WorldWideScience

Sample records for sandy loam silty

  1. Influence of crop residues on trifluralin mineralization in a silty clay loam soil.

    Science.gov (United States)

    Farenhorst, Annemieke

    2007-01-01

    Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day(-1) in soil with 16% A to 2.89E-02 day(-1) in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.

  2. Effect of biochar amendment on nitrate retention in a silty clay loam soil

    Directory of Open Access Journals (Sweden)

    Angela Libutti

    2016-08-01

    Full Text Available Biochar incorporation into agricultural soils has been proposed as a strategy to decrease nutrient leaching. The present study was designed to assess the effect of biochar on nitrate retention in a silty clay loam soil. Biochar obtained from the pyrogasification of fir wood chips was applied to soil and tested in a range of laboratory sorption experiments. Four soil treatments were considered: soil only (control, soil with 2, 4 and 8% of biochar by mass. The Freundlich sorption isotherm model was used to fit the adsorbed amount of nitrate in the soil-biochar mixtures. The model performed very well in interpreting the experimental data according to a general linear regression (analysis of co-variance statistical approach. Nitrate retention in the soilbiochar mixtures was always higher than control, regardless the NO3 – concentration in the range of 0-400 mg L–1. Different sorption capacities and intensities were detected depending on the biochar application rate. The highest adsorption capacity was observed in the soils added with 2 and 4% of biochar, respectively. From the results obtained is possible to infer that nitrate retention is higher at lower biochar addition rate to soil (2 and 4% and at lower nitrate concentration in the soil water solution. These preliminary laboratory results suggest that biochar addition to a typical Mediterranean agricultural soil could be an effective management option to mitigate nitrate leaching.

  3. IMPACT OF THE REPEATED TRACTOR PASSES ON SOME PHYSICAL PROPERTIES OF SILTY LOAM SOIL

    Directory of Open Access Journals (Sweden)

    Dubravko Filipović

    2011-12-01

    Full Text Available The aim of this paper was to quantify soil compaction induced by tractor traffic on untilled wet silty loam soil (Mollic Fluvisol. Changes in penetration resistance, bulk density and total porosity were measured for detecting the soil compaction. Treatments include ten passes of a four-wheel drive tractor with the engine power of 54.0 kW and weight of 3560 kg (1580 kg on the front axle and 1980 kg on the rear axle, 2.41 m distance between axles. The tyres on the tractor were cross-ply, front 11.2-24 and rear 16.9-30, with the inflation pressure of 160 kPa and 100 kPa, respectively. The speed of tractor during passes over experimental plots was 5.0 km h-1. In comparison to control, each tractor pass induced an increase in soil penetration resistance at all depths, and the average increment ratios, determined as the average of all layers, were 9.8, 18.5 and 26.1% after one, five and ten passes, respectively. The bulk density also increased with number of tractor passes, but with less percentage increasing. The increment ratios comparison to the control were 3.6, 9.5 and 12.9% after one, five and ten passes, respectively. The total porosity decreased with the number of passes, and the decrement ratios were 4.5, 16.5 and 20.8% after one, five and ten passes, respectively.

  4. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

    Directory of Open Access Journals (Sweden)

    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  5. Conceptual Model for Flow and Transport through Unsaturated Silty Loams and Sands in North Mississippi

    Science.gov (United States)

    Coleman, S. H.; Corley, D. S.; van Volkenburg, G. J.; Wildman, J. C.; Holt, R. M.

    2008-05-01

    We conducted a five-day ponded infiltration test at the University of Mississippi (UM) Soil Moisture Observatory (SMO). The 5 acre SMO is located in a former agricultural field at the UM Field Station, a 740 acre tract of land with restricted access located 11 miles from the UM campus in Oxford, Mississippi. At the infiltration site, the near surface soils consist of about infiltration test, the soil surface was leveled and a 2.0 m diameter infiltration ring was installed. Six neutron access tubes were installed to a depth of 2.5 m around the infiltration ring. A constant ponding depth of 13 cm was maintained throughout the duration of the experiment. Blue dye was added to the water to enable mapping of infiltration paths. During the experiment, moisture content profiles were periodically measured at each neutron access tube. Neutron probe data suggested that infiltration was dominated by capillary forces. However, later mapping of a trench through the infiltration site revealed that infiltration in the upper silt loam was dominated by macropore flow along roots and microfractures in the soil. In the sand, gravity driven fingers formed below the root-zone, where deep roots focused flow.

  6. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    for each rotation: mouldboard ploughing to a depth of 20 cm (MP); harrowing to a depth of 8–10 cm (H); and direct drilling (D) at two experimental sites with a sandy loam soil and different water budgets in Denmark. The Muencheberg soil quality rating (M-SQR) method and simpler soil quality indices (i...

  7. Effect of Application of Increasing Concentrations of Contaminated Water on the Different Fractions of Cu and Co in Sandy Loam and Clay Loam Soils

    Directory of Open Access Journals (Sweden)

    John Volk

    2016-12-01

    Full Text Available This study aimed to establish the fate of copper (Cu and cobalt (Co in sandy loam and clay loam soils that had been irrigated with increasing concentrations of contaminated water. A sequential extraction procedure was used to determine the fractions of Cu and Co in these soils. The concentration of bioavailable Cu and Co on clay loam was 1.7 times that of sandy loam soil. Cu on sandy loam soil was largely in the organic > residual > exchangeable > water-soluble > carbonate fractions, whereas on clay loam soil the element was largely in organic > exchangeable > residual > carbonate > water-soluble fractions. Co was largely observed in the exchangeable, water-soluble, and carbonate fractions, but with no particular trend observed in both soil types. When crops are grown on sandy soils that have a low capacity to hold heavy metals, the resulting effect would be high uptake of the heavy metals in crop plants. Because the predominant forms of Cu and Co vary in soils, it is expected that the metals will behave differently in the soils.

  8. [Effects of Different Residue Part Inputs of Corn Straws on CO2 Efflux and Microbial Biomass in Clay Loam and Sandy Loam Black Soils].

    Science.gov (United States)

    Liu, Si-yi; Liang, Ai-zhen; Yang, Xue-ming; Zhang, Xiao-ping; Jia, Shu-xia; Chen, Xue-wen; Zhang, Shi-xiu; Sun, Bing-jie; Chen, Sheng-long

    2015-07-01

    The decomposed rate of crop residues is a major determinant for carbon balance and nutrient cycling in agroecosystem. In this study, a constant temperature incubation study was conducted to evaluate CO2 emission and microbial biomass based on four different parts of corn straw (roots, lower stem, upper stem and leaves) and two soils with different textures (sandy loam and clay loam) from the black soil region. The relationships between soil CO2 emission, microbial biomass and the ratio of carbon (C) to nitrogen (N) and lignin of corn residues were analyzed by the linear regression. Results showed that the production of CO2 was increased with the addition of different parts of corn straw to soil, with the value of priming effect (PE) ranged from 215. 53 µmol . g-1 to 335. 17 µmol . g -1. Except for corn leaves, the cumulative CO2 production and PE of clay loam soil were significantly higher than those in sandy loam soil. The correlation of PE with lignin/N was obviously more significant than that with lignin concentration, nitrogen concentration and C/N of corn residue. The addition of corn straw to soil increased the contents of MBC and MBN and decreased MBC/MBN, which suggested that more nitrogen rather than carbon was conserved in microbial community. The augmenter of microbial biomass in sandy loam soil was greater than that in clay loam soil, but the total dissolved nitrogen was lower. Our results indicated that the differences in CO2 emission with the addition of residues to soils were primarily ascribe to the different lignin/N ratio in different corn parts; and the corn residues added into the sandy loam soil could enhance carbon sequestration, microbial biomass and nitrogen holding ability relative to clay loam soil.

  9. Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil

    Science.gov (United States)

    2015-04-01

    FOLSOMIA CANDIDA IN A NATURAL SANDY LOAM SOIL ECBC-TR-1272 Carlton T. Phillips Ronald T. Checkai Roman G. Kuperman Michael Simini Jan E...SUBTITLE Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil 5a. CONTRACT NUMBER 5b...2,4-dinitrotoluene (2,4-DNT) Folsomia candida octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) 2,6-dinitrotoluene

  10. Effect of biochar on aerobic processes, enzyme activity, and crop yields in two sandy loam soils

    DEFF Research Database (Denmark)

    Sun, Zhencai; Bruun, Esben; Arthur, Emmanuel

    2014-01-01

    of wood-based biochar on soil respiration, water contents, potential ammonia oxidation (PAO), arylsulfatase activity (ASA), and crop yields at two temperate sandy loam soils under realistic field conditions. In situ soil respiration, PAO, and ASA were not significantly different in quadruplicate field......, it was found that soil pH, rather than biochar rates, was a driving environmental variable. For ASA, the methodological approach was challenged by product sorption, but results did not suggest that biochar significantly stimulated the enzyme activity. Crop yields of maize in field experiments with 10–100 Mg...

  11. Assessment of Fate of Thiodicarb Pesticide in Sandy Clay Loam Soil

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    M. A. Bajeer

    2015-06-01

    Full Text Available In present study the fate of thiodicarb pesticide in sandy clay loam soil was investigated through its adsorption and leaching using HPLC. Experimental results revealed that thiodicarb follows first order kinetic with rate constant value of 0.711 h-1 and equilibrium study showed that Freundlich model was best fitted with multilayer adsorption capacity 3.749 mol/g and adsorption intensity 1.009. Therefore, adsorption of thiodicarb was multilayer, reversible and non-ideal. Leaching study has indicated intermediate mobility of thiodicarb with water due to its solubility, while field study showed the non-leacher nature. However both adsorption and leaching were heavily affected by soil characteristics. As the soil taken was sandy clay loam hence due to clay texture adsorption was higher because of vacant sites existing and greater surface area. For this the pesticide has remained adsorbed in above 20 cm soil layer as clearly seen from field study, minor amount was recorded in third layer of soil having 21-30 cm depth. The leached amount of thiodicarb in first and last part of water was 1.075 and 0.003 ng/µl. The general trend observed for adsorption in column and field soil was decreased downwards from 2.027 to 0.618 and 5.079 to 0.009 ng/µl.

  12. Effect of Corn Residue Biochar on the Hydraulic Properties of Sandy Loam Soil

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    Avanthi Deshani Igalavithana

    2017-02-01

    Full Text Available Biochar has an ability to alter the biological, chemical, and physical properties of soil due to its physicochemical properties such as surface area, porosity, nutrient retention ability, available nutrient contents, aromaticity, etc. The present study was designed to evaluate the impact of physical properties and application rate of biochar on the hydraulic properties of a sandy loam soil in the short term. Biochar was produced at 500 °C from dried corn residue (BC500. The BC500 was incorporated at the rates of 0, 2.5%, 5.0%, 7.5%, and 10% (w·w−1 into the sandy loam soil and filled up to a height of 4 cm, in cores having 5 cm diameter and height. Each treatment was performed in triplicate and equilibrated for 30 days. Then saturated hydraulic conductivity (Ksat, water holding capacity (WHC, and bulk density were determined in each sample after four days of saturation at room temperature in a water bath. The BC500 particle size distribution, pores, and surface functional groups were assessed. The Ksat exhibited a highly significant exponential reduction from 0% to 7.5% of BC500 application and approached an asymptote at 10% BC500. Bulk density showed a significant negative correlation to biochar application rate. The WHC and BC500 application rate illustrated a strong positive relationship. Biochar surface was free from hydrophobic functional groups. The addition of BC500 has a positive influence on soil hydraulic properties, primarily due to the increased soil porosity. The BC500 is composed of a microporous structure and hydrophilic surface that retain water in sandy textured soils. The application of BC500 would be a wise investment to maximize the water use efficiency in soils for agricultural production.

  13. USE OF THE “ROTHC” MODEL TO SIMULATE SOIL ORGANIC CARBON DYNAMICS ON A SILTY-LOAM INCEPTISOL IN NORTHERN ITALY UNDER DIFFERENT FERTILIZATION PRACTICES

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    Rosa Francaviglia

    2014-01-01

    Full Text Available We evaluated the efficiency of the RothC model to simulate Soil Organic Carbon (SOC dynamics after 12 years of organic and mineral fertilization practices in a study area located in northern Italy, on a silty-loam Inceptisol with a rotation including tomato, maize and alfalfa. The model performance was assessed by RMSE and EF coefficients. RothC simulated well observed SOC decreases in 71 samples (RMSE=7.42; EF=0.79, while performed with less accuracy when considering all samples (96 samples; RMSE=12.37; EF=0.58, due to the fact that the model failed in case of measured SOC increases (25 samples; RMSE=20.77; EF=-0.038. The model was used to forecast the SOC dynamics over a 50 year period under the same pedoclimatic conditions. Only clay contents >15% allowed to predict increasing levels of SOC respect to the starting values.

  14. Pore structure characteristics after two years biochar application to a sandy loam field

    DEFF Research Database (Denmark)

    Sun, Zhencai; Arthur, Emmanuel; de Jonge, Lis Wollesen

    2015-01-01

    Soil pore structure comprises the size and shape of soil pores and has a major impact on water retention and gas movement. The porous nature of biochar suggests that its application to soil can potentially alter soil pore structure characteristics, and the purpose of this study was to evaluate...... the effects of birch wood biochar (20, 40, and 100 Mg ha−1) applied to a sandy loam on soil total porosity and pore structure indices. Bulk and intact soil samples were collected for physicochemical analyses and water retention and gas diffusivity measurements between pF 1.0 and pF 3.0. Biochar application...... reduced bulk density and increased total porosity especially for soil with 100 Mg ha−1 biochar (16% and 14% reduction in bulk density and total porosity, respectively). Biochar application of more than 20 Mg ha−1 enhanced water retention, and the trend increased with increasing biochar application rate...

  15. A Bioassay Technique to Study Clomazone Residues in Sandy Loam Soil

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    Jelena Gajić Umiljendić

    2013-01-01

    Full Text Available A bioassay test was conducted to evaluate the sensitivity of maize, sunflower and barley toclomazone residues in sandy loam soil. Clomazone was applied at different rates from 0.12 to12 mg a.i./kg of soil. The parameters measured 14 days after treatment were: shoot height, freshand dry weight, and content of pigments (carotenoids, chlorophyll a and chlorophyll b. Theresults showed that the lowest clomazone concentration caused a significant reduction in allmeasured parameters for barley and sunflower shoots. Fresh weight of maize shoots was notsensitive to clomazone residual activity in soil while the other parameters were highly inhibited.Nomenclature: clomazone (2-(2-chlorbenzyl-4,4-dimethyl-1,2-oxazolidin-3-one, maize(Zea mays L., sunflower (Helianthus annuus L., barley (Hordeum vulgare L.

  16. Effects of biochar and manure amendments on water vapor sorption in a sandy loam soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per;

    2015-01-01

    properties of soils, especially on water retention at low matric potentials. To overcome this knowledge gap, the effects of combined BC (0 to 100 Mg ha-1) and manure (21 and 42 Mg ha-1) applications on water vapor sorption and specific surface area was investigated for a sandy loam soil. In addition......, potential impacts of BC aging were evaluated. All considered BC-amendment rates led to a distinct increase of water retention, especially for low matric potentials. The observed increases were attributed to a significant increase of soil organic matter contents and specific surface areas in BCamended soils......Over the last few years, the application of biochar (BC) as a soil amendment to sequester carbon and mitigate global climate change has received considerable attention. While positive effects of biochar on plant nutrition are well documented, little is known about potential impacts on the physical...

  17. The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1996-01-01

    .), or it was applied to ryegrass one month after sowing. In a sandy loam soil, 62% of the incorporated urine N and 78% of the incorporated urea N was recovered in three cuts of herbage after 5 months. In a sandy soil, 51-53% of the labelled N was recovered in the herbage and the distribution of labelled N in plant...... and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33-34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20...... unaccounted for was probably mainly lost by ammonia volatilization. Significantly more urine- than urea-derived N (36 and 19%, respectively) was immobilized in the sandy loam soil, whereas the immobilization of N from urea and urine was similar in the sandy soil (13-16%). The distribution of urine N, whether...

  18. Leaching and ponding of viral contaminants following land application of biosolids on sandy-loam soil.

    Science.gov (United States)

    Wong, Kelvin; Harrigan, Tim; Xagoraraki, Irene

    2012-12-15

    Much of the land available for application of biosolids is cropland near urban areas. Biosolids are often applied on hay or grassland during the growing season or on corn ground before planting or after harvest in the fall. In this study, mesophilic anaerobic digested (MAD) biosolids were applied at 56,000 L/ha on a sandy-loam soil over large containment lysimeters seeded to perennial covers of orchardgrass (Dactylis glomerata L.), switchgrass (Panicum virgatum), or planted annually to maize (Zea mays L.). Portable rainfall simulators were to maintain the lysimeters under a nearly saturated (90%, volumetric basis) conditions. Lysimeter leachate and surface ponded water samples were collected and analyzed for somatic phage, adenoviruses, and anionic (chloride) and microbial (P-22 bacteriophage) tracers. Neither adenovirus nor somatic phage was recovered from the leachate samples. P-22 bacteriophage was found in the leachate of three lysimeters (removal rates ranged from 1.8 to 3.2 log(10)/m). Although the peak of the anionic tracer breakthrough occurred at a similar pore volume in each lysimeter (around 0.3 pore volume) the peak of P-22 breakthrough varied between lysimeters (worm holes or other natural phenomena. The concentration of viral contaminants collected in ponded surface water ranged from 1 to 10% of the initial concentration in the applied biosolids. The die off of somatic phage and P-22 in the surface water was fit to a first order decay model and somatic phage reached background level at about day ten. In conclusion, sandy-loam soils can effectively remove/adsorb the indigenous viruses leached from the land-applied biosolids, but there is a potential of viral pollution from runoff following significant rainfall events when biosolids remain on the soil surface.

  19. Response of the microbial community to copper oxychloride in acidic sandy loam soil.

    Science.gov (United States)

    Du Plessis, K R; Botha, A; Joubert, L; Bester, R; Conradie, W J; Wolfaardt, G M

    2005-01-01

    Determining the response of different microbial parameters to copper oxychloride in acidic sandy loam soil samples using cultivation-dependent and direct microscopic techniques. Culturable microbial populations were monitored for 245 days in a series of soil microcosms spiked with different copper oxychloride concentrations. Microbial populations responded differently to additional Cu. Protistan numbers and soil metabolic potential decreased. Experiments with more soil samples revealed that metabolic potential was not significantly affected by protista was noted in soil containing only 15 mg kg(-1) EDTA-extractable Cu. The negative impact on protistan numbers was less severe in soils with a higher phosphorous and zinc content. Bacterial populations responded differently, and protista were most sensitive to elevated Cu levels. Protistan numbers in soil from uncultivated land were higher and seemed to be more sensitive to additional Cu than the numbers of these organisms in soil originating from cultivated land. Protistan sensitivity to small increases in Cu levels demonstrates the vulnerability of the soil ecosystem to Cu perturbations, especially when the importance of protista as link in the flow of energy between trophic levels is considered.

  20. Characterisation of phosphate solubilising bacteria in sandy loam soil under chickpea cropping system.

    Science.gov (United States)

    Singh, Machiavelli; Tejo Prakash, N

    2012-06-01

    With the aim to explore the possible role of phosphate-solubilizing bacteria (PSB) in phosphorus (P) cycling in agricultural soils, we isolated PSB inhabiting naturally in the sandy loam soils under chickpea cropping of Patiala (Punjab State). A total of 31 bacterial isolates showing solubilizing activities were isolated on Pikovskaya agar plates. The potent phosphate solubilizers were selected for further characterization. These isolates were shown to belong to the genera Pseudomonas and Serratia by partial sequencing analysis of their respective 16S rDNA genes. ERIC-PCR based fingerprinting was done for tracking the survival of introduced populations of the PSB during mass inoculation of these strains under chickpea plots. The results showed positive correlation (r(2) = 0.853) among soil phosphatase activity and phosphate solubilizers population, which was also positively correlated (r(2) = 0.730) to available phosphorus. Identification and characterization of soil PSB for the effective plant growth-promotion broadens the spectrum of phosphate solubilizers available for field application.

  1. Phytotoxicity and uptake of nitroglycerin in a natural sandy loam soil.

    Science.gov (United States)

    Rocheleau, Sylvie; Kuperman, Roman G; Dodard, Sabine G; Sarrazin, Manon; Savard, Kathleen; Paquet, Louise; Hawari, Jalal; Checkai, Ronald T; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I

    2011-11-15

    Nitroglycerin (NG) is widely used for the production of explosives and solid propellants, and is a soil contaminant of concern at some military training ranges. NG phytotoxicity data reported in the literature cannot be applied directly to development of ecotoxicological benchmarks for plant exposures in soil because they were determined in studies using hydroponic media, cell cultures, and transgenic plants. Toxicities of NG in the present studies were evaluated for alfalfa (Medicago sativa), barnyard grass (Echinochloa crusgalli), and ryegrass (Lolium perenne) exposed to NG in Sassafras sandy loam soil. Uptake and degradation of NG were also evaluated in ryegrass. The median effective concentration values for shoot growth ranged from 40 to 231 mg kg(-1) in studies with NG freshly amended in soil, and from 23 to 185 mg kg(-1) in studies with NG weathered-and-aged in soil. Weathering-and-aging NG in soil did not significantly affect the toxicity based on 95% confidence intervals for either seedling emergence or plant growth endpoints. Uptake studies revealed that NG was not accumulated in ryegrass but was transformed into dinitroglycerin in the soil and roots, and was subsequently translocated into the ryegrass shoots. The highest bioconcentration factors for dinitroglycerin of 685 and 40 were determined for roots and shoots, respectively. Results of these studies will improve our understanding of toxicity and bioconcentration of NG in terrestrial plants and will contribute to ecological risk assessment of NG-contaminated sites.

  2. Retention and transport of mecoprop on acid sandy-loam soils

    Science.gov (United States)

    Paradelo Núñez, Remigio; Conde Cid, Manuel; Abad, Elodie Martin; Fernández Calviño, David; Nóvoa Muñoz, Juan Carlos; Arias Estévez, Manuel

    2017-04-01

    Interaction with soil components is one of the key processes governing the fate of agrochemicals in the environment. In this work, we have studied the adsorption/desorption and transport of mecoprop in four acid sandy-loam soils with different organic matter contents. Kinetics of adsorption and adsorption/desorption at equilibrium have been studied in batch experiments, whereas transport was studied in laboratory columns. Adsorption and desorption are linear or nearly-linear. The kinetics of mecoprop adsorption are relatively fast in all cases (less than 24 h). Adsorption and desorption were adequately described by the linear and Freundlich models, with KF values that ranged from 0.7 to 8.8 Ln µmol1-n kg-1 and KD values from 0.3 to 3.6 L kg-1. High desorption percentages (>50%) were found, indicative of a high reversibility of the adsorption process. The results of the transport experiments showed that the retention of mecoprop by soil was very low (less than 6.2%). The retention of mecoprop by the soils in all experiments increased with organic matter content. Overall, it was observed that mecoprop was weakly adsorbed by the soils, what would result in a high risk of leaching of this compound.

  3. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils

    OpenAIRE

    B. Anuradha; Rekhapadmini, A.; Rangaswamy, V.

    2016-01-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5....

  4. Studies on amendment of different biopolymers in sandy loam and their effect on germination, seedling growth of Gossypium herbaceum L.

    Science.gov (United States)

    Patil, Satish Vitthalrao; Salunke, B K; Patil, C D; Salunkhe, R B

    2011-03-01

    Different biopolymers, agar, cellulose, alginate, psyllium gaur gum, and bacterial exopolysaccharide (EPS) powders were amended to check their efficacy in enhancing maximum water holding capacity (MWHC), permanent wilting point (PWP), and germination and seedling growth of the Gossypium herbaceum in a laboratory scale. The efficacy of all biopolymers for enhancement of MWHC, PWP, and growth was also analyzed by measuring organic carbon, organic matter, total nitrogen, respiration rate, and microflora in amended and control sandy loams. The range of concentrations (0.2-2%) of all biopolymers was incorporated in sandy loam containing pots. The soil without polymer was considered as control. The psyllium (0.6%) and bacterial EPS (1%) amended soil has 242 and 233% increase in MWHC and thus delaying in the permanent wilting point by 108 and 84 h at 37 °C, respectively, as compared to control. All biopolymers found to increase more or less MWHC, organic matter, total nitrogen, microflora, and PWP as compared to control. The psyllium and bacterial EPS show the highest increase organic matter, biomass, and microflora. The highest reduction in MWHC after 12 weeks were observed in cellulose, gaur gum, and alginate; besides, psyllium, bacterial EPS, and agar showed comparatively less reduction MWHC, i.e., 24% and 14.5%, respectively. The toxicity studies of biopolymer were carried out on earthworm (Eisenia foetida). It revealed their nontoxic nature. The biopolymer amendment in sandy loam can be an effective strategy to improved soil texture, fertility, and thereby crop yield.

  5. Experimental studies on the physico-mechanical properties of jet-grout columns in sandy and silty soils

    Science.gov (United States)

    Akin, Muge K.

    2016-04-01

    The term of ground improvement states to the modification of the engineering properties of soils. Jet-grouting is one of the grouting methods among various ground improvement techniques. During jet-grouting, different textures of columns can be obtained depending on the characteristics of surrounding subsoil as well as the adopted jet-grouting system for each site is variable. In addition to textural properties, strength and index parameters of jet-grout columns are highly affected by the adjacent soil. In this study, the physical and mechanical properties of jet-grout columns constructed at two different sites in silty and sandy soil conditions were determined by laboratory tests. A number of statistical relationships between physical and mechanical properties of soilcrete were established in this study in order to investigate the dependency of numerous variables. The relationship between qu and γd is more reliable for sandy soilcrete than that of silty columns considering the determination coefficients. Positive linear relationships between Vp and γd with significantly high determination coefficients were obtained for the jet-grout columns in silt and sand. The regression analyses indicate that the P-wave velocity is a very dominant parameter for the estimation of physical and mechanical properties of jet-grout columns and should be involved during the quality control of soilcrete material despite the intensive use of uniaxial compressive strength test. Besides, it is concluded that the dry unit weight of jet-grout column is a good indicator of the efficiency of employed operational parameters during jet-grouting.

  6. Aggregate-associated carbon and nitrogen in reclaimed sandy loam soils

    Energy Technology Data Exchange (ETDEWEB)

    Wick, A.F.; Stahl, P.D.; Ingram, L.J. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2009-11-15

    Minimal research has been conducted on aggregate, C, and N in coarse-textured soils used to reclaim surface coal mine lands. Furthermore, little is known about the contribution different plant communities make to the recovery of aggregation in these soils. Two chronosequences of semiarid reclaimed sites with sandy loam soils were sampled under shrub- and grass-dominated communities. Aggregation, aggregate fractions, and associated C and N were measured. No definitive trends of increasing macroaggregates between sites were observed undershrubs; however, macro- and microaggregation was greater in the 16-yr-old (0.20 and 0.23 kg aggregate kg{sup -1} soil, respectively) than in the 5-yr-old soils (0.02 and 0.08 kg aggregate kg{sup -1} soil, respectively) under grasses. Although C and N concentrations were drastically reduced (50-75%) with mining activity between the <1-yr-old and native soils, aggregate C and N concentrations tinder shrubs and grasses were similar to each other and to the native soils in the 5-yr-old site. Sods under grass in the 16-yr-old site had lower available and aggregate-occluded C and N concentrations than the 5-yr-old site, while C and N concentrations did not change between 5- and 16-yr-old soils under shrubs. Conversely, aggregate C and N pool sizes under shrubs and grasses both increased with site age to conditions similar to those observed in the native soil. Reclaimed shrub site soils had consistently higher C concentrations in the older reclaimed sites (10 and 16 yr old) than the soils under grasses, indicating greater accumulation and retention of C and N in organic material under shrub than grass communities in semiarid reclaimed sites.

  7. Transport and Retention of Toxoplasma gondii Oocysts in Loamy Sand and Sandy Loam Soils

    Science.gov (United States)

    Kinsey, E. N.; Korte, C.; L'Ollivier, C.; Dubey, J. P.; Aurélien, D.; Darnault, C. J. G.

    2016-12-01

    Toxoplasma gondii is one of the most prevalent parasites affecting warm-blooded animals and humans. It has a complex life cycle that involves a wide variety of intermediate hosts with felids as a definitive host. Humans may contract it through consumption of infected, undercooked meat or by water or food sources contaminated with the oocyst form of the parasite. Infection of pregnant women can cause stillbirth, neurological effects or blindness. Because of the prevalence of cats, including on farms where oocyst-contaminated cat feces, animal feed, soil and water have been found, T. gondii is spread almost throughout the entire globe. It has been implicated or suspected in waterborne infections since the 1990s. This study aims to characterize the transport and retention of T. gondii oocysts in field soils. The four soils used were collected from fallow and cultivated fields in Illinois and Utah, USA. They are classified as loamy sands and sandy loams. Soil columns were subjected to continuous artificial rainfall until they reached steady state at which point pulses that included 2.5 million T. gondii oocysts (Me49 strain) and KBr as a tracer were added. After the pulse infiltrated, continuous rainfall was resumed. Rain applied all columns was a 1 mM KCl solution. Leachate samples were collected, analyzed using qPCR for T. gondii and bromide ions and breakthrough curves were produced. Soil was sliced into 1 to 2 cm sections, for which water content and T. gondii concentration were measured to access degree of saturation and oocyst retention.

  8. Imazaquin degradation and metabolism in a sandy loam soil amended with farm litters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Imazaquin applied in legume crops has a long residual time in soil,which often impacts safety of the susceptible crops.To increase safety of imazaquin application,two composted litters,bovine manure (BM) and chicken manure (CM),were used to determine their effects on imazaquin environmental behavior by incorporating each kind of manure into the tested sandy loam soil at 10% (w/w).The degradation of imazaquin in BM- and CM-amended soil was about 2.4 and 1.5 times,respectively,faster than that in unamended soil.The half-lives of imazaquin in BM-amended soil varied between 6.7 and 15.4 d over the temperature range of 20 to 40℃,and the degradation rate constant (k) increased by a factor of about 1.5 for every 10℃ change.Higher mix ratio did not significantly increase the degradation,and the optimal active degradation of imazaquin was observed approximately at the mix ratio of 10:1 of soil to BM.The different moisture levels had negligible effect on imazaquin degradation.In both unamended and BM-amended treatments.two metabolites were observed at 5,10 and 30 d after treatment.One metabolite at retention time (RT) of 8.4 min was identified as 2-(4-hydroxyl-5-oxo-2-imidazolin-2-y1) quinoline acid,originating from the loss of isopropyl group and hydroxylation at the 4-position of imidazolinone ring.The other at RT of 12.9 min was identified as quinolinc-2,3-dicarboxylic anhydride,resulting from detachment of imidazolinone ring and the forming of dicarboxylic anhydride.This finding suggested that the addition of farm litters into soil might be a good management option since it can not only increase soil fertility but also contribute to increase safety of imazaquin application to the following susceptible crops.

  9. Effects of biochar and maize straw on the short-term carbon and nitrogen dynamics in a cultivated silty loam in China.

    Science.gov (United States)

    Zhu, Li-Xia; Xiao, Qian; Shen, Yu-Fang; Li, Shi-Qing

    2017-01-01

    Application of maize straw and biochar can potentially improve soil fertility and sequester carbon (C) in the soil, but little information is available about the effects of maize straw and biochar on the mineralization of soil C and nitrogen (N). We conducted a laboratory incubation experiment with five treatments of a cultivated silty loam, biochar produced from maize straw and/or maize straw: soil only (control), soil + 1 % maize straw (S), soil + 4 % biochar (B1), soil + 4 % biochar + 1 % maize straw (B1S), and soil + 8 % biochar + 1 % maize straw (B2S). CO2 emissions, soil organic C, dissolved organic C, easily oxidized C, total N, mineral N, net N mineralization, and microbial biomass C and N of three replicates were measured periodically during the 60-day incubation using destructive sampling method. C mineralization was highest in treatment S, followed by B2S, B1S, the control, and B1. Total net CO2 emissions suggested that negative or positive priming effect may occur between the biochar and straw according to the biochar addition rate, and biochar mineralization was minimal. By day 35, maize straw, irrespective of the rate of biochar addition, significantly increased microbial biomass C and N but decreased dissolved organic N. Biochar alone, however, had no significant effect on either microbial biomass C or N but decreased dissolved organic N. Mixing the soil with biochar and/or straw significantly increased soil organic C, easily oxidized C and total N contents, and decreased dissolved organic N content. Dissolved organic C contents showed mixed results. Notably, N was immobilized in soil mixed with straw and/or biochar, but the effect was stronger for soil mixed with straw, which may cause N deficiency for plant growth. The application of biochar and maize straw can thus affect soil C and N cycles, and the appropriate proportion of biochar and maize straw need further studies to increase C sequestration.

  10. Biochar effects on wet and dry regions of the soil water retention curve of a sandy loam

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Sun, Zhencai;

    2014-01-01

    Reported beneficial effects of biochar on soil physical properties and processes include decreased soil density, and increased soil water transport, water holding capacity and retention (mainly for the wet region). Research is limited on biochar effects on the full soil water retention curve (wet...... and dry regions) for a given soil and biochar amendment scenarios. This study evaluates how biochar applied to a sandy loam field at rates from 0 to 50 Mg ha−1 yr–1 in 2011, 2012, or both years (2011+2012) influences the full water retention curve. Inorganic fertilizer and pig slurry were added to all...... region-water retention curve increased with increasing biochar rates....

  11. Eleven years' effect of conservation practices for temperate sandy loams: I. Soil physical properties and topsoil carbon content

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl

    2017-01-01

    experiments were conducted in 11- to 12-yr-old experiments on two Danish sandy loams at Foulum and Flakkebjerg. Three crop rotations/residue management treatments were compared and tillage was included as a splitplot factor. The tillage systems were moldboard plowing to a depth of 20 cm (MP), direct drilling...... their important role in soil structure formation and stabilization. Our study showed benefits of combining key CA elements, although longer-term studies are most likely needed to reveal the full potential....

  12. 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%.

  13. Direct and Indirect Short-term Effects of Biochar on Physical Characteristics of an Arable Sandy Loam

    DEFF Research Database (Denmark)

    Sun, Zhencai; Moldrup, Per; Elsgaard, Lars

    2013-01-01

    Biochar addition to agricultural soil is reported in several studies to reduce climate gas emissions, boost carbon storage, and improve soil fertility and crop productivity. These effects may be partly related to soil physical changes resulting from biochar amendment, but knowledge of how biochar...... application mechanistically affects soil physical characteristics is limited. This study investigated the effect of biochar application on soil structural and functional properties, including specific surface area, water retention, and gas transport parameters. Intact soil cores were taken from a field...... experiment on an arable sandy loam that included four reference plots without biochar and four plots with 20 tons ha(-1) biochar incorporated into the upper 20 cm 7 months before sampling. Water retention was measured at matric potentials ranging from wet (pF 1.0) to extremely dry conditions (pF similar to 6...

  14. Soil water retention, air flow and pore structure characteristics after corn cob biochar application to a tropical sandy loam

    DEFF Research Database (Denmark)

    Amoakwah, Emmanuel; Frimpong, Kwame Agyei; Okae-Anti, D

    2017-01-01

    Soil structure is a key soil physical property that affects soil water balance, gas transport, plant growth and development, and ultimately plant yield. Biochar has received global recognition as a soil amendment with the potential to ameliorate the structure of degraded soils. We investigated how...... corn cob biochar contributed to changes in soil water retention, air flow by convection and diffusion, and derived soil structure indices in a tropical sandy loam. Intact soil cores were taken from a field experiment that had plots without biochar (CT), and plots each with 10 t ha− 1 (BC-10), 20 t ha...... to significant increase in soil water retention compared to the CT and BC-10 as a result of increased microporosity (pores biochar had minimal impact. No significant influence of biochar was observed for ka and Dp/D0 for the BC treatments compared to the CT despite...

  15. Biochar effects on wet and dry regions of the soil water retention curve of a sandy loam

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Sun, Zhencai

    2014-01-01

    Reported beneficial effects of biochar on soil physical properties and processes include decreased soil density, and increased soil water transport, water holding capacity and retention (mainly for the wet region). Research is limited on biochar effects on the full soil water retention curve (wet...... and dry regions) for a given soil and biochar amendment scenarios. This study evaluates how biochar applied to a sandy loam field at rates from 0 to 50 Mg ha−1 yr–1 in 2011, 2012, or both years (2011+2012) influences the full water retention curve. Inorganic fertilizer and pig slurry were added to all...... treatments. Six months after the last biochar application, intact and disturbed soil samples were collected for analyses. Soil water retention was measured from −1 kPa to −100 kPa using tension tables and ceramic plates and from −10 MPa to −480 MPa using a Vapor Sorption Analyzer. Soil specific area...

  16. [Effects of long-term fertilization on pH buffer system of sandy loam calcareous fluvor-aquic soil].

    Science.gov (United States)

    Wang, Ji-Dong; Qi, Bing-Jie; Zhang, Yong-Chun; Zhang, Ai-Jun; Ning, Yun-Wang; Xu, Xian-Ju; Zhang, Hui; Ma, Hong-Bo

    2012-04-01

    Soil samples (0-80 cm) were collected from a 30-year fertilization experimental site in Xuzhou, Jiangsu Province of East China to study the variations of the pH, calcium carbonate and active calcium carbonate contents, and pH buffer capacity of sandy loam calcareous fluvor-aquic soil under different fertilization treatments. Thirty-year continuous application of different fertilizers accelerated the acidification of topsoil (0-20 cm), with the soil pH decreased by 0.41-0.70. Under different fertilization, the soil pH buffer capacity (pHBC) varied from 15.82 to 21.96 cmol x kg(-1). As compared with no fertilization, single N fertilization decreased the pHBC significantly, but N fertilization combined with organic fertilization could significantly increase the pHBC. The soil pHBC had significant positive correlations with soil calcium carbonate and active calcium carbonate contents, but less correlation with soil organic matter content and soil cation exchange capacity, suggesting that after a long-term fertilization, the sandy loam calcareous fluvor-aquic soil was still of an elementary calcium carbonate buffer system, and soil organic matter and cation exchange capacity contributed little to the buffer system. The soil calcium carbonate and active calcium carbonate contents were greater in 0-40 cm than in 40-80 cm soil layer. Comparing with soil calcium carbonate, soil active calcium carbonate was more sensitive to reflect the changes of soil physical and chemical properties, suggesting that the calcium carbonate buffer system could be further classified as soil active calcium carbonate buffer system.

  17. Uncertainty of Deardorff’s soil moisture model based on continuous TDR measurements for sandy loam soil

    Directory of Open Access Journals (Sweden)

    Brandyk Andrzej

    2016-03-01

    Full Text Available Knowledge on soil moisture is indispensable for a range of hydrological models, since it exerts a considerable influence on runoff conditions. Proper tools are nowadays applied in order to gain in-sight into soil moisture status, especially of uppermost soil layers, which are prone to weather changes and land use practices. In order to establish relationships between meteorological conditions and topsoil moisture, a simple model would be required, characterized by low computational effort, simple structure and low number of identified and calibrated parameters. We demonstrated, that existing model for shallow soils, considering mass exchange between two layers (the upper and the lower, as well as with the atmosphere and subsoil, worked well for sandy loam with deep ground water table in Warsaw conurbation. GLUE (Generalized Likelihood Uncertainty Estimation linked with GSA (Global Sensitivity Analysis provided for final determination of parameter values and model confidence ranges. Including the uncertainty in a model structure, caused that the median soil moisture solution of the GLUE was shifted from the one optimal in deterministic sense. From the point of view of practical model application, the main shortcoming were the underestimated water exchange rates between the lower soil layer (ranging from the depth of 0.1 to 0.2 m below ground level and subsoil. General model quality was found to be satisfactory and promising for its utilization for establishing measures to regain retention in urbanized conditions.

  18. Factors driving the carbon mineralization priming effect in a sandy loam soil amended with different types of biochar

    Science.gov (United States)

    Cely, P.; Tarquis, A. M.; Paz-Ferreiro, J.; Méndez, A.; Gascó, G.

    2014-06-01

    The effect of biochar on the soil carbon mineralization priming effect depends on the characteristics of the raw materials, production method and pyrolysis conditions. The goal of the present study is to evaluate the impact of three different types of biochar on physicochemical properties and CO2 emissions of a sandy loam soil. For this purpose, soil was amended with three different biochars (BI, BII and BIII) at a rate of 8 wt% and soil CO2 emissions were measured for 45 days. BI is produced from a mixed wood sieving from wood chip production, BII from a mixture of paper sludge and wheat husks and BIII from sewage sludge. Cumulative CO2 emissions of biochars, soil and amended soil were well fit to a simple first-order kinetic model with correlation coefficients (r2) greater than 0.97. Results show a negative priming effect in the soil after addition of BI and a positive priming effect in the case of soil amended with BII and BIII. These results can be related to different biochar properties such as carbon content, carbon aromaticity, volatile matter, fixed carbon, easily oxidized organic carbon or metal and phenolic substance content in addition to surface biochar properties. Three biochars increased the values of soil field capacity and wilting point, while effects over pH and cation exchange capacity were not observed.

  19. Field performance of nine soil water content sensors on a sandy loam soil in new brunswick, maritime region, Canada.

    Science.gov (United States)

    Chow, Lien; Xing, Zisheng; Rees, Herb W; Meng, Fanrui; Monteith, John; Stevens, Lionel

    2009-01-01

    An in situ field test on nine commonly-used soil water sensors was carried out in a sandy loam soil located in the Potato Research Center, Fredericton, NB (Canada) using the gravimetric method as a reference. The results showed that among the tested sensors, regardless of installation depths and soil water regimes, CS615, Trase, and Troxler performed the best with the factory calibrations, with a relative root mean square error (RRMSE) of 15.78, 16.93, and 17.65%, and a r(2) of 0.75, 0.77, and 0.65, respectively. TRIME, Moisture Point (MP917), and Gopher performed slightly worse with the factory calibrations, with a RRMSE of 45.76, 26.57, and 20.41%, and a r(2) of 0.65, 0.72, and 0.78, respectively, while the Gypsum, WaterMark, and Netafim showed a frequent need for calibration in the application in this region.

  20. Field Performance of Nine Soil Water Content Sensors on a Sandy Loam Soil in New Brunswick, Maritime Region, Canada

    Directory of Open Access Journals (Sweden)

    Lionel Stevens

    2009-11-01

    Full Text Available An in situ field test on nine commonly-used soil water sensors was carried out in a sandy loam soil located in the Potato Research Center, Fredericton, NB (Canada using the gravimetric method as a reference. The results showed that among the tested sensors, regardless of installation depths and soil water regimes, CS615, Trase, and Troxler performed the best with the factory calibrations, with a relative root mean square error (RRMSE of 15.78, 16.93, and 17.65%, and a r2 of 0.75, 0.77, and 0.65, respectively. TRIME, Moisture Point (MP917, and Gopher performed slightly worse with the factory calibrations, with a RRMSE of 45.76, 26.57, and 20.41%, and a r2 of 0.65, 0.72, and 0.78, respectively, while the Gypsum, WaterMark, and Netafim showed a frequent need for calibration in the application in this region.

  1. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils.

    Science.gov (United States)

    Anuradha, B; Rekhapadmini, A; Rangaswamy, V

    2016-06-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5.0, 7.5 and 10.0 kg ha(-1)) and -untreated groundnut soil samples at 10 day intervals. By determining the effective concentration, the rate of selected enzyme activity was estimated by adding the suitable substrate at 10, 20, 30 and 40 days of soil incubation. Both the enzyme activities were increased up to 5.0 kg ha(-1) level of fungicide in both soil samples significantly at 10 days of soil incubation and further enhanced up to 20 days of incubation. The activity of the phosphatase and urease decreased progressively at 30 and 40 days of incubation. From overall studies, higher concentrations (7.5 and 10.0 kg ha(-1)) of both tebuconazole and copper hydroxide were toxic to phosphatase and urease activities, respectively, in both soil samples.

  2. Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study.

    Directory of Open Access Journals (Sweden)

    Weiwei Lu

    Full Text Available This study examined the effect of nitrogen (N on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant straw in absence (BC0 and presence (BCN of N and monitored for dynamics of carbon dioxide (CO2 flux, phospholipid fatty acids (PLFAs profile and dissolved organic carbon (DOC content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05, and the proportions of decomposed biochar carbon (C were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05 higher than DOC in biochar (1.75% and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05 increased the proportion of gram-positive (G+ bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G- bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil.

  3. Seasonal fluctuations in water repellency and infiltration in a sandy loam soil after a forest fire in Galicia (NW Spain

    Directory of Open Access Journals (Sweden)

    M. Rodríguez-Alleres

    2013-05-01

    Full Text Available The aim of this work was to analyze, after a wildfire of moderate severity, the temporal fluctuations in water repellency and infiltration in a sandy loam soil under a mixed plantation of pine and eucalyptus and the comparison with an adjacent area not affected by the fire. In the burnt area and in a neighboring area not affected by the fire were collected during one year (1, 4, 6, 8 and 12 months after the fire 10 soil samples along a transect of 18 m at four depths: 0-2, 2-5, 5-10 and 10-20 cm. Soil water repellency was determined using the water drop penetration time test (WDPT test and the infiltration was measured with a mini-disc infiltrometer (pressure head h0 = -2 cm.The results show a temporal pattern of soil water repellency in the burnt and unburnt areas. Significant correlations between water repellency and soil moisture were observed, with higher correlation coefficients in the unburned area and in the surface soil layer.Soil water infiltration was significantly lower than would be expected by the coarse texture of the soil in both burnt and unburnt areas. Temporal fluctuations in unburnt soil infiltration seem to be clearly related to the transient nature of the soil water repellency, with no infiltration in samples extremely repellent. In the burned area, the soil infiltration showed much more variability and temporal fluctuations appear to be less dependent on the persistence of water repellency and more dependent on environmental conditions.The unburnt area show significant and negative correlations of soil water repellency with hydraulic conductivity and sorptivity and positive of these two parameters with soil moisture. These relationships were not observed in the burnt area. The temporal fluctuations of soil water repellency have an evident impact on soil infiltration and seem to be more influent than the effects of fire.

  4. Effect of silver nano-particles on soil microbial growth, activity and community diversity in a sandy loam soil.

    Science.gov (United States)

    Samarajeewa, A D; Velicogna, J R; Princz, J I; Subasinghe, R M; Scroggins, R P; Beaudette, L A

    2017-01-01

    Silver nano-particles (AgNPs) are widely used in a range of consumer products as a result of their antimicrobial properties. Given the broad spectrum of uses, AgNPs have the potential for being released to the environment. As a result, environmental risks associated with AgNPs need to be assessed to aid in the development of regulatory guidelines. Research was performed to assess the effects of AgNPs on soil microbial activity and diversity in a sandy loam soil with an emphasis on using a battery of microbial tests involving multiple endpoints. The test soil was spiked with PVP coated (0.3%) AgNPs at the following concentrations of 49, 124, 287, 723 and 1815 mg Ag kg(-1) dry soil. Test controls included an un-amended soil; soil amended with PVP equivalent to the highest PVP concentration of the coated AgNP; and soil amended with humic acid, as 1.8% humic acid was used as a suspension agent for the AgNPs. The impact on soil microbial community was assessed using an array of tests including heterotrophic plate counting, microbial respiration, organic matter decomposition, soil enzyme activity, biological nitrification, community level physiological profiling (CLPP), Ion Torrent™ DNA sequencing and denaturing gradient gel electrophoresis (DGGE). An impact on microbial growth, activity and community diversity was evident from 49 to 1815 mg kg(-1) with the median inhibitory concentrations (IC50) as low as 20-31 mg kg(-1) depending on the test. AgNP showed a notable impact on microbial functional and genomic diversity. Emergence of a silver tolerant bacterium was observed at AgNP concentrations of 49-287 mg kg(-1) after 14-28 days of incubation, but not detectable at 723 and 1815 mg kg(-1). The bacterium was identified as Rhodanobacter sp. The study highlighted the effectiveness of using multiple microbial endpoints for inclusion to the environmental risk assessment of nanomaterials.

  5. The influence of clay-to-carbon ratio on soil physical properties in a humid sandy loam soil with contrasting tillage and residue management

    DEFF Research Database (Denmark)

    Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl; Schjønning, Per

    2016-01-01

    was sampled at the 0–10, 10–20 and 25–30 cm depths of a sandy loam soil at Flakkebjerg, Denmark in 2013. We used the experimental plots of a long-term field experiment with mouldboard ploughing (MP) and direct drilling (DD) treatments. The residue management included straw removal (−S) and straw retention (+S...... decreased clay dispersibility (p = 0.09) and increased soil friability (p b 0.05) compared with the MP soil. Direct drilling with straw removal (DD − S) resulted in higher workability compared with mouldboard ploughing with straw removal (MP − S) (p b 0.05). We defined non-complexed clay as NCC = clay −10...

  6. Seasonal differences in tillage draught on a sandy loam soil with long-term additions of animal manure and mineral fertilizers

    DEFF Research Database (Denmark)

    Peltre, Clément; Nyord, T.; Christensen, B.T.;

    2016-01-01

    Energy requirements for soil tillage are closely linked to soil properties, such as clay, water and soil organic carbon (SOC) contents. Long-term application of inorganic fertilizer and organic amendments affects SOC content but little is known about seasonal differences in tillage draught...... requirements of soils subject to contrasting nutrient management regimes. We assessed autumn and spring tillage draught following harvest of early-sown and timely sown winter wheat grown on a sandy loam in the Askov Long-Term Experiment on Animal Manure and Mineral Fertilizers. Draught force was related...... to soil texture, soil water and SOC content, shear strength and bulk density, nutrient management, and yield of the preceding winter wheat. Contents of clay and SOC ranged from 8.9 to 10.6% and from 0.98 to 1.36%, respectively. In the autumn and spring, SOC normalized by clay content explained 38 and 5...

  7. Effect of nutrients and plant growth regulators on growth and yield of black gram in sandy loam soils of Cauvery new delta zone, India

    Directory of Open Access Journals (Sweden)

    S. Marimuthu

    2015-12-01

    Full Text Available Pulse productivity is very low in some of the sandy soil areas where, soils are having poor water and nutrient holding capacity. To improve the pulse productivity, field experiments were conducted at Agricultural Research Station, Tamil Nadu for two consecutive years to study the effect of phosphorus sources (mono- and diammonium phosphate with brassinolide and salicylic acid on growth and yield of black gram in sandy loam soils. The experiment was carried out in a randomized block design with three replications during kharif season. The treatments include 100% recommended dose of NPK along with foliar application of monoammonium phosphate (MAP, diammonium phosphate (DAP, brassinolide (0.25 ppm, and salicylic acid (100 ppm along with the combination of these treatments. TNAU pulse wonder at 5.0 kg ha−1 and TNAU micronutrient mixture (MN at 5 kg ha−1 were also tried. The results revealed that application of 100% recommended dose of NPK + DAP 2% + TNAU pulse wonder 5.0 kg ha−1 was statistically significant and recorded higher plant growth (37.62 cm, number of pods / plant (37.15, yield of black gram (1162 kg ha−1, and benefit cost ratio (2.98 over the other treatments. The lowest black gram yield (730 kg ha−1 was recorded for control.

  8. The impacts of pyrolysis temperature and feedstock type on biochar properties and the effects of biochar application on the properties of a sandy loam

    Science.gov (United States)

    Aston, Steve; Doerr, Stefan; Street-Perrott, Alayne

    2013-04-01

    The production of biochar and its application to soil has the potential to make a significant contribution to climate change mitigation whilst simultaneously improving soil fertility, crop yield and soil water-holding capacity. Biochar is produced from various biomass feedstock materials at varying pyrolysis temperatures, but relatively little is known about how these parameters affect the properties of the resultant biochars and their impact on the properties of the soils to which they are subsequently applied. Salix viminalis, M. giganteus and Picea sitchensis feedstocks were chipped then sieved to 2 - 5 mm, oven dried to constant weight, then pyrolyzed at 350, 500, 600 and 800° C in a nitrogen-purged tube furnace. Biochar yields were measured by weighing the mass of each sample before and after pyrolysis. Biochar hydrophobicity was assessed by using a goniometer to measure water-droplet contact-angles. Cation-exchange-capacity (CEC) was measured using the ammonium acetate method. Biochars were also produced in a rotary kiln from softwood pellets at 400, 500, 600 and 700° C then ground to 0.4 - 1 mm and applied to a sandy loam at a rate of 50 g kg-1. Bulk densities of these soil-biochar mixtures were measured on a tapped, dry, basis. The water-holding-capacity (WHC) of each mixture was measured gravimetrically following saturation and free-draining. The filter paper method was used to assess how pyrolysis temperature influences the effect of biochar application on matric suction. For all feedstocks, large decreases in biochar yield were observed between the pyrolysis temperatures of 350° C and 500° C. For Salix viminalis and M. giganteus feedstocks, subsequent reductions in the yield with increasing pyrolysis temperature were much lower. There were significant differences in hydrophobicity between biochars produced from different biomass and mean biochar hydrophobicity decreased with increasing pyrolysis temperature for all feedstocks. Results for CEC and WHC

  9. Fate of carbosulfan and monocrotophos in sandy loam soils of Pakistan under field conditions at different watertable depths.

    Science.gov (United States)

    Tariq, Muhammad Ilyas; Afzal, Shahzad; Shahzad, Farina

    2010-05-01

    Information regarding pesticide mobility is critical for the evaluation of pesticide management practices. For this purpose, lysimetric studies were conducted to develop assessment schemes to protect groundwater from unacceptable effects caused by pesticide use. By using these studies, specific monitoring actions and prevention measures for the protection of waters can be studied, and the results thus obtained can provide the local authorities and the decision makers with an identification tool for demarcating risk areas. Pesticide residues were found at the bottom of lysimeters in the following pattern i.e., 1.52 > 2.1 > 2.74 m which could represent an "index of risk" for groundwater pollution. Regressions built for carbofuran and monocrotophos against watertable depths showed a decreasing trend of pesticide in higher watertable treatments. These findings support the existence of a significant role for chromatographic flow in sandy texture soil. Moreover, the higher values of pesticide residue at the bottom of lysimeters reflect that chromatographic flow as well as preferential flow pattern prevails during higher precipitation events. The precipitation received during the study was higher than the 10 year average and can be considered relatively as a worst case scenario. Finally, the authors have recommended a standardized pesticide monitoring scheme for groundwater in accordance with the already validated generic schemes in developed countries.

  10. Physical-hydraulic properties of a sandy loam typic paleudalf soil under organic cultivation of 'montenegrina' mandarin (Citrus deliciosa Tenore¹

    Directory of Open Access Journals (Sweden)

    Caroline Valverde dos Santos

    2014-12-01

    Full Text Available Citrus plants are the most important fruit species in the world, with emphasis to oranges, mandarins and lemons. In Rio Grande do Sul, Brazil, most fruit production is found on small properties under organic cultivation. Soil compaction is one of the factors limiting production and due to the fixed row placement of this crop, compaction can arise in various manners in the interrows of the orchard. The aim of this study was to evaluate soil physical properties and water infiltration capacity in response to interrow management in an orchard of mandarin (Citrus deliciosa Tenore 'Montenegrina' under organic cultivation. Interrow management was performed through harrowing, logs in em "V", mowing, and cutting/knocking down plants with a knife roller. Soil physical properties were evaluated in the wheel tracks of the tractor (WT, between the wheel tracks (BWT, and in the area under the line projection of the canopy (CLP, with undisturbed soil samples collected in the 0.00-0.15, 0.15-0.30, 0.30-0.45, and 0.45-0.60 m layers, with four replicates. The soil water infiltration test was performed using the concentric cylinder method, with a maximum time of 90 min for each test. In general, soil analysis showed a variation in the physical-hydraulic properties of the Argissolo Vermelho-Amarelo distrófico arênico (sandy loam Typic Paleudalf in the three sampling sites in all layers, regardless of the management procedure in the interrows. Machinery traffic leads to heterogeneity in the soil physical-hydraulic properties in the interrows of the orchard. Soil porosity and bulk density are affected especially in the wheel tracks of the tractor (WT, which causes a reduction in the constant rate of infiltration and in the accumulated infiltration of water in this sampling site. The use of the disk harrow and mower leads to greater harmful effects on the soil, which can interfere with mandarin production.

  11. Effect of rainfall and tillage direction on the evolution of surface crusts, soil hydraulic properties and runoff generation for a sandy loam soil

    Science.gov (United States)

    Ndiaye, Babacar; Esteves, Michel; Vandervaere, Jean-Pierre; Lapetite, Jean-Marc; Vauclin, Michel

    2005-06-01

    The study was aimed at evaluating the effect of rainfall and tillage-induced soil surface characteristics on infiltration and runoff on a 2.8 ha catchment located in the central region of Senegal. This was done by simulating 30 min rain storms applied at a constant rate of about 70 mm h -1, on 10 runoff micro-plots of 1 m 2, five being freshly harrowed perpendicularly to the slope and five along the slope (1%) of the catchment. Runoff was automatically recorded at the outlet of each plot. Hydraulic properties such as capillary sorptivity and hydraulic conductivity of the sandy loam soil close to saturation were determined by running 48 infiltration tests with a tension disc infiltrometer. That allowed the calculation of a mean characteristic pore size hydraulically active and a time to ponding. Superficial water storage capacity was estimated using data collected with an electronic relief meter. Because the soil was subject to surface crusting, crust-types as well as their spatial distribution within micro-plots and their evolution with time were identified and monitored by taking photographs at different times after tillage. The results showed that the surface crust-types as well as their tillage dependent dynamics greatly explain the decrease of hydraulic conductivity and sorptivity as the cumulative rainfall since tillage increases. The exponential decaying rates were found to be significantly greater for the soil harrowed along the slope (where the runoff crust-type covers more than 60% of the surface after 140 mm of rain) than across to the slope (where crusts are mainly of structural (60%) and erosion (40%) types). That makes ponding time smaller and runoff more important. Also it was shown that soil hydraulic properties after about 160 mm of rain were close to those of untilled plot not submitted to any rain. That indicates that the effects of tillage are short lived.

  12. Sorption/desorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane(4,4'-DDT) on a sandy loam soil.

    Science.gov (United States)

    Erdem, Ziya; Cutright, Teresa J

    2015-02-01

    1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane(4,4'-DDT) is a pesticide well-known for its negative health and environmental effects. Despite being banned by a majority of world countries more than 30 years ago, its persistence in the environment is a continuing problem even today. The objective of the study was the investigation of sorption/desorption behavior of 4,4'-DDT in sandy loam soil. The impact of contaminant concentration and age was observed with three different experiments. The sorption percentages at the end of the short time step (8 h) were 50 and 92 %, for initial concentrations 2.26 and 5.28 mg/L, respectively. When freshly spiked soil was subjected to a conventional sorption study, 82 to 99.6 % of the initial aqueous DDT concentrations were sorbed within 24 h. When modeled with a Freundlich isotherm, the log K f was found to be 3.62. After six consecutive 24 h desorption steps, 33 to 96.6 % still remained in the soil. This was more pronounced for soils that had been aged for 60 days. After seven consecutive 24 h desorption steps of aged soil, the percent remaining sorbed to the soil were 44, 64, and 77 %, for 25, 250, and 500 mg/kg, respectively. All results show that 4,4-DDT has a tendency of sorbing to the soil rapidly and showing resistance to desorption. When comparing desorption values, aged soils were seen to desorb less than non-aged soils. This result was attributed to stronger binding to soil with increased contact time.

  13. Effects of long-term amendment of organic manure and nitrogen fertilizer on nitrous oxide emission in a sandy loam soil

    Institute of Scientific and Technical Information of China (English)

    DING Wei-xin; MENG Lei; CAI Zu-cong; HAN Feng-xiang

    2007-01-01

    To understand the effects of long-term amendment of organic manure and N fertilizer on N2O emission in the North China Plain,a laboratory incubation at different temperatures and soil moistures were carried out using soils treated with organic manure (OM),half organic manure plus half fertilizer N (HOM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (NK) and control (CK) since 1989. Cumulative N2O emission in OM soil during the 17 d incubation period was slightly higher than in NPK soil under optimum nitrification conditions (25C and 60% water-filled pore space, WFPS), but more than twice under the optimum denitrification conditions (35C and 90% WFPS). N2O produced by denitrification was 2.1-2.3 times greater than that by nitrification in OM and HOM soils, but only 1.5 times greater in NPK and NP soils. These results implied that the long-term amendment of organic manure could significantly increase the N2O emission via denitrification in OM soil as compared to NPK soil. This is quite different from field measurement between OM soil and NPK soil. Substantial inhibition of the formation of anaerobic environment for denitrification in field might result in no marked difference in N2O emission between OM and NPK soils. This is due in part to more rapid oxygen diffusion in coarse textured soils than consumption by aerobic microbes until WFPS was 75% and to low easily decomposed organic C of organic manure. This finding suggested that addition of organic manure in the tested sandy loam might be a good management option since it seldom caused a burst of N2O emission but sequestered atmospheric C and maintained efficiently applied N in soil.

  14. Peanut plant growth and yield as influenced by co-inoculation with Bradyrhizobium and some rhizo-microorganisms under sandy loam soil conditions

    Directory of Open Access Journals (Sweden)

    F.Sh.F. Badawi

    2011-06-01

    Full Text Available The ability of tested rhizomicrobial isolates (Serratia marcescens and Trichoderma harzianum along with a strain of root nodule bacteria (Bradyrhizobium spp. to exhibit some PGP-properties was evaluated in vitro conditions. The main PGP-properties, namely the ability to solubilize-P and production of IAA, as well as production of siderophores and HCN were examined. Additionally, field trials were conducted on sandy loam soil at El-Tahrir Province during two successive summer seasons to study the effect of co-inoculation with Bradyrhizobium either individually or together with S. marcescens and/or T. harzianum on nodulation, some plant growth characters, peanut yield and its yield components. The in vitro experiment revealed that all of the tested microorganisms were apparently able to trigger PGP-properties. Phosphate solubilization was the common feature of the employed microorganisms. However, T. harzianum appeared to be superior to other microorganisms, and Bradyrhizobium displayed the lowest capacity. The ability of the microorganisms to produce indole compounds showed that S. marcescens was more effective in IAA production and followed by Bradyrhizobium. Capacity of S. marcescens and T. harzianum to excrete ferric-specific ligands (siderophores and HCN was detected, while Bradyrhizobium failed to produce such compounds. Results of field trials showed that the uninoculated peanut had the least nodulation status, N2-ase activity and all vegetative growth characters in both studied seasons. Bacterization of peanut seeds with bradyrhizobia exerted considerable improvement in number and mass of root nodules, increased the rate of acetylene reduction and all growth characters in comparison to the uninoculated control. The synergy inoculation between bradyrhizobia and any of the tested microorganisms led to further increases of all mentioned characters and strengthened the stimulating effect of the bacterial inoculation. However, the promotive

  15. The Effects of Land Configuration and Wood-Shavings Mulch on the Properties of a Sandy Loam Soil in Northeast Nigeria. 2. Changes in Physical Properties

    Directory of Open Access Journals (Sweden)

    Chiroma, AM.

    2006-01-01

    Full Text Available Mulching and ridge tillage are proven technologies for improving soil productivity in semi-arid regions. Yet data quantifying the combined influences of these practices are limited. Our objectives were to determine the changes in selected physical properties of a sandy loam after 4-years of annual tillage and wood-shavings mulching. The tillage and wood-shavings treatments consisted of: Flat bed (FB, Open ridge (OR, Tiedridge (TR, FBM, ORM and TRM were same as FB, OR and TR, respectively except that wood-shavings at a rate of 10 t/ha were surface applied ≈ 2 weeks after sowing each year to serve as both a mulch and an organic amendment. At the end of the trial in 2002, bulk density, penetration resistance, total porosity and soil water content from each of 0-0.075, 0.075-0.15 and 0.15-0.30 m depths were determined. Composite samples from the surface (0.075 and 0.075-0.15 m layers from 3 replicates of each treatment were also collected for the determination of wet aggregate stability and from 0-0.15 m and 0.15-0.30 m layers for determination of saturated hydraulic conductivity (Ksat. After 4 years of annual tillage and addition of woodshavings, soil bulk density and penetration resistance were consistently lower and total porosity higher in the FBM, ORM and TRM treatments than in the FB, OR and TR treatments. Penetration resistance in all treatments was strongly related to soil water content. A 'hoe pan' was established below 0.15 m depth beneath the furrows of the ridged treatments. This could be attributed to human traffic during field operations and ponding of water, which occurred in the furrows following heavy rains. Wet aggregate stability estimated as the proportion of aggregates of size > 0.25 mm (macro-aggregates in the 0-0.15 m layer were significantly (P< 0.05 higher under FBM, ORM and TRM than under FB, OR or TR treatments. Ksat was not influenced by either tillage or wood-shavings treatments but were higher for the mulched plots

  16. Fingerlike wetting patterns in two water-repellent loam soils

    NARCIS (Netherlands)

    Dekker, L.W.; Ritsema, C.J.

    1995-01-01

    In soils with fingered flow, surface-applied solutes can reach the groundwater more rapidly than in the case of homogeneous wetting. This study was undertaken to demonstrate the occurrence of finger-like wetting patterns in a silt loam soil and a silty clay loam soil, and to investigate the

  17. Study on Development of Leaf Tissue Structure of Flue-cured Tobacco Produced in Sandy Loam and Clay Loam in Wannan%皖南砂壤土和水稻土烤烟叶片组织结构发育规律研究

    Institute of Scientific and Technical Information of China (English)

    张国; 时向东; 季学军; 沈思灯; 马称心

    2011-01-01

    为了弄清烤烟叶片组织结构与皖南焦甜香特色风格的关系,对皖南砂壤土和水稻土烤烟叶片组织结构发育规律进行了研究.结果表明,土壤质地影响栅栏组织细胞快速分裂时期,对细胞总数的影响不明显.土壤质地间烟叶各组织厚度指标在叶肉细胞分裂期差异不大;叶肉细胞伸长前期,砂壤土烟叶栅栏组织细胞快速伸长较早,栅栏组织厚度与叶厚的比值和栅栏组织厚度与海绵组织厚度的比值也较大,而土壤质地引起的叶厚和海绵组织厚度发育差异规律在叶位间表现不一;但水稻土烟叶栅栏组织厚度、海绵组织厚度和叶厚均在叶长定长和成熟期达到或超过砂壤土水平.随着叶长的增加,皖南烤烟栅栏组织与海绵组织厚度比值和栅栏组织厚度与叶厚的比值均大体呈上升趋势.%The study results of development of leaf tissue structure of flue-cured tobacco produced in sandy loam soil and paddy soil in wannan area showed that: soil types could affect the time to cell rapid divisional of tobacco leaf palisade tissue, but not the total cell numbers. There were not obvious difference about leaf tissue thickness caused by soil types when the mesophyll cell divided; At the early stage of mesophyll cell elongation period, palisade tissue of tobacco leaf produced in sandy loam soil rapid elongated earlier, thus the thickness ratios of both palisade tissue to leaf and palisade tissue to sponge tissue were higher in this period, and the development changes in both palisade tissue thickness and leaf thickness caused by soil types were different between stalk positions; But palisade tissue thickness of the tobacco leaf produced in paddy soil reached or surpassed the levels of which produced in sandy loam soil, and so did the leaf thickness and the sponge tissue thickness. With the leaf growing, the thickness ratios of both palisade tissue to sponge tissue and palisade tissue to leaf

  18. Improvement in the water retention characteristics of sandy loam soil using a newly synthesized poly(acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite material.

    Science.gov (United States)

    Shahid, Shaukat Ali; Qidwai, Ansar Ahmad; Anwar, Farooq; Ullah, Inam; Rashid, Umer

    2012-08-03

    The use of some novel and efficient crop nutrient-based superabsorbent hydrogel nanocomposites (SHNCs), is currently becoming increasingly important to improve the crop yield and productivity, due to their water retention properties. In the present study a poly(Acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite was synthesized and its physical properties characterized using Energy Dispersive X-ray (EDX), FE-SEM and FTIR spectroscopic techniques. The effects of different levels of SHNC were studied to evaluate the moisture retention properties of sandy loam soil (sand 59%, silt 21%, clay 19%, pH 7.4, EC 1.92 dS/m). The soil amendment with 0.1, 0.2, 0.3 and 0.4 w/w% of SHNC enhanced the moisture retention significantly at field capacity compared to the untreated soil. Besides, in a separate experiment, seed germination and seedling growth of wheat was found to be notably improved with the application of SHNC. A delay in wilting of seedlings by 5-8 days was observed for SHNC-amended soil, thereby improving wheat plant growth and establishment.

  19. Hidráulica do escoamento e transporte de sedimentos em sulcos em solo franco-argilo-arenoso Flow hydraulics and sediment transport in rills of a sandy clay loam soil

    Directory of Open Access Journals (Sweden)

    José Ramon Barros Cantalice

    2005-07-01

    capacity to deform the rill and alter flow hydraulics, responsible for rill formation dynamics. The objective of this study was to evaluate flow hydraulic conditions that can provide important information on erosion relationships, soil erodibility and sediment transport in furrows of a recently-tilled Palleudult. Rills were pre-formed in a sandy clay loam soil with an average slope of 0.067 m m-1. Simulated rainfall with an intensity of 74 mm h-1 was applied during 80 min, while rainfall and extra inflows of 0, 10, 20, 30, 40, and 50 L min-1 were jointly applied for the last 20 min of each run in the rill. Results indicated that the rill flow regime varied from transitional subcritical to turbulent subcritical. The rill erosion detachment rates were linear to shear stress. Rill erodibility (Kr was 0.0024 kg-1 s-1 N and critical shear stress (tauc was 2.75 Pa. Two functions to predict sediment transport based on stream power explained 53% of data variability, which indicates the inherent difficulty of predicting solid transport through shallow flows on eroding agricultural lands, and the physical and mineralogical diversity of particles and aggregates of the studied soil.

  20. Assessment of Shear Strength in Silty Soils

    Directory of Open Access Journals (Sweden)

    Stefaniak Katarzyna

    2015-06-01

    Full Text Available The article presents a comparison of shear strength values in silty soils from the area of Poznań, determined based on selected Nkt values recommended in literature, with values of shear strength established on the basis of Nkt values recommended by the author. Analysed silty soils are characterized by the carbonate cementation zone, which made it possible to compare selected empirical coefficients both in normally consolidated and overconsolidated soils

  1. Leaching behaviour of azoxystrobin in sandy loam soil

    African Journals Online (AJOL)

    Mr HMM Mzimela

    2014-08-01

    Aug 1, 2014 ... harmful pesticide residues on the crops and in the soil. Recent studies have ... roots and translocate to stems and leaves via xylem, or through leaf ... Analysis of azoxystrobin was carried out on gas liquid chromatograph (GLC) ...

  2. Interpretation of Seismic Cone Penetration Testing in Silty Soil

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

    2016-01-01

    Five Seismic Cone Penetration Tests (SCPT) were conducted at a test site in northern Denmark where the subsoil consists primarily of sandy silt with clay bands. A portion of the test data were collected every 0.5 m to compare the efficacy of closely-spaced down-hole data collection on the computa......Five Seismic Cone Penetration Tests (SCPT) were conducted at a test site in northern Denmark where the subsoil consists primarily of sandy silt with clay bands. A portion of the test data were collected every 0.5 m to compare the efficacy of closely-spaced down-hole data collection...... on the computation of shear wave velocity. A minimum of eight seismic tests were completed at each depth in order to examine the reliability of shear wave velocity data, as well as to assess the impact of the time interval between CPT termination and seismic test initiation on SCPT results. The shear wave velocity...... increased the variability of the shear wave velocity and that time interval between seismic tests is insignificant. Correlation between shear wave velocity and cone resistance for silty soils were also determined and assessed relative to other published data on multiple soil types....

  3. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

    To engineer efficient structures offshore, we need to extend our knowledge of soil response. Cyclic loading and high water pressure encountered offshore greatly influence cohesionless soil performance. Silty sand from Frederikshavn wind turbine farm was tested using single diameter height samples...

  4. Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2013-01-01

    penetration tests with varying penetration rates conducted at a test site where the subsoil primary consists of sandy silt. It is shown how a reduced penetration rate influences the cone penetration measurements e.g. the cone resistance, pore pressure, and sleeve friction.......This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... drained penetration occurs in sand. When lowering the penetration rate, the soil pore water starts to dissipate and a change in the drainage condition is seen. In intermediate soils such as silty soils, the standard cone penetration rate may result in a drainage condition that could be undrained...

  5. Effects of Nitrogen Application Patterns on Ammonia Volatilization, Summer Maize Yield and Nitrogen Use Efficiency in Sandy Loam Fluvo-aquic Soil%施氮模式对砂质潮土氨挥发、夏玉米产量及氮肥利用率的影响

    Institute of Scientific and Technical Information of China (English)

    谢迎新; 刘园; 靳海洋; 王晨阳; 朱云集; 郭天财; 贺德先

    2015-01-01

    采用连续多年田间小区定位试验,在氮肥施用量200 kg/hm2下,观测夏玉米季不同施氮模式对夏玉米季土壤氨挥发、子粒产量及氮肥利用率的影响。结果表明,夏玉米季不同施氮处理土壤氨挥发损失量不同,当地常规施氮处理损失量最高,改变氮肥基追比处理次之,控释复合肥处理损失量最低。与不施肥对照相比,各施氮模式处理均能提高夏玉米产量,控释复合肥、改变氮肥基追比处理较当地常规施氮处理分别增产9.89%和7.14%。不同施氮模式下夏玉米季氮肥利用率以控释复合肥利用率最高,改变氮肥基追比处理次之,常规施氮最低。综合考虑,控释复合肥、改变氮肥基追比均可作为砂质潮土区推广的适宜氮肥施用模式。%Under the field experiment condition, the effects of different nitrogen application patterns on ammo⁃nia volatilization, yield of summer maize and nitrogen use efficiency were studied at the same amount of nitrogen(N) application with 200 kg/ha in summer maize season in each fertilizer treatment. There were four treatments includ⁃ing no fertilizer(CK), convention fertilizer(F1), changing basic fertilizer and topdressing regimes(F2) and controlled-release fertilizer(F3). The result showed that the amount of ammonia loss from summer maize field was different in all treatments, F1 was the highest, followed by F2, and F3 was the lowest. Compared to CK, each nitrogen applica⁃tion patterns treatment all can improve the yield of summer maize, of which F3 was best, followed by F2, compared with F1, the yield increased by 9.89%and 7.14%, respectively. In addition, the study also showed that the nitrogen use efficiency was different in all treatments, of which F3 was the highest, followed by F2, F1 was the lowest. In con⁃clusion, F3 and F2 could be taken as nitrogen application patterns by spread and application for summer maize in the sandy loam fluvo

  6. Escarificação mecânica e biológica para a redução da compactação em argissolo franco-arenoso sob plantio direto Mechanical and biological chiseling to reduce compaction of a sandy loam alfisol under no-tillage

    Directory of Open Access Journals (Sweden)

    S. L. Abreu

    2004-06-01

    saturado, em médio prazo, a "escarificação biológica" (CM-crot mostrou-se mais eficaz na ruptura da camada compactada e estabelecimento de poros condutores de água do que a escarificação mecânica (Esc-soja do solo. Em contrapartida, se o indicador for a RP, o resultado é inverso. Assim, a propriedade hídrica ou mecânica do solo a ser usada como indicadora para a avaliação da eficácia da ruptura da camada compactada do solo depende do processo físico priorizado: a infiltração e redistribuição de água ou a penetração e crescimento de raízes.Soil management alters the physical soil properties and changes the soil air, water, and solute dynamics. Physical soil properties as affected by conservationist soil management systems were studied in a sandy loam Typic Hapludalf. The treatments were established on a soil that has been under no-tillage for 10 years, and consisted of: no-tillage soybeans, chisel tillage soybeans, reduced tillage Crotalaria, and bare soil without tillage. The evaluated soil properties were soil penetration resistance, bulk density, porosity, pore size distribution, saturated and unsaturated hydraulic conductivity, water infiltration using concentric rings or natural rainfall, variation of the volumetric soil moisture throughout the cropping cycle, and water retention curve. Soil penetration resistance (PR was highest at 0.075 m and 0.175 m depth in no-tillage and chiseled soil, respectively. Soil subsurface mobilization with chiseling and surface mobilization due to disking and sowing did not influence the bulk density (BD after the crop harvest. No-till soil under soybean crop had greater macroporosity than reduced tillage crotalaria and bare soil at 0.02 to 0.05 m depth, resulting in a greater saturated hydraulic conductivity and lower water retention during periods of low water availability. Among the analyzed soil physical-mechanical properties, PR seemed to be more sensitive to detect soil compaction than BD or porosities

  7. STABILISATION OF SILTY CLAY SOIL USING CHLORIDE

    Directory of Open Access Journals (Sweden)

    TAMADHER T. ABOOD

    2007-04-01

    Full Text Available The object of this paper is to investigate the effect of adding different chloride compounds including (NaCl, MgCl2, CaCl2 on the engineering properties of silty clay soil. Various amounts of salts (2%, 4%, and 8% were added to the soil to study the effect of salts on the compaction characteristics, consistency limits and compressive strength. The main findings of this study were that the increase in the percentage of each of the chloride compounds increased the maximum dry density and decrease the optimum moisture content. The liquid limit, plastic limit and plasticity index decreased with the increase in salt content. The unconfinedcompressive strength increased as the salt content increased.

  8. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M; Ouedraogo, T; Kumar, L; Sanou, S; van Langevelde, F; Kiema, A; van de Koppel, J; van Andel, J; Hearne, J; Skidmore, AK; de Ridder, N; Stroosnijder, L; Prins, HHT

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  9. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

    2002-01-01

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  10. Impact of lfuxapyroxad on the microbial community structure and functional diversity in the silty-loam soil

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-hu; XU Jun; LIU Yong-zhuo; DONG Feng-shou; LIU Xin-gang; ZHANG Wen-wen; ZHENG Yong-quan

    2015-01-01

    The aim of this work was to assess the effect of applying three different doses of lfuxapyroxad on microbial activity, com-munity structure and functional diversity as measured by respiration, microbial biomass C, phospholipid fatty acid (PLFA) and community-level physiological proifles (CLPPs). Our results demonstrated that substrate-induced respiration (on day 15) and microbial biomass C (on days 7 and 15) were inhibited by lfuxapyroxad, but stimulation was observed thereafter. In contrast, lfuxapyroxad addition increased the basal respiration and metabolic quotients (qCO2) and respiratory quotients (QR). Analysis of the PLFA proifles revealed that the total and bacterial biomass (both Gram-positive bacteria (GP) and Gram-negative bacteria (GN)) were decreased within the initial 15 days, whereas those as wel as the GN/GP ratio were increased at days 30 and 60. Fluxapyroxad input decreased the fungi biomass but increased the bacteria/fungi ratio at al incubation time. Moreover, high lfuxapyroxad input (75 mg lfuxapyroxad kg–1 soil dry weight) increased the microbial stress level. A principal component analysis (PCA) of the PLFAs revealed that lfuxapyroxad treatment signiifcantly shifted the microbial community structure, but al of the observed effects were transient. Biolog results showed that average wel color development (AWCD) and functional diversity index (H´) were increased only on day 60. In addition, the dissipation of lfuxa-pyroxad was slow in soil, and the degradation half-lives varied from 158 to 385 days depending on the concentration tested.

  11. Impact of industrial effluent on growth and yield of rice (Oryza sativa L.) in silty clay loam soil.

    Science.gov (United States)

    Anwar Hossain, Mohammad; Rahman, Golum Kibria Muhammad Mustafizur; Rahman, Mohammad Mizanur; Molla, Abul Hossain; Mostafizur Rahman, Mohammad; Khabir Uddin, Mohammad

    2015-04-01

    Degradation of soil and water from discharge of untreated industrial effluent is alarming in Bangladesh. Therefore, buildup of heavy metals in soil from contaminated effluent, their entry into the food chain and effects on rice yield were quantified in a pot experiment. The treatments were comprised of 0, 25%, 50%, 75% and 100% industrial effluents applied as irrigation water. Effluents, initial soil, different parts of rice plants and post-harvest pot soil were analyzed for various elements, including heavy metals. Application of elevated levels of effluent contributed to increased heavy metals in pot soils and rice roots due to translocation effects, which were transferred to rice straw and grain. The results indicated that heavy metal toxicity may develop in soil because of contaminated effluent application. Heavy metals are not biodegradable, rather they accumulate in soils, and transfer of these metals from effluent to soil and plant cells was found to reduce the growth and development of rice plants and thereby contributed to lower yield. Moreover, a higher concentration of effluent caused heavy metal toxicity as well as reduction of growth and yield of rice, and in the long run a more aggravated situation may threaten human lives, which emphasizes the obligatory adoption of effluent treatment before its release to the environment, and regular monitoring by government agencies needs to be ensured.

  12. Aggregate stability and associated C and N in a silty loam soil as affected by organic material inputs

    Institute of Scientific and Technical Information of China (English)

    LONG Pan; SUI Peng; GAO Wang-sheng; WANG Bin-bin; HUANG Jian-xiong; YAN Peng; ZOU Juan-xiu; YAN Ling-ling; CHEN Yuan-quan

    2015-01-01

    To make recycling utilization of organic materials produced in various agricultural systems, ifve kinds of organic materials were applied in a ifeld test, including crop straw (CS), biogas residue (BR), mushroom residue (MR), wine residue (WR), pig manure (PM), with a mineral fertilizer (CF) and a no-fertilizer (CK) treatment as a control. Our objectives were:i) to quantify the effects of organic materials on soil C and N accumulation;i ) to evaluate the effects of organic materials on soil aggregate stability, along with the total organic carbon (TOC), and N in different aggregate fractions;and i i) to assess the relationships among the organic material components, soil C and N, and C, N in aggregate fractions. The trial was conducted in Wuqiao County, Hebei Province, China. The organic materials were incorporated at an equal rate of C, and combined with a mineral fertilizer in amounts of 150 kg N ha-1, 26 kg P ha-1 and 124 kg K ha-1 respectively during each crop season of a wheat-maize rotation system. The inputted C quantity of each organic material treatment was equivalent to the total amount of C contained in the crop straw harvested in CS treatement in the previous season. TOC, N, water-stable aggregates, and aggregate-associated TOC and N were investigated. The results showed that organic material incorpora-tion increased soil aggregation and stabilization. On average, the soil macroaggregate proportion increased by 14%, the microaggregate proportion increased by 3%, and mean-weight diameter (MWD) increased by 20%. TOC content fol owed the order of PM>WR>MR>BR>CS>CK>CF;N content fol owed the order WR>PM>MR>BR>CS>CF>CK. No signiifcant correlation was found between TOC, N, and the quality of organic material. Soil silt and clay particles contained the largest part of TOC, whereas the smal macroaggregate fraction was the most sensitive to organic materials. Our results indicate that PM and WR exerted better effects on soil C and N accumulation, fol owed by MR and BR, suggesting that organic materials from ex situ farmland could promote soil quality more as compared to straw returned in situ.

  13. Interpretation of Cone Penetration Testing in Silty Soils Conducted under Partially Drained Conditions

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2016-01-01

    The standard penetration rate used in cone penetration tests (CPTs) is 20 mm=s, regardless of soil type, which yields fully drained penetration in sand and fully undrained penetration in clay. However, for silty soils that represent an intermediate grain size composition and unique characteristics...... compared with sand and clay, the standard rate of penetration results in partially drained penetration, often leading to misinterpretation of this soil type. In this study, 15 CPTs, with penetration rates varying from 0.5 to 60 mm=s, were performed at a test site in northern Denmark, where the subsoil...... consisted primarily of sandy silt with clay bands. The results illustrated that when the penetration rate is reduced, the cone resistance increases, but the pore pressure decreases. The transition between undrained and fully drained penetration was determined by converting the results into a normalized...

  14. Behavior of nonplastic silty soils under cyclic loading.

    Science.gov (United States)

    Ural, Nazile; Gunduz, Zeki

    2014-01-01

    The engineering behavior of nonplastic silts is more difficult to characterize than is the behavior of clay or sand. Especially, behavior of silty soils is important in view of the seismicity of several regions of alluvial deposits in the world, such as the United States, China, and Turkey. In several hazards substantial ground deformation, reduced bearing capacity, and liquefaction of silty soils have been attributed to excess pore pressure generation during dynamic loading. In this paper, an experimental study of the pore water pressure generation of silty soils was conducted by cyclic triaxial tests on samples of reconstituted soils by the slurry deposition method. In all tests silty samples which have different clay percentages were studied under different cyclic stress ratios. The results have showed that in soils having clay content equal to and less than 10%, the excess pore pressure ratio buildup was quicker with an increase in different cyclic stress ratios. When fine and clay content increases, excess pore water pressure decreases constant cyclic stress ratio in nonplastic silty soils. In addition, the applicability of the used criteria for the assessment of liquefaction susceptibility of fine grained soils is examined using laboratory test results.

  15. Behavior of Nonplastic Silty Soils under Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Nazile Ural

    2014-01-01

    Full Text Available The engineering behavior of nonplastic silts is more difficult to characterize than is the behavior of clay or sand. Especially, behavior of silty soils is important in view of the seismicity of several regions of alluvial deposits in the world, such as the United States, China, and Turkey. In several hazards substantial ground deformation, reduced bearing capacity, and liquefaction of silty soils have been attributed to excess pore pressure generation during dynamic loading. In this paper, an experimental study of the pore water pressure generation of silty soils was conducted by cyclic triaxial tests on samples of reconstituted soils by the slurry deposition method. In all tests silty samples which have different clay percentages were studied under different cyclic stress ratios. The results have showed that in soils having clay content equal to and less than 10%, the excess pore pressure ratio buildup was quicker with an increase in different cyclic stress ratios. When fine and clay content increases, excess pore water pressure decreases constant cyclic stress ratio in nonplastic silty soils. In addition, the applicability of the used criteria for the assessment of liquefaction susceptibility of fine grained soils is examined using laboratory test results.

  16. The cone penetration test in unsaturated silty sands

    Directory of Open Access Journals (Sweden)

    Yang Hongwei

    2016-01-01

    Full Text Available Very little is known about how to interpret the cone penetration test (CPT when performed in unsaturated soils. The few published studies on the CPT in unsaturated soils have focused on either clean sands or a silt. In this study new results of laboratory-controlled CPTs in an unsaturated silty sand are presented. The silty sand exhibits hydraulic hysteresis and suction hardening. Suction is observed to have a pronounced affect on measured cone penetration resistance. For an isotropic net confining stress of 60 kPa it is observed that higher suctions give rise to cone penetration resistances that are 50% larger than those for lower suctions. A semi-theoretical correlation is presented that links measured cone penetration resistances to initial relative density and mean effective stress. For this silty sand it is shown that failing to account for suction may result in significant overestimations and unsafe predictions of soil properties from measured cone penetration resistances.

  17. Analysis of behavior of melted dark green silty soil

    Institute of Scientific and Technical Information of China (English)

    Yiqun TANG; Ping YANG; Feng SHEN; Nianqing ZHOU

    2008-01-01

    The behavior of dark green silty soil of the 6th storey is studied by means of scanning electron micro-scopy (SEM). The shape, size and contact condition of the basic elements of the soil microstructure, and the shape and the size of the pore are further studied. In addi-tion, a comparative study is made to analyze the experi-ment results of Cu and dynamic test. The mechanic characteristics of common soil and those of melted soil are presented and their influences on dark silty soil after being frozen are theoretically illustrated from a micro-scopic perspective.

  18. Cadmium phytoextraction from loam soil in tropical southern China by Sorghum bicolor.

    Science.gov (United States)

    Wang, Xu; Chen, Can; Wang, Jianlong

    2017-06-03

    The cadmium (Cd) uptake characteristics by Sorghum bicolor cv. Nengsi 2# and Cowley from the acidic sandy loam soil (pH = 6.1) during the entire growth period (100 days) were investigated in pot outdoors in a tropical district of southern China, Hainan Island. The Cd-spiked levels in soil were set as 3 and 15 mg/kg. Correspondingly, the available Cd levels in soil extracted by Mehlich III solution were 2.71 and 9.41 mg/kg, respectively. Basically, two varieties in a full growth period (100 days) did not show a significant difference in their growth and Cd uptake. Under high Cd stress, the plant growth was inhibited and its biomass weight and height decreased by 38.7-51.5% and 27.6-28.5%, respectively. However, S. bicolor showed higher bioaccumulation capability of Cd from soil to plant [bioconcentration factor (BCF)>4], and higher transfer capability of Cd from roots to shoots [translocation factor (TF)>1] under high Cd stress; Cd contents in the roots, stems, and leaves of S. bicolor reached 43.79-46.07, 63.28-70.60, and 63.10-66.06 mg/kg, respectively. S. bicolor exhibited the potential phytoextraction capability for low or moderate Cd-contamination in acidic sandy loam soil.

  19. Linear Shrinkage Behaviour of Compacted Loam Masonry Blocks

    Directory of Open Access Journals (Sweden)

    NAWAB ALI LAKHO

    2017-04-01

    Full Text Available Walls of wet loam, used in earthen houses, generally experience more shrinkage which results in cracks and less compressive strength. This paper presents a technique of producing loam masonry blocks that are compacted in drained state during casting process in order to minimize shrinkage. For this purpose, loam masonry blocks were cast and compacted at a pressure of 6 MPa and then dried in shade by covering them in plastic sheet. The results show that linear shrinkage of 2% occurred which is smaller when compared to un-compacted wet loam walls. This implies that the loam masonry blocks compacted in drained state is expected to perform better than un-compacted wet loam walls.

  20. Hurricane Sandy and earthquakes

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  1. Analysis on Wetting Deformation Properties of Silty Clay

    Directory of Open Access Journals (Sweden)

    Xinrong Liu

    2014-06-01

    Full Text Available Changes in water level that cause deformation and stability problems often occur in foundation pit engineering. Water damage is one of the main problems that will lead to disasters in foundation pit engineering. Research findings with regard to properties of wetting deformation due to water damage can be applied not only in foundation pit engineering, slope engineering, hydraulic engineering, and mining engineering but also in related issues in the field of theoretical research and practice. In this study, the characteristics of silty clay deformation after wetting are examined from the perspective of the effect of wetting on the side wall of foundation pit, and wetting experiments on silty clay of a selected area’s stratum located in Chongqing Municipality are conducted under different confining pressures and stress levels through a multi-function triaxial apparatus. Then, laws of silty clay wetting deformation are obtained, and the relationship between wetting stress level and wetting deformation amount is also figured out. The study reveals that the maximum values of wetting deformation under different confining pressures have appear at a particular stress level; therefore, the related measures should be taken to avoid this deformation in the process of construction.

  2. The Effect of Soil Particle Arrangement on Shear Strength Behavior of Silty Sand

    Directory of Open Access Journals (Sweden)

    Nik Norsyahariati Nik Daud

    2016-01-01

    Full Text Available The presence of fines in sandy soil is recognized as a problem in geotechnical engineering. It is often assumed that the strength and liquefaction potential of a soil decreases with increasing fines content. Sand with a significant amount of fines is always encountered in geotechnical engineering projects. The main interest of this paper is to study the effect of particles arrangement and stress behaviour on sand and silty sand sample. The objectives are to determine the basic properties as well as the morphological and mineralogical properties and the relationship of those properties to the stress behaviour of the soils. Sand-silt mixtures with fines contents of 20% and 40% were prepared and a series of testing was carried out to determine their basic properties, morphological and thin section properties, and mechanical properties by using direct shear box equipment. Results show that the basic properties and morphological properties of soil affect the mechanical behaviour of soil. Shape of the soil particle can influence the packing of the soil, hence altering the mechanical behaviour of the soil. From the thin section, the soil is observed to be well graded and have a dense packing while the minerals observed were mainly quartz and rutile.

  3. Mobility of Arsenic and Heavy Metals in a Sandy-Loam Textured and Carbonated Soil

    Institute of Scientific and Technical Information of China (English)

    GARCIA; M.DIEZ; F.MARTIN; M.SIMóN; C.DORRONSORO

    2009-01-01

    The continued effect of the pyrite-tailing oxidation on the mobility of arsenic,lead,zinc,cadmium,and copper was studied in a carbonated soil under natural conditions,with the experimcntal plot preserved with a layer of tailing covering the soil during three years.The experimental area is located in Southern Spain and was affected by a pyrite-mine spill.The climate in the area is typically Mediterranean,which determines the rate of soil alteration and element mobility.The intense alteration processes that occurred in the soil during three years caused important changes in its morphology and a strong degradation of the main soil properties.In this period,lead concentrated in the first 5 mm of the soil,with concentrations higher than 1500 mg kg-1,mainly associated to the neoformation of plumbojarosite.Arsenic was partially leached from the first 5 mm and mainly concentrated between 5-10 mm in the soil,with maximum values of 1 239 mg kg-1;the retention of arsenates was related to the neoformation of iron hydroxysulfates (jarosite,schwertmannite) and oxyhydroxides (goethite,ferrihydrite),both with a variable degree of crystallinity.The mobility of Zn,Cd,and Cu was highly affected by pH,producing a stronger leaching in depth;their retention was related to the forms of precipitated aluminium and,in the case of Cu,also to the neoformation of hydroxysulfate.

  4. Clinoptilolite zeolite influence on inorganic nitrogen in silt loam and sandy agricultural soils

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral Clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4...

  5. Evaluation of Soil Quality Indicators in Sugarcane Management in Sandy Loam Soil

    Institute of Scientific and Technical Information of China (English)

    S.A.C.SANT'ANNA; M.F.FERNANDES; W.M.P.M.IVO; J.L.S.COSTA

    2009-01-01

    An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems.To select soil quality indicator variables in sugarcane (Saccharum offcinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination,ten composite soil samples (0-10 cm) were collected in July 2005 (rainy season) and again in March 2006 (dry season) from areas under cultivation of organic sugarcane (OS),green sugarcane (GS),burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo,Boca da Mata,Alagoas,Brazil.Microbial biomass-C (MBC),total organic C (TOC),soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis,mean weight diameter of water-stable soil aggregates (MWD),and percentage of water-stable macroaggregates (PWSA) were analyzed.Although MBC and TOC were higher in NF than in the cultivated areas,no differences were observed in these C pools between the three sugarcane systems.The response of FDA to the site management was dependent on the sampling time.In the rainy period,the activity followed the order:NF > OS > GS > BS,whereas in the dry season,only NF differed from the other treatments.Irrespective of the sampling time,MWD and PWSA decreased in the order NF > OS = GS > BS.The variables MWD and PWSA are quite sensitive for discriminating between site management histories regardless the sampling season.

  6. Eleven years' effect of conservation practices for temperate sandy loams: II. Soil pore characteristics

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Munkholm, Lars Juhl

    2017-01-01

    Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore characte......Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore......, the volume of pores > 30 μm was more than 0.03 m3 m-3 larger for MP than for D in spring 2014 at the 4- to 8-cm depth. At the 18- to 27-cm depth, direct drilling resulted in a better air permeability and pore continuity index (e.g., air permeability of 18.2 and 11.2 mm2 for D and MP, respectively at −10 k...

  7. Determination of Selenium Toxicity for Survival and Reproduction of Enchytraeid Worms in a Sandy Loam Soil

    Science.gov (United States)

    2016-07-01

    active radiation (PAR) light intensity of 12.8  0.7 µM m2/s (985  52 lux ), and mean temperature of 21.6  0.1 C. The soil moisture level was...PAR light intensity of 12.8  0.7 µM m2/s (985  52 lux ), and a mean temperature of 21.6  0.1 °C, for the duration of the 28 d test. The containers

  8. Effects of Nitramine Explosive CL-20 on the Soil Microinvertebrate Community in a Sandy Loam Soil

    Science.gov (United States)

    2013-09-01

    by individually combining and gently mixing CL-20- amended soil concentrates with clean SSL field soil in a plastic bag . This approach ensured that...Hawari, J.; Spain, J.C. Biodegradation of the Nitramine Explosive CL- 20. Appl. Environ. Microbiol. 2003, 69, 1871–1874. U.S. Department of

  9. Crop residues as driver for N2O emissions from a sandy loam soil

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Petersen, Søren O.; Chirinda, Ngonidzashe

    2017-01-01

    Nitrogen (N) cycling within agriculture constitutes a source of direct and indirect emissions of the potent greenhouse gas nitrous oxide (N2O). We analysed relationships between N2O emissions and C and N balances of four arable cropping systems under conventional or organic management within a long......-term experiment on a loamy sand soil at Foulum in Denmark. All cropping systems included winter wheat, a leguminous crop (faba bean or grass-clover), potato and spring barley grown in different 4-crop rotations varying in strategies for N supply (fertilizer/manure type and rate, use of catch crops and green...... manure). Crops in both organic and conventional systems received N at rates below the optimum for crop production. Soil N2O emissions were monitored in 2008–2009 in six selected crops which could be combined with data from other monitoring programs to calculate N2O emission factors for each of the 16...

  10. Soil resistance and resilience to mechanical stresses for three differently managed sandy loam soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per;

    2012-01-01

    carbon (CCC resistance and resilience of the three soils to compaction using air permeability (ka), void ratio (e) and air-filled porosity (ε) as functional indicators and to characterise aggregate stability, strength and friability. Aggregate tensile...... at both soil-water potentials than the MCC and CCC soils possibly due to higher biotic binding of soil particles by the greater organic carbon content. The water dispersible clay was negatively correlated with the level of clay saturation by organic carbon. The resistance of the soils to compaction......, quantified by both the compression index and a proposed functional index, was significantly greater for the MFC soil compared to the other two soils. The change in compression index with initial void ratio was significantly less for the MFC than the other soils. Plastic reorganisation of the soil particles...

  11. Olive Mill Effluent Spreading Effects on Water Retention of Tunisian Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    Hamdi SAHRAOUI

    2014-01-01

    Full Text Available Olive mill effluents (OME are characterized by their nutrients content and their adhesive and hydrophobic properties. An experiment was carried out at an olive growing area in Tunisia, “Sidi Bou Ali”, to identify the impact of spreading over OME on physical soil characteristics. Three treatments were in situ monitored, namely T0 (Control, T1 (25 m3/ha and T2 (50 m3/ha, over a period of 4 months. Measurements were conducted monthly corresponding respectively to D1, D2, D3 and D4. Water retention curves were established by a physical capillary model in porous medium. Results showed that the two applied OME doses induced a decrease in water retention, especially for potential matrixes above pF 2 corresponding to the water available range. No significant differences were found between the treated soil plots T1 and T2.doi:10.14456/WJST.2014.27

  12. Modeling Tractive Force Requirements of Wheel tractors For Disc Ploughing in Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    S O Nkakini

    2012-10-01

    Full Text Available Tractive force models at different tillage speeds were developed using dimensional analysis, describing the tractor tyre - soil interaction. In this research study, disc ploughing on an experimental plot at twenty different soil moisture levels in loamy sand soil was carried out using trace tractor techniques. The independent variables: drawbar pull force, rolling (motion resistance, wheel slip, moisture content, cone index, wheel numeric, contact pressure, speed, width of plough, depth of plough, and dependent variable (Tractive force were measured and compared to computed values. High coefficients of determination R2 = 0.9492, 0.9555 and 0.9447 for ploughing at tillage speeds of 1.94m/s, 2.22m/s and 2.5m/s were obtained respectively. Standard errors of 0.3672552, 0.8628 and 0.8047 and the percentage (% errors of -2.272608059 and 2.45655144,-2.304946155 and 2.523126085,-1.424947801 and 2.020155232 at minimum and maximum values, were obtained. These results are clear evidence of the test of goodness of fit of the models between predictive and measured parameters for ploughing at different tillage speeds. The models were verified and validated by comparing the predicted with the measured tractive forces, and shown to closely followed the experimental results.

  13. Predictivity strength of the spatial variability of phenanthrene sorption across two sandy loam fields

    DEFF Research Database (Denmark)

    Soares, Antonio; Paradelo Pérez, Marcos; Møldrup, Per

    2015-01-01

    Sorption is commonly suggested as the major process underlying the transport and fate of polycyclic aromatic hydrocarbons (PAHs) in soils. However, studies focusing in spatial variability at the field scale in particular are still scarce. In order to investigate the sorption of phenanthrene at th......). Other factors, such as the soil structure, available water content and the soil mineral fraction, might greatly influence the transport phenomenon, thus acting for important environmental repercussions....

  14. influence of tillage practices on physical properties of a sandy loam ...

    African Journals Online (AJOL)

    DR. AMINU

    Soil organic carbon (OC) and aggregate stability in water (MAW, ASC, DR and WSI) ... Key words: Tillage, Tillage systems, Soil Physical properties, Moisture storage, Physical quality ..... OC/organic matter contents of soils exerts great influe.

  15. Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil

    Science.gov (United States)

    Humin is the largest and also the least understood fraction of soil organic matter. The humin structure and its correlation with microbiological properties are particularly uncertain. We applied advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy to investigate the structural chan...

  16. Microstructure and stability of two sandy loam soils with different soil management

    NARCIS (Netherlands)

    Bouma, J.

    1969-01-01

    A practical problem initiated this study. In the Haarlemmermeer, a former lake reclaimed about 1850, several farmers had difficulties with soil structure. Land, plowed in autumn, was very wet in spring. Free water was sometimes present on the soil surface. Planting and seeding were long delayed in

  17. Estimation of the Potential for Atrazine Transport in a Silt Loam Soil

    Science.gov (United States)

    Eckhardt, D.A.V.; Wagenet, R.J.

    1996-01-01

    The transport potential of the herbicide atrazine (2-chloro-4-ethyl-6-isopropyl-s-triazine) through a 1-meter-thick root zone of corn (Zea mays L.) in a silty-loam soil in Kansas was estimated for a 22-year period (1972-93) using the one-dimensional water-flow and solute-transport model LEACHM. Results demonstrate that, for this soil, atrazine transport is directly related to the amount and timing of rain that follows spring applications of atrazine. Two other critical transport factors were important in wet years - [1] variability in atrazine application rate, and [2] atrazine degradation rates below the root zone. Results demonstrate that the coincidence of heavy rain soon after atrazine application can cause herbicide to move below the rooting zone into depths at which biodegradation rates are assumed to be low but are often unknown. Atrazine that reaches below the rooting zone and persists in the underlying soil can subsequently be transported into ground water as soil water drains, typically after the growing season. A frequency analysis of atrazine concentrations in subsurface drainage, combined with field data, demonstrates the relative importance of critical transport factors and confirms a need for definitive estimates of atrazine-degradation rates below the root zone. The analysis indicates that periodic leaching of atrazine can be expected for this soil when rainfall that exceeds 20 cm/mo coincides with atrazine presence in soil.

  18. Parameters of the occurrence of internal erosion processes in salty-sandy soils

    Directory of Open Access Journals (Sweden)

    Gajić Grozdana

    2005-01-01

    Full Text Available The study was aimed at defining the conditions of the occurrence of internal erosion in silty-sandy soils. The susceptibility of this soil to internal erosion depends on the porosity, particle-size composition and hydro-geo-mechanical parameters. Internal erosion stability was analyzed by the introduction of the coefficient of particle composition as the critical particle-size condition, which is in fact the coefficient of internal erosion (Kue. Based on the study results, mathematical models and the functional correlation between water regime and resistant characteristics of silty-sandy soils, we defined the parameters of the occurrence of initial internal erosion and analyzed the effects of the practical application of the study results.

  19. Parameters of the occurrence of internal erosion processes in salty-sandy soils

    OpenAIRE

    Gajić Grozdana

    2005-01-01

    The study was aimed at defining the conditions of the occurrence of internal erosion in silty-sandy soils. The susceptibility of this soil to internal erosion depends on the porosity, particle-size composition and hydro-geo-mechanical parameters. Internal erosion stability was analyzed by the introduction of the coefficient of particle composition as the critical particle-size condition, which is in fact the coefficient of internal erosion (Kue). Based on the study results, mathematical model...

  20. Modelling unfrozen water content in a silty clay permafrost deposit

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2011-01-01

    The mechanical properties of both unfrozen soils and permafrost soils are influenced by the amount of unfrozen water in the pore space. When dealing with foundation engineering in permafrost areas it is essential to estimate the unfrozen water content (wu). This paper deals with the establishing...... of a calibration equation for determining the unfrozen water content of a Greenlandic silty clay permafrost deposit. Calibration experiments have been conducted for water contents in the interval 0 – 10 % at both 5 °C and 22 °C. Calibration equations are verified against permittivity data from a permafrost core...... of material properties similar to the test soil. The calibration for 5°C is seen to make a good fit to the permafrost core data. Further experiments should be performed in order to extend the range of water contents tested and hence the range of validity of the calibration equation....

  1. The influence of land use and management on nitrogen leaching in two agricultural catchments in China and Denmark

    DEFF Research Database (Denmark)

    Manevski, Kiril

    -winter wheat annual systems at different fertilizer N rates in the North China Plain (NCP, silty loam soil), China, and (ii) maize for silage systems differing in past cropping, intercropping and fertilizer N levels in central Jutland (sandy loam soil, JB4) and southern Jutland (coarse sandy soil JB1, Jyndevad...

  2. Effect of silty sand with different sizes on corrosion behavior of 3Cr steel in CO2 aqueous environment

    Science.gov (United States)

    Liu, Wei; Lu, Songle; Zhang, Peng; Dou, Juanjuan; Zhao, Qinghe

    2016-08-01

    Corrosion behavior of 3Cr steel in CO2 aqueous environment containing silty sand was investigated by immersion test. The results show that CO2 corrosion rate and morphology of 3Cr steel were obviously affected by the size of silty sand. 5000 mesh silty sand mixed with corrosion products, forming compact Cr-rich corrosion scale and resulting in low corrosion rate and uniform corrosion. 1000 mesh silty sand mixed with corrosion products, forming porous corrosion scale without Cr enrichment and resulting in high corrosion rate and pitting corrosion. 5000 mesh silty sand enhanced Cr enrichment in corrosion scale, leading to low anodic current. However, 1000 mesh silty sand deteriorated Cr enrichment in corrosion scale, leading to high anodic current. Cathodic current was reduced by silty sand, but was not affected by two sizes of silty sand. Cr enrichment in corrosion scale of 3Cr steel was obviously affected by separation effect of silty sand.

  3. Analyzing Hurricane Sandy

    Science.gov (United States)

    Convertino, Angelyn; Meyer, Stephan; Edwards, Becca

    2015-03-01

    Post-tropical Storm Sandy underwent extratropical transition shortly before making landfall in southern New Jersey October 29 2012. Data from this system was compared with data from Hurricane Ike (2008) which represents a classic hurricane with a clear eye wall and symmetry after landfall. Storm Sandy collided with a low pressure system coming in from the north as the hurricane made landfall on the US East coast. This contributed to Storm Sandy acting as a non-typical hurricane when it made landfall. Time histories of wind speed and wind direction were generated from data provided by Texas Tech's StickNet probes for both storms. The NOAA Weather and Climate program were used to generate radar loops of reflectivity during the landfall for both storms; these loops were compared with time histories for both Ike and Sandy to identify a relationship between time series data and storm-scale features identified on radar.

  4. Measuring Static and Dynamic Properties of Frozen Silty Soils

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, M.D.

    1998-09-30

    A mechanical characterization of frozen silty soils has been conducted to support computer modeling of penetrators. The soils were obtained from the Eilson AFB (Alaska) vicinity. Quasi-static testing with a multiaxial system in a cold room and intermediate strain rate testing with a split Hopkinson pressure bar were conducted. Maximum stresses achieved were slightly above 1 GPa, apparently limiting the observed behavior primarily to elastic compression and pore crushing phenomena. Lower temperatures seem to increase the strength of the material markedly, although not by a simple factor. Lower temperatures and higher strain rates increase the apparent Young's and bulk moduli as well (an increase of {approximately} a factor of two is observed for strain rate increasing from 0.001 s{sup {minus}1} to 800 s{sup {minus}1}). The strength also depends strongly on strain rate. Increasing the strain rate from 0.001 {sup {minus}1} to 0.07 {sup {minus}1} increases the strength by a factor of five to ten (to values of order 1 GPa). However,only a small increase in strength is seen as strain rate is increased to {approximately} 10{sup 2}--10{sup 3} s{sup {minus}1}. The reliability of the strength measurements at strain rates< 1 s{sup {minus}1} is decreased due to details of the experimental geometry, although general trends are observable. A recipe is provided for a simulant soil based on bentonite, sand, clay-rich soil and water to fit the {approximately} 6% air-filled porosity, density and water content of the Alaska soils, based on benchtop mixing and jacketed compression testing of candidate mixes.

  5. Effect of silty sand in formation water on CO{sub 2} corrosion behavior of carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei, E-mail: weiliu@ustb.edu.cn; Dou, Juanjuan; Lu, Songle; Zhang, Peng; Zhao, Qinghe

    2016-03-30

    Graphical abstract: Silty sand (SiO{sub 2}) promoted the rapid heterogeneous nucleation of corrosion product (FeCO{sub 3}) and simultaneously decreased its grains growth. Silty sand mixed with corrosion product to form the outer layer of corrosion scale with high compactness, blocking the transport of ferrous ions and leading to the formation of the inner layer of corrosion scale without silty sand. The corrosion rate of carbon steel was obviously reduced due to the existence of silty sand in the outer layer by inhibiting anodic and cathodic currents. - Highlights: • CO{sub 2} corrosion rate of carbon steel was obviously reduced due to the existence of silty sand. • The corrosion scale containing silty sand inhibited anodic and cathodic currents, contributing to low corrosion rate. • A development mechanism of corrosion scale in silty sand containing CO{sub 2} environment was proposed. - Abstract: Corrosion behavior of carbon steel in CO{sub 2} aqueous environment containing silty sand was investigated using corrosion mass loss method, scanning electron microscopy (SEM), energy diffraction spectrum (EDS), and various electrochemical measurements. The results show that the corrosion rate of carbon steel was obviously reduced due to the existence of silty sand. Silty sand promoted the rapid heterogeneous nucleation of corrosion product FeCO{sub 3} and simultaneously decreased its grains growth. Silty sand mixed with corrosion product to form the outer layer of corrosion scale with high compactness, blocking the transport of ferrous ions and leading to the formation of the inner layer of corrosion scale without silty sand. The existence of silty sand in the outer layer of corrosion scale inhibited anodic and cathodic currents.

  6. Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

    Directory of Open Access Journals (Sweden)

    Yankai Wu

    2014-01-01

    Full Text Available Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil’s strength and improves the soil’s mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

  7. Liquefaction mitigation in silty soils using composite stone columns and dynamic compaction

    Institute of Scientific and Technical Information of China (English)

    T.Shenthan; R.Nashed; S.Thevanayagam; G. R. Martin

    2004-01-01

    The objective of this study is to develop an analytical methodology to evaluate the effectiveness ofvibro stone column (S.C.) and dynamic compaction (D.C.) techniques supplemented with wick drains to densify and mitigate liquefaction in saturated sands and non-plastic silty soils. It includes the following: (i) develop numerical models to simulate and analyze soil densification during S.C. installation and D.C. process, and (ii) identify parameters controlling post-improvement soil density in both cases, and (iii) develop design guidelines for densification of silty soils using the above techniques. An analytical procedure was developed and used to simulate soil response during S.C. and D.C. installations, and the results were compared with available case history data. Important construction design parameters and soil properties that affect the effectiveness of these techniques, and construction design choices suitable for sands and non-plastic silty soils were identified.The methodology is expected to advance the use of S.C. and D.C. in silty soils reducing the reliance on expensive field trials as a design tool. Thc ultimate outcome of this research will be design charts and design guidelines for using composite stone columns and composite dynamic compaction techniques in liquefaction mitigation of saturated silty soils.

  8. SHEARING AND WATER RETENTION BEHAVIOR OF UNSATURATED LOAM WITH MODELING

    Science.gov (United States)

    Kiyohara, Yukoh; Kazama, Motoki

    Unsaturated triaxial tests were carried out to study deformation behavior, effective stress path and water retention property of consolidated loam during consolidation and shearing processes. Initial matric suction was set as 0, 50, and 90 kPa, and confining pressures (net normal stresses) were set as 100 kPa. Then shearing processes were done under undrained and drained conditions. We clarified the relation between void ratio and Van Genuchten model parameter by using water retention curve. To predict the unsaturated shearing behavior, a modified Cam Clay model considering void ratio dependent Van Genuchten parameter was proposed. Those numerical test results were agreed well with laboratory tests results.

  9. Comportement au dégel des sols silteux Thaw Behavior in Silty Soils

    Directory of Open Access Journals (Sweden)

    Montarges R.

    2006-11-01

    Full Text Available Les problèmes géotechniques relatifs à l'offshore arctique concernent essentiellement le tassement et la dégradation mécanique des sols au dégel. Dans la perspective d'évaluation de l'importance de ces problèmes l'IFP, avec le concours du Laboratoire de Glaciologie et Géophysique de l'environnement, a entrepris en 1986-87, une étude méthodologique des sols au dégel. Deux sols silteux (un silt sableux et un silt argileux, de comportement au gel très différent, ont été utilisés pour cette étude préliminaire. L'interprétation des résultats obtenus, dans les domaines de la structure des sols gelés et de l'évolution de leurs caractéristiques mécaniques (tassement et résistance au cisaillement, montre l'influence prédominante de la présence des minéraux argileux. Les résultats de cette étude préliminaire sont brièvement examinés en terme d'application aux problèmes d'exploitation pétrolière en zones arctiques. La poursuite de l'expérimentation apparaît nécessaire notamment pour évaluer correctement l'incidence du comportement au dégel des sols sur la subsidence associée aux risques d'instabilité des conduites rigides ou flexibles. Geotechnical problems related to offshore arctic activities mainly concern the settling and mechanical degradation of soils as the result of thawing. In the outlook for assessing the importance of such problems, IFP, with the assistance of the Laboratoire de Glaciologie et Géophysique de l'Environnement, began methodological research in 1986-1987 on the effect of thawing on soils. Two silty soils (one sandy silt and one clayey silt having very different thaw behaviors were used for this preliminary study. The interpretation of the results obtained in the fields of frozen soil structure and the evolution of their mechanical properties (settling and shear strength shows the predominant influence of the presence of clayey minerals. The results of this preliminary study are examined

  10. Dynamic Characteristics of Saturated Silty Soil Ground Treated by Stone Column Composite Foundation

    Directory of Open Access Journals (Sweden)

    Yongxiang Zhan

    2014-01-01

    Full Text Available A shaking table model test was carried out to develop an understanding of the performance improvement of saturated silty soil ground using stone column composite foundation as reinforcement. It is found that at less than 0.161 g loading acceleration, soil between piles has not yet been liquefied, the response acceleration scarcely enlarges, and the shear displacement almost does not appear in silty soil. At 0.252 g loading acceleration, as a result of liquefaction of soil between piles, the response acceleration increases rapidly and reaches its peak, and the shear displacement of silty soil increases significantly. At 0.325 g loading acceleration, the integral rigidity of foundation decreases greatly, which reduces its capability of vibration transmission and result in the response acceleration amplification coefficient is less than that at the former loading acceleration, but the shear displacement of silty soil further increases. The stone column composite foundation can greatly reduce both the shear displacement and the settlement of ground compared with untreated foundation. Under the condition of 7-degree seismic fortification, the design meets seismic resistance requirements.

  11. Resistive heating enhanced soil vapor extraction of chlorinated solvents from trichloroethylene contaminated silty, low permeable soil

    NARCIS (Netherlands)

    Zutphen, M. van; Heron, G.; Enfield, C.G.; Christensen, T.H.

    1998-01-01

    A 2D-laboratory box experiment (12 x 56 x 116 cm) was conducted to simulate the enhancement of soil vapor extraction by the application of low frequency electrical heating Uoule heating) for the remediation of a low permeable, silty soil contaminated with trichloroethylene. Joule heating enlarged th

  12. Effects of Conventional and Conservation Tillage on Soil Hydraulic Properties of a Silty-loamy Soil

    DEFF Research Database (Denmark)

    Wahl, Niels Arne; Bens, O.; Buczko, U.

    2004-01-01

    a minimum macropore radius of 0.5 mm, range between 0.02% and 0.1%, about one order of magnitude lower than the figure obtained from visual inventarization. The results indicate a greater continuity and connectivity of the macropore system for silty soils with conservation tillage systems. Therefore...

  13. An experimental study on the relationship between acoustic parameters and mechanical properties of frozen silty clay

    Institute of Scientific and Technical Information of China (English)

    Xing Huang; DongQing Li; Feng Ming; JianHong Fang

    2013-01-01

    To study the influence of temperature and water content on ultrasonic wave velocity and to establish the relationship between ultrasonic wave velocity and frozen silty clay strength, ultrasonic tests were conducted to frozen silty clay by using RSM-SY5(T) nonmetal supersonic test meter, and the tensile strength and compressive strength of silty clay were measured under various negative temperatures. Test and analysis results indicate that, ultrasonic wave velocity rapidly changes in the temperature range of−1 °C to−5 °C. Ultrasonic wave velocity increased with an increase of water content until the water content reached the critical water content, while decreased with an increase of water content after the water content exceeded the critical water content. This study showed that there was strong positive correlation between the ul-trasonic wave velocity and the frozen soil strength. As ultrasonic wave velocity increased, either tensile strength or com-pressive strength increased. Based on the experimental data, the relationship between ultrasonic wave velocity and frozen silty clay strength was obtained through regression analysis. It was found that the ultrasonic test technique can be used to test frozen soils and lay the foundation for the determination of frozen soil strength.

  14. Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Terrestrial Plants in a Natural Sandy Loam Soil

    Science.gov (United States)

    2005-04-01

    TNB, RDX, HMX, and heavy metals to cucumber and radish. They determined that toxicity was mostly related to TNT and TNB, with a LOEC of 7 to 19 mg kg...species exposed to TNB, 2,4-DNT, and 2,6-DNT. Hormesis has been reported in plants exposed to heavy metals and aromatic hydrocarbons (Stebbing, 1982...Watermilfoil and duckweed ), and terrestrial plant species (i.e., yellow nutsedge, poplar, lettuce, and tall fescue (Schott and Worthley, 1974; Palazzo and

  15. Soil precompression stress, penetration resistance and crop yields in relation to differently-trafficked, temperate-region sandy loam soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Lamandé, Mathieu; Munkholm, Lars Juhl

    2016-01-01

    treatment (labelled M8-1), the soil was loaded only in the first year. A tricycle-like machine with a single pass of wide tyres each carrying 12 Mg (treatment S12) was included at one site. Traffic treatments were applied in a randomized block design with four replicates and with treatments repeated in four...... strength measure predicting resistance to subsoil compaction. The tyre inflation pressure and/or the mean ground pressure were the main predictors of PR in the upper soil layers. For deeper soil layers, PR correlated better to the wheel load. The number of wheel passes (M-treatments vs the S12 treatment......-pressure tyres by crab steering/dog-walk machinery....

  16. Nitrate leaching from sandy loam soils under a double-cropping forage system estimated from suction-probe measurements.

    NARCIS (Netherlands)

    Trindade, H.; Coutinho, J.; Beusichem, van M.L.; Scholefield, D.; Moreira, N.

    1997-01-01

    Nitrate leaching from a double-cropping forage system was measured over a 2-year period (June 1994–May 1996) in the Northwest region of Portugal using ceramic cup samplers. The crops were grown for silage making and include maize (from May to September) and a winter crop (rest of the year)

  17. Comparison of glyphosate and Roundup preparations influence on inorganic pyrophosphatase activity and available phosphorus content in sandy loam

    Directory of Open Access Journals (Sweden)

    Maciej Płatkowski

    2016-03-01

    Full Text Available The aim of the study was to compare the effect of glyphosate and its formulations: Roundup 360 SL (containing isopropylamine salt of glyphosate and polyethoxylated tallow amine and Roundup TransEnergy 450 SL (containing potassium salt of glyphosate and polyethoxylated ether amine on inorganic pyrophosphatase activity and available phosphorus content in soil. The experiment was carried out on loamy sand with organic carbon content 10.9 g·kg-1. Glyphosate and its salts amounts added to soil were: 0 (control, 1, 10, 100 mg·kg-1. Samples were adjusted to 60% maximum water capacity and they were incubated in temperature 20°C. Inorganic pyrophosphatase and available phosphorus content were measured on days 1, 7, 14, 28 and 56. The obtained results show that the observed effect of glyphosate and its formulations depended on the dosage and day of experiment. The largest changes of the measured parameters were observed after application of Roundup 360 SL – formulation containing glyphosate isopro­pylamine salt and polyethoxylated tallow amine. The positive statistically significant correlation between inorganic pyrophosphatase activity and available phosphorus content was reported only in soil treated with Roundup 360 SL.

  18. Quantity and nature of water-extractable organic matter from sandy loam soils with potato cropping managements

    Science.gov (United States)

    Water-extractable organic matter (WEOM) is part of the soil labile organic matter components. In this work, we evaluated the level and nature of soil WEOM from a long-term (6-year) potato crop rotation field experiment. The contents of water-extractable organic C (WEOC) were higher in continuous pot...

  19. Simultaneous hyperaccumulation of multiple heavy metals by Helianthus annuus grown in a contaminated sandy-loam soil.

    Science.gov (United States)

    Cutright, Teresa; Gunda, Nagaraju; Kurt, Firat

    2010-08-01

    Phytoremediation is a promising means for the treatment of contamination arising from heavy metal spills. Although several species have been identified as hyperaccumulators, most of the studies were performed with only one heavy metal. Experiments were conducted with two cultivars of H. annuus exposed to different combinations of metal contamination (30 mg/kg Cd, Cr, Ni, As, and/or Fe). Cultivar efficiency was based on total metal uptake, as well as translocation and selectivity of each metal. The results for each cultivar were also compared after 0.1 g/kg or 0.3 g/kg EDTA was added to enhance metal bioavailability. The key finding was that H. annuus achieved hyperaccumulator status for multiple metals simultaneously: Cd, Cr, and As.

  20. Toxicity of a New Polynitramine Energetic Material, CL-20, to the Enchytraeid Worm, Enchytraeus Crypticus, in a Sandy Loam Soil

    Science.gov (United States)

    2006-08-01

    due to photodecomposition, hydrolysis, reaction with organic matter, sorption/fixation, precipitation , immobilization, occlusion, microbial...ASTM Type II water, analytical reagent grade nitric acid 1% (volume/volume), then with ASTM Type I water. 2.3 Soil Amendment Procedures. Studies were...Initial reaction(s) in biotransformation of CL-20 is catalyzed by salicylate -l-monooxygenase from Pseudomonas sp. strain ATCC 29352. Appl. Environ

  1. Non-Linear finite element analysis of cone penetration in layered sandy loam soil-considering precompression stress state

    Science.gov (United States)

    Axisymmetric finite element (FE) method was developed using a commercial computer program to simulate cone penetration process in layered granular soil. Soil was considered as a non-linear elastic plastic material which was modeled using variable elastic parameters of Young’s Modulus and Poisson’s r...

  2. Study and Estimation of the Ratio of 137CS and 40K Specific Activities in Sandy and Loam Soils

    Directory of Open Access Journals (Sweden)

    Renata Mikalauskienė

    2011-12-01

    Full Text Available The present article describes changes in specific activities and fluctuations in the ratio of natural 40K and artificial 137Cs radionuclides in soil samples taken from different places of Lithuanian territory. The samples of soil have been selected from the districts polluted after the accident in Chernobyl nuclear plant performing nuclear testing operations. The study has established the main physical and chemical properties of soil samples and their impact on the concentration of 40K activities. 137Cs/40K specific activities in soil have been observed under the dry weight of the sample that varied from 0.0034 to 0.0240. The results of the study could be used for establishing and estimating 137Cs and 40K transfer in the system “soil-plant”.Article in Lithuanian

  3. Regional SOC inventory in the Belgian loam belt

    Science.gov (United States)

    Stevens, F.; Bogaert, P.; van Wesemael, B.

    2012-04-01

    Soil organic carbon (SOC) is the largest component of the terrestrial carbon pool and plays a vital role in the terrestrial carbon cycle. However, it remains a challenge to accurately quantify SOC dynamics in intensively cultivated landscapes. The general objective of the research is to improve the regional SOC dynamics by taking into account the lateral fluxes of sediments and carbon. The study focuses on the croplands of the Belgian loam belt. The first part of the project consists in constructing a 3-dimensional SOC map from soil profile description and ancillary environmental data. A georeferenced soil database provided soil profile description and analyses across the entire Belgian loam belt. A Monte Carlo method was used to account for the uncertainty in the reported SOC content of each horizon. Different methods permitting to construct continuous distribution of SOC density from bulk horizon measurements were compared. Properties that best characterized the erosion-accumulation pattern in the region were searched in the profile description database. Different topographic indices were computed from digital elevation models to assess the influence of the topography on the SOC distribution. A linear regression analysis was conducted in order to predict the SOC spatial distribution at different depth intervals from soil and terrain properties. Using the resulting model, maps of SOC and other soil properties at different depths, and representative of the situation in ~1960, will be constructed. The total uncertainty will be assessed and the main sources of uncertainty determined. These maps could be used as input data for a processed-based model coupling lateral fluxes of sediment and carbon turnover.

  4. Effect of Drainage Conditions on Cone Penetration Testing in Silty Soils

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2011-01-01

    This paper discusses the challenges that occur when performing Cone Penetration Tests (CPT) in silty soil due to changes in drainage conditions. In this paper, CPT results from various papers and researchers are collected and interpreted. Results from cone penetrations tests with various...... penetration rates is analysed, and it is shown how the changes in drainage condition, caused by the change in penetration rate, affects the plot in the soil classification charts. In addition, the effect on changes in penetration rate is compared for clay and silt, respectively, where the silty soil is more...... susceptible towards change in penetration rate. A normalized penetration rate is implemented in order to compare various cone resistance results, and hence investigate the changes from undrained to partially drained and from partially drained to fully drained....

  5. Improvement of Bearing Capacity of Shallow Foundation on Geogrid Reinforced Silty Clay and Sand

    Directory of Open Access Journals (Sweden)

    P. K. Kolay

    2013-01-01

    Full Text Available The present study investigates the improvement in the bearing capacity of silty clay soil with thin sand layer on top and placing geogrids at different depths. Model tests were performed for a rectangular footing resting on top of the soil to establish the load versus settlement curves of unreinforced and reinforced soil system. The test results focus on the improvement in bearing capacity of silty clay and sand on unreinforced and reinforced soil system in non-dimensional form, that is, BCR. The results show that bearing capacity increases significantly with the increased number of geogrid layers. The bearing capacity for the soil increases with an average of 16.67% using one geogrid layer at interface of soils with equal to 0.667 and the bearing capacity increases with an average of 33.33% while using one geogrid in middle of sand layer with equal to 0.33. The improvement in bearing capacity for sand underlain silty clay maintaining and equal to 0.33; for two, three and four number geogrid layer were 44.44%, 61.11%, 72.22%, respectively. The finding of this research work may be useful to improve the bearing capacity of soil for shallow foundation and pavement design for similar type of soil available elsewhere.

  6. Sandy PMO Disaster Relief Appropriations Act of 2013 Financial Data

    Data.gov (United States)

    Department of Homeland Security — Sandy PMO: Disaster Relief Appropriations Act of 2013 (Sandy Supplemental Bill) Financial Data. This is the Sandy Supplemental Quarterly Financial Datasets that are...

  7. Liquefaction Resistance of Chlef River Silty Sand: Effect of Low Plastic Fines and other Parameters

    Directory of Open Access Journals (Sweden)

    Tom Schanz

    2010-07-01

    Full Text Available Silty sands are the most common type of soil that could be involved in both staticand earthquake-induced liquefaction. Most of the recent earthquakes have revealed theliquefaction of silty sands. Therefore, the selection of the appropriate undrained residualshear strength of liquefied soils to be used in the assessment of the post-liquefactionstability of earth dams and other earth structures is becoming a major challenge. A seriesof undrained monotonic and cyclic triaxial tests were carried out on reconstituted saturatedsamples of sand with variation in the fines content ranging from 0 to 50% for themonotonic tests and from 0 to 40% for the cyclic ones, in order to study the influence offines fraction and other parameters on the undrained residual shear strength andliquefaction potential of loose, medium dense and dense silty sand samples (Dr = 12%,50%, 60% and 90%. The results of the monotonic tests show that the stress-strain responseand shear strength behaviour is controlled by the percentage of fines fraction and thesamples become contractive for the studied relative densities (Dr = 12% and 90%. The undrained residual shear strength decreases as the global void ratio decreases and thefines content increases up to 30% fines content. Beyond that, it decreases with increasingthe global void ratio and the fines content. Moreover, the undrained residual strengthdecreases linearly as the fines content and the inter-granular void ratio increase. Cyclictest results show that the increase of the fines fraction accelerates the liquefactionphenomenon for the studied amplitude and the liquefaction resistance decreases with theincrease of the global void ratio and the loading amplitude. We notice that the reduction inthe liquefaction resistance of Chlef sand-silt mixtures becomes very marked for the smallercyclic stress ratios CSR = 0.15 and 0.25.

  8. Hurricane Sandy Poster (October 29, 2012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

  9. Influence of Particle Shape on Drag Coefficient for Commonly Occuring Sandy Particles in Coastal Areas

    Directory of Open Access Journals (Sweden)

    Chitra Arora

    2010-06-01

    Full Text Available A well defined relationship connecting settling velocity with sediment geometry and ambient properties is an essential pre-requisite for coastal and hydraulic engineering studies. An established relationship for settling velocity of sandy particles assuming spherical shape geometry is available in the literature. In reality, the sediment particles need not be spherical at all times, which influences settling velocity that is strongly biased to the drag coefficient. Based on quantitative comparison with measured data collected at Oahu Islands located in the Hawaiian archipelago, USA this work provides a relationship between drag coefficient and particle shape factor for sand grains viz; sand, sandy loam and fine sandy loam typically found in coastal environment (typical size ranges from 0.05 to 2.0 mm. The particle Reynolds number and shape factor are evaluated for each grain. The drag coefficient evaluated as function of nominal diameter and Reynolds number show a positive correlation over a wide range of shape factors used in this study. A comprehensive correlation has been developed of the drag coefficient for non-spherical particles as a function of Reynolds number and particle shape. Further a regression analysis was performed on the functional dependence of drag coefficient on particle shape. Based on this study, it could be advocated the validity of Krumbien shape factor holds well for the above characterized grain size and various particle shapes considered. Hence, the settling velocity of particles has a functional dependence on estimated drag coefficient with important implications for modeling sediment transport and swash zone hydrodynamics.

  10. On Sandy Shores. Teacher's Guide.

    Science.gov (United States)

    Strang, Craig; And Others

    The activities in this guide (for grades 2-4) transport students to the sandy shore, one of the most fascinating ecosystems on the planet. At this ecological juncture a multiplicity of life forms find ways to survive, thrive, and interact with each other. Using a wide variety of learning formats, students explore and deepen their understanding of…

  11. Aging effect of 137Cs obtained from 137Cs in the Kanto loam layer from the Fukushima nuclear power plant accident and in the Nishiyama loam layer from the Nagasaki A-bomb explosion.

    Science.gov (United States)

    Ohta, Tomoko; Mahara, Yasunori; Kubota, Takumi; Igarashi, Toshifumi

    2013-01-01

    We measured (134)Cs and (137)Cs in the surface soil of the Kanto loam in the eastern Tokyo metropolitan area and the Nishiyama loam in Nagasaki, Japan. The observed (137)Cs deposition in the Kanto loam from the Fukushima nuclear power plant (NPP) accident ranged from 4.0 to 77 kBq m(-2), which corresponds to 0.3-5 times of that in the Nishiyama loam. The (137)Cs retardation factor in the Kanto loam obtained seven months after the Fukusima NPP accident and in the Nishiyama loam after 36 and 38 years from the detonation of the Pu atomic bomb (A-bomb) ranged from 180 to 260 and 2000 to 10,000, respectively. This difference in the retardation factors is attributed to an aging effect that corresponds to seven months and 36 to 38 years after the deposition of (137)Cs occurred on the soil minerals.

  12. Observation of microstructure of silty sand obtained from gelpush sampler and reconstituted sample

    Science.gov (United States)

    Yusa, Muhamad; Bowman, E. T.; Cubrinovski, Misko

    2017-06-01

    Observation of microstructure study of natural sand i.e. clean sand with fines (particles adjudged to be smaller than 75μm) content < 5% (Gel Push A) and silty sand with 35% fine content (Gel Push B) obtained by gel-push sampling was described. In addition, some observations from reconstituted samples prepared by dry pluviation and moist tamping were presented. Microstructures were investigated statistically by measuring particle orientation. It was evidence that natural sand (either gel push A and B) have a preferred orientation i.e. horizontally oriented. Similar particle orientation trend were observed by dry pluviated sample. Undisturbed and dry pluviated samples shows that they are anisotropic in terms of particles orientation. Moist tamped sample on the other hand, results in fairly random orientation with a slight bias towards vertical, thus does not replicate natural sand fabric.

  13. Determination of the equivalent intergranular void ratio - Application to the instability and the critical state of silty sand

    Science.gov (United States)

    Nguyen, Trung-Kien; Benahmed, Nadia; Hicher, Pierre-Yves

    2017-06-01

    This paper presents an experimental study of mechanical response of natural Camargue silty sand. The analysis of test results used the equivalent intergranular void ratio instead of the global void ratio. The calculation of equivalent intergranular void ratio requires the determination of parameter b which represents, physically, the fraction of active fines participating on the chain forces network, hence the strength of the soil. A new formula for determining the parameter b by using an approach based on the coordination number distribution and probability calculation is proposed. The validation of the developed relationship was done through back-analysis of published datasets in literature on the effect of fines content on silty sand behavior. It is shown that the equivalent intergranular void ratio calculated with the b value obtained by the new formula is able to provide strong correlation to not only the critical state of but also the onset of instability of various silty sands, in different terms as peak deviator stress, peak stress ratio or cyclic resistance. Therefore, it is suggested that the use of the equivalent void ratio concept and the new b calculating formula is highly desirable in predicting of the silty sand behavior.

  14. Determination of the equivalent intergranular void ratio - Application to the instability and the critical state of silty sand

    Directory of Open Access Journals (Sweden)

    Nguyen Trung-Kien

    2017-01-01

    Full Text Available This paper presents an experimental study of mechanical response of natural Camargue silty sand. The analysis of test results used the equivalent intergranular void ratio instead of the global void ratio. The calculation of equivalent intergranular void ratio requires the determination of parameter b which represents, physically, the fraction of active fines participating on the chain forces network, hence the strength of the soil. A new formula for determining the parameter b by using an approach based on the coordination number distribution and probability calculation is proposed. The validation of the developed relationship was done through back-analysis of published datasets in literature on the effect of fines content on silty sand behavior. It is shown that the equivalent intergranular void ratio calculated with the b value obtained by the new formula is able to provide strong correlation to not only the critical state of but also the onset of instability of various silty sands, in different terms as peak deviator stress, peak stress ratio or cyclic resistance. Therefore, it is suggested that the use of the equivalent void ratio concept and the new b calculating formula is highly desirable in predicting of the silty sand behavior.

  15. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    WAHYU ASTIKO

    2016-01-01

    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  16. Water flow and nutrient transport in a layered silt loam soil

    NARCIS (Netherlands)

    Vos, de J.A.

    1997-01-01


    Theory, numerical models, and field and laboratory measurements are used to describe and predict water flow and nutrient transport in a layered silt loam soil. One- and two-dimensional models based on the Darcy equation for water flow and the convection-dispersion equation for solute

  17. New way of measurement of thermophysical properties of clay loam materials by transient methods

    Science.gov (United States)

    Boháč, Vlastimil; Dieška, Peter; Vretenár, Viliam; Lukáč, Vladimír

    2016-07-01

    The problem of the measurement of clay loam materials in plastic consistency is more or less difficult as they can change the shape during the long time measurements. The specimen thickness is expected as the constant during all the experiment measured by transient pulse method. In a case of plastic clay loam, it can change the form during the measurement because of the squeeze of the material even under the gravity condition. Thus the specimen surface wall should be reinforced by special dimensionally well-defined thin wall container. In this paper the special container in a form of thin tube rings bounded by central annular ring was constructed and used for the measurements. The heat source was inserted into the tube rings through the nozzle in the middle part and the thermocouple was inserted through the drilled openings at defined distance from the heat source. System clamped the heat source together with the rings at desired distance from the thermocouple. This distance represents the thickness of tested specimen. The soft plastic material fill the inner space of tube rings in such a way to fulfill the geometry conditions for this method. The need of soft clay loam material measurement is to test its thermal properties because of the interest to use it as the heat storage material below the buildings. The measured clay loam containing some moisture has quite high values of specific heat and thus the use of it as the heat storage material is promising.

  18. Influence of wood-derived biochar on the compactibility and strength of silt loam soil

    Science.gov (United States)

    Ahmed, Ahmed; Gariepy, Yvan; Raghavan, Vijaya

    2017-04-01

    Biochar is proven to enhance soil fertility and increase crop productivity. Given that the influence of biochar on soil compaction remains unclear, selected physico-mechanical properties of soil amended with wood-derived biochar were assessed. For unamended silt loam, the bulk density, maximum bulk density, optimum moisture content, plastic limit, liquid limit, and plasticity index were 1.05 Mg m-3, 1.69 Mg m-3, 16.55, 17.1, 29.3, and 12.2%, respectively. The penetration resistance and shear strength of the unamended silt loam compacted in the standard compaction Proctor mold and at its optimum moisture content were 1800 kPa and 850 kPa, respectively. Results from amending the silt loam with 10% particle size ranges (0.5-212 μm) led to relative decreases of 18.1, 17.75, 66.66, and 97.4% in bulk density, maximum bulk density, penetration resistance, and shear strength, respectively; a 26.8% relative increase in optimum moisture content; along with absolute increases in plastic limit, liquid limit, and plasticity index of 5.3, 13.7, and 8.4%, respectively. While the biochar-amended silt loam soil was more susceptible to compaction, however, soil mechanical impedance enhanced.

  19. Evaluation of pedotransfer functions for estimating the soil water retention points

    Science.gov (United States)

    Bahmani, Omid; Palangi, Sahar

    2016-06-01

    Direct measurement of soil moisture has been often expensive and time-consuming. The aim of this study was determining the best method to estimate the soil moisture using the pedotransfer functions in the soil par2 model. Soil samples selected from the database UNSODA in three textures include sandy loam, silty loam and clay. In clay soil, the Campbell model indicated better results at field capacity (FC) and wilting point (WP) with RMSE = (0.06, 0.09) and d = (0.65, 0.55) respectively. In silty loam soil, the Epic model had accurate estimation with MBE = 0.00 at FC and Campbell model had the acceptable result of WP with RMSE = 0.03 and d = 0.77. In sandy loam, Hutson and Campbell models had a better result to estimation the FC and WP than others. Also Hutson model had an acceptable result to estimation the TAW (Total Available Water) with RMSE = (0.03, 0.04, 0.04) and MBE = (0.02, 0.01, 0.01) for clay, sandy loam and silty loam, respectively. These models demonstrate the moisture points had the internal linkage with the soil textures. Results indicated that the PTFs models simulate the agreement results with the experimental observations.

  20. [Effects of soil texture and water content on the mineralization of soil organic carbon in paddy soils].

    Science.gov (United States)

    Sun, Zhong-lin; Wu, Jin-shui; Ge, Ti-da; Tang, Guo-yong; Tong, Cheng-li

    2009-01-01

    To understand how soil texture and water content affect the mineralization of organic C in paddy soil, 3 selected soils (sandy loam, clay loam, and silty clay) were incubated (25 degrees C) with 14 C-labelled rice straw (1.0 g x kg(-1)) at water content varied from 45% to 105% of water holding capacity (WHC). Data indicated that, in the sandy loam and clay loam, the mineralization rate of 14 C-labelled rice straw reached the maximum at 75% WHC, as 53% and 58% of the straw C mineralized in the incubation period of 160 d, whereas in the silty clay, it increased gradually (from 41.8% to 49.0%) as water content increased up to 105% WHC. For all of the three soils, the mineralization rate of soil native organic C reached the maximum at 75% WHC, with 5.8% of the organic C mineralized in the same period for the sandy loam, and 8.0% and 4.8% for the clay loam and silty clay, respectively. As water content increased further, the mineralization rate of native organic C in the three soils significantly declined. The mineralization rate of added rice straw and native organic C in all the three soils, was well fitted with a conic curve. These results suggest that water-logging can decrease the mineralization of organic C in paddy soils.

  1. IMPLEMENTASI SANDI HILL UNTUK PENYANDIAN CITRA

    Directory of Open Access Journals (Sweden)

    JJ Siang

    2002-01-01

    Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

  2. Risk assessment of gas oil and kerosene contamination on some properties of silty clay soil.

    Science.gov (United States)

    Fallah, M; Shabanpor, M; Zakerinia, M; Ebrahimi, S

    2015-07-01

    Soil and ground water resource pollution by petroleum compounds and chemical solvents has multiple negative environmental impacts. The aim of this research was to investigate the impacts of kerosene and gas oil pollutants on some physical and chemical properties, breakthrough curve (BTC), and water retention curve (SWRC) of silty clay soil during a 3-month period. Therefore, some water-saturated soils were artificially contaminated in the pulse condition inside some glassy cylinders by applying half and one pore volume of these pollutants, and then parametric investigations of the SWRC were performed using RETC software for Van Genukhten and Brooks-Corey equations in the various suctions and the soil properties were determined before and after pollution during 3 months. The results showed that gas oil and kerosene had a slight effect on soil pH and caused the cumulative enhancement in the soil respiration, increase in the bulk density and organic matter, and reduction in the soil porosity and electrical and saturated hydraulic conductivity. Furthermore, gas oil retention was significantly more than kerosene (almost 40%) in the soil. The survey of SWRC indicated that the contaminated soil samples had a little higher amount of moisture retention (just under 15% in most cases) compared to the unpolluted ones during this 3-month period. The parametric analysis of SWRC demonstrated an increase in the saturated water content, Θ s, from nearly 49% in the control sample to just under 53% in the polluted ones. Contaminants not only decreased the residual water content, Θ r, but also reduced the SWRC gradient, n, and amount of α parameter. The evaluation of both equations revealed more accurate prediction of SWRC's parameters by Van Genukhten compared to those of Brooks and Corey.

  3. Flume experiments of deposition rate on foreset of silty delta relative to hydrographic patterns

    Institute of Scientific and Technical Information of China (English)

    SUZUKI Taro; ENDO Noritaka

    2011-01-01

    Foreset profiles of deltaic topography change corresponding to hydraulic conditions, and are influenced by water discharge and change rates of water discharge. To investigate the correlation between the transition of deposition rates on the foreset and the change rate of water discharge of temporary waxing and subsequent waning lfows, we perform experiments on silty deltas that developed under several different hydrographic patterns. The ifndings are as follows: (1) Under lfows with constant discharge, the deposition rate on the foreset was low at high water discharge and high at low water discharge because the separated lfow became vigorous at high water discharge and prevented sediment supply onto the foreset. If the water discharge is not constant, the deposition rate shifted concurrently with water discharge only at extremely low change rate. (2i) In a waxing lfow at low (but not extremely low) increase rate, the deposition rate gradually decreased with some time lag. (2ii) In the case of high increase discharge, intense erosion on the topset caused by rapid waxing made a large amount of silt move onto the foreset and the deposition rate temporary increased. (3) With ample time after waning stage, the deposition rate recovered to that at constant low water discharge in all runs. However, the transitional processes depended on not only waning rate but also waxing rate at before waning stage. (3i) In the case of high decrease rate of water discharge, the deposition rate abruptly decreased regardless of increase rate. (3ii) Even in the case of low decrease rate of water discharge, if the increase rate before waning stage was high, the deposition rate abruptly decreased. (3iii) Only in the case where both the increase rate and the decrease rate were low, deposition rate gradually increased.

  4. Feasibility of on-site bioremediation of loam soil contaminated by diesel oil.

    Science.gov (United States)

    Rubin, H; Narkis, N

    2001-09-01

    This study originated from an accidental event of diesel oil contamination in a loam soil area of 7,000 m2. Approximately a volume of 1,300 m3 of diesel oil was released into the environment. Reclamation of the contaminated soil by on-site bioremediation was selected as the most appropriate treatment method. A major concern was associated with the nature of the local loam soil. Loam has a very low hydraulic conductivity and very quickly becomes impermeable after its contact with water. The bioremediation approach incorporated excavation of the contaminated soil, mixing it with an agent, which increased its permeability. Following this preliminary treatment came the construction of bioreactors as a suitable environment of nutrients, moisture, dissolved oxygen, and enriched culture of microorganisms, which enabled breakdown of the diesel oil. This case study indicated that the target of 99% of diesel oil clean up could be achieved by using the technology of on-site bioremediation. The selected treatment method was found to be technologically and economically feasible. However, some improvement in the application of the basic treatment approach might increase the bioremediation efficiency.

  5. EAARL Coastal Topography-Sandy Hook 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface/bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Gateway National Recreation Area's Sandy Hook Unit in New Jersey...

  6. Heterotrophic bacterial populations in tropical sandy beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; LokaBharathi, P.A.

    Distribution pattern of heterotrophic bacterial flora of three sandy beaches of the west coast of India was studied. The population in these beaches was microbiologically different. Population peaks of halotolerant and limnotolerant forms were...

  7. Gas entrapment and microbial N2O reduction reduce N2O emissions from a biochar-amended sandy clay loam soil

    Science.gov (United States)

    Harter, Johannes; Guzman-Bustamante, Ivan; Kuehfuss, Stefanie; Ruser, Reiner; Well, Reinhard; Spott, Oliver; Kappler, Andreas; Behrens, Sebastian

    2016-12-01

    Nitrous oxide (N2O) is a potent greenhouse gas that is produced during microbial nitrogen transformation processes such as nitrification and denitrification. Soils represent the largest sources of N2O emissions with nitrogen fertilizer application being the main driver of rising atmospheric N2O concentrations. Soil biochar amendment has been proposed as a promising tool to mitigate N2O emissions from soils. However, the underlying processes that cause N2O emission suppression in biochar-amended soils are still poorly understood. We set up microcosm experiments with fertilized, wet soil in which we used 15N tracing techniques and quantitative polymerase chain reaction (qPCR) to investigate the impact of biochar on mineral and gaseous nitrogen dynamics and denitrification-specific functional marker gene abundance and expression. In accordance with previous studies our results showed that biochar addition can lead to a significant decrease in N2O emissions. Furthermore, we determined significantly higher quantities of soil-entrapped N2O and N2 in biochar microcosms and a biochar-induced increase in typical and atypical nosZ transcript copy numbers. Our findings suggest that biochar-induced N2O emission mitigation is based on the entrapment of N2O in water-saturated pores of the soil matrix and concurrent stimulation of microbial N2O reduction resulting in an overall decrease of the N2O/(N2O + N2) ratio.

  8. Influence of 20-year organic and inorganic fertilization on organic carbon accumulation and microbial community structure of aggregates in an intensively cultivated sandy loam soil.

    Directory of Open Access Journals (Sweden)

    Huanjun Zhang

    Full Text Available To evaluate the long-term effect of compost (CM and inorganic fertilizer (NPK application on microbial community structure and organic carbon (OC accumulation at aggregate scale, soils from plots amended with CM, NPK and no fertilizer (control for 20 years (1989-2009 were collected. Soil was separated into large macroaggregate (>2,000 μm, small macroaggregate (250-2,000 μm, microaggregate (53-250 μm, silt (2-53 μm and clay fraction (<2 μm by wet-sieving, and their OC concentration and phospholipid fatty acids (PLFA were measured. The 20-year application of compost significantly (P<0.05 increased OC by 123-134% and accelerated the formation of macroaggregates, but decreased soil oxygen diffusion coefficient. NPK mainly increased OC in macroaggregates and displayed weaker influence on aggregation. Bacteria distributed in all aggregates, while fungi and actinobacteria were mainly in macroaggregates and microaggregates. The ratio of monounsaturated to branched (M/B PLFAs, as an indicator for the ratio of aerobic to anaerobic microorganisms, increased inversely with aggregate size. Both NPK and especially CM significantly (P<0.05 decreased M/B ratios in all aggregates except the silt fraction compared with the control. The increased organic C in aggregates significantly (P<0.05 negatively correlated with M/B ratios under CM and NPK. Our study suggested that more efficient OC accumulations in aggregates under CM-treated than under NPK-treated soil was not only due to a more effective decrease of actinobacteria, but also a decrease of monounsaturated PLFAs and an increase of branched PLFAs. Aggregations under CM appear to alter micro-habitats to those more suitable for anaerobes, which in turn boosts OC accumulation.

  9. Community structure of ammonia-oxidizing bacteria under long-term application of mineral fertilizer and organic manure in a sandy loam soil.

    Science.gov (United States)

    Chu, Haiyan; Fujii, Takeshi; Morimoto, Sho; Lin, Xiangui; Yagi, Kazuyuki; Hu, Junli; Zhang, Jiabao

    2007-01-01

    The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the alpha subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils.

  10. Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Hansen, Jørgen Frederik; Kjellerup, Viggo K.;

    1993-01-01

    the cumulative loss of nitrate to increase significantly. More nitrate was leached after application of slurry because organic nitrogen in the slurry was mineralized. With IN (CAN) the leaching losses of nitrate were in the following order: continuous spring barley undersown with Italian ryegrass

  11. Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

    Directory of Open Access Journals (Sweden)

    Leila Esmaeelnejad

    2016-06-01

    Full Text Available In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C from two feedstocks (rice husk and apple wood chips. Produced biochars were prepared at two diameters (1-2 mm and <1 mm and mixed with soil at a rate of 2% (w/w. Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks.

  12. Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeelnejad, L.; Shorafa, M.; Gorji, M.; Hosseini, S.M.

    2016-11-01

    In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C) from two feedstocks (rice husk and apple wood chips). Produced biochars were prepared at two diameters (1-2 mm and <1 mm) and mixed with soil at a rate of 2% (w/w). Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks) was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks. (Author)

  13. Peanut plant growth and yield as influenced by co-inoculation with Bradyrhizobium and some rhizo-microorganisms under sandy loam soil conditions

    National Research Council Canada - National Science Library

    Badawi, F.Sh.F; Biomy, A.M.M; Desoky, A.H

    2011-01-01

    ... known N 2 -fixing plant-microorganism interactions is the legume–rhizobia symbiosis, which is considered the most efficient and important process in crop production, so as to improve soil fertility and farming system flexibility ( Mylona et al., 1995 ). Numerous publications have indicated the necessity of legume inoculation with effective and effi...

  14. Arbuscular mycorrhizal fungus enhances P acquisition of wheat (Triticum aestivum L.) in a sandy loam soil with long-term inorganic fertilization regime.

    Science.gov (United States)

    Hu, Junli; Lin, Xiangui; Wang, Junhua; Cui, Xiangchao; Dai, Jue; Chu, Haiyan; Zhang, Jiabao

    2010-10-01

    The P efficiency, crop yield, and response of wheat to arbuscular mycorrhizal fungus (AMF) Glomus caledonium were tested in an experimental field with long-term (19 years) fertilizer management. The experiment included five fertilizer treatments: organic amendment (OA), half organic amendment plus half mineral fertilizer (1/2 OM), mineral fertilizer NPK, mineral fertilizer NK, and the control (without fertilization). AMF inoculation responsiveness (MIR) of wheat plants at acquiring P were estimated by comparing plants grown in unsterilized soil inoculated with G. caledonium and in untreated soil containing indigenous AMF. Without AMF inoculation, higher crop yields but lower colonization rates were observed in the NPK and two OA-inputted treatments, and NPK had significantly (P soils and thereby P acquisition of wheat plants compared with OA and 1/2 OM. G. caledonium inoculation significantly (P soil alkaline phosphatase (ALP) activity, only with the NPK treatment. This gave an MIR of ca. 45% on total P acquisition of wheat plants. There were no other remarkable MIRs. It suggested that the MIR is determined by soil available P status, and rational combination of AMF with chemical NPK fertilizer can compensate for organic amendments by improving P-acquisition efficiency in arable soils.

  15. Effect of Simulated Weathering and Aging of TNT in Amended Sandy Loam Soil on Toxicity to the Enchytraeid Worm, Enchytreaeus Crypticus

    Science.gov (United States)

    2006-05-01

    Carlton T. Phillips Jan E. Kolakowski Carl W. Kurnas RESEARCH AND TECHNOLOGY DIRECTORATE May 2006 20060828026 Approved for public release; distribution is...pp 2365-2370. Haley, M.V.; Checkai, R.T.; Kurnas , C.W.; Wentsel, R.S.; Nwanguma, R.O.; Sadusky, M. 1993. Toxicity determination of explosive...M.; Phillips, C.T.; Kolakowski, J.E.; Kurnas C.W.; Sunahara, G.I. 2003. Survival and reproduction of Enchytraeus crypticus (Oligochaeta

  16. Influence of 20-year organic and inorganic fertilization on organic carbon accumulation and microbial community structure of aggregates in an intensively cultivated sandy loam soil.

    Science.gov (United States)

    Zhang, Huanjun; Ding, Weixin; He, Xinhua; Yu, Hongyan; Fan, Jianling; Liu, Deyan

    2014-01-01

    To evaluate the long-term effect of compost (CM) and inorganic fertilizer (NPK) application on microbial community structure and organic carbon (OC) accumulation at aggregate scale, soils from plots amended with CM, NPK and no fertilizer (control) for 20 years (1989-2009) were collected. Soil was separated into large macroaggregate (>2,000 μm), small macroaggregate (250-2,000 μm), microaggregate (53-250 μm), silt (2-53 μm) and clay fraction (soil oxygen diffusion coefficient. NPK mainly increased OC in macroaggregates and displayed weaker influence on aggregation. Bacteria distributed in all aggregates, while fungi and actinobacteria were mainly in macroaggregates and microaggregates. The ratio of monounsaturated to branched (M/B) PLFAs, as an indicator for the ratio of aerobic to anaerobic microorganisms, increased inversely with aggregate size. Both NPK and especially CM significantly (Psoil was not only due to a more effective decrease of actinobacteria, but also a decrease of monounsaturated PLFAs and an increase of branched PLFAs. Aggregations under CM appear to alter micro-habitats to those more suitable for anaerobes, which in turn boosts OC accumulation.

  17. Penetration grouting reinforcement of sandy gravel

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; PENG Zhen-bin; TANG Yi-qun; PENG Wen-xiang; HE Zhong-ming

    2008-01-01

    To study the relationship between grouting effect and grouting factors, three factors (seven parameters) directionless pressure and small cycle grouting model experiment on sandy gravel was done, which was designed according to uniform design method. And regressing was applied to analysis of the test data. The two models test results indicate that when the diffusing radius of grout changes from 26 to 51 era, the grouted sandy gravel compressing strength changes fTom 2.13 to 12.30 MPa; the relationship between diffusing radius(R) and water cement ratio(m), permeability coefficient(k), grouting pressure(p), grouting time(t) is R=19.953m0.121k0.429p0.412t0.437, the relationship between compressing strength(P) and porosity(n), water cement ratio, grouting pressure, grouting time is P=0.984n0.517m-1.488p0.118t0.031.So the porosity of sandy gravel, the permeability coefficient of sandy gravel, grouting pressure, grouting time, water cement ratio are main factors to influence the grouting effect. The grouting pressure is the main factor to influence grouting diffusing radius, and the water cement ratio is the main factor to influence grouted sandy gravel compressing strength.

  18. Long-term effects of grass-clover ley on the structure of a silt loam soil in a cold temperate climate

    Science.gov (United States)

    Jarvis, Nicholas; Koestel, John; Larsbo, Mats; Taylor, Astrid; Kätterer, Thomas

    2016-04-01

    Soil pore space structure is mediated by interacting biological and physical processes that can be strongly affected by land use or management change. The objective of this study was to investigate the long-term effects of grass-clover leys on the structure of a silt loam soil in a cold humid climate. The measurements were made in a long-term field trial established in 1956 at Offer in northern Sweden. This experiment includes four treatments with varying proportions of ley (1, 2, 3 or 5 years) in a 6-year forage-based rotation. We used X-ray tomography to quantify topsoil structural pore networks in the first year of arable cropping following the ley break, a few weeks after sowing in spring. Near-saturated infiltration was also measured as a proxy for soil structure in both topsoil and subsoil. Earthworm populations were quantified by both hand-digging and infiltration of mustard solution. In the topsoil, the treatments with a greater proportion of ley in the rotation had larger organic carbon contents, near-saturated hydraulic conductivity and earthworm biomass as well as smaller bulk densities and larger total porosities. In contrast, no treatment effects were found for the volume, size distribution, connectivity and heterogeneity of the X-ray imaged pore space. Topsoil structure is seasonally dynamic and it seems possible that significant effects of long-term cropping treatments on the architecture of these larger pore networks (image resolution of 65 microns) would have been found later in the season, as a result of the re-establishment of earthworm biopores after tillage. No individuals of deep-burrowing anecic earthworm species were found at the site. Previous work has also showed shallow rooting at this site, with almost all visible roots of spring barley confined to the uppermost 30 cm. Thus, it is perhaps not surprising that no effects of crop treatment on organic carbon content were found in the subsoil. Likewise, there were no apparent treatment

  19. [Simulation alfalfa growth in Wulanbuhe sandy region].

    Science.gov (United States)

    Bai, Wenming; Bao, Xuemei

    2002-12-01

    Based on the theories of accumulated temperature and on the physio-ecological characteristics of Medicago sativa, a simulation model for its growth under soil water stress in arid sandy region was developed. The model was mainly composed of four modules: the stage module of growth, the dynamic module of leaf area index, the accumulated module of dry matter, and the distributive module of dry matter. After simulating and calculating, the model could be used to predict the growing progress and dynamic changes of leaf area and yield for herbage in sandy region. The result shows that the application of the model to production is usually effective.

  20. Implications of Fecal Bacteria Input from Latrine-Polluted Ponds for Wells in Sandy Aquifers

    Science.gov (United States)

    Knappett, Peter S. K.; McKay, Larry D.; Layton, Alice; Williams, Daniel E.; Alam, Md. J.; Huq, Md. R.; Mey, Jacob; Feighery, John E.; Culligan, Patricia J.; Mailloux, Brian J.; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S.; Ahmed, Kazi M.; van Geen, Alexander

    2012-01-01

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5-1.3 log10/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater. PMID:22191430

  1. Implications of fecal bacteria input from latrine-polluted ponds for wells in sandy aquifers.

    Science.gov (United States)

    Knappett, Peter S K; McKay, Larry D; Layton, Alice; Williams, Daniel E; Alam, Md J; Huq, Md R; Mey, Jacob; Feighery, John E; Culligan, Patricia J; Mailloux, Brian J; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S; Ahmed, Kazi M; van Geen, Alexander

    2012-02-07

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5 to 1.3 log(10)/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence the how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater.

  2. Predicting the Grouting Ability of Sandy Soils by Artificial Neural Networks Based On Experimental Tests

    Directory of Open Access Journals (Sweden)

    Mahmoud Hassanlourad

    2014-12-01

    Full Text Available In this paper, the grouting ability of sandy soils is investigated by artificial neural networks based on the results of chemical grout injection tests. In order to evaluate the soil grouting potential, experimental samples were prepared and then injected. The sand samples with three different particle sizes (medium, fine, and silty and three relative densities (%30, %50, and %90 were injected with the sodium silicate grout with three different concentrations (water to sodium silicate ratio of 0.33, 1, and 2. A multi-layer Perceptron type of the artificial neural network was trained and tested using the results of 138 experimental tests. The multi-layer Perceptron included one input layer, two hidden layers and one output layer. The input parameters consisted of initial relative densities of grouted samples, the average size of particles (D50, the ratio of the grout water to sodium silicate and the grout pressure. The output parameter was the grout injection radius. The results of the experimental tests showed that the radius of grout injection is a complicated function of the mentioned parameters. In addition, the results of the trained artificial neural network showed to be reasonably consistent with the experimental results.

  3. Interstitial meiofauna of Namib sandy beaches

    African Journals Online (AJOL)

    1988-03-16

    Mar 16, 1988 ... sandy beaches on the Namibian coast, Langstrand and Cape Cross. A transverse ... prominent in the mid-shore at Cape Cross but occurred in low numbers at Langstrand , where archiannelids ... Koop (1983) recorded the faunal composition of local .... four replicate sediment cores were taken at 15 cm.

  4. Bibliography of sandy beaches and sandy beach organisms on the African continent

    CSIR Research Space (South Africa)

    Bally, R

    1986-01-01

    Full Text Available This bibliography covers the literature relating to sandy beaches on the African continent and outlying islands. The bibliography lists biological, chemical, geographical and geological references and covers shallow marine sediments, surf zones off...

  5. 77 FR 74341 - Establishing the Hurricane Sandy Rebuilding Task Force

    Science.gov (United States)

    2012-12-14

    ... the Hurricane Sandy Rebuilding Task Force By the authority vested in me as President by the.... Hurricane Sandy made landfall on October 29, 2012, resulting in major flooding, extensive structural damage... assist the affected region. A disaster of Hurricane Sandy's magnitude merits a comprehensive...

  6. Degradation of roxarsone in a silt loam soil and its toxicity assessment.

    Science.gov (United States)

    Liang, Tengfang; Ke, Zhengchen; Chen, Qing; Liu, Li; Chen, Guowei

    2014-10-01

    The land application of poultry or swine litter, containing large amounts of roxarsone, causes serious arsenic pollution in soil. Understanding biotransformation process of roxarsone and its potential risks favors proper disposal of roxarsone-contaminated animal litter, yet remains not achieved. We report an experimental study of biotransformation process of roxarsone in a silt loam soil under various soil moisture and temperature conditions, and the toxicity of roxarsone and its products from degradation. Results showed that soil moisture and higher temperature promoted roxarsone degradation, associating with emergent pentavalent arsenic. Analysis of fluorescein diacetate (FDA) hydrolysis activity revealed that roxarsone does not exert acute toxic on soil microbes. With the release of inorganic arsenic, FDA hydrolysis activity was inhibited gradually, as evidenced by ecotoxicological assessment using Photobacterium leiognathi. The results shade new lights on the dynamic roxarsone biotransformation processes in soil, which is important for guiding appropriate disposal of poultry or swine litter in the environment.

  7. Screening of cellulose decomposing fungi in sandy dune soil of Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    ShaoKun Wang; XueYong Zhao; XiaoAn Zuo; XinPing Liu; Hao Qu; Wei Mao; JianYing Yun

    2015-01-01

    Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi (NM3-1, NM3-2, NM3-3, and NM3-4) were screened using a CMC (carboxymethyl cellulose) carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89%by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decom-position and available nutrient input in the Horqin Sandy Land.

  8. Leaching of trifluralin, metolachlor, and metribuzin in a clay loam soil of Louisiana.

    Science.gov (United States)

    Kim, Jung-Ho; Feagley, Sam E

    2002-09-01

    Trifluralin[2,6-dinitro-N,N-dipropyl-4-(trifluormethyl)benzenamine], metolachlor[2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], and metribuzin[4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)one] were applied in field plots located on a Commerce clay loam soil near Baton Rouge, Louisiana at the rate of 1683 g/ha, 2759 g/ha and 609 g/ha, respectively. The half-lives of trifluralin, metolachlor, and metribuzin in the top 0-15 cm soil depth were found to be 54.7 days, 35.8 days and 29.8 days, respectively. The proportion of trifluralin, metolachlor, and metribuzin in the top 0-15 cm soil depth was 94.7%, 86.6%, and 75.4%, respectively of that found in the top 0-60 cm soil depth 30 days after application. Trifluralin concentrations were within a range of 0.026 ng/mL to 0.058 ng/mL in 1 m deep well water, and between 0.007 ng/mL and 0.039 ng/mL in 2 m deep well water over a 62 day period after application. Metolachlor concentrations in the 1 m and 2 m wells ranged from 3.62 ng/mL to 82.32 ng/mL and 8.44 ng/mL to 15.53 ng/mL, respectively. Whereas metribuzin concentrations in the 1 m and 2 m wells ranged from 0.70 ng/mL to 27.75 ng/mL and 1.71 ng/mL to 3.83 ng/mL, respectively. Accordingly, trifluralin was found to be strongly adsorbed on the soil and showed negligible leaching. Although metolachlor and metribuzin were also both readily adsorbed on the soil, their leaching potential was high. As a result, in the clay loam soil studied, metribuzin concentration in groundwater with shallow aquifers is likely to exceed the 10 mg/L US Environmental Protection Agency (EPA) advisory level for drinking water early in the application season, whereas trifluralin and metolachlor concentrations are expected to remain substantially lower than their respective 2 ng/mL and 175 ng/mL EPA advisory levels.

  9. Soil nitrogen dynamics and Capsicum Annuum sp. plant response to biochar amendment in silt loam soil

    Science.gov (United States)

    Horel, Agota; Gelybo, Gyorgyi; Dencso, Marton; Toth, Eszter; Farkas, Csilla; Kasa, Ilona; Pokovai, Klara

    2017-04-01

    The present study investigated the growth of Capsicum Annuum sp. (pepper) in small-scale experiment to observe changes in plant growth and health as reflected by leaf area, plant height, yield, root density, and nitrogen usage. Based on field conditions, part of the study aimed to examine the photosynthetic and photochemical responses of plants to treatments resulting from different plant growth rates. During the 12.5 week long study, four treatments were investigated with biochar amount of 0, 0.5%, 2.5%, and 5.0% (by weight) added to silt loam soil. The plants were placed under natural environmental conditions, such that photosynthetic activities from photosynthetically active radiation (PAR) and the plants photochemical reflectance index (PRI) could be continuously measured after exposure to sunlight. In this study we found that benefits from biochar addition to silt loam soil most distinguishable occurred in the BC2.5 treatments, where the highest plant yield, highest root density, and highest leaf areas were observed compared to other treatments. Furthermore, data showed that too low (0.5%) or too high (5.0%) biochar addition to the soil had diminishing effects on Capsicum Annuum sp. growth and yield over time. At the end of the 12th week, BC2.5 had 22.2%, while BC0.5 and BC5.0 showed 17.4% and 15.7% increase in yield dry weight respectively compared to controls. The collected data also showed that the PRI values of plants growing on biochar treated soils were generally lower compared to control treatments, which could relate to leaf nitrogen levels. Total nitrogen amount showed marginal changes over time in all treatments. The total nitrogen concentration showed 28.6% and 17.7% increase after the 6th week of the experiment for BC2.5 and BC5.0, respectively, while inorganic nutrients of NO3-N and NH4+-N showed a continuous decrease during the course of the study, with a substantial drop during the first few weeks. The present study provides evidence for impact

  10. Effects of deposit-feeding macrofauna on benthic bacteria, viruses, and protozoa in a silty freshwater sediment.

    Science.gov (United States)

    Wieltschnig, Claudia; Fischer, Ulrike R; Velimirov, Branko; Kirschner, Alexander K T

    2008-07-01

    In microcosm experiments, we simultaneously tested the effects of increased numbers of deposit-feeding macrofauna (chironomids, oligochaetes and cladocerans) on the standing stock, activities and interactions of heterotrophic bacteria, viruses, and bacterivorous protozoa (heterotrophic nanoflagellates and ciliates) in the aerobic layer of a silty littoral freshwater sediment. On average, bacterial secondary production was stimulated between 11 and 29% by all macrofaunal groups compared to control experiments without macrofauna addition. Bacterial standing stock increased significantly by 8 and 13% in case of chironomids and cladocerans, respectively. Oligochaetes and chironomids produced significant negative effects on viral abundance while the results with cladocerans were inconsistent. The addition of oligochaetes and chironomids resulted in a significant decrease by on average 68 and 32% of viral decay rates, respectively, used as a measure of viral production. The calculated contribution of virus-induced lysis to benthic bacterial mortality was low, with 2.8 to 11.8% of bacterial secondary production, and decreased by 39 to 81% after the addition of macrofauna compared to the control. The abundances of heterotrophic nanoflagellates were significantly reduced by 20% by all tested macrofauna groups, while ciliates showed inconsistent results. The importance of heterotrophic nanoflagellate grazing on benthic bacteria was very low (virus-induced cell lysis and protozoan grazing.

  11. Threats to sandy beach ecosystems: A review

    Science.gov (United States)

    Defeo, Omar; McLachlan, Anton; Schoeman, David S.; Schlacher, Thomas A.; Dugan, Jenifer; Jones, Alan; Lastra, Mariano; Scapini, Felicita

    2009-01-01

    We provide a brief synopsis of the unique physical and ecological attributes of sandy beach ecosystems and review the main anthropogenic pressures acting on the world's single largest type of open shoreline. Threats to beaches arise from a range of stressors which span a spectrum of impact scales from localised effects (e.g. trampling) to a truly global reach (e.g. sea-level rise). These pressures act at multiple temporal and spatial scales, translating into ecological impacts that are manifested across several dimensions in time and space so that today almost every beach on every coastline is threatened by human activities. Press disturbances (whatever the impact source involved) are becoming increasingly common, operating on time scales of years to decades. However, long-term data sets that describe either the natural dynamics of beach systems or the human impacts on beaches are scarce and fragmentary. A top priority is to implement long-term field experiments and monitoring programmes that quantify the dynamics of key ecological attributes on sandy beaches. Because of the inertia associated with global climate change and human population growth, no realistic management scenario will alleviate these threats in the short term. The immediate priority is to avoid further development of coastal areas likely to be directly impacted by retreating shorelines. There is also scope for improvement in experimental design to better distinguish natural variability from anthropogenic impacts. Sea-level rise and other effects of global warming are expected to intensify other anthropogenic pressures, and could cause unprecedented ecological impacts. The definition of the relevant scales of analysis, which will vary according to the magnitude of the impact and the organisational level under analysis, and the recognition of a physical-biological coupling at different scales, should be included in approaches to quantify impacts. Zoning strategies and marine reserves, which have not

  12. [Effects of short-term fencing on organic carbon fractions and physical stability of sandy sierozem in desert steppe of Northwest China].

    Science.gov (United States)

    Yang, Xin-Guo; Song, Nai-Ping; Li, Xue-Bin; Liu, Bing-Ru

    2012-12-01

    In order to explore the change patterns of organic carbon fractions and physical stability of sandy sierozem in desert steppe at the early stage of fencing, 0-40 cm soil samples were collected from a 5-year fenced desert steppe (inside the fence) and a free grazing steppe (outside the fence) in Yanchi County of Ningxia, Northwest China, with the soil organic carbon, labile organic carbon, and particulate organic carbon contents and soil particle composition analyzed. No significant differences were observed in the soil organic carbon content and soil particle composition inside and outside the fence. The average soil organic carbon inside and outside the fences was 3.25 g x kg(-1), the percentages of sand, silt, and clay were averagely 72%, 16%, and 12%, respectively, and the soil physical stability index was 1.30% -1.31%. The soil active organic carbon showed a significant change in 10-20 cm layer. The soil labile organic carbon content was 0.80 g x kg(-1) inside the fence, which was significantly higher than that outside the fence (0.62 g x kg(-1)). The percentage of soil particulate organic carbon was 50.9% inside the fence, which was also significantly higher than that outside the fence (31.7%). The soil texture inside the fence changed from sandy to loam, and the soil labile organic carbon content increased gradually; while the soil texture outside the fence was sandy, and its vertical change was relatively smooth. The organic carbon of sandy si- erozem in the desert steppe under the conditions of short-term fencing was still in a balance between consumption and accumulation, the soil texture was relatively stable, and the soil physical stability changed little. It was suggested that the soil active organic carbon content and its relative percentage in 10-20 cm layer could be used as the indicators of early soil quality change of desert steppe.

  13. Evaluating the relative air permeability of porous media from their water retention curves

    Science.gov (United States)

    Assouline, S.; Tuli, A.; Hopmans, J. W.

    2016-05-01

    Accurate modeling of water and air flow in porous media requires the definition of the relevant hydraulic properties, namely, the water retention curve (WRC) and the relative hydraulic conductivity function (RHC), as well as the definition of the relative air permeability function (RAP). Capitalizing on the approach developed previously to represent the RHC, a new model allowing the prediction of RAP based on information resulting from the WRC is proposed. The power value ηa in the model is a decreasing exponential function of the coefficient of variation, ɛ, characterizing the pore size distribution of the porous medium, and derived from its WRC. The model was calibrated using data from 22 disturbed and undisturbed soil samples and was validated using data from eight soil types ranging from quartz sand to silty clay loam. The proposed model provided accurate prediction of the soil RAP and performed in some cases (sandy loam and silty clay loam soils) better than available alternative models.

  14. Hurricane Sandy science plan: coastal impact assessments

    Science.gov (United States)

    Stronko, Jakob M.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

  15. Challenges of conservation agriculture practices on silty soils. Effects on soil pore and gas transport characteristics in North-eastern Italy

    DEFF Research Database (Denmark)

    Piccoli, Ilaria; Schjønning, Per; Lamandé, Mathieu

    2017-01-01

    of this study was to evaluate the effect of CA practices on gas transport characteristics in the silty soils of the Veneto Region (North-Eastern Italy). In 2010, a field experiment comparing CA practices (no-tillage, cover crop and residues retention) to conventional intensive tillage (IT) system...... was established in four farms located in the Veneto low plain. In fall 2015, 144 undisturbed 100 cm3 soil cores where collected at two different layers (3–6.5 cm and 20–23.5 cm) and analysed for air-filled porosity, air permeability, gas diffusivity and soil structure indices derived. Gas transport measurements...... highlighted low transmission properties of the silty soils independently from agronomic management. Both air permeability and relative gas diffusivity showed poor aerated conditions being generally

  16. 78 FR 32296 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

    Science.gov (United States)

    2013-05-29

    ... Response to Hurricane Sandy: Response, Recovery & Resiliency AGENCY: Federal Transit Administration (FTA... recipients most severely affected by Hurricane Sandy: the Metropolitan Transportation Authority, New Jersey... Federal Register notice, bringing the total amount of Hurricane Sandy Emergency Relief funds allocated...

  17. Organic matter dynamics in coarse sandy calcareous soils

    NARCIS (Netherlands)

    Pronk, A.A.; Reuler, van H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overest

  18. Freeze-Thaw Cycles Effects on Soil Compaction in a Clay Loam

    Science.gov (United States)

    Jabro, J.; Evans, R.; Iversen, W.

    2012-04-01

    Inappropriate soil management practices and heavier farm machinery and equipment have led to an increase in soil compaction in the last two decades prompting increased global concern regarding the impact of soil compaction on crop production and soil quality in modern mechanized agriculture. A 3-yr comprehensive study was established to evaluate the dynamic of freeze-thaw cycles on soil compaction in a clay loam soil. Plots of frozen soils were compared with plots where soils were prevented from freezing with electrically heated blankets commonly used on concrete. Results showed that frequent freeze-thaw cycles over the winter alleviated a majority of soil compaction at the 0 - 20 cm depth. Soil penetration resistance in compacted soils was reduced by 73 and 68% over the winter at the 0 - 10 and 10 - 20 cm depths, respectively, due to dynamic effects of freeze-thaw cycles on soil structure and particles configuration. In unfrozen compacted soils, the penetration resistance was also reduced by 50 and 60% over winter at the 0 - 10 and 10 - 20 cm depths, respectively, due to the biology of soil, microbial activity, and disruptive effects of shrink-swell cycles. These results have demonstrated of how repeated freeze-thaw cycles can alleviate soil compaction, alter soil physical quality and create optimal soil conditions required for profitable growth of agricultural crops. The results from this study will save growers considerable time, money and energy currently required to alleviate soil compaction using other methods such as sub-soiling and deep tillage. We believe that Mother Nature provides ways to reverse soil compaction and improve soil structure and aggregation through the dynamic of freeze-thaw cycles that soils in Montana and other parts of the country go through each year. We concluded that the Mother Nature is the most effective and cheapest way to alleviate soil compaction.

  19. Field wind tunnel testing of two silt loam soils on the North American Central High Plains

    Science.gov (United States)

    Scott Van Pelt, R.; Baddock, Matthew C.; Zobeck, Ted M.; Schlegel, Alan J.; Vigil, Merle F.; Acosta-Martinez, Veronica

    2013-09-01

    Wind erosion is a soil degrading process that threatens agricultural sustainability and environmental quality globally. Protecting the soil surface with cover crops and plant residues, practices common in no-till and reduced tillage cropping systems, are highly effective methods for shielding the soil surface from the erosive forces of wind and have been credited with beneficial increases of chemical and physical soil properties including soil organic matter, water holding capacity, and wet aggregate stability. Recently, advances in biofuel technology have made crop residues valuable feed stocks for ethanol production. Relatively little is known about cropping systems effects on intrinsic soil erodibility, the ability of the soil without a protective cover to resist the erosive force of wind. We tested the bare, uniformly disturbed, surface of long-term tillage and crop rotation research plots containing silt loam soils in western Kansas and eastern Colorado with a portable field wind tunnel. Total Suspended Particulate (TSP) were measured using glass fiber filters and respirable dust, PM10 and PM2.5, were measured using optical particle counters sampling the flow to the filters. The results were highly variable and TSP emission rates varied from less than 0.5 mg m-2 s-1 to greater than 16.1 mg m-2 s-1 but all the results indicated that cropping system history had no effect on intrinsic erodibility or dust emissions from the soil surfaces. We conclude that prior best management practices will not protect the soil from the erosive forces of wind if the protective mantle of crop residues is removed.

  20. Environmental Assessment for the Construction of a Community Activities Center, Malmstrom Air Force Base, Montana

    Science.gov (United States)

    2008-12-18

    and consist primarily of Lawther silty clay (associated with the Pleistocene till) and Dooley sandy loam (associated with the Holocene eolian sand...about 1500 to 300 years ago (about A.D. 1700) the variety of projectile points increases and pottery are more evident. Bison were still an important...flow-way. Some of the groundwater that was once flowed naturally through clay soils now flows more freely along these man-made corridors, some of it

  1. Environmental Assessment for the Construction of a Community Activities Center Malmstron Air Force Base, Montana

    Science.gov (United States)

    2008-12-01

    of Lawther silty clay (associated with the Pleistocene till) and Dooley sandy loam (associated with the Holocene eolian sand) (USAF, 2001). Other...variety of projectile points increases and pottery are more evident. Bison were still an important component on the economy. Stone circles are a...groundwater that was once flowed naturally through clay soils now flows more freely along these man-made corridors, some of it towards storm water

  2. Rediscovering community--reflections after Hurricane Sandy.

    Science.gov (United States)

    See, Sharon

    2013-01-01

    Hoboken, New Jersey, is a town of 50,000 residents located across the Hudson River from New York City. Most of Hoboken's infrastructure was compromised during Hurricane Sandy as a result of flooding and power outages that rendered many businesses inoperable, including all of the pharmacies in town. Despite a focus on emergency preparedness since Hurricane Katrina and 9/11, there were no contingencies in place to facilitate and assess the medication needs of the community in the event of a natural disaster. This essay describes how the author rediscovered the meaning of community, and through working with colleagues in other health care disciplines and non-health care volunteers, provided care to patients in suboptimal circumstances.

  3. Hurricane Sandy science plan: New York

    Science.gov (United States)

    Ransom, Clarice N.

    2013-01-01

    Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. More than one-half of the U.S. population lives within 50 miles of a coast, and this number is increasing. The U.S. Geological Survey (USGS) is one of the largest providers of geologic and hydrologic information in the world. Federal, State, and local partners depend on the USGS science to know how to prepare for hurricane hazards and reduce losses from future hurricanes. The USGS works closely with other bureaus within the Department of the Interior, the Federal Emergency Management Agency, the National Oceanic Atmospheric Administration, the U.S. Army Corps of Engineers, the Environmental Protection Agency, and many State and local agencies to identify their information needs before, during, and after hurricanes.

  4. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning;

    1991-01-01

    Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate...... processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content...... of total dissolved ions in the NO3- free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrite and ammonia are absent or found at very low concentrations. Possible electron donors...

  5. Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches

    Science.gov (United States)

    Felix, Gabriela; Marenzi, Rosemeri C.; Polette, Marcos; Netto, Sérgio A.

    2016-10-01

    Sandy beaches are central economic assets, attracting more recreational users than other coastal ecosystems. However, urbanization and landscape modification can compromise both the functional integrity and the attractiveness of beach ecosystems. Our study aimed at investigating the relationship between sandy beach artificialization and the landscape perception by the users, and between sandy beach visual attractiveness and biodiversity. We conducted visual and biodiversity assessments of urbanized and semiurbanized sandy beaches in Brazil and Uruguay. We specifically examined meiofauna as an indicator of biodiversity. We hypothesized that urbanization of sandy beaches results in a higher number of landscape detractors that negatively affect user evaluation, and that lower-rated beach units support lower levels of biodiversity. We found that urbanized beach units were rated lower than semiurbanized units, indicating that visual quality was sensitive to human interventions. Our expectations regarding the relationship between landscape perception and biodiversity were only partially met; only few structural and functional descriptors of meiofauna assemblages differed among classes of visual quality. However, lower-rated beach units exhibited signs of lower environmental quality, indicated by higher oligochaete densities and significant differences in meiofauna structure. We conclude that managing sandy beaches needs to advance beyond assessment of aesthetic parameters to also include the structure and function of beach ecosystems. Use of such supporting tools for managing sandy beaches is particularly important in view of sea level rise and increasing coastal development.

  6. Responses of submarine groundwater to silty-sand coast reclamation: A case study in south of Laizhou Bay, China

    Science.gov (United States)

    Liu, Sen; Gao, Maosheng; Tang, Zhonghua; Hou, Guohua; Guo, Fei

    2016-11-01

    Coastal reclamation can result in considerable changes in the quality and quantity of submarine groundwater at the land/sea interface. In this study, submarine groundwater monitoring wells and water samples were designed and implemented to get data of groundwater level, electrical conductivity, temperature, and hydrochemistry data to examine the responses of silty-sand submarine groundwater in different sedimentary strata to reclamation in south of Laizhou Bay. The submarine groundwater is mainly saline water and its salinity in the deep aquifer is higher than that of seawater and close to brine. It was formed in the Late Pleistocene and Holocene. Drilling core data indicates that there is a stratigraphic boundary at a depth of 18.58 m, with Holocene strata above, and Late Pleistocene strata below, this level. Continuous electrical conductivity data indicates that the submarine groundwater properties are stratigraphically distributed in this study area. And there is an interface at a depth of 38 m. Above the 38 m depth, the water quantity of submarine ground-saline water is freshening. The major ions showed a tendency to change continually above 25 m, but the tended to stabilize below 25 m depth. Freshwater is the major recharge source in the upper section of the Holocene strata, between the surface and 8.00 m depth, and the hydrochemical type has changed from Clsbnd Na to Cl·HCO3sbnd Na. In the lower section of Holocene strata (8.00-23.00 m) and upper section of late Late Pleistocene strata (23.00-38.00 m), groundwater is influenced by seawater and groundwater of upper aquifer. The freshwater, seawater, and groundwater recharge in the upper aquifer has no influence on the groundwater in the section below the late Late Pleistocene (between 38.00 and 49.15 m) and the early Late Pleistocene strata (between 49.15 and 75.00 m). The filling layer, added in the coastal reclamation project, is comprised of clayey silt and fine sand, and its high porosity means that it is

  7. Runoff of trifluralin, metolachlor, and metribuzin from a clay loam soil of Louisiana.

    Science.gov (United States)

    Kim, Jung-Ho; Feagley, Sam E

    2002-09-01

    Trifluralin[2,6-dinitro-N,N-dipropyl-4-(trifluormethyl)benzenamine], metolachlor[2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] and metribuzin[4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)one] were applied as pre-emergent herbicides to soybean plots in Louisiana (LA) at the rate of 1683 g/ha, 2759 g/ha and 609 g/ha, respectively. The concentrations of trifluralin in the runoff water ranged between 0.09 ng/mL and 0.02 ng/mL, which is lower than the 2 ng/mL US Environmental Protection Agency (EPA) advisory level for trifuralin in drinking water. Metolachlor concentrations in the runoff water ranged from 9.0 ng/mL to 221.5 ng/mL, which is both lower and higher than the 175 ng/mL EPA advisory level for metolachlor. Similarly, metribuzin concentrations in the runoff water ranged between 1.5 ng/mL and 56.2 ng/mL, which is also lower and higher than the 10 ng/mL EPA advisory level for metribuzin. Accordingly, from the field plots located on a Commerce clay loam soil in LA, although the concentration of trifluralin in runoff water were substantially lower than the EPA advisory level, metolachlor and metribuzin concentrations are likely to exceed the EPA advisory levels early on in the application season with a subsequent rapid decrease to safe levels. The total loss of trifluralin in runoff water was 0.005% of the applied amount over an 89 day period after application. The total loss of metolachlor and metribuzin in the runoff water was 4.67% and 5.36% of the applied amount, respectively, over a 22 day period after application. As such, there was almost no movement of trifluralin in the runoff water, whereas metolachlor and metribuzin were much more easily moved.

  8. Nitrogen Mineralization of a Loam Soil Supplemented with Organic–Inorganic Amendments under Laboratory Incubation

    Science.gov (United States)

    Abbasi, M. Kaleem; Khaliq, Abdul

    2016-01-01

    The quantification of nitrogen (N) supplying capacity of organic amendments applied to a soil is of immense importance to examine synchronization, N release capacity, and fertilizer values of these added materials. The aims of the present study was to determine the potential N mineralization and subsequent nitrification of separate and combined use of poultry manure (PM), wheat straw residues (WSR), and urea N (UN) applied to a loam soil incubated periodically over 140 days period. In addition, changes in total soil N and carbon contents were also monitored during the study. Treatments included: PM100, WSR100, PM50 + WSR50, UN100, UN50 + PM50, UN50 + WSR50, UN50 + PM25 + WSR25, and a control (unfertilized). All the amendments were applied on an N-equivalent basis at the rate of 200 mg N kg-1. Results indicated that a substantial quantity of N had been released from the added amendments into the soil mineral pool and the net cumulative N mineralized varied between 39 and 147 mg N kg-1, lowest in the WSR and highest in the UN50 + PM50. Significant differences were observed among the amendments and the net mineral N derived from a separate and combined use of PM was greater than the other treatments. The net cumulative N nitrified (NCNN) varied between 16 and 126 mg kg-1, highest in UN50 + PM50 treatment. On average, percentage conversion of added N into available N by different amendments varied between 21 and 80%, while conversion of applied N into NO3-–N ranged between 9 and 65%, and the treatment UN50 + PM50 displayed the highest N recovery. Urea N when applied alone showed disappearance of 37% N (N unaccounted for) at the end while application of PM and WSR with UN reduced N disappearance and increased N retention in the mineral pool for a longer period. Organic amendments alone or in combination with UN improved organic matter buildup and increased soil N concentration. These results demonstrate the existence of substantial amounts of N reserves present in PM

  9. Nitrogen mineralization of a loam soil supplemented with organic-inorganic amendments under laboratory incubation

    Directory of Open Access Journals (Sweden)

    M. Kaleem ABBASI

    2016-07-01

    Full Text Available The quantification of nitrogen (N supplying capacity of organic amendments applied to a soil is of immense importance to examine synchronization, N release capacity, and fertilizer values of these added materials. The aim of the present study was to determine the potential mineralization of separate and combined use of poultry manure (PM, wheat (Triticum aestivum L. straw residues (WSR, and urea N (UN applied to a loam soil and incubated periodically over 140 days period. Treatments included PM100, WSR100, PM50 + WSR50, UN100, UN50 + PM50, UN50 + WSR50, UN50 + PM25 + WSR25, and a control (unfertilized. Added amendments were applied on an N-equivalent basis at the rate of 200 mg N kg−1. Nitrogen supplying capacity of added materials was determined by measuring changes in total mineral N (ammonium-nitrogen and nitrate-nitrogen [NH4+–N + NO3––N] and accumulation of NO3––N over different incubation periods. Changes in soil organic matter content and total N concentration were also monitored during the study. Results indicated that added amendments released substantial N into the mineral N pool (net cumulative N mineralized [NCNM] ranged between 39 and 147 mg N kg−1, lowest in the WSR and highest in the UN50+PM50. Significant differences were observed among the amendments and the net inorganic N derived from a separate and combined use of PM was greater than the other treatments. Total inorganic N derived from PM increased from 2.3 mg kg−1 at d 1, to a maximum of 102 to 105 mg kg−1 at 63, 84 and 105 d after PM application. The values were further increase from 31.5 mg kg−1 at d 0 to a maximum of 165 mg kg−1 at d 49 in UN50 + PM50 treatment. The net cumulative N nitrified (NCNN varied between 16 and 126 mg kg−1, highest in UN50 + PM50 treatment. Soil amended with WSR100 showed negative values both for mineralization and nitrification until day 84, displaying net immobilization. On average, percentage conversion of added N into

  10. Nitrogen Mineralization of a Loam Soil Supplemented with Organic-Inorganic Amendments under Laboratory Incubation.

    Science.gov (United States)

    Abbasi, M Kaleem; Khaliq, Abdul

    2016-01-01

    The quantification of nitrogen (N) supplying capacity of organic amendments applied to a soil is of immense importance to examine synchronization, N release capacity, and fertilizer values of these added materials. The aims of the present study was to determine the potential N mineralization and subsequent nitrification of separate and combined use of poultry manure (PM), wheat straw residues (WSR), and urea N (UN) applied to a loam soil incubated periodically over 140 days period. In addition, changes in total soil N and carbon contents were also monitored during the study. Treatments included: PM100, WSR100, PM50 + WSR50, UN100, UN50 + PM50, UN50 + WSR50, UN50 + PM25 + WSR25, and a control (unfertilized). All the amendments were applied on an N-equivalent basis at the rate of 200 mg N kg(-1). Results indicated that a substantial quantity of N had been released from the added amendments into the soil mineral pool and the net cumulative N mineralized varied between 39 and 147 mg N kg(-1), lowest in the WSR and highest in the UN50 + PM50. Significant differences were observed among the amendments and the net mineral N derived from a separate and combined use of PM was greater than the other treatments. The net cumulative N nitrified (NCNN) varied between 16 and 126 mg kg(-1), highest in UN50 + PM50 treatment. On average, percentage conversion of added N into available N by different amendments varied between 21 and 80%, while conversion of applied N into NO3 (-)-N ranged between 9 and 65%, and the treatment UN50 + PM50 displayed the highest N recovery. Urea N when applied alone showed disappearance of 37% N (N unaccounted for) at the end while application of PM and WSR with UN reduced N disappearance and increased N retention in the mineral pool for a longer period. Organic amendments alone or in combination with UN improved organic matter buildup and increased soil N concentration. These results demonstrate the existence of substantial amounts of N reserves present

  11. Evaluation of the ecotoxicological impact of the organochlorine chlordecone on soil microbial community structure, abundance, and function.

    Science.gov (United States)

    Merlin, Chloé; Devers, Marion; Béguet, Jérémie; Boggio, Baptiste; Rouard, Nadine; Martin-Laurent, Fabrice

    2016-03-01

    The insecticide chlordecone applied for decades in banana plantations currently contaminates 20,000 ha of arable land in the French West Indies. Although the impact of various pesticides on soil microorganisms has been studied, chlordecone toxicity to the soil microbial community has never been assessed. We investigated in two different soils (sandy loam and silty loam) exposed to different concentrations of CLD (D0, control; D1 and D10, 1 and 10 times the agronomical dose) over different periods of time (3, 7, and 32 days): (i) the fate of chlordecone by measuring (14)C-chlordecone mass balance and (ii) the impact of chlordecone on microbial community structure, abundance, and function, using standardized methods (-A-RISA, taxon-specific quantitative PCR (qPCR), and (14)C-compounds mineralizing activity). Mineralization of (14)C-chlordecone was inferior below 1 % of initial (14)C-activity. Less than 2 % of (14)C-activity was retrieved from the water-soluble fraction, while most of it remained in the organic-solvent-extractable fraction (75 % of initial (14)C-activity). Only 23 % of the remaining (14)C-activity was measured in nonextractable fraction. The fate of chlordecone significantly differed between the two soils. The soluble and nonextractable fractions were significantly higher in sandy loam soil than in silty loam soil. All the measured microbiological parameters allowed discriminating statistically the two soils and showed a variation over time. The genetic structure of the bacterial community remained insensitive to chlordecone exposure in silty loam soil. In response to chlordecone exposure, the abundance of Gram-negative bacterial groups (β-, γ-Proteobacteria, Planctomycetes, and Bacteroidetes) was significantly modified only in sandy loam soil. The mineralization of (14)C-sodium acetate and (14)C-2,4-D was insensitive to chlordecone exposure in silty loam soil. However, mineralization of (14)C-sodium acetate was significantly reduced in soil

  12. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

    Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik

    2009-01-01

    Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits...... in south-eastern Sweden covered by xeric sand calcareous grasslands (EU habitat directive 6120). Methods: Soil and vegetation were investigated in most of the xeric sand calcareous grasslands in the Scania region (136 sample plots distributed over four or five major areas and about 25 different sites...

  13. Evaluation Of Onion Production On Sandy Soils By Use Of Reduced Tillage And Controlled Traffic Farming With Wide Span Tractors

    Directory of Open Access Journals (Sweden)

    Pedersen Hans Henrik

    2015-09-01

    Full Text Available Growing of vegetables is often characterised by intensive field traffic and use of heavy machines. By implementing controlled traffic farming (CTF, compaction of the growth zone can be avoided. An experiment was established in an onion field on a coarse sandy loam. Treatments were applied in the field that for five years had been managed by seasonal CTF (SCTF, where harvest is performed by random traffic due to lack of suitable harvest machines. The main treatment was compaction with a fully loaded potato harvester. The split treatment in the crossed split plot design was mechanical loosening. Bulk density, macroporosity, penetration resistance, water retention characteristics and yield were measured. Mechanical loosening caused improvements in the physical soil measurements and more roots were found in the upper soil layers. The highest yield was however found in the CTF simulation plots (19% higher than in the SCTF simulated plots. Using wide span tractors as a harvest platform will enable CTF in vegetable production. Avoidance of compaction will enable reduced tillage intensity and productivity can be improved both through higher yield of the area that is cropped and by a larger percentage of fields can be cropped area as less area will be needed for tracks.

  14. Two years of gaseous emissions from contrasting soils amended with organic and synthetic nitrogen fertilizers.

    Science.gov (United States)

    Pelster, D. E.; Chantigny, M. H.; Rochette, P.; Angers, D. A.; Rieux, C.; Vanasse, A.

    2012-04-01

    Animal manures are often used as a source of nitrogen (N) for agriculture; however impacts of amendment type on N2O production may vary. In this study, N2O emissions from two soil types with contrasting texture and carbon (C) content (a silty clay mixed frigid dystric eutrudept and a sandy loam mixed frigid typic dystrudept) were measured for two years under a cool, humid climate. Treatments consisted of a no N control (CTL), calcium ammonium nitrate (CAN), poultry manure (PM), liquid cattle manure (LCM), or liquid swine manure (LSM). The N sources were surface applied and immediately incorporated at 90 kg N ha-1 before seeding of spring wheat (Triticum aestivum L.). Leaching losses of N were also measured using zero-tension lysimeters located at approximately 0.35 m depth. Cumulative growing season N2O-N emissions from the silty clay ranged from 2.2 to 8.3 kg ha-1 yr-1 and were slightly lower in CTL plots than in the fertilized plots (P = 0.067). The mean N2O emission factors ranged from 2.0 to 4.4% of added N with no difference among treatments. Emissions of N2O from the sandy loam soil ranged from 0.3 to 2.2 kg N2O-N ha-1 yr-1, with greatest emissions following PM application (P < 0.001). The N2O emission factor from sandy loam plots amended with PM was 1.7%, more than double that of the other treatments (0.3 to 0.9%), likely because of the high C content of the PM. On the silty clay the yield-based N2O emissions (g N2O-N kg-1 grain yield N) were similar between treatments; while on the sandy loam, they were greatest when amended with PM. Annual N leaching losses averaged 28.7 kg ha-1 for the silty clay and 19.6 kg ha-1 for the sandy loam and were similar for all amendment types suggesting that off-site N2O emissions will also be similar amongst treatments. Preliminary data indicate that overwinter N2O emissions from sandy loam plots were consistently greater when amended with pig slurry compared with unamended soils, and that these overwinter losses may exceed

  15. On the Impact Angle of Hurricane Sandy's New Jersey Landfall

    Science.gov (United States)

    Hall, Timothy M.; Sobel, Adam H.

    2013-01-01

    Hurricane Sandy's track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record, one of the factors contributing to recordsetting peak-water levels in parts of New Jersey and New York. To estimate the occurrence rate of Sandy-like tracks, we use a stochastic model built on historical hurricane data from the entire North Atlantic to generate a large sample of synthetic hurricanes. From this synthetic set we calculate that under long-term average climate conditions, a hurricane of Sandy's intensity or greater (category 1+) makes NJ landfall at an angle at least as close to perpendicular as Sandy's at an average annual rate of 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 years (95% confidence range 435 to 1429).

  16. 2014 USGS CMGP Lidar: Post Sandy (Long Island, NY)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Long Island New York Sandy LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00296 Woolpert...

  17. Hurricane Sandy: Rapid Response Imagery of the Surrounding Regions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of Hurricane Sandy. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The images were acquired...

  18. 2008 USDA Forest Service Lidar: Sandy River Study Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data for the Sandy River study area in collaboration with the USDA Forest Service. The areas...

  19. James J. Howard Marine Sciences Laboratory @ Sandy Hook

    Data.gov (United States)

    Federal Laboratory Consortium — The James J. Howard Marine Sciences Laboratory, located on the New Jersey shore at Sandy Hook, is a state-of-the-art marine research facility shared by the National...

  20. Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Gore, P.S.; Raveendran, O.; Unnithan, R.V.

    Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches...

  1. James J. Howard Marine Sciences Laboratory @ Sandy Hook

    Data.gov (United States)

    Federal Laboratory Consortium — The James J. Howard Marine Sciences Laboratory, located on the New Jersey shore at Sandy Hook, is a state-of-the-art marine research facility shared by the National...

  2. 2014 USGS CMGP Lidar: Sandy Restoration (Delaware and Maryland)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: SANDY_Restoration_DE_MD_QL2 Area of Interest covers approximately 3.096 square miles. Lot #5 contains the full project area Dataset Description:...

  3. Short Communication Energy and ash contents of sandy beach ...

    African Journals Online (AJOL)

    macrofauna found on three exposed sandy beaches on the west coast ... that they often form the predominant shore type (Bally,. McQuaid ... their sediments are given in Table I. Animals ..... The biochemical composition of the tropical intertida1 ...

  4. Testing Some Pedo-Transfer Functions (PTFs in Apulia Region. Evaluation on the Basis of Soil Particle Size Distribution and Organic Matter Content for Estimating Field Capacity and Wilting Point

    Directory of Open Access Journals (Sweden)

    Floriano Buccigrossi

    2010-10-01

    Full Text Available The knowledge of soil water retention vs. soil water matric potential is applied to study irrigation and drainage scheduling, soil water storage capacity (plant available water, solute movement, plant growth and water stress. To measure field capacity and wilting point is expensive, laborious and is time consuming, so, frequently, matemathic models, called pedo-transfer functions (PTFs are utilized to estimate field capacity and wilting point through physical-chemical soil characteristics. Six PTFs have been evaluated (Gupta and Larson, 1979; Rawls et al., 1982; De Jong et al., 1983; Rawls and Brakensiek, 1985; Saxton et al., 1986; Vereecken et al., 1989 by comparing measured soil moisture values with estimated ones at soil water matric potential of -33 and -1500 kPa. Soil samples were collected (361 from 185 pedons of Apulian Region (Southern Italy. Accuracy of the soil moisture predictions is quantified with Root Mean Square Deviation (RMSD between estimated and measured water retention values. In Apulia Region the tested PTFs give different results on soils grouped on the basis of textural composition and organic matter (O.M. content both at the Field Capacity (FC and Wilting Point (WP. At the FC, Gupta and Larson model has given the best performance in Clayey (C, Sandy clay loam (SaCL, Sandy loam (SaL and Silty (Si soil, in loamy and tendency silty soils with O.M. content less than 1.9% and in tendency sandy soils with O.M. content less than 1.5% and greater than 2%; the Rawls model in Silty clay (SiC and Silty loam (SiL soils, in tendency clayey soils with O.M. less than 2.3% and in loamy and tendency silty soils with O.M. greater than 1.9%; the Rawls and Brakensiek model in tendency sandy soils with O.M. content between 1.5 and 2%; the Saxton model in Silty clay loam (SiCL, Loamy sand (LSa soils and in tendency clayey soils with O.M. content greater than 2.3% and the Vereecken model in Sandy clay (SaC, Loamy (L, Clay loam (CL and Sandy (Sa

  5. Sandy inland braidplain deposition with local aeolian sedimentation in the lower and middle parts of the buntsandstein and sandy coastal braidplain deposition in the topmost zechstein in the sudetes (Lower Silesia, Poland)

    Science.gov (United States)

    Mroczkowski, Jerzy; Mader, Detlef

    The lower and middle parts of the Buntsandstein between Röt and Zechstein in the Sudetes (Lower Silesia, Poland) crop out in the marginal seams of the North Sudetic Trough and the Intra Sudetic Trough. The continental red beds originate in predominantly sandy braided river systems of an extensive inland alluvial plain in almost arid climate. The sediments are laid down in channels and floodplains of a moderately- to highly-braided, sandy to pebbly stream complex consisting of narrowly- to moderately-spaced low-sinuosity watercourses and narrow to wide overbank plains between the channels. Rapid aggradation and abandonment, quick lateral migration or high avulsion rates of the considerably mobile streams result in effective combing of the interchannel areas. Persistent high-energy overspilling of watercourse banks and invasion of bed-load-saturated flood surges into the overbank areas often lead to primary restriction or even suppression of formation of topstratum suspension fines. Secondarily, the silty-clayey and fine sandy overbank sediments which could occasionally originate in remote or sheltered lakes and ponds are frequently completely reworked by considerable lateral and vertical erosion during sidewards displacement of the rivers. As a result of both primary-depositional restriction and secondary-erosional removal of floodplain fines, the channel sediments are commonly stacked upon each other to multistorey stream sand complexes. Emergence and desiccation of parts of the alluvial plain sometimes give rise to aeolian deflation and accumulation of the winnowed sand to small dunelets and wind ripple trains. The aeolian depositional environment representing a more peripheral erg facies with sheet sand interdune milieu could not be fully ascertained due to poor outcrop conditions, but is likely to occur locally in view of comparative interpretation with other mixed dune and river sand sequences in the Mid-European Buntsandstein. Variations of fluvial style are

  6. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface, Pre-Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  7. Brazilian sandy beach macrofauna production: a review

    Directory of Open Access Journals (Sweden)

    Marcelo Petracco

    2012-12-01

    Full Text Available The state of the art of the studies on the production of Brazilian sandy beach macrofauna was analyzed on the basis of the data available in the literature. For this purpose, the representativeness of the production dataset was examined by latitudinal distribution, degree of exposure and morphodynamic state of beaches, taxonomic groups, and methods employed. A descriptive analysis was, further, made to investigate the trends in production of the more representative taxonomic groups and species of sandy beach macrofauna. A total of 69 macrofauna annual production estimates were obtained for 38 populations from 25 studies carried out between 22º56'S and 32º20'S. Production estimates were restricted to populations on beaches located on the southern and southeastern Brazilian coast. Most of the populations in the dataset inhabit exposed dissipative sandy beaches and are mainly represented by mollusks and crustaceans, with a smaller number of polychaetes. The trends in production among taxonomic groups follow a similar pattern to that observed on beaches throughout the world, with high values for bivalves and decapods. The high turnover rate (P/B ratio of the latter was due to the presence of several populations of the mole crab Emerita brasiliensis, which can attain high values of productivity, in the dataset. Most of the studies focus on the comparison of production and, especially, of P/B ratio according to life history traits in populations of the same species/taxonomic group. Despite the importance of life history-production studies, other approaches, such as the effect of man-induce disturbances on the macrofauna, should be undertaken in these threatened environments.O estado da arte dos estudos de produção da macrofauna de praias arenosas brasileiras foi analisado a partir de informações disponíveis na literatura. Para essa finalidade, a representatividade dos dados de produção foi examinada de acordo com a distribuição latitudinal

  8. Modeling the transport of shigella in silty and fine sand in shallow aquifers in Caostal area of bonny Niger delta; rivers state of Nigeria

    Directory of Open Access Journals (Sweden)

    Solomon Ndubuisi Eluozo

    2012-11-01

    Full Text Available Modeling the transport of shigella in silty and fine sand formation in shallow aquifer has been developed, the model were generated to monitor the transport of shigella in coastal area of bonny, as coastal environment  there are lots of  influence in the soil formation, the major variable were considered in the development of the theoretical model, this condition were assessed and were integrated , this variables were  considered and it  develop a system that generated the model equation since the microbes are  found to be in exponential phase ,because of high degree of porosity and permeability of the soil formation, the mathematical equation  were found to  consider  these variables to ensure it predict the rate of deposition of shigella in  silty and fine sand formation, the model developed predict the transport of shigella in the coastal area of bonny, Niger Delta area of Nigeria, the model will be one of the baseline to reduce high rate of shigella  in the study area, the study has also provide a design benchmark for practicing  engineers and scientist to ensure that thorough ground are provide by application of the these design model.  

  9. Sandy River Delta Habitat Restoration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Virginia; Dobson, Robin L.

    2002-11-01

    The Sandy River Delta is located at the confluence of the Sandy and Columbia Rivers, just east of Troutdale, Oregon. It comprises about 1,400 land acres north of Interstate 84, managed by the USDA Forest Service, and associated river banks managed by the Oregon Division of State Lands. Three islands, Gary, Flag and Catham, managed by Metro Greenspaces and the State of Oregon lie to the east, the Columbia River lies to the north and east, and the urbanized Portland metropolitan area lies to the west across the Sandy River. Sandy River Delta was historically a wooded, riparian wetland with components of ponds, sloughs, bottomland woodland, oak woodland, prairie, and low and high elevation floodplain. It has been greatly altered by past agricultural practices and the Columbia River hydropower system. Restoration of historic landscape components is a primary goal for this land. The Forest Service is currently focusing on restoration of riparian forest and wetlands. Restoration of open upland areas (meadow/prairie) would follow substantial completion of the riparian and wetland restoration. The Sandy River Delta is a former pasture infested with reed canary grass, blackberry and thistle. The limited over story is native riparian species such as cottonwood and ash. The shrub and herbaceous layers are almost entirely non-native, invasive species. Native species have a difficult time naturally regenerating in the thick, competing reed canary grass, Himalayan blackberry and thistle. A system of drainage ditches installed by past owners drains water from historic wetlands. The original channel of the Sandy River was diked in the 1930's, and the river diverted into the ''Little Sandy River''. The original Sandy River channel has subsequently filled in and largely become a slough. The FS acquired approximately 1,400 acres Sandy River Delta (SRD) in 1991 from Reynolds Aluminum (via the Trust for Public Lands). The Delta had been grazed for many years

  10. Hurricane Sandy Washover Deposits on Southern Long Beach Island, NJ

    Science.gov (United States)

    Bishop, J. M.; Richmond, B. M.; Kane, H. H.; Lunghino, B.

    2015-12-01

    Hurricane Sandy washover deposits were investigated at Forsyth National Wildlife Refuge (FNWR) on Southern Long Beach Island, New Jersey in order to map deposit thickness and characterize the sedimentary deposits. FNWR was chosen as a field area because there has been relatively little anthropogenic shoreline modification since washover deposition from Hurricane Sandy. Sediment, elevation, and geophysical data were collected during the April 2015 field campaign, approximately two and a half years after the storm. Sediment deposit data included trenches, stratigraphic descriptions, bulk sediment samples, push cores, Russian cores, and photos. Computed tomography (CT) scanning was conducted on push cores in order to acquire high resolution imaging of density, grain size, and sedimentary structure. Profiles of washover elevation were measured using Differential GPS with Real Time Kinematic processing. Ground Penetrating Radar data was collected to image the depth of the deposit and identify sedimentary structures. These data sets are compared to pre- and post -Sandy lidar surveys in order to determine post-Sandy modification in the two and a half years following the hurricane. We compare sediment thickness and sedimentary characteristics to hurricane Sandy deposits elsewhere along the U.S. eastern seaboard and to tsunami deposits.

  11. EAARL Coastal Topography - Sandy Hook 2007

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Stevens, Sara; Yates, Xan; Bonisteel, Jamie M.

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Northeast Coastal and Barrier Network, Kingston, RI; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of Gateway National Recreation Area's Sandy Hook Unit in New Jersey, acquired on May 16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL) was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then

  12. Short-term Effects of Tillage Practices on Organic Carbon in Clay Loam Soil of Northeast China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A tillage experiment, consisting of moldboard plow (MP), ridge tillage (RT), and no-tillage (NT), was performed in a randomized complete block design with four replicates to study the effect of 3-year tillage management on SOC content and its distribution in surface layer (30 cm) of a clay loam soil in northeast China. NT did not lead to significant increase of SOC in topsoil (0-5 cm) compared with MP and RT; however, the SOC content in NT soil was remarkably reduced at a depth of 5-20 cm. Accordingly, short-term (3-year) NT management tended to stratify SOC concentration, but not necessarily increase its storage in the plow layer for the soil.

  13. THE EFFECT OF MIXING WITH ORGANIC SOIL ON CHANGES IN SOME PHYSICAL PROPERTIES OF A COMPACTED CLAY LOAM SOIL

    Directory of Open Access Journals (Sweden)

    Abdullah BARAN

    1996-01-01

    Full Text Available In this research, the effect of organic soil on changes in total pore space, aeration porosity, available water content and hydraulic conductivity of a compacted clay loam were investigated. By adding organic soil at rates of 0 %, 1 %, 2 % and 4 % to soil, mixtures were compacted at compaction levels of 0 kg/cm2, 0.21 kg/cm2, 1.98 kg/cm2 and 3.95 kg/cm2 Some physical properties of compacted soil were determined. Compaction decreased total pore space, areation porosity, available water content and hydraulic conductivity, but in samples with the mixing rate of 4 %, all properties inspected were affected positively in all compaction levels, except available water content

  14. The red mantle of weathering and brownish-red loam of Miaodao Islands in Shandong Province and implication in paleoclimate

    Institute of Scientific and Technical Information of China (English)

    曹家欣; 严润娥; 王欢

    1995-01-01

    The formation,age and paleoclimatic changes of the red mantle of weathering and brownish-redloam of the Miaodao Islands are dealt with for the first time.The red mantle of weathering products formedthrough Fe-Al enrichment and desilication process under wet and hot climatic conditions.The brownish-red loam isa kind of eolian loess formed under semiarid and warm climatic conditions.They correlate,respectively,with thered clay of Pliocene and Wucheng Loess occurring in the inland of North China.They indicate that an abruptchange of climatic conditions took place during the turn of Pliocene and Pleistocene.This change may relate to theglobal climatic change.

  15. Influence of Long-term Application of Feedlot Manure Amendments on Water Repellency of a Clay Loam Soil.

    Science.gov (United States)

    Miller, Jim J; Beasley, Bruce W; Hazendonk, Paul; Drury, Craig F; Chanasyk, David S

    2017-05-01

    Long-term application of feedlot manure to cropland may increase the quantity of soil organic carbon (C) and change its quality, which may influence soil water repellency. The objective was to determine the influence of feedlot manure type (stockpiled vs. composted), bedding material (straw [ST] vs. woodchips [WD]), and application rate (13, 39, or 77 Mg ha) on repellency of a clay loam soil after 17 annual applications. The repellency was determined on all 14 treatments using the water repellency index ( index), the water drop penetration time (WDPT) method, and molarity of ethanol (MED) test. The C composition of particulate organic matter in soil of five selected treatments after 16 annual applications was also determined using C nuclear magnetic resonance-direct polarization with magic-angle spinning (NMR-DPMAS). Manure type had no significant ( > 0.05) effect on index and WDPT, and MED classification was similar. Mean index and WDPT values were significantly greater and MED classification more hydrophobic for WD than ST. Application rate had no effect on the index, but WDPT was significantly greater and MED classification more hydrophobic with increasing application rate. Strong ( > 0.7) but nonsignificant positive correlations were found between index and WDPT versus hydrophobic (alkyl + aromatic) C, lignin at 74 ppm (O-alkyl), and unspecified aromatic compounds at 144 ppm. Specific aromatic compounds also contributed more to repellency than alkyl, O-alkyl, and carbonyl compounds. Overall, all three methods consistently showed that repellency was greater for WD- than ST-amended clay loam soil, but manure type had no effect. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Did Hurricane Sandy influence the 2012 US presidential election?

    Science.gov (United States)

    Hart, Joshua

    2014-07-01

    Despite drawing on a common pool of data, observers of the 2012 presidential campaign came to different conclusions about whether, how, and to what extent "October surprise" Hurricane Sandy influenced the election. The present study used a mixed correlational and experimental design to assess the relation between, and effect of, the salience of Hurricane Sandy on attitudes and voting intentions regarding President Barack Obama and Mitt Romney in a large sample of voting-aged adults. Results suggest that immediately following positive news coverage of Obama's handling of the storm's aftermath, Sandy's salience positively influenced attitudes toward Obama, but that by election day, reminders of the hurricane became a drag instead of a boon for the President. In addition to theoretical implications, this study provides an example of how to combine methodological approaches to help answer questions about the impact of unpredictable, large-scale events as they unfold.

  17. Hurricane Sandy, Disaster Preparedness, and the Recovery Model.

    Science.gov (United States)

    Pizzi, Michael A

    2015-01-01

    Hurricane Sandy was the second largest and costliest hurricane in U.S. history to affect multiple states and communities. This article describes the lived experiences of 24 occupational therapy students who lived through Hurricane Sandy using the Recovery Model to frame the research. Occupational therapy student narratives were collected and analyzed using qualitative methods and framed by the Recovery Model. Directed content and thematic analysis was performed using the 10 components of the Recovery Model. The 10 components of the Recovery Model were experienced by or had an impact on the occupational therapy students as they coped and recovered in the aftermath of the natural disaster. This study provides insight into the lived experiences and recovery perspectives of occupational therapy students who experienced Hurricane Sandy. Further research is indicated in applying the Recovery Model to people who survive disasters. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  18. Effect of nitrogen and water availability of three soil types on yield, radiation use efficiency and evapotranspiration in field-grown quinoa

    DEFF Research Database (Denmark)

    Razzaghi, Fatemeh; Plauborg, Finn; Jacobsen, Sven-Erik

    2012-01-01

    in field lysimeters with sand, sandy loam and sandy clay loam soil. Despite application of the same amount of nitrogen (120 kg N ha−1) to all plots, there were large differences in crop nitrogen-uptake for sandy clay loam (134 kg ha−1), sandy loam (102 kg ha−1) and sand (77 kg ha−1) under full irrigation...

  19. Family Structures, Relationships, and Housing Recovery Decisions after Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Ali Nejat

    2016-04-01

    Full Text Available Understanding of the recovery phase of a disaster cycle is still in its infancy. Recent major disasters such as Hurricane Sandy have revealed the inability of existing policies and planning to promptly restore infrastructure, residential properties, and commercial activities in affected communities. In this setting, a thorough grasp of housing recovery decisions can lead to effective post-disaster planning by policyholders and public officials. The objective of this research is to integrate vignette and survey design to study how family bonds affected rebuilding/relocating decisions after Hurricane Sandy. Multinomial logistic regression was used to investigate respondents’ family structures before Sandy and explore whether their relationships with family members changed after Sandy. The study also explores the effect of the aforementioned relationship and its changes on households’ plans to either rebuild/repair their homes or relocate. These results were compared to another multinomial logistic regression which was applied to examine the impact of familial bonds on respondents’ suggestions to a vignette family concerning rebuilding and relocating after a hurricane similar to Sandy. Results indicate that respondents who lived with family members before Sandy were less likely to plan for relocating than those who lived alone. A more detailed examination shows that this effect was driven by those who improved their relationships with family members; those who did not improve their family relationships were not significantly different from those who lived alone, when it came to rebuilding/relocation planning. Those who improved their relationships with family members were also less likely to suggest that the vignette family relocate. This study supports the general hypothesis that family bonds reduce the desire to relocate, and provides empirical evidence that family mechanisms are important for the rebuilding/relocating decision

  20. Discontinuity networks in mud stones: an apparent contradiction for boom clay at Mol, opalinus clay at Mont Terri, Callovo-Oxfordian silty clay at Bure

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M. [Centre de Geologie de l' Ingenieur, 75 - Paris (France); Mazurek, M. [Bern Univ., Rock-Water Interaction, Institute of Geological Sciences (Switzerland); Vandenberghe, N. [Katholieke Universiteit (KU), Lab. voor stratigrafie Leuven (Belgium)

    2005-07-01

    The Rupelian Boom Clay at Mol, Belgium, the lower Aalenian Opalinus Clay at Mont Terri Switzerland and the Callovo-Oxfordian silty clay at Bure, France, are currently studied in the framework of deep geological radioactive waste confinement. These three mud-stones are calcareous to variable degrees. They vary from plastic clay at Mol to hard rock at Bure. All three have similar mineralogical constituents, especially with regards to the clay minerals and include mixed layers of illite and montmorillonite. Remarkably, in outcrop sections of massive clay formations and mud-stone in general, it is very common to observe a network of discontinuities resembling the jointing in hard rock. As such jointing clearly would influence underground works it is imperative to examine whether or not the three mud-rock formations under discussion have such a discontinuity network in all their mass. (authors)

  1. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Derived products of a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012...

  2. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar-extracted dune features

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Dune crest and toe positions along a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October...

  3. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Derived products of a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012 hurricane...

  4. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  5. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Digital elevation model (DEM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A DEM was produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012...

  6. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  7. STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-hua; DONG Guang-rong; LI Sen; DONG Yu-xiang

    2005-01-01

    The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region's natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

  8. Use of a size-resolved 1-D resuspension scheme to evaluate resuspended radioactive material associated with mineral dust particles from the ground surface.

    Science.gov (United States)

    Ishizuka, Masahide; Mikami, Masao; Tanaka, Taichu Y; Igarashi, Yasuhito; Kita, Kazuyuki; Yamada, Yutaka; Yoshida, Naohiro; Toyoda, Sakae; Satou, Yukihiko; Kinase, Takeshi; Ninomiya, Kazuhiko; Shinohara, Atsushi

    2017-01-01

    A size-resolved, one-dimensional resuspension scheme for soil particles from the ground surface is proposed to evaluate the concentration of radioactivity in the atmosphere due to the secondary emission of radioactive material. The particle size distributions of radioactive particles at a sampling point were measured and compared with the results evaluated by the scheme using four different soil textures: sand, loamy sand, sandy loam, and silty loam. For sandy loam and silty loam, the results were in good agreement with the size-resolved atmospheric radioactivity concentrations observed at a school ground in Tsushima District, Namie Town, Fukushima, which was heavily contaminated after the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Though various assumptions were incorporated into both the scheme and evaluation conditions, this study shows that the proposed scheme can be applied to evaluate secondary emissions caused by aeolian resuspension of radioactive materials associated with mineral dust particles from the ground surface. The results underscore the importance of taking soil texture into account when evaluating the concentrations of resuspended, size-resolved atmospheric radioactivity.

  9. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    Science.gov (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  10. Deaths associated with Hurricane Sandy - October-November 2012.

    Science.gov (United States)

    2013-05-24

    On October 29, 2012, Hurricane Sandy hit the northeastern U.S. coastline. Sandy's tropical storm winds stretched over 900 miles (1,440 km), causing storm surges and destruction over a larger area than that affected by hurricanes with more intensity but narrower paths. Based on storm surge predictions, mandatory evacuations were ordered on October 28, including for New York City's Evacuation Zone A, the coastal zone at risk for flooding from any hurricane. By October 31, the region had 6-12 inches (15-30 cm) of precipitation, 7-8 million customers without power, approximately 20,000 persons in shelters, and news reports of numerous fatalities (Robert Neurath, CDC, personal communication, 2013). To characterize deaths related to Sandy, CDC analyzed data on 117 hurricane-related deaths captured by American Red Cross (Red Cross) mortality tracking during October 28-November 30, 2012. This report describes the results of that analysis, which found drowning was the most common cause of death related to Sandy, and 45% of drowning deaths occurred in flooded homes in Evacuation Zone A. Drowning is a leading cause of hurricane death but is preventable with advance warning systems and evacuation plans. Emergency plans should ensure that persons receive and comprehend evacuation messages and have the necessary resources to comply with them.

  11. Hurricane Sandy: An Educational Bibliography of Key Research Studies

    Science.gov (United States)

    Piotrowski, Chris

    2013-01-01

    There, undoubtedly, will be a flurry of research activity in the "Superstorm" Sandy impact area on a myriad of disaster-related topics, across academic disciplines. The purpose of this study was to review the disaster research related specifically to hurricanes in the educational and social sciences that would best serve as a compendium…

  12. Patterns of species richness in sandy beaches of South America

    African Journals Online (AJOL)

    Species richness of the intertidal macroinfauna of exposed sandy beaches around South America is reviewed in relation ... The middle shore is prim

  13. Microfungi diversity isolation from sandy soil of Acapulco touristic beaches

    Science.gov (United States)

    Microscopic fungi diversity in marine sandy soil habitats is associated with key functions of beach ecosystems. There are few reports on their presence in Mexican beaches. Although standard methods to obtain the fungi from soil samples are established, the aim of this pilot study was to test the pla...

  14. 78 FR 46999 - Additional Waivers and Alternative Requirements for Hurricane Sandy Grantees in Receipt of...

    Science.gov (United States)

    2013-08-02

    ... URBAN DEVELOPMENT Additional Waivers and Alternative Requirements for Hurricane Sandy Grantees in... impacted and distressed areas declared a major disaster due to Hurricane Sandy (see 78 FR 14329, published....) (Stafford Act), due to Hurricane Sandy and other eligible events in calendar years 2011, 2012, and 2013....

  15. 77 FR 74891 - Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy

    Science.gov (United States)

    2012-12-18

    ... COMMISSION Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy December 12, 2012. I. Introduction Hurricane Sandy made landfall along the mid-Atlantic Coast on October 29... in the Vault at the time Hurricane Sandy made landfall, facilitating DTCC's ability to...

  16. 78 FR 33467 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

    Science.gov (United States)

    2013-06-04

    ... Response to Hurricane Sandy: Response, Recovery & Resiliency; Correction AGENCY: Federal Transit... by Hurricane Sandy. This amount was in addition to the initial $2 billion allocation announced in the... allocation restoration FTA Section 5324 Emergency Relief Program Allocations for Hurricane Sandy, by...

  17. 33 CFR 165.507 - Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD.

    Science.gov (United States)

    2010-07-01

    ... south (eastbound) span of the William P. Lane Jr. Memorial Bridge, from the western shore at Sandy Point..., between Sandy Point and Kent Island, MD. 165.507 Section 165.507 Navigation and Navigable Waters COAST... Guard District § 165.507 Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD. (a...

  18. Connectivity and percolation of pore networks in a cultivated silt loam soil quantified by X-ray tomography

    Science.gov (United States)

    Jarvis, Nicholas; Koestel, John; Larsbo, Mats

    2016-04-01

    The connectivity of macropore networks is thought to exert an important control on transport processes in soil. However, little progress has been made towards quantifying these effects for natural soils in the field, partly because of the experimental difficulties but also because the concept of connectivity lacks a unique mathematical definition. To investigate this question, X-ray tomography was used to measure pore volume, size distribution and connectivity at an image resolution of 65 microns for 64 samples taken in two consecutive years in the harrowed and ploughed layers of a silt loam soil a few weeks after spring cultivation. Three different connectivity metrics were evaluated and compared: one local metric, the Euler number, and two global measures, the connection probability and the probability of percolation (the fraction of the porosity which is continuous across the sample). The connection probability was found to be a good measure of the long-range connectivity (i.e. continuity) of the pore networks. In contrast, the Euler number was not a sensitive measure of global connectivity, although all samples with negative Euler numbers did percolate. We also found that the way connection is defined in the image analysis (either by 6 or 26 nearest neighbours) did not influence the calculations of percolating porosity. The results also demonstrate that harrowing has a clear homogenizing effect on the distribution of the pore space. However, a comparison with random field simulations and the evidence of small percolation thresholds shows that the macropore system developed in the recently harrowed soil was far from completely random or disordered. In some samples, more than one pore cluster percolated, while in others the percolating cluster was not the largest one. Nevertheless, the macropore networks in this cultivated silt loam soil displayed some key features predicted by percolation theory: a strong relationship was found between the percolating fraction

  19. Escoamento superficial e desagregação do solo em entressulcos em solo franco-argilo-arenoso com resíduos vegetais Interrill surface runoff and soil detachment on a sandy clay loam soil with residue cover

    Directory of Open Access Journals (Sweden)

    Elemar Antonino Cassol

    2004-07-01

    Full Text Available A presença de resíduos vegetais sobre a superfície do solo altera as características do escoamento superficial gerado pela chuva e a desagregação e transporte de sedimento resultantes do processo erosivo. O objetivo deste trabalho foi avaliar as condições hidráulicas e as relações de desagregação do solo e de resistência ao escoamento com a presença de resíduos vegetais na erosão em entressulcos. O experimento foi realizado no laboratório, com um Argissolo Vermelho distrófico típico, em parcelas com 0,10 m m-1 de declive sob chuva simulada. O solo foi coberto por resíduos vegetais de palha de soja, nas doses de 0, 0,05, 0,1, 0,2, 0,4 e 0,8 kg m-2. O aumento na cobertura do solo (CS com resíduos vegetais elevou a altura da lâmina de escoamento e a rugosidade hidráulica e reduziu a velocidade média do escoamento, provocada pelo aumento das forças viscosas promovida pela interposição física dos resíduos ao escoamento. O resultado é a redução na taxa de desagregação do solo (Di. A Di foi de 5,35x10-4 kg m-2 s-1 para solo descoberto e 1,50x10-5 kg m-2 s-1 em solo com 100% de cobertura na maior dose de palha. Os modelos de Laflen e potencial foram adequados para estimar o coeficiente de cobertura para resíduo em contato direto com a superfície do solo em função da cobertura do solo.Soil surface cover with crop residue modifies surface flow characteristics, generated by excess rainfall, and soil detachment and sediment transport resulting from the erosion process. The objective of this study was to evaluate the hydraulic conditions, detachment and flow resistance on interrill erosion on soil covered with residue. The experiment was conducted in the laboratory, on a Hapludult soil at a slope of 0.10 m m-1, under simulated rainfall and soil surface covered with soybean residue at the rates of 0, 0.05, 0.1, 0.2, 0.4, and 0.8 kg m-2. The increase in soil surface cover (SC with residue, caused an increase in water flow depth and hydraulic roughness, and a decrease in the mean flow velocity, due to an increase in the viscous forces from the physical interference of residue on runoff, thus contributing to a reduction in interrill soil detachment rate (Di. The Di was 5.35x10-4 kg m-2 s-1 for bare soil and was reduced to 1.50x10-5 kg m-2 s-1 for soil with 100% of surface cover. The Laflen's and the potential models were adequate to estimate the coefficient of soil coverage by residue in direct contact with soil as a function of the soil surface cover.

  20. Removal of a mixture of pesticides by a Streptomyces consortium: Influence of different soil systems.

    Science.gov (United States)

    Fuentes, María S; Raimondo, Enzo E; Amoroso, María J; Benimeli, Claudia S

    2017-04-01

    Although the use of organochlorine pesticides (OPs) is restricted or banned in most countries, they continue posing environmental and health concerns, so it is imperative to develop methods for removing them from the environment. This work is aimed to investigate the simultaneous removal of three OPs (lindane, chlordane and methoxychlor) from diverse types of systems by employing a native Streptomyces consortium. In liquid systems, a satisfactory microbial growth was observed accompanied by removal of lindane (40.4%), methoxychlor (99.5%) and chlordane (99.8%). In sterile soil microcosms, the consortium was able to grow without significant differences in the different textured soils (clay silty loam, sandy and loam), both contaminated or not contaminated with the OPs-mixture. The Streptomyces consortium was able to remove all the OPs in sterile soil microcosm (removal order: clay silty loam > loam > sandy). So, clay silty loam soil (CSLS) was selected for next assays. In non-sterile CSLS microcosms, chlordane removal was only about 5%, nonetheless, higher rates was observed for lindane (11%) and methoxychlor (20%). In CSLS slurries, the consortium exhibited similar growth levels, in the presence of or in the absence of the OPs-mixture. Not all pesticides were removed in the same way; the order of pesticide dissipation was: methoxychlor (26%)>lindane (12.5%)>chlordane (10%). The outlines of microbial growth and pesticides removal provide information about using actinobacteria consortium as strategies for bioremediation of OPs-mixture in diverse soil systems. Texture of soils and assay conditions (sterility, slurry formulation) were determining factors influencing the removal of each pesticide of the mixture.

  1. Discussion on natural purification abilities of sandy water-bearing media to garbage pollutants%砂性含水介质对垃圾污染质的自然净化能力探讨

    Institute of Scientific and Technical Information of China (English)

    孙振营; 席雪萍; 李强; 李俊香; 高学飞

    2013-01-01

    含水介质对垃圾污染质的自然净化能力受多项因素影响,是一个相当复杂的综合过程.本文选定生活垃圾淋滤液中对地下水有影响的主要污染物TP、COD、TN、NH3-N和细菌为试验污染组分,天津地区常见的中砂、粉砂和粉土为试验土样,通过室内模拟试验,利用表征指标—截留量和净化率,探讨砂性含水介质对垃圾污染质的自然净化能力.试验结果表明,指标值越大,含水介质对污染组分的自然净化能力越强;不同砂性含水介质对不同垃圾污染质的自然净化能力没有一致性规律.因此,在探讨含水介质对垃圾污染质的自然净化能力时,既要考虑含水介质的不同,也要分析污染质中不同污染组分含量的大小.%The natural purification abilities of sandy water-bearing media to garbage pollutants are influenced by many factors, which are a rather complicated process. Taking the main pouutants such as the TP, COD, TN, NH3 - N and bacteria as the test pollution compositions, and taking the medium sand, the silty sand and the silt in Tanjin as the test soil samples, though the laboratory simulation test, the interception and the purification the natural purification abilities of sandy water-bearing media to garbage pollutants are discussed. Basis on the calculation result, the greater the values are the higher the natural purification abilities of sandy water-bearing media to garbage pollutants; the natural purification abilities have unconformity rules for different sandy water-bearing media to different garbage pollutants. So when the natural purification abilities of sandy water-bearing media to garbage pollutants are discassed the difference of water-bearing media should be considered and the contents of pollution compositions, should also be analyzed.

  2. Analyze of waves dynamic over an intertidal mudflat of a sandy-gravely estuarine beach - Field survey and preliminary modeling approach

    Science.gov (United States)

    Morio, Olivier; Sedrati, Mouncef; Goubert, Evelyne

    2014-05-01

    As well as marine submersion or erosive phenomena, clay-silted sediment in-filling on estuarial and bay beaches are a main issue in these human-attractive areas. Coupled sandy/gravely and clay/silty intertidal areas can be observed in these particular coastal areas, depending of rivers characteristic (discharge of particle, water flow), ocean dynamics (wave exposure, current) and sediments sources. All around the world, sandy/gravely beaches are exposed to punctual or continuous input clay sediments. Vilaine estuary, Bay of Arcachon and Bay of Seine in France, Plymouth Bay in UK and also Wadden Sea in Deutschland are few examples of muddy/sandy coupled or mixed system. The beach of Bétahon (Ambon town, Brittany - France) is located on the external Vilaine estuary and is an example of this issue. This meso-macrotidal intermediate (low tide terrace) beach presents heterogeneous sediments. The upper intertidal zone is composed by sand and gravel and characterized by a steep slope. A very gentle slope characterized the lower part of the beach and is constituted by silt and clay. Clay/sand limit is characterized by a decimetric erosion cliff of mudflat along the beach. In order to understand bed variations and sediment transport of this complex heterogeneous beach, a well understanding of wave dynamic across the beach is necessary. This study focus on wave dynamics over the beach, using field observations and MIKE 21 3D wave numerical model. This paper is a preliminary approach of an upcoming global understanding of this estuarial beach behavior. Swell from deep-sea to near-shore area is modeled over a 100 km² area and real wind, deep sea wave characteristic, river water flow and tidal level are defined as open boundary conditions for the regional model. This last one is based on multiple bathymetric surveys over the last 50 years. Local model, triangular mesh gridded to 5 meters, covering Bétahon beach , is based on topographic and photographic survey of the mudflat

  3. BIOSYNTHESIS OF AgNPs WITH THREE WIDESPREAD LOAM FUNGI VIA ASPERGILLUS FUMIGATUS, FUSARIUM SPP. RHIZOPUS SPP.

    Directory of Open Access Journals (Sweden)

    P. SHIVAKUMAR SINGH

    2016-05-01

    Full Text Available Objectives: Biosynthesis of silver nanoparticles using fungi Aspergillus fumigatus, Fusarium spp. and Rhizopus spp. for the potential synthesis of metal nanoparticles. Methods: The standard techniques have been followed for the AgNPs synthesis characterizations. Spectral analysis of UV-visible spectroscopy, Transmission Electron Microscopy, X-ray diffraction studies, energy dispersive X-ray, Fourier transforms infrared spectroscopy. Results: The hurried decline of silver (Ag+ ions was monitored using a UV-visible spectrophotometer and showed the formation of silver nanoparticles within 28 minutes. Transmission electron microscopy (TEM showed that the synthesized silver nanoparticles are varied from 15-50 nm and have the varying in shapes like round, rod, uneven. Further, the XRD analysis confirms the nano-crystalline phase of the silver structure. FTIR examinations confirm the Silver particles. The present study, it reveals the increasing broth concentration increases the rate of reduction and decreases the particle size. Conclusion: The AgNPs were biologically synthesized using isolated fungal species biomass from the soil of loam. The cell filtrate of fungi was challenged with 1mm Silver nitrate, change of mixture from colorless to orange-brown indicates the synthesis of AgNPs in the reaction mixture. The isolated fungi are an important producer of Silver nanoparticles.

  4. The biogenic emission potential of nitric oxide from sandy soils

    Science.gov (United States)

    Yu, J. B.; Meixner, F. X.; Sun, Z. G.; Chen, X. B.; Mamtimin, B.

    2009-04-01

    There are about 160.9 Mha of sandy land in China, about 17.6% of total Chinese area, which mainly distributed in 35°-50° N. The western Songnen Plain, which located in the semi-arid region of Northeastern China, is one of the main sandy soil distribution regions. The changes of land use in sandy soil are accompanied by changes in biogeochemical cycles of nutrients, particularly of the air-surface exchange of trace gases like nitric oxide. Our study, based on results obtained by a laboratory incubation technique, focuses on (a) NO production and consumption in sandy soils from two types of land use as function of soil temperature and soil moisture, and (b) The biogenic emission potential of nitric oxide from sandy soils in semi-arid region. At 25˚C, average NO production (in terms of mass of N) was 0.016,and 0.013 ng kg-1s-1 in sandy soils from soybean land (SL) and man-made forest (MF), re¬spectively. NO consumption rate constant ranged from 0.26×10-6 to 7.28×10-6 m3 kg-1s-1. At 25˚C and under optimum soil moisture conditions for NO production, the NO compensation point mixing ratio was about 266 and 161 ug m-3 (465,and 281 ppb) for soils of SL and MF, respectively. Statistically sound relationships have been observed between NO fluxes and soil moisture (optimum curves). NO fluxes also increased exponentially with soil temperature at any given soil moisture. The optimum soil moisture for which maximum NO flux was observed was independent of soil temperature. The maximum of NO flux potentials for SL and MF soils (at 25°C) were 59.6 and 36.5 ng m-2s-1 at water-filled pore space (%WFPS) of 26 and 24, respectively. The NO flux potential was about 2 times larger for cropland soil than for man-made forest soils, most likely due to fertilizer application to the cropland soils.

  5. Landscape Change and Sandy Desertification Monitoring and Assessment

    Directory of Open Access Journals (Sweden)

    Eltahir M. Elhadi

    2009-01-01

    Full Text Available Problem statement: The objective of this study is to develop techniques for assessing and analyzing sand desertification in the northern part of Shaanxi Province, China. Approach: In order to reveal the process of land degradation, especially the latest situation of sandy desertification, a method integrating remote sensing, Geographic Information System (GIS and field survey was employed to build a sandy desertification dataset for analysis. Remote Sensing images included the Landsat Thematic Mapper (TM images in 1987 and Landsat Enhanced Thematic Mapper Plus (ETM+ images in 1999. Eight land-cover classes, including active sand dunes, fixed sand dunes, semi-fixed sand dunes, grass land, farm land, wet land, built up area and unused land and Normalized Difference Vegetation Index (NDVI, were identified. Results: The results showed that the active sand dunes and semi-fixed sand dunes have increased with a change rate of 128.70 and 55.65 km2 year-1, respectively, in the meantime the fixed sand dunes has decreased with a decreasing rate of 182.14 km2 year-1. During the 1987s, the area of sandy desertified land reached 12,006.11 km2 (57.17% of the total sandy area, of which severely desertified, medium desertified and slightly desertified land areas were 4,442.23, 4,253.45 and 3,310.43 km2, respectively. By the year 1999, the area of desertified land was increased to 13,782.30 km2 (65.63% of the total sandy area, of which severely desertified, medium desertified and slightly desertified land areas were 5,169.89, 4,918.15 and 3,694.26 km2, respectively increasing by 1,776.19 km2. Conclusion: Spatial change detection based on active sand dunes showed that the expansion area was much larger than the reversion in the past two decades and that several active sand belts has been formed, suggesting that sandy desertification of northern part of Shaanxi Province, China, will be a long-term task.

  6. Sandy Desertification Status and its Driving Mechanism in North Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang

    2004-01-01

    As the main body of Qinghai-Tibetan Plateau, North Tibet Plateau is one of three major sandy desertification regions in China and also a representative sandy desertification zone of Qinghai-Tibet Plateau. Accordingly, it is an important region for the study of recent sandy desertification processes and formation mechanism. From such aspects as desertified land types, areas and distributions etc., this paper analyses in detail the sandy desertification status on North Tibet Plateau,and qualitatively and quantitatively deals with the main factors that affect recent sandy desertification processes and the driving mechanism. Research results show that North Tibet Plateau is an important sandy desertification region in China characterized with large desertified land areas, diversified types,high severity, extensive distributions and serious damages. Sandy desertification occurrence and development resulted from combined effects of natural factors, anthropogenic factors, natural processes and man-made processes, of which climatic change is the main driving force.

  7. Quantifying the digital traces of Hurricane Sandy on Flickr.

    Science.gov (United States)

    Preis, Tobias; Moat, Helen Susannah; Bishop, Steven R; Treleaven, Philip; Stanley, H Eugene

    2013-11-05

    Society's increasing interactions with technology are creating extensive "digital traces" of our collective human behavior. These new data sources are fuelling the rapid development of the new field of computational social science. To investigate user attention to the Hurricane Sandy disaster in 2012, we analyze data from Flickr, a popular website for sharing personal photographs. In this case study, we find that the number of photos taken and subsequently uploaded to Flickr with titles, descriptions or tags related to Hurricane Sandy bears a striking correlation to the atmospheric pressure in the US state New Jersey during this period. Appropriate leverage of such information could be useful to policy makers and others charged with emergency crisis management.

  8. Determining the extent of groundwater interference on the performance of infiltration trenches

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen;

    2015-01-01

    depth of less than 1.5-3. m in sandy loam, 6.5-8. m in silt loam and 11-12. m in silty clay loam. A correction factor that can be applied for infiltration trench design when there is a shallow groundwater table is presented. The analyses showed that below a certain value of unsaturated depth...... the dissipation capacity of the mound/groundwater becomes the dominant process determining the infiltration capacity from infiltration trenches. In these cases it is essential to consider the local groundwater conditions in the infiltration trench design process.......Infiltration trenches are widely used in stormwater management, but their capacity decreases when installed in areas with shallow groundwater where infiltration is limited by groundwater drainage. Here the hydrological performance of single infiltration trenches in areas with shallow water tables...

  9. Quantifying the Digital Traces of Hurricane Sandy on Flickr

    OpenAIRE

    Preis, Tobias; Moat, Helen Susannah; Bishop, Steven R.; Treleaven, Philip; Stanley, H. Eugene

    2013-01-01

    Society’s increasing interactions with technology are creating extensive “digital traces” of our collective human behavior. These new data sources are fuelling the rapid development of the new field of computational social science. To investigate user attention to the Hurricane Sandy disaster in 2012, we analyze data from Flickr, a popular website for sharing personal photographs. In this case study, we find that the number of photos taken and subsequently uploaded to Flickr with titles, desc...

  10. Brazilian sandy beaches: characteristics, ecosystem services, impacts, knowledge and priorities

    Directory of Open Access Journals (Sweden)

    Antonia Cecília Zacagnini Amaral

    Full Text Available ABSTRACT Sandy beaches constitute a key ecosystem and provide socioeconomic goods and services, thereby playing an important role in the maintenance of human populations and in biodiversity conservation. Despite the ecological and social importance of these ecosytems, Brazilian sandy beaches are significantly impacted by human interference, chemical and organic pollution and tourism, as well as global climate change. These factors drive the need to better understand the environmental change and its consequences for biota. To promote the implementation of integrated studies to detect the effects of regional and global environmental change on beaches and on other benthic habitats of the Brazilian coast, Brazilian marine researchers have established The Coastal Benthic Habitats Monitoring Network (ReBentos. In order to provide input for sample planning by ReBentos, we have conducted an intensive review of the studies conducted on Brazilian beaches and summarized the current knowledge about this environment. In this paper, we present the results of this review and describe the physical, biological and socioeconomics features of Brazilian beaches. We have used these results, our personal experience and worldwide literature to identify research projects that should be prioritized in the assessment of regional and global change on Brazilian sandy beaches. We trust that this paper will provide insights for future studies and represent a significant step towards the conservation of Brazilian beaches and their biodiversity.

  11. Hurricane Sandy washover deposits on Fire Island, New York

    Science.gov (United States)

    La Selle, SeanPaul M.; Lunghino, Brent D.; Jaffe, Bruce E.; Gelfenbaum, Guy; Costa, Pedro J.M.

    2017-02-16

    Washover deposits on Fire Island, New York, from Hurricane Sandy in 2012 were investigated a year after the storm to document the sedimentary characteristics of hurricane washover features. Sediment data collected in the field includes stratigraphic descriptions and photos from trenches, bulk sediment samples, U-channels, and gouge and push cores. Samples and push cores were further analyzed in the laboratory for grain size, density variations using x-ray computed tomography (CT), and surface microtexture using a scanning electron microscope (SEM). Elevation profiles of washover features were measured using Differential Global Positioning System (DGPS) with Real Time Kinematic processing. The DGPS elevations were compared to lidar (light detection and ranging) data from pre- and post-Sandy surveys to assess the degree to which washover deposit thicknesses changed within the year following deposition. Hurricane Sandy washover deposits as much as 1 meter thick were observed in trenches. Initial results show that the upper parts of the deposits have been reworked significantly in some places by wind, but there are still areas where the deposits are almost entirely intact. Where mostly intact, the washover deposits consist of massive or weakly laminated sand near the base, overlain by more strongly laminated sands.

  12. Effect of over-consolidation and shear rate on the residual strength of soils of silty sand in the Three Gorges Reservoir.

    Science.gov (United States)

    Li, Deying; Yin, Kunlong; Glade, Thomas; Leo, Chin

    2017-07-14

    Estimation of the residual strength of the soil on the landslide sliding surface is essential for analyzing reactivated landslides. This study investigated the influence of over-consolidation ratio (OCR) and shear rate on the residual strength of SM-type (silty sand) landslide soils in the Three Gorge Reservoir using ring shear tests under drained conditions. A series of ring shear tests were conducted to measure the drained residual strength under over-consolidation ratios of 1-12 and shear rates of 0.06-30.00 mm/min. Test results showed that residual strengths of SM-type landslide soils were not affected significantly by the over-consolidation process. The effect of shear rate on residual strength did not exhibit a regular pattern at shear rates of 0.06-10.00 mm/min, and behaved negatively at a high shear rate of 30 mm/min. The reduction in residual strength at higher shear rates may be attributable to increases in the water content of the shear zone and the amount of finer particles, due to particle breakage and/or larger grains being pushed from the shear zone.

  13. Lateral displacement of silty clay under cement-fly ash-gravel pile-supported embankments:Analytical consideration and field evidence

    Institute of Scientific and Technical Information of China (English)

    张崇磊; 蒋关鲁; 刘先峰; 王智猛

    2015-01-01

    Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported (GRPS) embankments was proposed. In order to validate the proposed method, a full-scale high-speed railway embankment (HSRE) with four instrumented subsections over medium compressibility silty clay was constructed in three stages. The soil profile, construction procedure and monitoring of settlements and lateral displacements of the four test sections were described. The field deformation analysis results show that 1) the combined reinforcement of CFG piles and geosynthetic layer perform well in terms of reducing lateral displacements;2) the development of lateral displacements lags behind the increase of fill load, which can be attributed to the vertical load transfer mechanism of the pile foundation;and 3) pile length has a dominant effect on the stress distribution proportion between piles and surrounding soils. The comparison between predicted and experimental results suggests that the proposed analytical solution and the back analysis-based method are capable of reasonably estimating the lateral deformation and the stress concentration ratio, respectively, if the appropriate soil elastic modulus is chosen.

  14. Spatial distribution of sandy desertificationchange in the west of Jilin Province

    Institute of Scientific and Technical Information of China (English)

    LIUHuiqing; XUJiawei; LVXinmiao

    2003-01-01

    The sandy land of the western part of Jilin Province is located in the ecotone of semi-humid and semi-arid area in the temperate zone of China. The sandy desertification has widely spread in the region because of the vulnerable natural conditions and the unreasonable human activity; as a result of this, the precious land resources and the economic development in the area have been seriously impacted. In this paper, the sandy land ecologic environment geographic information system is established based on the multi-spectral, multi-temporal Landsat TM images and field investigation. The comprehensive indexes of sandy desertification extent assessment which include vegetation degradation, wind erosion extent and soil depth are presented to classify the sandy land in western Jilin into three levels--slight, moderate and severe sandy desertification with the support of GIS platform. The results demonstrate that the sandy desertification has been partly controlled in the past twenty years, except some small sites. However, this doesn't necessarily mean that there is nothing for more concern. The two main causes of sandy desertification have not been eliminated yet, one is its natural factor, especially the physical and chemical characters of sandy soil and dry climate; another is the immoderate economic activity of human being that has highly accelerated the sandy desertification process.

  15. Rapid development of enhanced atrazine degradation in a Dundee silt loam soil under continuous corn and in rotation with cotton.

    Science.gov (United States)

    Zablotowicz, Robert M; Krutz, L Jason; Reddy, Krishna N; Weaver, Mark A; Koger, Clifford H; Locke, Martin A

    2007-02-07

    Mississippi Delta cotton (Gossypium hirsutum L.) production in rotation with corn (Zea mays L.) was evaluated in field experiments from 2000 to 2005 at Stoneville, Mississippi. Plots maintained under minimum tillage were established in 2000 on a Dundee silt loam with treatments including continuous cotton or corn and alternate cotton-corn rotations. Mineralization and dissipation of 14C [ring]-labeled atrazine were evaluated in the laboratory on soils collected prior to herbicide application in the first, second, third, and sixth years of the study. In soils collected in 2000, a maximum of 10% of the atrazine was mineralized after 30 days. After 1 year of herbicide application, atrazine-treated soils mineralized 52-57% of the radiolabeled atrazine in 30 days. By the sixth year of the study, greater than 59% of the atrazine was mineralized after 7 days in soils treated with atrazine, while soils from plots with no atrazine treatment mineralized less than 36%. The data also indicated rapid development of enhanced atrazine degradation in soils following 1 year of corn production with atrazine use. Atrazine mineralization was as rapid in soils under a rotation receiving biannual atrazine applications as in soils under continuous corn receiving annual applications of atrazine. Cumulative mineralization kinetics parameters derived from the Gompertz model (k and ti) were highly correlated with a history of atrazine application and total soil carbon content. Changes in the soil microbial community assessed by total fatty acid methyl ester (FAME) analysis indicated significant interactions of cropping system and sampling date, with FAME indicators for soil bacteria responsible for differences in community structure. Autoclaved soil lost all ability to mineralize atrazine, and atrazine-mineralizing bacteria were isolated from these plots, confirming the biological basis for atrazine mineralization. These results indicate that changes in degradative potential of a soil can

  16. Water level response in back-barrier bays unchanged following Hurricane Sandy

    Science.gov (United States)

    Aretxabaleta, Alfredo L.; Butman, Bradford; Ganju, Neil K.

    2014-01-01

    On 28–30 October 2012, Hurricane Sandy caused severe flooding along portions of the northeast coast of the United States and cut new inlets across barrier islands in New Jersey and New York. About 30% of the 20 highest daily maximum water levels observed between 2007 and 2013 in Barnegat and Great South Bay occurred in 5 months following Hurricane Sandy. Hurricane Sandy provided a rare opportunity to determine whether extreme events alter systems protected by barrier islands, leaving the mainland more vulnerable to flooding. Comparisons between water levels before and after Hurricane Sandy at bay stations and an offshore station show no significant differences in the transfer of sea level fluctuations from offshore to either bay following Sandy. The post-Hurricane Sandy bay high water levels reflected offshore sea levels caused by winter storms, not by barrier island breaching or geomorphic changes within the bays.

  17. Online Media Use and Adoption by Hurricane Sandy Affected Fire and Police Departments

    OpenAIRE

    Chauhan, Apoorva

    2014-01-01

    In this thesis work, I examine the use and adoption of online communication media by 840 fire and police departments that were affected by the 2012 Hurricane Sandy. I began by exploring how and why these fire and police departments used (or did not use) online media to communicate with the public during Hurricane Sandy. Results show that fire and police departments used online media during Hurricane Sandy to give timely and relevant information to the public about things such as evacuations, ...

  18. Morphology of rain water channelization in systematically varied model sandy soils

    OpenAIRE

    Wei, Y.; Cejas, C. M.; Barrois, R.; Dreyfus, R.; Durian, D. J.

    2014-01-01

    We visualize the formation of fingered flow in dry model sandy soils under different raining conditions using a quasi-2d experimental set-up, and systematically determine the impact of soil grain diameter and surface wetting property on water channelization phenomenon. The model sandy soils we use are random closely-packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates into a shallow top layer of soil and...

  19. Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms

    Directory of Open Access Journals (Sweden)

    Rebecca M. Schwartz

    2017-08-01

    Full Text Available Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130. There were statistically significant decreases in anxiety scores (mean difference = −0.33, p < 0.01 and post-traumatic stress disorder (PTSD scores (mean difference = −1.98, p = 0.001 between baseline and follow-up. Experiencing a combination of personal and property damage was positively associated with long-term PTSD symptoms (ORadj 1.2, 95% CI [1.1–1.4] but not with anxiety or depression. Having anxiety, depression, or PTSD at baseline was a significant predictor of persistent anxiety (ORadj 2.8 95% CI [1.1–6.8], depression (ORadj 7.4 95% CI [2.3–24.1 and PTSD (ORadj 4.1 95% CI [1.1–14.6] at follow-up. Exposure to Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

  20. Emergency evacuation orders: considerations and lessons from Hurricane Sandy.

    Science.gov (United States)

    O'Neil, Patrick D

    2014-01-01

    This article analyzes the problems surrounding the execution of emergency evacuation orders by evaluating Hurricane Sandy and the emergency actions taken by the State of New Jersey and the City of Atlantic City New Jersey. The analysis provides an overview of the legal authority granting emergency powers to governors and mayors to issue evacuation proclamations in addition to an evaluation of the New Jersey's emergency evacuation mandate and subsequent compliance. The article concludes with provision of planning and preparedness recommendations for public managers facing similar hazards, including a recommendation for provision of emergency shelter contingencies within the threat zone in anticipation of citizen noncompliance evacuation orders.

  1. Measured and Estimated Volatilisation of Naphthalene from a Sandy Soil

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Christensen, Thomas Højlund

    1994-01-01

    The non-steady-state fluxes of naphthalene from an artificially contaminated sandy soil at different water contents were measured in the laboratory, at 10°C. The soil contained 1.1% of organic carbon and the water content varied between 2.8 and 14% w/w. The diffusive flux of naphthalene from the ...... the fluxes by a factor of 1.5 to 6.4. The largest deviation between predicted and observed dynamic fluxes was found at high water contents. For the cover soil, half-life times of 1 to 2 days were estimated by the model for naphthalene degradation....

  2. Uncertainties in sandy shorelines evolution under the Bruun rule assumption

    Directory of Open Access Journals (Sweden)

    Gonéri eLe Cozannet

    2016-04-01

    Full Text Available In the current practice of sandy shoreline change assessments, the local sedimentary budget is evaluated using the sediment balance equation, that is, by summing the contributions of longshore and cross-shore processes. The contribution of future sea-level-rise induced by climate change is usually obtained using the Bruun rule, which assumes that the shoreline retreat is equal to the change of sea-level divided by the slope of the upper shoreface. However, it remains unsure that this approach is appropriate to account for the impacts of future sea-level rise. This is due to the lack of relevant observations to validate the Bruun rule under the expected sea-level rise rates. To address this issue, this article estimates the coastal settings and period of time under which the use of the Bruun rule could be (invalidated, in the case of wave-exposed gently-sloping sandy beaches. Using the sedimentary budgets of Stive (2004 and probabilistic sea-level rise scenarios based on IPCC, we provide shoreline change projections that account for all uncertain hydrosedimentary processes affecting idealized coasts (impacts of sea-level rise, storms and other cross-shore and longshore processes. We evaluate the relative importance of each source of uncertainties in the sediment balance equation using a global sensitivity analysis. For scenario RCP 6.0 and 8.5 and in the absence of coastal defences, the model predicts a perceivable shift toward generalized beach erosion by the middle of the 21st century. In contrast, the model predictions are unlikely to differ from the current situation in case of scenario RCP 2.6. Finally, the contribution of sea-level rise and climate change scenarios to sandy shoreline change projections uncertainties increases with time during the 21st century. Our results have three primary implications for coastal settings similar to those provided described in Stive (2004 : first, the validation of the Bruun rule will not necessarily be

  3. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  4. Removal of non aqueous phase liquid liquid (NAPL) from a loam soil monitored by time domain reflectometry (TDR) technique

    Science.gov (United States)

    comegna, alessandro; coppola, Antonio; dragonetti, giovanna; ajeel, ali; saeed, ali; sommella, angelo

    2016-04-01

    Non-aqueous phase liquids (NAPLs) are compounds with low or no solubility with water. These compounds, due to the several human activities, can be accidentally introduced in the soil system and thus constitute a serious geo-environmental problem, given the toxicity level and the high mobility. The remediation of contaminated soil sites requires knowledge of the contaminant distribution in the soil profile and groundwater. Methods commonly used to characterize contaminated sites are coring, soil sampling and the installation of monitoring wells for the collection of groundwater samples. The main objective of the present research is to explore the potential application of time domain reflectometry (TDR) technique in order to evaluate the effect of contaminant removal in a loam soil, initially contaminated with NAPL and then flushed with different washing solutions. The experimental setup consist of: i) a Techtronix cable tester; ii) a three-wire TDR probe with wave guides 14.5 cm long inserted vertically into the soil samples; iii) a testing cell of 8 cm in diameter and 15 cm high; iv) a peristaltic pump for upward injection of washing solution. In laboratory, soil samples were oven dried at 105°C and passed through a 2 mm sieve. Known quantities of soil and NAPL (corn oil, a non-volatile and non-toxic organic compound) were mixed in order to obtain soil samples with different degrees of contamination. Once a soil sample was prepared, it was repacked into a plastic cylinder and then placed into the testing cell. An upward injection of washing solution was supplied to the contaminated sample with a rate q=1.5 cm3/min, which corresponds to a darcian velocity v=6.0 cm/h. The out coming fluid, from the soil column was collected, then the washing solution and oil was separated. Finally both the amount of oil that was remediated and the dielectric permittivity (measured via TDR) of the contaminated soil sample were recorded. Data collected were employed to implement a

  5. Weeds of cereal stubble-fields on various soils in the Kielce region. P. 1. Podzolic and brown soils developed from sands and loams

    Directory of Open Access Journals (Sweden)

    Franciszek Pawłowski

    2013-12-01

    Full Text Available Occupying cereal stubble-fields weed flora is the most characteristic of the environmental (especially soil conditions. Because of its developing and accomplishing the reproductive stages there it can threatens cultivated plants. They are considered to complete the seed store in a soil by 393 min per ha. The results presented in the paper concern the species composition, number and constancy (S and indice of coverage (D of the cereal stubble-field weed species on various soils in the Kielce region (the central part of Poland. The report was based upon 885 phytosociological records collected in the 268 stands. The records were carried out after the crop harvest, in the latter part of September, in 1976-1980. Soil were chosen on the base of soil maps. The analyse of soil samples, taken at the investigation process, were done in order to confirm the soil quality. The worked out material was divided into three parts. The first part, including 369 phytosociological records collected in the 112 stands (in 90 localities concerns stubble-field weeds on podzolic and brown soils developed from sands (loose, weakly loamy and loamy and loams (light and medium. It was found that these soils were grown by 108 (loamy sands to 132 (weakly loamy sands weed species. Among them 66 species were common for all of the soils. Species composition was not differentiated by the soil type (brown, podzolic within kind of the. soil (sand or loams. Among soil examined, the brown loams was the most abundant with species of high constancy degree (30 species but brown loose sands and podzolic loamy sands was the poorest one with (16 species.

  6. Changes to soil water content and biomass yield under combined maize and maize-weed vegetation with different fertilization treatments in loam soil

    Directory of Open Access Journals (Sweden)

    Lehoczky Éva

    2016-06-01

    Full Text Available Especially during early developmental stages, competition with weeds can reduce crop growth and have a serious effect on productivity. Here, the effects of interactions between soil water content (SWC, nutrient availability, and competition from weeds on early stage crop growth were investigated, to better understand this problem. Field experiments were conducted in 2013 and 2014 using long-term study plots on loam soil in Hungary. Plots of maize (Zea mays L. and a weed-maize combination were exposed to five fertilization treatments. SWC was observed along the 0–80 cm depth soil profile and harvested aboveground biomass (HAB was measured.

  7. Mental health outcomes at the Jersey Shore after Hurricane Sandy.

    Science.gov (United States)

    Boscarino, Joseph A; Hoffman, Stuart N; Kirchner, H Lester; Erlich, Porat M; Adams, Richard E; Figley, Charles R; Solhkhah, Ramon

    2013-01-01

    On October 29, 2012, Hurricane Sandy made landfall in the most densely populated region in the US. In New Jersey, thousands of families were made homeless and entire communities were destroyed in the worst disaster in the history of the state. The economic impact of Sandy was huge, comparable to Hurricane Katrina. The areas that sustained the most damage were the small- to medium-sized beach communities along New Jersey's Atlantic coastline. Six months following the hurricane, we conducted a random telephone survey of 200 adults residing in 18 beach communities located in Monmouth County. We found that 14.5% (95% CI = 9.9-20.2) of these residents screened positive for PTSD and 6.0% (95% CI = 3.1-10.2) met criteria for major depression. Altogether 13.5% (95% CI = 9.1-19.0) received mental health counseling and 20.5% (95% CI = 15.1-26.8) sought some type of mental health support in person or online, rates similar to those reported in New York after the World Trade Center disaster In multivariate analyses, the best predictors of mental health status and service use were having high hurricane exposure levels, having physical health limitations, and having environmental health concerns. Research is needed to assess the mental health status and service use of Jersey Shore residents over time, to evaluate environmental health concerns, and to better understand the storm's impact among those with physical health limitations.

  8. The bioremediation potential of marine sandy sediment microbiota

    Directory of Open Access Journals (Sweden)

    Dan Răzvan POPOVICIU

    2012-11-01

    Full Text Available The natural microbiota from marine sandy sediments on the Romanian sea coast was tested for resilience in case of hydrocarbon contamination, for estimating the number of (culturable hydrocarbon and lipid oil-degrading microorganisms and for determining the influence of inorganic nitrate and phosphate nutrients on hydrocarbon spill bioremediation process, by microcosm experiments.Results show that hydrocarbon contamination affects the bacteriobenthos both in terms of cell numbers and composition. Bacterial numbers showed a rapid decrease (28% in four days, followed by a relatively fast recovery (two weeks. The pollution favoured the increase of Gram-positive bacterial proportion (from around 25% to 33%Sandy sediment microbiota in both sites studied contained microorganisms able to use mineral or lipid oils as sole carbon sources, usually around 103-104/cm3, with variations according to the sediment grain size and substrate used.The biostimulation experiments showed that, in absence of water dynamism (and, implicitly, an efficient oxygenation, the addition of nitrogen and phosphorus can be ineffective and even inhibit the remediation process, probably due to eutrophication.

  9. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems

    Science.gov (United States)

    Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar

    2016-10-01

    Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.

  10. A Coordinated USGS Science Response to Hurricane Sandy

    Science.gov (United States)

    Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.

    2013-12-01

    In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as

  11. Coastal topography–Northeast Atlantic coast, post-hurricane Sandy, 2012

    Science.gov (United States)

    Stockdon, Hilary F.; Doran, Kara S.; Sopkin, Kristin L.; Smith, Kathryn E.L.; Fredericks, Xan

    2013-01-01

    This Data Series contains lidar-derived bare-earth (BE) topography, dune elevations, and mean-high-water shoreline position datasets for most sandy beaches for Fire Island, New York, and from Cape Henlopen, Delaware to Cape Lookout, North Carolina. The data were acquired post-Hurricane Sandy, which made landfall as an extratropical cyclone on October 29, 2012.

  12. Abrasive wear based predictive maintenance for systems operating in sandy conditions

    NARCIS (Netherlands)

    Woldman, M.; Tinga, T.; Heide, E. van der; Masen, M.A.

    2015-01-01

    Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be fulfille

  13. Heterogeneous water flow and pesticide transport in cultivated sandy soils : description of model concepts

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2011-01-01

    There is ample experimental evidence that complications in water flow and pesticide transport can occur in cultivated humic-sandy and loamy-sandy soils. As a result, pesticide leaching to groundwater and water courses can be higher than expected. We made an inventory of mechanistic/deterministic mod

  14. Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

    DEFF Research Database (Denmark)

    Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico;

    2013-01-01

    In this paper an imaging system for measuring sandy bottom dynamics is proposed. The system exploits stereo sequences and projected laser beams to build the 3D shape of the sandy bottom during time. The reconstruction is used by experts of the field to perform accurate measurements and analysis i...

  15. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther

    2000-01-01

    belonging to Platyhelminthes, Rotifera, Gastrotricha, and Protodriloidae (Polychaeta) occurred only at the sandy locality, whereas Kinorhyncha, Foraminifera, and Cumacea (Crustacea) occurred only at the muddy stations. The larger number of meiofauna individuals at the sandy locality may in part be explained...

  16. Nitrate leaching to groundwater at experimental farm "De Marke" and other Dutch sandy soils

    NARCIS (Netherlands)

    Hack-ten Broeke, M.J.D.

    2001-01-01

    This study focuses on nitrate leaching to the groundwater as a result of the land use system of experimental farm 'De Marke', translated to other sandy soils in the Netherlands. The land use was extrapolated to five major sandy soil map units, selected from the 1: 50 000 Soil Map of the Netherlands,

  17. 33 CFR 80.170 - Sandy Hook, NJ to Tom's River, NJ.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sandy Hook, NJ to Tom's River, NJ. 80.170 Section 80.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.170 Sandy Hook, NJ to Tom's River...

  18. Study on Improved Physical Properties of Aeolian Sandy Soil with Fly Ash%利用粉煤灰改良风沙土物理性质的研究

    Institute of Scientific and Technical Information of China (English)

    李占宏; 白守德; 崔志永; 高将

    2011-01-01

    [Objective]The aim was to research the effective measure of the improved physical properties of Aeolian sandy soil with fly ash. [ Method] Based on the analysis of the structure and physical properties of Aeolian sandy soil and fly ash,and the measurement of particle size range of test sample, soil proportion, soil bulk density and porosity the matching soil proportion, soil bulk density, porosity and water physical properties changes of fly ash of imposing different application rates to Aeolian sandy soil were studied. [ Result] The sandy soil by mixing fly ash increased Aeolian sandy soil clay, reduced soil bulk density and porosity coefficient. Contrasting four kinds of allocated proportion plans, optimal application rate of Aeolian sandy soil with fly ash was 30%. The fly ash with optimal application rate could effectively improve the soil physical traits. Soil permeability and water holding capacity was close to 1-2. Pore-size was between 50% and 60% , with the characteristics of loam. Soil moisture of fly ash in the soil significantly improved compared with sand, the permeability increased unceasingly, and effective water stranded time increased. [ Conclusion ] The research provided support for the improvement of physical properties of Aeolian sandy soil with fly ash.%[目的]研究粉煤灰改良风沙土物理性质的有效性.[方法]在测量供试样品的粒径范围、土壤比重、容重,孔隙度的基础上,对风沙土添加不同用量的粉煤灰并调控测试条件,研究了不同土壤样品的比重、容重,孔隙度及水分物理性质的变化情况.[结果]风沙土中掺入粉煤灰使风沙土黏粒含量增多,土壤容重、孔隙度降低,风沙土与粉煤灰最优的添加率为30%.30%添加率可有效改良土壤物理性状,土壤透水性与持水性约1∶2,孔隙度为50% ~ 60%,具有壤土的特点,其含水率较沙土有明显提高,渗透性不断升高,有效水分滞留时间增加.[结论]该研究为利

  19. Seasonal variation of bivalve larvae on an exposed sandy beach on Kashima-nada: Tips for the sandy beach recruitment process

    Science.gov (United States)

    Sawada, Hideki; Saito, Hajime; Adachi, Kumiko; Toyohara, Haruhiko

    2011-02-01

    Bivalves are often the dominant macrobenthos species in exposed sandy beach environments. However, our understanding of their recruitment processes before post-settlement stages on sandy beaches with highly energetic environments is incomplete. To clarify the characteristics of the free-swimming planktonic stage that affects recruitment efficiency in sandy shore ecosystems, we investigated the temporal (weekly-biweekly) variation of bivalve planktonic larval concentration coupled with oceanographic conditions on an exposed sandy shore on the sea of Kashima-nada, Japan, from summer 2003 to autumn 2005. Larvae were observed throughout the year, but the surge of larval concentration composed of sandy beach and sessile bivalves occurred most prominently in summer, from August to September. The peak concentration of larvae during this season was more than 1000 times higher than in other seasons. The larval concentration was positively correlated with water temperature and northward wind velocity and negatively correlated with each of the nutrient concentrations. On the other hand, chlorophyll a concentration and salinity seemed to have little effect on the larval concentration. Based on this fundamental knowledge, further investigations about planktonic larvae in sandy beaches are needed.

  20. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar point-cloud data (LAS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  1. Progress in sandy desertification research of China%中国沙漠化研究进展

    Institute of Scientific and Technical Information of China (English)

    王涛

    2004-01-01

    Sandy desertification is land degradation characterized by wind erosion mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in northern China. The research on sandy desertification has experienced more than 5 decades of arduous course of the struggle along with the establishment and development of China′s desert science. Researches in this field have made a great contribution to the national economic construction, and environmental protection. This paper focuses on presenting the major progress and achievements in the sandy desertification research during the last 50 years, including the stages of study on sandy desertification,background environment of sandy desertification and its changes, the conception, causes, process,monitoring and assessment of sandy desertification, the vegetation succession, landscape ecology, plant physiology, impacts on ecosystem, high-effective use of water and land resources and sustainable development in sandy desertified regions, sandy desertification control models and techniques etc.

  2. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar point-cloud data (LAS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  3. Pine Woodchip Biochar Impact on Soil Nutrient Concentrations and Corn Yield in a Silt Loam in the Mid-Southern U.S.

    Directory of Open Access Journals (Sweden)

    Katy E. Brantley

    2015-02-01

    Full Text Available Biochar has altered plant yields and soil nutrient availability in tropical soils, but less research exists involving biochar additions to temperate cropping systems. Of the existing research, results vary based on soil texture, crop grown, and biochar properties. The objective of this study was to determine the effects of pine (Pinus spp. woodchip biochar at 0, 5, and 10 Mg·ha−1 rates combined with urea nitrogen (N on soil chemical properties and corn (Zea mays L. yield under field conditions in the first growing season after biochar addition in a silt-loam alluvial soil. Biochar combined with fertilizer numerically increased corn yields, while biochar alone numerically decreased corn yields, compared to a non-amended control. Corn nitrogen uptake efficiency (NUE was greater with 10 Mg·ha−1 biochar compared to no biochar. There were limited biochar effects on soil nutrients, but biochar decreased nitrate, total dissolved N, and Mehlich-3 extractable sulfur and manganese concentrations in the top 10 cm. Pine woodchip biochar combined with N fertilizer has the potential to improve corn production when grown in silt-loam soil in the mid-southern U.S. by improving NUE and increasing yield. Further research will be important to determine impacts as biochar ages in the soil.

  4. Study on Triaxial Creep Test of Silty Mudstone%粉砂质泥岩的三轴蠕变试验研究

    Institute of Scientific and Technical Information of China (English)

    徐慧宁; 庞希斌; 徐进; 刘建锋

    2012-01-01

    为了揭示分布于北天山中西部的志留系上统紫红色粉砂质泥岩的蠕变特性,为拟建于此的某深埋越岭特长隧洞的设计、施工,以及长期稳定问题评价提供依据,通过钻孔取样进行了三轴蠕变试验研究。试验在5台岩石三轴蠕变试验机上进行,围压分别为0、5、102、03、0 MPa。试验取得以下主要成果:1)揭示了这类黏土岩的蠕变特性可用西原模型加以描述,并由此建立了蠕变本构方程;2)采用曲线求参法求解了各流变参数;3)采用叠加原理与等时曲线法获得了岩石的长期强度;4)各蠕变参数随围压的升高而增大,长期强度较瞬时强度降低的幅度亦随围压升高而增大,单轴条件下降低25%,30MPa围压时降低52%;5)抗剪断长期强度较瞬时强度降低了60%(内聚力)和36%(内摩擦角)。这些成果为工程建设提供了科学依据,试验方法与成果整理方法可供同类工程参考。同时,还通过常规试验获得了该类岩石的主要物理力学性能,这将有助于蠕变试验成果在其他工程中类比使用。%Tri-axial creep test was carried out on borehole sampling basis in order to reveal the creep characteristics of purple silty mudstone in the Upper Silurian in the center and west of North Tianshan,and provide the basis for the designing,construction and long-term stability evaluation of the proposed deep and long tunnel.Test was performed on five rock tri-axial creep test machines with the confining pressure of 0,5,10,20 and 30 MPa,respectively.Through the study,the following resulted were achieved.Rock creep characteristics was proved to be describable by the Xiyuan Model and a creep constitutive equation was establish for this kind of mudstone.The creep parameters were gained by calculating them based on creep curves.Long-term rock strength was obtained by superposition theorem and isochronous curve method,and the confining pressure effect was revealed on

  5. Hurricane Sandy: Shared Trauma and Therapist Self-Disclosure.

    Science.gov (United States)

    Rao, Nyapati; Mehra, Ashwin

    2015-01-01

    Hurricane Sandy was one of the most devastating storms to hit the United States in history. The impact of the hurricane included power outages, flooding in the New York City subway system and East River tunnels, disrupted communications, acute shortages of gasoline and food, and a death toll of 113 people. In addition, thousands of residences and businesses in New Jersey and New York were destroyed. This article chronicles the first author's personal and professional experiences as a survivor of the hurricane, more specifically in the dual roles of provider and trauma victim, involving informed self-disclosure with a patient who was also a victim of the hurricane. The general analytic framework of therapy is evaluated in the context of the shared trauma faced by patient and provider alike in the face of the hurricane, leading to important implications for future work on resilience and recovery for both the therapist and patient.

  6. Performance of social network sensors during Hurricane Sandy.

    Directory of Open Access Journals (Sweden)

    Yury Kryvasheyeu

    Full Text Available Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the "friendship paradox", is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users' network centrality effectively translate into moderate awareness advantage (up to 26 hours; and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple "sentiment sensing" technique that can detect and locate disasters.

  7. Performance of social network sensors during Hurricane Sandy.

    Science.gov (United States)

    Kryvasheyeu, Yury; Chen, Haohui; Moro, Esteban; Van Hentenryck, Pascal; Cebrian, Manuel

    2015-01-01

    Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the "friendship paradox", is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users' network centrality effectively translate into moderate awareness advantage (up to 26 hours); and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple "sentiment sensing" technique that can detect and locate disasters.

  8. Public support for policies to reduce risk after Hurricane Sandy.

    Science.gov (United States)

    Greenberg, Michael R; Weiner, Marc D; Noland, Robert; Herb, Jeanne; Kaplan, Marjorie; Broccoli, Anthony J

    2014-06-01

    A phone survey was conducted in New Jersey in 2013 four months after the second of two major devastating tropical storms (Sandy in 2012 and Irene in 2011). The objective was to estimate public support for restricting land uses in flood zones, requiring housing to be built to resist storm waters, and otherwise increasing mitigation and resilience. Respondents who supported these mitigation and resilience policies disproportionately were concerned about global climate change, trusted climate scientists and the federal government, and were willing to contribute to a redevelopment program through taxes, bonds, and fees. They also tended to have collectivist and egalitarian worldviews. Half of the respondents supported at least four of the seven risk-reducing policies. How their support translates into public policy remains to be seen. Lack of willingness to personally fund these policies is an obstacle.

  9. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.

    2000-01-01

    ; Zn: 6±22,800 l/kg) and correlating them to the characteristics of the aquifer material (particle size distribution, organic C content, surface area, pH) revealed good correlation with pH in the range 5.3± 8.9 (Cu: r 2=0.72; Zn: r 2=0.94). Including any other of the measured aquifer characteristics...... improved the correlation only a few percent. The results indicate that the mobility of Cu and Zn in sandy aquifers, as re¯ected in the measured Kd values, is very restricted at pH values above 6, since the relative migration velocity is less than 1%. However, at lower pH values, Zn seems to become mobile...

  10. Remediation of sandy soils using surfactant solutions and foams.

    Science.gov (United States)

    Couto, Hudson J B; Massarani, Guilio; Biscaia, Evaristo C; Sant'Anna, Geraldo L

    2009-05-30

    Remediation of sandy soils contaminated with diesel oil was investigated in bench-scale experiments. Surfactant solution, regular foams and colloidal gas aphrons were used as remediation fluids. An experimental design technique was used to investigate the effect of relevant process variables on remediation efficiency. Soils prepared with different average particle sizes (0.04-0.12 cm) and contaminated with different diesel oil contents (40-80 g/kg) were used in experiments conducted with remediation fluids. A mathematical model was proposed allowing for the determination of oil removal rate-constant (k(v)) and oil content remaining in the soil after remediation (C(of)) as well as estimation of the percentage of oil removed. Oil removal efficiencies obtained under the central experimental design conditions were 96%, 88% and 35% for aphrons, regular foams and surfactant solutions, respectively. High removal efficiencies were obtained using regular foams and aphrons, demanding small amounts of surfactant.

  11. Visual Odometry for Planetary Exploration Rovers in Sandy Terrains

    Directory of Open Access Journals (Sweden)

    Linhui Li

    2013-05-01

    Full Text Available Visual odometry provides planetary exploration rovers with accurate knowledge of their position and orientation, which needs effective feature tracking results, especially in barren sandy terrains. In this paper, a stereovision based odometry algorithm is proposed for a lunar rover, which is composed of corner extraction, feature tracking and motion estimation. First, a morphology based image enhancement method is studied to guarantee enough corners are extracted. Second, a Random Sample Consensus (RANSAC algorithm is proposed to make a robust estimation of the fundamental matrix, which is the basic and critical part of feature matching and tracking. Then, the 6 degrees of freedom rover position and orientation is estimated by the RANSAC algorithm. Finally, experiments are performed in a simulated lunar surface environment using a prototype rover, which have confirmed the feasibility and effectiveness of the proposed method.

  12. Performance of Social Network Sensors during Hurricane Sandy

    Science.gov (United States)

    Kryvasheyeu, Yury; Chen, Haohui; Moro, Esteban; Van Hentenryck, Pascal; Cebrian, Manuel

    2015-01-01

    Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the “friendship paradox”, is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users’ network centrality effectively translate into moderate awareness advantage (up to 26 hours); and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple “sentiment sensing” technique that can detect and locate disasters. PMID:25692690

  13. Nematode Faunal Response to Grassland Degradation in Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The responses of soil nematode communities to grassland degradation were studied under undegraded grassland (UG),degraded grassland (DG), and improved grassland (IG), in Horqin Sandy Land, Inner Mongolia, Northeast China. Soil samples were collected at depths of 0-10, 10-20, and 20-30 cm. Total organic carbon (TOC) and total nitrogen (TN)exhibited positive effects on the total number of nematodes and trophic groups. Significant treatment effects were found in the total number of nematodes, plant parasites, and omnivores-predators. Measures taken in the improved grassland could improve the number of omnivore-predators, especially in the deeper soil layers. Nematode richness was lower in the DG treatment than in the IG and UG treatments. The food web structure index (SI) was significantly higher in the UG and IG treatments than in the DG treatment. A higher SI suggested a food web with more trophic linkages and relatively healthy ecosystems.

  14. Extraction Efficiency of Belonolaimus longicaudatus from Sandy Soil.

    Science.gov (United States)

    McSorley, R; Frederick, J J

    1991-10-01

    Numbers of Belonolaimus longicaudatus extracted from sandy soils (91-92% sand) by sieving and centrifugation were only 40-55% of those extracted by sieving and incubation on a Baermann tray. Residues normally discarded at each step of the sieving plus Baermann tray extraction procedure were examined for nematodes to obtain estimates of extraction efficiencies. For third-stage and fourth-stage juveniles, males, and females, estimates of extraction efficiency ranged from 60 to 65% in one experiment and 73 to 82% in another. Estimated extraction efficiencies for second-stage juveniles were lower (33% in one experiment, 67% in another) due to losses during sieving. When sterilized soil was seeded with known numbers of B. longicaudatus, 60% of second-stage juveniles and 68-76% of other stages were recovered. Most stages of B. longicaudatus could be extracted from these soils by sieving plus Baermann incubation with an efficiency of 60-70%.

  15. 78 FR 52560 - Hurricane Sandy Rebuilding Task Force-Rebuild-by-Design; Announcement of Selection of Design Teams

    Science.gov (United States)

    2013-08-23

    ... URBAN DEVELOPMENT Hurricane Sandy Rebuilding Task Force--Rebuild-by-Design; Announcement of Selection of Design Teams AGENCY: Hurricane Sandy Task Force, HUD. ACTION: Notice. SUMMARY: In June 2013, the Hurricane Sandy Task Force launched Rebuild by Design, a multi-stage regional design competition to...

  16. Quantifying human mobility perturbation and resilience in Hurricane Sandy.

    Science.gov (United States)

    Wang, Qi; Taylor, John E

    2014-01-01

    Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  17. Glider observations and modeling of sediment transport in Hurricane Sandy

    Science.gov (United States)

    Miles, Travis; Seroka, Greg; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2015-03-01

    Regional sediment resuspension and transport are examined as Hurricane Sandy made landfall on the Mid-Atlantic Bight (MAB) in October 2012. A Teledyne-Webb Slocum glider, equipped with a Nortek Aquadopp current profiler, was deployed on the continental shelf ahead of the storm, and is used to validate sediment transport routines coupled to the Regional Ocean Modeling System (ROMS). The glider was deployed on 25 October, 5 days before Sandy made landfall in southern New Jersey (NJ) and flew along the 40 m isobath south of the Hudson Shelf Valley. We used optical and acoustic backscatter to compare with two modeled size classes along the glider track, 0.1 and 0.4 mm sand, respectively. Observations and modeling revealed full water column resuspension for both size classes for over 24 h during peak waves and currents, with transport oriented along-shelf toward the southwest. Regional model predictions showed over 3 cm of sediment eroded on the northern portion of the NJ shelf where waves and currents were the highest. As the storm passed and winds reversed from onshore to offshore on the southern portion of the domain waves and subsequently orbital velocities necessary for resuspension were reduced leading to over 3 cm of deposition across the entire shelf, just north of Delaware Bay. This study highlights the utility of gliders as a new asset in support of the development and verification of regional sediment resuspension and transport models, particularly during large tropical and extratropical cyclones when in situ data sets are not readily available.

  18. Revealing accumulation zones of plastic pellets in sandy beaches.

    Science.gov (United States)

    Moreira, Fabiana T; Balthazar-Silva, Danilo; Barbosa, Lucas; Turra, Alexander

    2016-11-01

    Microplastics such as pellets are reported worldwide on sandy beaches, and have possible direct and indirect impacts on the biota and physical characteristics of the habitats where they accumulate. Evaluations of their standing stock at different spatial scales generate data on levels of contamination. This information is needed to identify accumulation zones and the specific beach habitats and communities that are likely to be most affected. Standing stocks of plastic pellets were evaluated in 13 sandy beaches in São Paulo state, Brazil. The sampling strategy incorporated across-shore transects from coastal dunes and backshores, and vertical profiles of the accumulated pellets down to 1 m depth below the sediment surface. Accumulation zones were identified at regional (among beaches) and local (between compartments) scales. At the regional scale pellet density tended to increase at beaches on the central and southwestern coast, near ports and factories that produce and transport the largest amounts of pellets in the country. At the local scale coastal dunes showed larger accumulations of pellets than backshores. For both compartments pellets tended to occur deeper in areas where standing stocks were larger. Most of the pellets were concentrated from the surface down to 0.4 m depth, suggesting that organisms inhabiting this part of the sediment column are more exposed to the risks associated with the presence of pellets. Our findings shed light on the local and regional scales of spatial variability of microplastics and their consequences for assessment and monitoring schemes in coastal compartments. Copyright © 2016. Published by Elsevier Ltd.

  19. High-density turbidity currents: Are they sandy debris flows?

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

    1996-01-01

    Conventionally, turbidity currents are considered as fluidal flows in which sediment is supported by fluid turbulence, whereas debris flows are plastic flows in which sediment is supported by matrix strength, dispersive pressure, and buoyant lift. The concept of high-density turbidity current refers to high-concentration, commonly non-turbulent, flows of fluids in which sediment is supported mainly by matrix strength, dispersive pressure, and buoyant lift. The conventional wisdom that traction carpets with entrained turbulent clouds on top represent high-density turbidity currents is a misnomer because traction carpets are neither fluidal nor turbulent. Debris flows may also have entrained turbulent clouds on top. The traction carpet/debris flow and the overriding turbulent clouds are two separate entities in terms of flow rheology and sediment-support mechanism. In experimental and theoretical studies, which has linked massive sands and floating clasts to high-density turbidity currents, the term high-density turbidity current has actually been used for laminar flows. In alleviating this conceptual problem, sandy debris flow is suggested as a substitute for high-density turbidity current. Sandy debris flows represent a continuous spectrum of processes between cohesive and cohesionless debris flows. Commonly they are rheologically plastic. They may occur with or without entrained turbulent clouds on top. Their sediment-support mechanisms include matrix strength, dispersive pressure, and buoyant lift. They are characterized by laminar flow conditions, a moderate to high grain concentration, and a low to moderate mud content. Although flows evolve and transform during the course of transport in density-stratified flows, the preserved features in a deposit are useful to decipher only the final stages of deposition. At present, there are no established criteria to decipher transport mechanism from the depositional record.

  20. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    Science.gov (United States)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  1. Quantifying human mobility perturbation and resilience in Hurricane Sandy.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  2. Assessment of sandy desertification trends in the Shule River Basin from 1978 to 2010

    Institute of Scientific and Technical Information of China (English)

    Xiang Song; ChangZhen Yan; Sen Li; JiaLi Xie

    2014-01-01

    Sandy desertification in the Shule River Basin has expanded dramatically during the past 30 years. We evaluated the status, evolution, and main causes of sandy desertification by interpreting Landsat images which were acquired in 1978, 1990, 2000, 2005, and 2010, and analyzing the relevant meteorological data. The results show there was 3,477.95 km2, 3,733.32 km2, 3,620.29 km2, 3,565.65 km2, and 3,557.88 km2 of sandy desertified land in 1978, 1990, 2000, 2005, and 2010, respectively. From 1978 to 1990, not only the area of sandy desertified land (SDL) but also the degree of SDL levels increased. From 1990 to 2010 there was widespread restoration of SDL but the recovery trend of SDL gradually slowed. Although climate change contributes to expanding sandy desertification, human activities can either accelerate or reverse trends of natural sandy desertification. Some detrimental human activities can accelerate sandy desertification, but, conversely, desertification control measures such as the Three-North Shelter Forest Project and watershed rehabilitation programs in areas including the Shule River Basin resulted in many SDL being turned into grasslands or forest lands when shrubs and trees were planted to fix mobile sands at the edges of oases and cities. With population growth, much SDL has been reclaimed as farm land using water-saving agricultural methods or has been turned into built-up land as a result of urbanization.

  3. Field investigation of surface sand and dust movement over different sandy grasslands in the Otindag Sandy Land, China

    Science.gov (United States)

    Liu, Shulin; Wang, Tao; Chen, Guangting; Guo, Jian; Xue, Xian; Ma, Shaoxiu

    2008-01-01

    The characteristics of sand and dust movement over different sandy grasslands in China’s Otindag Sandy Land were explored based on field observations and laboratory analyses. Threshold wind speeds (the speed required to initiate sand movement) at a height of 2 m above the ground were estimated in the field for different surface types. Threshold wind speed above shifting dunes in the study area is about 4.6 m s-1 at this height. This value was smaller than values observed above other surfaces, resulting in a greater risk of blowing sand above these dunes. Differences in sand transport rates (STR) as a function of the severity of desertification resulted primarily from differences in surface vegetation cover and secondarily from the soil’s grain-size distribution. STR increased exponentially with increasing near-bed wind velocity. Under the same wind conditions, STR increased with increasing severity of desertification: from 0.08 g cm-2 min-1 above semi-fixed dunes to 8 g cm-2 min-1 above semi-shifting dunes and 25 g cm-2 min-1 above shifting dunes. Vegetation’s affect on STR was clearly large. Different components of sand and dust were trapped over different lands: mostly sand grains but little dust were trapped above shifting dunes, but much dust was collected over semi-shifting and semi-fixed dunes. Human disturbance is likely to produce dust even from fixed dunes as a result of trampling by animals and vehicle travel. In addition, spring rainfall decreased the risk of sand and dust movement by accelerating germination of plants and the formation of a soil crust.

  4. A geophysical and biochemical investigation of buried remains in contrasting soil textures in southern Ontario

    Science.gov (United States)

    Lowe, Amanda C.

    Ground penetrating radar (GPR) is a non-invasive, geophysical tool used for the detection of clandestine graves. GPR operates by detecting density differences in soil by the transmission of high frequency electromagnetic (EM) waves from an antenna. A 500 Megahertz (MHz) frequency antenna is typically used for forensic investigations, as it provides a suitable compromise between depth of penetration and sub-surface resolution. Domestic pig (Sus scrofa) carcasses were clothed in 100% cotton t-shirts and 50% cotton/50% polyester briefs, and buried at a consistent depth at three field sites of contrasting soil texture (silty clay loam, fine sand and fine sandy loam) in southern Ontario. GPR was used to detect and monitor the graves for a period of 14 months post burial. Analysis of collected data revealed that GPR had applicability in the detection of clandestine graves containing remains in silty clay loam and fine sandy loam soils, but was not suitable for detection in fine sandy soil. Specifically, within a fine sandy loam soil, there is the potential to estimate the post burial interval (PBI), as hyperbolic grave response was well defined at the beginning of the 14 month burial duration, but became less distinctive near the completion of the study. Following the detection of a clandestine grave containing a carcass, collection of gravesoil, tissue and textile samples is important for the estimation of the stage of decomposition and the post burial interval (PBI) of the remains. Throughout the decomposition process of a carcass, adipose tissue is subjected to hydrolytic enzymes that convert triglycerides to their corresponding unsaturated, saturated and salts of fatty acids. The composition of fatty acids in the decomposed tissue will vary with the post mortem period, but it is unknown what affect the soil texture has on lipid degradation. As decomposition proceeds, fatty acids can leach from the tissues into the surrounding burial environment. Fatty acid analysis

  5. 振冲碎石桩加固高层建筑粉砂土地基实例分析%Case Study on Improving Silty Sand Foundation of Tall Building by Vibro-replacement Stone Column

    Institute of Scientific and Technical Information of China (English)

    谢新宇; 应宏伟; 夏建中

    2001-01-01

    In this paper, the case studies of two tall buildings built on silty sand improved by vibro-replacement stone column in Hangzhou are reported. The design and computation method for vibro-replacement stone column composite foundation are introduced. Based on field testing results,the construction techniques of vibro-replacement stone column and the appraisement of improvement effect are discussed. It is the first time that the vibro-replacement stone column method has been successfully applied to improve silty sand foundation of tall building in Hangzhou.%本文介绍杭州两座高层建筑物采用振冲碎石桩加固粉砂土地基的工程实例。结合有关现场测试成果,探讨了高层建筑振冲碎石桩地基设计计算、振冲碎石桩施工控制和加固效果评价等有关问题。为振冲碎石桩在同类地基中的推广应用提供一些成功经验。

  6. Content Analysis of Select YouTube Postings: Comparisons of Reactions to the Sandy Hook and Aurora Shootings and Hurricane Sandy.

    Science.gov (United States)

    Miller, Eric D

    2015-11-01

    This study details an innovative and methodical content analysis of 2,207 YouTube comments from four different YouTube videos (e.g., breaking news or memorials) related to the 2012 Sandy Hook Elementary School and Aurora theater mass shootings and the catastrophic Hurricane Sandy. As expected, YouTube comments associated with the Sandy Hook shootings (particularly those from a memorial video) were especially likely to feature compassion and grief with lessened hostility. This study highlights differing online contexts by which individuals show grief and related emotions following man-made and natural calamities and how-even in an online environment-powerful situational contexts greatly guide behavior.

  7. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  8. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  9. 78 FR 19357 - Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy

    Science.gov (United States)

    2013-03-29

    ... significant spending cuts known as sequestration and is unavailable for Hurricane Sandy disaster relief. The... January 29, 2013. FTA announced individual allocations on a rolling basis beginning March 6, 2013. Table...

  10. 2012-2013 Post-Hurricane Sandy EAARL-B Submerged Topography - Barnegat Bay, New Jersey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data for part of Barnegat Bay, New Jersey, post-Hurricane Sandy (October 2012 hurricane), were produced from remotely sensed, geographically...

  11. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  12. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  13. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  14. 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New Jersey CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  15. 2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.35m GSD created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in Hurricane Sandy coastal...

  16. Quantitative Retrieval of Soil Nutrient in Sandy Land Based on BJ-1 Multispectral Image

    Science.gov (United States)

    Wu, Junjun; Li, Zengyuan; Gao, Zhihai; Wang, Bengyu; Bai, Lina; Sun, Bin; Li, Changlong; Ding, Xiangyuan

    2014-11-01

    To research an indicator for sandy information, this paper conducts a study on soil nutrient in sandy land. Firstly, the difference of soil nutrient between sandy land and the other was analyzed. Secondly, the correlation between soil nutrient index and band was studied. Then the best inversion band and model was determined and evaluated. Finally, the distribution of soil nutrient was obtained. As the result indicated that the divergence of total nitrogen in different land was the maximum among the three nutrient indicators. With the development of desertification, total nitrogen declined dramatically. The correlation coefficient between each band and total nitrogen was relatively higher, and it reached 0.6. In addition, taking the reciprocal for the sum of three bands as the independent variable was an excellent choice, it could reflect the sandy information better than the single band. The quantitative retrieval model was checked by independent sample, and RMSE was 0.0407.

  17. 2012 USGS EAARL-B Coastal Topography: Post-Sandy, First Surface (NJ)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  18. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  19. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  20. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  1. Colonization dynamics of ciliate morphotypes modified by shifting sandy sediments.

    Science.gov (United States)

    Risse-Buhl, Ute; Felsmann, Katja; Mutz, Michael

    2014-08-01

    Sandy stream-bed sediments colonized by a diverse ciliate community are subject to various disturbance regimes. In microcosms, we investigated the effect of sediment shifting on the colonization dynamics of 3 ciliate morphotypes differing in morphology, behavior and feeding strategy. The dynamics of the ciliate morphotypes inhabiting sediment pore water and overlying water were observed at 3 sediment shifting frequencies: (1) stable sediments, (2) periodically shifting sediments such as migrating ripples, and (3) continuously shifting sediments as occurring during scour events of the uppermost sediment. Sediment shifting significantly affected the abundance and growth rate of the ciliate morphotypes. The free-swimming filter feeder Dexiostoma campylum was vulnerable to washout by sediment shifting since significantly higher numbers occurred in the overlying water than in pore water. Abundance of D. campylum only increased in pore water of stable sediments. On the contrary, the vagile grasper feeder Chilodonella uncinata and the sessile filter feeder Vorticella convallaria had positive growth rates and successfully colonized sediments that shifted periodically and continuously. Thus, the spatio-temporal pattern of sediment dynamics acts as an essential factor of impact on the structure, distribution and function of ciliate communities in sand-bed streams.

  2. Water Infiltration and Hydraulic Conductivity in Sandy Cambisols

    DEFF Research Database (Denmark)

    Bens, Oliver; Wahl, Niels Arne; Fischer, Holger

    2006-01-01

    Soil hydrological properties like infiltration capacity and hydraulic conductivity have important consequences for hydrological properties of soils in river catchments and for flood risk prevention. They are dynamic properties due to varying land use management practices. The objective of this st......Soil hydrological properties like infiltration capacity and hydraulic conductivity have important consequences for hydrological properties of soils in river catchments and for flood risk prevention. They are dynamic properties due to varying land use management practices. The objective...... of this study was to characterize the variation of infiltration capacity, hydraulic conductivity and soil organoprofile development on forest sites with comparable geological substrate, soil type and climatic conditions, but different stand ages and tree species in terms of the effects of forest transformation...... from pure Scots pine stands towards pure European beech stands. The water infiltration capacity and hydraulic conductivity (K) of the investigated sandy-textured soils are low and very few macropores exist. Additionally these pores are marked by poor connectivity and therefore do not have any...

  3. Phosphorus fractions in sandy soils of vineyards in southern Brazil

    Directory of Open Access Journals (Sweden)

    Djalma Eugênio Schmitt

    2013-04-01

    Full Text Available Phosphorus (P applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm were collected from a native grassland area and two vineyards, after 14 years (vineyard 1 and 30 years (vineyard 2 of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.

  4. Evaluation of the Intel Sandy Bridge-EP server processor

    CERN Document Server

    Jarp, S; Leduc, J; Nowak, A; CERN. Geneva. IT Department

    2012-01-01

    In this paper we report on a set of benchmark results recently obtained by CERN openlab when comparing an 8-core “Sandy Bridge-EP” processor with Intel’s previous microarchitecture, the “Westmere-EP”. The Intel marketing names for these processors are “Xeon E5-2600 processor series” and “Xeon 5600 processor series”, respectively. Both processors are produced in a 32nm process, and both platforms are dual-socket servers. Multiple benchmarks were used to get a good understanding of the performance of the new processor. We used both industry-standard benchmarks, such as SPEC2006, and specific High Energy Physics benchmarks, representing both simulation of physics detectors and data analysis of physics events. Before summarizing the results we must stress the fact that benchmarking of modern processors is a very complex affair. One has to control (at least) the following features: processor frequency, overclocking via Turbo mode, the number of physical cores in use, the use of logical cores ...

  5. Extraction of sandy bedforms features through geodesic morphometry

    Science.gov (United States)

    Debese, Nathalie; Jacq, Jean-José; Garlan, Thierry

    2016-09-01

    State-of-art echosounders reveal fine-scale details of mobile sandy bedforms, which are commonly found on continental shelfs. At present, their dynamics are still far from being completely understood. These bedforms are a serious threat to navigation security, anthropic structures and activities, placing emphasis on research breakthroughs. Bedform geometries and their dynamics are closely linked; therefore, one approach is to develop semi-automatic tools aiming at extracting their structural features from bathymetric datasets. Current approaches mimic manual processes or rely on morphological simplification of bedforms. The 1D and 2D approaches cannot address the wide ranges of both types and complexities of bedforms. In contrast, this work attempts to follow a 3D global semi-automatic approach based on a bathymetric TIN. The currently extracted primitives are the salient ridge and valley lines of the sand structures, i.e., waves and mega-ripples. The main difficulty is eliminating the ripples that are found to heavily overprint any observations. To this end, an anisotropic filter that is able to discard these structures while still enhancing the wave ridges is proposed. The second part of the work addresses the semi-automatic interactive extraction and 3D augmented display of the main lines structures. The proposed protocol also allows geoscientists to interactively insert topological constraints.

  6. Simulations and Visualizations of Hurricane Sandy (2012) as Revealed by the NASA CAMVis

    Science.gov (United States)

    Shen, Bo-Wen

    2013-01-01

    Storm Sandy first appeared as a tropical storm in the southern Caribbean Sea on Oct. 22, 2012, moved northeastward, turned northwestward, and made landfall near Brigantine, New Jersey in late October. Sandy devastated surrounding areas, caused an estimated damage of $50 billion, and became the second costliest tropical cyclone (TC) in U.S. History surpassed only by Hurricane Katrina (2005). To save lives and mitigate economic damage, a central question to be addressed is to what extent the lead time of severe storm prediction such as Sandy can be extended (e.g., Emanuel 2012; Kerr 2012). In this study, we present 10 numerical experiments initialized at 00 and 1200 UTC Oct. 22-26, 2012, with the NASA coupled advanced global modeling and visualization systems (CAMVis). All of the predictions realistically capture Sandy's movement with the northwestward turn prior to its landfall. However, three experiments (initialized at 0000 UTC Oct. 22 and 24 and 1200 UTC Oct. 22) produce larger errors. Among the 10 experiments, the control run initialized at 0000 UTC Oct. 23 produces a remarkable 7-day forecast. To illustrate the impact of environmental flows on the predictability of Sandy, we produce and discuss four-dimensional (4-D) visualizations with the control run. 4-D visualizations clearly demonstrate the following multiscale processes that led to the sinuous track of Sandy: the initial steering impact of an upper-level trough (appearing over the northwestern Caribbean Sea and Gulf of Mexico), the blocking impact of systems to the northeast of Sandy, and the binary interaction with a mid-latitude, upper-level trough that appeared at 130degrees west longitude on Oct. 23, moved to the East Coast and intensified during the period of Oct. 29-30 prior to Sandy's landfall.

  7. Influence of advective bio-irrigation on carbon and nitrogen cycling in sandy sediments

    OpenAIRE

    Na, T.; Gribsholt, B.; Galaktionov, O. S.; T. Lee; Meysman, F. J. R.

    2008-01-01

    In sandy sediments, the burrow ventilation activity of benthic macrofauna can generate substantial advective flows within the sediment surrounding their burrows. Here we investigated the effects of such advective bio-irrigation on carbon and nitrogen cycling in sandy sediments. To this end, we combined a range of complementary experimental and modelling approaches in a microcosm study of the lugworm Arenicola marina (Polychaeta: Annelida). Bio-irrigation rates were determined using uranine as...

  8. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    OpenAIRE

    Siew Cheng Lee; Roslan Hashim; Shervin Motamedi; Ki-Il Song

    2014-01-01

    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However...

  9. Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet

    Science.gov (United States)

    2016-06-21

    Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet Christopher Martens Dept. of Marine Sciences CB...TITLE AND SUBTITLE Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet 5a. CONTRACT NUMBER 5b. GRANT...was noted that there was substantially higher organic material in the shallow troughs of the sand ripples than on the crests. Most of this appears

  10. 33 CFR 165.130 - Sandy Hook Bay, New Jersey-security zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sandy Hook Bay, New Jersey... Specific Regulated Navigation Areas and Limited Access Areas First Coast Guard District § 165.130 Sandy... following boundaries are a security zone: A line beginning on the shore at 40°25′55.6″ N, 074°04′31.4″ W...

  11. Nonfatal injuries 1 week after hurricane sandy--New York city metropolitan area, October 2012.

    Science.gov (United States)

    Brackbill, Robert M; Caramanica, Kimberly; Maliniak, Maret; Stellman, Steven D; Fairclough, Monique A; Farfel, Mark R; Turner, Lennon; Maslow, Carey B; Moy, Amanda J; Wu, David; Yu, Shengchao; Welch, Alice E; Cone, James E; Walker, Deborah J

    2014-10-24

    On October 29, 2012, Hurricane Sandy (Sandy) made landfall in densely populated areas of New York, New Jersey, and Connecticut. Flooding affected 51 square miles (132 square kilometers) of New York City (NYC) and resulted in 43 deaths, many caused by drowning in the home, along with numerous storm-related injuries. Thousands of those affected were survivors of the World Trade Center (WTC) disaster of September 11, 2001 (9/11) who had previously enrolled in the WTC Health Registry (Registry) cohort study. To assess Sandy-related injuries and associated risk factors among those who lived in Hurricane Sandy-flooded areas and elsewhere, the NYC Department of Health and Mental Hygiene surveyed 8,870 WTC survivors, who had provided physical and mental health updates 8 to 16 months before Sandy. Approximately 10% of the respondents in flooded areas reported injuries in the first week after Sandy; nearly 75% of those had more than one injury. Injuries occurred during evacuation and clean-up/repair of damaged or destroyed homes. Hurricane preparation and precautionary messages emphasizing potential for injury hazards during both evacuation and clean-up or repair of damaged residences might help mitigate the occurrence and severity of injury after a hurricane.

  12. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

    Directory of Open Access Journals (Sweden)

    M. Kunz

    2013-10-01

    Full Text Available At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  13. Hurricane Sandy Exposure and the Mental Health of World Trade Center Responders.

    Science.gov (United States)

    Bromet, Evelyn J; Clouston, Sean; Gonzalez, Adam; Kotov, Roman; Guerrera, Kathryn M; Luft, Benjamin J

    2017-04-03

    The psychological consequences of a second disaster on populations exposed to an earlier disaster have rarely been studied prospectively. Using a pre- and postdesign, we examined the effects of Hurricane Sandy on possible World Trade Center (WTC) related posttraumatic stress disorder (PTSD Checklist score of ≥ 50) and overall depression (major depressive disorder [MDD]; Patient Health Questionnaire depression score of ≥ 10) among 870 WTC responders with a follow-up monitoring visit at the Long Island WTC Health Program during the 6 months post-Hurricane Sandy. The Hurricane Sandy exposures evaluated were damage to home (8.3%) and to possessions (7.8%), gasoline shortage (24.1%), prolonged power outage (42.7%), and filing a Federal Emergency Management Agency claim (11.3%). A composite exposure score also was constructed. In unadjusted analyses, Hurricane Sandy exposures were associated with 1.77 to 5.38 increased likelihood of PTSD and 1.58 to 4.13 likelihood of MDD; odds ratios for ≥ 3 exposures were 6.47 for PTSD and 6.45 for MDD. After adjusting for demographic characteristics, WTC exposure, pre-Hurricane Sandy mental health status, and time between assessments, reporting ≥ 3 Hurricane Sandy exposures was associated with a 3.29 and 3.71 increased likelihood of PTSD and MDD, respectively. These findings underscore the importance of assessing the impact of a subsequent disaster in ongoing responder health surveillance programs.

  14. Evaluation of power outages in Connecticut during hypothetical future Hurricane Sandy scenarios

    Science.gov (United States)

    Wanik, D. W.; Anagnostou, E. N.; Astitha, M.; Frediani, M. E.; Yang, J.

    2015-12-01

    Reliable electric power is a staple of our modern society.The purpose of this work was to evaluate the occurrence of power outages under more intense, future Hurricane Sandy simulations in Connecticut. In addition, we also evaluated how many crews would be necessary to restore power in 7 days, and how different vegetation scenarios might contribute to a decrease in outages. We trained five pairwise models on each current Sandy runs (2012) as training using the random forest model (each validated using 10-fold cross-validation), and used each future Sandy run as an independent test. We predict that a future Sandy would have 2.5x as many outages as current Sandy, which would require 3.23x as many crews as current Sandy to restore power in 7 days. We also found that increased vegetation management might decrease outages, which has implications for both fair-weather and storm days of all types (i.e. blizzards, thunderstorms, ice storms). Although we have only evaluated outages for electric distribution networks, there are many other types (water supply, wastewater, telecommunications) that would likely benefit from an analysis of this type. In addition, given that we have the weather simulations already processed within our 2-km weather simulation domain, we would like to expand our vulnerability analyses to surrounding utilities in New Jersey, New York, Rhode Island, Massachusetts and New Hampshire to facilitate regional coordination among electric distribution networks.

  15. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

    Science.gov (United States)

    Kunz, M.; Mühr, B.; Kunz-Plapp, T.; Daniell, J. E.; Khazai, B.; Wenzel, F.; Vannieuwenhuyse, M.; Comes, T.; Elmer, F.; Schröter, K.; Fohringer, J.; Münzberg, T.; Lucas, C.; Zschau, J.

    2013-10-01

    At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation) and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  16. Hurricane Sandy (New Jersey): Mortality Rates in the Following Month and Quarter.

    Science.gov (United States)

    Kim, Soyeon; Kulkarni, Prathit A; Rajan, Mangala; Thomas, Pauline; Tsai, Stella; Tan, Christina; Davidow, Amy

    2017-08-01

    To describe changes in mortality after Hurricane Sandy made landfall in New Jersey on October 29, 2012. We used electronic death records to describe changes in all-cause and cause-specific mortality overall, in persons aged 76 years or older, and by 3 Sandy impact levels for the month and quarter following Hurricane Sandy compared with the same periods in earlier years adjusted for trends. All-cause mortality increased 6% (95% confidence interval [CI] = 2%, 11%) for the month, 5%, 8%, and 12% by increasing Sandy impact level; and 7% (95% CI = 5%, 10%) for the quarter, 5%, 8%, and 15% by increasing Sandy impact level. In elderly persons, all-cause mortality rates increased 10% (95% CI = 5%, 15%) and 13% (95% CI = 10%, 16%) in the month and quarter, respectively. Deaths that were cardiovascular disease-related increased by 6% in both periods, noninfectious respiratory disease-related by 24% in the quarter, infection-related by 20% in the quarter, and unintentional injury-related by 23% in the month. Mortality increased, heterogeneous by cause, for both periods after Hurricane Sandy, particularly in communities more severely affected and in the elderly, who may benefit from supportive services.

  17. Study of spatial distribution of sandy desertification in North China in recent 10 years

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; WU Wei; XUE Xian; SUN Qingwei; CHEN Guangting

    2004-01-01

    Sandy desertification is a land degradation characterized by wind erosion, mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in North China. It is one of main kinds of desertification/land degradation as well as water-soil erosion and salinization in China. Rapid and continuous spread of sandy desertification during last 50 years has created a major environmental and socio-economic problem in North China. Remote sensing monitored results in 2000 showed that the sandy desertified land area has been 38.57×104 km2. The area of potential to slightly sandy desertified land is 13.93×104 km2, moderately land 9.977×104 km2, severely land 7.909×104 km2 and very severely land 6.756×104km2. Sandy desertification mainly occurs in the semi-arid mixed farming-grazing zone and its northern rangeland zone, semi-arid dryland rainfed cropping zone and arid oasis-desert margin zone. The average annually developmental rate of sandy desertified land increased from 2,100tion in North China is "overall deterioration, while local rehabilitation". Already achieved rehabilitation results and monitoring assessment show that about 60% of desertified land in North China can be restored under the conditions of rational land-use ways and intensity.

  18. IMPROVEMENT OF SANDY SOIL WITH WATER-CONSERVING MEMBRANE AND ITS EFFECT ON CROP GROWTH

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-jun; CUI Xiang-hao; LI Qu-sheng

    2005-01-01

    Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and Ph of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary,promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.

  19. Effects of biochar and alkaline amendments on cadmium immobilization, selected nutrient and cadmium concentrations of lettuce (Lactuca sativa) in two contrasting soils

    DEFF Research Database (Denmark)

    Woldetsadik, Desta; Drechsel, Pay; Keraita, Bernard

    2016-01-01

    To assess the efficiency of seven treatments including biochars produced from dried faecal matter and manures as stabilizing agents of cadmium (Cd)-spiked soils, lettuce was grown in glasshouse on two contrasting soils. The soils used were moderately fertile silty loam and less fertile sandy loam....... Ammonium nitrate extraction results indicated that faecal matter biochar, cow manure biochar and lime significantly reduced bioavailable Cd by 84-87, 65-68 and 82-91 %, respectively, as compared to the spiked controls. Unpredictably, coffee husk biochar induced significant increment of Cd in NH4NO3...... extracts. The immobilization potential of faecal matter biochar and lime were superior than the other treatments. However, lime and egg shell promoted statistically lower yield and P, K and Zn concentrations response of lettuce plants compared to the biochar treatments. The lowest Cd and highest P tissue...

  20. Predicting Soil Moisture in the Field from Amplitude Temperature

    Science.gov (United States)

    Al-Kayssi, A. W.

    2009-04-01

    Measurements of amplitude temperature and soil moisture content of sandy loam and silty clay loam soils were conducted in Al-Mada'in Research Station south of Baghdad during the period from the 1st of February to the 30th of April, 2004. Exponential regression relations were developed between amplitude temperature and volumetric moisture content for soil depths of 0.5, 3.0, 7.5 and 15cm below surface, which was highly significant (R2>0.96). A good linear regression between measured and predicted soil moisture contents was deduced for each depth (r>0.97). Soil moisture content was successfully predicted from the regression line when amplitude temperature was known.

  1. Assessing the relative role of climate change and human activities in sandy desertification of Ordos region, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches. A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China. Potential NPP and the difference between potential and actual NPP were selected as indicators to assess the relative role of climate change and human activities in sandy desertification, respectively. Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000. The results showed that although some local places experienced an expansion of sandy desertification, the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend. The relative role of climate change and human activities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes. In the reversion of sandy desertification, climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate deciduous scrubs in north east of Ordos region; however, human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region. In the expansion of sandy desertification, human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around common boundary of Hanggin, Dalad Banners and Dongsheng City; however, climate change dominated the expansion of sandy desertification from 1991 to 2000, the expanded areas equably

  2. Degradation Characteristics of Saturated Marine Silty Sand Under Longi term Cyclic Loading%长期循环荷载作用下海洋饱和粉砂的弱化特性

    Institute of Scientific and Technical Information of China (English)

    李帅; 黄茂松

    2011-01-01

    为了研究海洋饱和粉砂在长期循环荷载作用下的弱化特性,对原状饱和粉砂进行了一系列不同固结条件下不排水单调和循环加载三轴试验,并在循环加载过程中通过弯曲元测试土体剪切波速.主要分析固结方式、动应力比以及循环次数对饱和砂土循环弱化特性的影响.试验结果表明,在相同的固结条件下,随循环次数的增加和动应力比的提高,土体的强度和刚度衰减显著,在相同的动应力比作用下,偏压固结相对于等压固结减缓了土体的循环弱化.利用动偏应力水平对海洋饱和粉砂循环荷载作用下强度和刚度的弱化特性进行了描述.%In order to study the long term cycltc degradation characteristics of saturated marine silty sand, a series of monotonic and cyclic undrained triaxial tests were conducted on isotropically and anisotropically consolidated natural undisturbed saturated silty sand with the shear wave measured by bender element system during cyclic loading. The influences of consolidation mode, cyclic stress ratio and cyclic number on the reduction of stiffness and strength of saturated sand were mainly analyzed. The experimental results show that under the same consolidated condition the undrained strength and stiffness of saturated sand markedly reduce with the increase of the cyclic stress ratio and the progressive number of cycles. On the other hand, anisotropic consolidation decelerates the degradation of stiffness under the same cyclic stress ratio. The dynamic deviatoric stress level is used to describe the reduction of stiffness and strength of saturated marine silty sand under cyclic loading.

  3. 安哥拉本哥拉市膨胀性粉质粘土浸水试验研究%Field Water Immersion Test on Expansive Silty Clay in Benguela, Angola

    Institute of Scientific and Technical Information of China (English)

    廖燕宏; 唐国艺; 刘争宏

    2013-01-01

    The alluvial or diluvial silty clay around Benguela GRASA in Angola has the properties of swelling.Because of the very low water content,it is too dry to fetch the undisturbed sample,but the laboratory index from disturbed samples such as free swell and atterberg limits may distort the real fact~ So it is necessary and helpful to adopt field water immersion test for ascertaining the swelling properties.The results of the field test indicated that the laboratory results have limitations and mistakes to determine the swelling properties; the silty clay has a high potential of swelling because of low water content; while increasing the water content,the soil has high swelling deformation and expansive force; the deformation curve of the plate shows subsoil heave is sensitive with small fluctuation of moisture content; but,the strength would fall fast if the water content increase more,the Benguela silty clay has obvious sensitivity to water with the phenomena swelling and weakness during water content increasing.%本哥拉GRASA地区山前冲洪积成因的膨胀性粉质粘土因其含水率很小,难于取得原状土样,通过自由膨胀率、界限含水率等室内试验指标评价为非膨胀性土.但是现场浸水载荷试验结果表明:室内试验结果具有很大的局限性且存在误判的可能;本哥拉粉质粘土常年处于干燥低含水率状态,具有很大的膨胀潜势,浸水饱和后的膨胀量和膨胀力均很强烈;载荷板的变形过程揭示了土体遇水明显膨胀又容易发生地基破坏的性质,承载力在接近或达到饱和后,其强度又迅速大幅降低,粉质粘土具有明显遇水膨胀和增湿软化强烈的水敏特性.本哥拉粉质粘土的室内试验和现场试验具有显著的差异性,现场浸水载荷试验对于正确判定该类膨胀土的工程性质具有不可替代的作用.

  4. Tsunami characteristics and formation potential of sandy tsunami deposit in Sanriku Coast: implications from numerical modeling

    Science.gov (United States)

    Sugawara, D.; Haraguchi, T.; Takahashi, T.

    2013-12-01

    Geological investigation of paleotsunami deposit is crucial for knowing the history and magnitude of tsunami events in the past. Among various kinds of grain sizes, sandy tsunami deposit has been best investigated by previous studies, because of its potential for identification in the sedimentary column. Many sandy tsunami deposits have been found from coastal plains, which have sandy beach and low-lying wetlands. However, sandy tsunami deposits in narrow valleys at rocky ria coast have rarely been found. It may be presumed that formation potential of sandy tsunami layer in the rocky coasts is generally lower than coastal plains, because of the absence of sandy beach, tsunami run-up on steeper slope and stronger return flow. In this presentation, characteristics of the 2011 Tohoku-oki earthquake tsunami in Sanriku Coast, a continuous rocky ria coast located in the northeast Japan, is investigated based on numerical modeling. In addition, the formation potential of sandy tsunami deposit is also investigated based on numerical modeling of sediment transport. Preliminary result of tsunami hydrodynamics showed that the waveform and amplification of the tsunami are clearly affected by the local bathymetry, which is associated with submerged topography formed during the last glacial stage. Although the tsunami height in the offshore of each bay is around 8.0 m, the tsunami height at the bay head was increased in different way. The amplification factor at the bay head was typically 2.0 among most of V-shaped narrow embayments; meanwhile the amplification factor is much lower than 1.0 at some cases. The preliminary result of the modeling of sediment transport predicted huge amount of sediments may be suspended into the water column, given that sandy deposit is available there. Massive erosion and deposition of sea bottom sediments may commonly take place in the bays. However, formation of onshore tsunami deposit differs from each other. Whether the suspended sediments

  5. Diesel and silica monitoring at two sites following hurricane sandy.

    Science.gov (United States)

    Freund, Alice; Zuckerman, Norman; Luo, Honghong; Hsu, Hsiao-Hsien; Lucchini, Roberto

    2014-01-01

    Following Hurricane Sandy, which hit New York City and New Jersey in October 2012, industrial hygienists from the Mount Sinai and Belleview/New York University occupational medicine clinics conducted monitoring for diesel exhaust and silica in lower Manhattan and Rockaway Peninsula. Average daytime elemental carbon levels at three stations in lower Manhattan on December 4, 2012, ranged from 9 to18 μg/m(3). Sub-micron particle counts at various times on the same day were over 200,000 particles per cubic centimeter on many streets in lower Manhattan. In Rockaway Peninsula on December 12, 2012, all average daytime elemental carbon levels were below a detection limit of approximately 7 μg/m(3). The average daytime crystalline silica dust concentration was below detection at two sites on Rockaway Peninsula, and was 0.015 mg/m(3) quartz where sand was being replaced on the beach. The daily average levels of elemental carbon and airborne particulates that we measured are in the range of levels that have been found to cause respiratory effects in sensitive subpopulations like asthmatic patients after 2 hr of exposure. Control of exposure to diesel exhaust must be considered following natural disasters where diesel-powered equipment is used in cleanup and recovery. Although peak silica exposures were not likely captured in this study, but were reported by a government agency to have exceeded recommended guidelines for at least one cleanup worker, we recommend further study of silica exposures when debris removal operations or traffic create visible levels of suspended dust from soil or sand.

  6. Release behavior of copper and zinc from sandy soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-kui; XIA Yi-ping

    2005-01-01

    The concentrations and chemical forms of copper(Gu) and zinc(Zn) in surface soils directly influence the movement of Gu and Zn. In this study, thirteen sandy soil samples with a wide range of total Cu and Zn concentrations were collected for evaluating the relationships between Cu and Zn release and extraction time, ratio of soil to water, pH and electrolyte types. The results indicated that Cu released in batch extraction that represents long-term leaching was mainly from exchangeable, and carbonate bound Cu fractions, and Zn released in the batch extraction was mainly from its carbonate bound fraction. However, the Cu and Zn leached from the soils using the column leaching that represents short-term leaching were mainly from their exchangeable fractions. Soil column leaching at different pH values indicated that the amounts of leached Zn and Cu were greatly affected by pH. The Cu and Zn release experiments with varying extraction times and ratio of soil to water suggest that long-term water-logging in the soils after rain may increase contact time of the soils with water and the release of Cu and Zn to water from the soils, and total amounts of Cu or Zn released from the soils increase, but the Cu or Zn concentration in the surface runoff decrease with increasing rainfall intensity. The increased Ca concentration in soil solution increased stability of organic matter-mineral complexes and might decrease the dissolution of organic matter, and thus decreased the release of Cu-binding component of organic matter. However, high concentration of Na in the soil solution increased the dispersion of the organic matter-mineral complexes and increased dissolution of organic matter and the release of Cu from the soils.

  7. Biodegradation and bioremediation potential of diazinon-degrading Serratia marcescens to remove other organophosphorus pesticides from soils.

    Science.gov (United States)

    Cycoń, Mariusz; Żmijowska, Agnieszka; Wójcik, Marcin; Piotrowska-Seget, Zofia

    2013-03-15

    The ability of diazinon-degrading Serratia marcescens to remove organophosphorus pesticides (OPPs), i.e. chlorpyrifos (CP), fenitrothion (FT), and parathion (PT) was studied in a mineral salt medium (MSM) and in three soils of different characteristics. This strain was capable of using all insecticides at concentration of 50 mg/l as the only carbon source when grown in MSM, and 58.9%, 70.5%, and 82.5% of the initial dosage of CP, FT, and PT, respectively was degraded within 14 days. The biodegradation experiment showed that autochthonous microflora in all soils was characterized by a degradation potential of all tested OPPs; however, the initial lag phases for degradation of CP and FT, especially in sandy soil, were observed. During the 42-day experiment, 45.3%, 61.4% and 72.5% of the initial dose of CP, FT, and PT, respectively, was removed in sandy soil whereas the degradation of CP, FT, and PT in the same period, in sandy loam and silty soils reached 61.4%, 79.7% and 64.2%, and 68.9%, 81.0% and 63.6%, respectively. S. marcescens introduced into sterile soils showed a higher degradation potential (5-13%) for OPPs removal than those observed in non-sterile soil with naturally occurring attenuation. Inoculation of non-sterile soils with S. marcescens enhanced the disappearance rates of all insecticides, and DT50 for CP, FT, and PT was reduced by 20.7, 11.3 and 13.0 days, and 11.9, 7.0 and 8.1 days, and 9.7, 14.5 and 12.6 days in sandy, sandy loam, and silty soils, respectively, in comparison with non-sterile soils with only indigenous microflora. This ability of S. marcescens makes it a suitable strain for bioremediation of soils contaminated with OPPs.

  8. Investigating the Effect of Soil Texture and Fertility on Evapotranspiration and Crop Coefficient of Maize Forage

    Directory of Open Access Journals (Sweden)

    M. Ghorbanian Kerdabadi

    2017-02-01

    Full Text Available Introduction: Crop coefficient varies in different environmental conditions, such as deficit irrigation, salinity and intercropping. The effect of soil fertility and texture of crop coefficient and evapotranspiration of maize was investigated in this study. Low soil fertility and food shortages as a stressful environment for plants that makes it different evapotranspiration rates of evapotranspiration calculation is based on the FAO publication 56. Razzaghi et al. (2012 investigate the effect of soil type and soil-drying during the seed-filling phase on N-uptake, yield and water use, a Danish-bred cultivar (CV. Titicaca was grown in field lysimeters with sand, sandy loam and sandy clay loam soil. Zhang et al (2014 were investigated the Effect of adding different amounts of nitrogen during three years (from 2010 to 2012 on water use efficiency and crop evapotranspiration two varieties of winter wheat. The results of their study showed. The results indicated the following: (1 in this dry land farming system, increased N fertilization could raise wheat yield, and the drought-tolerant Changhan No. 58 showed a yield advantage in drought environments with high N fertilizer rates; (2 N application affected water consumption in different soil layers, and promoted wheat absorbing deeper soil water and so increased utilization of soil water; and (3 comprehensive consideration of yield and WUE of wheat indicated that the N rate of 270 kg/ha for Changhan No. 58 was better to avoid the risk of reduced production reduction due to lack of precipitation; however, under conditions of better soil moisture, the N rate of 180 kg/ha was more economic. Materials and Methods: The study was a factorial experiment in a completely randomized design with three soil texture treatment, including silty clay loam, loam and sandy-loam soil and three fertility treatment, including without fertilizer, one and two percent fertilizer( It was conducted at the experimental farm in

  9. Genesis of Hurricane Sandy (2012) Simulated with a Global Mesoscale Model

    Science.gov (United States)

    Shen, Bo-Wen; DeMaria, Mark; Li, J.-L. F.; Cheung, S.

    2013-01-01

    In this study, we investigate the formation predictability of Hurricane Sandy (2012) with a global mesoscale model. We first present five track and intensity forecasts of Sandy initialized at 00Z 22-26 October 2012, realistically producing its movement with a northwestward turn prior to its landfall. We then show that three experiments initialized at 00Z 16-18 October captured the genesis of Sandy with a lead time of up to 6 days and simulated reasonable evolution of Sandy's track and intensity in the next 2 day period of 18Z 21-23 October. Results suggest that the extended lead time of formation prediction is achieved by realistic simulations of multiscale processes, including (1) the interaction between an easterly wave and a low-level westerly wind belt (WWB) and (2) the appearance of the upper-level trough at 200 hPa to Sandy's northwest. The low-level WWB and upper-level trough are likely associated with a Madden-Julian Oscillation.

  10. Degraded Ecosystem and its Rehabilitating Measures in Sandy Areas of North China

    Institute of Scientific and Technical Information of China (English)

    ZHANGFengchun; LUQi

    2004-01-01

    Ecosystem degradation occurs in parallel with desertification process in sandy areas of North China. The vast sandy areas in North China are characterized with flexible environments and fragile ecosystems as well as intensive human activities. Due to the annual precipitation gradient decreases from east to west in North China, the whole sandy region falls into 3 main climatic zones: add, semi-add and dry sub-humid zones.The ecosystems in each type of climatic zones are different in climatic conditions, human activities,cultural dimensions, vegetation covers, landscapes, and causes and processes of ecosystem degradation.Therefore, the most effective rehabilitation measures of degraded ecosystems in different types of the climatic zones are also different. For the arid sandy areas, vegetation rehabilitation of degraded ecosystems needs to be completely closed, assisting with artificial measures, such as plantation, irrigation or others. For semi-add sandy areas, the effective measures of vegetation rehabilitation of degraded ecosystems include increasing of proportion of forests and rangelands and limitation of reclamation; reducing the carrying capacity of livestock on unit area of rangelands and growth of fodder plants; and plantation on the lowlands betweens and dunes. For the dry sub-humid areas, the most effective measure is enclosure of degraded ecosystems combined with plantation, and in some cases, just stop uses by grazing or reclamation.

  11. Morphology of Rain Water Channeling in Systematically Varied Model Sandy Soils

    Science.gov (United States)

    Wei, Yuli; Cejas, Cesare M.; Barrois, Rémi; Dreyfus, Rémi; Durian, Douglas J.

    2014-10-01

    We visualize the formation of fingered flow in dry model sandy soils under different rain conditions using a quasi-2D experimental setup and systematically determine the impact of the soil grain diameter and surface wetting properties on the water channeling phenomenon. The model sandy soils we use are random closely packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates a shallow top layer of soil and creates a horizontal water wetting front that grows downward homogeneously until instabilities occur to form fingered flows. For hydrophobic sandy soils, in contrast, we observe that rain water ponds on the top of the soil surface until the hydraulic pressure is strong enough to overcome the capillary repellency of soil and create narrow water channels that penetrate the soil packing. Varying the raindrop impinging speed has little influence on water channel formation. However, varying the rain rate causes significant changes in the water infiltration depth, water channel width, and water channel separation. At a fixed rain condition, we combine the effects of the grain diameter and surface hydrophobicity into a single parameter and determine its influence on the water infiltration depth, water channel width, and water channel separation. We also demonstrate the efficiency of several soil water improvement methods that relate to the rain water channeling phenomenon, including prewetting sandy soils at different levels before rainfall, modifying soil surface flatness, and applying superabsorbent hydrogel particles as soil modifiers.

  12. The impact of Hurricane Sandy on the mental health of New York area residents.

    Science.gov (United States)

    Schwartz, Rebecca M; Sison, Cristina; Kerath, Samantha M; Murphy, Lisa; Breil, Trista; Sikavi, Daniel; Taioli, Emanuela

    2015-01-01

    To evaluate the long-term psychological impact of Hurricane Sandy on New York residents. Prospective, cross-sectional study. Community-based study. From October 2013 to February 2015, 669 adults in Long Island, Queens, and Staten Island completed a survey on their behavioral and psychological health, demographics, and hurricane impact (ie, exposure). Depression, anxiety, and post-traumatic stress disorder (PTSD). Using multivariable logistic regression models, the relationships between Hurricane Sandy exposure and depression, anxiety, and PTSD were examined. Participants experienced an average of 3.9 exposures to Hurricane Sandy, most of which were related to property damage/loss. Probable depression was reported in 33.4 percent of participants, probable anxiety in 46 percent, and probable PTSD in 21.1 percent. Increased exposure to Hurricane Sandy was significantly associated with a greater likelihood of depression (odds ratio [OR] = 1.09, 95% confidence interval [CI]: 1.04-1.14), anxiety (OR = 1.08, 95% CI: 1.03-1.13), and probable PTSD (OR = 1.32, 95% CI: 1.23-1.40), even after controlling for demographic factors known to increase susceptibility to mental health issues. Individuals affected by Hurricane Sandy reported high levels of mental health issues and were at an increased risk of depression, anxiety, and PTSD in the years following the storm. Recovery and prevention efforts should focus on mental health issues in affected populations.

  13. Effect of soil texture on phytoremediation of arsenic-contaminated soils

    Science.gov (United States)

    Pallud, C. E.; Matzen, S. L.; Olson, A.

    2015-12-01

    Soil arsenic (As) contamination is a global problem, resulting in part from anthropogenic activities, including the use of arsenical pesticides and treated wood, mining, and irrigated agriculture. Phytoextraction using the hyperaccumulating fern Pteris vittata is a promising new technology to remediate soils with shallow arsenic contamination with minimal site disturbance. However, many challenges still lie ahead for a global application of phytoremediation. For example, remediation times using P. vittata are on the order of decades. In addition, most research on As phytoextraction with P. vittata has examined As removal from sandy soils, where As is more available, with little research focusing on As removal from clayey soils, where As is less available. The objective of this study is to determine the effects of soil texture and soil fertilization on As extraction by P. vittata, to optimize remediation efficiency and decrease remediation time under complex field conditions. A field study was established 2.5 years ago in an abandoned railroad grade contaminated with As (average 85.5 mg kg-1) with texture varying from sandy loam to silty clay loam. Organic N, inorganic N, organic P, inorganic P, and compost were applied to separate sub-plots; control ferns were grown in untreated soil. In a parallel greenhouse experiment, ferns were grown in sandy loam soil extracted from the field (180 mg As kg-1), with similar treatments as those used at the field site, plus a high phosphate treatment and treatments with arbuscular mycorrhizal fungi. In the field study, fern mortality was 24% higher in clayey soil than in sandy soil due to waterlogging, while As was primarily associated with sandy soil. Results from the sandy loam soil indicate that soil treatments did not significantly increase As phytoextraction, which was lower in phosphate-treated ferns than in control ferns, both in the field and greenhouse study. Under greenhouse conditions, ferns treated with organic N were

  14. 有机氯代烃在壤土中的吸附和解吸特性%Sorption and Desorption of Chlorinated Hydrocarbons onto Loam Soil

    Institute of Scientific and Technical Information of China (English)

    张凤君; 贾晗; 刘佳露; 董佳新; 卢伟; 吕聪

    2015-01-01

    The sorption and desorption characteristics of the four organic chlorinated hydrocarbons (trichloroethylene (TCE) ,cis 1 ,2 dichloroethylene (cis 1 ,2 DCE) ,1 ,1 ,1 trichloroethane (1 ,1 , 1 TCA ) , and 1 ,2 dichloroethane (1 ,2 DCA )) onto loam soil are investigated by a batch of experiments in this study .The results indicate that the sorption equilibrium time of the four chlorinated hydrocarbons onto the loam soil is about three days .The sorption isotherm for all compounds is nearly linear , and fits to Freundlich isotherm slightly over the entire concentration range . As for chloroethylenes ,TCE is strongly sorbed to the loam samples (Kd = 0 .624 L/kg) ,and followed by cis‐DCE (Kd = 0 .238 L/kg) .For chloroethanes ,1 ,1 ,1 TCA is strongly sorbed (Kd = 0 .520 L/kg) ,and followed by 1 ,2 DCA (Kd = 0 .353 L/kg) .This is consistent with the order of hydrophobicity of the compounds .In addition , the lg Koc value is estimated by Abdul , Dobbs , Rao and Cong empirical regression formula respectively in this study , and the results show that the estimated lg Koc value determined by Abdul regression is significantly lower than the calculated value ,and the estimated lgKoc value determined by Cong regression is significantly higher than the calculated value , while the estimated lg Koc values determined by Dobbs and Rao regression are much closer to the calculated values . This demonstrates that the Dobbs and Rao regression is more suitable for lg Koc estimation for chlorinated hydrocarbons .Besides ,it is found that there is a certain lag in desorption of chlorinated hydrocarbons from the loam soil ;and the higher the sorption capacity of chlorinated hydrocarbon ,the lower the desorption capacity of chlorinated hydrocarbon .%选取三氯乙烯(TCE)、顺1,2二氯乙烯(cis 1,2 DCE)、1,1,1三氯乙烷(1,1,1 TCA)、1,2二氯乙烷(1,2 DCA)4种常见的有机氯代烃,通过批次实验研究其在壤土中的吸附和

  15. Development of methods for multiresidue analysis of rice post-emergence herbicides in loam soil and their possible applications to soils of different composition.

    Science.gov (United States)

    Niell, Silvina; Pareja, Lucia; Asteggiante, Lucía Geis; Roehrs, Rafael; Pizzutti, Ionara R; García, Claudio; Heinzen, Horacio; Cesio, María Verónica

    2010-01-01

    Two simple and straightforward sample preparation methods were developed for the multiresidue analysis of post-emergence herbicides in loam soil that are commonly used in rice crop cultivation. A number of strategic soil extraction and cleanup methods were evaluated. The instrumental analysis was performed by HPLC with a diode array detector. The best compromise between the recoveries (69-98%) and good repeatability (RSD clomazone were analyzed simultaneously. Quinclorac and bispyribac sodium were also assayed, but their recoveries were below 50%. Both methods had an LOD of 0.7 microg/kg and could accurately determine the residues at the 2 microg/kg level. These two methods could not be applied directly to other soil types as the recoveries strongly depended on the soil composition. The developed methodologies were successfully applied in monitoring 87 real-world soil samples, in which only propanil (6 to 12 microg/kg) and clomazone (15 to 20 microg/kg) residues could be detected.

  16. How Unique was Hurricane Sandy? Sedimentary Reconstructions of Extreme Flooding from New York Harbor

    Science.gov (United States)

    Brandon, Christine M.; Woodruff, Jonathan D.; Donnelly, Jeffrey P.; Sullivan, Richard M.

    2014-12-01

    The magnitude of flooding in New York City by Hurricane Sandy is commonly believed to be extremely rare, with estimated return periods near or greater than 1000 years. However, the brevity of tide gauge records result in significant uncertainties when estimating the uniqueness of such an event. Here we compare resultant deposition by Hurricane Sandy to earlier storm-induced flood layers in order to extend records of flooding to the city beyond the instrumental dataset. Inversely modeled storm conditions from grain size trends show that a more compact yet more intense hurricane in 1821 CE probably resulted in a similar storm tide and a significantly larger storm surge. Our results indicate the occurrence of additional flood events like Hurricane Sandy in recent centuries, and highlight the inadequacies of the instrumental record in estimating current flood risk by such extreme events.

  17. Sandy desertification trend in western Northeast China Plain in the past 10 years

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid economic development, the deterioration of eco-environment has occurred and the desertification becomes very obvious. The first part of this paper studies the regional differences of landscape patterns and explores the regional differences of desertification. The second part aims to reveal the dynamics of desertification in the 1990s by using NOAA/AVHRR data and thematic data in GIS database. This work lays a scientific basis for the rehabilitation and development of the sandy lands.

  18. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.

    Science.gov (United States)

    Zhuang, Wenhua; Li, Longguo; Liu, Chao

    2013-01-01

    Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

  19. The North Atlantic Coast Comprehensive Study and the US Army Corps of Engineers Sandy Recovery Program

    Directory of Open Access Journals (Sweden)

    Henn Roselle

    2016-01-01

    Full Text Available The Disaster Relief Appropriation Act of 2013 (P.L. 113-2 recognized the need to comprehensively evaluate the existing and planned measures to reduce the flooding risk from tidally-influenced storm surges as well as other alternatives for areas at risk to future storm damages. The legislation directed the US Army Corps of Engineers to undertake a Comprehensive Study of the Sandy impacted areas in the North Atlantic Division (Maine to Virginia. This paper reviews the findings and outcomes of the NACCS and their application across the USACE’s Sandy Recovery Program.

  20. Vegetation landscape structure and dynamics in sandy forest-steppe ecotone

    Institute of Scientific and Technical Information of China (English)

    ZOUChun-jing; HANShi-jie; XUWen-duo; LIDao-tang

    2003-01-01

    Sandy forest-steppe ecotone in Baiyinaobao Natural Reserve of Inner Mongolia Autonomous Region of China is one of the special landscape types in forest-steppe vegetation zone in China. Vegetation landscape types, landscape patches and patch size were measured by the field investigation, forest photograph, and airscape. The structure of landscape patches in sandy forest-steppe ecotone, including composition structure, and size structure, was studied and the dynamics and transformation of landscape patches were analyzed. The data obtained in this study could provide theoretical basis for the research on vegetation landscape in forest-steppe ecotones and other vegetation types.

  1. Propagation of Rayleigh waves in anisotropic layer overlying a semi-infinite sandy medium

    Directory of Open Access Journals (Sweden)

    P.C. Pal

    2015-06-01

    Full Text Available The present investigation deals with the propagation of Rayleigh waves in anisotropic layer overlying a sandy medium. Anisotropic material is in the nature of most general case i.e. of triclinic crystal and sandy medium is of alluvial soil type. The solutions for layer and half-space are obtained analytically. The displacement components in x and z directions are obtained for both the media. The dispersion relation is obtained subjected to certain boundary conditions. The special cases are considered. The numerical results are presented in the form of wave number and phase velocity (k − c analytical curves.

  2. Draft Detailed Project Report and Environmental Assessment, Sandy Point Navigation Channel, Whatcom County, Washington.

    Science.gov (United States)

    1984-11-01

    ment. Maurice L. Schwartz, of Coastal Consultants, Inc., provided a report on shoaling at Sandy Point which was also used in developing this...8217 BS SOFT TO VERY A. SFT. LACO [...j L RAVEL C0%TACT SUR- TORVAYAE.BOOPSF FIT ORGANIC SILT £PEAT IN LAYE RS, VERY CT LL:RA BLACK * ~~ VE ASN PL 44...Schwartz, Maurice L. 1983. Marina inlet shoaling at Sandy Point, Washington. Submitted to Seattle District, U.S. Amy Corps of Engineers. U.S. Fish and

  3. Experiments on the movement of pesticides in sandy soils to groundwater : prospects of testing preferential transport models

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2012-01-01

    Many agricultural areas with humic-sandy and loamy-sandy soils are used also for the extraction of water for drinking-water supply. Model concepts have been developed for the fast preferential transport of plant protection products (pesticides) in such soils, e.g. by fingered and funneled flow. An i

  4. 78 FR 12109 - Order Extending Temporary Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy

    Science.gov (United States)

    2013-02-21

    ... seq. \\2\\ Order Granting Exemptions from Certain Rules of Regulation SHO Related to Hurricane Sandy... Hurricane Sandy made landfall and whose settlement depends on the delivery of such physical certificates (or... COMMISSION Order Extending Temporary Exemptions From Certain Rules of Regulation SHO Related to...

  5. Maize productivity and mineral N dynamics following different soil fertility management practices on a depleted sandy soil in Zimbabwe

    NARCIS (Netherlands)

    Chikowo, R.; Mapfumo, P.; Nyamugafata, P.; Giller, K.E.

    2004-01-01

    There is a need for an improved understanding of nitrogen (N) dynamics in depleted sandy soils in southern Africa. A field experiment was conducted to evaluate the performance of different soil fertility improvement practices on a degraded granitic sandy soil in Zimbabwe. Legumes capable of accumula

  6. 33 CFR 334.102 - Sandy Hook Bay, Naval Weapons Station EARLE, Piers and Terminal Channel, restricted area...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Sandy Hook Bay, Naval Weapons... DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.102 Sandy Hook Bay, Naval Weapons Station EARLE, Piers..., shall be enforced by the Commanding Officer, Naval Weapons Station Earle, and/or other persons or...

  7. Improved retention of imidacloprid (Confidor) in soils by adding vermicompost from spent grape marc.

    Science.gov (United States)

    Fernández-Bayo, Jesús D; Nogales, Rogelio; Romero, Esperanza

    2007-05-25

    Batch sorption experiments of the insecticide imidacloprid by ten widely different Spanish soils were carried out. The sorption was studied for the active ingredient and its registered formulation Confidor. The temperature effect was studied at 15 degrees C and 25 degrees C. The addition of a vermicompost from spent grape marc (natural and ground), containing 344 g kg(-1) organic carbon, on the sorption of imidacloprid by two selected soils, a sandy loam and a silty clay loam, having organic carbon content of 3.6 g kg(-1) and 9.3 g kg(-1), respectively, was evaluated. Prior to the addition of this vermicompost, desorption isotherms with both selected soils, were also performed. The apparent hysteresis index (AHI) parameter was used to quantify sorption-desorption hysteresis. Sorption coefficients, K(d) and K(f), for the active ingredient and Confidor(R) in the different soils were similar. Sorption decreased with increasing temperature, this fact has special interest in greenhouse systems. A significant correlation (R(2)=0.965; Pvermicompost was an effective sorbent of this insecticide (K(f)=149). The sorption of imidacloprid increased significantly in soils amended with this vermicompost. The most pronounced effect was found in the sandy loam soil with low OC content, where the addition of 5% and 10% of vermicompost increased K(f) values by 8- and 15-fold, respectively. Soil desorption of imidacloprid was slower for the soil with the higher OC and clay content.

  8. The effect of EDTA on Helianthus annuus uptake, selectivity, and translocation of heavy metals when grown in Ohio, New Mexico and Colombia soils.

    Science.gov (United States)

    Turgut, Cafer; Pepe, M Katie; Cutright, Teresa J

    2005-02-01

    The use of two EDTA concentrations for enhancing the bioavailability of cadmium, chromium, and nickel in three natural soils (Ohio, New Mexico and Colombia) was investigated. The resulting uptake, translocation and selectivity with Helianthus annuus after mobilization were also examined. In general, plants grown in the sandy-loam Ohio soil had a higher uptake that resulted in a selectivity and total metal content of Cd>Cr>Ni and 0.73 mg and Cr>Cd>Ni and 0.32 mg for 0.1 and 0.3 g kg-1 EDTA, respectively. With the silty-loam New Mexico soil, although the total metal uptake was not statistically different the EDTA level did alter the selectivity; Cd>Cr>Ni (0.1 g kg-1 EDTA) and Cd>Cr>Ni (0.3 g kg-1 EDTA). Conversely, with the Colombian (sandy clay loam) soil increasing the EDTA level resulted in a higher total metal uptake (0.62 mg) than the 0.1 g kg-1 (0.59 mg) treatment. For all three soils, the translocation of Cd was limited. Evaluating the mobile metal fraction with and without EDTA determined that the chelator was capable of overcoming mass transfer limitations associated with the expandable clay fraction in the soils. Root wash results and root biomass concentrations indicated that Cd sorption was occurring. Therefore limited Cd translocation was attributed to insufficient phytochelatin levels.

  9. Cultivos de cobertura: efectos sobre la macroporosidad y la estabilidad estructural de un suelo franco-limoso Cover crops: effects on soil macroporosity and soil structural stability in a silt loam soil

    Directory of Open Access Journals (Sweden)

    María Florencia Varela

    2011-07-01

    Full Text Available Los suelos franco-limosos manejados con siembra directa a menudo poseen porosidad estructural baja e inestable. Con el objetivo de determinar la capacidad de los cultivos de cobertura (CC de mejorar la porosidad y estabilidad estructural de estos suelos se llevaron a cabo experimentos de campo y de invernáculo. Ambos tuvieron tratamientos con y sin CC (avena, Avena sativa L., en rotación con soja (Glicine max L. Merr.. Luego de los CC se midieron densidad aparente (DA, el índice de inestabilidad estructural (IE y en el ensayo de invernáculo además, se midió la evolución de la distribución de tamaño de poros (DTP. En ambos ensayos la introducción de CC no disminuyó la DA, aunque incrementó la estabilidad del suelo (PNo- till (NT silt loam topsoils have often a low and unstable structural porosity. The objective of this study was to determine the capability of cover crops (CC of improving the structural porosity and stability of silt loam soils under NT. Greenhouse and field experiments were carried out on a silt loam soil (Typic Argiudoll with and without CC (oat, Avena sativa L. in crop sequences with soybean (Glicine max L. Merr.. Soil bulk density (DA and aggregate instability index (IE were measured after the CC in both experiments. In the greenhouse experiment, soil pore size distribution (DTP was measured. The use of CC did not change DA, but soil IE was significantly lower in crop sequences with CC (P < 0.05 both under field and greenhouse conditions. Stability increases were likely due to the effect of CC residues and root mass. No differences in DTP were found between treatments, although a significant effect of sampling date was observed (P<0.05. Changes in DTP were due to significant increases in mesopore (517.5% and macropore (52.7% volumes. Such changes occurred in all the treatments, probably due to the soil wetting-drying cycles. The results found in this study agree with other studies carried out on silt loams in the

  10. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...

  11. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    NARCIS (Netherlands)

    Cartaxana, P; Mendes, CR; van Leeuwe, MA; Brotas, [No Value

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on

  12. Lessons from Hurricane Sandy: a community response in Brooklyn, New York.

    Science.gov (United States)

    Schmeltz, Michael T; González, Sonia K; Fuentes, Liza; Kwan, Amy; Ortega-Williams, Anna; Cowan, Lisa Pilar

    2013-10-01

    The frequency and intensity of extreme weather events have increased in recent decades; one example is Hurricane Sandy. If the frequency and severity continue or increase, adaptation and mitigation efforts are needed to protect vulnerable populations and improve daily life under changed weather conditions. This field report examines the devastation due to Hurricane Sandy experienced in Red Hook, Brooklyn, New York, a neighborhood consisting of geographically isolated low-lying commercial and residential units, with a concentration of low-income housing, and disproportionate rates of poverty and poor health outcomes largely experienced by Black and Latino residents. Multiple sources of data were reviewed, including street canvasses, governmental reports, community flyers, and meeting transcripts, as well as firsthand observations by a local nonprofit Red Hook Initiative (RHI) and community members, and social media accounts of the effects of Sandy and the response to daily needs. These data are considered within existing theory, evidence, and practice on protecting public health during extreme weather events. Firsthand observations show that a community-based organization in Red Hook, RHI, was at the center of the response to disaster relief, despite the lack of staff training in response to events such as Hurricane Sandy. Review of these data underscores that adaptation and response to climate change and likely resultant extreme weather is a dynamic process requiring an official coordinated governmental response along with on-the-ground volunteer community responders.

  13. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  14. Weathering the Superstorm: From Texts to Twitter--How Campus Communicators Overcame Hurricane Sandy

    Science.gov (United States)

    Towns, Gail

    2013-01-01

    By the time Superstorm Sandy struck New Jersey in late October 2012, Kathy Corbalis, executive director of communications and college relations at Atlantic Cape Community College, and her team were battle-tested. In the 15 months before the hurricane, the college experienced two bomb threats via Twitter, a lockdown due to gunfire, an on-campus…

  15. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the ero

  16. 2012 USACE Post Sandy Topographic LiDAR: Virginia and Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert Project...

  17. Solute leaching in a sandy soil with a water-repellent surface layer: a simulation.

    NARCIS (Netherlands)

    Rooij, de G.H.; Vries, de P.

    1996-01-01

    Many sandy soils in the Netherlands have a water-repellent surface layer covering a wettable soil with a shallow groundwater table. Fingers form in the water-repellent surface layer and rapidly transport water and solutes to the wettable soil in which the streamlines diverge. Although several field

  18. Modeling the growth and migration of sandy shoals on ebb-tidal deltas

    NARCIS (Netherlands)

    Ridderinkhof, W.; de Swart, H. E.; van der Vegt, M.; Hoekstra, P.

    2016-01-01

    Coherent sandy shoals that migrate toward the downdrift coast are observed on many ebb-tidal deltas. In this study, processes that cause the growth and migration of shoals on ebb-tidal deltas are identified. Moreover, the effect of the incident wave energy and the tidal prism of an inlet on the migr

  19. Trends in soil organic matter contents in Dutch grasslands and maize fields on sandy soils

    NARCIS (Netherlands)

    Hanegraaf, M.C.; Hoffland, E.; Kuikman, P.J.; Brussaard, L.

    2009-01-01

    There is considerable concern in Europe that soil organic matter (SOM) contents are declining, which would threaten both agriculture and the environment. We performed a trend analysis of SOM contents in sandy soils, using historic data from routine agricultural soil analyses. Data were selected from

  20. Experimental study on stability of sunken large diameter cylindrical structure on sandy seabed during construction period

    Institute of Scientific and Technical Information of China (English)

    秦崇仁; 庞红犁; 李世森; 张伟

    2002-01-01

    A systematic experimental research work is done for the stability of sunken large diameter cylinder during construction period. It is the first research that gives the method for assessing the stability of the larger diameter cylindrical structure, a set of values is derived also for the critical stability indices of the large diameter cylinder sunken to the sandy seabed.

  1. Toward a Unified Military Response: Hurricane Sandy and the Dual Status Commander

    Science.gov (United States)

    2015-04-01

    Ozzie Paez, “Emergency Managers’ Views on Improving Defense Support/ Military Assistance to Civil Authorities (DSCA/MACA) Educa - tion Programs...contrary, in fact. The prob- 74 lems that occurred during the Sandy response in most cases can be attributed largely to lack of formal educa - tion

  2. TOXICITY TRENDS DURING AN OIL SPILL BIOREMEDIATION EXPERIMENT ON A SANDY SHORELINE IN DELAWARE, USA

    Science.gov (United States)

    A 13-week, refereed, inter-agency toxicity testing program involving five bioassay methods was used to document the effectiveness of shoreline bioremediation to accelerate toxicity reduction of an oiled sandy shoreline at Fowler Beach, Delaware, USA. The study was part of an inte...

  3. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

    Science.gov (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  4. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China

    Science.gov (United States)

    Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang

    2007-01-01

    This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for...

  5. State of the art of the meiofauna of Brazilian Sandy Beaches

    Directory of Open Access Journals (Sweden)

    Tatiana Fabricio Maria

    Full Text Available Abstract In Brazil, meiofauna studies began in the middle of last century, but they adopted a purely taxonomical approach, describing species from various zoological groups. After this first step, this benthic group was largely neglected until the end of the 20th century when ecological studies began. We here provide a brief review of present knowledge of the meiofauna found on Brazilian sandy beaches to provide information for ReBentos (Coastal Benthic Habitats Monitoring Network. Our methodology consisted of a bibliographic survey undertaken using different datasets (Web of ScienceTM, SCOPUS, Google Scholar and Lattes Plataform. For the survey, we considered only those studies published till early 2015. Our analysis showed that the number of meiofauna studies has increased over the last two decades, though they are mainly still concentrated on the Southeast of Brazil. These studies aim to explain the distribution pattern of the meiofauna of the intertidal region of sandy beaches. Based on the results, we presented a discussion of three main topics, i.e., (a current knowledge of Brazilian sandy beach meiofauna, (b sampling strategies for monitoring of the meiofauna, and (c use of the meiofauna as a tool to assess climate change. We trust that this brief review will be useful as a starting point for the delineation of further climate change investigations into sandy beach meiofauna.

  6. 2012 USACE Post-Hurricane Sandy Topographic LiDAR: Eastern Long Island, New York

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR HURRICANE SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588...

  7. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged HUmic-Sandy Soil

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. R

  8. Improvement of Water Movement in an Undulating Sandy Soil Prone to Water Repellency

    NARCIS (Netherlands)

    Oostindie, K.; Dekker, L.W.; Wesseling, J.G.; Ritsema, C.J.

    2011-01-01

    The temporal dynamics of water repellency in soils strongly influence water flow. We investigated the variability of soil water content in a slight slope on a sandy fairway exhibiting water-repellent behavior. A time domain reflectometry (TDR) array of 60 probes measured water contents at 3-h

  9. Effects of Carboxymethylcelluloses (CMC) on Some Hydraulic Properties of Sandy Soil

    Institute of Scientific and Technical Information of China (English)

    ANDRY Henintsoa; INOUE Mitsuhiro; MORITANI Shigeoki; UZOMA Kingsley Chinyere

    2010-01-01

    The property of hydrophilic polymers capable absorbing huge volumes of water led to many practical applications of these new materials in arid regions for improving the water retention in sandy soils. Effects of four carboxymethylcelluloses (CMC), mixed at various rates with the sandy soil, on the water-holding capacity and hydraulic conductivity (Ks) when leached with distilled water (simulating rain), tap water, and saline water were evaluated. The maximum water absorption of CMCs ranged between 80 and 100 kg. kg-1 of polymer; however, the absorbent swelling capacity decreased significantly with increasing the salt concentration in the solution. The water absorption capacity of CMCs decreased significantly when incorporated in the sandy soil compared to that of the absorbent alone. Application of CMC increased significantly the available water content up to 3 ±0.5 times. All soils treated with CMCs showed a significant lower in Ks compared to the control soil. Meanwhile, Ks was found increased with increasing the salt concentration in the leaching solution. This understanding of characteristics of the absorbents and the interactions among absorbents, soil, and irrigation water quality would be of help in water management of sandy soil.

  10. Rain water transport and storage in a model sandy soil with hydrogel particle additives.

    Science.gov (United States)

    Wei, Y; Durian, D J

    2014-10-01

    We study rain water infiltration and drainage in a dry model sandy soil with superabsorbent hydrogel particle additives by measuring the mass of retained water for non-ponding rainfall using a self-built 3D laboratory set-up. In the pure model sandy soil, the retained water curve measurements indicate that instead of a stable horizontal wetting front that grows downward uniformly, a narrow fingered flow forms under the top layer of water-saturated soil. This rain water channelization phenomenon not only further reduces the available rain water in the plant root zone, but also affects the efficiency of soil additives, such as superabsorbent hydrogel particles. Our studies show that the shape of the retained water curve for a soil packing with hydrogel particle additives strongly depends on the location and the concentration of the hydrogel particles in the model sandy soil. By carefully choosing the particle size and distribution methods, we may use the swollen hydrogel particles to modify the soil pore structure, to clog or extend the water channels in sandy soils, or to build water reservoirs in the plant root zone.

  11. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    NARCIS (Netherlands)

    Bühring, S.I.; Ehrenhauss, S.; Kamp, A.; Moodley, L.; Prof. Witte, U.

    2006-01-01

    In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we

  12. 2012 USACE Post Hurricane Sandy Topographic LiDAR: Virginia and Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR HURRICANE SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert...

  13. Effects of DCD addition to slurry on nitrate leaching in sandy soils

    NARCIS (Netherlands)

    Corré, W.J.; Zwart, K.B.

    1995-01-01

    The effects of the addition of the nitrification inhibitor dicyandiamide (DCD) to cattle slurry, applied in autumn to an arable sandy soil, were investigated in a three-year field experiment in the Netherlands. Treatments included application of slurry with DCD in November and December, application

  14. Contribution of individual sorbents to the control of heavy metal activity in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    A multisurface model is used to evaluate the contribution of various sorption surfaces to the control of heavy metal activity in sandy soil samples at pH 3.7-6.1 with different sorbent contents. This multisurface model considers soil as a set of independent sorption surfaces, i.e. organic matter (NI

  15. Factors affecting N immobilisation/mineralisation kinetics for cellulose-, glucose- and straw-amended sandy soils

    NARCIS (Netherlands)

    Vinten, A.J.A.; Whitmore, A.P.; Bloem, J.; Howard, R.; Wright, F.

    2002-01-01

    The kinetics of nitrogen immobilization/mineralization for cellulose-, glucose- and straw-amended sandy soils were investigated in a series of laboratory incubations. Three Scottish soils expected to exhibit a range of biological activity were used: aloamy sand, intensively cropped horticultural soi

  16. Sediment yield computation of the sandy and gritty area based on the digital watershed model

    Institute of Scientific and Technical Information of China (English)

    LIU; Jiahong; WANG; Guangqian; LI; Tiejian; XUE; Hai

    2006-01-01

    The Yellow River is well known as a sediment-laden river, which is the main reason that it cannot be controlled as easily as other rivers. Many researchers, such as Qian Ning et al., have found that the sediment load of the Yellow River comes mainly from the sandy and gritty area of the Loess Plateau. Therefore, it is very important to simulate the sediment yield in this area. This paper proposes a method to compute the sediment production in the sandy and gritty area based on the digital watershed model. The suggested model is calibrated and validated in the Chabagou basin, which is a small catchment in the study area. Finally, the model simulates the sediment yield of the sandy and gritty area in 1967, 1978, 1983, 1994 and 1997, which represents a high water and high sediment year, a mean water and mean sediment year, a high water and low sediment year, a low water and high sediment year, and a low water and low sediment year separately. The simulation results, including the runoff depth and erosion modulus, can well explain the "low water and high sediment" phenomena in the Yellow River basin. The total amount of the sediment production and its distribution generated by the model is very useful for water and soil conservation in the sandy and gritty area of the Loess Plateau.

  17. Evaluation of a LIDAR Land-Based Mobile Mapping System for Monitoring Sandy Coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2011-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Understanding the morphology of the coast is essential for defense against flooding of the hinterland. Because most dramatic changes of the beach and the first dune row happen during storms, it is important to assess the state of th

  18. Evaluation of a laser land-based mobile mapping system for monitoring sandy coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2010-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Its morphology is essential for the defense against flooding of the hinterland. Therefore it is monitored on a yearly basis by Airborne Laser Scanning (ALS). However, it is recognized that most erosion of the beach and first dune ro

  19. Denitrification coupled to pyrite oxidation and changes in groundwater quality in a shallow sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Passier, H.F.; Cappellen, P. van

    2009-01-01

    This study focuses on denitrification in a sandy aquifer using geochemical analyses of both sediment and groundwater, combined with groundwater age dating (3H/3He). The study sites are located underneath cultivated fields and an adjacent forested area at Oostrum, The Netherland

  20. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    NARCIS (Netherlands)

    Cartaxana, P; Mendes, CR; van Leeuwe, MA; Brotas, [No Value

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on

  1. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    Science.gov (United States)

    Cartaxana, P.; Mendes, C. R.; van Leeuwe, M. A.; Brotas, V.

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on a per area basis (mg m -2) were comparable (down to 2 mm). Pigment analysis also revealed similar microphytobenthic communities in terms of algal classes. Diatoms were the dominant microalgae, but cyanophytes, euglenophytes and phanerogam debris were also present. For both muddy and sandy sediments, microphytobenthic biomass showed a high level of variability both within and between two consecutive years. Microphytobenthos was highly stratified in the mud, with most of the chlorophyll a occurring in the top 500 μm. In the sand, relatively constant concentrations were found throughout the sediment profile down to 3 mm. This is probably related to deeper light penetration in sandy sediment and/or increased physical mixing caused by invertebrate activity or overlying currents, leading to the burial of an important fraction of the microphytobenthic cells. Differences observed in the intensity of sediment coloration of muddy and sandy sediments might have resulted from the different vertical distribution of benthic biomass.

  2. Irrigation and nitrogen use efficiency of Thuja occidentalis grown on sandy soils

    NARCIS (Netherlands)

    Pronk, A.A.

    2004-01-01

    A combined conifer growth - soil water and nitrogen balance model was calibrated to simulate dry mass production and partitioning, water and nitrogen demand and nitrogen losses for Thuja occidentalis grown for two years on a sandy soil. Light interception was successfully described by the row-of-cub

  3. Importance of phytodetritus and microphytobenthos for heterotrophs in a shallow subtidal sandy sediment

    NARCIS (Netherlands)

    Evrard, V.; Huettel, M.; Cook, P.L.M.; Soetaert, K.; Heip, C.H.R.; Middelburg, J.J.

    2012-01-01

    The relative importance of allochthonous phytodetritus deposition and autochthonous microphytobenthos (MPB) production for benthic consumers in an organic carbon (C-org)-poor sandy sediment was assessed using a C-13-stable isotope natural abundance study combined with a dual C-13-tracer addition app

  4. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  5. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the

  6. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium....

  7. Transport of water and solutes in wettable and water repellent sandy soils

    NARCIS (Netherlands)

    Ritsema, C.J.; Dekker, L.W.

    1996-01-01

    The research yielded the following conclusions and results: preferential flow can be expected in recently deposited, loosely packed, wettable dune sands; preferential flow is common in most water-repellent sandy soils; distribution flow in topsoils isa process of major importance, resulting in a

  8. Assessing the relative role of climate change and human activities in sandy desertification of Ordos region,China

    Institute of Scientific and Technical Information of China (English)

    XU DuanYang; KANG XiangWu; LIU ZhiLi; ZHUANG DaFang; PAN JianJun

    2009-01-01

    Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches.A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China.Potential NPP and the difference between potential and actual NPP were selected as indicators to as-sess the relative role of climate change and human activities in sandy desertification,respectively.Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000.The results showed that although some local places experienced an expansion of sandy desertification,the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend.The relative role of climate change and human ac-tivities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes.In the reversion of sandy desertification,climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate decidu-ous scrubs in north east of Ordos region; however,human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region.In the expansion of sandy desertificallon,human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around com-mon boundary of Hanggin,Dalad Banners and Dongsheng City; however,climate change dominated the expansion of sandy desertification from 1991 to 2000,the expanded areas equably distributed

  9. 影响沙区赤松造林成活率的主要因素分析%Main Factors Affecting the Afforestation Survival Rate of Pinus densiflora in Sandy Areas

    Institute of Scientific and Technical Information of China (English)

    李云波; 宋佩东

    2015-01-01

    通过试验分析沙区赤松造林中采取不同整地方式、不同质量苗木及不同管护措施对造林成活率及生长量的影响,结果表明:伏前全面整地的赤松造林成活率、当年高生长最大,分别为93%和12.8 cm,玉米茬地好于现整现造地;不同等级、不同类型苗木中以容器苗造林成活率最高,为94.4%;不同立地条件以沙壤土的条件下造林苗木成活率最高,为95%。%The effects of different land preparation methods,quality of different seedlings and different management measures on survival rate and growth of Pinus densiflora were analyzed.Result shows that survival rate and height growth in the very year of Pinus densiflora with full preparation before the hot summer days are the highest,being 93% & 12.8 cm,respectively.Stub land of Zeamays is optimal than extempore soil preparation and extempore af-forestation.Survival rate of container seedlings among different grade and types of seedlings is the highest,being 94.4%;the survival rate under sandy loam is the highest,being 95%.

  10. Preliminary reconstruction of the desert and sandy land distributions in China since the last interglacial period

    Institute of Scientific and Technical Information of China (English)

    CHEN; Huizhong; SU; Zhizhu; YANG; Ping; DONG; Guangrong

    2004-01-01

    The desert and sandy land are the products of arid climate. The spatial distribution of modern deserts and sandy land in China and their relation to climate show following characteristics: arid and hyper-arid desert zones, at isohyet of less than 200 mm, are dominated by mobile dunes; semi-arid steppe and arid desert steppe with the precipitation between 200-400mm, are dominated by semi-fixed and fixed sand dunes; the precipitation of sub-humid forest grassland and humid forest zones with scattered fixed sand land is higher than 400 mm. With this as reference, in combination with considerable amount of paleoclimatic data in desert regions and adjacent regions, the distributions of desert and sandy land in China during the last interglacial period, the last glacial maximum (LGM), and the Holocene megathermal, were preliminarily reconstructed. The results compared with that of today show that the distribution of desert and sandy land in China was greatly dwindled during last interglacial period, and the mobile dune area was about two-thirds of that of today's, but greatly expanded during LGM. However, the dwindling area of desert and sandy land in the Holocene megathermal was smaller than that in the last interglacial period. The forcing mechanism was mainly related to the changes of East Asian winter and summer monsoon, south-northward swing of the westerlies and the variations of the Qinghai-Tibet Plateau monsoon intensity caused by global climate changes during the cold and warm intervals since the last interglacial period.

  11. Resource utilization and trophic niche width in sandy beach macrobenthos from an oligotrophic coast

    Science.gov (United States)

    Ortega-Cisneros, Kelly; de Lecea, Ander M.; Smit, Albertus J.; Schoeman, David S.

    2017-01-01

    One of the paradigms underlying sandy beach ecology is the overriding control by physical processes; thus, biological interactions (i.e. food availability, competition and predation) are believed to play a role structuring macrofaunal communities only in benign habitats such as dissipative beaches. Moreover, sandy beaches are characterized by low in-situ productivity, so their food webs rely heavily on marine inputs. Studies have shown that estuarine organic matter plays a key role in influencing the dynamics of marine ecosystems. However, very few studies have tested the role of estuarine input on sandy beaches. Here, we aim to determine the impact of estuarine input on the food web of a sandy beach macrobenthic community. To this end, particulate organic matter (POM) samples from the marine environment and the estuary, as well as macrobenthic samples from the beach, were analysed for their stable isotope (SI) signature. Our results indicated that the POM SI signatures were not different along the beach, but differences were recorded between marine and estuarine sources. Bayesian mixing models indicated that the organisms did not make use of the estuarine POM at the beginning of the wet season, but relied more heavily on this resource towards the end of the wet season. This leads to the conclusion that changes in estuarine flow throughout the wet season can impact the trophic structure of macrobenthos communities, confirming a link between lotic and marine communities. Moreover, SI signatures suggest that the species collected here exhibit overlapping trophic niches, indicating high level of inter-specific competition. This highlights that species in low-productivity areas, such as the one studied here, can experience high levels of competition even in physically controlled environments such as sandy beaches.

  12. Study of Sediments in the Yutian-Hotan Oasis,South Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on investigation of sediments in the Yutian-Hotan Oasis at the southern margin of the Tarim basin, 14C ages and grain-size and chemical element analyses, the following views are put forward in this paper.(1) Sediments in the Yutian-Hotan Oasis are composed chiefly of "oasis soil", similar to the recent oasis soil, i.e. brown desert soil, which was formed due to pedogenesis after aeolian sand (sandy loam) and dust (loess) of 3.32-6.64 j were deposited.(2) The ancient Yutian-Hotan Oasis represented by oasis soil was formed at 13000 a B.P. During the cold period of the past 13000 years, this region is characterized mainly by accumulation of sand and dust storms, and sandy oasis soil was developed in this region due to pedogenesis in an oasis environment; during the warm period, dust falls predominated along with certain current concomitants (lacustrine facies), and silty oasis soil was formed by pedogenesis. Owing to fluctuations of cold and warm climates since 13000 a B.P., sandy oasis soil was deposited alternately with silty oasis soil and lacustrine soils. Nevertheless, the Yutian-Hotan Oasis has been preserved and developing continuously towards the contemporary time.(3) At the latest, the oasis became an important site of human inhabitancy at 10000 a B.P., and since then it has been an important base for the propagation and activity of local people in the Tarim Basin.

  13. Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy

    Science.gov (United States)

    Kunz, Michael; Mühr, Bernhard; Schröter, Kai; Kunz-Plapp, Tina; Daniell, James; Khazai, Bijan; Wenzel, Friedemann; Vannieuwenhuyse, Marjorie; Comes, Tina; Münzberg, Thomas; Elmer, Florian; Fohringer, Joachim; Lucas, Christian; Trieselmann, Werner; Zschau, Jochen

    2013-04-01

    Hurricane Sandy was the last tropical cyclone of the 2012 Northern Atlantic Hurricane season that made landfall. It moved on an unusual track from the Caribbean to the East Coast of the United States from 24 to 30 October as a Category 1 and 2 Hurricane according to the Saffir-Simpson Scale. Along its path, the severe storm event caused widespread damage including almost 200 fatalities. In the early hours of 30 October, Sandy made landfall near Atlantic City, N.J. Sandy was an extraordinary event due to its multihazard nature and several cascading effects in the aftermath. From the hydro-meteorological perspective, most unusual was the very large spatial extent of up to 1,700 km. High wind speeds were associated with record breaking storm surges at the U.S. Mid- Atlantic and New England Coast during high (astronomical) tide, leading to widespread flooding. Though Sandy was not the most severe storm event in terms of wind speed and precipitation, the impact in the U.S. was enormous with total damage estimates of up to 90 billion US (own estimate from Dec. 2012). Although much better data emerge weeks after such an event, the Forensic Disaster Analysis (FDA) Task Force of the Center for Disaster Management and Risk Reduction Technology (CEDIM) made an effort to obtain a comprehensive and holistic overview of the causes, hazardous effects and consequences associated with Sandy immediately after landfall at the U.S. coast on 30 October 2012. This was done in an interdisciplinary way by collecting and compiling scattered and distributed information from available databases and sources via the Internet, by applying own methodologies and models for near-real time analyses developed in recent years, and by expert knowledge. This contribution gives an overview about the CEDIM-FDA analyses' results. It describes the situation that led to the extraordinary event, highlights the interaction of the tropical cyclone with other hydro-meteorological events, and examines the

  14. THE BIODIVERSITY AT SANDI BIRD SANCTUARY, HARDOI WITH SPECIAL REFERENCE TO MIGRATORY BIRDS

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2013-09-01

    Full Text Available Indian subcontinent plays host to a number of migratory birds in summers as well as winters. It is estimated that over hundred species of migratory birds fly to India, either in search of feeding grounds or to escape the severe winter of their native habitat. Sandi bird sanctuary was created in 1990 in order to protect and conserve the natural habitation and surroundings and also the marine vegetation for the migratory birds, as well as for the local people of the region. The term migration is used to describe movements of populations of birds or other animals. There are three types of migrants. One way to look at migration is to consider the distances traveled. The pattern of migration can vary within each category, but is most variable in short and medium distance migrants. The origin of migration is related to the distance traveled. The birds migrating through the area, take shelter on the river front before going to the Sandi Bird sanctuary. The birds generally migrate in the winter months of October-November-December. Bird sanctuary is a popular tourist location. Sandi particularly attracts ornithologists and bird watchers, as many rare migratory birds take refuge in the sanctuary. The bird watching camps arranged to observe the migratory birds at Sandi Bird Sanctuary in the month of October and November 2012. The migratory birds at Sandi Bird Sanctuary include great crested grebe, white storks, black lbis, glossy lbis, spoonbill, ruddy shelduck, pin tail, sholveller, spot bill duck, mallard, gadwall, wigeon, tufted pochard, gargancey teal, common teal, cotton teal, grey lag goose, coot, black tailed godwit, painted stock pin tail snipe, marsh sand piper, common tern, river tern, magpie robin, white wagtail, pied wagtail, common snipe, starlings, white lbis, red crested pochard, common pochard, painted stock, black lbis, curlew, Indian skimmer etc. The resident birds at Sandi Bird Sanctuary include little grebe, darter, purple heron, grey

  15. THE PROBLEMATIC OF SANDY LANDS IN PARANAVAI MUNICIPALITY –PR

    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo Freres Stipp

    2005-05-01

    Full Text Available The sandy lands are a process of scouring with sand forming a sandy area, which correspondsto a reworking of the sands due its constant mobility, involving the transformation of notsolids deposits is sandy areas. This work tried to establish the characterization of thisphenomenon of scouring with sand in a local level, occurring in arenaceous areas in theNortheast of the state of Paraná, specifically in the urban site of Paranavaí. It was also madean evaluation of the environmental degradation as well as different causes for what provokedthese sandy areas. Being an area with a high level of soil decomposition with the highwaysroutes crossing it, it was necessary, besides bibliographic data that allowed a theoretical basis,a research applied in order to supply subsides for future planning related to the spaceorganization. The evolution of the use and soil occupation in this area has been processedwithin an urban planning which considered by no account neither soil characteristic, thevegetation nor the predominant climate in that region. The mechanisms of region atmospherecirculation were analyzed, the alterations or attributes of the climate as well, aiming toidentify the genesis of the erosion sandy and possible time and space distribution. Initially, themain characteristics of the region were collected, components e processes working on the landmodel. It was observed how it worked and the use and occupation of the soil in past times andcurrently. During 2004, using the Environmental Fragility Letter, the areas of erosion wereidentified, ravines and strong erosion that compounds the first stages of the focused problem.The sandy land is a process that involves erosion, transport, e accumulation, meaning most oftimes the loosing of Biosphere productivity. For monitoring these risk areas some measuringcanes were made to measure the soil loss, which were used in several spots of erosion in theurban area in Paranavaí. The measurement happened in

  16. Effectiveness of the GAEC cross-compliance standard Ploughing in good soil moisture conditions in soil structure protection

    Directory of Open Access Journals (Sweden)

    Maria Teresa Dell'Abate

    2011-08-01

    Full Text Available Researches have been carried out within the framework on the EFFICOND Project, focused at evaluating the effectiveness of the standards of Good Agricultural and Environmental Conditions (GAECs established for Cross Compliance implementation under EC Regulation 1782/2003. In particular the standard 3.1b deals with soil structure protection through appropriate machinery use, with particular reference to ploughing in good soil moisture conditions. The study deals with the evaluation of soil structure after tillage in tilth and no-tilth conditions at soil moisture contents other than the optimum water content for tillage. The Mean Weight Diameter (MWD of water stable aggregates was used as an indicator of tillage effectiveness. The study was carried out in the period 2008-2009 at six experimental farms belonging to Research Centres and Units of the Italian Agricultural Research Council (CRA with different pedo-climatic and cropping conditions. Farm management and data collection in the different sites were carried out by the local CRA researchers and technicians. The comparison of MWD values in tilth and no tilth theses showed statistically significant differences in most cases, depending on topsoil texture. On clay, clay loam, silty clay, and silty clay loam topsoils a general and significant increase of MWD values under no tilth conditions were observed. No significant differences were observed in silt loam and sandy loam textures, probably due to the weak soil structure of the topsoils. Moreover, ploughing in good soil moisture condition determined higher crop production and less weed development than ploughing in high soil moisture conditions.

  17. 阿塔山水库壤土心墙堆石坝施工工艺%Construction Technology of Loam Core-wall Rock-fill Dam of Atashan Reservoir Dam

    Institute of Scientific and Technical Information of China (English)

    秦美荣

    2015-01-01

    阿塔山水库大坝是大型壤土心墙堆石坝,通过精心组织、科学管理、严把质量,填筑质量满足规范设计要求,保质保量完成合同任务。%Atashan reservoir dam is a large loam core-wall rock-fill dam. Through the elaborate organization, scientific management and strict quality control, the filling quality meets the requirements of the specification design, and the contract task is completed with good quality.

  18. Hurricane Sandy science plan: impacts of environmental quality and persisting contaminant exposure

    Science.gov (United States)

    Caskie, Sarah A.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry

  19. Hurricane Sandy science plan: impacts to coastal ecosystems, habitats, and fish and wildlife

    Science.gov (United States)

    Campbell, Warren H.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry

  20. Transitions in climate and energy discourse between Hurricanes Katrina and Sandy

    CERN Document Server

    Cody, Emily M; Bagrow, James P; Dodds, Peter Sheridan; Danforth, Christopher M

    2015-01-01

    Although climate change and energy are intricately linked, their explicit connection is not always prominent in public discourse and the media. Disruptive extreme weather events, including hurricanes, focus public attention in new and different ways, offering a unique window of opportunity to analyze how a focusing event influences public opinion. Simultaneously shaping and reflecting public discourse, media coverage of extreme weather events reflects public opinion of climate issues. Here we analyze climate and energy media coverage of Hurricanes Katrina (2005) and Sandy (2012) using topic models, mathematical techniques used to discover abstract topics within a set of documents. Our results demonstrate that post-Katrina media coverage does not contain a climate change topic, and the energy topic is limited to discussion of energy prices, markets, and the economy with almost no explicit linkages made between energy and climate change. In contrast, post-Sandy media coverage does contain a prominent climate ch...

  1. Effect of coastal urbanization on sandy beach coleoptera Phaleria maculata (Kulzer, 1959) in northern Chile.

    Science.gov (United States)

    González, Sergio A; Yáñez-Navea, Katherine; Muñoz, Mauricio

    2014-06-15

    The beetle Phaleria maculata is a common inhabitant of the upper intertidal fringe of Chilean beaches. Anthropogenic intervention in coastal areas has increased intensely, leading to changes in the flora and fauna of sandy beaches. To examine the impact of human activities on P. maculata, we studied several beaches along the northern Chilean coast. Beaches were characterized based on morphodynamics and the level of intervention, leading to the estimation of an "Urbanization Index" based on various indicators. The analysis showed a significant inverse correlation between the rate of urbanization and night sky quality. Larval and adult beetles were almost absent on beaches with high levels of urbanization. The results of simple and multiple correlations based on nMDS ordination showed an inverse relationship between increases in urbanization and the abundance of beetles. Because darkling beetles are very sensitive to human interventions on sandy beaches, we suggest that they are ideal indicator organisms for the health of these environments.

  2. Sandy Bridge—E顶级平台抢先展望

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Intel X79芯片组和LGA2011接口的sandy Bridge—E CPU(简称SNB—E)组成的整个平台开发代号为waimea Bay。这套新平台将完全解除目前SNB处理器以及6系列芯片组设下的超频限制,重新在BIOS中开放处理器外频调校,令骨灰玩家可以尽情挖掘SNB新架构处理器的潜能。除了超频,Sandy Bridge—E还可以为我们带来哪些呢?今天我们就带大家展望一下。

  3. Sandy grassland blowouts in Hulunbuir,northeast China:geomorphology,distribution,and causes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Altan MunkhDalai; FENG Zongwei; WANG Xiaoke; SUN Hongwei; ZHAO Jiaming; U Hurlee

    2007-01-01

    A sandy grassland blowout consists of an aeolian depression formed in top soil and the underlying sand deposit underlie,and the adjoining redeposit of sand derived from the depression. Research based on field survey and topographic mapping combined with aerophotograph interpretation reveals that: (1) All the three sand land tracts in Hulunbuir Grasslands are composed of blowout depressions and adjoining dunes, with interlaying remnants of sandy grasslands as background; (2) blowout depressions and their adjoining dunes can be classified according to their morphometric characteristics, development stages, and initiating factors; (3) blowouts develop mostly in the upper parts of sidelong aweather and sunward slopes inclining southwestward when west wind prevails; (4) initiation of blowouts is closely related with the coupling of extreme droughts and wide spread intense human disturbance to the fragile topsoil layer. The investigations indicate that key factors to prevent desertification are to protect grassland vegetation and topsoil.

  4. Pore-size distribution and compressibility of coarse sandy subsoil with added biochar

    DEFF Research Database (Denmark)

    Petersen, C. T.; Hansen, E.; Larsen, H. H.

    2016-01-01

    Sustainable agricultural production on coarse sandy soil is constrained by the restricted growth of roots, and poor water and nutrient retention. Amending the soil with biochar can reduce these problems, but the processes involved are not known in detail. We investigated in the laboratory...... the effects of two fine-grained gasification biochars made of straw (LTST) and other materials (LTSN) and of one fast pyrolysis straw biochar (FPST) on pore-size distribution and soil compressibility when added to coarse sandy subsoil. Water retention and therefore pore-size distribution were affected...... systematically. All biochars converted drainable pore space with pore diameters in the range 60–300 µm into water-retaining pores of size 0.2–60 µm, which was taken as an estimate of available water capacity (AWC). Effects were linear over the whole range of biochar (0–4% by mass). The effect of LTST and LTSN...

  5. Hurricane Sandy Economic Impacts Assessment: A Computable General Equilibrium Approach and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Riccardo [Los Alamos National Laboratory; Edwards, Brian Keith [Los Alamos National Laboratory

    2017-08-07

    Economists use computable general equilibrium (CGE) models to assess how economies react and self-organize after changes in policies, technology, and other exogenous shocks. CGE models are equation-based, empirically calibrated, and inspired by Neoclassical economic theory. The focus of this work was to validate the National Infrastructure Simulation and Analysis Center (NISAC) CGE model and apply it to the problem of assessing the economic impacts of severe events. We used the 2012 Hurricane Sandy event as our validation case. In particular, this work first introduces the model and then describes the validation approach and the empirical data available for studying the event of focus. Shocks to the model are then formalized and applied. Finally, model results and limitations are presented and discussed, pointing out both the model degree of accuracy and the assessed total damage caused by Hurricane Sandy.

  6. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    DEFF Research Database (Denmark)

    Bühring, Solveig I.; Ehrenhauss, Sandra; Kamp, Anja

    2006-01-01

    investigated the pathway of settling particulate organic carbon through the benthic food web. The diatom Ditylum brightwellii was labelled with the stable carbon isotope 13C and injected into incubation chambers. On-board incubations lasted 12, 30 and 132 h, while the in situ experiment was incubated for 32 h......In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we....... The study revealed a stepwise short-term processing of a phytoplankton bloom settling on a sandy sediment. After the 12 h incubation, the largest fraction of recovered carbon was in the bacteria (62%), but after longer incubation times (30 and 32 h in situ) the macrofauna gained more importance (15 and 48...

  7. Competition between n-alkane-assimilating yeasts and bacteria during colonization of sandy soil microcosms.

    Science.gov (United States)

    Schmitz, C; Goebel, I; Wagner, S; Vomberg, A; Klinner, U

    2000-07-01

    An n-alkane-assimilating strain of Candida tropicalis was selected in sandy soil inoculated with microorganisms from contaminated sites. Competition experiments with n-alkane utilizers from different strain collections confirmed that yeasts overgrow bacteria in sandy soil. Acidification of the soil is one of the colonization factors useful for the yeasts. It can be counteracted by addition of bentonite, a clay mineral with high ion exchange capacity, but not, however, by kaolin. Strains of different yeast species showed different levels of competitiveness. Strains of Arxula adeninivorans, Candida maltosa, and Yarrowia lipolytica overgrew strains of C. tropicalis, C. shehatae or Pichia stipitis. Two strains of C. maltosa and Y. lipolytica coexisted during several serial transfers under microcosm conditions.

  8. Distribution of transformed organic matter in structural units of loamy sandy soddy-podzolic soil

    Science.gov (United States)

    Kogut, B. M.; Yashin, M. A.; Semenov, V. M.; Avdeeva, T. N.; Markina, L. G.; Lukin, S. M.; Tarasov, S. I.

    2016-01-01

    The effect of land use types and fertilizing systems on the structural and aggregate composition of loamy sandy soddy-podzolic soil and the quantitative parameters of soil organic matter has been studied. The contribution of soil aggregates 2-1 mm in size to the total Corg reserve in the humus horizon is higher than the contributions of other aggregates by 1.3-4.2 times. Reliable correlations have been revealed between the contents of total (Corg), labile (Clab), and active (C0) organic matter in the soil. The proportion of C0 is 44-70% of Clab extractable by neutral sodium pyrophosphate solution. The contributions of each of the 2-1, 0.5-0.25, and humus horizon of loamy sandy soddy-podzolic soil, the active, slow, and passive pools contain 6-11, 34-65, and 26-94% of the total Corg, respectively.

  9. Response of corn silage (Zea mays L.) to zinc fertilization on a sandy soil under field and

    National Research Council Canada - National Science Library

    Saad Drissi; Abdelhadi Aït Houssa; Ahmed Bamouh; Mohamed Benbella

    2017-01-01

    The purpose of the experiments was to evaluate zinc (Zn) fertilization effect on growth, yield and yield components of corn silage grown on a sandy soil under field and outdoor container conditions...

  10. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar and digital elevation model (DEM) tile index

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data represents the tile index for lidar data collected for the U.S. Geological Survey in November 2012 following Hurricane Sandy, which made landfall in the...

  11. Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013.

    Science.gov (United States)

    Romanok, Kristin; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.

    2016-01-01

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  12. Sediment chemistry and toxicity in Barnegat Bay, New Jersey: Pre- and post-Hurricane Sandy, 2012-13.

    Science.gov (United States)

    Romanok, Kristin M; Szabo, Zoltan; Reilly, Timothy J; Defne, Zafer; Ganju, Neil K

    2016-06-30

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  13. 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New York City)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New York CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  14. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes

    Science.gov (United States)

    Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

    2017-01-01

    Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1–1.9]), depression (ORadj: 1.7 [1.3–2.2]), and PTSD (ORadj: 2.5 [1.8–3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01–1.12]) and PTSD (ORadj: 1.2 [1.1–1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5–2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1–1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms. PMID:28129410

  15. Soil-water characteristics of sandy soil and soil cement with and without vegetation

    OpenAIRE

    2014-01-01

    The use of soil cement as a growth medium was examined in this study. During the monitoring, green soil cement revealed diverse ecological values. The survival rates of plants in each soil conditions were higher than 80%,which was very promising. Furthermore, the survival rates dropped when the soil density reached95%, which means soil density might influence the survival rate of plant. Plant growth rates in sandy soil were higher than that in soil cement. In particular, low soil density faci...

  16. Effect of Land Cover Change on Soil Phosphorus Fractions in Southeastern Horqin Sandy Land, Northern China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qiong; ZENG De-Hui; FAN Zhi-Ping; D.K.LEE

    2008-01-01

    In the past 50 years, large areas of the Horqin sandy land were afforested to prevent desertification. Although the afforestation policy appears successful, many people now doubt whether it is suitable to plant trees with high density on the poor soils in semiarid regions. Little is known about the impacts of afforestation on the sandy soil properties, although the evaluation of these impacts is fundamental to judge the rationality of afforestation policy. Soil phosphorus (P) fractions, acid phosphomonoesterase activities, and other soil chemical properties were compared among five adjoining typical ecosystems on poor sandy soils in southeastern Horqin sandy land. The ecosystems studied are natural elm savanna, degraded grassland, Mongolian pine (Pinus sylvestris var. Mongolica) plantation, Chinese pine (Pinus tabulaeformis) plantation, and mixed plantation of Mongolian pine and poplar (Populus simonii). The results showed that organic P dominated soil P (47%-65%) was the principal source of available P. The degradation of elm savanna to grassland significantly reduced soil pH and resulted in an overall reduction in soil fertility, although slightly increased labile inorganic P. Grassland afforestation had no significant influence on soil pH, organic carbon, and total N but significantly reduced total P. Impacts of grassland afforestation on soil P fractions depended on tree species. Natural elm savanna had higher soil P conserving ability than artificial plantations. Therefore, with the aim of developing a sustainable ecosystem, we suggested that vegetations with low nutrient demand (particularly P) and efficient nutrient cycling would be more suitable for ecosystem restoration in the semiarid region.

  17. A modified criterion for wave-induced momentary liquefaction of sandy seabed

    OpenAIRE

    Wen-Gang Qi; Fu-Ping Gao

    2015-01-01

    The assessment of the wave-induced soil liquefaction plays a key role in the geotechnical design for offshore foundations. The underlying shortcomings of the existing momentary liquefaction criteria are identified and clarified by mechanism analyses and the recent field observations. A modified criterion for the wave-induced momentary liquefaction of a sandy seabed is given to describe the vertical pore-pressure distributions. An improved approximation of the momentary liquefaction depth is f...

  18. Detection of objects in sandy ground by an FM-CW radar

    OpenAIRE

    Yamaguchi, Y.(International Center for Elementary Particle Physics and Department of Physics, The University of Tokyo, Tokyo, Japan); Tsurugi, M.; Watanabe, Y.; Sengoku, M.; Kikuta, T.; Nishino, M; Tsunasaki, M.; Yamaguchi, Yoshio; Sengoku, Masakazu; 山口, 芳雄; 仙石, 正和

    1993-01-01

    An FM-CW radar system for the detection of objects buried in sandy ground is explored and applied to field measurement. The key factors for underground radar performance are the center frequency and the bandwidth determining the depth at which the radar can detect targets and the resolution in the range direction, respectively. To realize a practical underground radar, two ridged horn antennas are employed in the system, which are operative in the frequency range of 250-1000 MHz. The impedanc...

  19. Superstorm Sandy: Implications For Designing A PostCyber Attack Power Restoration System

    Science.gov (United States)

    2016-03-31

    the grid and other man-made threats. Differences among the industrial control systems (ICSs) utilities use to manage their operations pose an...and control sensors on which utilities rely to provide reliable and resilient service. Major utilities typically use energy management systems...storm’s likely path. By providing timely and accurate forecasts to emergency managers 74 FEMA, Hurricane Sandy FEMA After-Action Report. 75 US

  20. Retention of pesticides in sandy soil columns modified with a wood barrier

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Martin, M. J.; Rodriguez-Cruz, M. S.; Ordax, J. M.; Arienzo, M.

    2009-07-01

    Wood residues can be used as low-cost potential sorbents of hydrophobic pesticides in technologies aimed to prevent soil and water contamination and reduce the risk of environmental pollution produced by point pollution sources of these compounds. The objective of this work was to study the effect of a pine or oak sawdust barrier on the retention of Iinuron, alachlor and metalaxyl, with different hydrophobic character, in a sandy soil. (Author)

  1. A Study of Variations in Atmospheric Turbulence Kinetic Energy on a Sandy Beach

    Science.gov (United States)

    Koscinski, J. S.; MacMahan, J. H.; Wang, Q.; Thornton, E. B.

    2016-12-01

    A 6-m high, meteorological tower consisting six evenly spaced ultrasonic anemometers and temperature-relative humidity sensors was deployed at the high tide line on sandy, wave-dissipative, meso-tidal beach in southern Monterey Bay, CA in October 2015. The micro-meteorology study focus is to explore the momentum fluxes and turbulent kinetic energy influenced by the interaction between an intensive wave-breaking surf zone and a sandy beach associated with onshore & cross-shore winds, diurnal heating, and differences in ocean-air temperatures. The tower was deployed for approximately 1-month and experienced diurnal wind variations and synoptic storm events with winds measuring up to 10 m/s and an air temperature range of 5-28 oC. This beach environment was found to be primarily unstable in thermal stratification indicating that the air temperature is colder than underlying surface, either the ocean or the sandy beach. The drag coefficient was found to be dependent upon the atmospheric stability. Direct-estimates of atmospheric stability were obtained with the sonic anemometer. The direct estimates are a ratio of w*/u*, where the w*, vertically scaled buoyancy velocity, is greater than u*, horizontally scaled friction velocity. Hypotheses for the enhanced buoyancy are 1) diurnal heating of the sandy beach, 2) warmer ocean temperatures relative to air temperatures, and 3) the wave breaking within the surf zone. Further exploration into these hypotheses is conducted by using vertical tower sensor pairs for estimating the temporal variability of the mechanical shear production and buoyancy production terms in turbulent kinetic energy budget. These results are part of the Coastal Land Air Sea Interaction (CLASI) experiment.

  2. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes.

    Science.gov (United States)

    Lieberman-Cribbin, Wil; Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

    2017-01-01

    Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1-1.9]), depression (ORadj: 1.7 [1.3-2.2]), and PTSD (ORadj: 2.5 [1.8-3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01-1.12]) and PTSD (ORadj: 1.2 [1.1-1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5-2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1-1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms.

  3. Seminavis atlantica Garcia, a new psammic diatom (Bacillariophyceae from southern Brazilian sandy beaches

    Directory of Open Access Journals (Sweden)

    M Garcia

    Full Text Available The paper presents the description of Seminavis atlantica Garcia, a psammic marine diatom from dissipative sandy beaches from southern Brazil. It is characterized by its convex linear dorsal margin (37 to 50% of its length is in a straight line, linear ventral margin and raphe located very close to the ventral margin. Its morphology is compared to similar species such as Amphora clevei Grunow, Amphora angusta (Greg. Cleve var. orientalis Allem, Amphora ventricosa Gregory and Amphora eulesteinii Grunow.

  4. Dynamics of Small-Scale Topographic Heterogeneity in European Sandy Salt Marshes

    OpenAIRE

    Kelly Elschot; Bakker, Jan P.

    2016-01-01

    Heterogeneity can boost biodiversity, as well as increase the resilience of an ecosystem to changing environmental conditions; therefore, it is important to understand how topographic heterogeneity in ecosystems is formed. Sandy tidal marshes have a repetitive pattern of higher elevated hummocks surrounded by lower elevated depressions, representing topographic heterogeneity at the scale of a few square meters. The aims of this study were to determine when this topographic heterogeneity forms...

  5. The finding of a paleo-spruce timber in Hunshandak sandy land and its paleoecological significance

    Institute of Scientific and Technical Information of China (English)

    崔海亭; 刘鸿雁; 腰希申

    1997-01-01

    A paleo-sprucc (Picea jezoensis) timber dated to (10 040 + 100) a B. P. was found in the Hunshan-dak sandy land, Inner Mongolia, which is also one of the oldest timber found in China. Pollen and mammal fossil further evidence that theropencedrymion dominated by birch and spruce existed in this area in the late period of the earlier Holocene. This finding has great significance for the analysis of paleoclimate, paleovegetation and landscape development in this area.

  6. The Method of Calculating the Settlement of Weak Ground Strengthened with the Reinforced Sandy Piles

    Directory of Open Access Journals (Sweden)

    Maltseva Tatyana

    2016-01-01

    Full Text Available The paper presents an engineering method for calculating the weak clay base, strengthened with sandy piles reinforced along the contour. The method is based on the principle of layer-by-layer summation, which is used when designing the bases and foundations. The novelty of the suggested method lies in the taking account of the soil reaction along the pile lateral surface and the impact of external vertical loads on the vertical displacement of the base.

  7. Wind-dispersed Seed Deposition Patterns and Seedling Recruitment of Artemisia halodendron in a Moving Sandy Land

    OpenAIRE

    LI, FENG-RUI; Wang, Tao; ZHANG, AI-SHENG; ZHAO, LI-YA; KANG, LING-FEN; Chen, Wen

    2005-01-01

    • Background and Aims Artemisia halodendron is a native sub-shrub that occurs mainly in moving and semi-fixed sandy lands in Inner Mongolia, China. Information on the spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron inhabiting moving sandy lands is very limited. The aim of this study was to examine wind-dispersed seed deposition patterns and post-dispersal recruitment of A. halodendron seedlings.

  8. Climate-change impacts on sandy-beach biota: crossing a line in the sand.

    Science.gov (United States)

    Schoeman, David S; Schlacher, Thomas A; Defeo, Omar

    2014-08-01

    Sandy ocean beaches are iconic assets that provide irreplaceable ecosystem services to society. Despite their great socioeconomic importance, beaches as ecosystems are severely under-represented in the literature on climate-change ecology. Here, we redress this imbalance by examining whether beach biota have been observed to respond to recent climate change in ways that are consistent with expectations under climate change. We base our assessments on evidence coming from case studies on beach invertebrates in South America and on sea turtles globally. Surprisingly, we find that observational evidence for climate-change responses in beach biota is more convincing for invertebrates than for highly charismatic turtles. This asymmetry is paradoxical given the better theoretical understanding of the mechanisms by which turtles are likely to respond to changes in climate. Regardless of this disparity, knowledge of the unique attributes of beach systems can complement our detection of climate-change impacts on sandy-shore invertebrates to add rigor to studies of climate-change ecology for sandy beaches. To this end, we combine theory from beach ecology and climate-change ecology to put forward a suite of predictive hypotheses regarding climate impacts on beaches and to suggest ways that these can be tested. Addressing these hypotheses could significantly advance both beach and climate-change ecology, thereby progressing understanding of how future climate change will impact coastal ecosystems more generally.

  9. Exploring Water Level Sensitivity for Metropolitan New York during Sandy (2012 Using Ensemble Storm Surge Simulations

    Directory of Open Access Journals (Sweden)

    Brian A. Colle

    2015-06-01

    Full Text Available This paper describes storm surge simulations made for Sandy (2012 for the Metropolitan New York (NYC area using the Advanced Circulation (ADCIRC model forced by the Weather Research and Forecasting (WRF model. The atmospheric forecast uncertainty was quantified using 11-members from an atmospheric Ensemble Kalman Filter (EnKF system. A control WRF member re-initialized every 24 h demonstrated the capability of the WRF-ADCIRC models to realistically simulate the 2.83 m surge and 4.40 m storm tide (surge + astronomical tide above mean lower low water (MLLW for NYC. Starting about four days before landfall, an ensemble of model runs based on the 11 “best” meteorological predictions illustrate how modest changes in the track (20–100 km and winds (3–5 m s−1 of Sandy approaching the New Jersey coast and NYC can lead to relatively large (0.50–1.50 m storm surge variations. The ensemble also illustrates the extreme importance of the timing of landfall relative to local high tide. The observed coastal flooding was not the worst case for this particular event. Had Sandy made landfall at differing times, locations and stages of the tide, peak water levels could have been up to 0.5 m higher than experienced.

  10. Personality diatheses and Hurricane Sandy: effects on post-disaster depression

    Science.gov (United States)

    Kopala-Sibley, D. C.; Kotov, R.; Bromet, E. J.; Carlson, G. A.; Danzig, A. P.; Black, S. R.; Klein, D. N.

    2015-01-01

    Background According to diathesis–stress models, personality traits, such as negative emotionality (NE) and positive emotionality (PE), may moderate the effects of stressors on the development of depression. However, relatively little empirical research has directly examined whether NE and PE act as diatheses in the presence of stressful life events, and no research has examined whether they moderate the effect of disaster exposure on depressive symptoms. Hurricane Sandy, the second costliest hurricane in US history, offers a unique opportunity to address these gaps. Method A total of 318 women completed measures of NE and PE 5 years prior to Hurricane Sandy. They were also assessed for lifetime depressive disorders on two occasions, the latter occurring an average of 1 year before the hurricane. Approximately 8 weeks after the disaster (mean = 8.40, s.d. = 1.48 weeks), participants completed a hurricane stress exposure questionnaire and a measure of current depressive symptoms. Results Adjusting for lifetime history of depressive disorders, higher levels of stress from Hurricane Sandy predicted elevated levels of depressive symptoms, but only in participants with high levels of NE or low levels of PE. Conclusions These findings support the role of personality in the development of depression and suggest that personality traits can be useful in identifying those most vulnerable to major stressors, including natural disasters. PMID:26619902

  11. Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil.

    Science.gov (United States)

    Chen, G C; He, Z L; Stoffella, P J; Yang, X E; Yu, S; Calvert, D

    2006-01-01

    There is increasing concern over P leaching from sandy soils applied with water-soluble P fertilizers. Laboratory column leaching experiments were conducted to evaluate P leaching from a typical acidic sandy soil in Florida amended with DPR fertilizers developed from dolomite phosphate rock (DPR) and N-Viro soil. Ten leaching events were carried out at an interval of 7 days, with a total leaching volume of 1,183 mm equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachates were collected and analyzed for total P and inorganic P. Phosphorus in the leachate was dominantly reactive, accounting for 67.7-99.9% of total P leached. Phosphorus leaching loss mainly occurred in the first three leaching events, accounting for 62.0-98.8% of the total P leached over the whole period. The percentage of P leached (in the total P added) from the soil amended with water-soluble P fertilizer was higher than those receiving the DPR fertilizers. The former was up to 96.6%, whereas the latter ranged from 0.3% to 3.8%. These results indicate that the use of N-Viro-based DPR fertilizers can reduce P leaching from sandy soils.

  12. [Monitoring of water and salt transport in silt and sandy soil during the leaching process].

    Science.gov (United States)

    Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei

    2012-11-01

    Water and salt transport in soil and its mechanism is the key point of the saline soil research. The dynamic rule of water and transport in soil during the leaching process is the theoretical basis of formation, flush, drainage and improvement of saline soil. In this study, a vertical infiltration experiment was conducted to monitor the variation in the resistivity of silt and sandy soil during the leaching process by the self-designed automatic monitoring device. The experimental results showed that the peaks in the resistivity of the two soils went down and faded away in the course of leaching. It took about 30 minutes for sandy soil to reach the water-salt balance, whereas the silt took about 70 minutes. With the increasing leaching times, the desalination depth remained basically the same, being 35 cm for sandy soil and 10 cm for the silt from the top to bottom of soil column. Therefore, 3 and 7 leaching processes were required respectively for the complete desalination of the soil column. The temporal and spatial resolution of this monitoring device can be adjusted according to the practical demand. This device can not only achieve the remote, in situ and dynamic monitoring data of water and salt transport, but also provide an effective method in monitoring, assessment and early warning of salinization.

  13. Attitudinal Determinants of Local Public Health Workers' Participation in Hurricane Sandy Recovery Activities.

    Science.gov (United States)

    Errett, Nicole A; Egan, Shannon; Garrity, Stephanie; Rutkow, Lainie; Walsh, Lauren; Thompson, Carol B; Strauss-Riggs, Kandra; Altman, Brian; Schor, Kenneth; Barnett, Daniel J

    2015-01-01

    Local health departments play a critical role in short-, intermediate-, and long-term recovery activities after a public health emergency. However, research has not explored attitudinal determinants of health department workers' participation in the recovery phase following a disaster. Accordingly, this qualitative investigation aims to understand perceived facilitators and barriers to performing recovery-related activities following Hurricane Sandy among local health department workers. In January 2014, 2 focus groups were conducted in geographically representative clusters of local health departments affected by Hurricane Sandy (1 cluster in Maryland and 1 cluster in New Jersey). Focus groups were recorded, transcribed verbatim, and analyzed to qualitatively assess attitudes toward Hurricane Sandy recovery activities. This analysis identified 5 major thematic categories as facilitators and barriers to participation in recovery activities: training, safety, family preparedness, policies and planning, and efficacy. Systems that support engagement of health department personnel in recovery activities may endeavor to develop and communicate intra- and interjurisdictional policies that minimize barriers in these areas. Development and implementation of evidence-informed curricular interventions that explain recovery roles may also increase local health department worker motivation to participate in recovery activities.

  14. Utilization of geotextile tube for sandy and muddy coastal management: a review.

    Science.gov (United States)

    Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il

    2014-01-01

    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.

  15. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    Science.gov (United States)

    Lee, Siew Cheng; Hashim, Roslan; Motamedi, Shervin; Song, Ki-Il

    2014-01-01

    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper. PMID:24955408

  16. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  17. Fire impacts on water repellency of sandy soils in SW Spanish coast

    Science.gov (United States)

    Jordán, Antonio; Zavala, Lorena M.; Gordillo-Rivero, Ángel J.; Muñoz-Rojas, Miriam; Keesstra, Saskia; Cerdá, Artemi

    2017-04-01

    Although water repellency of sandy soils from dune areas and their consequences (irregular wetting front, preferential flow pathways) are well studied, there is not much information about the effect of fire on hydrophobicity and its consequences in these areas. In this paper we study the in-depth variation of water repellency of burnt sandy soils from south-western Spain. Generally, it was observed that water repellency from unburnt forest soils is relatively higher than in shrublands and grasslands (where the lowest values were observed). However, the impact of fire caused a strong increase of hydrophobicity in the first two cases, with no major differences between them. This study confirms the presence of natural water repellency in sandy soils, as well as some of its consequences (irregular infiltration or increased surface water flow) depending on the type of vegetation, although the differences observed in burnt soils suggest that, although the composition of vegetation is important in the formation of natural water repellency, organic matter content is much more important in the case of burnt soils.

  18. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

    Directory of Open Access Journals (Sweden)

    Baille Wiebke

    2016-01-01

    Full Text Available In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand grain. Wetting induced collapse of the pseudo-grains is presumed to be one of the possible mechanisms triggering liquefaction. In the present study, the effect of larger voids on the wetting induced deformation behaviour of sandy soils is experimentally investigated by laboratory box tests. The deformation field in the sample during wetting was measured using Digital Image Correlation (DIC technique. The results show that the observed deformations are affected by the pore size distribution, thus the amount of voids between the pseudo-grains (macro-void ratio and the voids inside the pseudo-grains (matrix void ratio. The global void ratio of a sandy soil is not sufficient as single state parameter, but the pore size distribution has to be taken into account, experimentally as well as in modelling.

  19. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    Directory of Open Access Journals (Sweden)

    Siew Cheng Lee

    2014-01-01

    Full Text Available Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However, for the muddy coasts, mangrove rehabilitation and conservation were additional concerns in coastal management schemes. The mangrove forests are natural barriers which can be found on the muddy coasts of many tropical countries. In this paper, the viability of geotextile tubes in sandy and muddy beaches was analysed. The advantages and disadvantages of the utilization of geotextile tubes in coastal management were discussed based on the experiences from the tropical countries such as Mexico, Malaysia, and Thailand. From the case studies, impressive improvements in coastal restoration after installation of geotextile tubes were shown. Based on the discussion, several recommendations to improve the application of geotextile tubes were suggested in this paper.

  20. Evacuation of Intensive Care Units During Disaster: Learning From the Hurricane Sandy Experience.

    Science.gov (United States)

    King, Mary A; Dorfman, Molly V; Einav, Sharon; Niven, Alex S; Kissoon, Niranjan; Grissom, Colin K

    2016-02-01

    Data on best practices for evacuating an intensive care unit (ICU) during a disaster are limited. The impact of Hurricane Sandy on New York City area hospitals provided a unique opportunity to learn from the experience of ICU providers about their preparedness, perspective, roles, and activities. We conducted a cross-sectional survey of nurses, respiratory therapists, and physicians who played direct roles during the Hurricane Sandy ICU evacuations. Sixty-eight health care professionals from 4 evacuating hospitals completed surveys (35% ICU nurses, 21% respiratory therapists, 25% physicians-in-training, and 13% attending physicians). Only 21% had participated in an ICU evacuation drill in the past 2 years and 28% had prior training or real-life experience. Processes were inconsistent for patient prioritization, tracking, transport medications, and transport care. Respondents identified communication (43%) as the key barrier to effective evacuation. The equipment considered most helpful included flashlights (24%), transport sleds (21%), and oxygen tanks and respiratory therapy supplies (19%). An evacuation wish list included walkie-talkies/phones (26%), lighting/electricity (18%), flashlights (10%), and portable ventilators and suction (16%). ICU providers who evacuated critically ill patients during Hurricane Sandy had little prior knowledge of evacuation processes or vertical evacuation experience. The weakest links in the patient evacuation process were communication and the availability of practical tools. Incorporating ICU providers into hospital evacuation planning and training, developing standard evacuation communication processes and tools, and collecting a uniform dataset among all evacuating hospitals could better inform critical care evacuation in the future.

  1. New land-based method for surveying sandy shores and extracting DEMs: the INSHORE system.

    Science.gov (United States)

    Baptista, Paulo; Cunha, Telmo R; Matias, Ana; Gama, Cristina; Bernardes, Cristina; Ferreira, Oscar

    2011-11-01

    The INSHORE system (INtegrated System for High Operational REsolution in shore monitoring) is a land-base survey system designed and developed for the specific task of monitoring the evolution in time of sandy shores. This system was developed with two main objectives: (1) to produce highly accurate 3D coordinates of surface points (in the order of 0.02 to 0.03 m); and (2) to be extremely efficient in surveying a beach stretch of several kilometres. Previous tests have demonstrated that INSHORE systems fulfil such objectives. Now, the usefulness of the INSHORE system as a survey tool for the production of Digital Elevation Models (DEMs) of sandy shores is demonstrated. For this purpose, the comparison of DEMs obtained with the INSHORE system and with other relevant survey techniques is presented. This comparison focuses on the final DEM accuracy and also on the survey efficiency and its impact on the costs associated with regular monitoring programmes. The field survey method of the INSHORE system, based on profile networks, has a productivity of about 30 to 40 ha/h, depending on the beach surface characteristics. The final DEM precision, after interpolation of the global positioning system profile network, is approximately 0.08 to 0.12 m (RMS), depending on the profile network's density. Thus, this is a useful method for 3D representation of sandy shore surfaces and can permit, after interpolation, reliable calculations of volume and other physical parameters.

  2. Hurricane Sandy washover deposits on southern Long Beach Island, New Jersey

    Science.gov (United States)

    Bishop, James M.; Richmond, Bruce M.; Zaremba, Nicholas J.; Lunghino, Brent D.; Kane, Haunani H.

    2016-07-22

    Sedimentologic and topographic data from Hurricane Sandy washover deposits were collected from southern Long Beach Island, New Jersey, in order to document changes to the barrier-island beaches, dunes, and coastal wetlands caused by Hurricane Sandy and subsequent storm events. These data will provide a baseline dataset for use in future coastal change descriptive and predictive studies and assessments. The data presented here were collected as part of the U.S. Geological Survey’s Barrier Island and Estuarine Wetland Physical Change Assessment Project (http://coastal.er.usgs.gov/sandy-wetland-assessment/), which aims to assess ecological and societal vulnerability that results from long- and short-term physical changes to barrier islands and coastal wetlands. This report describes data that were collected in April 2015, approximately 2½ years after Hurricane Sandy’s landfall on October 29, 2012. During the field campaign, washover deposits were photographed and described, and sediment cores, sediment samples, and surface-elevation data were collected. Data collected during this study, including sample locations and elevations, core photographs, computed tomography scans, descriptive core logs, sediment grain-size data, and accompanying Federal Geographic Data Committee metadata, are available in the associated U.S. Geological Survey data release (Bishop and others, 2016; http://dx.doi.org/10.5066/F7PK0D7S).

  3. Application of Wenner Configuration to Estimate Soil Water Content in Pine Plantations on Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To estimate the mean value of surface soil water content rapidly, accurately, and nonintrusively, field investigations on soil electrical resistivity (SER) with the Yokogawa 324400 earth resistivity meter and the surface (0-150 cm) soil water content (SWC) with time domain reflectometry (TDR), together with the abiotic factors including soil texture, structure,and salinity concentrations were conducted in the Mongolian pine (Pinus sylvestris var. mongolica) plantations on a sandy land. The measurement of SER was based on the 4-probe Wenner configuration method. Relationships between the values of SWC and SER were obtained based on analysis of the abiotic factors of the research site, which play a key role in affecting the soil electrical resistivity. Results indicate that the SER meter could be used to estimate the mean value of SWC in the Mongolian pine plantations on the sandy land during the growing seasons. The bulky nature of the equipment simplified the cumbersome measurements of soil water content with the general methods. It must be noted that the Wenner configuration method could only provide the mean values of the SWC, and the soil texture, structure,temperature, and solute concentrations influenced the SER and further affected the estimation of the SWC by the SER meter. Therefore, the results of this study could be applied on a sandy land during the growing seasons only. However,the SWC of other soil types also may be obtained according to the individual soil types using the procedures of this study.

  4. Trade-offs between soil hydrology and plant disease effects after biochar amendment in sandy soil

    Science.gov (United States)

    Verheijen, Frank; Silva, Flavio; Amaro, Antonio; Pinto, Gloria; Mesquita, Raquel; Jesus, Claudia; Alves, Artur; Keizer, Jacob

    2015-04-01

    Biochar can affect multiple soil-based ecosystem services to varying extents, leading to trade-offs. Improvements in plant-available water have predominantly been found at high biochar application rates in sandy soils. Reductions in plant diseases after biochar application have been found in various horticultural plants, and trees such as maple and oak, mostly at relatively low biochar application rates. Serious damage to Eucalyptus globulus has been reported since 1999 when frequent and severe defoliation of young trees was observed, and eucalypts are the major tree species in commercial forestry plantations of Portugal, forming an important economic activity. Here we investigated simultaneous effects on plant available water and on disease suppression of eucalypt, in a completely randomised full factorial greenhouse pot experiment, using a range of woody feedstock biochar concentrations in sandy soil. Treatments included plant inoculation with the fungus Neofusicoccum kwambonambiense and cycles of acute drought stress. Preliminary results showed delayed wilting for plants treated with 3-6% biochar, but also increased stem lesion length. These results suggest a trade-off between effects on water availability and disease for Eucalyptus globulus plants in the selected sandy soil amended with this specific biochar, at the selected application rates.

  5. Using humic acid for remediation of sandy soils contaminated by heavy metal

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper presents the development of a new remediation technology for contaminated sandy soil using humic acid (HA). Distribution of amount of Cr (VI) in the aqueous or solid system containing humic acid and sandy soil, was studied using batch experiments, es-pecially for effects of reaction time, pH, concentrations, temperature and irradiation on the reduction of Cr (VI), and the optimum reaction conditions. The results indicated a significant increase of the adsorption of Cr (VI) because of the complexion reaction between HA and Cr (VI) that occurred under acidic condition. The reaction mechanisms of HA with chromium on sand surfaces were certified. Thus it came to a conclusion that HA could be used effectively on remediation of Cr (VI)-contaminated soil and groundwater in a wide range of pH, with or without sunlight. These results suggest that the organic-inorganic complex-such as sandy soils coated with humic substances-is important as a metal reservoir in the environment.

  6. Bioremediating silty soil contaminated by phenanthrene, pyrene ...

    African Journals Online (AJOL)

    sunny t

    INTRODUCTION. Polycyclic ... it is environmentally benign and less invasive. Of the ... evolved microbial species and the exploration to enhance ... Gram-positive species. ...... of polycyclic aromatic hydrocarbons by the Chilean white-rot fungus.

  7. The status of sandy beach science: Past trends, progress, and possible futures

    Science.gov (United States)

    Nel, Ronel; Campbell, Eileen E.; Harris, Linda; Hauser, Lorenz; Schoeman, David S.; McLachlan, Anton; du Preez, Derek R.; Bezuidenhout, Karien; Schlacher, Thomas A.

    2014-10-01

    Open-ocean sandy beaches are coastal ecosystems with growing relevance in the face of global change. They provide key ecosystem services, such as storm buffering, nutrient cycling, water purification, nursery habitats for resource species, and feeding-breeding habitats for focal species (e.g. endangered sea turtles and shorebirds), and have also become nodes for economic development and cultural use. As a result, beaches face a range of threats, primarily from extractive use, habitat modification and development, sea-level rise and coastal squeeze. Consequently, balancing conservation of the ecosystem and sustainable use of the goods and services is particularly important for sandy shores. Thus, the only way to ensure their protection and continued provision of their valuable services, especially in a period of rapid global change, will be to apply knowledge generated from sound science in beach conservation and management. Here we aim to (1) identify and outline the broad ecological paradigms in sandy beach science; (2) report on a citation analysis of the published literature of the past 63 years (1950-2013) to provide context regarding the topics and location of research, the size and institutional composition of the research teams; and (3) investigate whether beach ecology can and has been incorporated into integrated coastal zone management practices. Past research was framed by specific paradigms (chiefly the Swash Exclusion Hypothesis and derivatives), which can be identified with distinct principles and concepts unique to beaches. Most of the sandy beach literature comes from only a few countries (dominated by USA, South Africa, Brazil and Italy), published by small research teams (theory. Despite the constraints, beach science is responding to new challenges, with increasing use of the latest techniques. However, research in conservation and management specifically remains limited, with stronger focus on anthropogenic impacts, in turn leading to management

  8. Challenges in estimating the health impact of Hurricane Sandy using macro-level flood data.

    Science.gov (United States)

    Lieberman-Cribbin, W.; Liu, B.; Schneider, S.; Schwartz, R.; Taioli, E.

    2016-12-01

    Background: Hurricane Sandy caused extensive physical and economic damage but the long-term health impacts are unknown. Flooding is a central component of hurricane exposure, influencing health through multiple pathways that unfold over months after flooding recedes. This study assesses concordance in Federal Emergency Management (FEMA) and self-reported flood exposure after Hurricane Sandy to elucidate discrepancies in flood exposure assessments. Methods: Three meter resolution New York State flood data was obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. FEMA data was compared to self-reported flood data obtained through validated questionnaires from New York City and Long Island residents following Sandy. Flooding was defined as both dichotomous and continuous variables and analyses were performed in SAS v9.4 and ArcGIS 10.3.1. Results: There was a moderate agreement between FEMA and self-reported flooding (Kappa statistic 0.46) and continuous (Spearman's correlation coefficient 0.50) measures of flood exposure. Flooding was self-reported and recorded by FEMA in 23.6% of cases, while agreement between the two measures on no flooding was 51.1%. Flooding was self-reported but not recorded by FEMA in 8.5% of cases, while flooding was not self-reported but indicated by FEMA in 16.8% of cases. In this last instance, 84% of people (173/207; 83.6%) resided in an apartment (no flooding reported). Spatially, the most concordance resided in the interior of New York City / Long Island, while the greatest areas of discordance were concentrated in the Rockaway Peninsula and Long Beach, especially among those living in apartments. Conclusions: There were significant discrepancies between FEMA and self-reported flood data. While macro-level FEMA flood data is a relatively less expensive and faster way to provide exposure estimates spanning larger geographic areas affected by Hurricane Sandy than micro-level estimates from cohort studies, macro

  9. The Department of the Interior Strategic Sciences Group and its Response to Hurricane Sandy

    Science.gov (United States)

    Ludwig, K. A.; Machlis, G. E.; Applegate, D.

    2013-12-01

    This presentation will describe the history, mission, and current activities of the newly formed Department of the Interior (DOI) Strategic Sciences Group (SSG), with a focus on its response to Hurricane Sandy and lessons learned from using scenario building to support decision making. There have been several environmental crises of national significance in recent years, including Hurricane Katrina (2005), large-scale California wildfires (2007-2008), the Deepwater Horizon oil spill (2010), and Hurricane Sandy (2012). Such events are complex because of their impacts on the ecology, economy, and people of the affected locations. In these and other environmental disasters, the DOI has had significant responsibilities to protect people and resources and to engage in emergency response, recovery, and restoration efforts. In recognition of the increasingly critical role of strategic science in responding to such complex events, the DOI established the SSG by Secretarial Order in 2012. Its purpose is to provide the DOI with science-based assessments and interdisciplinary scenarios of environmental crises affecting Departmental resources; rapidly assemble interdisciplinary teams of scientists from government, academia, and non-governmental organizations to conduct such work; and provide results to DOI leadership as usable knowledge to support decision making. March 2013 was the SSG's first deployment since its formation. The SSG's charge was to support DOI's participation on the Hurricane Sandy Rebuilding Task Force by developing scenarios of Hurricane Sandy's environmental, economic, and social consequences in the New York/New Jersey area and potential interventions that could improve regional resilience to future major storms. Over the course of one week, the SSG Sandy team (Operational Group Sandy) identified 13 first-tier consequences and 17 interventions. The SSG briefed DOI leadership, Task Force representatives, and other policy makers in both Washington, DC and

  10. Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land, China

    Institute of Scientific and Technical Information of China (English)

    ChaoFeng Fu; JingBo Zhao; FanMin Mei; TianJie Shao; Jun Zuo

    2015-01-01

    Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the south-eastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that: (1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope. (2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune. (3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture. (4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indi-cating that shrubs are more effective in inhibiting wind erosion in the sandy land area.

  11. 饱和粉细砂层锚索预应力变化规律监测分析%Monitoring and analysis of variation of anchor prestress in saturated silty sand condition

    Institute of Scientific and Technical Information of China (English)

    刘波; 张功; 周浩亮; 李东阳; 娄学谦; 黄冕; 王学庆

    2014-01-01

    锚索的预应力损失在工程建设中不可忽视,工程的场地环境条件成为影响锚索预应力损失的主因。饱和粉细砂层较其他地质条件更为复杂敏感,更易引起锚索预应力值的损失。通过对廊坊市某深基坑工程锚索预应力值的实时监测,结合工程环境,分析饱和粉细砂层中造成锚索预应力值变化的原因。结果表明,施工过程、张拉过程以及环境因素都影响锚索预应力的变化,其中开挖过程的影响最明显,预应力值的变化率最大值达79.1%;瞬时卸载造成预应力值22.8%~59.2%的损失。对饱和粉细砂层中锚索预应力变化规律的研究分析结论可为类似地质环境的工程建设提供经验。%Prestress loss of anchor cable should not be neglected in engineering construction. The cause of prestress loss is usually related to engineering site condition. The saturated silty sand is more complicated and sensitive than other geological conditions, which is more likely to cause prestress loss. Through real-time monitoring of anchor prestress of a deep foundation pit in Langfang city, combining with the engineering environment, factors influencing on variation of anchor prestress are analyzed. The results show that the process of construction, tension and environmental factors affect the variation of prestress. The most obvious impact is the excavation process; and the maximum rate of variation of prestress value is 79.1%; instantaneous unloading causes values of prestress loss between 22.8% to 59.2%. The influence of construction process is most obvious. Experience for similar geological engineering construction is provided through the research and analysis of variation law of anchor prestress.

  12. Supplemental Material for: Examining the Roles of the Easterly Wave Critical Layer and Vorticity Accretion During the Tropical Cyclogenesis of Hurricane Sandy

    Science.gov (United States)

    2014-01-01

    Hurricane Sandy Louis L. Lussier III, _ Blake Rutherford, Michael T. Montgomery and Mark A. Boothe Naval Postgraduate School, Monterey, California...et al. (2009), and tested herein for the case of Hurricane Sandy (2012), provides a comprehensive description of the dynamics and thermodynamics...During the Tropical Cyclogenesis of Hurricane Sandy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  13. Environmental and agricultural benefits of a management system designed for sandy loam soils of the humid tropics Benefícios ambientais e agronômicos de um agrossistema definido para solos de textura franco arenosa do trópico úmido

    Directory of Open Access Journals (Sweden)

    Alana das Chagas Ferreira Aguiar

    2009-10-01

    Full Text Available A sustainable management of soils with low natural fertility on family farms in the humid tropics is a great challenge and overcoming it would be an enormous benefit for the environment and the farmers. The objective of this study was to assess the environmental and agronomic benefits of alley cropping, based on the evaluation of C sequestration, soil quality indicators, and corn yields. Combinations of four legumes were used in alley cropping systems in the following treatments: Clitoria fairchildiana + Cajanus cajan; Acacia mangium + Cajanus cajan; Leucaena leucocephala + Cajanus cajan; Clitoria fairchildiana + Leucaena leucocephala; Leucaena leucocephala + Acacia mangium and a control. Corn was used as a cash crop. The C content was determined in the different compartments of soil organic matter, CEC, available P, base saturation, percentage of water saturation, the period of the root hospitality factor below the critical level and corn yield. It was concluded that alley cropping could substitute the slash and burn system in the humid tropics. The main environmental benefit of alley cropping is the maintenance of a dynamic equilibrium between C input and output that could sustain up to 10 Mg ha-1 of C in the litter layer, decreasing atmospheric CO2 levels. Alley cropping is also beneficial from the agricultural point of view, because it increases base saturation and decreases physical resistance to root penetration in the soil layer 0 - 10 cm, which ensures the increase and sustainability of corn yield.O manejo sustentável dos solos de baixa fertilidade natural na agricultura familiar do trópico tem sido um grande desafio, que, se vencido, resultará em vantagens para o ambiente e para os agricultores. Este trabalho foi realizado com o objetivo de avaliar os benefícios ambiental e agronômico de um cultivo em aleias, por meio da determinação do C sequestrado, dos indicadores da qualidade do solo e da produtividade da cultura do milho. Foram utilizadas combinações de quatro leguminosas, formando os tratamentos: Clitoria fairchildiana + Cajanus cajan; Acacia mangium + Cajanus cajan; Leucaena leucocephala + Cajanus cajan; Clitoria fairchildiana + Leucaena leucocephala; Leucaena leucocephala + Acacia mangium; e testemunha. O milho foi utilizado como cultura econômica. Foram determinados o teor de C nos vários compartimentos da matéria orgânica do solo, a CTC, o P disponível, a saturação por bases, a percentagem de saturação por água, o período do fator hospitalidade da raiz abaixo do nível critico e a produtividade da cultura do milho. Conclui-se que o cultivo em aleias pode substituir o corte e a queima no trópico úmido com vantagens ambientais, diminuindo a quantidade de CO2 atmosférico por meio da manutenção de um equilíbrio dinâmico entre entrada e saída de C, que pode sustentar até 10 Mg ha-1 desse elemento na liteira. Do ponto de vista agronômico, os benefícios do cultivo em aleias foram o aumento da saturação por bases e a diminuição da resistência física à penetração das raízes na camada de 0 a 10 cm, o que propiciou o aumento e a sustentação da produtividade da cultura do milho.

  14. 吉林省西部土地沙化动态变化%Spatial distribution of sandy desertification change in the west of Jilin Province

    Institute of Scientific and Technical Information of China (English)

    刘惠清; 许嘉巍; 吕新苗

    2003-01-01

    The sandy land of the western part of Jilin Province is located in the ecotone ofsemi-humid and semi-arid area in the temperate zone of China. The sandy desertification has widelyspread in the region because of the vulnerable natural conditions and the unreasonable humanactivity; as a result of this, the precious land resources and the economic development in the areahave been seriously impacted. In this paper, the sandy land ecologic environment geographicinformation system is established based on the multi-spectral, multi-temporal Landsat TM images andfield investigation. The comprehensive indexes of sandy desertification extent assessment whichinclude vegetation degradation, wind erosion extent and soil depth are presented to classify the sandyland in western Jilin into three levels--slight, moderate and severe sandy desertification with thesupport of GIS platform. The results demonstrate that the sandy desertiffcation has been partlycontrolled in the past twenty years, except some small sites. However, this doesn't necessarily meanthat there is nothing for more concern. The two main causes of sandy desertification have not beeneliminated yet, one is its natural factor, especially the physical and chemical characters of sandy soiland dry climate; another is the immoderate economic activity of human being that has highlyaccelerated the sandy desertification process.

  15. The Storm Surge and Sub-Grid Inundation Modeling in New York City during Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Harry V. Wang

    2014-03-01

    Full Text Available Hurricane Sandy inflicted heavy damage in New York City and the New Jersey coast as the second costliest storm in history. A large-scale, unstructured grid storm tide model, Semi-implicit Eulerian Lagrangian Finite Element (SELFE, was used to hindcast water level variation during Hurricane Sandy in the mid-Atlantic portion of the U.S. East Coast. The model was forced by eight tidal constituents at the model’s open boundary, 1500 km away from the coast, and the wind and pressure fields from atmospheric model Regional Atmospheric Modeling System (RAMS provided by Weatherflow Inc. The comparisons of the modeled storm tide with the NOAA gauge stations from Montauk, NY, Long Island Sound, encompassing New York Harbor, Atlantic City, NJ, to Duck, NC, were in good agreement, with an overall root mean square error and relative error in the order of 15–20 cm and 5%–7%, respectively. Furthermore, using large-scale model outputs as the boundary conditions, a separate sub-grid model that incorporates LIDAR data for the major portion of the New York City was also set up to investigate the detailed inundation process. The model results compared favorably with USGS’ Hurricane Sandy Mapper database in terms of its timing, local inundation area, and the depth of the flooding water. The street-level inundation with water bypassing the city building was created and the maximum extent of horizontal inundation was calculated, which was within 30 m of the data-derived estimate by USGS.

  16. Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR.

    Directory of Open Access Journals (Sweden)

    Rishi Prasad

    Full Text Available Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L. production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1 N of the total input N (310 to 349 kg ha(-1 N. The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1 N and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn. The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.

  17. Effect of pH on bacteriophage transport through sandy soils

    Science.gov (United States)

    Kinoshita, Takashi; Bales, Roger C.; Maguire, Kimberley M.; Gerba, Charles P.

    1993-01-01

    Effects of pH and hydrophobicity on attachment and detachment of PRD-1 and MS-2 in three different sandy soils were investigated in a series of laboratory-column experiments. Concentrations of the lipid-containing phage PRD-1 decreased 3–4 orders of magnitude during passage through the 10–15-cm-long columns. Attachment of the lipid-containing phage PRD-1 was insensitive to pH and was apparently controlled by hydrophobic interactions in soil media. The less-hydrophobic phage MS-2 acted conservatively; it was not removed in the columns at pH's 5.7–8.0. The sticking efficiency (α) in a colloid-filtration model was between 0.1 and 1 for PRD-1, indicating a relatively high removal efficiency. Phage attachment was reversible, but detachment under steady-state conditions was slow. An increase in pH had a moderate effect on enhancing detachment. Still, these soils should continue to release phage to virus-free water for days to weeks following exposure to virus-containing water. In sandy soils with a mass-fraction organic carbon as low as a few hundredths of a percent, pH changes in the range 5.7–8.0 should have little effect on retention of more-hydrophobic virus (e.g., PRD-1), in that retardation will be dominated by hydrophobic effects. Sharp increases in pH should enhance detachment and transport of virus previously deposited on soil grains. A more hydrophilic virus (e.g., MS-2) will transport as a conservative tracer in low-carbon sandy soil.

  18. Road traffic and sandy playground influence on ambient pollutants in schools

    Science.gov (United States)

    Minguillón, M. C.; Rivas, I.; Moreno, T.; Alastuey, A.; Font, O.; Córdoba, P.; Álvarez-Pedrerol, M.; Sunyer, J.; Querol, X.

    2015-06-01

    Urban air pollution has a greater impact on children's health compared to adults. In the framework of the BREATHE (BRain dEvelopment and Air polluTion ultrafine particles in scHool childrEn) project, the present work studies the impact of road traffic and the presence of sandy playgrounds on the outdoor air quality around schools. Four schools were selected for intensive campaigns of one month. PM2.5 samples were collected daily from 8:00 to 20:00 and chemically analysed. Real time measurements of NOx, black carbon (BC), PM1, PM2.5 and PM10 concentrations were carried out. Sand samples from five school playgrounds were characterized. The results confirm the representativeness of the general BREATHE project campaigns (eight weekdays measurements at each of the 39 schools). NOx, BC and PMx concentrations were higher in the school located nearest to traffic in the city centre with the daily pattern reflecting the traffic rush hours. The NOx concentrations were found to decrease with distance to the main road. The road traffic influence on ambient pollutants was higher on weekdays than weekends. The PM10 concentrations at one of the schools were mainly driven by the influence of the sandy playground, with peaks up to 25, 57 and 12 times higher than night background concentrations during mid-morning break, lunch break and end of school day, respectively. The airborne mineral matter concentrations registered at this school further confirm this origin. Nevertheless the influence of the re-suspension from the sandy playground was very local and decreased drastically within a short distance. The possible impact of the use of the private car for children's commuting on the outdoor air quality of the schools cannot be quantitatively assessed due to the overlapping with the rush hour of the city.

  19. Virus and bacteria transport in a sandy aquifer, Cape Cod, MA

    Science.gov (United States)

    Bales, Roger C.; Li, Shimin; Maguire, Kimberly M.; Yahya, Moyasar T.; Gerba, Charles P.; Harvey, Ronald W.

    1995-01-01

    Transport of the bacteriophage PRD-1, bacteria, and latex microspheres was studied in a sandy aquifer under natural-gradient conditions. The field injection was carried out at the U.S. Geological Survey's Toxic Substances Hydrology research site on Cape Cod. The three colloids and a salt tracer (Br−) moved along the same path. There was significant attenuation of the phage, with PRD-1 peak concentrations less than 0.001 percent of Br− peaks 6 m from the source; but the low detection limit (one per ml) enabled tracking movement of the PRD-1 plume for 12 m downgradient over the 25-day experiment. Attenuation of phage was apparently due to retention on soil particles (adsorption). Attenuation of bacteria and microspheres was less, with peak concentrations 6 m from the source on the order of 10 and 0.4 percent of Br−, respectively. Injection of a high-pH pulse of water 20 days into the experiment resulted in significant remobilization of retained phage, demonstrating that attached phage remained viable, and that PRD-1 attachment to and detachment from the sandy soil particles was highly pH dependent. Phage behavior in this experiment, i.e. attenuation at pH 5.7 and rapid resuspension at pH 6–8, was consistent with that observed previously in laboratory column studies. Results illustrate that biocolloids travel in a fairly narrow plume in sandy (relatively homogeneous) media, with virus concentrations dropping below detection limit several meters away from the source; bacteria concentrations above detection limits can persist over longer distances.

  20. Estimation of Variability Characteristics of Regional Drought during 1964–2013 in Horqin Sandy Land, China

    Directory of Open Access Journals (Sweden)

    Yongfang Wang

    2016-11-01

    Full Text Available Drought has an important influence on the hydrological cycle, ecological system, industrial and agricultural production, and social life. Based on the different time scales of characteristics of drought variability, the standardized precipitation evapotranspiration index (SPEI, a multi-timescale index with consideration of evaporation, was used in this study to estimate the spatial and temporal variability characteristics of drought. Climatic data from 15 meteorological stations across Horqin Sandy Land during 1964–2013 were used to calculate the SPEI of 1, 3, 6, and 12 months. In order to examine the relationship between droughts and other variables, 10 extreme climate indices were calculated based on the daily precipitation and maximum/mean/minimum temperature data of 15 meteorological stations, and linkages between SPEI-12 and atmosphere indices were established using by the cross wavelet transform method. The results indicated that the climate of Horqin Sandy Land had a tendency towards drought conditions, which is particularly apparent from the year 2000 onwards. During the study period, drought events were frequent in the region. Mild drought occurred in a quarter of the month, with that of moderate, severe, and extreme drought accounting for 0.11, 0.05, and 0.02 of the total months. The spatial trend of multi-timescale drought revealed that there was an increase in the severity of drought throughout Horqin Sandy Land, among which the magnitude in southern parts was larger than that of northern parts. The results also showed that the short time scale drought negatively correlated with precipitation extremes and positively correlated with temperature extremes. Furthermore, the long time scale drought (SPEI-12 was associated with atmosphere indices. Significant resonance periods were found between El Nino southern oscillation (ENSO, the East Asian summer monsoon index (EASMI, and SPEI-12.

  1. Fit-for-purpose phosphorus management: do riparian buffers qualify in catchments with sandy soils?

    Science.gov (United States)

    Weaver, David; Summers, Robert

    2014-05-01

    Hillslope runoff and leaching studies, catchment-scale water quality measurements and P retention and release characteristics of stream bank and catchment soils were used to better understand reasons behind the reported ineffectiveness of riparian buffers for phosphorus (P) management in catchments with sandy soils from south-west Western Australia (WA). Catchment-scale water quality measurements of 60 % particulate P (PP) suggest that riparian buffers should improve water quality; however, runoff and leaching studies show 20 times more water and 2 to 3 orders of magnitude more P are transported through leaching than runoff processes. The ratio of filterable reactive P (FRP) to total P (TP) in surface runoff from the plots was 60 %, and when combined with leachate, 96 to 99 % of P lost from hillslopes was FRP, in contrast with 40 % measured as FRP at the large catchment scale. Measurements of the P retention and release characteristics of catchment soils (bank soil (bank soils suggest that catchment soils contain more P, are more P saturated and are significantly more likely to deliver FRP and TP in excess of water quality targets than stream bank soils. Stream bank soils are much more likely to retain P than contribute P to streams, and the in-stream mixing of FRP from the landscape with particulates from stream banks or stream beds is a potential mechanism to explain the change in P form from hillslopes (96 to 99 % FRP) to large catchments (40 % FRP). When considered in the context of previous work reporting that riparian buffers were ineffective for P management in this environment, these studies reinforce the notion that (1) riparian buffers are unlikely to provide fit-for-purpose P management in catchments with sandy soils, (2) most P delivered to streams in sandy soil catchments is FRP and travels via subsurface and leaching pathways and (3) large catchment-scale water quality measurements are not good indicators of hillslope P mobilisation and transport

  2. Human recreation alters behaviour profiles of non-breeding birds on open-coast sandy shores

    Science.gov (United States)

    Schlacher, Thomas A.; Nielsen, Tara; Weston, Michael A.

    2013-02-01

    Sandy beaches are primarily valued for their amenity and property values rather than for their ecological functions and properties. Some human usage of beaches potentially conflicts with the conservation and management of wildlife, such as beach-dwelling birds, on sandy shorelines. Because responses by birds to environmental change, including disturbance by humans, often involve behaviours that carry fitness costs, we quantify behaviour profiles of birds in relation to human occurrence along 200 km of sandy shoreline in Eastern Australia, including the large conservation area of Fraser Island. Disturbance to birds on these shores was considerable: 1) birds encountered motorized vehicles (cars, trucks, buses etc.) during 80% of focal bird observation bouts, 2) birds were flushed in over half (up to 86% in individual species) of all bouts, and 3) individuals spent, on average, one-third of their time on disturbance-related behaviours; this was particularly prevalent for Crested Terns (Thalasseus bergii) which were alert 42% of the time and spent 12% of their time escaping from human stimuli. Overall, this study demonstrated that motorized traffic is the prime agent of disturbance to birds on these beaches, resulting in frequent and time-consuming escape behaviours. These findings also emphasize that management of vehicle-based recreation on beaches needs to be re-aligned to meet conservation requirements in addition to providing leisure opportunities in National Parks and beyond; we identify some salient issue for this development: a) encouragement of social norms that promote environmentally benign beach use not involving motor vehicles, b) creation of spatial refuges for beach wildlife from traffic and other non-compatible uses, and c) investment in developing complementary management actions such as effective set-back distances.

  3. Immediate Impact of Hurricane Sandy on People Who Inject Drugs in New York City.

    Science.gov (United States)

    Pouget, Enrique R; Sandoval, Milagros; Nikolopoulos, Georgios K; Friedman, Samuel R

    2015-01-01

    Over the eight months following Hurricane Sandy, of October 2012, we interviewed 300 people who inject drugs in New York City. During the week after the storm, 28% rescued others or volunteered with aid groups; 60% experienced withdrawal; 27% shared drug injection or preparation equipment, or injected with people they normally would not inject with; 70% of those on opioid maintenance therapy could not obtain sufficient doses; and 43% of HIV-positive participants missed HIV medication doses. Although relatively brief, a hurricane can be viewed as a Big Event that can alter drug environments and behaviors, and may have lasting impact. The study's limitations are noted and future needed research is suggested.

  4. Enhancing evaluation of post-storm morphologic response using aerial orthoimagery from Hurricane Sandy

    Science.gov (United States)

    Smith, Jacquelyn Rose; Long, Joseph W.; Stockdon, Hilary F.; Birchler, Justin J.

    2015-01-01

    Improved identification of morphological responses to storms is necessary for developing and maintaining predictive models of coastal change. Morphological responses to Hurricane Sandy were measured using lidar and orthophotos taken before and after the storm. Changes to dune features measured from lidar were compared to the occurrence of overwash deposits measured using orthophotos. Thresholds on morphologic change (e.g. overwash volume and dune height change) were defined to optimize agreement between the classification of lidar and orthophoto-derived dune erosion and overwash. A linear regression showed that overwash volume can be calculated from orthophoto-derived overwash extent.

  5. Concomitants of perceived trust in hospital and medical services following Hurricane Sandy.

    Science.gov (United States)

    Ben-Ezra, Menachem; Goodwin, Robin; Palgi, Yuval; Kaniasty, Krzysztof; Crawford, Marsha Zibalese; Weinberger, Aviva; Hamama-Raz, Yaira

    2014-12-30

    The relationship between factors associated with perceived trust in hospital and medical services in the aftermath of a natural disaster is understudied. An online sample of 1000 people mainly from affected states was surveyed after Hurricane Sandy. Participants completed a survey which included disaster related questions and PTSD symptoms. Logistic regression revealed a significant association between perceived trust in hospital services to education, subjective well-being, being scared for the life of a loved one and perceived trust in emergency services. These findings may emphasis the positive association between maintaining active hospital services and mental health among the general population during crisis.

  6. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

    2012-01-01

    Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... and significantly decreased bulk density, with no effect on plant available water compared to the control. Fresh and dry fruit weights were significantly increased after compost addition. Plant height, leaf number, stem diameter, and total biomass did not significantly improve after compost addition. Spent mushroom...

  7. A modified criterion for wave-induced momentary liquefaction of sandy seabed

    Directory of Open Access Journals (Sweden)

    Wen-Gang Qi

    2015-01-01

    Full Text Available The assessment of the wave-induced soil liquefaction plays a key role in the geotechnical design for offshore foundations. The underlying shortcomings of the existing momentary liquefaction criteria are identified and clarified by mechanism analyses and the recent field observations. A modified criterion for the wave-induced momentary liquefaction of a sandy seabed is given to describe the vertical pore-pressure distributions. An improved approximation of the momentary liquefaction depth is further presented. Parametric study of the effects of the saturation degree of soils indicates that this modification is significant for the evaluation of wave-induced momentary liquefaction.

  8. Influence of manganese fertilizer on efficiency of grapes on sandy soils of the Chechen Republic

    Directory of Open Access Journals (Sweden)

    Batukaev A.A.

    2014-01-01

    Full Text Available As a result of the studies, there has been obtained new information about the manganese influence on productivity of grape plantations, on sandy soils of the Chechen Republic. Manganese fertilizing of 4 kg active ingredient per 1 ha, against the background of nitrogen 90 kg, phosphorus 90 kg and potassium 90 kg/ha, made it into a phase of grape sap flow, which contributes to higher yields, increase of the sugar content of the berries and a significant decrease in juice acidity, in comparison with other options.

  9. Relationships between water infiltration and oil spill migration in sandy soils

    Science.gov (United States)

    Kessler, Avner; Rubin, Hillel

    1987-06-01

    This article summarizes a study directed towards the prediction of oil spill migration in sandy soils. Such a prediction is needed for the design of remedial measures against soil and groundwater contamination. The geneal approach in this study is to convert available data concerning water infiltration into equivalent unknown data concerning oil spillage. This information is then fed into a numerical model by which the oil spill migration is simulated. Laboratory measurements including retention curve, hydraulic conductivity and infiltration rate, were made separately for water and kerosene in order to evaluate and confirm the suggested approach.

  10. Sustainable long-term intensive application of manure to sandy soils without phosphorus leaching

    DEFF Research Database (Denmark)

    Asomaning, Samuel K.; Abekoe, Mark K.; Dowuona, G.N.N.

    2015-01-01

    Long-term application of manure to sandy soils to ensure high crop productivity may lead to phosphorus (P) leaching, which, in turn, may deteriorate the quality of recipient waters because of eutrophication. The risk of P leaching depends on contents of aluminum (Al) and iron (Fe) oxides...... soils, whereas in the deepest soil layers the P contents in the cultivated and uncultivated soils were almost the same indicating very limited downward P transport despite long-term manure application. This was supported by comparable P concentrations in groundwater taken under cultivated...

  11. Three-dimensional distribution of plastic pellets in sandy beaches: shifting paradigms

    Science.gov (United States)

    Turra, Alexander; Manzano, Aruanã B.; Dias, Rodolfo Jasão S.; Mahiques, Michel M.; Barbosa, Lucas; Balthazar-Silva, Danilo; Moreira, Fabiana T.

    2014-03-01

    Plastic pellets are worldwide contaminants that accumulate in the ocean, especially in sandy beaches, where their historic standing-stock quantification relies on surface sediment samples. We demonstrated these particles present a three-dimensional instead of a simple along-across shore distribution, being found as deep as 2.0 m, with surface layers accounting for microplastics and sedimentary environments as a whole should be investigated. This poses criticism in the exactness of standing-stock records and demands urgent discussion of sampling protocols.

  12. Promoting Community Preparedness and Resilience: A Latino Immigrant Community-Driven Project Following Hurricane Sandy.

    Science.gov (United States)

    Cuervo, Isabel; Leopold, Les; Baron, Sherry

    2017-09-01

    As community residents and recovery workers, Latino immigrants play important roles after disasters, yet are rarely included in preparedness planning. A community-university-labor union partnership created a demonstration project after Hurricane Sandy to strengthen connections to disaster preparedness systems to increase community resilience among Latino immigrant communities in New York and New Jersey. Building ongoing ties that connect workers and community-based organizations with local disaster preparedness systems provided mutual benefits to disaster planners and local immigrant communities, and also had an impact on national disaster-related initiatives.

  13. Experimental study on subharmonic and ultraharmonic acoustic waves in water-saturated sandy sediment.

    Science.gov (United States)

    Kim, Byoung-Nam; Lee, Kang Il; Yoon, Suk Wang

    2007-04-01

    Experimental observations of the subharmonic and ultraharmonic acoustic waves in water-saturated sandy sediment are reported in this paper. Acoustic pressures of both nonlinear acoustic waves strongly depend on the driving acoustic pressure at a transducer. The first ultraharmonic wave reaches a saturation value as the driving acoustic pressure increases. The acoustic pressure levels of both nonlinear acoustic waves exhibit some fluctuations in comparison with that of the primary acoustic wave as the receiving distance of hydrophone increases in sediment. The subharmonic and the ultraharmonic phenomena in this study show close resemblance to those produced in bubbly water.

  14. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

    OpenAIRE

    Baille Wiebke; Jebeli Alireza; Schanz Tom

    2016-01-01

    In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains) during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand gra...

  15. Comments on“Sidewinding with Minimal Slip:Snake and Robot Ascent of Sandy Slopes”

    Institute of Scientific and Technical Information of China (English)

    LIU Jinguo; GAO Yang; WANG Yuechao; MA Shugen; LUO Yifan

    2015-01-01

    Marvi et al (Science, 2014, vol.346, p.224) concluded a sidewinder rattlesnake increases the body contact length with the sand when granular incline angle increases. They also claimed the same principle should work on robotic snake too. We have evidence to prove that this conclusion is only partial in describing the snake body-sand interaction. There should be three phases that fully represent the snake locomotion behaviors during ascent of sandy slopes, namely lifting, descending, and ceasing. The snake body-sand interaction during the descending and ceasing phases helps with the climbing while such interaction during the lifting phase in fact contributes resistance.

  16. Assessment of physical and chemical indicators of sandy soil quality for sustainable crop production

    Science.gov (United States)

    Lipiec, Jerzy; Usowicz, Boguslaw

    2017-04-01

    Sandy soils are used in agriculture in many regions of the world. The share of sandy soils in Poland is about 55%. The aim of this study was to assess spatial variability of soil physical and chemical properties affecting soil quality and crop yields in the scale of field (40 x 600 m) during three years of different weather conditions. The experimental field was located on the post glacial and acidified sandy deposits of low productivity (Szaniawy, Podlasie Region, Poland). Physical soil quality indicators included: content of sand, silt, clay and water, bulk density and those chemical: organic carbon, cation exchange capacity, acidity (pH). Measurements of the most soil properties were done at spring and summer each year in topsoil and subsoil layer in 150 points. Crop yields were evaluated in places close to measuring points of the soil properties. Basic statistics including mean, standard deviation, skewness, kurtosis minimal, maximal and correlations between the soil properties and crop yields were calculated. Analysis of spatial dependence and distribution for each property was performed using geostatistical methods. Mathematical functions were fitted to the experimentally derived semivariograms that were used for mapping the soil properties and crop yield by kriging. The results showed that the largest variations had clay content (CV 67%) and the lowest: sand content (5%). The crop yield was most negatively correlated with sand content and most positively with soil water content and cation exchange capacity. In general the exponential semivariogram models fairly good matched to empirical data. The range of semivariogram models of the measured indicators varied from 14 m to 250 m indicate high and moderate spatial variability. The values of the nugget-to-sill+nugget ratios showed that most of the soil properties and crop yields exhibited strong and moderate spatial dependency. The kriging maps allowed identification of low yielding sub-field areas that

  17. Depositional models of sandy debrites and turbidites of Palaeogene reservoir sands in deep-lacustrine environments, South China

    Science.gov (United States)

    Li, Y.; Chen, G.

    2013-12-01

    Two depositional models are proposed for deep-lacustrine petroleum reservior sands (Palaeogene) in the Fushan Sag, Beibuwan Basin, South China. This facies trend is used as a template for predicting the distribution of reservoir facies of the Fushan oilfield. Based on examination of 150m of conventional cores from 13 drilled wells, four depositional facies have been interpreted: (1) fine-grained massive sandstone with floating mudstone clasts and planar clast fabric (sandy debrite); (2) fine-grained sandstone and siltstone showing contorted bedding, sand injection, and ptygmatic folding (sandy slump), (3) fine-grained sandstone with thin layers of normal grading and flute casts (turbidite), and (4) mudstone with faint laminae (suspension fallout). Combined with multiple seismic attributes, two depositional models are characterized by (1) sublacustrine fan: thick turbidite units occur at the bottom of the western sag beneath a series of normal faults slope. (2) Thinner deposition of sandy debrites mainly distribute at the bottom of eastern sag far from sandy slump at the lake margin slope, which interpreted to be controlled by "two-step" flexure slope break. The transfer zone located in the centre area is confirmed to be the primary origin for such differential depositions. In our study area, sandy debrites constitute the producing petroleum reservoirs, but turbidites are non reservoirs. This dramatic understanding will well account for "eastern much more than western" distribution of proven petroleum reserves and be applicable to predicting reservoir distribution.

  18. Fire behavior in Mediterranean shrub species (Maquis)

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-19

    Nov 19, 2008 ... experimental fires were carried out in tall maquis fuels in Asar District, Antalya, southwestern Turkey. ... and loam and sandy loam of limestone origin. ... Then, using linear regression models, equations were generated for.

  19. Steam and air co-injection in removing residual TCE in unsaturated layered sandy porous media.

    Science.gov (United States)

    Peng, Sheng; Wang, Ning; Chen, Jiajun

    2013-10-01

    Steam and air co-injection is a promising technique for volatile and semi-volatile organic contaminant remediation in heterogeneous porous media. In this study, removal of trichloroethene (TCE) with steam-air co-injection was investigated through a series of 2D sandbox experiments with different layered sand structures, and through numerical simulations. The results show that a layered structure with coarse sand, in which steam and air convection are relatively rapid, resulted in a higher removal rate and a larger removal ratio than those observed in an experiment using finer sand; however, the difference was not significant, and the removal ratios from three experiments ranged from 85% to 94%. Slight downward movement of TCE was observed for Experiment 1 (TCE initially in a fine sand zone encased in a coarse sand), while no such movement was observed for Experiment 2 (TCE initially in two fine sand layers encased in a coarse sand) or 3 (TCE initially in a silty sand zone encased in a coarse sand). Simulations show accumulation of TCE at the interface of the layered sands, which indicates a capillary barrier effect in restraining the downward movement of TCE. This effect is illustrated further by a numerical experiment with homogeneous coarse sand, in which continuous downward TCE movement to the bottom of the sandbox was simulated. Another numerical experiment with higher water saturation was also conducted. The results illustrate a complicated influence of water saturation on TCE removal in a layered sand structure.

  20. One-dimensional Markov chain simulation of vertical change of soil texture in middle reaches of Heihe river, northwest China%一维马尔可夫链模拟黑河中游流域土壤质地垂向变异

    Institute of Scientific and Technical Information of China (English)

    李丹凤; 邵明安

    2013-01-01

    taken into a laboratory and having been wind-dried, the soil mechanical composition was measured using a Malvern Laser particle size analyzer. Then the vertical change of soil textural layers was analyzed, and a MC-LN (Markov chain-lognormal distribution) model was constructed to simulate the soil textural profiles. Results showed that there were seven soil textural types occurring in the study area, namely, sand, loamy sand, sandy loam, loam, clay loam, silty clay loam and silt clay, respectively. Compared with the non-occurrence of silty clay layers in the surface soil, another six types of textural layers all occurred in the surface soil of the study area, while sand layers occurred with a much higher probability than the others. The layer thickness of each textural type in the study area was characterized as a lognormal distribution, with relatively thick sand and silty clay loam layers, and relatively thin sandy loam, loam and clay layers. For a certain textural type, layers occurred beneath it were mainly the two types which adjoined it, especially the one which contained more fine particles. The uncertainty analysis of soil textural layer transitions indicated that the formation of loamy sand layers was much strongly dependent on the lower layers, whereas the clay loam layers had a key effect on the formation of the upper layers. Loamy sand and loam layers had a relative high probability to have sandy loam layers as upper layers, while silty clay loam layers had relative high probability to occur as upper layers of both clay loam and silty clay layers. None of the seven textural layers had the same combinations of upper and lower layers simultaneously. Markov characteristics and the stability of the vertical change of textural layers were verified byχ2 test using the TPMs of the entire samples, the subintervals and the sub-regions. A one-dimensional MC-LN model could quantitatively describe the vertical change of textural layers. The simulated TPM approached to