidgel modified. The Fluidgelbefore and after chemical modification and thermal activation was characterized by different techniques including X-ray diffraction, thermal analysis, Fourier transform infrared, surface area, helium pycnometry, cation exchange capacity and scanning electron microscopy. Pseudo-first order, pseudo-second order and intra-particle diffusion models were used to analyze the kinetic curves. Equilibrium data were analyzed using Langmuir and Freundlich models. The thermodynamic study indicated that lead adsorption process is endothermic and interactions between clays and solutions of lead occurred spontaneously, while cadmium adsorption revealed an exothermic and spontaneous nature. The maximum removal efficiencies were 97.62% for Cd(II using Fluidgelmodified chemically and 91.08% for lead by Fluidgel modified chemical and thermally.

  6. Silicon-mediated changes on some physiological and enzymatic parameters symptomatic of oxidative stress in barley grown in sodic-B toxic soil.

    Science.gov (United States)

    Gunes, Aydin; Inal, Ali; Bagci, Esra G; Coban, Sencan

    2007-06-01

    The effect of silicon (Si) on the growth, sodium (Na), chloride (Cl), boron (B) concentrations, lipid peroxidation (MDA), membrane permeability (MP), lypoxygenase activity (LOX), proline (PRO) and H(2)O(2) accumulation, and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of barley grown in original sodic-B toxic soil were investigated. Si applied to the sodic-B toxic soil at 70, 140 and 280 mg kg(-1) levels significantly increased Si concentrations of the plants and counteracted the deleterious effects of sodicity (Na ions) and B on shoot growth. Membrane permeability and the concentrations of H(2)O(2) and MDA increased, while PRO concentration decreased in plants grown in sodic-B toxic soil without Si. LOX activity was increased by applied Si. Compared with control plants, the activities of SOD and CAT were decreased, but APX was increased by applied Si levels. PMID:17070965

  7. Water logging and salinity control for environmentally sustainable crop production

    International Nuclear Information System (INIS)

    Irrigation supplies at proper time and adequate quantities are imperative for potential agricultural production under arid and semi-arid climatic conditions. To achieve this goal one of the largest integrated irrigation network was established. Without adequate drainage it resulted in the problems of water logging and salinity. To control these problems a big programme of Salinity Control and Reclamation projects (SCARPs) was initiated during 1960 and 82 such SCARPs have been completed and 9 were in progress up to June, 2002 covering an area of 18.6 ma (7.5 mh) at a cost of Rs.93 billions. Under these projects 12746 tube wells in fresh, 3572 in saline groundwater and 13726 km surface and 12612 km tile pipes covering 6391.7 ha, 160 km interceptor drains have been constructed an area of 0.998 ma (GCA). In addition to this some other measures like on farm water management, canal command project, canal lining, construction of evaporation ponds, establishment of research Inst./Organizations were also taken. Many drainage plans like Master Plan (1963), Northern Regional Plan (1967), Water Sector Investment Plan Study (1990), Right Bank Master Plan (1992), Drainage Sector Environmental Assessment (1993) and National Drainage Programme (1995) were prepared and implemented. The cost of the, phase-I of the National Drainage Programme was 785 million US$. The main activities undertaken were remodeling/extension of existing surface and new drains; rehabilitation/replacement of saline ground water (SGW) tube wells; construction of interceptor drains, reclamation of waterlogged areas through biological drainage and transfer of fresh ground water tube wells to the farmers. The data indicate that all the measures taken have played a significant role in reducing the water logging, salinity/sodicity and have increased the crop production and consequently improved the socio-economic conditions of the peoples especially the farming community. The environment in these areas was also

  8. Reconciling Holocene Alluvial Records in Buckskin Wash, Southern Utah

    OpenAIRE

    Harvey, Jonathan E.

    2009-01-01

    Most approaches to interpreting alluvial records in drylands fall into one of two categories: (1) The "arroyo problem," wherein workers study cycles of streambed aggradation and degradation in broad, unconstricted alluvial valleys; and (2) paleoflood hydrology, where alluvial sequences in constricted bedrock canyons are interpreted as paleoflood deposits from streams with stable channel grade and geometry. Both approaches can be valid in their end-member settings, but there is confusion abo...

  9. 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.

  10. A dynamical study on sodium accumulation and soil reclamation in secondary salinization

    Science.gov (United States)

    Mau, Y.; Porporato, A. M.

    2014-12-01

    Irrigation with saline water, together with poor leaching of the salts in the root zone, are the major causes of human-caused soil salinization, or secondary salinization. About 20% of irrigated land are salt-affected, and nearly four million acres of farmland are estimated to be lost to excessive salt every year. The development of a high percentage of sodium in the soil exchangeable complex is especially problematic, changing the soil structure and greatly reducing its hydraulic conductivity. This condition, called sodicity, mainly affects arid and semi-arid areas, where precipitation is not adequate to leach salts. We investigate the coupled water and salt balance equations in the root zone irrigated with saline water. By describing the fractions of sodium (Na) and calcium (Ca) cations in the irrigation water, soil water, and exchangeable complex, we determine the dynamics of the total salt concentration in the soil water (C) and of the Exchangeable Sodium Percentage (ESP). We found that the dynamics of the ESP can be one order of magnitude slower than that of C: while the typical time scale of convergence of C to its steady-state value is of the order of 1 year, the ESP evolves in a typical time scale of 1 decade and more. These results provide useful indications for the reclamation of sodic soils, which can be accelerated through the replacement of Na cations by Ca ions in the exchangeable complex, often by means of the application of gypsum to the irrigation water. We show that a two-phase managing scheme can shorten the time scale of reclamation, when compared to irrigation with same volumes of water of better quality (low C levels): first irrigation water with high salt concentration and low fraction of Na brings the ESP to low levels in relatively short time scales; then good quality irrigation water (low C) can be applied, decreasing total salinity levels. We also explored the effects of high sodicity on the soil hydraulic conductivity by adding a

  11. Hypertonic saline.

    Science.gov (United States)

    Constable, P D

    1999-11-01

    A key feature in the successful resuscitation of dehydrated or endotoxemic ruminants is the total amount of sodium administered. Administration of small volumes of HS and HSD offer major advantages over large volumes of isotonic saline because HS and HSD do not require intravenous catheterization or periodic monitoring, and are therefore suitable for use in the field. Hypertonic saline and HSD exert their beneficial effect by rapidly increasing preload and transiently decreasing afterload. Contrary to early reports, HS and HSD decrease cardiac contractility and do not activate a pulmonary reflex. The osmolality of HS and HSD should be 2400 mOsm/L (7.2% NaCl solution, 8 times normal plasma osmolality). Use of HS and HSD solutions of different osmolality to 2400 mOsm/L should be avoided at all costs, as too low a tonicity removes the main advantages of HS (low cost, decreased infusion time), whereas too high a tonicity may cause rapid vasodilation and decreased cardiac contractility, resulting in death. Rapid administration (> 1 mL/kg-1/min-1) of HS (2400 mOsm/L) should be avoided, as the induced hypotension may be fatal when coupled with a transient decrease in cardiac contractility. For treating dehydrated adult ruminants, HS (2400 mOsm/L, 4-5 mL/kg i.v. over 4-5 minutes) should be administered through the jugular vein and the cow allowed to drink water. This means that 2 L of HS should be administered to adult cattle. HSD should be administered in conjunction with isotonic oral electrolyte solutions to all calves 8% or more dehydrated (eyes recessed > or = 4 mm into the orbit, cervical skin tent duration > 6 seconds) or calves with reduced cardiac output (fetlock temperature isotonic oral electrolyte solution. This means that 120-200 mL of HSD of HSD should be administered to a calf. HSD should be routinely administered to severely depressed or comatose calves, as HSD provides the fastest method of resuscitation while rapidly reversing the effects of hyperkalemia

  12. Saline Sinus Rinse Recipe

    Science.gov (United States)

    ... Allergy Library ▸ Saline Sinus Rinse Recipe Share | Saline Sinus Rinse Recipe Saline sinus rinses can bring relief to patients with chronic sinus or rhinitis problems without the use of medication. ...

  13. Sodic metasomatism in a dacite weathering profile in Pinxiang, Guangxi, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Pinxiang weathering profile is well developed on Early Triassic dacite lavas of the Baisi Formation. At the top of the profile is developed a red clay zone which is characterized mineralogically by kaolinite, iron oxide minerals, quartz, and a small amount of illite, montmorillonite and vermiculite. In going downwards the red clay zone gives way to a saprolite zone in which plagioclase pseudomorphs have been well preserved although replaced by kaolinite. Beneath the saprolite zone is the saprock zone characterized by less weathering for dacite. At the bottom of the weathering profile is the parent material, dacite, which is composed mainly of plagioclase, quartz, K-feldspar and biotite which have been largely altered into chlorite owing to submarine extrusion of dacite lavas. Some layers in the weathering profile show obvious sodium enrichment and potassium depletion relative to others. In the Al2O3-(CaO*+Na2O)-K2O triangular diagram, the weathering trends of these layers in the middle stage are remarkably deviated from normal ones. Both mineralogy and micro-morphology of these layers indicate such deviation resulted from sodic metasomatism of orthoclase.

  14. COMPARISON OF THE PHYSICAL AND CHEMICAL PROPERTIES OF THE DISPERSIVE AND SODIC SOILS

    Directory of Open Access Journals (Sweden)

    G. NAGY

    2016-03-01

    Full Text Available Some cohesive soils show very little resistance when it comes to interaction with relatively pure water, however the water flow itself does not have to necessarily cause any damage in the soil structure. These soils are so poorly bonded, that this small amount of water flow can lead to structural breakdown. The effect caused several dike and earth dam damages and failures in the past years, therefore the behavior itself is considered as a geotechnical risk in the process of design. The dike breaches lead to the emergence of knowing how to identify and locate the areas and soil types, where the hazardous soils occur. In geotechnical engineering these soils are referred as dispersive soils, and their properties are known since the 1960s. In the recent years researches were carried out to get a better point of view of the reasons of these kind of behavior. Therefore the investigation of physical and chemical properties were made. The results showed that the dispersive behavior can be connected with the amount of dissolved salts in the soil extract. Since these are known as the origin of sodic soils, the relationship was investigated.

  15. Calc-sodic zoning in rocks from Lagoa Real uranium Province, state of Bahia, Brazil

    International Nuclear Information System (INIS)

    Preliminary studies of the lithogeochemistry, carried out on various deposits from the Uranium Province of Lagoa Real, show that in relation to the complex and multiphased processes of metasomatism, the sodic metasomatites are younger and were superposed on the potassic metasomatites. Such metasomatites developed in zones of extended and rejuvenated faults, after the transformation of the gnaisses, granitic rocks, amphibolites and ferruginous quartzites into various tectonites (mylonites, blastomylonites and protomylonites). The calcic metasomatism, subsequent to those phases, took place during the course of tectonothermal reactivations marking the termination of the principal metasomatic processes which aftected the rocks of Lagoa Real. The uranium deposit 'Jazida Laranjeiras', centrally situated in the Uranium Province of Lagoa Real is the only deposit in which the uranium mineralization is not intimately associated with the calcic metasomatism. Here, the ratio Na2O/CaO in the albitites is in the vicinity of 7,5 whereas in the other deposits this ratio decreases to values of about 1,5. The authors suggest calcic zoning (in the post-albitite phase) along the sigmoidal structure which localizes the uranium deposits, with an increase of the CaO content in the extreme parts of the structure - deposit 'Jazida Cachoeira' in the north and anomaly No. 02/12 in the south. Also suggested is the vertical zoning of calcium, whereby the intensity of the metasomatic phenomenon is increased towards the hanging wall side of the mieral parcel. (Author)

  16. Particle dynamics: The continuum of bedrock to alluvial river segments

    Science.gov (United States)

    Wohl, Ellen

    2015-07-01

    Particle dynamics refers to production, erosion, transport, and storage of particulate material including mineral sediment and organic matter. Particle dynamics differ significantly between the end members of bedrock and alluvial river segments and between alluvial river segments with different grain-size distributions. Bedrock segments are supply limited and resistant to change, with relatively slow, linear adjustments and predominantly erosion and transport. Particle dynamics in alluvial segments, in contrast, are transport limited and dominated by storage of mineral sediment and production of organic matter. Alluvial segments are resilient to change, with relatively rapid, multidirectional adjustments and stronger internal influences because of feedbacks between particles and biota. Bedrock segments are the governors of erosion within a river network, whereas alluvial segments are the biogeochemical reactors. Fundamental research questions for both types of river segments center on particle dynamics, which limit network-scale incision in response to base level fall (bedrock segments) and habitat, biogeochemical reactions, and biomass production (alluvial segments). These characterizations illuminate how the spatial arrangement of bedrock and alluvial segments within a river network influence network-scale resistance and resilience to external changes in relative base level, climate, and human activities.

  17. Effect of saline soil parameters on endo mycorrhizal colonisation of dominant halophytes in four Hungarian sites

    Energy Technology Data Exchange (ETDEWEB)

    Fuzy, A.; Biro, B.; Toth, T.

    2010-07-01

    Soil and root samples were collected from the rhizosphere of dominant halophytes (Artemisia santonicum, Aster tripolium, Festuca pseudovina, Lepidium crassifolium, Plantago maritima and Puccinellia limosa) at four locations with saline soils in Hungary. The correlations- between arbuscular mycorrhiza (AM) fungal colonisation parameters (% colonisation, % arbuscules) and soil physical, chemical and biological parameters were determined Endomycorrhiza colonisation was found to be negatively correlated with the electric conductivity of the soil paste, the salt-specific ion concentrations and the cation exchange capacity, showing the sensitivity of AM fungi at increasing salt concentrations, independently of the types of salt-specific anions. A positive correlation was detected between the mycorrhiza colonisation and the abundance of oligotroph bacteria known to be the less variable and more stable (k-strategist) group. This fact and the negative correlation found with the humus content underlines the importance of nutrient availability and the limitations of the symbiotic interactions in stressed saline or sodic soils. (Author) 29 refs.

  18. Paragenesis of sodic pyroxene-bearing quartz schists: implications for the P-T history of the Sanbagawa belt

    Science.gov (United States)

    Enami, Masaki; Wallis, Simon R.; Banno, Yasuyuki

    1994-03-01

    Sodic pyroxene (jadeite content X jd=0.1 0.3) occurs locally as small inclusions within, albite porphyroblasts and in the matrix of hematite-bearing quartz schists in the Sanbagawa (Sambagawa) metamorphic belt, central Shikoku, Japan. The sodic, pyroxene-bearing samples are characteristically free from chlorite and their typical mineral assemblage is sodic pyroxene+subcalcic (or sodic) amphibole+phengitic mica+albite+quartz+hematite+titanite±epidote. Spessartine-rich garnet occurs in Mn-rich samples. Sodic pyroxene in epidote-bearing samples tends to be poorer in acmite content (average X Acm=0.26 0.50) than that in the epidote-free samples ( X Acm=0.45 0.47). X Jd shows no systematic relationship to metamorphic grade, and is different among the three sampling regions [Saruta-gawa, Asemi-gawa and Bessi (Besshi)]. The average X Jd of the Saruta-gawa samples (0.21 0.29) is higher than that of the Asemi-gawa (0.13 0.17) and Bessi (0.14 0.23). The P-T conditions of the Asemi-gawa and Bessi regions are estimated at 5.5 6.5 kbar, >360°C in the chlorite zone, 7 8.5 kbar, 440±15°C in the garnet zone and 8 9.5 kbar, 520±25°C in the albite-biotite zone. Metamorphic pressure of the Saruta-gawa region is systematically 1 1.5 kbar higher than that of the Asemi-gawa and Bessi regions, and materials of the Saruta-gawa region have been subducted to a level 3 5 km deeper than materials that underwent metamorphism at equivalent temperatures and are now exposed in the Asemi-gawa and Bessi regions. Pressure slightly increases toward the north (structurally high levels) through the Sanbagawa belt of central shikoku. Two types of zonal structure were observed in relatively coarse-grained sodic pyroxenes in the matrix. One type is characterized by increasing X Jd from core to rim, the other type by decreasing X Jd from core to rim. Both types of zoned pyroxenes show an increase in X Fe 2+[=Fe2+/(Fe2++Mg)] from core to rim. The first type of zoning was observed in a sample from the

  19. Calculation of stability of sodic phases in high-pressure metapelites and observation of Sambagawa metamorphic rocks

    Science.gov (United States)

    Kouketsu, Y.; Enami, M.

    2010-12-01

    P-T pseudosection analyses of high-pressure metapelites from several subduction related regions were carried out by using the computer program Perple_X 07 in order to determine the mineral equilibrium, particularly the stability of sodic phases, in the model system MnO-Na2O-K2O-CaO-FeO-MgO-Al2O3-SiO2-H2O. Metapelites from Sambagawa, Western Alps, New Caledonia, Greece, and South Tianshan were selected for these analyses. Although the occurrence of sodic pyroxene in these metapelite samples is free or very rare, all the samples are considered to have undergone high-pressure metamorphism under blueschist-eclogite facies conditions. The bulk rock compositions of these metapelites have relatively low XNa [=Na/(Al + Na)] values. Therefore, the rare occurrences of sodic pyroxene in these samples are possibly due to their characteristic bulk rock compositions, although this has not been proved yet. The calculation results for the stability of sodic phases under the blueschist and eclogite facies conditions indicate the following. (1) Sodic pyroxene in the studied metapelites is stable only under higher-pressure conditions of P > 2.5 GPa, although its stable P-T range increases toward the lower-pressure side with increasing XNa value of the bulk-rock composition. (2) Paragonite and glaucophane are stable throughout the wide XNa range of bulk-rock compositions of host rocks under the blueschist and quartz-eclogite facies conditions. (3) The stability field of paragonite enlarges with the presence of CO2 in the metamorphic fluid. Thus, the high stability of paragonite and glaucophane in metapelites and the close relationship between the stability of sodic pyroxene and the bulk-rock composition explain why omphacite-bearing metapelites are rarely found. Observations of Sambagawa metapelites were carried out on the basis of these results. In the Besshi region of the Sambagawa belt, quartz grains with a high residual pressure of up to 0.8 GPa extensively occur as inclusions in

  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. 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,...

  2. Amylase produced by Bacillus sp. SI-136 isolated from sodic-alkaline soil for efficient starch desizing

    OpenAIRE

    Sarethy, Indira P; Yashi Saxena; Aditi Kapoor; Manisha Sharma; Rohan Seth; Harsh Sharma; Sharma, Sanjeev K; Sanjay Gupta

    2012-01-01

    Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group based on 16S rDNA sequence. It produced α-amylase of 26 kDa with maximum activity at pH 10.0, stable up to pH 12.0 and 80oC. Mn2+ enhanced its activity as also 10% NaCl in medium. Agricultural waste substrates supported growth and enzyme activity was enhanced by 30% with sugarcane bagasse. The partially purified enzyme showed efficient desizing of cotton fabric at 50oC (40-60 min) or 70oC (...

  3. 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 ...

  4. 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...

  5. Contribution of alluvial groundwater to the outflow of mountainous catchments

    Science.gov (United States)

    Käser, Daniel; Hunkeler, Daniel

    2016-02-01

    Alluvial aquifers in mountainous regions cover typically a limited area. Their contribution to catchment storage and outflow is rarely isolated; alluvial groundwater discharge under gauging stations is generally assumed negligible; and hydrological models tend to lump alluvial storage with other units. The role of alluvial aquifers remains therefore unclear: can they contribute significantly to outflow when they cover a few percent of catchment area? Should they be considered a dynamic storage unit or merely a transmission zone? We address these issues based on the continuous monitoring of groundwater discharge, river discharge (one year), and aquifer storage (6 months) in the 6 km2 alluvial system of a 194 km2 catchment. River and groundwater outflow were measured jointly through "coupled gauging stations." The contribution of alluvial groundwater to outflow was highest at the outlet of a subcatchment (52 km2), where subsurface discharge amounted to 15% of mean annual outflow, and 85% of outflow during the last week of a drought. In this period, alluvial-aquifer depletion supported 75% of the subcatchment outflow and 35% of catchment outflow—thus 3% of the entire catchment supported a third of the outflow. Storage fluctuations occurred predominantly in the aquifer's upstream part, where heads varied over 6 m. Not only does this section act as a significant water source, but storage recovers also rapidly at the onset of precipitation. Storage dynamics were best conceptualized along the valley axis, rather than across the more conventional riparian-channel transect. Overall the contribution of alluvial aquifers to catchment outflow deserves more attention.

  6. 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

  7. 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.

  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. Restoration of sodic soils involving chemical and biological amendments and phytoremediation by Eucalyptus camaldulensis in a semiarid region.

    Science.gov (United States)

    Seenivasan, R; Prasath, V; Mohanraj, R

    2015-06-01

    Salt-affected soils in semiarid regions impede the agricultural productivity and degrade the ecosystem health. In South India, several hectares of land are salt-affected, where the evapotranspiration exceeds the annual precipitation. This study is an attempt to ameliorate sodic soils, by an experiment involving chemical treatment (addition of gypsum), organic amendments (decomposed bagasse pith and green manuring with Sesbania rostrata) and phytoremediation by plantation of Eucalyptus camaldulensis. The prime focus is to minimize the use of gypsum and improve the soil health in terms of nutrients, microbial population and enzyme activity in addition to sodicity reclamation. At the end of the third year, a reduction of 10 % in soil pH, 33 % in electrical conductivity and 20 % in exchangeable sodium percentage was achieved compared to the initial values. Three- to fourfold increases in organic carbon content were observed. Significant improvement in the available major and micronutrients of soil, microbial growth and enzyme activity was observed, suggesting phytoremediation by E. camaldulensis as a sustainable option for restoration of similar kind of degraded lands. PMID:25547478

  10. Impact of long and short term irrigation of a sodic soil with distillery effluent in combination with bioamendments.

    Science.gov (United States)

    Kaushik, A; Nisha, R; Jagjeeta, K; Kaushik, C P

    2005-11-01

    The study reports the effects of irrigation of a sodic soil with post methanation effluent (PME) of a distillery. Impact of long term effluent irrigation in the field (10 years) and short term effluent irrigation using different doses of PME in the laboratory (30 days) was studied in combination with three bioamendments i.e. farmyard manure, brassica residues and rice husk. Impact on various soil properties like EC, pH, total organic carbon (TOC), total Kjeldahl nitrogen (TKN), available phosphorus, exchangeable K, Na, Ca, Cl, microbial population and soil enzyme activities were studied. Long term application of PME proved useful in significantly increasing TOC, TKN, K, P and soil enzymatic activities in the soil but tended to build up harmful concentration of Na, that could be chelated by bioamendments. In short terms studies, application of 50% PME along with bioamendments proved to be the most useful in improving the properties of sodic soil and also favoured successful germination and improved seedling growth of pearl millet. PMID:15939590

  11. Amylase produced by Bacillus sp. SI-136 isolated from sodic-alkaline soil for efficient starch desizing

    Directory of Open Access Journals (Sweden)

    Indira P. Sarethy

    2012-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Bacillus sp. SI-136, isolated from sodic-alkaline soil, showed 94% similarity to B. cereus group based on 16S rDNA sequence. It produced α-amylase of 26 kDa with maximum activity at pH 10.0, stable up to pH 12.0 and 80oC. Mn2+ enhanced its activity as also 10% NaCl in medium. Agricultural waste substrates supported growth and enzyme activity was enhanced by 30% with sugarcane bagasse. The partially purified enzyme showed efficient desizing of cotton fabric at 50oC (40-60 min or 70oC (60 min with Tegewa rating 7-8, and at 95oC (20 min with Tegewa rating 9, properties enabling utility in textile industries.

  12. 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...

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

    International Nuclear Information System (INIS)

    An isotopic hydrology section across the North China Plain has been studied to investigate problems of groundwater age, flow system and saline water origin in a semi-arid pre-mountain artesian basin. Two local and one regional flow system along the section have been recognized. Turnover time of water for alluvial fan, shallow and regional systems are estimated to be the order of 102, 103, and 104 years respectively. Specific flow rates for the three systems have been calculated. Only less than 5 percent of flow from alluvial fan is drained by the regional flow system and the rest, in natural conditions, discharges at surface in the front edge of an alluvial fan and forms a groundwater discharge belt at a good distance away from the mountain foot. Developed in the alluvial plain and coastal plain areas the shallow flow system embraces a series of small local systems. Groundwater in these systems appears to be the salt carrier during continental salinization. It washes salt out of the recharge area and deep-occurred strata by circulating and carries it up to the surface in lowland areas. Consequently, in parallel with salinization at surface a desalinization process occurs at depth, which provides an additional explanation for the existing thick deep fresh water zone in most arid and semi-arid regions, where continental salting process is in progress. (author). 6 refs, 8 figs, 4 tabs

  14. 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.

  15. Salinity Management in Agriculture

    Science.gov (United States)

    Existing guidelines and standards for reclamation of saline soils and management to control salinity exist but have not been updated for over 25 years. In the past few years a looming water scarcity has resulted in questioning of the long term future of irrigation projects in arid and semi arid regi...

  16. Influence of upwelling saline groundwater on iron and manganese cycling in the Rio Grande floodplain aquifer

    International Nuclear Information System (INIS)

    Salinity contributions from upwelling groundwater significantly degrade water quality in the Rio Grande, a major source of water for the southwestern USA. This study considers the influence of this upwelling water on the geochemistry and microbiology of the Rio Grande floodplain alluvial aquifer. The composition of surface water, groundwater, and floodplain sediment samples collected from three transects in the Socorro Basin was examined. Terminal-restriction fragment length polymorphism (T-RFLP) was also used to examine microbial biomass samples. The distribution of salinity in the floodplain groundwater largely reflects the configuration of local groundwater flow and mixing of two major water sources, deeply-sourced saline groundwater and river water. Microbial populations in the shallow aquifer consume O2 and NO3- and serve to redistribute metal oxides from the saturated zone to locations of groundwater discharge at the surface and possibly near the water table. The upwelling saline groundwater affects floodplain microbial processes by transporting reduced metals and organic electron donors to the alluvial aquifer system. This enhances metal reduction in the saturated zone and ultimately metal oxidation at or near the surface. Geochemical modeling suggests that mixing of the saline groundwater with more dilute water in the floodplain creates conditions more favorable for metal oxidation to occur and thereby influences the distribution of metal oxides

  17. 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

  18. Reuse of drainage water for rice and wheat growth during reclamation of saline-sodic soils in Pakistan under the national drainage program (NDP)

    OpenAIRE

    GHAFOOR, A.; Boers, T.M.

    2003-01-01

    Pakistan is facing scarcity of canal water for irrigated agriculture on 16 mha land. This problem is caused, among others, by the loss of surface storage capacity and by the current prolonged dry spell lasting over the several past years. Siltation of Mangla, Tarbela and Chashma Dams have caused a loss of . 5 km3 which is 25 % of the design capacity. Since this problem is increasing, there may be a gradual decrease of food production for a population of 140 million, which is expected to have ...

  19. Petrogenesis of coeval sodic and potassic alkaline magmas at Spanish Peaks, Colorado: Magmatism related to the opening of the Rio Grande rift

    Science.gov (United States)

    Lord, A. Brooke Hamil; McGregor, Heath; Roden, Michael F.; Salters, Vincent J. M.; Sarafian, Adam; Leahy, Rory

    2016-07-01

    Approximately coeval, relatively primitive (∼5-10% MgO with exception of a trachyandesite) alkaline mafic dikes and sills at or near Spanish Peaks, CO are divided into relatively sodic and potassic varieties on the basis of K2O/Na2O. Many of these dikes are true lamprophyres. In spite of variable alkali element ratios, the alkaline rocks share a number of geochemical similarities: high LIL element contents, high Ba and similar Sr, Nd and Hf isotope ratios near that of Bulk Earth. One important difference is that the potassic rocks are characterized by lower Al2O3 contents, typically less than 12 wt.%, than the sodic dikes/sills which typically have more than 13 wt.% Al2O3, and this difference is independent of MgO content. We attribute the distinct Al2O3 contents to varying pressure during melting: a mica-bearing, Al-poor vein assemblage for the potassic magmas melted at higher pressure than an aluminous amphibole-bearing vein assemblage for the sodic magmas. Remarkable isotopic and trace element similarities with approximately contemporaneous, nearby Rio Grande rift-related basalts in the San Luis Valley, indicate that the magmatism at Spanish Peaks was rift-related, and that lithosphere sources were shared between some rift magmas and those at Spanish Peaks. High Zn/Fe ratios in the Spanish Peaks mafic rocks point to a clinopyroxene- and garnet-rich source such as lithosphere veined by pyroxenite or eclogite. Lithospheric melting was possibly triggered by foundering of cool, dense lithosphere beneath the Rio Grande rift during the initiation of rifting with the potassic parent magmas generated by higher pressure melting of the foundered lithosphere than the sodic parent magmas. This process, caused by gravitational instability of the lithosphere (Elkins-Tanton, 2007) may be common beneath active continental rifts.

  20. Effects of Climate-Induced Hydrologic Modifications on Biogeochemical Cycling of Trace Metals in Alluvial and Coastal Watersheds

    Science.gov (United States)

    Lee, M.; Natter, M. G.; Keevan, J. P.; Guerra, K.; Saunders, J.; Uddin, A.; Humayun, M.; Wang, Y.; Keimowitz, A. R.

    2013-12-01

    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. This study employs field data and numerical modeling techniques to test assumptions about the effects of climate change on natural arsenic contamination of groundwater in alluvial aquifers and mercury bioaccumulation in coastal saltmarshes. The results show that the rises of sea level and river base during the warm Holocene period has led to an overall increase in groundwater arsenic concentration due to the development of reducing geochemical conditions and sluggish groundwater movement. Modeling results indicate that the intrusion of seawater occurring during high sea-level stand may lead to desorption of arsenic from the surfaces of hydrous oxides due to pH effects and ionic competition for mineral sorbing sites. Our results also show that contamination and bioaccumulation of Hg and other metals in estuarine and coastal ecosystems may be influenced by climate-induced hydrologic modifications (atmospheric deposition, riverine input, salinity level, etc.). An integrated research framework consisting of numerical modeling, long-term monitoring, laboratory experiments will be necessary for building a comprehensive understanding of the complex response of biogeochemical cycling of trace metals to climate change.

  1. 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.

  2. Experimental restoration and subsequent degradation of an alluvial meadow

    Czech Academy of Sciences Publication Activity Database

    Prach, Karel

    Praha : Agentura ochrany přírody a krajiny České republiky, 2012 - (Jongepierová, I.; Pešout, P.; Jongepier, J.; Prach, K.), s. 39-41 ISBN 978-80-87457-32-0 R&D Projects : GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : restoration * alluvial meadows * species diversity Subject RIV: EH - Ecology, Behaviour

  3. Land use change and its driving forces in alluvial-plain oasis

    Science.gov (United States)

    Xiao, Luxiang; Zhang, Zengxiang; Chen, Xi; Luo, Geping; Wen, Qingke

    2007-11-01

    Land use change and its driving factors are hot topics of global change research, and also important topics of sustainable development. This paper selected a small area in alluvial plain oasis in Xinjiang Autonomous region of China as the study area. Using Landsat TM data of 1987, 1998 and 2004, the dynamic process of the spatial-temporal characteristics of land use changes were analyzed to improve understanding and to find the driving forces of land use changes so that sustainable land utilization could be practiced. During the 17 years salt-alkali tolerant cropland, cereal cropland, vegetable-fruit land, and shrubbery, had decreased remarkably by 78.59%, 85.95%, 92.13%, 68.43%, respectively. Cotton-liquorice land, grape-hop land, planted forest, residential area in town, residential area in village, and saline-alkaline field had increased dramatically. The increased percentage received the value of 2432.11%, 10103.18%, 889.91%, 222.45%, 96.00%, 44.18%, respectively. By the logistic regression, the main driving factors were derived for each land use type. The advance of technology (fertilizer input, irrigation quota, and animal labor et al.) and market (unit are yield net) were the main driving factors. Policy, in a higher level, influenced the land use dynamics for all the land use changes.

  4. Determination of the stability of the uranyl ion sipped in τ-hydrogen phosphate of zirconium in sodic form

    International Nuclear Information System (INIS)

    The stability of the uranyl sipped in the zirconium τ-hydrogen phosphate in sodic form (τ-NaZrP), was carried out characterizing the complexes formed by Laser spectroscopy in the visible region and by X-ray photoelectron spectroscopy. The material was prepared by a new synthesis technique working in nitrogen atmosphere and to low temperatures. The sorption of the uranyl ion was made in acid media with concentrations of 10-4 and 10-5 of uranyl nitrate and with ion forces of 0.1 and 0.5 M of NaClO4. The spectra of induced fluorescence with laser (TRLFS) show that the uranyl is fixed in very acid media in three well differentiated species, to pH less acid, the specie of long half life disappears and are only those of short half life. The results of the binding energy obtained by XPS indicate that the binding energy of the uranyl confer it a stable character to the complex formed in the τ-NaZP, that makes to this material appropriate to retain to the uranyl in solution to high ion forces and in acid media. (Author)

  5. 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

  6. Cowpea nodulation, biomass yield and nutrient uptake, as affected by biofertilizers and rhizobia, in a sodic soil amended with Acidithiobacillus - doi: 10.4025/actasciagron.v35i4.16994

    Directory of Open Access Journals (Sweden)

    Newton Pereira Stamford

    2013-05-01

    Full Text Available Sodic soils require application of amendments as gypsum and organic matter. Many types of compost have been tested in sodic soils reclamation; however, these materials often do not provide satisfactory pH reduction. A recent study reported effective effects applying mixture of gypsum and sulfur inoculated with Acidithiobacillus in sodic soils with high pH and exchangeable sodium, though the effects on plant parameters were not evaluated. The present study was conducted to verify the effects of BPK rock biofertilizers on nodulation, biomass yield and nutrient uptake in cowpea compared with mineral fertilizer after sodic soil amendment. The BPK biofertilizers and PK mineral fertilizer were applied at different rates, and plants were inoculated with effective rhizobia strains. A control that did not receive PK fertilization was included. The results indicated that gypsum and sulfur with Acidithiobacillus reduced the soil’s pH and the amount of soil exchangeable sodium. BPK rock biofertilizer increased cowpea nodulation, biomass yield and nutrient uptake. The native rhizobia in the soil exhibited effectiveness in cowpea growth; displaying similar results compared with the rhizobia inoculated plants. BPK biofertilizers may be used as alternative to mineral PK fertilizers in sodic soils after the application of gypsum and sulfur inoculated with Acidithiobacillus.

  7. Deep subsurface drip irrigation using coal-bed sodic water: Part I. Water and solute movement

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Carleton R; Breit, George N; Healy, Richard W; Zupancic, John W; Hammack, Richard

    2013-02-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300–480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  8. 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 ...

  9. Sustainable irrigation Agriculture in the Tarim River Basin of Western Xinjiang Province--A proposal for the extablishment of a Salinity Laboratory of P. R. China%中国新疆塔里木河流域的可持续灌溉农业--关于建立中国国家盐渍化研究实验室的建议

    Institute of Scientific and Technical Information of China (English)

    约瑟夫·沙赫维特; 周政一; 徐曼

    2000-01-01

    Based on the background information and the personal impression obtained during a short visit to Tarim River basin, a few problems may be defined and a proposal is presented for establishing a salinity laboratiory in the Tarim river basin of Xinjiang. The problems encountered in the Tarim river basin can be grouped into four categories: (1) Salt reclamation through leaching and resalinization following irrigation; (2) Sodicity (alkalinity) problems; (3) Impermeable subsoil layers; (4) Irrigation water salinity. In order to ensure a sustainable irrigation agriculture in Xinjiang, the water utilization efficiency for both irngation and leaching will have to be improved. The solution for the existing problems and the prevention of future problems for sustainable production requires good quantitative information. It is considered that to establish a salinity laboratory in the Tarim River basin will be not only immediately applicable to Xinjiang' s salinity problems, but its results will be valuable also for other arid regions suffering from the similar problems in China.

  10. 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.

  11. 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.

  12. 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.

  13. Saline groundwater in crystalline bedrock

    International Nuclear Information System (INIS)

    The State-of-art report describes research made on deep saline groundwaters and brines found in crystalline bedrock, mainly in site studies for nuclear waste disposal. The occurrence, definitions and classifications of saline groundwaters are reviewed with a special emphasis on the different theories concerning the origins of saline groundwaters. Studies of the saline groundwaters in Finland and Sweden have been reviewed more thoroughly. Also the mixing of different bodies of groundwaters, observations of the contact of saline groundwaters and permafrost, and the geochemical modelling of saline groundwaters as well as the future trends of research have been discussed. (orig.)

  14. The petrogenesis of sodic granites in the Niujuanzi area and constraints on the Paleozoic tectonic evolution of the Beishan region, NW China

    Science.gov (United States)

    Yu, Jiyuan; Guo, Lin; Li, Jianxing; Li, Yanguang; Smithies, Robert H.; Wingate, Michael T. D.; Meng, Yong; Chen, Shefa

    2016-07-01

    Ordovician to Devonian sodic granites dominate the newly recognized Luotuojuan composite granite in the Lebaquan-Luotuojuan-Niujuanzi region of Beishan, along the southern margin of the Central Asian Orogenic Belt in NW China. The granites include sodic (K2O/Na2O > 0.5) tonalites with low Y ( 68) that formed during at least two events at c. 435 and c. 370-360 Ma. Their compositions are consistent with high-pressure melting of basaltic crust, although relatively non-radiogenic Nd isotope compositions (εNd(t) + 0.9) require some crustal assimilation. The interpretation that these granites reflect melts of a subducted slab (i.e. adakite) is supported by independent local and regional geological evidence for an oceanic subduction-accretion setting, including a long history of calc-alkaline magmatism and the identification of a series of early Paleozoic ophiolite belts. Other sodic granites forming the Luotuojuan composite granite are mainly quartz-diorite and granodiorite formed between c. 391 and c. 360 Ma. These rocks are not adakites, having Sr concentrations and Sr/Y ratios too low and Y and Yb concentrations too high. They are low- to medium-K calc-alkaline rocks more typical of magmas derived through melting in a subduction modified mantle wedge. Compositional changes from sodic to potassic granites, over time frames consistent with subduction processes, suggest at least two separate cycles, or pulses, of hot subduction in the Lebaquan-Luotuojuan-Niujuanzi region. Although early Paleozoic adakites have been inferred to exist elsewhere in the Beishan region, many of the reported adakitic rocks have compositions inconsistent with melting of subducted oceanic lithosphere and so tectonic interpretation of hot subduction might not be valid in these cases. A study of regional granite data also shows not only that adakite magmatism does not extend into the Permian but that if subduction-accretion processes extended into the late Paleozoic, no typical subduction

  15. 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.

  16. Effect of desertification and soil salinity on land productivity in the Sudan

    International Nuclear Information System (INIS)

    Although the Sudan contains one of the largest reserves of cultivable and irrigable land in the world, desertification and salinization have had a severe effect on soil productivity. Irrational cultivation of marginal lands and the abuse of tractor power have led to severe erosion problems. Deforestation, overgrazing and the use of fire in land clearing have destroyed natural vegetation. Desertification has claimed most of the land between latitudes 150 and 170N and continues to move rapidly. The wild life habitants has been drastically altered with many species becoming extinct. Conflicts have arisen between nomads and cultivators. The government has thus developed a six year programme with emphasis on range seeding, afforestation, water conservation, fire control, sand dune stabilization and shelter belt development. Soil salinity and sodicity present both chemical and physical soil problems especially in irrigated regions. Since the Sudan is increasing its irrigated area from 2 to 4 million ha the problems will increase. Gypsum has not been effective in reclaimation but cultural practices such as ridge planting, timely seeding, and crop selection have shown promise. (author)

  17. Saline Systems highlights for 2006

    OpenAIRE

    DasSarma, Shiladitya

    2007-01-01

    Saline Systems is a journal devoted to both basic and applied studies of saline and hypersaline environments and their biodiversity. Here, I review the reports and commentaries published in the journal in 2006, including some exploring the geochemistry of saline estuaries, lakes, and ponds, others on the ecology and molecular biology of the indigenous halophilic organisms, and still others addressing the environmental challenges facing saline environments. Several studies are relevant to appl...

  18. 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

  19. 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...

  20. 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.

  1. 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

  2. Salinity control in a clay soil beneath an orchard irrigated with treated waste water in the presence of a high water table: A numerical study

    Science.gov (United States)

    Russo, David; Laufer, Asher; Bardhan, Gopali; Levy, Guy J.

    2015-12-01

    A citrus orchard planted on a structured, clay soil associated with a high water table, irrigated by drip irrigation system using treated waste water (TWW) and local well water (LWW) was considered here. The scope of the present study was to analyze transport of mixed-ion, interacting salts in a combined vadose zone-groundwater flow system focusing on the following issues: (i) long-term effects of irrigation with TWW on the response of the flow system, identifying the main factors (e.g., soil salinity, soil sodicity) that control these effects, and (ii) salinity control aiming at improving both crop productivity and groundwater quality. To pursue this two-fold goal, 3-D numerical simulations of field-scale flow and transport were performed for an extended period of time, considering realistic features of the soil, water table, crop, weather and irrigation, and the coupling between the flow and the transport through the dependence of the soil hydraulic functions, K(ψ) and θ(ψ), on soil solution concentration C, and sodium adsorption ratio, SAR. Results of the analyses suggest that in the case studied, the long-term effect of irrigation with TWW on the response of the flow system is attributed to the enhanced salinity of the TWW, and not to the increase in soil sodicity. The latter findings are attributed to: (i) the negative effect of soil salinity on water uptake, and the tradeoff between water uptake and drainage flux, and, concurrently, solute discharge below the root zone; and, (ii) the tradeoff between the effects of C and SAR on K(ψ) and θ(ψ). Furthermore, it was demonstrated that a data-driven protocol for soil salinity control, based on alternating irrigation water quality between TWW and desalinized water, guided by the soil solution salinity at the centroid of the soil volume active in water uptake, may lead to a substantial increase in crop yield, and to a substantial decrease in the salinity load in the groundwater.

  3. Genesis of the Madang Cenozoic sodic alkaline basalt in the eastern margin of the Tibetan Plateau and its continental dynamic implications

    Institute of Scientific and Technical Information of China (English)

    LAI; ShaoCong; ZHANG; GuoWei; LI; YongFei; QIN; JiangFeng

    2007-01-01

    The Madang Cenozoic sodic alkaline basalt occurred in the eastern margin of the Tibetan Plateau, where is a key tectonic transform region of Tibet, North China, and Yangtze blocks. The basalts are characterized by the variation in SiO2=42%―51%, Na2O/K2O>4, belonging to the sodic alkaline basalt series. The rocks are enriched in Ba, Th, Nb, Ta, relative to a slight depletion in K, Rb in the trace and rare earth element (REE) spider diagrams that are similar to the typical oceanic island alkaline basalt. The Sr-Nd-Pb isotopic compositions suggest that they are derived from a mixed mantle reservoir. The western Qinling-Songpan tectonic region was controlled by Tibet, North China and Yangtze blocks since Cenozoic, therefore, the region was in the stage of the substance converge from the mantle to upper crust, producing a mixed mantle reservoir in the studied area. The Madang basalts occurred in the specific tectonic background, they result from partial melting of a mixed asthenospheric mantle reservoir in the western Qinling-Songpan tectonic node.

  4. 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

  5. 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.

  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. Petrogenesis of Late Permian sodic metagranitoids in southeastern Korea: SHRIMP zircon geochronology and elemental and Nd-Hf isotope geochemistry

    Science.gov (United States)

    Cheong, Chang-sik; Kim, Namhoon; Kim, Jeongmin; Yi, Keewook; Jeong, Youn-Joong; Park, Chan-Soo; Li, Huai-kun; Cho, Moonsup

    2014-12-01

    One of the striking tectonomagmatic features recently found in southeastern Korea is the occurrence of ca. 250 Ma high-silica adakite. Sodic metagranitoids mainly consisting of tonalitic-trondhjemitic-granodioritic gneisses occur in the Andong-Cheongsong area adjacent to the Yeongdeok adakite site. To investigate temporal and petrogenetic relationships of these orthogneisses with the adakite, we conducted SHRIMP zircon U-Pb dating as well as elemental and Nd-Hf isotopic analyses. Zircon core ages of the orthogneisses (ca. 262-251 Ma) confirm the widespread occurrence of arc-related Late Permian magmatism in southeastern Korea. The Late Triassic (ca. 230 Ma) zircon overgrowths reflect a thermal overprint probably related to the initiation of another subduction system. The analyzed orthogneisses have major element compositions comparable to the Phanerozoic adakites and Archean TTG suite, such as high SiO2 (58.7-65.5 wt.%) and Al2O3 (17.1-19.1 wt.%) contents and Na2O/K2O ratios (1.83-4.95). However, their moderate Sr/Y (35-43) and La/Yb (14-53) ratios and negative Eu anomalies (Eu/Eu* = 0.75-0.95) are incompatible with the key features reported from the Yeongdeok adakite. Moreover, initial whole-rock εNd (-7.9 to -3.3) and zircon εHf (-0.3 ± 2.4) values of the orthogneisses negate a direct derivation from the subducted slab. Our elemental and Nd-Hf isotopic data collectively suggest that the protoliths of the tonalitic-trondhjemitic-granodioritic gneisses were generated by partial melting of mafic lower crust at depths shallower than the garnet stability field. Our Nd and Hf model ages of the gneisses, together with those previously reported from the Mesozoic granitoids indicate a selective involvement of young source materials along the margin of the Yeongnam massif. The Hf isotopic compositions of zircons from a trondhjemitic gneiss attest to the involvement of primitive melts during their crystallization. The ridge subduction and consequent development of a slab

  8. Sodium exclusion QTL associated with improved seedling growth in bread wheat under salinity stress.

    Science.gov (United States)

    Genc, Y; Oldach, K; Verbyla, A P; Lott, G; Hassan, M; Tester, M; Wallwork, H; McDonald, G K

    2010-09-01

    Worldwide, dryland salinity is a major limitation to crop production. Breeding for salinity tolerance could be an effective way of improving yield and yield stability on saline-sodic soils of dryland agriculture. However, this requires a good understanding of inheritance of this quantitative trait. In the present study, a doubled-haploid bread wheat population (Berkut/Krichauff) was grown in supported hydroponics to identify quantitative trait loci (QTL) associated with salinity tolerance traits commonly reported in the literature (leaf symptoms, tiller number, seedling biomass, chlorophyll content, and shoot Na(+) and K(+) concentrations), understand the relationships amongst these traits, and determine their genetic value for marker-assisted selection. There was considerable segregation within the population for all traits measured. With a genetic map of 527 SSR-, DArT- and gene-based markers, a total of 40 QTL were detected for all seven traits. For the first time in a cereal species, a QTL interval for Na(+) exclusion (wPt-3114-wmc170) was associated with an increase (10%) in seedling biomass. Of the five QTL identified for Na(+) exclusion, two were co-located with seedling biomass (2A and 6A). The 2A QTL appears to coincide with the previously reported Na(+) exclusion locus in durum wheat that hosts one active HKT1;4 (Nax1) and one inactive HKT1;4 gene. Using these sequences as template for primer design enabled mapping of at least three HKT1;4 genes onto chromosome 2AL in bread wheat, suggesting that bread wheat carries more HKT1;4 gene family members than durum wheat. However, the combined effects of all Na(+) exclusion loci only accounted for 18% of the variation in seedling biomass under salinity stress indicating that there were other mechanisms of salinity tolerance operative at the seedling stage in this population. Na(+) and K(+) accumulation appear under separate genetic control. The molecular markers wmc170 (2A) and cfd080 (6A) are expected to

  9. 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.

  10. Salinity driven oceanographic upwelling

    Science.gov (United States)

    Johnson, David H.

    1986-01-01

    The salinity driven oceanographic upwelling is maintained in a mariculture device that includes a long main duct in the general shape of a cylinder having perforated cover plates at each end. The mariculture device is suspended vertically in the ocean such that one end of the main duct is in surface water and the other end in relatively deep water that is cold, nutrient rich and relatively fresh in comparison to the surface water which is relatively warm, relatively nutrient deficient and relatively saline. A plurality of elongated flow segregating tubes are disposed in the main duct and extend from the upper cover plate beyond the lower cover plate into a lower manifold plate. The lower manifold plate is spaced from the lower cover plate to define a deep water fluid flow path to the interior space of the main duct. Spacer tubes extend from the upper cover plate and communicate with the interior space of the main duct. The spacer tubes are received in an upper manifold plate spaced from the upper cover plate to define a surface water fluid flow path into the flow segregating tubes. A surface water-deep water counterflow is thus established with deep water flowing upwardly through the main duct interior for discharge beyond the upper manifold plate while surface water flows downwardly through the flow segregating tubes for discharge below the lower manifold plate. During such counterflow heat is transferred from the downflowing warm water to the upflowing cold water. The flow is maintained by the difference in density between the deep water and the surface water due to their differences in salinity. The upwelling of nutrient rich deep water is used for marifarming by fertilizing the nutrient deficient surface water.

  11. Groundwater salinity and environmental change

    International Nuclear Information System (INIS)

    The accumulation and release of salinity from near surface environments takes place naturally as a result of climatic cycles and environmental change. Salinity stratification, both in the saturated and unsaturated zones of aquifers, may be used in certain circumstances to record past recharge events and periods of drought. Chloride, in conjunction with the stable isotopes δ18O, δ2H and other chemical and stable or radioactive indicator parameters, enables the origins of salinity and the timing of these events to be determined. Salinity may be used as a practical tool in water resource investigation to estimate recharge and discharge, to investigate palaeohydrology and in the understanding and management of groundwater in coastal regions. Human impacts have severely disturbed the natural salinity balance, especially in the past 100 years, and examples of human intervention are presented relating to dryland salinity, irrigation effects and overexploitation. (author)

  12. Soil hydraulic conductivity affected by slight saline water irrigation in North China%华北地区微咸水应用对土壤水力传导性能的影响

    Institute of Scientific and Technical Information of China (English)

    李法虎; 闫红; 庞昌乐; 夏强

    2013-01-01

      由于淡水资源短缺,中国华北地区微咸地下水灌溉面积逐年增多.该文通过室内土柱淋洗试验,研究了灌溉水盐分浓度和钠吸附比(SAR)对华北地区非碱土(可交换钠百分比 ESP0)和碱土(ESP30)饱和水力传导性能的影响.灌溉水盐浓度分别为2.5、10和25 mmolc/L,SAR 分别为0、10和30(mmolc/L)0.5.去离子(盐浓度0)作为对照处理.试验包括2个土壤碱度、9个灌溉水质组合和1个去离子水处理,共20个试验处理.试验结果显示,非碱土和碱土对微咸水应用的反应机理以及反应程度不同.当黏粒弥散程度较弱时,上部土壤的饱和水力传导度显著大于下层土壤;反之,则各层土壤的水力传导度均较小.在试验水质条件下,非碱土的平均饱和水力传导度的变化范围为0.75~13.25 cm/h,而碱土的变化范围为0.06~6.50 cm/h.碱土的稳定饱和水力传导度随着灌溉水盐浓度的增加或/和 SAR 的减小而增大,但在非碱土中稳定饱和水力传导度的变化规律与此基本相反.试验结果对合理应用微咸水灌溉非碱土和碱土具有指导意义.%The area irrigated with slight saline groundwater increases in North China because of fresh water shortage. The effects of salt concentration and sodium adsorption ratio (SAR) in irrigation water on saturated hydraulic conductivity of nonsodic (exchangeable sodium percentage ESP0) and sodic (ESP30) soils in North China were studied by soil column experiments in laboratory. The designed salt concentrations in irrigation water were 2.5, 10, and 25 mmolc/L, and its SARs were 0, 10, and 30 (mmolc/L)0.5, respectively. Irrigation with distilled water (salt concentration0) also was conducted as a control treatment. The experiments included 2 soil sodicity levels, 9 irrigation water qualities, and one distilled water treatment, and total experimental treatments were 20. Experimental results demonstrated that saturated hydraulic

  13. Water-Extractable Carbon Pools and Microbial Biomass Carbon in Sodic Water-Irrigated Soils Amended with Gypsum and Organic Manures

    Institute of Scientific and Technical Information of China (English)

    O.P.CHOUDHARY; J.K.GILL; BIJAY-SINGH

    2013-01-01

    Microbial biomass carbon (MBC),a small fraction of soil organic matter,has a rapid turnover rate and is a reservoir of labile nutrients.The water-extractable carbon pools provide a fairly good estimate of labile C present in soil and can be easily quantified.Changes in soil MBC and water-extractable organic carbon pools were studied in a 14-year long-term experiment in plots of rice-wheat rotation irrigated with canal water (CW),sodic water (SW,10-12.5 mmolc L-1 residual sodium carbonate),and SW amended with gypsum with or without application of organic amendments including farmyard manure (FYM),green manure (GM),and wheat straw (WS).Irrigation with SW increased soil exchangeable sodium percentage by more than 13 times compared to irrigation with CW.Sodic water irrigation significantly decreased hot water-extractable organic carbon (HWOC) from 330 to 286 mg kg-1 soil and cold water-extractable organic carbon (CWOC) from 53 to 22 mg kg-1 soil in the top 0-7.5 cm soil layer.In the lower soil layer (7.5-15 cm),reduction in HWOC was not significant.Application of gypsum alone resulted in a decrease in HWOC in the SW plots,whereas an increase was recorded in the SW plots with application of both gypsum and organic amendments in both the soil layers.Nevertheless,application of gypsum and organic amendments increased the mean CWOC as compared with application of gypsum alone.CWOC was significantly correlated with MBC but did not truly reflect the changes in MBC in the treatments with gypsum and organic amendments applied.For the treatments without organic amendments,HWOC was negatively correlated with MBC (r =-0.57*)in the 0-7.5 cm soil layer,whereas for the treatments with organic amendments,both were positively correlated.Irrigation with SW significantly reduced the rice yield by 3 t ha-1 and the yield of rice and wheat by 5 t ha-1 as compared to irrigation with canal water.Application of amendments significantly increased rice and wheat yields.Both the rice yield and

  14. 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

  15. Late sodic metasomatism evidences in bimodal volcanic rocks of the Acampamento Velho Alloformation, Neoproterozoic III, southern Brazil

    Directory of Open Access Journals (Sweden)

    Delia Del Pilar M. de Almeida

    2007-12-01

    Full Text Available A mineralogical study was carried out in mafic and felsic volcanic rocks of the Acampamento Velho Alloformation at Cerro do Bugio, Perau and Serra de Santa Bárbara areas (Camaquã Basin in southern Brazil. The Acampamento Velho bimodal event consists of two associations: lower mafic at the base and upper felsic at the top. Plagioclase and alkali-feldspar were studied using an electronic microprobe, and magnetite, ilmenite, rutile, illite and alkali-feldspar were investigated through scanning electron microscopy. The rocks were affected by a process of late sodic autometasomatism. In mafic rocks, Ca-plagioclase was transformed to albite and pyroxenes were altered. In felsic rocks, sanidine was partially pseudomorphosed, generating heterogeneous alkali-feldspar. In this association, unstable Ti-rich magnetite was replaced by rutile and ilmenite. In mafic rocks, the crystallization sequence was: (1 Ti-rich magnetite (?, (2 pyroxene and Ca-plagioclase, (3 albite (alteration to Ca-plagioclase, (4 sericite, chlorite and calcite (alteration to pyroxene, and kaolinite (alteration to plagioclase/albite. In felsic rocks: (1 zircon, (2 Ti-rich magnetite, (3 sanidine, (4 quartz. The introduction of late Na-rich fluids, generated the formation of (5 heterogeneous alkali-feldspar, (6 ilmenite and rutile from the Ti-rich magnetite, (7 albite in the spherulites. Finally, alteration of sanidine, vitroclasts and pumice to (8 illite.Um estudo mineralógico de detalhe foi realizado nas rochas vulcânicas da Aloformação Acampamento Velho nos Cerros do Bugio, Perau e Serra de Santa Bárbara (Bacia do Camaquã, sudeste do Brasil. Este evento bimodal é constituído por duas associações: máfica inferior na base e félsica superior no topo. Foram estudados grãos de plagioclásio e feldspato alcalino com o uso de microssonda eletrônica, sendo que, magnetita,ilmenita, rutilo e ilita além de feldspato alcalino foram pesquisados através do microscópio eletr

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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 ...

  3. 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...

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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. 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.

  7. 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.

  8. Modeling of groundwater level fluctuations using dendrochronology in alluvial aquifers

    Science.gov (United States)

    Gholami, V.; Chau, K. W.; Fadaee, F.; Torkaman, J.; Ghaffari, A.

    2015-10-01

    Groundwater is the most important water resource in semi-arid and arid regions such as Iran. It is necessary to study groundwater level fluctuations to manage disasters (such as droughts) and water resources. Dendrochronology, which uses tree-rings to reconstruct past events such as hydrologic and climatologic events, can be used to evaluate groundwater level fluctuations. In this study, groundwater level fluctuations are simulated using dendrochronology (tree-rings) and an artificial neural network (ANN) for the period from 1912 to 2013. The present study was undertaken using the Quercus Castaneifolia species, which is present in an alluvial aquifer of the Caspian southern coasts, Iran. A multilayer percepetron (MLP) network was adopted for the ANN. Tree-ring diameter and precipitation were the input parameters for the study, and groundwater levels were the outputs. After the training process, the model was validated. The validated network and tree-rings were used to simulate groundwater level fluctuations during the past century. The results showed that an integration of dendrochronology and an ANN renders a high degree of accuracy and efficiency in the simulation of groundwater levels. The simulated groundwater levels by dendrochronology can be used for drought evaluation, drought period prediction and water resources management.

  9. Influence of Alluvial Morphology on Upscaled Hydraulic Conductivity.

    Science.gov (United States)

    Jha, Sanjeev Kumar; Mariethoz, Gregoire; Mathews, George; Vial, John; Kelly, Bryce F J

    2016-05-01

    The hydraulic conductivity of aquifers is a key parameter controlling the interactions between resource exploitation activities, such as unconventional gas production and natural groundwater systems. Furthermore, this parameter is often poorly constrained by typical data used for regional groundwater modeling and calibration studies performed as part of impact assessments. In this study, a systematic investigation is performed to understand the correspondence between the lithological descriptions of channel-type formation and the bulk effective hydraulic conductivities at a larger scale (Kxeff , Kyeff , and Kzeff in the direction of channel cross section, along the channel and in the vertical directions, respectively). This will inform decisions on what additional data gathering and modeling of the geological system can be performed to allow the critical bulk properties to be more accurately predicted. The systems studied are conceptualized as stacked meandering channels formed in an alluvial plain, and are represented as two facies. Such systems are often studied using very detailed numerical models. The main factors that may influence Kxeff , Kyeff , and Kzeff are the proportion of the facies representing connected channels, the aspect ratio of the channels, and the difference in hydraulic conductivity between facies. Our results show that in most cases, Kzeff is only weakly dependent on the orientations of channelized structures, with the main effects coming from channel aspect ratio and facies proportion. PMID:26479727

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

    Energy Technology Data Exchange (ETDEWEB)

    Handford, C.R.

    1987-05-01

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

  11. Saline agriculture in Mediterranean environments

    Directory of Open Access Journals (Sweden)

    Albino Maggio

    2011-03-01

    Full Text Available Salinization is increasingly affecting world's agricultural land causing serious yield loss and soil degradation. Understanding how we could improve crop productivity in salinized environments is therefore critical to meet the challenging goal of feeding 9.3 billion people by 2050. Our comprehension of fundamental physiological mechanisms in plant salt stress adaptation has greatly advanced over the last decades. However, many of these mechanisms have been linked to salt tolerance in simplified experimental systems whereas they have been rarely functionally proven in real agricultural contexts. In-depth analyses of specific crop-salinity interactions could reveal important aspects of plant salt stress adaptation as well as novel physiological/agronomic targets to improve salinity tolerance. These include the developmental role of root vs. shoot systems respect to water-ion homeostasis, morphological vs. metabolic contributions to stress adaptation, developmental processes vs. seasonal soil salinity evolution, residual effects of saline irrigation in non-irrigated crops, critical parameters of salt tolerance in soil-less systems and controlled environments, response to multiple stresses. Finally, beneficial effects of salinization on qualitative parameters such as stress-induced accumulation of high nutritional value secondary metabolites should be considered, also. In this short review we attempted to highlight the multifaceted nature of salinity in Mediterranean agricultural systems by summarizing most experimental activity carried out at the Department of Agricultural Engineering and Agronomy of University of Naples Federico II in the last few years.

  12. 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.

  13. The Mediterranean salinity crisis

    Energy Technology Data Exchange (ETDEWEB)

    Hsue, K.J.

    1988-08-01

    That the Mediterranean Sea underwent a salinity crisis during the Miocene (Messinian) is proven by the 1970 JOIDES deep sea drilling expedition. Subsequent work by ocean drilling and by studies on land have recorded the history of this crisis. Based upon the deep desiccated-basin model, the use of event-stratigraphy, calibrated by strontium-isotope dating and magnetostratigraphy, has enabled them to decipher the following events between 6.0 and 5.1 Ma: (1) deposition of marine diatom-rich sediments in a partially restricted basin, (2) first desiccation of the Mediterranean when Calcare di base was deposited at a time of isolation from the Atlantic because of a glacial eustatic drop of sea level, (3) influx of marine waters through southern Spanish basins to furnish brines for the deposition of the main salt, (4) Intra-Messinian desiccation, as evidenced by the erosional unconformity above the lower evaporite, (5) Intra-Messinian denudation, when reefs grew on Cyprus and marine sediments were deposited in basins, (6) frequency isolations due to oscillating sea level, when the upper evaporite was deposited, (7) Lago mare, formation of freshwater and brackish lakes due to influx of Paratethys water, (8) opening of the Gibraltar and Pliocene inundation of the Mediterranean.

  14. 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

  15. 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

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

    Science.gov (United States)

    Młynarek, Zbigniew; Stefaniak, Katarzyna; Wierzbicki, Jedrzej

    2012-10-01

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

  17. 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.

  18. 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.

  19. NOAA Average Annual Salinity (3-Zone)

    Data.gov (United States)

    California Department of Resources — The 3-Zone Average Annual Salinity Digital Geography is a digital spatial framework developed using geographic information system (GIS) technology. These salinity...

  20. 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

  1. Finite Amplitude Bars in Mixed Bedrock-Alluvial River Channel Bends

    Science.gov (United States)

    Nelson, P. A.; Seminara, G.; Bolla Pittaluga, M.

    2012-12-01

    A common and well-understood feature of alluvial rivers is the tendency for channel curvature to induce bed deformations, producing a point bar on the inner bank and scour on the outer bank. However, for mixed bedrock-alluvial rivers, where the amount of sediment supplied from upstream is less than the local sediment transport capacity, our understanding of this phenomenon is less clear. Our goal here is to develop a theory capable of answering the question: How does channel curvature influence sediment deposition and bedrock exposure in mixed bedrock-alluvial rivers? We have developed a nonlinear asymptotic theory of fully developed flow and bed topography in a wide channel of constant curvature to describe finite-amplitude perturbations of bottom topography, subject to an inerodible bedrock layer. The flow field is evaluated at leading order of approximation as a slowly varying sequence of locally uniform flows, slightly perturbed by a weak curvature-induced secondary flow. Using the constraint of constant fluid discharge, we calculate an analytical solution for the cross-sectional profile of flow depth and bed topography, and we determine the average slope in the bend necessary to transport the sediment supplied from a straight, alluvial, upstream reach. Both fully-alluvial bends and bends with partial bedrock exposure are shown to require a larger average slope than a straight upstream reach; the relative slope increase is much larger for partially alluviated bends. Curvature has a strong effect on the characteristics of the point bars in mixed bedrock-alluvial channels, with higher curvature bends exhibiting bars of larger amplitude and more bedrock exposure through the cross section. Differences in the relative roughness of sediment and bedrock have a smaller, secondary effect on point bar characteristics. This theory can potentially be extended to the not fully developed case, and should ultimately lead to an improved understanding of the formation of

  2. Geohydrology and saline ground-water discharge to the South Fork Ninnescah River in Pratt and Kingman Counties, south-central Kansas

    Science.gov (United States)

    Gillespie, Joe B.; Hargadine, G.D.

    1994-01-01

    Saline ground water discharges to the South Fork Ninnescah River in Pratt and Kingman Counties from the adjacent alluvial aquifer. Electromagnetic terrain surveys in this area indicated that the saline ground water is entering the river in intermittent reaches along the channel. The chloride concentration in the river near Murdock exceeds 250 milligrams per liter 75 percent of the time. During base flow in November 1988, stream discharge increased 67 cubic feet per second, and the chloride concentration increased 360 milligrams per liter from Pratt to the Pratt-Kingman County line. The chloride load to the river along this reach was 82 tons per day. The source of saline water probably is dissolution of salt in the Permian rocks, about 600 feet below land surface. Subsequent subsidence and collapse of Permian rocks into salt-dissolution cavities probably has caused fracturing in overlying Permian rocks. Brine moves upward through the Permian rocks and discharges into the alluvial aquifer. The brine discharge to the alluvium is about 0.7 cubic foot per second. In the area of major saline-water discharge to the river, the fluid-potential levels in the Permian rocks are higher than fluid-potential levels in the alluvial aquifer. Several methods for reducing the saline ground-water discharge to the South Fork Ninnescah River have been considered. The most effective of these methods appears to be interception of brine flow in the Permian rocks by pumping of relief wells. Brine could be disposed by injection into deeper formations, by storage in evaporation reservoirs, or by desalinization.

  3. NOAA NOS SOS, EXPERIMENTAL - Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have salinity data. *These services are for testing and evaluation use...

  4. World Ocean Atlas 2005, Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  5. Stochastic Modeling of Soil Salinity

    CERN Document Server

    Suweis, S; Van der Zee, S E A T M; Daly, E; Maritan, A; Porporato, A; 10.1029/2010GL042495

    2012-01-01

    A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a single stochastic differential equation driven by multiplicative Poisson noise. The novel analytical solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In particular, they show the existence of two distinct regimes, one where the mean salt mass remains nearly constant (or decreases) with increasing rainfall frequency, and another where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in long-term soil salinization trend...

  6. Reliktni vršaji kontaktnega krasa severozahodnega dela Matarskega podolja = Relict alluvial fans of northwest part of Matarsko podolje

    Directory of Open Access Journals (Sweden)

    Uroš Stepišnik

    2007-01-01

    Full Text Available Several types of contact karst are found within the Slovenian karst, but the most common isthe ponor type, which appears between flysch and limestone. The most extensive contact ofthis type is in western Slovenia, in the area of Matarsko podolje, where a variety of typicalcontact karst depression features can be found. Relict alluvial fans on contact karst are theresult of the gradual denudation of alluvial cover from flysch and chemical denudation ofcarbonate bedrock in the area of alluvial fans. Geomorphologic features and processes onalluvial fans, and the influences of alluvial fans on the development of local karst have beeninvestigated in detail.

  7. Water sources accessed by arid zone riparian trees in highly saline environments, Australia.

    Science.gov (United States)

    Costelloe, Justin F; Payne, Emily; Woodrow, Ian E; Irvine, Elizabeth C; Western, Andrew W; Leaney, Fred W

    2008-05-01

    The flow regimes of arid zone rivers are often highly variable, and shallow groundwater in the alluvial aquifers can be very saline, thus constraining the availability and quality of the major water sources available to riparian trees-soil water, shallow groundwater and stream water. We have identified water sources and strategies used by riparian trees in more highly saline and arid conditions than previously studied for riparian trees of arid zone rivers. Our research focused on the riparian species Eucalyptus coolabah, one of the major riparian trees of ephemeral arid zone rivers in Australia. The water sources available to this riparian tree were examined using delta(18)O isotope data from xylem, soil water, groundwater and surface water. Additionally, soil chloride and matric potential data were used to infer zones of water availability for root uptake. Despite the saline conditions, the trees used a mixture of soil water and groundwater sources, but they did not use surface water directly. The study identified three strategies used to cope with typically high groundwater and soil water salinities. Firstly, the trees preferentially grow in zones of most frequent flushing by infiltrating streamflow, such as the bank-tops of channels. Secondly, the trees limit water use by having low transpiration rates. Thirdly, the trees are able to extract water at very low osmotic potentials, with water uptake continuing at chloride concentrations of at least 20,000-30,000 mg L(-1). PMID:18270743

  8. 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

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

    Directory of Open Access Journals (Sweden)

    M. Cavalli

    2008-04-01

    Full Text Available 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 used to calculate a shaded relief map, plan curvature and an index of topographic roughness based on the standard deviation of elevation within a moving window. The surface complexity of the alluvial fan, also influenced by human activities, clearly arose from the analysis. The surface roughness, defined here as the local topography variability, is compared with a previous classification of the fan surface based on field surveys. The results demonstrate that topographic analysis of ground based LiDAR DTM can be a useful tool to objectively investigate fan morphology and hence alluvial fan hazard assessment.

  10. 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

  11. Isotopic and hydrochemical approaches to study the salinity affected areas in Amarawati districts of Maharashtra State in India

    International Nuclear Information System (INIS)

    Inland salinity of groundwater in parts of Purna alluvial tract is a very interesting phenomenon because it lies 800 km away from seacoast and no remnants of irrigation practices have been observed. Out of the total area of about 7500 km2, the salinity affected area is about 2956 km2, which is confined mainly in the northern and central parts of the Purna alluvium in Amravati, Akola and Buldhana districts of Maharashtra. The thickness of saline aquifer varies from 50 m to 420 m deepest in the basin. Different types of land forms, viz. older flood plain, piedmont zone, alluvial fans, pediplain with alluvial cover, interfans, dissected alluvial platform are identified within the alluvial plain: Rock types exposed in the area are Upper Gondwana, Infra trappean bed, Deccan trap and Quaternary sediments. Quaternary sediments cover much of the area while basin margins are mainly of Deccan Trap. The Groundwater Surveys and Development Agency (GSDA) of Maharashtra State carried out a 'Induced Recharge Project', whereby the river water of good quality was intended to be used for recharging the groundwater in the aquifers adjoining the river courses. A large number of wells were drilled along the river banks and operated to create a reverse groundwater level gradient. In the present paper presents the results of the work that was carried out to understand the causes of groundwater salinity in parts of the Purna river basin using chemical and isotopic approaches. Also the evaluation of the performance of the wells drilled and being operated under an ongoing induced recharge project of the GSDA is presented. A detailed study of available information on the hydrogeology, hydrochemistry, soil characteristics, hydrometeorology, land use pattern, and hydrology was carried out prior to the collection of river and groundwater samples from 37 locations in the study area. The samples were subjected to hydrochemical analyses for major ions such as Ca2+, Mg2+, Na+, K+, HCO3-, SO42-, and

  12. 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.

  13. 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.

  14. 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.

  15. In situ determination of salinity by PGNAA.

    Science.gov (United States)

    Borsaru, M; Smith, C; Merritt, J; Aizawa, T; Rojc, A

    2006-05-01

    Salinity is a very important environmental issue all around the world. In many cases salinity was produced from human activities like farming and mining. Different soluble salts contribute to salinity, however, NaCl is the most common salt producing salinity. This work deals with the application of the prompt gamma neutron activation analysis (PGNAA) technique for in situ determination of salinity. The technique is based on the measurement of chlorine, a component of the common salt, by PGNAA. PMID:16448819

  16. In situ determination of salinity by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia)]. E-mail: mihai.borsaru@csiro.au; Smith, C. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia); Merritt, J. [Anglo Coal (Capcoal Management) Pty. Ltd., PMB, Middlemount. Qld. 4746 (Australia); Aizawa, T. [Suncoh Consultants Co., Ltd, 1-8-9, Kameido, Koto-Ku, Tokyo, 136-8522 (Japan); Rojc, A. [CSIRO Exploration and Mining, P.O. Box 883, Kenmore, Qld. 4069 (Australia)

    2006-05-15

    Salinity is a very important environmental issue all around the world. In many cases salinity was produced from human activities like farming and mining. Different soluble salts contribute to salinity, however, NaCl is the most common salt producing salinity. This work deals with the application of the prompt gamma neutron activation analysis (PGNAA) technique for in situ determination of salinity. The technique is based on the measurement of chlorine, a component of the common salt, by PGNAA.

  17. In situ determination of salinity by PGNAA

    International Nuclear Information System (INIS)

    Salinity is a very important environmental issue all around the world. In many cases salinity was produced from human activities like farming and mining. Different soluble salts contribute to salinity, however, NaCl is the most common salt producing salinity. This work deals with the application of the prompt gamma neutron activation analysis (PGNAA) technique for in situ determination of salinity. The technique is based on the measurement of chlorine, a component of the common salt, by PGNAA

  18. 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.

  19. 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...

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

    OpenAIRE

    Hamer, de, Wouter; D. Love; R. Owen; M. J. Booij; 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 and after implementation of two storage capacity measures. These measures are heightening the spillway of the ‘Mnyabezi 27’ dam and constructing a sand storage dam in the alluvial aquifer of the M...

  1. Narrow and broad senses on salinity scale

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The narrow sense and applicable limit of Practical Salinity Scale 1978 (PSS78) and volumetric titration using silver nitrate to measure the salinity of non-conservative oceanwater are discussed.The salinity obtained by electrical conductivity method and chlorinity salinity method obviously deviates from the absolute salinity (SA). The Density Salinity Scale (DSS98) proposed by the writers can be extensively used in conservative and non-conservative water samples.The merits of the density salinity scale are as follows,(1) The Density Salinity Scale is only related to seawater mass and its buoyant effect, and is not influenced by the variation in seawater composition, and therefore, has high reliability, and repeatability for salinity determination.(2) The salinity values measured by the DSS98 have a conservative property. For oceanwater samples the salinity values are the same as those determined by the PSS78; for non-conservative water samples (e.g. samples from industrial sources), the salinity values are close to the absolute salinity values in comparison with those measured by the PSS78 and the Knudsen method.(3)For a solution with given solute mass, the solution concentration can be converted into the corresponding salinity by the Density Salinity Scale using the expansion coefficient of the solution and the calibration coefficient of the partial molar volume of the solute.

  2. Alluvial deposits and plant distribution in an Amazonian lowland megafan

    Science.gov (United States)

    Zani, H.; Rossetti, D.; Cremon; Cohen, M.; Pessenda, L. C.

    2012-12-01

    A large volume of sandy alluvial deposits (> 1000 km2) characterizes a flat wetland in northern Amazonia. These have been recently described as the sedimentary record of a megafan system, which have a distinct triangular shape produced by highly migratory distributary rivers. The vegetation map suggests that this megafan is dominated by open vegetation in sharp contact with the surround rainforest. Understanding the relationship between geomorphological processes and vegetation distribution is crucial to decipher and conserve the biodiversity in this Amazonian ecosystem. In this study we interpret plant dynamics over time, and investigate its potential control by sedimentary processes during landscape evolution. The study area is located in the Viruá National Park. Two field campaigns were undertaken in the dry seasons of 2010 and 2011 and the sampling sites were selected by combining accessibility and representativeness. Vegetation contrasts were recorded along a transect in the medial section of the Viruá megafan. Due to the absence of outcrops, samples were extracted using a core device, which allowed sampling up to a depth of 7.5 m. All cores were opened and described in the field, with 5 cm3 samples collected at 20 cm intervals. The δ13C of organic matter was used as a proxy to distinguish between C3 and C4 plant communities. The chronology was established based on radiocarbon dating. The results suggest that the cores from forested areas show the most depleted values of δ13C, ranging from -32.16 to -27.28‰. The δ13C curve in these areas displays typical C3 land plant values for the entire record, which covers most of the Holocene. This finding indicates that either the vegetation remained stable over time or the sites were dominated by aquatic environments with freshwater plants before forest establishment. The cores from the open vegetation areas show a progressive upward enrichment in δ13C values, which range from -28.50 to -19.59‰. This trend is

  3. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins

    Directory of Open Access Journals (Sweden)

    Sommer Carlos A.

    2006-01-01

    Full Text Available The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources.

  4. The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins.

    Science.gov (United States)

    Sommer, Carlos A; Lima, Evandro F; Nardi, Lauro V S; Liz, Joaquim D; Waichel, Breno L

    2006-09-01

    The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and calc-alkaline to shoshonitic and ended with a silica-saturated sodic alkaline magmatism, and its evolution were developed during at least 60 Ma. The compositional variation and evolution of post-collisional magmatism in southern Brazil are interpreted as the result mainly of melting of a heterogeneous mantle source, which includes garnet-phlogopite-bearing peridotites, veined-peridotites with abundant hydrated phases, such as amphibole, apatite and phlogopite, and eventually with the addition of an asthenospheric component. The subduction-related metasomatic character of post-collisional magmatism mantle sources in southern Brazil is put in evidence by Nb-negative anomalies and isotope features typical of EM1 sources. PMID:16936944

  5. 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.

  6. Productive use of saline lands

    International Nuclear Information System (INIS)

    Water is essential for life, and not least for agricultural activity. It interacts with solar energy to determine the climate of the globe, and its interaction with carbon dioxide inside a plant results in photosynthesis on which depends survival of all life. Much of the water available to man is used for agriculture and yet its usage has not been well managed. One result has been the build up of soil salinity. The Department of Technical Co-operation is sponsoring a programme, with technical support from the Department of Research and Isotopes, to make more productive use of salt-affected land and to limit future build up of salinity. (IAEA)

  7. Texture and depositional history of near-surface alluvial deposits in the central part of the western San Joaquin Valley, California

    Science.gov (United States)

    Laudon, Julie; Belitz, Kenneth

    1989-01-01

    Saline conditions and associated high levels of selenium and other soluble trace elements in soil, shallow ground water, and agricultural drain water of the western San Joaquin Valley, California, have prompted a study of the texture of near-surface alluvial deposits in the central part of the western valley. Texture is characterized by the percentage of coarse-grained sediment present within a specified subsurface depth interval and is used as a basis for mapping the upper 50 feet of deposits. Resulting quantitative descriptions of the deposits are used to interpret the late Quaternary history of the area. Three hydrogeologic units--Coast Range alluvium, flood-basin deposits, and Sierran sand--can be recognized in the upper 50 feet of deposits in the central part of the western San Joaquin Valley. The upper 30 feet of Coast Range alluvium and the adjacent 5 to 35 feet of flood-basin deposits are predominantly fine grained. These fine-grained Coast Range deposits are underlain by coarse-grained channel deposits. The fine-grained flood basin deposits are underlain by coarse-grained Sierran sand. The extent and orientation of channel deposits below 20 feet in the Coast Range alluvium indicate that streams draining the Coast Range may have been tributary to the axial stream that deposited the Sierran sand and that streamflow may have been to the southeast. The fining-upward stratigraphic sequence in the upper 50 feet of deposits and the headward retreat of tributary stream channels from the valley trough with time support a recent hypothesis of climatic control of alluviation in the western San Joaquin Valley.

  8. 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

  9. 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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Majkić-Dursun Brankica

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Gatton is an important agricultural area for Queensland where about 40% of its vegetables needs are produced using groundwater as the main source. An alluvial Aquifer is located about 30m beneath the layers of alluvial sediments ranging from black soils of volcanic origin on top, layers of alluvial sands, clays and beds of sand and gravel. The leakage of creek flows has been considered to be the main source of recharge to this aquifer. A number of weirs have been built across the Lockyer and Laidley creeks to allow surface water to infiltrate through the beds when the creeks flow. Water levels in bores in a section located in the middle of the alluvial plain (Crowley Vale) have been declining for the last 20 years with little or no success in recharging from the creeks. Acute water shortages have been experienced in the Gatton area during the droughts of 1980-81, 1986-87 and 1994-97. Naturally occurring stable isotopes, 2H, 180 and 13C as well as radioisotopes 3H and 14C have been used to delineate sources of recharge and active recharge areas. Tritium tracing of soil moisture in the unsaturated soil was also used to determine direct infiltration rates

  13. Hydrochemical processes in a shallow coal seam gas aquifer and its overlying stream–alluvial system: implications for recharge and inter-aquifer connectivity

    International Nuclear Information System (INIS)

    Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO3–Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

  14. Mycelial bacteria of saline soils

    Science.gov (United States)

    Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

    2008-10-01

    The actinomycetal complexes of saline soils comprise the representatives of the Streptomyces and Micromonospora genera, the number of which are hundreds and thousands of CFU/g soil. Complexes of mycelial bacteria in saline soils are poorer in terms of number (by 1-3 orders of magnitude) and taxonomic composition than the complexes of the zonal soil types. A specific feature of the actinomycetal complexes of saline soils is the predominance of halophilic, alkaliphilic, and haloalkaliphilic streptomycetes that well grow at pH 8-9 and concentrations of NaCl close to 5%. Actinomycetes in saline soils grow actively, and the length of their mycelium reaches 140 m in 1 gram of soil. The haloalkaliphilic streptomycetes grow fast and inhibit the formation of spores at pH 9 and high concentrations of salts (Na2SO4 and MgCl2, 5%) as compared to their behavior on a neutral medium with a salt concentration of 0.02%. They are characterized by the maximal radial growth rate of colonies on an alkaline medium with 5% NaCl.

  15. 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

  16. Bulk Moisture and Salinity Sensor

    Science.gov (United States)

    Nurge, Mark; Monje, Oscar; Prenger, Jessica; Catechis, John

    2013-01-01

    Measurement and feedback control of nutrient solutions in plant root zones is critical to the development of healthy plants in both terrestrial and reduced-gravity environments. In addition to the water content, the amount of fertilizer in the nutrient solution is important to plant health. This typically requires a separate set of sensors to accomplish. A combination bulk moisture and salinity sensor has been designed, built, and tested with different nutrient solutions in several substrates. The substrates include glass beads, a clay-like substrate, and a nutrient-enriched substrate with the presence of plant roots. By measuring two key parameters, the sensor is able to monitor both the volumetric water content and salinity of the nutrient solution in bulk media. Many commercially available moisture sensors are point sensors, making localized measurements over a small volume at the point of insertion. Consequently, they are more prone to suffer from interferences with air bubbles, contact area of media, and root growth. This makes it difficult to get an accurate representation of true moisture content and distribution in the bulk media. Additionally, a network of point sensors is required, increasing the cabling, data acquisition, and calibration requirements. measure the dielectric properties of a material in the annular space of the vessel. Because the pore water in the media often has high salinity, a method to measure the media moisture content and salinity simultaneously was devised. Characterization of the frequency response for capacitance and conductance across the electrodes was completed for 2-mm glass bead media, 1- to 2-mm Turface (a clay like media), and 1- to 2-mm fertilized Turface with the presence of root mass. These measurements were then used to find empirical relationships among capacitance (C), the dissipation factor (D), the volumetric water content, and the pore water salinity.

  17. INTEGRATING DESALINATION AND AGRICULTURAL SALINITY CONTROL ALTERNATIVES

    Science.gov (United States)

    The cost-effectiveness relationships for various agricultural and desalination alternatives for controlling salinity in irrigation return flows are developed. Selection of optimal salinity management strategies on a river basin scale is described as a problem of integrating optim...

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

    DEFF Research Database (Denmark)

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

    measurements were used to investigate on a local scale, indications of surface water/ groundwater exchange from electrical resistivity anomalies coincident with alluvial fans and flood plains as deduced from the aerial electrical resistivity result. New and innovative geophysical data inversion schemes were...... in order to come up with sustainable water resources management practices that are applicable to arid and semi-arid sedimentary basins in general and the Machile-Zambezi Basin in particular within the broader context of the Kalahari Basin of southern Africa. This will make it possible to project...... to map the spatial distribution of apparent electrical resistivity on a regional scale in order to obtain a regional overview of groundwater salinization based on electrical resistivity correlation. Furthermore, ground based transient electromagnetic soundings and direct current and induced polarization...

  19. Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium

    Science.gov (United States)

    Bern, Carleton R.; Engle, Mark A.; Boehlke, Adam R.; Zupancic, John W.

    2013-01-01

    A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached from soil by application of the CBM water and traces native salt mobilization to groundwater. Resulting selenium concentrations in groundwater at this alluvial site were generally low (0.5–23 μg/L) compared to Wyoming’s agricultural use suitability standard (20 μg/L).

  20. Saline water irrigation for crop production

    International Nuclear Information System (INIS)

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation

  1. 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

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

    Science.gov (United States)

    Mandlburger, Gottfried; Wieser, Martin; Pfennigbauer, Martin

    2015-04-01

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

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

    Science.gov (United States)

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

    2006-12-01

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

  4. The Aquarius Salinity Retrieval Algorithm

    Science.gov (United States)

    Meissner, Thomas; Wentz, Frank; Hilburn, Kyle; Lagerloef, Gary; Le Vine, David

    2012-01-01

    The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration [2] converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to molecular oxygen, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind, which is addressed in more detail in section 3. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water [3], [4] and an auxiliary field for the sea surface temperature. In the current processing only v-pol TB are used for this last step.

  5. LC土壤改良剂对土壤盐碱及大白菜生长的影响%Effect of LC Soil Conditioner on Saline-Sodic Soil and the Growth of Chinese Cabbage

    Institute of Scientific and Technical Information of China (English)

    于彩虹; 李秀文; 董荣芬

    2004-01-01

    进行了LC土壤改良剂对盐碱土壤的改良及对大白菜出苗、生长、产量的影响效果试验.结果表明,LC土壤改良剂对降低土壤耕层(0~40 cm)可溶性盐效果明显;在提高大白菜出苗率和产量上有一定作用.同时探讨了LC土壤改良剂施用量.

  6. Correção de solos salino-sódicos pela aplicação de gesso mineral Reclamation of saline-sodic soils by application of mineral gypsum

    OpenAIRE

    Ronaldo M. Melo; Maria de F. C. Barros; Paulo M. dos Santos; Mário M. Rolim

    2008-01-01

    Com o objetivo de quantificar os parâmetros que determinam a efetividade do gesso na recuperação de solos salino-sódicos do perímetro irrigado de Custódia, localizado em Pernambuco, visando ao aumento das áreas disponíveis para a agricultura irrigada um experimento foi realizado usando-se colunas de solo instaladas no laboratório de Mecânica do Solo e Aproveitamento de Resíduos da Universidade Federal Rural de Pernambuco. Os tratamentos foram dispostos em delineamento em blocos casualizados c...

  7. 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.

  8. 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...

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

    Directory of Open Access Journals (Sweden)

    Schneider-Binder Erika

    2014-10-01

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

  10. 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...

  11. 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...

  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 polygons of constant recharge values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace...

  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. 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)

  16. 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...

  17. 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...

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

    OpenAIRE

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

    2015-01-01

    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 cha...

  19. 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...

  20. 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...

  1. Vulnerability and Pollution Risks in the Alluvial Aquifer of Tebessa-Morsott

    OpenAIRE

    S. Kachi; N. Kherici; N. Kachi

    2007-01-01

    We studied the vulnerability and risks of pollution of the alluvial aquifer of Tebessa-Morsott that ranks amongst the major groundwater reservoirs of the region. The method used to asses groundwater vulnerability was the DRASTIC method, based on seven parameters that affect and control the groundwater flow: Depth to groundwater, Impact of the unsaturated zone, net recharge, aquifer media, hydraulic conductivity, soil media, topography. These parameters were obtained from data field, synthetic...

  2. Entrainment of riparian gravel and cobbles in an alluvial reach of a regulated canyon river

    Science.gov (United States)

    Elliotp, J.G.; Hammack, L.A.

    2000-01-01

    Many canyon rivers have channels and riparian zones composed of alluvial materials and these reaches, dominated by fluvial processes, are sensitive to alterations in streamflow regime. Prior to reservoir construction in the mid-1960s, banks and bars in alluvial reaches of the Gunnison River in the Black Canyon National Monument, Colorado, USA, periodically were reworked and cleared of riparian vegetation by mainstem floods. Recent interest in maintaining near-natural conditions in the Black Canyon using reservoir releases has created a need to estimate sediment-entraining discharges for a variety of geomorphic surfaces composed of sediment ranging in size from gravel to small boulders. Sediment entrainment potential was studied at eight cross-sections in an alluvial reach of the Gunnison River in the Black Canyon in 1994 and 1995. A one-dimensional water-surface profile model was used to estimate water-surface elevations, flow depths, and hydraulic conditions on selected alluvial surfaces for discharges ranging from 57 to 570 m3/s. Onsite observations before and after a flood of 270 m3/s confirmed sediment entrainment on several surfaces inundated by the flood. Selective entrainment of all but the largest particle sizes on the surface occurred at some locations. Physical evidence of sediment entrainment, or absence of sediment entrainment, on inundated surfaces generally was consistent with critical shear stresses estimated with a dimensionless critical shear stress of 0.030. Sediment-entrainment potential over a range of discharges was summarized by the ratio of the local boundary shear stress to the critical shear stress for d50, given hydraulic geometry and sediment-size characteristics. Differing entrainment potential for similar geomorphic surfaces indicates that estimation of minimum streamflow requirements based on sediment mobility is site-specific and that there is no unique streamflow that will initiate movement of d50 at every geomorphically similar

  3. Middle-Holocene alluvial forests and associated fluvial environments: a multi-proxy reconstruction from the lower Scheldt, N Belgium

    OpenAIRE

    Deforce, Koen; Storme, Annelies; Bastiaens, Jan; Debruyne, Sofie; Denys, Luc; Ervynck, Anton; Meylemans, Erwin; Stieperaere, Herman; Neer, Wim Van; Crombé, Philippe

    2014-01-01

    Analyses of pollen, plant macrofossils (seeds, fruits, wood and mosses), molluscs, diatoms and vertebrate (mainly fish) remains allowed a detailed reconstruction of a middle-Holocene alluvial forest and its associated hydrological conditions. The use of multiple proxies resulted in a taxonomically more detailed and environmentally more comprehensive understanding of terrestrial as well as aquatic habitats. The results demonstrate possible biases in palaeoecological reconstructions of alluvial...

  4. Sources of dissolved ammonia and iron in Borovnica alluvial fan groundwater

    Directory of Open Access Journals (Sweden)

    Janko Urbanc

    2014-07-01

    Full Text Available The article deals with chemical and isotopic properties of Borovnica alluvial fan groundwater. Increased concentrations of ammonium and iron were detected in well VB-3 of the Borovnica alluvial fan pumping station. On the basis of analyses it was found out that increased concentrations of both elements are linked to the hydrogeological conditions in the aquifer area. In the upper part of the Borovnica alluvial fan aquifer, layers of clay prevent the access of oxygen to groundwater. This fact, together with the presence of organic matter in the aquifer, creates reduction conditions causing the mobility of iron and manganese in groundwater and the transformation of nitrogen from nitrate into ammonium form. Water from the lower aquifer contains more dissolved oxygen, and on the basis of tritium presence it can be concluded that the water is old up to 50 years. Wells VB-5 and VB-6 capture water from the lower pleistocene aquifer, while well VB-3 recharges also with water from the upper holocene aquifer.

  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. 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.

  7. 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

    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

  8. 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

  9. 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

  10. Saline water irrigation of quinoa and chickpea

    DEFF Research Database (Denmark)

    Hirich, A.; Jelloul, A.; Choukr-Allah, R.;

    2014-01-01

    A pot experiment was conducted in the south of Morocco to evaluate the response of chickpea and quinoa to different irrigation water salinity treatments (1, 4, 7 and 10 dS m-1 for chickpea and 1, 10, 20 and 30 dS m-1 for quinoa). Increasing salinity affected significantly (P < 0.05) seedling rate...... and height and caused delay and reduction in seed emergence, quinoa was shown to be more resistant than chickpea. Dry biomass, seed yield, harvest index and crop water productivity were affected significantly (P < 0.05) by salinity where increasing salinity level led to decrease in dry biomass, root...... volume and seed yield for both quinoa and chickpea while increasing salinity resulted in increase - in the case of quinoa - and decrease - in the case of chickpea - in harvest index and crop water productivity. Na+ and Na+/K+ ratio increased with increasing irrigation water salinity, while K+ content...

  11. 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

  12. A new method of combined techniques for characterization and monitoring of seawater interface in an alluvial aquifer

    Science.gov (United States)

    Folch, Albert; del Val, Laura; Luquot, Linda; Martínez, Laura; Bellmunt, Fabian; Le Lay, Hugo; Rodellas, Valentí; Ferrer, Núria; Fernández, Sheila; Ledo, Juanjo; Pezard, Philippe; Bour, Olivier; Queralt, Pilar; Marcuello, Alex; García-Orellana, Jordi; Saaltink, Maarten; Vázquez-Suñé, Enric; Carrera, Jesús

    2016-04-01

    Understand the dynamics of the fresh-salt water interface in aquifers is a key issue to comprehend mixing process and to quantity the discharge of nutrients in to coastal areas. In order to go beyond the current knowledge in this issue an experimental site has been set up at the alluvial aquifer Riera Argentona (Barcelona - Spain). The site comprises 16 shallow piezometers installed between 30 and 90 m from the seashore, with depths ranging between 15 and 25 meters. The seawater interface is being monitored using several techniques, the combination of which will help us to understand the spatial and temporal behaviour of the mixing zone and the geochemical processes occurring there. Specially the deepest piezometers are equipped with electrodes in order to perform cross-hole electrical resistivity tomography (CHERT). In addition, all piezometers are also equipped with Fiber Optic cable to perform distributed temperature measurements. Two single steel armoured fibre optic cable lines of around 600m length were installed in all boreholes. The objective is to use the cable both as passive and active temperature sensor. The first is being done for the continuous monitoring of temperature whereas; the second provides a higher temperature resolution used to monitor field experiments. Periodic CHERT measurements are carried out between the piezometer equipped with electrodes, resulting in parallel and perpendicular vertical cross sections of the site resistivity. The position of the fresh-salt water interface can be identified due to the resistivity contrast between the saline and fresh water. Preliminary results of periodic distributed temperature measurements will be also be used to monitor the position of the mixing zone thanks to the contrast and seasonal temperature changes. Periodic down-hole EC profiles will be used to validate the method. Acknowledgements This work was funded by the projects CGL2013-48869-C2-1 y CGL2013-48869-C2-2-R of the Spanish Government. We

  13. A global algorithm for estimating Absolute Salinity

    Directory of Open Access Journals (Sweden)

    T. J. McDougall

    2012-12-01

    Full Text Available The International Thermodynamic Equation of Seawater – 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density than does Practical Salinity.

    When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic, Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg−1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p in the world ocean.

    To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811. In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally.

  14. Salinity gradient power: utilizing vapor pressure differences.

    Science.gov (United States)

    Olsson, M; Wick, G L; Isaacs, J D

    1979-10-26

    By utilizing the vapor pressure difference between high-salinity and lowsalinity wvater, one can obtain power from the gradients of salinity. This scheme eliminates the major problems associated with conversion methods in which membranes are used. The method we tested gave higher conversion efficiencies than membrane methods. Furthermore, hardware and techniques being developed for ocean thermal energy conversion may be applied to this approach to salinity gradient energy conversion. PMID:17809370

  15. Metrological traceability of oceanographic salinity measurement results

    Directory of Open Access Journals (Sweden)

    S. Seitz

    2011-01-01

    Full Text Available Consistency of observed oceanographic salinity data is discussed with respect to contemporary metrological concepts. The claimed small uncertainty of salinity measurement results traceable to the conductivity ratio of a certified IAPSO Standard Seawater reference is not metrologically justified if results are compared on climatic time scales. This applies in particular to Practical Salinity SP, Reference Salinity SR, and the latest estimates of Absolute Salinity using the TEOS-10 formalism. On climate time scales an additional contribution to the uncertainty that is related to unknown property changes of the reference material must be accounted for. Moreover, when any of these measured or calculated quantity values is used to estimate Absolute Salinity of a seawater sample under investigation, another uncertainty contribution is required to quantify the accuracy of the equations relating the actually measured quantity to the Absolute Salinity. Without accounting for these additional uncertainties, such results cannot be used to estimate Absolute Salinity with respect to the International System of Units (SI, i.e. to the unit chosen for the mass fraction of dissolved material in the sample, which is "g kg−1". From a metrological point of view, such deficiencies in the calculations involving other quantities will produce SI-incompatible results. We outline how these problems can be overcome by linking salinity to primary SI measurement standards.

  16. Metrological traceability of oceanographic salinity measurement results

    Directory of Open Access Journals (Sweden)

    S. Seitz

    2010-07-01

    Full Text Available Consistency of observed oceanographic salinity data is discussed with respect to contemporary metrological concepts. The claimed small uncertainty of salinity measurement results traceable to the conductivity ratio of a certified IAPSO Standard Seawater reference is not metrologically justified if results are compared on climatic time scales. This applies in particular to Practical Salinity SP, Reference Salinity SR, and the latest estimates of Absolute Salinity using the TEOS-10 formalism. In climate time scales an additional contribution to the uncertainty that is related to unknown property changes of the reference material must be accounted for. Moreover, when any of these measured or calculated quantity values is used to estimate Absolute Salinity of a seawater sample under investigation, another uncertainty contribution is required to quantify the accuracy of the equations relating the actually measured quantity to the Absolute Salinity. Without accounting for these additional uncertainties, such results cannot be used to estimate Absolute Salinity with respect to the International System of Units (SI, i.e. to the unit chosen for the mass fraction of dissolved material in the sample, which is "g/kg". From a metrological point of view, such deficiencies in the calculations involving other quantities will produce SI-incompatible results. We outline how these problems can be overcome by linking salinity to primary SI measurement standards.

  17. Soil Salinity Mapping Using Multitemporal Landsat Data

    Science.gov (United States)

    Azabdaftari, A.; Sunar, F.

    2016-06-01

    Soil salinity is one of the most important problems affecting many areas of the world. Saline soils present in agricultural areas reduce the annual yields of most crops. This research deals with the soil salinity mapping of Seyhan plate of Adana district in Turkey from the years 2009 to 2010, using remote sensing technology. In the analysis, multitemporal data acquired from LANDSAT 7-ETM+ satellite in four different dates (19 April 2009, 12 October 2009, 21 March 2010, 31 October 2010) are used. As a first step, preprocessing of Landsat images is applied. Several salinity indices such as NDSI (Normalized Difference Salinity Index), BI (Brightness Index) and SI (Salinity Index) are used besides some vegetation indices such as NDVI (Normalized Difference Vegetation Index), RVI (Ratio Vegetation Index), SAVI (Soil Adjusted Vegetation Index) and EVI (Enhamced Vegetation Index) for the soil salinity mapping of the study area. The field's electrical conductivity (EC) measurements done in 2009 and 2010, are used as a ground truth data for the correlation analysis with the original band values and different index image bands values. In the correlation analysis, two regression models, the simple linear regression (SLR) and multiple linear regression (MLR) are considered. According to the highest correlation obtained, the 21st March, 2010 dataset is chosen for production of the soil salinity map in the area. Finally, the efficiency of the remote sensing technology in the soil salinity mapping is outlined.

  18. Efeitos da adição de montmorilonita sódica na dieta sobre o perfil bioquímico de frangos de corte intoxicados com aflatoxina The effects of the addition of sodic montmorilonite on the feeding diet on the biochemical profile of broiler chicken intoxicated by aflatoxin

    Directory of Open Access Journals (Sweden)

    Patricia Neves Batina

    2005-08-01

    Full Text Available Este estudo teve como objetivo avaliar os valores bioquímicos e atividade enzimática hepática e renal em frangos de corte submetidos à intoxicação experimental com aflatoxina B1 com e sem a adição de montmorilonita sódica na dieta. Foram utilizados 528 frangos de corte, da linhagem Cobb, subtimetidos a seis tratamentos entre 1° ao 42° dia de vida: (T1 Controle: dieta normal; (T2 dieta com 5 ppm de aflatoxina; (T3 dieta com 0,25% montmorilonita sódica; (T4 dieta com 5ppm de aflatoxina + 0,25% montmorilonita sódica; (T5 dieta com 0,5% montmorilonita sódica; (T6 dieta com 5ppm de aflatoxina + 0,5% montmorilonita sódica. O tratamento (T2 com aflatoxina demonstrou significante (PThe aim of this research was to evaluate the hepatic biochemical profile and the renal enzymatic activity of broiler chicken experimentally intoxicated with aflatoxin and supplemented with sodic montmorilonite on the diet. 528 Cobb’s broiler chickens were used divided in 6 treatments (from 1st to the 42th day of life as described: (T1 control: normal diet; (T2 diet with 5ppm of aflatoxin; (T3 diet with 0.25% sodic montmorilonite; (T4 diet with 5 ppm of aflatoxin + 0.25% sodic montmorilonite; (T5 diet with 0.5% sodic montmorilonite; (T6 diet with 5 ppm of aflatoxin + 0.5% sodic montmorilonite. The treatment T2 showed significantly decreased levels of uric acid, albumin, cholesterol, creatinine, triglycerides, globulins and total serum proteins and an increase of serum alanine aminotransferase (ALT activity. Aspartate aminotransferase (AST did not showed important differences among treatments. In treatments T3 and T5, there were no variations on the biochemical values, when compared to treatment T1. Addition of 0.5% of montmorilonite in the diet (T6, presented better results on the increase of the adsorption of aflatoxin when compared to 0.25% sodic montmorilonite (T4. Clearly, the results showed that high levels of aflatoxin in the diet (5ppm causes important

  19. Spatial variability of soil apparent electrical conductivity(ECa) and the water table depth in an alluvial valley under different uses.

    Science.gov (United States)

    Siqueira, G. M.; Fontes Júnior, R. V. P.; Montenegro, A. A. A.; Barros, Y. L.; Silva, E. F. F.

    2012-04-01

    The apparent soil electrical conductivity (ECa), measured by contact or by electromagnetic induction (EMI), has been widely used as a variable that is correlated with physical and chemical soil properties. Therefore this property is used as a parameter in precision agriculture, to enable assessment of soil spatial variability and defining management units, allowing obtaining information about other soil properties like texture, salinity, water content, among others. These conditions are adequate to study spatial variability of data with the help of geostatistics, which models the spatial variability of soil properties, allowing the construction of spatial variability maps unbiased and with minimum variance. Thus, the goal this work was assess the variability special of electrical conductivity apparent soil (ECa) and the water table level in an alluvial valley in the brazilian semi-arid adopting different uses. The studied alluvial valley is located in Pesqueira (Pernambuco State, Brazil) and has 421.0 hectares. The main soil types occurring in the valley are: Fluvic Neosols , litholic Neossols and regolithic Neosols . Climate according to Koppen's classification is BSsh type, with total annual rainfall average of 730mm. The attributes evaluated in this study were sampled at 88 piezometric wells. The apparent soil electrical conductivity (ECa) was measured by electromagnetic induction with the EM38 device (Geonics Ltd) in vertical dipole (effective depth 1.5m). The ground water table was determined in piezometric wells with the aid of a measuring tape. Data were analyzed by using descriptive statistics and geostatistical tools. The land use map was constructed using field verification and spatialized by means of GIS. The attributes analyzed showed Normal frequency distribution. ECa readings ranged between 8 and 79 mS m-1. The major differences between the ECa values are due to the variation of water content in soil and distance from the water table at the soil

  20. 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.

  1. 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.

    2014-11-01

    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 (50 km2) 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 δ18OH2O and δ2HH2O 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 52 mg/L, and the nitrate concentration of infiltrating river at approximately 6 mg/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.

  2. Unraveling fan-climate relationships: Milankovitch cyclicity in a Miocene alluvial fan (Teruel Basin, Spain)

    Science.gov (United States)

    Ventra, D.; Abels, H. A.; Hilgen, F. J.; de Boer, P. L.

    2009-04-01

    The role of climate change in alluvial fan sedimentation is often evident in geomorphological studies dealing with Quaternary successions, but remains hard to assess in the pre-Quaternary stratigraphic record, for which an additional obstacle is represented by detailed chronologies difficult to established within coarse clastic systems. The Teruel Basin (eastern Spain) is an extensional trough whose main tectonic activity spanned from late Oligocene to Pliocene times. Permanent internal drainage and a Mediterranean semi-arid climate made the basin and its sedimentary signatures highly sensitive to climate fluctuations, especially in terms of hydrological balance. Recent studies have proved orbital control on the development of facies sequences from low-energy, basinal settings in Teruel. In particular, high-resolution chronological and paleoclimatic information has been derived by orbital tuning of mudflat to ephemeral lake deposits in the Prado area (Villastar), linking basic facies rhythms to alternating, relatively humid/arid phases paced mainly by climatic precession. Clastic lobes from a coeval alluvial fan distally interfinger with this reference section. Stratigraphic relationships show how fan sedimentation patterns were also influenced by climate cyclicity. Highest volumes of debris transfer towards the distal mudflat repeatedly coincide with relatively humid periods. Furthermore, distal to medial fan outcrops feature prominent rhythms of distinct, alternating coarse and fine clastic packages. Such a highly organized architecture, unusual in alluvial fan successions, points to the influence of a rhythmic forcing mechanism which might have been climate variability, as evidenced by the adjacent reference section. Rather than on processes of sediment transport basinwards, climate change would have acted on sediment production and availability at the source, within the fan catchment.

  3. Developing Pedotransfer Functions for Saline and Saline-Alkali Soils

    Science.gov (United States)

    Ramezani, Meysam; Ghanbarian-Alavijeh, Behzad; Liaghat, Abdolmajid

    2010-05-01

    Soil moisture curve is one of the soil hydraulic properities which its direct measurement is time consuming and expensive. Therefore, indirect methods such as developing pedotransfer functions have been used to predict this characteristic from soil readily available or easily measurable data. In this study, multiple linear regression method was used to develop point pedotransfer functions (PTFs) for saline and saline-alkali soils of Iran. For this purpose, 68 soil samples which their EC values were greater than 4 ds/m, and more than half of them had ESP values greater than 15% were selected. Using Jackknife method, the random splitting of data into the development and validation subsets was repeated 10 times. A ratio of 3:1 was used to split data into development and validation sets in each replication. In the SPSS software, parameters such as geometric standard deviation (δg), geometric mean diameter (dg), sodium adsorption ratio (SAR), electrical conductivity (EC), carbonate calcium (CaCO3), bulk density (BD), organic matter (OM), and clay and silt content were applied as the independent variables, and volumetric water content was determined at matric potentials of -10, -33, -100 , -300, -500, -1000, -1500 kPa. The derived PTFs were compared with the H3 model of Rosetta software for 10 splits of validation data set. Comparison of the mean RMSE and R2 values showed that the developed PTFs resulted in more accurate estimation than the Rosetta software at matric potentials of -100 , -300, -500, -1000, -1500 kPa. Whereas, Rosetta model resulted in slightly better estimation than derived PTFs at matric potentials of -10, -33 kPa. For the PTFs developed in this study, the RMSE and R2 values ranged from 0.12 to 0.35 (cm3.cm-3) and 0.64 to 0.83, respectively. While for the Rosetta model, RMSE and R2 values ranged from 0.22 to 0.33 (cm3.cm-3) and 0.37 to 0.74, respectively.

  4. Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

    International Nuclear Information System (INIS)

    The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC50). This LC50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC50. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC50 values. In contrast, LC50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

  5. 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...

  6. Alluvial fan response to climatic change: Insights from numerical modeling (Invited)

    Science.gov (United States)

    Pelletier, J. D.

    2009-12-01

    Alluvial fans in the western U.S. exhibit a regionally correlative sequence of Plio-Quaternary deposits. Cosmogenic and U-series dating has greatly improved the age control on these deposits and their associated terraces and generally strengthened the case for aggradation during humid-to-arid transitions. Still, the linkages between climate change, upland basin response, and alluvial fan response are not well constrained. Fans may fill and cut as a result of autogenetic processes/internal adjustments, changes in regional temperature (which controls snowmelt-induced flooding), changes in the frequency-size distribution of rainfall events, and/or changes in upslope vegetation. Here I describe the results of a numerical modeling study designed to better constrain the relationships between different end-member forcing mechanisms and the geologic record of alluvial fan deposits and terraces. The model solves the evolution of the fan topography using Exner's equation (conservation of mass) coupled with a nonlinear, threshold-controlled transport relation for sand and gravel. Bank retreat is modeled using an advection equation with a rate proportional to bank shear stress. I begin by considering the building of a fan under conditions of constant water and sediment supply. This simple system exhibits all of the complexity of fans developed under experimental conditions, and it provides insights into the mechanisms that control avulsions and it provides a baseline estimate for the within-fan relief that can result from autogenetic processes. Relationships between the magnitude and period of variations in the sediment-to-water ratio and the geomorphic response of fans are then discussed. I also consider the response of a coupled drainage basin-fan system to changes in climate, including the hydrologic and vegetation response of upland hillslopes. Fans can aggrade or incise in response to the same climatic event depending on the relief of the upstream drainage basin, which

  7. [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

  8. Minimal groundwater leakage restricts salinity in a hydrologically terminal basin of northwest Australia

    Science.gov (United States)

    Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline

    2016-04-01

    The Fortescue Marsh (FM) is one of the largest wetlands of arid northwest Australia (~1200 km2) and is thought to act as a terminal basin for the Upper Fortescue River catchment. Unlike the playa lake systems that predominate in most arid regions, where salinity is driven by inflow and evaporation of groundwater, the hydrological regime of the FM is driven by inundation from irregular cyclonic events [1]. Surface water of the FM is fresh to brackish and the salinity of the deepest groundwater (80 m b.g.l.) does not exceed 160 g/L; salt efflorescences are rarely present on the surface [2]. In this study, we tested the hypothesis that persistent but low rates of groundwater outflow have restricted the accumulation of salt in the FM over time. Using hydrological, hydrochemical data and dimensionless time evaporation modelling along with the water and salt budget, we calculated the time and the annual groundwater discharge volume that would be required to achieve and maintain the range of salinity levels observed in the Marsh. Groundwater outflow from alluvial and colluvial aquifers to the Lower Fortescue catchment is limited by an extremely low hydraulic gradient of 0.001 and is restricted to a relatively small 'alluvial window' of 0.35 km2 because of the elevation of the basement bedrock at the Marsh outflow. We show that if the Marsh was 100% "leakage free" i.e., a true terminal basin for the Upper Fortescue Catchment, the basin water would have achieved salt saturation after ~45 ka. This is not the case and only a very small outflow of saline groundwater of GL/yr (<0.03% of the FM water volume) is needed to maintain the current salinity conditions. The minimum time required to develop the current hydrochemical composition of the water in the Marsh and the steady-state conditions for salt concentration is between 58 and 164 ka. This is a minimum age of the Marsh but it can be much older as nearly steady-state conditions could be maintained infinitely. Our approach

  9. Susceptibility to saline contamination of coastal confined aquifer of the Uraba banana axis with hydrogeochemical and isotopic techniques

    International Nuclear Information System (INIS)

    The project has covered an area of study of 8916 km2 is located in the Northwestern part of the Department of Antioquia, Colombia. Interest area is geologically constituted by tertiary sedimentary rocks (T1 and T2) and alluvial deposits (Quaternary). Hydrogeological units, potentially better use of groundwater, have been established for the unit T2 (confined aquifer) and quaternary deposits.) The area has been of 2600 mm/year to 3600 mm/year of average rainfall. The susceptibility to saline contamination has been determined of coastal aquifer of the Uraba banana axis. Hydrochemical and geological information, geophysics, hydraulic and hydrochemical is used improving existing conceptual hydrogeological model. A hydrochemical characterization has been performed to evaluate the processes of salinity in the confined aquifer. The integration of geological information, geophysical and hydrogeological has been methodology used to validate the hydraulic characteristics of the aquifer, its geometry and operation, updating the conceptual hydrogeological model. The use of complementary tools been able to determine and identify processes that may affect natural physico-chemical characteristics of groundwater. The results have showed that salinization processes present in the coastal aquifer of Uraba Banana Axis could be linked to water-rock interaction, to mixtures with water have become saline as a result of transgression - regression processes in the former study. The hydrogeochemical techniques have become a complementary tool to the hydrogeology allowing respond the questions were presented in complex systems, such as the case of coastal aquifers, where sanitation is usually associated with saline intrusion processes and can also be obeying the conjunction with other hydroclimatological and hydrodynamic aspects. (author)

  10. Therapeutic Efficacy of Saline and Glucose Saline against Dermally applied Sulphur Mustard Intoxication in Mice

    Directory of Open Access Journals (Sweden)

    K. Sugendran

    1994-01-01

    Full Text Available A single dose of saline or glucose-saline (5 mg glucose/kg offered similar protection to mice against sulphur mustard intoxication, the extent of survival being 83 per cent as against 33 per cent without treatment. All the animals were protected when the treatment was extended by another two consecutive days in the glucose-saline treated group. Both saline and glucose-saline treatments could ameliorate the haemoconcentration as well as normalise pO/sub 2/ and % oxygen saturation. The protection conferred is attributed to the probable replenishment of fluid loss.

  11. Reconstructing Past Ocean Salinity ((delta)18Owater)

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T P; Pak, D K

    2005-11-23

    Temperature and salinity are two of the key properties of ocean water masses. The distribution of these two independent but related characteristics reflects the interplay of incoming solar radiation (insolation) and the uneven distribution of heat loss and gain by the ocean, with that of precipitation, evaporation, and the freezing and melting of ice. Temperature and salinity to a large extent, determine the density of a parcel of water. Small differences in temperature and salinity can increase or decrease the density of a water parcel, which can lead to convection. Once removed from the surface of the ocean where 'local' changes in temperature and salinity can occur, the water parcel retains its distinct relationship between (potential) temperature and salinity. We can take advantage of this 'conservative' behavior where changes only occur as a result of mixing processes, to track the movement of water in the deep ocean (Figure 1). The distribution of density in the ocean is directly related to horizontal pressure gradients and thus (geostrophic) ocean currents. During the Quaternary when we have had systematic growth and decay of large land based ice sheets, salinity has had to change. A quick scaling argument following that of Broecker and Peng [1982] is: the modern ocean has a mean salinity of 34.7 psu and is on average 3500m deep. During glacial maxima sea level was on the order of {approx}120m lower than present. Simply scaling the loss of freshwater (3-4%) requires an average increase in salinity a similar percentage or to {approx}35.9psu. Because much of the deep ocean is of similar temperature, small changes in salinity have a large impact on density, yielding a potentially different distribution of water masses and control of the density driven (thermohaline) ocean circulation. It is partly for this reason that reconstructions of past salinity are of interest to paleoceanographers.

  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. 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.

  14. Influence of Climatic Changes and Human Activities on the Salinization Process of Coastal Aquifer Systems

    Directory of Open Access Journals (Sweden)

    Dimitra Rapti-Caputo

    2010-10-01

    Full Text Available In the present research, two arid coastal zones of the Mediterranean region (mean annual precipitation about 440 mm/a, have been investigated for evaluating the qualitative and quantitative impact of both human activities and climatic changes on the groundwater resources and the hydrological cycle in general. In particular, the hydrographic network of the Akrotiri (Cyprus coastal aquifer system is strongly controlled by engineering handicrafts that have induced a quality worsening of the groundwater resources. Due to over-pumping in the central sector of the area, a lowering of the piezometric level of about 15 m has been observed. As a consequence, a salinization process has occurred in the coastal sector with a mean annual salinization velocity of the salty water front varying between 47 and 97 cm/a (period 1964-1996. Due to the high salinity values, the water is at present unsuitable for irrigation use. The second case study is represented by the alluvial plain of Licata (southern Sicily, Italy, where the evolution of the Salso River (in Italian the name means ’Salty River’ and the coastal dynamics, characterised by repeated marine transgressions and regressions, qualitatively and quantitatively influenced the underground water resources. Also the anthropogenic activities played a crucial role, especially the farming activity as it is largely documented by the occurrence of numerous greenhouses covering most of the plain. The water depth of the unconfined, mainly sandy, aquifer developed in the Quaternary deposits is between 0.3 m and locally 5 m from the surface, while the principal alimentation occurs via infiltration from precipitations and lateral outflow from the Salso River.

  15. 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

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

    Science.gov (United States)

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

    2016-07-01

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

  17. 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

  18. 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.

  19. 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

  20. 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.

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

    International Nuclear Information System (INIS)

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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-05-01

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

  8. Investigation of the origin of marking by uranium in the alluvial table of the Tricastin plain

    International Nuclear Information System (INIS)

    This document reports an investigation which has been commissioned after a previous one in 2007 and also after an incident which occurred in the SOCATRI factory on the Tricastin nuclear site in July 2008. This incident entailed the implementation of a survey plan of measurements of uranium in the water table around the site, and of another investigation on the origin of high uranium concentrations observed in this water table. This second investigation is the topic of this report. Results are presented on the alluvial table morphology and behaviour (hydrology, hydrogeology, relationship between table and rivers), and a cartography of its uranium content is proposed. Then, three hypotheses for these high concentrations have been tested: an origin related to the local geology (geological analysis of the site), an anthropic origin other than that related to the nuclear site (analysis of other industrial sites), and an origin related to the nuclear site (discussion of past and present activities, previous and present situation in terms of presence of uranium, analysis and modelling of transfers in the alluvial table)

  9. Differential Expression of Salinity Resistance Gene on Cotton

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Salinity resistance and differential gene expression associated with salinity in cotton germplasm were studied,because of the large scale area of salinity in China,and its significant negative effects on

  10. 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.

  11. Koroška Bela alluvial fan – The result of the catastrophic slope events; (Karavanke Mountains, NW Slovenia

    Directory of Open Access Journals (Sweden)

    Jernej Jež

    2008-12-01

    Full Text Available The Koroška Bela alluvial fan deposits were investigated to determine the genesis of the fan and the source area of sediments. The alluvial fan is composed of a sequence of diamicton layers, and related subaeric sediments that were deposited by multiple mass flow events, in some cases certainly by debris flows. The predominant sources ofsediments are tectonically deformed clastic and partly carbonate Carbonifferous and Permian rocks. In diamictons also pebbles of other rocks from the hinterland are present. These were eroded from the channel of Bela during the mass flow events. We estimate the future debris flow hazard along Bela stream as high.

  12. Crescimento inicial do cafeeiro irrigado com água salina e salinização do solo Initial growth of coffee plants irrigated with saline water and soil salinization

    Directory of Open Access Journals (Sweden)

    Vladimir B. Figueirêdo

    2006-03-01

    plants. The leaf area of plant was the variable most affected by salinity of irrigation water. By the end of the experiment, the soil was classified as saline-sodic.

  13. 松嫩平原西部盐沼的形成与演化%Study on the Formation and Changes of Saline-Alkaline Mire in Songnen Plain

    Institute of Scientific and Technical Information of China (English)

    李取生; 邓伟; 钱贞国

    2000-01-01

    摘要:本文运用环境变迁的理论和方法,较系统地分析了松嫩平原西部盐沼的形成与演变机制。本区沼泽形成的主要控制因素是古河道变迁、新构造运动、风力作用、古气候变化。沼泽残余盐碱化与晚更新世松辽大湖的消亡、河道变迁有关,现代盐碱化则主要是水利工程、植被破坏和气候变化引起的,而且呈迅速加剧的趋势。防治沼泽盐碱化的主要措施是实施水稻和芦苇开发、大规模建立蓄洪区和自然保护区。%The saline-sodic mires with areas of 578000 hrn2 in the western Songnen Plain are one kind of the importantland resources and the most prospective landscape. However, they faced to rapid development of salinisation and degrada-tion of ecological function. The study of the formation and changes processes is significant for saline- sodic mires manage-ment. In this paper the mechanism of saline- sodic mire formation and development was analyzed systematically using themethodology and theory of environmental change. The genesis of the mire here are: ①uneven subsidence of the crustmused by Neo- tectonic movement,② widespread distributed paleo- river channels and water- logged lands caused byfrequently river channel changes since Late Pleistocene, ③ wind erosion resulted in the eolian water-logged land mires,④ paleo-climate also caused the mire changes. The processes of mire salinisafion include historical relic salinisation and modem salinisation. The mechanism of his-torical relic salinisafion is the long term accumulation of salts because of the evaporation in the closed lake basins formedafter the disappearance of paleo- Songliao Big Lake, the logged lands formed by river channel changes and eolian erosion.In this area there was a lake as big as 50,000ki2 during early Pleistocene and middle Pleistocene. Since late Pleistocenethis lake disappeared and formed lot of small dosed shallow ponds or water- logged lands because of

  14. Salinity extrema in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S; Shetye, S; Gouveia, A.D.; Michael, G.S

    Levitus (1982) climatology has been used to identify four extrema, three maxima and one minimum, in the vertical salinity profiles in the Arabian Sea. Their geographical distribution, depths, theta-S characteristics, and seasonal variability...

  15. Cold saline is more effective than room temperature saline in inducing paresthesia during axillary block.

    Science.gov (United States)

    Rodríguez, J; Carceller, J; Bárcena, M; Pedraza, I; Calvo, B; Alvarez, J

    1995-08-01

    Confirmation of the perivascular position of the needle by the injection of cold saline may be helpful to the perivascular technique, since the elicitation of a paresthesia indicates the correct positioning of the needle. In this prospective, randomized study of 48 patients, we found a 100% incidence of successful block with saline at 8-11 degrees C compared to 75% in a control group with saline at room temperature. The paresthesia induced by cold saline appears to be due to thermic stimulation and not to mechanical nerve compression by the saline entering the axillary space. A more frequent rate of correct positioning of the needle was found in the group with cold saline. PMID:7618724

  16. BENEFITS OF CONTROLLING SALINE WATER IN COLORADO

    OpenAIRE

    Ellingson, Lindsey; Houk, Eric E.; Schuck, Eric C.; Frasier, W. Marshall

    2004-01-01

    The Arkansas River in Colorado is confronted with a salinity issue; the majority of this salinity problem is due to agricultural runoff caused by irrigation. Reducing applications of irrigation water through adoption of more technically efficient irrigation systems is one means of improving water quality in the Arkansas River basin. This research uses positive mathematical programming to model the cropping practices of the farms along the Arkansas River. It examines the affect of acreage and ...

  17. Salinity management in southern Italy irrigation areas

    OpenAIRE

    Massimo Monteleone

    2011-01-01

    After a synthetic review of the most worrisome pressures applied over soils and waters, general criterions and normative principles that have to lead the technical intervention on soil and water protection are accounted, both with respect to farm activity and land planning. The salinity problem is faced, then, through the analysis of the nature and origin of saline soil and of the complex quantitative relationships able to interpret the accumulation and leaching of soil salts. Having specifie...

  18. Salinity management in southern Italy irrigation areas

    Directory of Open Access Journals (Sweden)

    Massimo Monteleone

    2011-02-01

    Full Text Available After a synthetic review of the most worrisome pressures applied over soils and waters, general criterions and normative principles that have to lead the technical intervention on soil and water protection are accounted, both with respect to farm activity and land planning. The salinity problem is faced, then, through the analysis of the nature and origin of saline soil and of the complex quantitative relationships able to interpret the accumulation and leaching of soil salts. Having specified the theoretical bases of salinity, the related technical features are then considered in order to define a proper management of soil and waters. Particular relevance is assigned to the irrigation and leaching techniques as well as, more briefly, to other agronomic interventions in order to guarantee the most effective salinity control. Another relevant technical facet of salinity control, although quite often neglected or retained of secondary importance in comparison to irrigation, is the drainage and disposal of leached water. The increased sensibility on the environmental impacts that the disposal of these waters can produce has raised today the level of attention on these procedures that are disciplined by norms of law and, therefore, require appropriate techniques of intervention. Finally, after the different scale orders involved in the management of salinity are defined (from the field and farm level up to the land and basin, the fundamental elements in order to work out a risk analysis and an action program are illustrated; some indications about the most up to date salinity monitoring and mapping methods are also provided, considering their great importance to continuously check the possible broadening of salinization and to carefully maintain its control.

  19. Growth of sugar cane varieties under salinity

    OpenAIRE

    Welson Lima Simões; Marcelo Calgaro; Daniela Siqueira Coelho; Delfran Batista dos Santos; Moisés Alves de Souza

    2016-01-01

    ABSTRACT Large salty areas in the Brazilian semi-arid region have limited farming in Northeastern Brazil. One example is the sugar cane cultivation, which reinforces the need of selecting varieties that are more tolerant to salinity. The objective of this study was to evaluate the effect of salinity on growth of ten varieties of sugar cane. The experiment was conducted in a greenhouse, set in the experimental field of Embrapa Semiárido, in Petrolina, Pernambuco State. The experimental design ...

  20. MULTIVARIATE GEOSTATISTICAL METHODS FOR MAPPING SOIL SALINITY

    OpenAIRE

    BİLGİLİ, A.V.; ÇULLU, M.A.; AYDEMİR, A.; Turan, V; SÖNMEZ, O.; AYDEMİR, S.; Kaya, C.

    2012-01-01

    Degradation of the lands by salinity under arid climate and poor drainage conditions can be inevitable. In the Harran plain total salt affected areas covers 10 % of total irrigated areas which are mainly located in the low lying parts of the plain where elevation ranges from 350 to 400 m. Soil salinity shows high spatial variability which requires intensive sampling and laboratory analyses. Geostatistical techniques such as simple or ordinary kriging can be used in explaining this spatial var...

  1. Salinity management in southern Italy irrigation areas

    Directory of Open Access Journals (Sweden)

    Massimo Monteleone

    Full Text Available After a synthetic review of the most worrisome pressures applied over soils and waters, general criterions and normative principles that have to lead the technical intervention on soil and water protection are accounted, both with respect to farm activity and land planning. The salinity problem is faced, then, through the analysis of the nature and origin of saline soil and of the complex quantitative relationships able to interpret the accumulation and leaching of soil salts. Having specified the theoretical bases of salinity, the related technical features are then considered in order to define a proper management of soil and waters. Particular relevance is assigned to the irrigation and leaching techniques as well as, more briefly, to other agronomic interventions in order to guarantee the most effective salinity control. Another relevant technical facet of salinity control, although quite often neglected or retained of secondary importance in comparison to irrigation, is the drainage and disposal of leached water. The increased sensibility on the environmental impacts that the disposal of these waters can produce has raised today the level of attention on these procedures that are disciplined by norms of law and, therefore, require appropriate techniques of intervention. Finally, after the different scale orders involved in the management of salinity are defined (from the field and farm level up to the land and basin, the fundamental elements in order to work out a risk analysis and an action program are illustrated; some indications about the most up to date salinity monitoring and mapping methods are also provided, considering their great importance to continuously check the possible broadening of salinization and to carefully maintain its control.

  2. Sea Surface Salinity : Research Challenges and Opportunities

    Science.gov (United States)

    Halpern, David; Lagerloef, Gary; Font, Jordi

    2012-01-01

    Sea surface salinity (SSS) can be important in regulating sea surface temperature (SST). Two technological breakthrough satellite SSS missions, Aquarius and Soil Moisture and Ocean Salinity (SMOS), are currently producing high-quality SSS data. This paper provides an overview of the importance of SSS for weather and climate applications and describes the Aquarius and SMOS missions. The newness of adequately sampled SSS data prompted a first-time at-sea field campaign devoted to improved understanding of SSS variations.

  3. Benchmarking worldwide CO₂ saline aquifer injections

    OpenAIRE

    Hosa, Aleksandra; Esentia, Mina; Stewart, Jamie; Haszeldine, Stuart

    2010-01-01

    Carbon Capture, Transport and Storage is a very active field of research, especially for the past decade. From the UK perspective, a commercially crucial aspect is the saline aquifer research, since there are predicted to be vast storage capacities in the sedimentary formations of the North Sea. The following report reviews the ongoing work on practical injections of CO2 as research tests for storage projects and specifically focuses on industrial sized saline aquifer injections.

  4. Macquarie River Basin pilot salinity project

    OpenAIRE

    Macquarie River Food and Fibre Association (MRFFA); State Forests

    2006-01-01

    In order to lower salinity levels in Australia's Mullay-Darling watershed, a pilot study using water transpiration credits is being tried to increase forest cover. A company, State Forests, is managing 2 million hectares of public native forests along with increasing amounts of planted forests. Local irrigation farmers have entered into an agreement with State Forests to support tree planting in turn for salinity credits. The goal is large scale reforestation, 40% reforestation is the goal to...

  5. Treating nahcolite containing formations and saline zones

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J

    2013-06-11

    A method for treating a nahcolite containing subsurface formation includes removing water from a saline zone in or near the formation. The removed water is heated using a steam and electricity cogeneration facility. The heated water is provided to the nahcolite containing formation. A fluid is produced from the nahcolite containing formation. The fluid includes at least some dissolved nahcolite. At least some of the fluid is provided to the saline zone.

  6. THE EFFECT OF NORMAL SALINE AND 3.5% HYPERTONIC SALINE ON MUCOCILIARY CLEARANCE IN SINUSITIS

    Directory of Open Access Journals (Sweden)

    Mahesh

    2014-10-01

    Full Text Available Introduction: Sinusitis is usually treated with antibiotics, decongestants, mucolytics and steroids. Long term use of these drugs has many side effects. This has led to the use of other modalities of treatment such as saline nasal irrigation. Saline nasal irrigation helps in clearance of secretions, debris and crusts, thus improving the mucociliary clearance. OBJECTIVE: This randomized comparative study was undertaken to assess the ciliary function by performing saccharine test and to evaluate the effect of 3.5% hypertonic saline nasal drops against normal saline nasal drops on mucociliary transit time of saccharine. MATERIALS AND METHODS: Fifty patients diagnosed as chronic sinusitis in the age group of 18 to 45 years were randomized into two groups; Group A treated with 0.9% normal saline and Group B with 3.5% hypertonic saline for a period of 4 weeks. Mucociliary transit time was recorded by performing saccharine test before and after treatment. RESULTS: Significant improvement was seen in both the groups but when compared to normal saline, hypertonic saline significantly improved the mucociliary clearance. The mean mucociliary transit time of saccharine in Group A patients before treatment was 19.860 minutes and after treatment was 17.634 minutes (t=14.012, p=0.0001. The mean mucociliary transit time of saccharine in Group B patients before treatment was 21.881 minutes and after treatment was 16.689 minutes (t=14.662, p=0.0001. All the patients reported relief of symptoms, but relief was much earlier in Group B when compared to Group A. Mild burning sensation in the nose and throat was reported by 4% of patients in Group A and 8% in Group B. CONCLUSION: Both 0.9% normal saline and 3.5% hypertonic saline significantly improved the mucociliary clearance. Hypertonic saline is more efficacious than normal saline in the treatment of chronic sinusitis

  7. Soil and water salinization and the development of organic saline crops

    OpenAIRE

    Timmermans, B.G.H.; Hospers - Brands, Monique

    2014-01-01

    Saline water and soils present an increasing problem for agriculture. Adaptation strategies of agriculture include selection of existing crops on salt tolerance, and development of new tolerant or halophyte crops. Saline areas are often located close to sensitive nature, and at least in The Netherlands, the development of saline crops represent a challenge to sustainable and organic agriculture. We tested salt tolerance of two new plant species that have some prospects as future crops: S...

  8. Salinity Effect on Horticultural Crops: Morphological, Physiological, and Biomolecular Elements of Salinity Stress Response

    OpenAIRE

    Sanoubar, Rabab

    2014-01-01

    Among abiotic stresses, high salinity stress is the most severe environmental stress. High salinity exerts its negative impact mainly by disrupting the ionic and osmotic equilibrium of the cell. In saline soils, high levels of sodium ions lead to plant growth inhibition and even death. Salt tolerance in plants is a multifarious phenomenon involving a variety of changes at molecular, organelle, cellular, tissue as well as whole plant level. In addition, salt tolerant plants show a range of ada...

  9. Response of Durum Wheat Seedlings to Salinity

    Directory of Open Access Journals (Sweden)

    Mehmet YILDIRIM

    2015-04-01

    Full Text Available Salinity is an important source of abiotic stress, limiting crop performance in most arid and semi-arid areas of the world. This research was conducted to determine the effects of salinity on physiological parameters of durum wheat (Triticum durum Desf. genotypes. The research was conducted in the tissue culture laboratory at the Agriculture Faculty of Dicle University. The study consisted of one durum wheat commercial cultivar, five local cultivars and four advanced genotypes. There were three replications in a split-plot experimental design. Genotypes were germinated in four NaCl concentrations (0, 50, 100, 150 mM in plastic boxes. There were statistically assured significant differences among the genotypes for all salt concentrations and all observed parameters (coleoptile length, seedling length, root length, seedling fresh weight, root fresh weight, seedling dry weight, root dry weight, germination rate and seedling vigor. There was significant decrease in all examined parameters depending on the increase of salt concentration. The ‘Sorgul’ genotype was most tolerant to salinity, in terms of root length and root dry weight, whereas ‘Altintoprak 98’ was most tolerant as measured by the impact of salinity on coleoptile length, seedling fresh weight, germination rate and seedling vigour. The ‘Beyaziye’ genotype was the most sensitive to salinity-induced stress. The results from this study demonstrated differences among durum wheat genotypes for seedling parameters measured in the presence of salinity stress.

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. Concentration and Grist size spectrum of Airborne dust during operation of earth moving machineries of Alluvial soil

    Directory of Open Access Journals (Sweden)

    S. C. Ganguli

    1963-01-01

    Full Text Available Concentration and grist size spectrum of airborne dust generated by heavy earth moving machinery while operating on alluvial soil on the Indogangetic plain at Roorkee (29.52DegreeN, 77.53DegreeEN has been determined.

  14. 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.

  15. 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

  16. Cosmogenic helium and volatile-rich fluid in Sierra Leone alluvial diamonds

    Science.gov (United States)

    Mcconville, P.; Reynolds, J. H.

    1989-01-01

    Noble gas measurements were carried out on two identical splits of a finely powdered harshly acid-washed sample derived from fragments of a single alluvial diamond from Sierra Leone, with essentially identical results obtained for both splits. Isotopic ratios for Ar, Kr, and Xe were found to be atmospheric. Their elemental abundances were high relative to published data, owing to the effect of shock implantation in the crushing step, as was verified in a supplementary experiment. No Ne was detected above the blank level. The He-3 was exceptionally abundant, while He-4 was exceptionally depleted, possibly due to the acid wash. The He-3/He-4 ratio was anomalously high at an R/Ra value of 246 + or - 16. The results support the hypothesis that the He-3 excess in diamonds is cosmogenic.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    SUCIATMIH

    2006-10-01

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

  19. 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.

  20. 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

  1. Planktonic Euglenophytes of alluvial pools in Litovelske Pomoravi and Poodri Protected Landscape Areas (Czech Republic)

    International Nuclear Information System (INIS)

    The study of phytoplankton focused on Euglenophytes was carried out in a floodplain areas of Morava river in Litovelske Pomoravi Protected Landscape Area and Odra river in Poodri Protected Landscape Area. The alluvial pools with different degree of organic pollution was sampled in the years 1999-2002. Altogether, about 60 species of Euglenophytes were found during this study. The greatest diversity was observed within the genera Euglena and Trachelomonas. The mass occurrence of the genus Euglena was observed frequently creating water blooms (especially E. agilis). Other species, sometimes observed in high abundance, were E. acus, E. spirogyra, E. tripteris, E. hemichromata and at some eutrophic pools also E. viridis. Although, the abundance of the genus Trachelomonas was lower than previous one, its species diversity was high. The most frequent species were found T. volvocina, T. volvocinopsis, T. hispida, T. curta and T. oblonga. Among another frequent genera belonged: Phacus, Lepocinclis, Strombomonas and Astasia. The most frequent species of Phacus were found P. orbicularis, P. pleuronectes, P. longicauda and P. caudatus. Genus Lepocinclis was frequent only in a few pools in Poodri and it was rare in Litovelske Pomoravi. The seasonal dynamics of Euglenophytes in plankton of alluvial pools showed two peaks of high abundance. The first peak occurred from May to June, the second one occurred from September to October. The positive correlation between the quantity of Euglenophytes and ammonium ions concentration was observed (NH4+: 1.5-4.0 mg.l-1). Euglenophytes were observed in very low quantity (or were not observed) during the winter period and practically absent under the ice cover. (authors)

  2. Benzene dispersion and natural attenuation in an alluvial aquifer with strong interactions with surface water

    Science.gov (United States)

    Batlle-Aguilar, Jordi; Brouyère, Serge; Dassargues, Alain; Morasch, Barbara; Hunkeler, Daniel; Höhener, Patrick; Diels, Ludo; Vanbroekhoven, Karolien; Seuntjens, Piet; Halen, Henri

    2009-05-01

    SummaryField and laboratory investigations have been conducted at a former coke plant, in order to assess pollutant attenuation in a contaminated alluvial aquifer, discharging to an adjacent river. Various organic (BTEX, PAHs, mineral oils) and inorganic (As, Zn, Cd) compounds were found in the aquifer in concentrations exceeding regulatory values. Due to redox conditions of the aquifer, heavy metals were almost immobile, thus not posing a major risk of dispersion off-site the brownfield. Field and laboratory investigations demonstrated that benzene, among organic pollutants, presented the major worry for off-site dispersion, mainly due to its mobility and high concentration, i.e. up to 750 mg L -1 in the source zone. However, benzene could never be detected near the river which is about 160 m downgradient the main source. Redox conditions together with benzene concentrations determined in the aquifer have suggested that degradation mainly occurred within 100 m distance from the contaminant source under anoxic conditions, and most probably with sulphate as main oxidant. A numerical groundwater flow and transport model, calibrated under transient conditions, was used to simulate benzene attenuation in the alluvial aquifer towards the Meuse River. The mean benzene degradation rate used in the model was quantified in situ along the groundwater flow path using compound-specific carbon isotope analysis (CSIA). The results of the solute transport simulations confirmed that benzene concentrations decreased almost five orders of magnitude 70 m downgradient the source. Simulated concentrations have been found to be below the detection limit in the zone adjacent to the river and consistent with the absence of benzene in downgradient piezometers located close to the river reported in groundwater sampling campaigns. In a transient model scenario including groundwater-surface water dynamics, benzene concentrations were observed to be inversely correlated to the river water

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

    International Nuclear Information System (INIS)

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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  9. Growth of sugar cane varieties under salinity

    Directory of Open Access Journals (Sweden)

    Welson Lima Simões

    2016-04-01

    Full Text Available ABSTRACT Large salty areas in the Brazilian semi-arid region have limited farming in Northeastern Brazil. One example is the sugar cane cultivation, which reinforces the need of selecting varieties that are more tolerant to salinity. The objective of this study was to evaluate the effect of salinity on growth of ten varieties of sugar cane. The experiment was conducted in a greenhouse, set in the experimental field of Embrapa Semiárido, in Petrolina, Pernambuco State. The experimental design was randomized blocks arranged in a 6 X 10 factorial arrangement, comprised of six levels of salinity (0, 1.0, 2.0, 4.0, 6.0 and 8.0 dS m-1 and ten sugar cane varieties (VAT 90212; RB 72454; RB 867515; Q 124; RB 961003; RB 957508; SP791011; RB 835089; RB 92579 and SP 943206. Salt levels of irrigation water were obtained by adding NaCl, CaCl2.2H2O and MgSO4.7H2O to achieve an equivalent ratio among Na:Ca:Mg of 7:2:1. Sixty days later, plant height, stem diameter (base, number of leaves, stalks and sprouts, leaf area and fresh and dry mass of the aerial part and roots were all measured. The varieties of sugar cane showed similar responses for growth reduction as soil salinity increases, being considered moderately sensitive to salinity.

  10. Deep saline groundwater within the Canadian Shield

    International Nuclear Information System (INIS)

    Groundwaters have been sampled from depths greater than 1000 m within the Canadian Shield. The samples were obtained from boreholes in mines and from test drilling programs carried out as part of the Canadian Nuclear Fuel Waste Management Program. At the depths explored, water is found in fractures, shear zones and similar structural features. The salinity of the water is frequently very high, with total dissolved solids often exceeding 200 g.L-1. These saline waters can be classified as Ca-Na-Cl brines. Isotopic analyses for 2H and 18O show that these fluids are not modern, local meteoric waters which dissolve salts in sedimentary, metasedimentary or metamorphic rocks. The chemical and isotopic data suggest that all saline waters analyzed to date have a similar origin. This source is not well-understood but could be highly modified Paleozoic seawater, residual metamorphic fluids, or less likely, groundwaters that have been in contact with the rocks in the Canadian Shield for millions of years. In all cases the fluids appear to have been isolated from the biosphere for geological time periods. The existence of these highly saline fluids influences the Nuclear Fuel Waste Management Program in several areas. A major concern is the corrosion resistance of the radioactive waste containers. Saline waters may also influence the buffer and backfill and vault sealing materials, the rock mass and the waste form itself, although the effects may not always be deleterious. Corrosion of underground test equipment during the geoscience research phase is also a concern

  11. Salinity transfer in bounded double diffusive convection

    CERN Document Server

    Yang, Yantao; Ostilla-Mónico, Rodolfo; Sun, Chao; Verzicco, Roberto; Grossmann, Siegfried; Lohse, Detlef

    2015-01-01

    The double diffusive convection between two parallel plates is numerically studied for a series of parameters. The flow is driven by the salinity difference and stabilized by the thermal field. Our simulations are directly compared to experiments by Hage and Tilgner (\\emph{Phys. Fluids} 22, 076603 (2010)) for several sets of parameters and reasonable agreement is found. This in particular holds for the salinity flux and its dependence on the salinity Rayleigh number. Salt fingers are present in all simulations and extend through the entire height. The thermal Rayleigh number seems to have minor influence on salinity flux but affects the Reynolds number and the morphology of the flow. Next to the numerical calculation, we apply the Grossmann-Lohse theory for Rayleigh-B\\'{e}nard flow to the current problem without introducing any new coefficients. The theory successfully predicts the salinity flux both with respect to the scaling and even with respect to the absolute value for the numerical and experimental res...

  12. Biomarker-based salinity reconstruction immediately prior to the Messinian Salinity Crisis (Sorbas Basin, Spain)

    Science.gov (United States)

    Mayser, Jan Peter; Martins, Cesar; Flecker, Rachel; Pancost, Rich D.

    2014-05-01

    The salinity crisis which occurred in the Mediterranean at the end of the Miocene (5.97 to 5.33 Ma) was a time of large-scale environmental change and thick evaporite deposits formed both in the deep basins and on the surrounding margins. Late Miocene successions in the Sorbas Basin, south east Spain preserve sediments that were deposited immediately prior to the Messinian Salinity Crisis (MSC) and during the initial phase of gypsum precipitation (Sierro et al., 2001). Salinity changes are indicated by evaporite formation and fluctuations in faunal assemblages, but these provide threshold measurements only e.g. gypsum forms at a salinity of 130 psu. By analysing the lipid biomarker composition by GC and HPLC-MS after Soxhlet extraction of pre-MSC sediments we aim to reconstruct granular changes in salinity leading up to initial gypsum precipitation. The pre-MSC sediments comprise regular alternations of marine marls and terrigenous clays with interspersed diatomites. This lithological cyclicity is climatically forced by orbitally-driven changes in insolation (Krijgsman et al., 1999) such that specific lithologies are thought to accumulate during precession minima (homogeneous marls) and maxima (laminated marls). By targeting these lithologies for salinity reconstruction we can evaluate the orbital control on quantified environmental change. The reconstruction of the salinity is predominantly based on the ACE proxy introduced by Turich and Freeman (2011). The GDGT-based proxy can show differences over a wide range of salinity, because Archaea can survive over a much larger salinity range than haptophyte algae or other plankton and can therefore also record the salinity signal over a wider range. This makes it suitable for the broad salinity ranges leading up to the MSC e.g. ~35 to 130 psu. Turich et al. (2011) already have published 10 low resolution salinity values for pre-MSC sediments from Torrente Vaccarizzo and Serra Pirciata on Sicily. Our high resolution

  13. 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

  14. Rain Impact Model V2.0 for Sea Surface Salinity: A Flag for Salinity Stratification

    Science.gov (United States)

    Santos-Garcia, A.

    2015-12-01

    The Central Florida Remote Sensing Laboratory has analyzed Aquarius (AQ) sea surface salinity (SSS) and ESA's Soil Moisture Ocean Salinity (SMOS) retrievals in the presence of rain and has developed a Rain Impact Model (RIM V2.0) that predicts transient near-surface salinity stratification based upon the corresponding rain accumulation over the previous 24 hours and the effect of the wind speed. For both of the satellite SSS measurements, a common reference for comparison is the Hybrid Coordinate Ocean Model (HYCOM) for ocean salinity, but there is a significant mismatch between the remote sensing sampling depth of approximately 0.01 m and the typical range of 5 m to 10 m of in situ instruments. Under normal ocean conditions the upper layer of the ocean is well mixed and there is an approximately uniform salinity for the first 10 m depth; therefore satellite measurements are good estimates of the bulk salinity. Conversely, under rainy conditions, there is a dilution of the near-surface salinity that mixed downward by diffusion and mechanical mixing of gravity waves, where the wind speed information play a significant role in the model. This transient phenomena, known as salinity stratification, significantly modifies the salinity gradient in the upper 1 m of the ocean; and therefore invalidates the usual assumption of well-mixed salinity. Generally, these salinity stratifications dissipate in less than a couple of hours and the upper layer becomes well mixed at a slightly fresher salinity. The Rain Impact Model V2.0 is based on the RIM V1.0, previously published, which includes the rain accumulation effect but ignores the variations on wind speed using a constant vertical diffusivity value. This research addresses the effects of rainfall on the AQ and SMOS SSS retrieval using a macro-scale Rain Impact Model (RIM) in regions of high convective rain. This model, based on the superposition of a one-dimension eddy diffusion (turbulent diffusion) model, relates sea

  15. Biochar Mitigates Salinity Stress in Potato

    DEFF Research Database (Denmark)

    Akhtar, S S; Andersen, Mathias Neumann; Liu, Fulai

    2015-01-01

    A pot experiment was conducted in a climate-controlled greenhouse to investigate the growth, physiology and yield of potato in response to salinity stress under biochar amendment. It was hypothesized that addition of biochar may improve plant growth and yield by mitigating the negative effect of...... with the respective non-biochar control. Decreased Na+, Na+/K+ ratio and increased K+ content in xylem with biochar amendment also indicated its ameliorative effects on potato plants in response to salinity stress. The results suggested that incorporation of biochar might be a promising approach for...

  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. Reduction of Long-Term Bedrock Incision Efficiency by Short-Term Alluvial Cover Intermittency

    Science.gov (United States)

    Lague, D.

    2009-12-01

    Rapid mountain river incision through bedrock is an inherently stochastic process resulting from the long-term summation of flow and sediment discharge events at very variable rates and frequency. While the actual incision processes remains difficult to apprehend in situ and are the subject of ongoing research, there is no ambiguity on the inhibiting effect of a thick alluvial cover (several meters) on bed incision. This alluvial cover thickness strongly fluctuates as a function of stochastic supply of sediment by hillslopes, modulated by sediment transport and storage in the drainage network. Here, I study how this short-term stochasticity propagates into the long-term reduction of bedrock incision efficiency (the cover effect) at geological timescales, and how the upscaled cover model compare to existing empirical models. I introduce a new numerical model (SSTRIM, Stochastic Sediment Transport and River Incision Model) that resolves sediment transport and bedrock incision at daily timescales over a channel reach consisting of several trapezoidal cross-sections linked together. The model is run for thousands of years until a steady-state geometry is reached under the prevailing uplift, sediment supply and water discharge rates. The model incorporates (i) a stochastic sediment supply mimicking the pdf of sediment volume supplied by landsliding, (ii) a transport threshold and daily stochastic variations in water discharge, (iii) a freely evolving channel width and slope; (iv) an explicit treatment of alluvial thickness variations and corresponding bed incision reduction. Bed and bank incision are calculated as a function of bed and bank shear stress. Model results predict the existence of 2 cover dynamics regime: one in which the bed is almost permanently partially covered by sediment, and on in which intermittency dominates. In this later case, the cover effect operates over long-term by modulating the proportion of time where the channel is fully or not covered

  18. Alluvial Fans and Megafans Along the Southern Side of the Alps

    Science.gov (United States)

    Fontana, A.; Mozzi, P.

    2011-12-01

    The Po Plain extents for about 40.000 km2 and fills an area representing the foreland of the Alps and the foredeep of the Apennines. Towards East, the Po plain continues in the Venetian-Friulian Plain, which has an area of 10.000 km2. Along the Alpine piedmont sector the alluvial deposition has been related to the major Alpine rivers, that drain a total mountain catchement of about 50.000 km2, with a maximum elevation between 2800-4810 m. A major depositional phase occurred in the area during LGM (24-17 ka BP), when the fronts of the glaciers hosted in the main Alpine valleys reached the plain and fed the related fluvioglacial and fluvial systems. These experienced a large and widespread aggradation and led to the formation of several megafans (i.e. Isonzo, Tagliamento, Piave, Brenta, Chiese, Oglio, Adda, Ticino) and fans (e.g. Cellina, Astico, Serio, Lambro). The LGM megafans have an extent between 1000-3000 km2 and are characterized by a piedmont sector (10-25 km from the apex) of amalgamated gravels related to unconfined braided channels; the distal sector is fine-dominated and channels are sandy braided, whereas the meandering typology started from the terminal portion (40-60 km from apex). The thickness of LGM alluvial sedimentation spans between 30-20 m in the plain and thins to 10 m in the Adriatic seabed. Soon after the ice decay (since 17 ka BP), the sedimentary delivery from Alpine catchments to the plain stopped, mainly due to the formation of intramontane lakes trapping the bedload. Thus, an erosive phase affected the whole pede-Alpine sector, leading the Alpine rivers to entrench for tens of meters in the apical gravelly portions of their fans or megafans. In the Venetian-Friulian Plain a single incision characterize the apical portion, whereas 2-5 fluvial incisions developed in the distal sector, up to the present coastal area, where they have a depth of 15-30 m and a width of 600-2000 m. The incised-valley fills (IVF) have been recognized in the

  19. Salinity Training for Agricultural Scientists from Iraq

    International Nuclear Information System (INIS)

    Soil and water salinity is one of the major problems affecting agricultural productivity and food security in Iraq. The main challenges are: (i) to develop appropriate irrigation technologies and scheduling to ensure year-round food production, (ii) to assess tolerance of different crops (varieties) to soil and irrigation water salinity and (iii) to reduce further salinization of soil and water. It is against this background that the Department of Science and Technology, Iraq, requested the SWMCN Subprogramme to provide intensive training for five professional and technical fellows on 'Managing soil and water in salt-affected soils for enhanced crop productivity using isotopic techniques' from 30 August to 8 October 2010 at the IAEA Laboratories, Seibersdorf. The programme consisted of: (i) lectures on soil and water salinity and how crop growth is affected (ii) practical glasshouse and field training on the monitoring of soil and water salinity and soil-plant-water interactions and finally (iii) data analysis and interpretation. During the first week, the trainees were provided with an introduction to the principles of water movement in the soil-plant system and the factors influencing soil and water salinity and how salinity affects plant growth. During the subsequent weeks they were trained under both glasshouse and field conditions on soil water and salinity measurements. Training activities included glasshouse and field experimental design, electrical conductivity measurements in soil and water, soil moisture measurements using a neutron probe and conventional tools such as capacitance probes and Time Domain Reflectometry (TDR). The fellows also received training on the installation of suction cups for collecting soil water and the use of tensiometers for measuring water availability for crops. As part of the training programme, two glasshouse experiments were established to study: (i) the effect of different levels of salt concentration in the soil on the

  20. 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

  1. 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

  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. 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

  4. 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

  5. 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

  6. Effect of Alternating Saline and Non-saline Conditions on Emergence and Seedling Growth of Rice

    OpenAIRE

    M.Z. Alam; M.A.A. Bhuiya; M.A. Muttaleb; M.M. Rashid

    2004-01-01

    A pot experiment in glasshouse was conducted with a single salinity level of 10.5 dS m-1 to study the effect of alternating saline and non-saline conditions on emergence and seedling growth of two rice cultivars (IR8 and V3) differing in salt tolerance. A split-plot design was used with three replications. The results demonstrated that rice seedlings, 1 to 3 weeks after emergence, proved to be very salt-sensitive. There was about 80% reduction in stand establishment in 10.5 dS m-1 salt (about...

  7. Saline agriculture: A technology for economic utilization and improvement of saline environments (abstract)

    International Nuclear Information System (INIS)

    The salinity problem is one of the severe constraints for agriculture in Pakistan. In a socio-economic and salinity and drainage survey over an area of about 25000 acres of salt-affected land recently, crop production is found to be very low. Livestock is underfed and malnourished. Pakistan has spent and allocated over one billion US dollars on Salinity Control and Reclamation Projects (SCARP), of course, with dubious results. Over the years, a Saline Agriculture Technology has been developed as a cheap alternative at NIAB for comfortably living with salinity and to profitably utilize saline land rather than its reclamation. The soil improvement is a fringe benefit in this approach. The Saline Agriculture Technology has been tested at laboratory level, at field stations and at farms of some progressive farmers. Now we are sharing this technology with farming communities through a 'Saline Agriculture Farmer Participatory Development Project in Pakistan', with assistance from the National Rural Support Programme. The new project has been launched simultaneously in all four provinces of Pakistan on 25000 acres of salt-affected land. Under this project seeds of salt tolerant crop varieties wheat, cotton, rice, castor, brassica and barley and saplings of trees/shrubs, e.g. Acacia ampliceps, A. nilotica, Casuarina glauca, ber, jaman, etc selected for development work in various institutions of Pakistan are being provided to farmers. Know-how on new irrigation techniques like bed-and-corrugation and bed-and-furrow, agronomic practices like laser land leveling, planting on beds and in auger holes and soil/water amendment practices (use of gypsum and mineral acids) are being shared with farmers. These interventions are quite efficient, save water up to 40% and enable farmers to utilize bad quality water. In general, farmers are being familiarized with prevalent animal diseases, nutritional problems and prophylactic techniques. They are being helped in developing Saline

  8. Variations in alluvial style of Tertiary units in response to tectonism, Las Monas area, middle Magdalena valley, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, D.W.; Siemers, C.T.

    1989-03-01

    Detailed sedimentologic and petrographic analyses of Tertiary alluvial sandstone outcrops within and east of producing oil fields in the Las Monas area in Colombia, South America, indicate that depositional style changed from fluvial-deltaic to braided streams atop alluvial fans to high-sinuosity meandering streams in response to uplifts in the surrounding areas. Diverse paleocurrent trends in the Tertiary formations in the perimeter area demonstrate that streams flowed northeast and northwest. Streams in the oil field had easterly and southerly components. Source areas contributing sediment were different and reflected uplifts to the west and south of the Las Monas area. Petrographic composition of sandstones that have easterly and southerly paleocurrent trends in the field area contain more feldspar and less polycrystalline strained quartz than sandstones having a northerly trend in the perimeter area. Sandstones in the field area represent an unroofing of a western granitic terrain, possibly in the ancestral Central Cordillera.

  9. 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.

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. Evaluation of lettuce genotypes for salinity tolerance

    Science.gov (United States)

    Lettuce is one of the most commonly used salad vegetables and considered to be a relatively salt sensitive crop. Salinity is a major constraint to crop production in all important lettuce districts of the U.S., and the water quality problem is exacerbated by the climate change. In order to identify ...

  4. 40 CFR 230.25 - Salinity gradients.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Salinity gradients. 230.25 Section 230.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL Potential Impacts...

  5. An inside view on salinity tolerance

    International Nuclear Information System (INIS)

    Full text: Nuclear magnetic resonance (NMR) imaging has a range of biological uses NMR imaging of sodium (Na)is potentially a valuable tool for understanding physiological adaptations to salinity. The technique allows spatial localization of sodium in tissues and can give information about uptake and differing concentrations of Na in cells and tissues. Until now, the use of in vivo sodium NMR imaging in plant biology has been limited. Our study illustrates possible applications of this technique. Two species of the Casuarinaceae were compared Casuarina glauca is highly salinity-tolerant while Allocasuarina torulosa has little salinity tolerance. Both types of plants were exposed to various NaCl concentrations prior to imaging Sodium (23Na) imaging through seedling stems was combined with anatomical proton (1H) imaging and light microscopy of stem sections, allowing a comparison of sodium uptake and tissue localization. For a given NaCl concentration after a given time, Allocasuarina torulosa absorbed more Na than Casuarina glauca. Furthermore, whereas the Na was restricted to the primary xylem, phloem and parenchyma ray and pith tissues in Casuarina glauca stems, in Allocasuarina torulosa it was more homogeneously distributed throughout the stem tissues. This preliminary study indicates that differences in salinity tolerance between the two species may be explained by differences in salt uptake and tissue localization

  6. Salinity Tolerance Turfgrass: History and Prospects

    Directory of Open Access Journals (Sweden)

    Md. Kamal Uddin

    2013-01-01

    Full Text Available Land and water resources are becoming scarce and are insufficient to sustain the burgeoning population. Salinity is one of the most important abiotic stresses affecting agricultural productions across the world. Cultivation of salt-tolerant turfgrass species may be promising option under such conditions where poor quality water can also be used for these crops. Coastal lands in developing countries can be used to grow such crops, and seawater can be used for irrigation of purposes. These plants can be grown using land and water unsuitable for conventional crops and can provide food, fuel, fodder, fibber, resin, essential oils, and pharmaceutical products and can be used for landscape reintegration. There are a number of potential turfgrass species that may be appropriate at various salinity levels of seawater. The goal of this review is to create greater awareness of salt-tolerant turfgrasses, their current and potential uses, and their potential use in developing countries. The future for irrigating turf may rely on the use of moderate- to high-salinity water and, in order to ensure that the turf system is sustainable, will rely on the use of salt-tolerant grasses and an improved knowledge of the effects of salinity on turfgrasses.

  7. Salinity tolerance turfgrass: history and prospects.

    Science.gov (United States)

    Uddin, Md Kamal; Juraimi, Abdul Shukor

    2013-01-01

    Land and water resources are becoming scarce and are insufficient to sustain the burgeoning population. Salinity is one of the most important abiotic stresses affecting agricultural productions across the world. Cultivation of salt-tolerant turfgrass species may be promising option under such conditions where poor quality water can also be used for these crops. Coastal lands in developing countries can be used to grow such crops, and seawater can be used for irrigation of purposes. These plants can be grown using land and water unsuitable for conventional crops and can provide food, fuel, fodder, fibber, resin, essential oils, and pharmaceutical products and can be used for landscape reintegration. There are a number of potential turfgrass species that may be appropriate at various salinity levels of seawater. The goal of this review is to create greater awareness of salt-tolerant turfgrasses, their current and potential uses, and their potential use in developing countries. The future for irrigating turf may rely on the use of moderate- to high-salinity water and, in order to ensure that the turf system is sustainable, will rely on the use of salt-tolerant grasses and an improved knowledge of the effects of salinity on turfgrasses. PMID:24222734

  8. About uncertainties in practical salinity calculations

    Directory of Open Access Journals (Sweden)

    M. Le Menn

    2009-10-01

    Full Text Available Salinity is a quantity computed, in the actual state of the art, from conductivity ratio measurements, knowing temperature and pressure at the time of the measurement and using the Practical Salinity Scale algorithm of 1978 (PSS-78 which gives practical salinity values S. The uncertainty expected on PSS-78 values is ±0.002, but nothing has ever been detailed about the method to work out this uncertainty, and the sources of errors to include in this calculation. Following a guide edited by the Bureau International des Poids et Mesures (BIPM, this paper assess, by two independent methods, the uncertainties of salinity values obtained from a laboratory salinometer and Conductivity-Temperature-Depth (CTD measurements after laboratory calibration of a conductivity cell. The results show that the part due to the PSS-78 relations fits is sometimes as much significant as the instruments one's. This is particularly the case with CTD measurements where correlations between the variables contribute to decrease largely the uncertainty on S, even when the expanded uncertainties on conductivity cells calibrations are largely up of 0.002 mS/cm. The relations given in this publication, and obtained with the normalized GUM method, allow a real analysis of the uncertainties sources and they can be used in a more general way, with instruments having different specifications.

  9. Wave Induced Saline Intrusion in Sea Outfalls

    DEFF Research Database (Denmark)

    Larsen, Torben; Burrows, Richard

    Experimental and numerical studies have shown that the influence of wave increases the tendency of saline intrusion in multi-riser sea outfalls. The flow field in the diffusor under such unsteady and inhomogeneous circumstances is in general very complex, but when sufficient wave energy is...

  10. Environmental geophysics mapping salinity and water resources

    NARCIS (Netherlands)

    Dent, D.

    2007-01-01

    Salinity and fresh water are two sides of the same coin, most conveniently measured by electrical conductivity; they can now be mapped rapidly in three dimensions using airborne electromagnetics (AEM). Recent developments in the calibration of airborne data against in-field measurements and addition

  11. Evaluation of soil salinity leaching requirement guidelines

    Science.gov (United States)

    Water for irrigation is a major limitation to agricultural production in many parts of the world. Use of waters with elevated levels of salinity is one likely option to meet the supply of increased demands. The sources of these waters include drainage water generated by irrigated agriculture, munici...

  12. Determination of the stability of the uranyl ion sipped in {tau}-hydrogen phosphate of zirconium in sodic form; Determinacion de la estabilidad del ion uranilo sorbido en {tau}-hidrogenofosfato de zirconio en forma sodica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Fernandez V, S.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Drot, R.; Simoni, E. [Universite de Paris-Sud-XI, Institut de Physique Nucleaire d' Orsay, Groupe de radiochimie, Bat. 100, 91406 Orsay (France)]. e-mail: edo@nuclear.inin.mx

    2005-07-01

    The stability of the uranyl sipped in the zirconium {tau}-hydrogen phosphate in sodic form ({tau}-NaZrP), was carried out characterizing the complexes formed by Laser spectroscopy in the visible region and by X-ray photoelectron spectroscopy. The material was prepared by a new synthesis technique working in nitrogen atmosphere and to low temperatures. The sorption of the uranyl ion was made in acid media with concentrations of 10{sup -4} and 10{sup -5} of uranyl nitrate and with ion forces of 0.1 and 0.5 M of NaClO{sub 4}. The spectra of induced fluorescence with laser (TRLFS) show that the uranyl is fixed in very acid media in three well differentiated species, to pH less acid, the specie of long half life disappears and are only those of short half life. The results of the binding energy obtained by XPS indicate that the binding energy of the uranyl confer it a stable character to the complex formed in the {tau}-NaZP, that makes to this material appropriate to retain to the uranyl in solution to high ion forces and in acid media. (Author)

  13. End-Pleistocene to Holocene paleoenvironmental record from piston corer samples and the challenge of stratigraphic correlation of playa sediment data with a connected alluvial apron from Damghan Basin, Iran

    Science.gov (United States)

    Büdel, Christian; Hoelzmann, Philipp; Wennrich, Volker; Majid Padashi, Sajed; Baumhauer, Roland

    2015-04-01

    The study yields a first characterization and correlation of the end-Pleistocene to Holocene sediment archive of playa and playa lake deposits in the Damghan Basin, northern Iran. The Basin sediments are deposited since Mio- and Pliocene, which is valid for the connected alluvial fans, too. These are covering the area between the playa and mountains and while prograding from the mountain ranges they deliver gravels and fine-sediments to the basins sink. The processes on the studied alluvial apron are described and dated already and can be explained in seven morphodynamic phases, which are linked to a general lake level high-stand in north-east Iran at about 8000-9000 years ago. If and how these phases are passed on from the alluvial record down to the playa sediment record is aim of this study. Today the salt pans margins are highly affected by salt tectonic drifting and access was suboptimal. Only here drilling could be performed through about 280 centimeters of salt-crust unfrequently intercalated with loamy layers. For yielding undisturbed playa sediment records sampling was performed with inliner-tubes deployed in a piston corer (Kullenberg type). Thus at two different drilling sites in summation seven cores could be taken, down to a maximum depth of 129 cm and 1000 cm. Back in Germany the cores had been opened and initially described, photographed and optically scanned with a core logger. Regarding future studies, the aim was a best possible comprehensive documentation of the cores. Therefore basically grainsize measurements (laser diffraction), multi element analyses (XRF, ICP-OES, titrimetry) and mineralogical measurements (XRD) had been deployed on samples taken from every single previously identified layer. Continuous elemental data was secured by use of a XRF-scanning core logger. The sedimentological description together with laboratory element analyses shows saline conditions in the first three meters coincide with general coarser grain sizes. The next

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

    OpenAIRE

    Cappuyns, Valérie; Swennen, Rudy

    2003-01-01

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

  15. 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...

  16. 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.

  17. Effects of land use and hydrogeology on the water quality of alluvial aquifers in eastern Iowa and southern Minnesota, 1997

    Science.gov (United States)

    Savoca, Mark E.; Sadorf, Eric M.; Linhart, S. Mike; Akers, Kim K.B.

    2000-01-01

    Ground-water samples were collected from monitoring wells at 31 agricultural and 30 urban sites in the Eastern Iowa Basins study unit during June–August 1997 to evaluate the effects of land use and hydrogeology on the water quality of alluvial aquifers. Ground-water samples were analyzed for common ions, nutrients, dissolved organic carbon, tritium, radon-222, pesticides and pesticide metabolites, volatile organic compounds, and environmental isotopes.

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

    OpenAIRE

    Petra Souvent; Goran Vižintin; Sašo Celarc; Barbara Čenčur Curk

    2014-01-01

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

  19. 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 ...

  20. The effects of the structure on the mechanical behaviour of young Holocene alluvial materials from the Bormida River (Italy) and Turia River (Spain)

    OpenAIRE

    Carrión Carmona, Miguel Ángel

    2016-01-01

    [EN] The understanding of the mechanical behaviour of natural intact soils is central to engineers when designing new structures. The research carried in this thesis focused on investigating the effects of the naturally occurring in-situ structure on the mechanical behaviour of two shallow recently deposited Holocene alluvial materials, the Bormida River silts (BRS) from Italy and the Valencia silty soils (VSS) from the alluvial plains of the Turia River, Spain. These types of deposits are fr...

  1. Sodium kinetics in hypertonic saline abortion

    International Nuclear Information System (INIS)

    The sodium kinetics of hypertonic saline abortions have been followed by measuring the radioactivity and the sodium concentrations in amniotic fluid, maternal plasma, urine, the foetus and placenta after intrauterine installation of 20% hypertonic saline labelled with 22Na in order to determine the reason for abortion of a dead foetus in 24 to 48 hours, and reasons for sodium reactions. There is dilution of the 300 ml of amniotic fluid to a maximum of 1.5 to 2.0 litres in an exponential fashion, by the influx of mainly maternal water, slowing after 8 hours. There is an exponential type of increase in plasma radioactivity, also slowing after 8 hours. However, equilibration is never reached, the specific activity of the amniotic fluid remaining 10 times that of the plasma, and the sodium concentration 3 times that of the plasma. The urine equilibrates with the plasma, and about 3% of the administered dose is lost in 22 hours. The largest foetus and placenta picked up the least radioactivity. Thus, a more mature foetus may be protected to some degree against the hypertonic saline action; this has been observed clinically. Hyperkaliaemia was found in all four subjects, and hypoglycaemia occurred sporadically. These were not accompanied by any symptoms. Factors associated with expulsion of the dead foetus are dehydration and decreased circulation associated with fibrinoid necrosis of the placenta, which may also account for cessation of equilibration between maternal plasma and amniotic fluid. Although no saline reactions occurred, the role of extrauterine deposition of hypertonic saline, as shown in one subject, might be considered. (author)

  2. Management of saline soils in Israel

    International Nuclear Information System (INIS)

    The main soil salinity problem in Israel is the danger of gradual salinization as a result of excessively efficient water management. Aquifer management is aimed at preventing flow of groundwater into the ocean, causing a creeping salinization at a rate of about 2 ppm per year. Successful efforts to improve irrigation efficiency brought with them the danger of salt accumulation in the soil. A ten-year monitoring programme carried out by the Irrigation Extension Service at 250 sampling sites showed that appreciable salt accumulation indeed occurred during the rainless irrigation season. However, where annual rainfall is more than about 350 mm this salt accumulation is adequately leached out of the root zone by the winter rains. Soil salinity in the autumn is typically two to three times that in the spring, a level which does not affect yields adversely. In the drier regions of the country long-term increasing soil salinity has been observed, and leaching is required. This is generally accomplished during the pre-irrigation given in the spring, whose size is determined by the rainfall amount of the preceding winter. The increasing need to utilize brackish groundwater and recycled sewage effluent requires special measures, which have so far been successful. In particular, drip irrigation with its high average soil-water potential regime and partial wetting of the soil volume has achieved high yields under adverse conditions. However, the long-term trend of water-quality deterioration is unavoidable under present conditions, and will eventually necessitate either major changes in agricultural patterns or the provision of desalinated water for dilution of the irrigation water. (author)

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. New data concerning the Late Quaternary drainage evolution on the Someş River alluvial fan

    Directory of Open Access Journals (Sweden)

    Delia-Elena ROBU

    2014-11-01

    Full Text Available The study area is located in the north-eastern part of the Pannonian Basin, on the romanian teritory, with a surface of over 3,600 square kilometers. With elevations of 20-30 m above the Timiş and Criş plains, is the highest low-western romanian plains (100 – 160 m absolute altitudes, the surface extending on both sides of Someş River. This study aims to report new information on Late Quaternary evolution of fluvial discharge on the surface of Someş alluvial fan.Numerous relict fluvial morphologies were recognized on the surface ofSomeşRiveralluvial Plain, by analyzing mainly the fluvial morphologies visible on the second austro-hungarian military maps (reference moment: ca. 1860, and on recent ortophotoplans (reference moment: 2005. The identified palaeochannel types (braided, meandering and morphometry (large scale meanders vs. small scale meanders, the concentration of these relict features on distinct palaeodrainage directions, the relation of them with the recent fluvial drainage of the area (intersected, partly/ totally used by present day misfit channels, suggest a complex Late Quaternary history of the lower course ofSomeşRiver. 

  12. Vulnerability and Pollution Risks in the Alluvial Aquifer of Tebessa-Morsott

    Directory of Open Access Journals (Sweden)

    S. Kachi

    2007-01-01

    Full Text Available We studied the vulnerability and risks of pollution of the alluvial aquifer of Tebessa-Morsott that ranks amongst the major groundwater reservoirs of the region. The method used to asses groundwater vulnerability was the DRASTIC method, based on seven parameters that affect and control the groundwater flow: Depth to groundwater, Impact of the unsaturated zone, net recharge, aquifer media, hydraulic conductivity, soil media, topography. These parameters were obtained from data field, synthetic maps relative to the area considered and then identified within each cell after discretization of the studied area in regular square cells. For each cell, DRASTIC rating for each parameter was multiplied by the DRASTIC weight for that cell and summed to determine the DRASTIC index. A detailed vulnerability map was obtained, showing four classes of potential pollution of the aquifer. Check analysis of the quality of groundwater within these zones are carried out in order to assess the risks of contamination. Pollution by nitrates occurs especially in the wells of low depth, but also in certain drillings for drinking water, whereas bacteriological pollution is observed only in the domestic wells.

  13. 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...

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

    International Nuclear Information System (INIS)

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

  15. Forest area and distribution in the Mississippi alluvial valley: Implications for breeding bird conservation

    Science.gov (United States)

    Twedt, D.J.; Loesch, C.R.

    1999-01-01

    Knowing the current forest distribution and patch size characteristics is integral to the development of geographically defined, habitat-based conservation objectives for breeding birds. Towards this end, we classified 2.6 million ha of forest cover within the Mississippi Alluvial Valley using 1992 thematic mapper satellite imagery. Although historically this area, from southern Illinois to southern Louisiana, was dominated by forested wetlands, forest cover remains on less than 25% of the floodplain. Remaining forest cover is comprised of > 38,000 discrete forest patches > 2 ha. Mean patch area (64.1?5.2 ha; 0 ?SE) was highly skewed towards small fragment size. Larger patches had a higher proportion of more hydric forest cover classes than did smaller patches which had a higher proportion of less hydric forest cover classes. Public lands accounted for 16% of remaining forested wetlands. Fewer than 100 forest patches exceeded our hypothesized habitat objective (4000 ha minimum contiguous forest area) intended to support self-sustaining populations of forest breeding birds. To increase the number of forest patches exceeding 4000 ha contiguous area, and thereby increase the likelihood of successful forest bird conservation, we recommend afforestation adjoining existing forest fragments ?1012 ha and focused within designated Forest Bird Conservation Regions.

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

    Science.gov (United States)

    Goswami, Pradeep K.; Pant, Charu C.; Pandey, Shefali

    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 morphotectonic 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.

  17. 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.

  18. 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

  19. 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.

  20. Biodiversity patterns of soil ciliates along salinity gradients.

    Science.gov (United States)

    Zhao, Feng; Xu, Kuidong

    2016-04-01

    We evaluated ciliate diversity in saline soils with a salinity range from 6.5 to 65psu by the morphological method of the Ludox-quantitative protargol stain (QPS) and the molecular techniques of ciliate-specific clone library and denaturing gradient gel electrophoresis. No active ciliates could be detected with the Ludox-QPS method, while high molecular diversity of ciliates was found. The highest ciliate molecular diversity was obtained from the soil at salinity of 8.9psu, moderate diversity was found at salinity of 6.5psu, and the diversity sharply decreased at salinity of 50.5psu. By contrast, the number of ciliate classes clearly decreased with increasing soil salinity: six, five, four and two classes from sites with salinity of 6.5psu, 8.9psu, 29.5psu and 50.5psu, respectively. Ciliate diversity pattern is different from that of bacteria, whose diversity is also high in extremely saline environments. Meanwhile, the composition of ciliate community was significantly different along salinity gradient. Colpodea and Oligohymenophorea were diverse in soils at salinity less than 29.5psu, while absent in soils with salinity above 50.5psu. BIOENV analysis indicated soil salinity and water content were the main factors regulating the distribution of ciliates in saline soils. PMID:26773903

  1. Transport Characteristics of Soil Salinity in Saline-alkali Land under Water Storage and Drainage Conditions

    Institute of Scientific and Technical Information of China (English)

    Juan; LI; Jichang; HAN

    2015-01-01

    To test the variation and transport of soil salinity in saline- alkali land under water storage and drainage treatments,an experimental model was established in Fuping,Shaanxi Province,2009. The variation of soil salinity during 0- 160 cm soil depth under the two treatments was determined and analyzed. Results showed that the average soil water content under water storage treatment was 4. 47% higher than that under drainage treatment,which means that the water storage treatment could help to improve soil moisture to satisfy the crop’s growth needs. The profile distribution of soil soluble solids( TDS),anion( Cl-,HCO3-,SO2-4) and cation( Ca2 +,Na+,K+) content and the variation of soil p H were also measured and analyzed. PCA( Principal Component Analysis) was used to explore the relationship between the soil salinity and its ions,which showed that the water storage treatment could significantly decrease the surface salinity of soil and accelerate the desalination of topsoils,and finally,the soil quality was improved significantly,demonstrating that the water storage treatment has a remarkable effect on soil salinity management.

  2. Improving the tolerance of Vicia faba against environmental salinity resulted from the irrigation with sea water by using KNO3 and (NH4)2 SO4 as chemical osmoregulators

    International Nuclear Information System (INIS)

    The familiar solutes, Na+, K+, Ca2+, Mg2k+, Cl-, PO43-, SO42-, soluble carbohydrates, amino acids and soluble proteins, which play a role in osmotic adjustment were estimated to investigate the role of potassium nitrate and ammonium sulphate as osmoregulators and their effects on the solutes composition. Vicia faba L. was cultivated and irrigated with 5, 10, 15 and 20 % (v:v) sea water. The plants were divided to three groups. The first was irrigated with sea water only. The second was treated with 5 mM KNO3 while the third was treated with 5mM (NH4)2SO4. The plants were left to grow until flowering stage. The results indicated that the non-treated group increased the soluble carbohydrates in the roots to avoid the influx of sodium. The treatment with KNO3 decreased the sodicity (SAR) while (NH4)2SO4 treatment decreased the SK: Na value in the shoots at higher salinity. The availability of nitrogen as nitrate or ammonium ions enhances the accumulation of soluble carbohydrates in shoots. The plants of all groups were depended on Ca2+, as compatible solute more than Na+, and K+.

  3. Design and implementation of equipment for monitoring the salinity in the subsoil

    Directory of Open Access Journals (Sweden)

    Mariano Norzagaray Campos

    2012-09-01

    Full Text Available Geochemical exploration equipments to explore the contaminants and structures geological in the subsoil come from abroad are expensive and sometimes parts for replacement are not available in the market. So it is necessary design apparatus that meet cover these needs. To the monitoring of variations in salinity there is semi-automatic equipment, but it always has difficult to manage. However, is not equipment for the indirect study of salinity in the subsoil. In this work was design equipment for measurement the apparent resistivity in the subsoil, at same time allow know the salinity, as well as the detection of any pollutant in groundwater. For make it, was selected a design of earthing systems, with electronic hardware which were jointed for apply to subsoil a direct current (DC through an array dipole-dipole and vertical electric sounding, with brass and stainless steel electrodes. In the earthing systems the electrodes were collocated in the equidistant line between the detectors of potential and current. A geometric factor (K, that depend on theelectrodes distance and direct current (I injected in the electrodes A and B, was used for measure the potential difference between the electrodes M and N; after was calculate the resistivity point to point for obtain a subsoil tomography geoelectrical. The equipment was calibrated with minimum error (rms < 2% whit respect to curves obtained in similar commercial equipment. On this situation, in this work was modernized and automated an equipment to determine thesalinity of the subsoil. The instrument was tasted in the micro basin Texcoco, State of Mexico, to define the environment geometry formed by alluvial or lake sediments from igneous rocks (andesites, rhyolites and tuffs vitreous or “tepetates” which by its mineralogical composition allowed to the lateral resistivity be associate with free components trace from the aquifer: Cd, Cu, Cr, Co, Ni, Pb or Zn and others. This method constitutes

  4. Global Temperature and Salinity Profile Programme (GTSPP) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Temperature-Salinity Profile Programme (GTSPP) develops and maintains a global ocean temperature and salinity resource with data that are both up-to-date...

  5. Saline Systems: A research journal bridging gene systems and ecosystems

    OpenAIRE

    DasSarma, Shiladitya

    2005-01-01

    Saline Systems addresses the publication needs of scientists conducting basic and applied research on coastal and inland saline environments and their flora and fauna. The journal covers research at all levels, from individual genes to whole genomes and entire ecosystems. Rapid progress in the molecular biology and microbial ecology of halotolerant and halophilic organisms and the sensitivity of many saline environments warrants an online journal with fast turnaround times. Many saline enviro...

  6. Hurricane-induced failure of low salinity wetlands

    OpenAIRE

    Howes, Nick C.; FitzGerald, Duncan M.; Hughes, Zoe J.; Georgiou, Ioannis Y.; Kulp, Mark A.; Miner, Michael D.; Smith, Jane M.; Barras, John A.

    2010-01-01

    During the 2005 hurricane season, the storm surge and wave field associated with Hurricanes Katrina and Rita eroded 527 km2 of wetlands within the Louisiana coastal plain. Low salinity wetlands were preferentially eroded, while higher salinity wetlands remained robust and largely unchanged. Here we highlight geotechnical differences between the soil profiles of high and low salinity regimes, which are controlled by vegetation and result in differential erosion. In low salinity wetlands, a wea...

  7. 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

  8. Palaeoclimatic Indicators of China's Quaternary Saline Lake Sediments and Hydrochemistry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the authors classify saline lake sediments into the cold, warm and eurythermal phases, reveal the consistency between the zoning of hydrochemical types of modern saline lake water and climatic zoning and give climatic parameters under the conditions of typical cold phase (mirabilite and natron), warm phase (thenardite) and slightly warm phase (bloedite) saline lake deposition.

  9. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Directory of Open Access Journals (Sweden)

    W. A. Timms

    2012-04-01

    Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, potential evapotranspiration >2000 mm yr−1 such as parts of Australia's Murray-Darling Basin (MDB. In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m−1 with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low

  10. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Science.gov (United States)

    Timms, W. A.; Young, R. R.; Huth, N.

    2012-04-01

    The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (evapotranspiration >2000 mm yr-1) such as parts of Australia's Murray-Darling Basin (MDB). In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8-1.2 m depth under perennial vegetation and at 2.0-2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91-229 t ha-1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m-1 at 21 to 37 m depth (N = 5), whereas deeper groundwater was less saline (290 mS m-1) with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM) software package predicted deep drainage of 3.3-9.5 mm yr-1 (0.7-2.1% rainfall) based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total), and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditions after changes in land use and a thick clay dominated vadose zone

  11. Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia

    Directory of Open Access Journals (Sweden)

    W. A. Timms

    2011-11-01

    Full Text Available The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, such as parts of Australia's Murray-Darling Basin (MDB. In this unique study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥10 m depth that is not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5, whereas deeper groundwater was less saline (290 mS m−1 with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total, and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditionsafter changes

  12. Growth responses of the mangrove Avicennia marina to salinity: development and function of shoot hydraulic systems require saline conditions

    OpenAIRE

    Hoa T. Nguyen; Stanton, Daniel E.; Schmitz, Nele; Farquhar, Graham D.; Ball, Marilyn C.

    2015-01-01

    Background and Aims Halophytic eudicots are characterized by enhanced growth under saline conditions. This study combines physiological and anatomical analyses to identify processes underlying growth responses of the mangrove Avicennia marina to salinities ranging from fresh- to seawater conditions.

  13. Amoebae and Legionella pneumophila in saline environments

    OpenAIRE

    Gast, Rebecca J.; Moran, Dawn M.; Dennett, Mark R.; Wurtsbaugh, Wayne A.; Amaral- Zettler, Linda A.

    2011-01-01

    Amoeboid protists that harbor bacterial pathogens are of significant interest as potential reservoirs of disease-causing organisms in the environment, but little is known about them in marine and other saline environments. We enriched amoeba cultures from sediments from four sites in the New England estuarine system of Mt. Hope Bay, Massachusetts and from sediments from six sites in the Great Salt Lake, Utah. Cultures of amoebae were enriched using both minimal- and non-nutrient agar plates, ...

  14. 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

  15. Simulation of alluvial channel migration processes with a two-dimensional numerical model

    Science.gov (United States)

    Duan, Guohong

    An improved two dimensional numerical model for simulating the complicated meandering initiation, migration and widening processes of alluvial channels is presented in this research. The flow field simulation is obtained initially by the CCHE2D hydrodynamic model, which is obviously inadequate to predict the three-dimensional flow field in a channel bend. A set of empirical functions is proposed to convert the depth-averaged, two-dimensional flow field into an approximated three-dimensional one. As a result, a more realistic bed shear stress is predicted. Applying this enhanced model, the simulations of morphological processes in a channel bend are found to be more realistic than those produced by a traditional two-dimensional model. Due to the limitation of existing physical data, the CCHE3D after having been verified by physical models is employed as a computational experimentation flume to generate sufficient amount of data for establishing the empirical functions, so that the improved two-dimensional model can be nearly as accurate as three-dimensional models without having to solve three-dimensional numerical equations. In this study, the flow field of a meander channel is initially predicted by CCHE2D hydrodynamic model. By applying empirical functions to the flow field and bed shear stress field, the results of CCHE2D model are very close to those of CCHE3D. The predicted bed shear stress and velocity profiles of this enhanced CCHE2D are also in good agreements with the experimental data. Therefore, the hypothesis that an improved two-dimensional computational model can be applied to simulate three-dimensional physical processes adequately and cost-effectively is proved. In the sediment transport model, both bed load and suspended load are considered. The sediment incipient motion is affected by both the longitudinal and the transversal bed slope. In addition to the bed load transport due to bed shear stress, bed load transport in the transversal direction

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

    Science.gov (United States)

    Lorah, Michelle M; Cozzarelli, Isabelle M; Böhlke, J K

    2009-04-01

    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

  17. 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.

  18. 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

  19. 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

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

    Science.gov (United States)

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

    2015-04-01

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

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

    International Nuclear Information System (INIS)

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

  2. 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

  3. 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.

  4. 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

  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. Organic manure of the corn (Zea mays L.) in alluvial soils of intermediate climate

    International Nuclear Information System (INIS)

    With the purpose to evaluate the effect on the yield of com ICA V.303 variety, using four sources of organic matter (hen manure, pig manure, cow manure, earthworm manure) in two doses (500 and 1.000 kg/ha), compared with a chemical treatment (300 kg/ha of 10-30-10 plus 150 kg of urea), and a control, an experiment was carried out at Tulio Ospina Research Center, located at Bello (Antioquia), with 1.320 m.s.n.m. The experiment was established using an alluvial soil (tropofluvent), frank, with low content of organic matter (3.1%), and potassium (0.11 meq/l00 g), and medium content of phosphorus (2 ppm). The results, after four consecutive harvests on the same plots, showed highly significative differences among treatments, compared with the control. The highest yield (4.709 kg/ha) was obtained with the chemical treatment (300 kg/ha of 10-30-10 plus 150 kg of urea). The addition of 500 and 1.000 kg/ha of hen manure and pig manure showed an average yield of corn of 4.315,4.539 .4.246, and 4.487 kg/ha respectively. the control only produced 2.620 kg/ha. The great profitability was obtained with 500 kg/ ha of cow manure, 1.000 kg/ha of pig manure and the chemical treatment (300 kg/ha 10-30-10 and 150 kg/ha of urea y 1.000 kg/ha hen manure). There were not significative differences between the chemical fertilization and the organic fertilization; these results show that organic matter is an alternative for fertilization with respect to the development of a sustained and biological agriculture

  7. Salinization mechanisms in semi-arid regions

    International Nuclear Information System (INIS)

    During a period of three years the basins of the Pereira de Miranda and Caxitore dams, located in the crystalline rock area of Ceara, Brazil, were studied in order to determine the mechanisms of salinization of their waters. Isotope methods (18O/16O) and hidrochemistry (determination of the of the maior ions) were applied to surface, underground and rain water in this study. An isotope model was designed and applied to the determination of evaporation and percolation of dams in semi-arid zones during the dry season. The results are compared to those from a conventional chemical model. As causes of salinization of the water in the dams, the contributions of the rain itself and the lixiviation of the soil are quantified. An interaction between the dams and the underground water is imperceptible. The salinization of the underground water is attributed to recharge of the aquifer with rain water from the surface runoff followed by evaporation of the water rising, due to capilarity, in a one-directional flow to the surface. (Author)

  8. Deep roots of the Messinian salinity crisis.

    Science.gov (United States)

    Duggen, Svend; Hoernle, Kaj; van den Bogaard, Paul; Rüpke, Lars; Morgan, Jason Phipps

    2003-04-10

    The Messinian salinity crisis--the desiccation of the Mediterranean Sea between 5.96 and 5.33 million years (Myr) ago--was one of the most dramatic events on Earth during the Cenozoic era. It resulted from the closure of marine gateways between the Atlantic Ocean and the Mediterranean Sea, the causes of which remain enigmatic. Here we use the age and composition of volcanic rocks to reconstruct the geodynamic evolution of the westernmost Mediterranean from the Middle Miocene epoch to the Pleistocene epoch (about 12.1-0.65 Myr ago). Our data show that a marked shift in the geochemistry of mantle-derived volcanic rocks, reflecting a change from subduction-related to intraplate-type volcanism, occurred between 6.3 and 4.8 Myr ago, largely synchronous with the Messinian salinity crisis. Using a thermomechanical model, we show that westward roll back of subducted Tethys oceanic lithosphere and associated asthenospheric upwelling provides a plausible mechanism for producing the shift in magma chemistry and the necessary uplift (approximately 1 km) along the African and Iberian continental margins to close the Miocene marine gateways, thereby causing the Messinian salinity crisis. PMID:12686997

  9. Modelling saline intrusion for repository performance assessment

    International Nuclear Information System (INIS)

    UK Nirex Ltd are currently considering the possibility of disposal of radioactive waste by burial in deep underground repositories. The natural pathway for radionuclides from such a repository to return to Man's immediate environment (the biosphere) is via groundwater. Thus analyses of the groundwater flow in the neighbourhood of a possible repository, and consequent radionuclide transport form an important part of a performance assessment for a repository. Some of the areas in the UK that might be considered as possible locations for a repository are near the coast. If a repository is located in a coastal region seawater may intrude into the groundwater flow system. As seawater is denser than fresh water buoyancy forces acting on the intruding saline water may have significant effects on the groundwater flow system, and consequently on the time for radionuclides to return to the biosphere. Further, the chemistry of the repository near-field may be strongly influenced by the salinity of the groundwater. It is therefore important for Nirex to have a capability for reliably modelling saline intrusion to an appropriate degree of accuracy in order to make performance assessments for a repository in a coastal region. This report describes work undertaken in the Nirex Research programme to provide such a capability. (author)

  10. Incorporation of salinity in Water Availability Modeling

    Science.gov (United States)

    Wurbs, Ralph A.; Lee, Chihun

    2011-10-01

    SummaryNatural salt pollution from geologic formations in the upper watersheds of several large river basins in the Southwestern United States severely constrains the use of otherwise available major water supply sources. The Water Rights Analysis Package modeling system has been routinely applied in Texas since the late 1990s in regional and statewide planning studies and administration of the state's water rights permit system, but without consideration of water quality. The modeling system was recently expanded to incorporate salinity considerations in assessments of river/reservoir system capabilities for supplying water for environmental, municipal, agricultural, and industrial needs. Salinity loads and concentrations are tracked through systems of river reaches and reservoirs to develop concentration frequency statistics that augment flow frequency and water supply reliability metrics at pertinent locations for alternative water management strategies. Flexible generalized capabilities are developed for using limited observed salinity data to model highly variable concentrations imposed upon complex river regulation infrastructure and institutional water allocation/management practices.

  11. [Characteristics of soil salinity profiles and their electromagnetic response under various vegetation types in coastal saline area].

    Science.gov (United States)

    Yang, Jing-Song; Yao, Rong-Jiang; Zou, Ping; Liu, Guang-Ming

    2008-10-01

    Aiming at the intrinsic relationships between vegetation type and soil salinity in coastal saline area, and by using electromagnetic induction EM38 and field sampling method, the characteristics of soil salinity profiles under various vegetation types in typical coastal saline region of the Yellow River Delta were analyzed, and the electromagnetic response characters of the salinity profiles were compared. The results showed that across the study area, soil salinity exhibited the characteristics of top enrichment and strong spatial variation. The horizontal electromagnetic conductivity EM(h) responded well to soil salinity at upper layers, and the response of vertical electromagnetic conductivity EM(v) to soil salinity at deeper layers was superior to that of EM(h). Soil salinity profiles were classified into inverted, normal, and uniform types. The vegetation types of inverted salinity profiles were mainly bare land and Suaeda salsa, while those of normal and uniform salinity profiles were cotton and weed, respectively. The sequence of top enrichment intensity was bare land > S. salsa land > weed land > cotton land. With the change of vegetation type of cotton-weed-S. salsa-bare land, the EM(v)/EM(h) value of salinity profiles decreased gradually. Nonparametric test results showed that there was a significant correlation between vegetation type and electromagnetic response characters, and the distribution characters of EM(v)/EM(h) under various vegetation types varied significantly. PMID:19123343

  12. Effects of Decreasing Soil Water Content on Evaporation under Saline and Non-Saline Conditions

    Directory of Open Access Journals (Sweden)

    F. Konukcu

    2006-05-01

    Full Text Available Evaporation changes in mechanism and magnitude as the soil dries. Evaporation are closely related tothe soil moisture. Penman’s method is used most widely to define the upper boundary condition in computingevaporation from a relatively wet bare soil surface. It assumes saturated vapour pressure at the soil surfaceand calculates potential evaporation independent of the soil water content. It was modified by Staple (1974including in it the soil’s relative humidity of partially dried surface to predict evaporation from drying soils.The objective of this study was to investigate the rate of evaporation under aerodynamic (in door andaerodynamic + radiation (out door conditions for saline and non saline drying soil surface using Staplemodified Penman equation seeking for further improvements. Soil samples (clayey were first saturated withfresh and saline (16 dS/m water and then exposed to evaporation. Generally, the agreements betweensimulated and measured rates for out/indoor conditions were good (R2 = 0.90. However more deviationoccurred at the beginning and the final stage, attributable to the difference in soil surface and air temperature.While the model calculated roughly the same rates for saline and non-saline conditions, the effect of soiltexture is accounted by defining matric potential-water content and soil relative humidity-water contentrelationships.

  13. Effect of Initial Soluble Salt Composition of Saline Soil on Salinity Tolerance of Barley Plant

    Institute of Scientific and Technical Information of China (English)

    SHENQI-RONG; LIUZHAO-PU; 等

    1991-01-01

    A pot experiment was carried out on a marine saline soil to study the effect of initial soluble Na/Ca ratio of saline soil on the salinity tolerance of barley plant.The results showed that (1) the Na/Ca ratio affected significantly the dry weight of the plant at an earlier stage of growth,the critical values of initial Na/Ca ratio at which the plant could grow normally on soils containing salts of 2.5,3.5 and 4.5g kg-1 were 30,20 and 15,respectively;(2)smaller Na/Ca ratio resulted in a considerable decrease in Na accumulation but a great increase in K accumulation in the barley plant;and (3) the plasmallema of barley leaf were badly injured when the Na/Ca ratio was more than 30 and the increase of Na content of plant caused an exudation of K from the leaf cells.Some critical indexes were suggested for the cultivation of barley plant on marine saline soils and could be used as reference in the biological reclamation of marine saline soils.

  14. The effectiveness of dispersants under various temperature and salinity regimes

    Energy Technology Data Exchange (ETDEWEB)

    Fingas, M.; Fieldhouse, B.; Wang, Z. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Div; Environment Canada, Ottawa, ON (Canada). Environmental Technology Centre

    2005-07-01

    A series of tests were conducted to determine the effectiveness of dispersants in Arctic waters where salinity and temperature interactions play a critical role. In particular, Corexit 9500 was tested on Alaska North Slope oil at different temperatures and salinity using the ASTM standard test and variations of this test. Results were compared to the only historically reported test in which both temperature and salinity were changed over a range of values. This series of tests demonstrated that there is an interaction between salinity, temperature and dispersant effectiveness. It was shown that conventional and currently available dispersants are nearly ineffective at 0 salinity. Dispersant effectiveness peaks at 20 to 40 units of salinity, depending on the type of dispersant. Corexit is less sensitive to salinity, while Corexit 9527 is more sensitive to salinity. There is a smooth gradient of effectiveness with salinity both as the salinity rises to a peak point of effectiveness and as it exceeds this value. Results from the 2 field trials in fresh water suggest that laboratory tests correctly conclude that the effectiveness of dispersants is very low in freshwater. The study also examined several analytical factors such as the total petroleum hydrocarbon (TPH) versus relative petroleum hydrocarbon (RPH) methods, specific versus general calibration curves, and automatic versus manual baseline placement. The analytical variations of effectiveness by RPH or TPH methods do not affect the fundamental relationship between salinity and temperature. 6 refs., 6 tabs., 8 figs.

  15. Incorporating Sedimentological Observations, Hydrogeophysics and conceptual Knowledge to Constrain 3D Numerical Heterogeneity Models of Coarse Alluvial Systems

    Science.gov (United States)

    Huber, E.; Huggenberger, P.

    2012-12-01

    Accurate predictions on groundwater flow and transport behavior within fluvial and glaciofluvial sediments, but also interaction with surface water bodies, rely on knowledge of distributed aquifer properties. The complexity of the depositional and erosional processes in fluvial systems leads to highly heterogeneous distributions of hydrogeological parameters. The system dynamics, such as aggradation rates and channel mobility of alluvial systems; its influence on the preservation potential of the key depositional elements in the geological record; and its influence on the heterogeneity scales and the relevance for groundwater hydraulics is topic of the presentation. The aims of our work are to find a relation between surface morphological structures and the sedimentary structures in vertical profiles (i.e. gravel pits or GPR sections) and to derive rules for the interpretation of horizontal time-slices from 3D GPR data. Based on these data we set-up conceptual models of the structures of coarse alluvial systems at different scales which can be tested by stochastic methods. Relevant depositional elements and a hierarchy or genetic relationship of such elements will be defined based on the knowledge of depositional processes in alluvial systems inferred from: field observations after major flood events; 2D and 3D GPR data; and from existing data derived from laboratory flumes. Extensive geophysical field experiments within the Tagliamento alluvial system gave new insights to the sedimentary structures developing at high flows. Owing to the fact that rivers often destroy at least part of their bed during or shortly after large floods and subsequently rebuild, it is not easy to establish a simple relationship between surface morphology and the sedimentary structures found in vertical sections of many alluvial outcrops. According to these findings we suppose that surface or near-surface structures will not catch the essence of heterogeneity of alluvial aquifers

  16. Durum wheat seedlings in saline conditions: Salt spray versus root-zone salinity

    Science.gov (United States)

    Spanò, Carmelina; Bottega, Stefania

    2016-02-01

    Salinity is an increasingly serious problem with a strong negative impact on plant productivity. Though many studies have been made on salt stress induced by high NaCl concentrations in the root-zone, few data concern the response of plants to saline aerosol, one of the main constraints in coastal areas. In order to study more in depth wheat salinity tolerance and to evaluate damage and antioxidant response induced by various modes of salt application, seedlings of Triticum turgidum ssp. durum, cv. Cappelli were treated for 2 and 7 days with salt in the root-zone (0, 50 and 200 mM NaCl) or with salt spray (400 mM NaCl + 0 or 200 mM NaCl in the root-zone). Seedlings accumulated Na+ in their leaves and therefore part of their ability to tolerate high salinity seems to be due to Na+ leaf tissue tolerance. Durum wheat, confirmed as a partially tolerant plant, shows a higher damage under airborne salinity, when both an increase in TBA-reactive material (indicative of lipid peroxidation) and a decrease in root growth were recorded. A different antioxidant response was activated, depending on the type of salt supply. Salt treatment induced a depletion of the reducing power of both ascorbate and glutathione while the highest contents of proline were detected under salt spray conditions. In the short term catalase and ascorbate peroxidase co-operated with glutathione peroxidase in the scavenging of hydrogen peroxide, in particular in salt spray-treated plants. From our data, the durum wheat cultivar Cappelli seems to be sensitive to airborne salinity.

  17. 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.

  18. 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.

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

    Science.gov (United States)

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

    1994-01-01

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

  20. 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.

  1. Near-decadal changes in nitrate and pesticide concentrations in the South Platte River alluvial aquifer, 1993-2004

    Science.gov (United States)

    Paschke, S.S.; Schaffrath, K.R.; Mashbum, S.L.

    2008-01-01

    The lower South Platte River basin of Colorado and Nebraska is an area of intense agriculture supported by surface-water diversions from the river and ground-water pumping from a valley-fill alluvial aquifer. Two well networks consisting of 45 wells installed in the South Platte alluvial aquifer were sampled in the early 1990s and again in the early 2000s to examine near-decadal ground-water quality changes in irrigated agricultural areas. Ground-water age generally increases and dissolved-oxygen content decreases with distance along flow paths and with depdi below the water table, and denitrification is an important natural mitigation mechanism for nitrate in downgradient areas. Ground-water travel time from upland areas to the river ranges from 12 to 31 yr on the basis of apparent ground-water ages. Ground-water nitrate concentrations for agricultural land-use wells increased significantly for oxidized samples over the decade, and nitrogen isotope ratios for oxidized samples indicate synthetic fertilizer as the predominant nitrate source. Ground-water concentrations of atrazine, DEA, and prometon decreased significandy. The decrease in pesticide concentrations and a significant increase in the ratio of DEA to atrazine suggest decreases in pesticide concentrations are likely caused by local decreases in application rates and/or degradation processes and that atrazine degradation is promoted by oxidizing conditions. The difference between results for oxidizing and nitrate-reducing conditions indicates redox state is an important variable to consider when evaluating ground-water quality trends for redox-sensitive constituents such as nitrate and pesticides in the South Platte alluvial aquifer. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  2. 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.

  3. The timing of alluvial sedimentation and floodplain formation in the lowland humid tropics of Ghana, Sierra Leone and western Kalimantan (Indonesian Borneo)

    Science.gov (United States)

    Thorp, Martin; Thomas, Michael

    1992-04-01

    Temporal patterns in floodplain genesis and alluvial sedimentation in lowlands tropical rain forest zones of Ghana, Sierra Leone and western Kalimantan (Indonesian Borneo) based upon 14C age determinations are described. Alluvial low terraces or buried sediments in West Africa yielded ages of 36-21 ka. In west Kalimantan a widespread episode of alluviation has yielded dates of 54-51 ka. The 20-13 ka interval was characterised by channel incision with valley floor erosion and neither region records sedimentation. Holocene alluvial sedimentation and floodplain construction in West Africa occurred during two temporal intervals: 10-7 ka and 4 ka to present and in western Kalimantan in response to early Holocene sea level rise followed by late Holocene regression and coastal outgrowth. The clustering of 14C dates closely corresponds to regional lake level fluctuations and vegetational changes and to global indications of climatic change. We propose that periods of more frequent episodes of accelerated floodplain erosion and reconstitution, channel morpho-sedimentary activity and alluvial accumulation (1) are responses to interstadial and interglacial periods of higher precipitation following intervening periods of cooler and drier conditions; and (2) may be synchronous during the last 60 ka throughout the African and Asian inner humid lowland tropics.

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

    International Nuclear Information System (INIS)

    Alluvial soils are reservoirs of metal contaminants such as Pb that originate from many different sources and are integrated temporally and spatially through erosional and depositional processes. In this study the source, lability and solubility of Pb were examined in a range of alluvial soils from the middle and lower River Trent and its tributary the River Dove using Pb isotope apportionment and isotopic dilution. All samples were collected within 10 m of the river bank to represent the soil that is most likely to be remobilised during bank erosion. Paired samples were taken from the topsoil (0–15 cm) and subsoil (35–50 cm) to assess differences with depth. Lead concentrations in soil ranged from 43 to 1282 mg/kg. The lability of soil Pb varied between 9 and 56% of total metal concentration whilst Pb concentrations in pore water varied between 0.2 and 6.5 μg/L. There was little difference in the % Pb lability between paired top and sub soils, possibly because soil characteristics such as pH, iron oxides and clay content were generally similar; a result of the recycling of eroded and deposited soils within the river system. Soil pH was found to be negatively correlated with % Pb lability. Source apportionment using 206Pb/207Pb and 208Pb/207Pb ratios showed that the isotopic ratios of Pb in the total, labile and solution pools fitted along a mixing line between Broken Hill Type (‘BHT’) Pb, used as an additive in UK petrol, and the local coal/Southern Pennine ore Pb. Various anomalies were found in the Pb isotopes of the bankside alluvial soils which were explained by point source pollution. Statistically significant differences were found between (i) the isotopic composition of Pb in the total soil pool and the labile/solution pools and (ii) the isotopic composition of Pb in the labile and solution pools, suggesting an enrichment of recent non-Pennine sources of Pb entering the soils in the labile and solution pools. -- Highlights: ► The labile pool of

  5. 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

  6. 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...

  7. 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

  8. Salinity trends in the Ebro River (Spain)

    Science.gov (United States)

    Lorenzo-Gonzalez, M.° Angeles; Isidoro, Daniel; Quilez, Dolores

    2016-04-01

    In the Ebro River Basin (Spain), the increase in water diversion for irrigation (following the increase in irrigated area) and the recovery of natural vegetation in the upper reaches, along with climate change have induced changes in the river flow and its associated salt loads. This study was supported by the Ebro River Basin Administration (CHE) and aimed to establish the trends in the salt concentrations and loads of the Ebro River at Tortosa (no 027, the extreme downstream gauging station). The CHE databases from 1972-73 to 2011-12, including mean monthly flows (Q) and concentration readings (electrical conductivity converted to total dissolved solids -TDS- by regression) from monthly grab samples, have been used. The trends were established by (i) harmonic regression analysis; (ii) linear regression by month; and (iii) the non-parametric Mann-Kendall method. Additionally, (iv) the regressions of TDS on Q in the current and previous months were established, allowing for analyzing separately the trends in TDS linked to- (TDSq) and independent of- (TDSaj) the observed changes in flow. In all cases, the trends were analyzed for different periods within the full span 1973-2012 (1973 to 2012, 1981 to 2012, 1990-2012 and 2001-2012), trying to account for periods with sensibly similar patterns of land use change. An increase in TDS was found for all the periods analyzed that was lower as shorter periods were used, suggesting that lower salinity changes might be taking place in the last years, possibly due to the reduction in the rate of irrigation development and to the on-going irrigation modernization process. The higher seasonal TDS increases were found in autumn and winter months and the increase in TDS was linked both to intrinsic changes in salinity (TDSaj) and to the observed decrease in flow (TDSq). On the other hand, the salt loads decreased, especially in autumn, as a result of the observed flow decrease. These results are based on the observed evolution of

  9. The Aquarius Salinity Retrieval Algorithm: Early Results

    Science.gov (United States)

    Meissner, Thomas; Wentz, Frank J.; Lagerloef, Gary; LeVine, David

    2012-01-01

    The Aquarius L-band radiometer/scatterometer system is designed to provide monthly salinity maps at 150 km spatial scale to a 0.2 psu accuracy. The sensor was launched on June 10, 2011, aboard the Argentine CONAE SAC-D spacecraft. The L-band radiometers and the scatterometer have been taking science data observations since August 25, 2011. The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to O2, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind. This is based on the radar backscatter measurements by the scatterometer. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water and an auxiliary field for the sea surface temperature. In the current processing (as of writing this abstract) only v-pol TB are used for this last process and NCEP winds are used for the roughness correction. Before the salinity algorithm can be operationally implemented and its accuracy assessed by comparing versus in situ measurements, an extensive calibration and validation

  10. 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

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

    Directory of Open Access Journals (Sweden)

    Rudy Erwiyono

    2005-08-01

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

  12. 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

  13. Interactions Between Riparian Evapotranspiration and Streambed Infiltration As Expressed in Shallow Alluvial Aquifer Levels

    Science.gov (United States)

    Cadol, D. D.; Wine, M.

    2014-12-01

    Rivers in semiarid regions are typically 'ribbons of green' through otherwise sparsely vegetated landscapes. As these rivers convey water from sometimes distant sources they lose water to shallow riparian aquifers which frequently support a rich phreatophytic vegetation community. In order to monitor the interactions between streamflow, alluvial aquifers, and riparian vegetation, water levels in 3 monitoring wells near the Rio Grande at Escondida, NM, were recorded beginning in May 2013. Two summers of data reveal a strong diel signal in the water table levels, indicating a clear interaction between vegetation transpiration and aquifer storage. Likewise, comparison with stage data from a USGS gage 25 m upstream of the well transect shows a clear aquifer recharge signal. Prior work at this site during fall 2005 has suggested that streambed infiltration rates vary in a daily cycle, possibly due to temperature controls on water viscosity. In order to evaluate the relative roles of the two potential cycles we also monitored near-bed hydraulic gradients and remotely sensed vegetation indices (VIs). To measure hydraulic gradient we installed an additional piezometer in the bed of the river, screened 3 feet below the sediment surface, and began logging head in December 2013. The Enhanced Vegetation Index (EVI) was calculated from Landsat scenes that had clear views of the nearby riparian forest during the monitoring period. Preliminary results indicate that periods with high EVI and high evaporative demand (as estimated from a nearby weather station) correlate with greater water level cycle amplitude and, presumably, vegetation-aquifer interaction. We did not observe any diel signals in the water table data during periods with low leaf cover, casting some doubt on the importance of the previously reported streambed infiltration rate driven cyclicity, however analysis of the near-bed hydraulic gradient data is ongoing and will be compared with residuals of the EVI

  14. Ocean Salinity and the Global Water Cycle

    OpenAIRE

    Paul Durack

    2015-01-01

    Alterations to the global water cycle are of concern as Earth’s climate changes. Although policymakers are mainly interested in changes to terrestrial rainfall—where, when, and how much it’s going to rain—the largest component of the global water cycle operates over the ocean where nearly all of Earth’s free water resides. Approximately 80% of Earth’s surface freshwater fluxes occur over the ocean; its surface salinity responds to changing evaporation and precipitation patterns by displaying ...

  15. Saline dust storms and their ecological impacts in arid regions

    Institute of Scientific and Technical Information of China (English)

    Jilili; Abuduwaili

    2010-01-01

    In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In this study,saline dust storms are reviewed systematically from the aspects of con-cept,general characteristics,conditions of occurrence,distribution and ecological impact.Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions;large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence;there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion;and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions.An under-standing of saline dust storms is important to guide disaster prevention and ecological rehabilitation.

  16. Effects of Soil Salinity on Sucrose Metabolism in Cotton Fiber

    Science.gov (United States)

    Liu, Jingran; Luo, Junyu; Zhao, Xinhua; Dong, Helin; Ma, Yan; Sui, Ning; Zhou, Zhiguo; Meng, Yali

    2016-01-01

    Cotton (Gosspium hirsutum L.) is classified as a salt tolerant crop. However, its yield and fiber quality are negatively affected by soil salinity. Studies on the enzymatic differences in sucrose metabolism under different soil salinity levels are lacking. Therefore, field experiments, using two cotton cultivars, CCRI-79 (salt-tolerant) and Simian 3 (salt-sensitive), were conducted in 2013 and 2014 at three different salinity levels (1.15 dS m-1 [low soil salinity], 6.00 dS m-1 [medium soil salinity], and 11.46 dS m-1 [high soil salinity]). The objective was to elucidate the effects of soil salinity on sucrose content and the activity of key enzymes that are related to sucrose metabolism in cotton fiber. Results showed that as the soil salinity increased, cellulose content, sucrose content, and sucrose transformation rate declined; the decreases in cellulose content and sucrose transformation rate caused by the increase in soil salinity were more in Simian 3 than those in CCRI-79. With increase in soil salinity, activities of sucrose metabolism enzymes sucrose phophate synthase (SPS), acidic invertase, and alkaline invertase were decreased, whereas sucrose synthase (SuSy) activity increased. However, the changes displayed in the SuSy and SPS activities in response to increase in soil salinity were different and the differences were large between the two cotton cultivars. These results illustrated that suppressed cellulose synthesis and sucrose metabolism under high soil salinity were mainly due to the change in SPS, SuSy, and invertase activities, and the difference in cellulose synthesis and sucrose metabolism in fiber for the two cotton cultivars in response to soil salinity was determined mainly by both SuSy and SPS activities. PMID:27227773

  17. Effect of Two Halophyte Plants Irrigated with Saline Water on Soil Salinization under Different Soil Type

    International Nuclear Information System (INIS)

    A lysimeter experiment was conducted to evaluate the impact of saline water irrigation at three levels namely, fresh water (0.3), 4 and 8 dS/m on salt accumulation and its effect on different soil types. The tested halophyte plants were Kallar grass and Atriplex (Salt bush). The tested soil types were sandy, calcareous and clayey soils. Irrigating the soil with saline water (either 4 or 8 dS/m) resulted in increasing salinity levels in soil profile with different orders of magnitude, depending on the soil type layer and the cultivated plant. Kallar grass seems limit the accumulation of salts in soil profile, compared to Atriplex at any tested soil. This may be attributed to its root effect on soil profile such as dispersed soil matrix and improved soil structure, which provide channels for solute movement through the profile under halophyte cultivation. Calculating the SAR average values for each irrigation treatment (18 values) showed significant increase in soil SAR values, especially under Kallar grass compared to Atriplex. The highest SAR values were observed in the case of clayey soil. However, the relevant SAR values under Atriplex cultivation were always lower. Values for SAR were always higher in the saline clayey > calcareous > sandy soils

  18. Salinity dominance on the Indian Ocean Eastern Gyral current

    Science.gov (United States)

    Menezes, Viviane V.; Phillips, Helen E.; Schiller, Andreas; Domingues, Catia M.; Bindoff, Nathaniel L.

    2013-11-01

    This study demonstrates the importance of salinity gradients to the formation of the Eastern Gyral Current (EGC) in the South Indian Ocean. The EGC flows eastward near 15∘S, opposite to the direction predicted by classical theories of wind-driven circulation and is a source of water for the Leeuwin Current. In the upper ocean, a strong salinity front exists between fresh water from the Indonesian Throughflow (ITF) in the South Equatorial Current (SEC) and salty subtropical waters. In that region, salinity overwhelms the temperature contribution to density gradients, generating eastward geostrophic shear and establishing the EGC. Without the salinity front the EGC cannot be maintained: If the salinity contribution is neglected in the calculation of geostrophic currents, the EGC vanishes. Our observational analysis associated with the fact that both Sverdrup and Ekman theories produce westward flows in the region strongly supports the idea that the EGC is a salinity-driven current.

  19. Influence of salinity on petroleum accommodation by dispersants

    Energy Technology Data Exchange (ETDEWEB)

    Blondina, G.J. [California Department of Fish and Game, Office of Spill Prevention and Response, Santa Cruz, CA (United States); Singer, M.M.; Lee, I.; Ouano, M.T.; Hodgins, M.; Tjeerdema, R.S. [California Univ., Dept. of Chemistry and Biochemistry, Santa Cruz, CA (United States); Sowby, M.L. [California Department of Fish and Game, Office of Spill Prevention and Response, Sacramento, CA (United States)

    1999-07-01

    The effect of receiving water salinity on the effectiveness of two oil dispersants, Corexits 9527 and 9500, was investigated using a recently implemented modified version of the Swirling Flask efficacy test. The dispersants were tested with ten different oils, representing a wide range of physical-chemical properties. Test salinities ranged from 0 to 35 ppt, with temperature held constant at 15degC. Results showed Corexit 9500 to be generally more effective on most of the dispersible oils at most salinities, but performance of both products was significantly affected by salinity. Both dispersants performed best at salinities above 25 ppt, with Corexit 9500 maintaining its effectiveness over a fairly wide range of salinities. Correlations between dispersant effectiveness and various oil physical/chemical properties were highly variable. (Author)

  20. 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.

  1. Oil pollutants in alluvial sediments – influence of the intensity of contact with ground waters on the effect of microorganisms

    Directory of Open Access Journals (Sweden)

    H. WEHNER

    2003-03-01

    Full Text Available The influence of the intensity of interaction between oil pollutants and ground waters in alluvial sediments on the effect of microbial activity was investigated in this work. The study was based on a comparison of detailed analyses of two fractions of an oil pollutant originating from a Danube alluvial formation near the Pancevo Oil Refinery: fraction 1, separated from the aqueous layer by decantation, presumed to have been in less intensive interaction with water, and fraction 2, isolated from the aqueous emulsion by extraction with chloroform, presumed to have been in stronger interaction with water. Both fractions were shown to originate from the same type of oil pollutant. Nevertheless, significant compositional differences between the two fractions were observed. A significantly pronounced domination of even carbon number homologues of C18–C24 n-alkanes in fraction 2, atypical for crude oil pollutants, compared to the corresponding distribution observed in fraction 1, suggested a more intense activity, i.e., a much better effect of microorganisms in direct contact with the oil pollutant within the aqueous environment. The identification of even carbon number C14–C18 n-alcohols and C14–C18 fatty acids, as well as cholesterol, in fraction 2, suggested that microorganisms of the algal type in non-photosynthetic conditions were most probably responsible for the mentioned microbial processes.

  2. 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.

  3. Characteristics of the gravel size and potassium in the Ejin Alluvial Fan from remote sensing images and stratigraphic section

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. Impact of river bank filtration on alluvial groundwater quality: A case study of the Velika Morava River in central Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Branislav Z.

    2015-01-01

    Full Text Available Alluvial aquifers are preferred sites for drinking water production. Riverbed sediments and saturated alluvial sediments have great potential for groundwater purification which is essential for preserving the stability of the groundwater quality. Conducted research in the area of groundwater source Brzan in central Serbia showed that intergranular aquifer has potential not only to purify polluted surface water but also to enrich water quality. Main aquifer recharge is infiltration of surface water from the Velika Morava River. The quality of surface water is very variable, especially for some components such as turbidity, conductivity, KMnO4 consumption, and iron, chloride and nitrates content. On the other hand, the quality of groundwater is characterised with minimal oscillation particularly regarding mentioned components. Based on numerous results on surface and groundwater quality we can conclude that water from the groundwater source Brzan is with good quality and can be used for drinking consumption with minimal treatment despite the fact that aquifer is in strong hydraulic connection with the Velika Morava River. Improvement of water quality is result manly of water filtration through river bad sediments and aquifer body. [Projekat Ministarstva nauke Republike Srbije, br. 176022 i br. 43004

  6. 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.

  7. 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.

  8. Salinity influences the biochemical response of Crassostrea angulata to Arsenic.

    Science.gov (United States)

    Moreira, Anthony; Figueira, Etelvina; Soares, Amadeu M V M; Freitas, Rosa

    2016-07-01

    The increasing rate of occurrence and persistence of climatic events causing salinity shifts, in combination with contamination, may further challenge organisms response to environmental stress. Hence, we studied the effects of different salinity levels (10, 20, 30 and 40) on the response of the oyster Crassostrea angulata to Arsenic (As) exposure (4 mg L(-1)). Total As, Na(+) and K(+) concentrations in oyster tissues were determined. Biochemical analysis were performed to assess osmotic regulation (CA), metabolism (ETS), enzymatic (SOD, CAT and GSTs) and non-enzymatic (GSH/GSSG and LPO) markers of oxidative stress. Results obtained showed significantly higher metabolic activities in oysters maintained in low salinity (10) exposure, coupled with higher As accumulation, as well as higher SOD and CAT activities, compared to higher salinities (30 and 40). GSTs activity and LPO levels were higher in oysters exposed to As at salinities 20, 30 and 40, compared to the same conditions without As. From our findings we concluded that the response of C. angulata to As is influenced by salinity. At the lowest salinity (10) oysters accumulated higher As concentrations, here attributed to higher metabolic rate involved in physiological osmoregulation, also stimulating antioxidant related enzymes activity (SOD and CAT) and thus preventing increased LPO (higher ETS activity also observed without As). On the contrary, at salinities 30 and 40 with As, antioxidant SOD and CAT were inhibited, enabling for LPO generation. Given our results, the effects of As on the oysters antioxidant capacity appears to be more deleterious under higher salinities (20, 30 and 40), comparing to salinity 10. The differentiated responses demonstrated in the present study in C. angulata oysters exposed to As under different salinities, bring new insights on the mechanisms of environmental adaptability of this species, namely to salinity shifts, and the interactions between such alterations and As

  9. Desalination leading to Salinity Variations in Kuwait Marine Waters

    OpenAIRE

    Ahmad E. Al-Dousari

    2009-01-01

    Problem statements: The salinity of seawater is a critical issue for desalination process. Approach: The salinity changes in the coastal waters of Kuwait due to large scale power and desalination activity were evaluated. Results: Systematic sampling campaigns were planned to cover the uptake and outfall of the desalination plant spreading evenly the sampling points to cover the freshwater input zone of Arabian Gulf in north. The salinity observations are critical both for the desalination pro...

  10. Three types of gradients in the saline ecosystem

    OpenAIRE

    Piernik, Agnieszka

    2003-01-01

    The aim of this study was to combine saline ecosystem structure and function by three aspects of the gradient concept: spatial, temporal and functional. The saline meadow was investigated in the vicinity of soda factory in Janikowo in the Kujawy region, central Poland. Three vegetation zones in the salinity gradient were distinguished on the meadow: the Sa/icornia europaea zone, the Puccinellia distans zone and the Elymus repens zone. The results demonstrated that taking into account spat...

  11. 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

  12. 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

  13. 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,...

  14. 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

  15. A comparison of classical and radio isotope methods in the determination of safe yield in the Sabi alluvial plain in Zimbabwe

    International Nuclear Information System (INIS)

    The Sabi Valley alluvial plain is the largest tract of alluvium in Zimbabwe. The groundwater hydrology of the alluvial plain was studied by three independent methods: the classical approach of potentiometric surface construction and pump test analyses; the use of in-borehole velocity and direction measurements with artificial radioactive isotopes applied to the point dilution technique; and a natural and thermonuclear tritium survey. The three methods of approach produce remarkably close values for the groundwater throughflow within the plain. A safe yield figure of 2.5 cubic metres/sec is currently used with confidence for the groundwater reservoir as a result of this study

  16. Ra-226 and Rn-222 in saline water compartments of the Aral Sea region

    International Nuclear Information System (INIS)

    radionuclide using an ICP sector field mass spectrometer. The 226Ra concentration of 17 unconfined groundwater samples ranged between 0.2 and 5 ppq, and that of 28 artesian waters between <0.2 and 13 ppq. The ICP-MS results conformed satisfactorily to analytical results based on γ-measurements of the 222Rn ingrowth after purging and trapping on super-cooled charcoal. The 226Ra concentrations were positively correlated with the salinity and the dissolved NaCl concentrations. The occurrence of unusually high 226Ra activities is explained by radium release from adsorption sites with increasing salinity. The inferred spatial variability of 222Rn in the Aral Sea and of 222Rn and 226Ra in the groundwater of the Amu Darya Delta is discussed in the context of our own previous hydrochemical studies in the study sites. Relatively low 222Rn activities in the unconfined GW (1–9.5 Bq/l) indicate the alluvial sediments hosting the GW to be a low-238U(226Ra) substrate. Positive correlations between U and 226Ra, and U and 222Rn are likely related to locally deposited Fe(Mn)OOH precipitates. The 222Rn activity of the GW, however, distinctly exceeds the 222Rn concentration in the Aral Sea (10 mBq/l), in principle, making 222Rn a sensitive tracer for the inflow of GW. The high water volume of the Large Aral Sea and wind induced mixing of its water body, however, hamper the detection of local groundwater inflow

  17. Differential Expression of Salinity Resistance Gene on Cotton

    Institute of Scientific and Technical Information of China (English)

    YE Wu-wei; YU Shu-xun

    2008-01-01

    @@ Salinity resistance and differential gene expression associated with salinity in cotton germplasm were studied,because of the large scale area of salinity in China,and its significant negative effects on the cotton production.The salinityresisted genes and their differential expression were studied under the stress of NaCI on cotton.There were found,under the NaCI stress,1644 genes differentially expressed from the salinity-sensitive cotton and only 817 genes differentially expressed from the salinityresisted cotton.

  18. High-resolution and compact refractometer for salinity measurements

    International Nuclear Information System (INIS)

    A new compact optical refractometer is presented to improve the measurement of the refractive index of seawater. These measurements are useful in oceanography to calculate density and salinity of oceans from empirical relations. This refractometer shows a lower temperature dependence and obtains a better absolute accuracy on salinity compared to the conductivity sensors which are used nowadays to assess seawater salinity. Tests and calibrations have been made in a temperature-stabilized seawater tank. They show that the prototype is capable of measuring seawater refractive index with a resolution of about ±4 × 10−7, equivalent to a salinity resolution of ±2 × 10−3 g kg−1

  19. Phenanthrene partitioning in sediment-surfactant-fresh/saline water systems

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the influence of salinity on the effectiveness of surfactants in the remediation of sediments contaminated with phenanthrene (PHE). This is an example of a more general application of surfactants in removing hydrophobic organic compounds (HOCs) from contaminated soil/sediment in saline environments via in-situ enhanced sorption or ex-situ soil washing. Salinity effects on surfactant micelle formation and PHE partitioning into solution surfactant micelles and sorbed surfactant were investigated. The critical micelle concentration of surfactants decreased, and PHE partition between surfactant micelles and water increased with increasing salinity. Carbon-normalized partition coefficients (Kss) of PHE onto the sorbed cationic surfactant increased significantly with increasing salinity, which illustrates a more pronounced immobilization of PHE by cationic surfactant in a saline system. Reduction of PHE sorption by anionic surfactant was more pronounced in the saline system, indicating that the anionic surfactant has a higher soil washing effectiveness in saline systems. - The effectiveness of surfactant-enhanced remediation technology was promoted when applying it in estuarine environment with a higher salinity.

  20. Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    Directory of Open Access Journals (Sweden)

    D. G. Wright

    2010-08-01

    Full Text Available Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models.

    First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies.

    Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it