Sample records for sandy aquifer temporal

  1. Spatial and temporal small-scale variation in groundwater quality of a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Christensen, Thomas Højlund


    The groundwater quality of a shallow unconfined sandy aquifer has been characterized for pH, alkalinity, chloride, nitrate, sulfate, calcium, magnesium, sodium and potassium in terms of vertical and horizontal variations (350 groundwater samples). The test area is located within a farmland lot....... The geology of the area described on the basis of 31 sediment cores appears relatively homogeneous. Large vertical and horizontal variations were observed. The vertical variations are strongly affected by the deviating composition of the agricultural infiltration water. The horizontal variations show very...

  2. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

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


    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......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...

  3. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

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


    Distribution coe�cients (Kd) were measured for copper (Cu) and zinc (Zn) in laboratory batch experiments for 17 sandy aquifer materials at environmentally relevant solute concentrations (Cu: 5±300 mg/l, Zn: 20±3100 mg/l). The Kd values ranged two to three orders of magnitude (Cu: 70±10,800 l/ kg...

  4. Field experiment on multicomponent ion exchange in a sandy aquifer

    International Nuclear Information System (INIS)

    Bjerg, P.L.; Christensen, T.H.


    A field experiment is performed in a sandy aquifer in order to study ion exchange processes and multicomponent solute transport modeling. An injection of groundwater spiked with sodium and potassium chloride was performed over a continuous period of 37 days. The plume is monitored by sampling 350 filters in a spatial grid. The sampling aims at establishing compound (calcium, magnesium, potassium, sodium, chloride) breakthrough curves at various filters 15 to 100 m from the point of injection and areal distribution maps at various cross sections from 0 to 200 m from the point of injection. A three-dimensional multicomponent solute transport model will be used to model the field experiments. The chemical model includes cation exchange, precipitation, dissolution, complexation, ionic strength and the carbonate system. Preliminary results from plume monitoring show that the plume migration is relatively well controlled considering the scale and conditions of the experiment. The transverse dispersion is small causing less dilution than expected. The ion exchange processes have an important influence on the plume composition. Retardation of the injected ions is substantial, especially for potassium. Calcium exhibits a substantial peak following chloride due to release from the ion exchange sites on the sediment. (Author) (8 refs., 5 figs., tab.)

  5. 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


    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 fin...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium.......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...

  6. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund


    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation......, to be in the range of 0.3–0.5 m compared with a value of 0.42 m obtained in one of the tracer tests performed....

  7. Large-Scale Experiments in a Sandy Aquifer in Denmark

    DEFF Research Database (Denmark)

    Jensen, Karsten Høgh; Bitsch, Karen Bue; Bjerg, Poul Løgstrup


    vertical directions was very small. The horizontal transport parameters of the advection-dispersion equation were investigated by applying an optimization model to observed breakthrough curves of tritium representing depth averaged concentrations. No clear trend in dispersion parameters with travel...... distance for distances between 50 and 200 m could be found, suggesting that the asymptotic stage was reached within a short distance from the point of injection. A three-dimensional numerical model for flow and transport was applied to the aquifer in order to quantify the dispersivity parameters more...

  8. Uranium partitioning under acidic conditions in a sandy soil aquifer

    International Nuclear Information System (INIS)

    Johnson, W.H.; Serkiz, S.M.; Johnson, L.M.


    The partitioning of uranium in an aquifer down gradient of two large mixed waste sites was examined with respect to the solution and soil chemistry (e.g., pH redox potential and contaminant concentration) and aqueous-phase chemical speciation. This involved generation of field-derived, batch sorption, and reactive mineral surface sorption data. Field-derived distribution coefficients for uranium at these waste sites were found to vary between 0.40 and 15,000. Based on thermodynamic speciation modeling and a comparison of field and laboratory data, gibbsite is a potential reactive mineral surface present in modified soils at the sites. Uranium partitioning data are presented from field samples and laboratory studies of background soil and the mineral surface gibbsite. Mechanistic and empirical sorption models fit to the field-derived uranium partitioning data show an improvement of over two orders of magnitude, as measured by the normalized sum of errors squared, when compared with the single K d model used in previous risk work. Models fit to batch sorption data provided a better fit of sorbed uranium than do models fit to the field-derived data

  9. Time scales of DNAPL migration in sandy aquifers examined via numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard, J.I.; Pang, T.; Kueper, B.H. [University of Edinburgh, Edinburgh (United Kingdom). Inst. of Infrastructure & Environmental


    The time required for dense nonaqueous phase liquid (DNAPL) to cease migrating following release to the subsurface is a valuable component of a site conceptual model. This study uses numerical simulation to investigate the migration of six different DNAPLs in sandy aquifers. The most influential parameters governing migration cessation time are the density and viscosity of the DNAPL and the mean hydraulic conductivity of the aquifer. Releases of between 1 and 40 drums of chlorinated solvent DNAPLs, characterized by relatively high density and low viscosity, require on the order of months to a few years to cease migrating in a heterogeneous medium sand aquifer having an average hydraulic conductivity of 7.4 x 10{sup -3} cm/s. In contrast to this, the release of 20 drums of coal tar {rho}{sub D} = 1061 kg/m{sup 3}, {mu}{sub D} = 0.161 Pa(.)s) requires more than 100 years to cease migrating in the same aquifer. Altering the mean hydraulic conductivity of the aquifer results in a proportional change in cessation times. Parameters that exhibit relatively little influence on migration time scales are the DNAPL-water interfacial tension, release volume, source capillary pressure, mean aquifer porosity, and ambient ground water hydraulic gradient. This study also demonstrates that low-density DNAPLs (e.g., coal tar) give rise to greater amounts of lateral spreading and greater amounts of pooling on capillary barriers than high-density DNAPLs such as trichloroethylene or tetrachloroethylene.

  10. Predicting the denitrification capacity of sandy aquifers from shorter-term incubation experiments and sediment properties

    Directory of Open Access Journals (Sweden)

    W. Eschenbach


    Full Text Available Knowledge about the spatial variability of denitrification rates and the lifetime of denitrification in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, regression models were derived to estimate the measured cumulative denitrification of aquifer sediments after one year of incubation from initial denitrification rates and several sediment parameters, namely total sulphur, total organic carbon, extractable sulphate, extractable dissolved organic carbon, hot water soluble organic carbon and potassium permanganate labile organic carbon.

    For this purpose, we incubated aquifer material from two sandy Pleistocene aquifers in Northern Germany under anaerobic conditions in the laboratory using the 15N tracer technique. The measured amount of denitrification ranged from 0.19 to 56.2 mg N kg−1 yr−1. The laboratory incubations exhibited high differences between non-sulphidic and sulphidic aquifer material in both aquifers with respect to all investigated sediment parameters. Denitrification rates and the estimated lifetime of denitrification were higher in the sulphidic samples. For these samples, the cumulative denitrification measured during one year of incubation (Dcum(365 exhibited distinct linear regressions with the stock of reduced compounds in the investigated aquifer samples. Dcum(365 was predictable from sediment variables within a range of uncertainty of 0.5 to 2 (calculated Dcum(365/measured Dcum(365 for aquifer material with a Dcum(365 > 20 mg N kg−1 yr−1. Predictions were poor for samples with lower Dcum(365, such as samples from the NO3 bearing groundwater zone, which includes the non-sulphidic samples, from the upper part of both aquifers where denitrification is not sufficient to

  11. Vertical small scale variations of sorption and mineralization of three herbicides in subsurface limestone and sandy aquifer

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Mouvet, C.; Albrechtsen, Hans-Jørgen


    , France. From two intact core drills, four heterogenic limestone sections were collected from 4.50-26.40 m below surface (mbs) and divided into 12 sub-samples of 8-25 cm length, and one sandy aquifer section from 19.20-19.53 m depth divided into 7 sub-samples of 4-5 cm length. In the sandy aquifer section...... showed that a 30 cm active layer with the measured sorption and mineralization values hardly impacted the fate of the investigated herbicides, whereas a total thickness of layers of 1 m would substantially increase natural attenuation....

  12. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study

    NARCIS (Netherlands)

    Regelink, I.C.; Temminghoff, E.J.M.


    Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At

  13. Fate of the herbicide glufosinate-ammonium in the sandy, low-organic-carbon aquifer at CFB Borden, Ontario, Canada (United States)

    Allen-King, Richelle M.; Butler, Barbara J.; Reichert, Barbara


    The herbicide glufosinate-ammonium was persistent in aerobic sandy aquifer material in laboratory batch and field in situ microcosms when added at concentrations of 50-400 μg L -1. In contrast, the compound is biotransformed relatively quickly in surface soil. Glufosinate transformation and metabolite (3-methylphosphinyl-propionic acid) production in carbonamended laboratory microcosms demonstrated that the aquifer system was carbon-limited with respect to glufosinate transformation. Microbiological test showed that flufosinateammonium and sodium-glufosinate was be used as a nitrogen source, in the presence of sufficient carbon. Glufosinate was not used by the native microorganisms as a source of phosphorus, nor metabolized as a sole carbon and energy source. Ammonium appeared to be preferred over glufosinate as a nitrogen source. When representative microbial strains isolated from the Borden aquifer were tested, most were glufosinate-ammonium tolerant. Complete inhibition of some isolates was demonstrated only at very high concentrations of 2-4 g L -1. The research suggests that in an aquifer with a relatively low clay content and little labile organic carbon, such as the sandy aquifer at the field site, glufosinate will be persistent and transport will be essentially unretarded. The availability of alternative nitrogen sources was also indicated as a parameter that can affect persistence.

  14. Stability Behavior and Thermodynamic States of Iron and Manganese in Sandy Soil Aquifer, Manukan Island, Malaysia

    International Nuclear Information System (INIS)

    Lin, Chin Yik; Abdullah, Mohd. Harun; Musta, Baba; Praveena, Sarva Mangala; Aris, Ahmad Zaharin


    A total of 20 soil samples were collected from 10 boreholes constructed in the low lying area, which included ancillary samples taken from the high elevation area. Redox processes were investigated in the soil as well as groundwater in the shallow groundwater aquifer of Manukan Island, Sabah, Malaysia. Groundwater samples (n = 10) from each boreholes were also collected in the low lying area to understand the concentrations and behaviors of Fe and Mn in the dissolved state. This study strives to obtain a general understanding of the stability behaviors on Fe and Mn at the upper unsaturated and the lower-saturated soil horizons in the low lying area of Manukan Island as these elements usually play a major role in the redox chemistry of the shallow groundwater. Thermodynamic calculations using PHREEQC showed that the groundwater samples in the study area are oversaturated with respect to goethite, hematite, Fe(OH) 3 and undersaturated with respect to manganite and pyrochroite. Low concentrations of Fe and Mn in the groundwater might be probably due to the lack of minerals of iron and manganese oxides, which exist in the sandy aquifer. In fact, high organic matters that present in the unsaturated horizon are believed to be responsible for the high Mn content in the soil. It was observed that the soil samples collected from high elevation area (BK) comprises considerable amount of Fe in both unsaturated (6675.87 mg/kg) and saturated horizons (31440.49 mg/kg) compared to the low Fe content in the low lying area. Based on the stability diagram, the groundwater composition lies within the stability field for Mn 2+ and Fe 2+ under suboxic condition and very close to the FeS/Fe 2+ stability boundary. This study also shows that both pH and Eh values comprise a strong negative value thus suggesting that the redox potential is inversely dependent on the changes of pH.

  15. The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers

    KAUST Repository

    Satyawali, Yamini


    Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy metals in soil and groundwater. This study reports the fate of Zn and Cd in sandy aquifers under a variety of plausible in-situ redox conditions that were induced by introduction of carbon and various electron acceptors in column experiments. Up to 100% Zn and Cd removal (from the liquid phase) was observed in all the four columns, however the mechanisms were different. Metal removal in column K1 (containing sulphate), was attributed to biological sulphate reduction and subsequent metal precipitation (as sulphides). In the presence of both nitrate and sulphate (K2), the former dominated the process, precipitating the heavy metals as hydroxides and/or carbonates. In the presence of sulphate, nitrate and supplemental iron (Fe(OH)3) (K3), metal removal was also due to precipitation as hydroxides and/or carbonates. In abiotic column, K4, (with supplemental iron (Fe(OH)3), but no nitrate), cation exchange with soil led to metal removal. The results obtained were modeled using the reactive transport model PHREEQC-2 to elucidate governing processes and to evaluate scenarios of organic carbon, sulphate and nitrate inputs. © 2010 Elsevier B.V.

  16. A natural gradient dispersion test in a sandy aquifer using tritium as tracer

    International Nuclear Information System (INIS)

    Bitsch, K.; Jensen, K.H.


    A large-scale natural gradient dispersion test was carried out in a sandy aquifer in the western part of Denmark using tritium as a tracer. A slug of tritium (4.66 x 10 9 Bq H 3 ) was injected, and the transport and dispersion behaviour of the plume were examined by water sampling in a dense three-dimensional network of observation piezometers. Transport parameters were determined by applying an optimization model to the observed breakthrough curves at various locations in the zone traversed by the tracer. The tracer plume migrated with a rather constant velocity of 0.7 m/day. A pronounced spreading was observed in the longitudinal direction while the spreading in the transverse horizontal and transverse vertical directions was very small. The asymptotic value for the dispersivity was apparently achieved within the first 50 m, reaching a value of 0.46 m, while the transverse dispersivities were estimated to be 0.02 m and 0.001 m in the horizontal and vertical directions, respectively. (Author) (33 refs., 8 figs., tab.)

  17. Vertical small scale variations of sorption and mineralization of three herbicides in subsurface limestone and sandy aquifer (United States)

    Janniche, G. S.; Mouvet, C.; Albrechtsen, H.-J.


    Vertical variation in sorption and mineralization potential of mecoprop (MCPP), isoproturon and acetochlor were investigated at low concentrations (μg-range) at the cm-scale in unsaturated sub-surface limestone samples and saturated sandy aquifer samples from an agricultural catchment in Brévilles, France. From two intact core drills, four heterogenic limestone sections were collected from 4.50 to 26.40 m below surface (mbs) and divided into 12 sub-samples of 8-25 cm length, and one sandy aquifer section from 19.20 to 19.53 m depth divided into 7 sub-samples of 4-5 cm length. In the sandy aquifer section acetochlor and isoproturon sorption increased substantially with depth; in average 78% (acetochlor) and 61% (isoproturon) per 5 cm. Also the number of acetochlor and isoproturon degraders (most-probable-number) was higher in the bottom half of the aquifer section (93-> 16 000/g) than in the upper half (4-71/g). One 50 cm long limestone section with a distinct shift in color showed a clear shift in mineralization, number of degraders and sorption: In the two brown, uppermost samples, up to 31% mecoprop and up to 9% isoproturon was mineralized during 231 days, the numbers of mecoprop and isoproturon degraders were 1300 to > 16 000/g, and the sorption of both isoproturon and acetochlor was more than three times higher, compared to the two deeper, grayish samples just below where mineralization (≤ 4%) and numbers of degraders (1-520/g) were low for all three herbicides. In both unsaturated limestone and sandy aquifer, variations and even distinct shifts in both mineralization, number of specific degraders and sorption were seen within just 4-15 cm of vertical distance. A simple conceptual model of herbicides leaching to groundwater through a 10 m unsaturated limestone was established, and calculations showed that a 30 cm active layer with the measured sorption and mineralization values hardly impacted the fate of the investigated herbicides, whereas a total

  18. Monitoring the evolution and migration of a methane gas plume in an unconfined sandy aquifer using time-lapse GPR and ERT. (United States)

    Steelman, Colby M; Klazinga, Dylan R; Cahill, Aaron G; Endres, Anthony L; Parker, Beth L


    Fugitive methane (CH 4 ) leakage associated with conventional and unconventional petroleum development (e.g., shale gas) may pose significant risks to shallow groundwater. While the potential threat of stray (CH 4 ) gas in aquifers has been acknowledged, few studies have examined the nature of its migration and fate in a shallow groundwater flow system. This study examines the geophysical responses observed from surface during a 72day field-scale simulated CH 4 leak in an unconfined sandy aquifer at Canadian Forces Base Borden, Canada, to better understand the transient behaviour of fugitive CH 4 gas in the subsurface. Time-lapse ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) were used to monitor the distribution and migration of the gas-phase and assess any impacts to groundwater hydrochemistry. Geophysical measurements captured the transient formation of a CH 4 gas plume emanating from the injector, which was accompanied by an increase in total dissolved gas pressure (P TDG ). Subsequent reductions in P TDG were accompanied by reduced bulk resistivity around the injector along with an increase in the GPR reflectivity along horizontal bedding reflectors farther downgradient. Repeat temporal GPR reflection profiling identified three events with major peaks in reflectivity, interpreted to represent episodic lateral CH 4 gas release events into the aquifer. Here, a gradual increase in P TDG near the injector caused a sudden lateral breakthrough of gas in the direction of groundwater flow, causing free-phase CH 4 to migrate much farther than anticipated based on groundwater advection. CH 4 accumulated along subtle permeability boundaries demarcated by grain-scale bedding within the aquifer characteristic of numerous Borden-aquifer multi-phase flow experiments. Diminishing reflectivity over a period of days to weeks suggests buoyancy-driven migration to the vadose zone and/or CH 4 dissolution into groundwater. Lateral and vertical CH 4

  19. Degradation of the Pesticides Mecoprop and Atrazine in Unpolluted Sandy Aquifers

    DEFF Research Database (Denmark)

    Klint, Mikala; Arvin, Erik; Jensen, Bjørn K.


    The potential for biodegradation of the pesticides mecoprop ((+/-)-2-(4-chloro-2-methyl-phenoxy)propionic acid) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in an aerobic aquifer was investigated in laboratory batch experiments. The experiments were performed with groundwater...... the aquifer. Atrazine was not degraded during an incubation period of 539 d in groundwater and 174 d in suspensions of groundwater and aquifer sediment. The addition of nutrients, primary substrates (acetate and naphthalene), and a pH or temperature increase had not effect on the recalcitrance of atrazine....

  20. Model Simulations of a Field Experiment on Cation Exchange-affected Multicomponent Solute Transport in a Sandy Aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Ammentorp, Hans Christian; Christensen, Thomas Højlund


    A large-scale and long-term field experiment on cation exchange in a sandy aquifer has been modelled by a three-dimensional geochemical transport model. The geochemical model includes cation-exchange processes using a Gaines-Thomas expression, the closed carbonate system and the effects of ionic...... by batch experiments and by the composition of the cations on the exchange complex. Potassium showed a non-ideal exchange behaviour with K&z.sbnd;Ca selectivity coefficients indicating dependency on equivalent fraction and K+ concentration in the aqueous phase. The model simulations over a distance of 35 m...... and a period of 250 days described accurately the observed attenuation of Na and the expelled amounts of Ca and Mg. Also, model predictions of plateau zones, formed by interaction with the background groundwater, in general agreed satisfactorily with the observations. Transport of K was simulated over a period...

  1. Extent and severity of groundwater contamination based on hydrochemistry mechanism of sandy tropical coastal aquifer. (United States)

    Isa, Noorain Mohd; Aris, Ahmad Zaharin; Sulaiman, Wan Nor Azmin Wan


    Small islands are susceptible to anthropogenic and natural activities, especially in respect of their freshwater supply. The freshwater supply in small islands may be threatened by the encroachment of seawater into freshwater aquifers, usually caused by over pumping. This study focused on the hydrochemistry of the Kapas Island aquifer, which controls the groundwater composition. Groundwater samples were taken from six constructed boreholes for the analysis and measurement of its in-situ and major ions. The experimental results show a positive and significant correlation between Na-Cl (r=0.907; paquifer bedrock. About 76% of collected data (n=108) were found to be in the dissolution process of carbonate minerals. Moreover, the correlation between total CEC and Ca shows a positive and strong relationship (r=0.995; pchemical composition. The output of this research explains the chemical mechanism attributed to the groundwater condition of the Kapas Island aquifer. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Effect of transient wave forcing on the behavior of arsenic in a sandy nearshore aquifer (United States)

    Rakhimbekova, S.; O'Carroll, D. M.; Robinson, C. E.


    Waves cause large quantities of coastal water to recirculate across the groundwater-coastal water interface in addition to inducing complex groundwater flows in the nearshore aquifer. Due to the distinct chemical composition of recirculating coastal water compared with discharging terrestrial groundwater, wave-induced recirculations and flows can alter geochemical gradients in the nearshore aquifer which may subsequently affect the mobilization and transport of reactive pollutants (e.g., arsenic). The impact of seasonal geochemical and hydrological variability on the occurrence and mobility of arsenic near the groundwater-surface water interface has been shown previously in riverine settings, however, the impact of high frequency geochemical variations (e.g., varying wave conditions) on arsenic mobility in groundwater-surface water environments is unclear. The objective of the study was to assess the impact of intensified wave conditions on the behavior of arsenic in a nearshore aquifer to determine the factors regulating its mobility and transport to receiving coastal waters. Field investigations were conducted at a permeable beach on the Great Lakes during a period of intensified wave conditions (wave event). High spatial resolution pore water sampling captured the geochemical conditions in the nearshore aquifer prior to the wave event, immediately after the wave event and over a recovery period of 3 weeks following the wave event. Shifts in pH and redox potential (ORP) gradients in response to varying wave conditions caused shifts in the iron and arsenic distributions in the aquifer. Sediment analysis was combined with the pore water distributions to assess the release of sediment-bound arsenic in response to the varying wave conditions. Insight into the effect of transient forcing on arsenic mobility and transport in groundwater-surface water environments is important for evaluating the potential risks associated with this toxic metalloid. The findings of this

  3. Method of forecasting pollutant transfer in an aquifer initial results obtained in a sandy medium (Barp site, Gironde)

    International Nuclear Information System (INIS)

    Madoz-Escande, C.; Peyrus, J.-C.


    Hydrogeological studies are undertaken in the context of the radiological safety of nuclear plants to forecast consequences of accidental releases of radioactive pollutants into an aquifer (transfer time, concentration at points of emergence). This quantitative forecast is obtained with the aid of a mathematical model with sequential emission. This requires a knowledge of the physical parameters of the aquifer and of the behavior of the pollutant in relation to the water-bearing medium. The physical parameters of a saturated porous medium are presented with the aid of radioactive tracer tests on a model and also in the field. The initial results obtained in a sandy medium are presented. In view of the difficulty of extrapolating to field conditions the conclusions of tests on models, it was necessary to set up a mobile laboratory with which in situ studies could be undertaken. The behavior of the pollutant in relation to the water-bearing medium is the subject of preliminary laboratory research on the laws of adsorption under different pH and temperature conditions. The numerical results obtained call for confirmation in the field. A description is given of a method which should enable the distribution coefficients to be evaluated in situ

  4. Isotopic and microbiological signatures of pyrite-driven denitrification in a sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Bostick, B.; Passier, H.F.; Böttcher, M.E.; Omoregie, E.O.; Lloyd, J.R.; Polya, D.A.; Van Cappellen, P.


    Denitrificationdriven by pyrite oxidation can play a major role in the removal of nitrate from groundwater systems. As yet, limited information is available on the interactions between the micro-organisms and aqueous and mineral phases in aquifers where pyrite oxidation is occurring. In this study,

  5. Isotopic and microbiological signatures of pyrite-driven denitrification in a sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.C.; Slomp, C.P.; Broers, H.P.; Bostick, B.; Passier, H.F.; Böttcher, M.E.; Omoregie, E.O.; Lloyd, J.R.; Polya, D.A.; Cappellen, P. van


    Denitrification driven by pyrite oxidation can play a major role in the removal of nitrate from groundwater systems. As yet, limited information is available on the interactions between the micro-organisms and aqueous and mineral phases in aquifers where pyrite oxidation is occurring. In this study,

  6. Understanding the fate of sanitation-related nutrients in a shallow sandy aquifer below an urban slum area (United States)

    Nyenje, P. M.; Havik, J. C. N.; Foppen, J. W.; Muwanga, A.; Kulabako, R.


    We hypothesized that wastewater leaching from on-site sanitation systems to alluvial aquifers underlying informal settlements (or slums) may end up contributing to high nutrient loads to surface water upon groundwater exfiltration. Hence, we conducted a hydro-geochemical study in a shallow sandy aquifer in Bwaise III parish, an urban slum area in Kampala, Uganda, to assess the geochemical processes controlling the transport and fate of dissolved nutrients (NO3, NH4 and PO4) released from on-site sanitation systems to groundwater. Groundwater was collected from 26 observation wells. The samples were analyzed for major ions (Ca, Mg, Na, Mg, Fe, Mn, Cl and SO4) and nutrients (o-PO4, NO3 and NH4). Data was also collected on soil characteristics, aquifer conductivity and hydraulic heads. Geochemical modeling using PHREEQC was used to determine the level of o-PO4 control by mineral solubility and sorption. Groundwater below the slum area was anoxic and had near neutral pH values, high values of EC (average of 1619 μS/cm) and high concentrations of Cl (3.2 mmol/L), HCO3 (11 mmol/L) and nutrients indicating the influence from wastewater leachates especially from pit latrines. Nutrients were predominantly present as NH4 (1-3 mmol/L; average of 2.23 mmol/L). The concentrations of NO3 and o-PO4 were, however, low: average of 0.2 mmol/L and 6 μmol/L respectively. We observed a contaminant plume along the direction of groundwater flow (NE-SW) characterized by decreasing values of EC and Cl, and distinct redox zones. The redox zones transited from NO3-reducing in upper flow areas to Fe-reducing in the lower flow areas. Consequently, the concentrations of NO3 decreased downgradient of the flow path due to denitrification. Ammonium leached directly into the alluvial aquifer was also partially removed because the measured concentrations were less than the potential input from pit latrines (3.2 mmol/L). We attributed this removal (about 30%) to anaerobic ammonium oxidation

  7. Enrichment of Geobacter species in response to stimulation of Fe(III) reduction in sandy aquifer sediments (United States)

    Snoeyenbos-West, O.L.; Nevin, K.P.; Anderson, R.T.; Lovely, D.R.


    Engineered stimulation of Fe(III) has been proposed as a strategy to enhance the immobilization of radioactive and toxic metals in metal-contaminated subsurface environments. Therefore, laboratory and field studies were conducted to determine which microbial populations would respond to stimulation of Fe(III) reduction in the sediments of sandy aquifers. In laboratory studies, the addition of either various organic electron donors or electron shuttle compounds stimulated Fe(III) reduction and resulted in Geobacter sequences becoming important constituents of the Bacterial 16S rDNA sequences that could be detected with PCR amplification and denaturing gradient gel electrophoresis (DGGE). Quantification of Geobacteraceae sequences with a PCR most-probable-number technique indicated that the extent to which numbers of Geobacter increased was related to the degree of stimulation of Fe(III) reduction. Geothrix species were also enriched in some instances, but were orders of magnitude less numerous than Geobacter species. Shewanella species were not detected, even when organic compounds known to be electron donors for Shewanella species were used to stimulate Fe(III) reduction in the sediments. Geobacter species were also enriched in two field experiments in which Fe(III) reduction was stimulated with the addition of benzoate or aromatic hydrocarbons. The apparent growth of Geobacter species concurrent with increased Fe(III) reduction suggests that Geobacter species were responsible for much of the Fe(III) reduction in all of the stimulation approaches evaluated in three geographically distinct aquifers. Therefore, strategies for subsurface remediation that involve enhancing the activity of indigenous Fe(III)-reducing populations in aquifers should consider the physiological properties of Geobacter species in their treatment design.

  8. A shallow geothermal experiment in a sandy aquifer monitored using electric resistivity tomography


    Hermans, Thomas; Vandenbohede, Alexander; Lebbe, Luc; Nguyen, Frédéric


    Groundwater resources are increasingly used around the world for geothermal exploitation systems. To monitor such systems and to estimate their governing parameters, we rely mainly on borehole observations of the temperature field at a few locations. Bulk electrical resistivity variations can bring important information on temperature changes in aquifers. In this paper, we demonstrate the ability of surface electrical resistivity tomography to monitor spatially temperature variations in a san...

  9. Evaluation of bromide mass discharge in a sandy aquifer at Vandenberg AFB, CA (United States)

    Mackay, D. M.; Rasa, E.; Einarson, M.; Kaiser, P.; Chakraborty, I.; Scow, K. M.


    Side-by-side experiments were conducted by UC Davis research team at a former fuel station at Vandenberg Air Force Base (AFB) to evaluate the rate of transformation of methyl tert-butyl ether (MTBE) to tert-butyl alcohol (TBA) impacted by ethanol and to investigate evidence of TBA degradation under sulfate reducing conditions. On one side we injected groundwater amended with ethanol and MTBE. In the other lane we injected groundwater amended with TBA. On both sides, injected ground water was spiked with bromide tracer to provide estimates of groundwater flow direction variations, flow velocity, dispersion, and mobile mass loss resulting from diffusive sequestration into aquitards. 162 monitoring wells were aligned into seven transects located downgradient of the injection wells. The mass discharge approach was used to evaluate the natural attenuation of the injected constituents. In this talk we will focus on calculations of mass discharge of the bromide tracer at each of the seven monitoring well transects. The amount of bromide mass discharged through each transect was calculated for any sampling time using field measurements of break through curves. Cumulative mass discharges were estimated and, by iteration based on mass balance, the flow properties of the aquifer were estimated. The calibration process resulted in subtle but quantitatively important changes in our assumptions regarding key physical properties of the aquifer (thickness, porosity) which could be only approximately estimated by standard methods (coring, CPT, etc.). On the basis of this calibration, a more robust approach was devised for evaluating the source and fate of TBA in the aquifer.

  10. Evolution of Uranium Isotopic Compositions of the Groundwater and Rock in a Sandy-Clayey Aquifer

    Directory of Open Access Journals (Sweden)

    Alexander I. Malov


    Full Text Available Uranium isotopes have been used as mechanistic or time scale tracers of natural processes. This paper describes the occurrence and redistribution of U in the Vendian aquifer of a paleo-valley in NW Russia. Forty-four rock samples were collected from nine boreholes with depths up to 160 m, and 25 groundwater samples were collected from 23 boreholes with depths up to 300 m. The U, Fe concentration, and 234U/238U activity ratio were determined in the samples. Estimations were made of the 14C and 234U-238U residence time of groundwater in the aquifer. It has been established that the processes of chemical weathering of Vendian deposits led to the formation of a strong oxidation zone, developed above 250 m.b.s.l. The inverse correlation between the concentrations of uranium and iron is a result of removal of U from paleo-valley slopes in oxidizing conditions, accumulation of U at the bottom of the paleo-valley in reducing conditions, and accumulation of Fe on the slopes and removal from the bottom of the paleo-valley. Almost all U on the slopes has been replaced by a newly formed hydrogenic U with a higher 234U/238U activity ratio. After, dissolution and desorption of hydrogenic U occurred from the slopes during periods with no glaciations and marine transgressions. Elevated concentrations of U are preserved in reduced lenses at the paleo-valley bottom. In these areas, the most dangerous aspect is the flow of groundwater from the underlying horizons, since during the operation of water supply wells it can lead to the creation of local zones of oxidizing conditions in the perforated screens zone and the transition of uranium into solution. For groundwater under oxidizing conditions, an increase in the concentration of uranium is characteristic of an increase in the residence time (age of water in the aquifer. Also, the 234U/238U activity ratio increases with increasing radioactivity of groundwater. Therefore, the most rational approach is to use

  11. Energy performance and thermal impact of a Borehole Heat Exchanger in a sandy aquifer: Influence of the groundwater velocity

    International Nuclear Information System (INIS)

    Angelotti, A.; Alberti, L.; La Licata, I.; Antelmi, M.


    Highlights: • A numerical model of a Borehole Heat Exchanger with groundwater flow is created. • The model is carefully validated against analytical solutions. • The mutual influence of the BHE heat rate and the ground temperature field is shown. • For 10 −1 ⩽ Pe ⩽ 1 the heat rate increase with respect to null velocity is 11–105%. • Large groundwater velocities reduce the benefits of operating in both seasons. - Abstract: In a saturated soil, the groundwater flow affects both the energy performance and the thermal impact on the surrounding soil of Borehole Heat Exchangers linked to Ground-Source Heat Pumps. In this paper a numerical model in MODFLOW/MT3DMS of a single U-pipe in a sandy aquifer is proposed in order to investigate the two issues in a coupled approach. After validating the model, the typical yearly operation of a Borehole Heat Exchanger extracting and injecting heat into the ground is simulated. For 0.1 ⩽ Pe ⩽ 1 cold and warm plumes develop and the heat rate increases non linearly from 11% to 105%

  12. Migration of uranium in the presence of clay colloids in a sandy aquifer

    International Nuclear Information System (INIS)

    Le Cointe, P.; Grambow, B.; Piscitelli, A.; Montavon, G.; Van der Lee, J.; Giffaut, E.; Schneider, V.


    Document available in extended abstract form only. In France, low and medium level radioactive waste of short period (nuclides with a half-life less than 31 years and an activity ranging from 100 to 1,000,000 Bq/g) is stored in concrete constructions on a surface site in Soulaines-Dhuys (Aube). The site was chosen for its simple geology: it entirely lays on an aquifer formation, the Upper Aptian sands, above a Lower Aptian impermeable clay formation. The site is surrounded by the Noues d'Amance stream, which serves as the single outlet of the groundwater on the site. The objective of this study is to improve knowledge of radionuclides migration in the aquifer formation to improve safety, using U(VI) as an example and focusing on colloids, capable of transporting U(VI) on long distances. The sediment is composed of two main phases: quartz and clay minerals (glauconite, with a small fraction of kaolinite and smectite), with relative amounts of 91 and 6% in weight, respectively. The aquifer water contains clay colloids, invisible to the eye though observed with SEM and TEM in a non disturbed sample. No signal was measured with usual light diffusion techniques and Asymmetric Flow Field-Flow Fractionation (AF4). Only the Laser Induced Breakdown Detection (LIBD) technique could characterize the size (between 30 and 70 nm) and the concentration (around 10 ppb) of the clay colloids. Batch experiments were carried out to define U(VI)-Quartz and U(VI)-Clay interactions, with U(VI) concentration, pH and pCO 2 being the studied variables. The data were modelled with the Chess geochemistry code developed at the Paris School of Mines and compared to literature. Davis applied model for U(VI)-Quartz interaction and Bradbury and Baeyens applied model for U(VI)-Illite interaction adequately describe the experimental data. To know if clay colloids can move freely in the groundwater, pore size was measured using X-ray microtomography. Nanoparticles tracing was done with

  13. Migration of uranium in the presence of clay colloids in a sandy aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Le Cointe, P. [Laboratoire SUBATECH, UMR 6457 Ecole des Mines/CNRS/Universite, 4 rue A. Kastler, BP 20722, 44307 Nantes Cedex 03 (France); Centre de Geosciences, Ecole des Mines de Paris, 35 rue St-Honore, 77305 Fontainebleau Cedex (France); ANDRA 1/7 rue Jean Monnet - 92298 Chatenay Malabry Cedex (France); Grambow, B.; Piscitelli, A.; Montavon, G. [Laboratoire SUBATECH, UMR 6457 Ecole des Mines/CNRS/Universite, 4 rue A. Kastler, BP 20722, 44307 Nantes Cedex 03 (France); Van der Lee, J. [EDF R ete D, Site des Renardieres, Route de Sens - Ecuelles, 77250 Moret sur Loing (France); Giffaut, E.; Schneider, V. [ANDRA 1/7 rue Jean Monnet - 92298 Chatenay Malabry Cedex (France)


    Document available in extended abstract form only. In France, low and medium level radioactive waste of short period (nuclides with a half-life less than 31 years and an activity ranging from 100 to 1,000,000 Bq/g) is stored in concrete constructions on a surface site in Soulaines-Dhuys (Aube). The site was chosen for its simple geology: it entirely lays on an aquifer formation, the Upper Aptian sands, above a Lower Aptian impermeable clay formation. The site is surrounded by the Noues d'Amance stream, which serves as the single outlet of the groundwater on the site. The objective of this study is to improve knowledge of radionuclides migration in the aquifer formation to improve safety, using U(VI) as an example and focusing on colloids, capable of transporting U(VI) on long distances. The sediment is composed of two main phases: quartz and clay minerals (glauconite, with a small fraction of kaolinite and smectite), with relative amounts of 91 and 6% in weight, respectively. The aquifer water contains clay colloids, invisible to the eye though observed with SEM and TEM in a non disturbed sample. No signal was measured with usual light diffusion techniques and Asymmetric Flow Field-Flow Fractionation (AF4). Only the Laser Induced Breakdown Detection (LIBD) technique could characterize the size (between 30 and 70 nm) and the concentration (around 10 ppb) of the clay colloids. Batch experiments were carried out to define U(VI)-Quartz and U(VI)-Clay interactions, with U(VI) concentration, pH and pCO{sub 2} being the studied variables. The data were modelled with the Chess geochemistry code developed at the Paris School of Mines and compared to literature. Davis applied model for U(VI)-Quartz interaction and Bradbury and Baeyens applied model for U(VI)-Illite interaction adequately describe the experimental data. To know if clay colloids can move freely in the groundwater, pore size was measured using X-ray microtomography. Nanoparticles tracing was done with

  14. Spatial distributions of biogeochemical reactions in freshwater-saltwater mixing zones of sandy beach aquifers (United States)

    Kim, K. H.; Michael, H. A.; Ullman, W. J.; Cai, W. J.


    Beach aquifers host biogeochemically dynamic mixing zones between fresh and saline groundwaters of contrasting origins, histories, and compositions. Seawater, driven up the beachface by waves and tides, infiltrates into the sand and meets the seaward-discharging fresh groundwater, creating and maintaining a highly reactive intertidal circulation cell well-defined by salinity. Seawater supplies oxygen and reactive carbon to the circulation cell, supporting biogeochemical reactions within the cell that transform and attenuate dissolved nutrient fluxes from terrestrial sources. We investigated the spatial distribution of chemical reaction zones within the intertidal circulation cell at Cape Shores, Lewes, Delaware. Porewater samples were collected from multi-level wells along a beach-perpendicular transect. Samples were analyzed for particulate carbon and reactive solutes, and incubated to obtain rates of oxic respiration and denitrification. High rates of oxic respiration were observed higher on the beach, in the landward freshwater-saline water mixing zone, where dissolved oxygen availability was high. Denitrification was dominant in lower areas of the beach, below the intertidal discharge point. High respiration rates did not correlate with particulate carbon concentrations entrained within porewater, suggesting that dissolved organic carbon or immobile particulate carbon trapped within the sediment can contribute to and alter bulk reactivity. A better understanding of the sources and sinks of carbon within the beach will improve our ability to predict nutrient fluxes to estuaries and oceans, aiding the management of coastal environments and ecosystems.

  15. Sorption of benzothiazoles onto sandy aquifer material under equilibrium and nonequlibrium conditions

    Directory of Open Access Journals (Sweden)

    Kragulj Marijana M.


    Full Text Available In this study, the sorption behaviour of 1,3-benzothiazole (BT and 2-(methylthiobenzothiazole (MTBT was investigated on Danube geosorbent under equilibrium and nonequilibrium conditions. All sorption isotherms fitted well with the Freundlich model (R2=0.932-0.993. The results showed that organic matter of the Danube geosorbent has a higher sorption affinity for the more hydrophobic MTBT compared to BT. However, sorption-desorption experiments showed that MTBT was more easily desorbed than BT molecules, which indicates the importance of absorption relative to adsorption in the overall sorption mechanism of MTBT. In general, molecules of BT and MTBT were more easily desorbed in the lower concentration range, which resulted in an increase in the hysteresis indices with increasing concentrations. Column experiments revealed that retention of the investigated compounds on the aquifer material followed the compound’s hydrophobicity. BT showed a lower retention, in accordance with its lower sorption affinity obtained in the static experiments, while MTBT showed a greater sorption affinity, and thus had a longer retention time on the column. Thus during transport BT represent greater risk for groundwaters than MTBT. These results have increased our understanding of benzothiazoles sorption and desorption process which represent one of the most important factors which influence the behaviour of organic compounds in the environment.

  16. Soil moisture spatio-temporal behavior of Pinus pinaster stands on sandy flatlands of central Spain.

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Sanz, V.; Garcia-Vinas, J. I.


    Pinus pinaster stands in the center of the Iberian Peninsula frequently grow in a unique hydrological system characterized by a variable groundwater table near the soil surface and highly permeable soils (arenosols). Over the last few decades, this superficial aquifer has been overused as a water resource, especially for irrigated crops. Overuse has reached a critical level and has caused various environmental impacts and a water sustainability crisis wherein rainfall variability does not allow for a sufficient level of aquifer recharge by natural means. Within this changing scenario, soil water significantly affects the spatio-temporal ecological response, necessitating more extensive characterization of the complex soil-tree water relationship. The primary goal of the present work was to evaluate the influence of root zone soil moisture on the observed spatial response of Pinus pinaster stands. Volumetric soil moisture content was measured at eleven forest sites, using time-domain reflectometry (TDR), over a two-year observation period. The results demonstrate that the combined effect of groundwater table proximity and dune morphology associated with this area are the main factors driving very different water availability conditions among the monitored hydrological response units, which modulate maritime pine installation and development. Topographically lower areas are more heterogeneous in terms of soil moisture behavior. In these areas, the conifer forests that are connected to the water table may be the most sensitive to land use changes within current environmental change scenarios. Consequently, in these pine ecosystems, the combined influences of geomorphology and water table proximity on variations in root zone soil moisture are essential and must be considered to develop adequate adaptive management models. (Author) 25 refs.

  17. Spatial and temporal infiltration dynamics during managed aquifer recharge. (United States)

    Racz, Andrew J; Fisher, Andrew T; Schmidt, Calla M; Lockwood, Brian S; Los Huertos, Marc


    Natural groundwater recharge is inherently difficult to quantify and predict, largely because it comprises a series of processes that are spatially distributed and temporally variable. Infiltration ponds used for managed aquifer recharge (MAR) provide an opportunity to quantify recharge processes across multiple scales under semi-controlled conditions. We instrumented a 3-ha MAR infiltration pond to measure and compare infiltration patterns determined using whole-pond and point-specific methods. Whole-pond infiltration was determined by closing a transient water budget (accounting for inputs, outputs, and changes in storage), whereas point-specific infiltration rates were determined using heat as a tracer and time series analysis at eight locations in the base of the pond. Whole-pond infiltration, normalized for wetted area, rose rapidly to more than 1.0 m/d at the start of MAR operations (increasing as pond stage rose), was sustained at high rates for the next 40 d, and then decreased to less than 0.1 m/d by the end of the recharge season. Point-specific infiltration rates indicated high spatial and temporal variability, with the mean of measured values generally being lower than rates indicated by whole-pond calculations. Colocated measurements of head gradients within saturated soils below the pond were combined with infiltration rates to calculate soil hydraulic conductivity. Observations indicate a brief period of increasing saturated hydraulic conductivity, followed by a decrease of one to two orders of magnitude during the next 50 to 75 d. Locations indicating the most rapid infiltration shifted laterally during MAR operation, and we suggest that infiltration may function as a "variable source area" processes, conceptually similar to catchment runoff. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  18. Temporal geoelectric behaviour of dyke aquifers in northern Deccan ...

    Indian Academy of Sciences (India)

    These studies revealed changes in field characters, their attitudes, thickness and structure ... logists. However, information on the relation- .... the water table aquifer occurs at shallow depth .... from the field was processed and modelled using.

  19. Identification of TCE and PCE sorption and biodegradation parameters in a sandy aquifer for fate and transport modelling: batch and column studies. (United States)

    Kret, E; Kiecak, A; Malina, G; Nijenhuis, I; Postawa, A


    The main aim of this study was to determine the sorption and biodegradation parameters of trichloroethene (TCE) and tetrachloroethene (PCE) as input data required for their fate and transport modelling in a Quaternary sandy aquifer. Sorption was determined based on batch and column experiments, while biodegradation was investigated using the compound-specific isotope analysis (CSIA). The aquifer materials medium (soil 1) to fine (soil 2) sands and groundwater samples came from the representative profile of the contaminated site (south-east Poland). The sorption isotherms were approximately linear (TCE, soil 1, K d = 0.0016; PCE, soil 1, K d = 0.0051; PCE, soil 2, K d = 0.0069) except for one case in which the best fitting was for the Langmuir isotherm (TCE, soil 2, K f = 0.6493 and S max = 0.0145). The results indicate low retardation coefficients (R) of TCE and PCE; however, somewhat lower values were obtained in batch compared to column experiments. In the column experiments with the presence of both contaminants, TCE influenced sorption of PCE, so that the R values for both compounds were almost two times higher. Non-significant differences in isotope compositions of TCE and PCE measured in the observation points (δ(13)C values within the range of -23.6 ÷ -24.3‰ and -26.3 ÷-27.7‰, respectively) indicate that biodegradation apparently is not an important process contributing to the natural attenuation of these contaminants in the studied sandy aquifer.

  20. Temporal dynamics of gastropod fauna on subtidal sandy sediments of the Ensenada de Baiona (NW Iberian Peninsula) (United States)

    Moreira, J.; Aldea, C.; Troncoso, J. S.


    The temporal variation of the gastropod fauna inhabiting sandy sediments of the Ensenada de Baiona (Galicia, Spain) was studied at three subtidal sites from February 1996 to February 1997 by means of quantitative sampling. A total of 5,463 individuals representing 51 gastropod species and 22 families were found. The family Pyramidellidae was the most diverse in number of species (11 species), followed by Rissoidae and Trochidae (4 species each). The dogwhelk, Nassarius reticulatus, and the rissoid snail, Rissoa parva, were the numerically dominant species at the three studied sites; those and other abundant species showed their greatest densities by the end of summer and the beginning of autumn. In general, univariate measures of the assemblage (number of species, abundance, diversity and evenness) showed variations through time; greater values were recorded between summer and autumn depending on the site. Multivariate analyses done on abundance data showed certain seasonality in the evolution of the assemblage as expected for shallow subtidal sandy sediments at temperate latitudes; those seasonal changes were mostly related to variations in abundance of numerically dominant species. Although the measured sedimentary variables did not show significant correlations with faunal univariate parameters, sediment heterogeneity due to the presence of mats of Zostera marina L. and shells of dead bivalves might explain the differences in composition of the gastropod assemblage among sampling sites.

  1. In-situ metal precipitation in a zinc-aerobic, sandy aquifer by means of biological sulfate reduction

    NARCIS (Netherlands)

    Janssen, G.M.C.M.; Temminghoff, E.J.M.


    The applicability of in situ metal precipitation (ISMP) based on bacterial sulfate reduction (BSR) with molasses as carbon source was tested for the immobilization of a zinc plume in an aquifer with highly unsuitable initial conditions (high Eh, low pH, low organic matter content, and low sulfate

  2. Surface-NMR measurements of the longitudinal relaxation time T1 in a homogeneous sandy aquifer in Skive, Denmark (United States)

    Walbrecker, J.; Behroozmand, A.


    Efficient groundwater management requires reliable means of characterizing shallow groundwater aquifers. One key parameter in this respect is hydraulic conductivity. Surface nuclear magnetic resonance (NMR) is a geophysical exploration technique that can potentially provide this type of information in a noninvasive, cost-effective way. The technique is based on measuring the precession of nuclear spins of protons in groundwater molecules. It involves large loop antennas deployed on Earth's surface to generate electromagnetic pulses tuned to specifically excite and detect groundwater proton spins. Naturally, the excited state of spins is transitory - once excited, spins relax back to their equilibrium state. This relaxation process is strongly influenced by the spin environment, which, in the case of groundwater, is defined by the aquifer. By employing empirical relations, changes in relaxation behavior can be used to identify changes in aquifer hydraulic conductivity, making the NMR relaxation signal a very important piece of information. Particularly, efforts are made to record the longitudinal relaxation parameter T1, because it is known from laboratory studies that it often reliably correlates with hydraulic conductivity, even in the presence of magnetic species. In surface NMR, T1 data are collected by recording the NMR signal amplitude following two sequential excitation pulses as a function of the delay time τ between the two pulses. In conventional acquisition, the two pulses have a mutual phase shift of π. Based on theoretical arguments it was recently shown that T1 times acquired according to this conventional surface-NMR scheme are systematically biased. It was proposed that the bias can be minimized by cycling the phase of the two pulses between π and zero in subsequent double-pulse experiments, and subtracting the resulting signal amplitudes (phase-cycled pseudosaturation recovery scheme, pcPSR). We present the first surface-NMR T1 data set recorded

  3. Hydrogeochemical and mineralogical effects of sustained CO2 contamination in a shallow sandy aquifer: A field-scale controlled release experiment

    DEFF Research Database (Denmark)

    Cahill, Aaron Graham; Marker, Pernille Aabye; Jakobsen, Rasmus


    A shallow aquifer CO2 contamination experiment was performed to investigate evolution of water chemistry and sediment alteration following leakage from geological storage by physically simulating a leak from a hypothetical storage site. In a carbonate-free aquifer, in western Denmark, a total...... of 1600 kg of gas phase CO2 was injected at 5 and 10 m depth over 72 days through four inclined injection wells into aeolian and glacial sands. Water chemistry was monitored for pH, EC, and dissolved element evolution through an extensive network of multilevel sampling points over 305 days. Sediment cores...... were taken pre and postinjection and analyzed to search for effects on mineralogy and sediment properties. Results showed the simulated leak to evolve in two distinct phases; an advective elevated ion pulse followed by increasing persistent acidification. Spatial and temporal differences in evolution...

  4. Temporal and spatial variations in groundwater quality resulting from policy-induced reductions in nitrate leaching to the Rabis Creek aquifer, Denmark (United States)

    Jessen, Søren; Engesgaard, Peter; Thorling, Lærke; Müller, Sascha; Leskelä, Jari; Postma, Dieke


    Twenty-five years of annual groundwater quality monitoring data from the sandy unconfined Rabis Creek aquifer were used to assess the effects of political actions aimed to reduce nitrate leaching to the aquifer. Data were collected from eight multilevel samplers along a ˜3 km transect, which follows the general direction of groundwater flow. Each multilevel sampler comprises 20 screens placed with a 1 m vertical distance from near the water table downwards. The transect covers areas of livestock, plantation & heath, and agriculture. The history of nitrate leaching to the aquifer was assessed using data from screens close to the water table of multilevel samplers placed within agricultural areas. According to these data, nitrate concentrations of infiltrating 'agricultural' water peaked at 2-3 mM (120-180 mg/L) in the year 1989, and then gradually decreased and stabilized at 0.25-1.0 mM (15-60 mg/L) from year 2000. Local farmers declare having used the maximum fertilization rate allowed during the period. The timing of the observed decrease therefore suggests a direct link to the political action plans implemented in the same period. Parallel to the development in nitrate leaching, although with a transport time lag, the average concentration of nitrate in the oxic zone of the aquifer was roughly halved between 2000 and 2013. As a response to political initiatives of the late 1980'ies, part of the area covering the aquifer was changed from agriculture to non-fertilized grass for livestock; the data shows that this effectively remediated the aquifer underneath in less than 20 years, to become nitrate-free and attain background sulfate levels. The oxidized and pyritic reduced zone of the aquifer is separated by a <1 m redoxcline. Denitrification by the pyrite releases sulfate that is retained down-gradient as a tracer for historical nitrate loading to the aquifer. Thus sulfate concentrations currently increase in the multilevel samplers positioned furthest down

  5. Aquifers (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  6. Analytical Analyses of Spatial and Temporal Characteristics of Infiltrated Water for Managed Aquifer Recharge (United States)

    Zlotnik, V. A.; Ledder, G.; Kacimov, A. R.


    Disposal of excessive runoff or treated sewage into wadis and ephemeral streams is a common practice and an important hydrological problem in many Middle Eastern countries. While chemical and biological properties of the injected treated wastewater may be different from those of the receiving aquifer, the density contrast between the two fluids can be small. Therefore, studies of the fluid interface for variable density fluids or water intrusion are not directly relevant in many Managed Aquifer Recharge (MAR) problems. Other factors, such as the transient nature of injection and lack of detailed aquifer information must be considered. The disposed water reaching the water table through the vadose zone creates groundwater mounds, deforms the original water table, and develops finite-size convex-concave lenses of treated water over receiving water. After cessation of infiltration, these mounds flatten, water levels become horizontal, and infiltrated water becomes fully embedded in the receiving aquifer. The shape of the treated water body is controlled by the aquifer parameters, the magnitude of ambient flow, and the duration, rate, and cyclicity of infiltration. In case of limited aquifer data, advective transport modeling offers the most appropriate tools for predicting plume shapes over time, but surprisingly little work has been done on this important 3D flow problem. We investigate the lateral and vertical spreading of infiltrated water combining techniques of spatial velocity analyses by Zlotnik and Ledder (1992, 1993) with particle tracking. This approach allows for evaluating the geometry of the plume and the protection zone, the flow development phases, and other temporal and spatial effects and results can be used in conditions of limited data availability and quality. (Funding was provided by the USAID, DAI Subcontract 1001624-12S-19745)

  7. Spatial and temporal dynamics of the microbial community in the Hanford unconfined aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xueju; McKinley, James P.; Resch, Charles T.; Kaluzny, Rachael M.; Lauber, C.; Fredrickson, Jim K.; Knight, Robbie C.; Konopka, Allan


    Pyrosequencing analysis of 16S rRNA genes was used to study temporal dynamics of groundwater Bacteria and Archaea over 10 months within 3 well clusters separated by ~30 m and located 250 m from the Columbia River on the Hanford Site, WA. Each cluster contained 3 wells screened at different depths ranging from 10 to 17 m that differed in hydraulic conductivities. Representative samples were selected for analyses of prokaryotic 16S and eukaryotic 18S rRNA gene copy numbers. Temporal changes in community composition occurred in all 9 wells over the 10 month sampling period. However, there were particularly strong effects near the top of the water table when the seasonal rise in the Columbia River caused river water intrusion at the top of the aquifer. The occurrence and disappearance of some microbial assemblages (such as Actinobacteria ACK-M1) were correlated to river water intrusion. This seasonal impact on microbial community structure was greater in the shallow saturated zone than deeper in the aquifer. Spatial and temporal patterns for several 16S rRNA gene operational taxonomic units associated with particular physiological functions (e.g.methane oxidizers and metal reducers) suggests dynamic changes in fluxes of electron donors and acceptors over an annual cycle. In addition, temporal dynamics in eukaryotic 18S rRNA gene copies and the dominance of protozoa in 18S clone libraries suggest that bacterial community dynamics could be affected not only by the physical and chemical environment, but also by top-down biological control.

  8. Temporal variation of sandy beach macrofauna at two sites with distinct environmental conditions on Cassino Beach, extreme southern Brazil

    Directory of Open Access Journals (Sweden)

    Pedro de Sá Rodrigues da Silva


    Full Text Available Temporal variations of the macrofauna of sandy beaches have been related to variations in the beach morphodynamics and also to the population dynamics of dominant species. The aim of this article is to describe the temporal variation of the intertidal macrofauna at two sites with distinct environmental condition on Cassino Beach, extreme southern Brazil. At each site three transect lines 50 m apart were defined perpendicular to the shore line, from which samples were collected monthly in triplicate at 4 intertidal levels (10 m apart from June 2004 to May 2005. During winter a generally low density was observed, due to the absence of recruitments and to the mud deposition, which occurred just before sampling (in April 2004, and to low intensity stranding events. Spring witnessed a population explosion of Scolelepis gaucha, a migration of Mesodesma mactroides adults from the subtidal zone, and a strong stranding event. In the summer, recruitment of M. mactroides, Donax hanleyanus and Emerita brasiliensis was observed. Fall was characterized by low densities, except for D. hanleyanus recruitment. The macrofauna at both sites showed a striking seasonal variation in density and diversity, perhaps attributable to the recruitment of numerically dominant species and physical disturbances (stranding and mud deposition.Variações sazonais da macrofauna bentônica de praias arenosas têm sido relacionadas com variações da morfodinâmica da praia e também aos recrutamentos das espécies dominantes. Este trabalho objetiva avaliar a variabilidade temporal da macrofauna da zona entremarés de dois locais com distintas características ambientais na praia do Cassino, extremo sul do Brasil. Em cada local foram demarcadas três transversais (separadas por 50m perpendiculares à linha de água, nas quais amostras foram coletadas em triplicata em 4 níveis entremarés (separados por 10 m, entre junho/2004 e maio/2005. Durante o inverno ocorreram baixas

  9. Groundwater Quality: Analysis of Its Temporal and Spatial Variability in a Karst Aquifer. (United States)

    Pacheco Castro, Roger; Pacheco Ávila, Julia; Ye, Ming; Cabrera Sansores, Armando


    This study develops an approach based on hierarchical cluster analysis for investigating the spatial and temporal variation of water quality governing processes. The water quality data used in this study were collected in the karst aquifer of Yucatan, Mexico, the only source of drinking water for a population of nearly two million people. Hierarchical cluster analysis was applied to the quality data of all the sampling periods lumped together. This was motivated by the observation that, if water quality does not vary significantly in time, two samples from the same sampling site will belong to the same cluster. The resulting distribution maps of clusters and box-plots of the major chemical components reveal the spatial and temporal variability of groundwater quality. Principal component analysis was used to verify the results of cluster analysis and to derive the variables that explained most of the variation of the groundwater quality data. Results of this work increase the knowledge about how precipitation and human contamination impact groundwater quality in Yucatan. Spatial variability of groundwater quality in the study area is caused by: a) seawater intrusion and groundwater rich in sulfates at the west and in the coast, b) water rock interactions and the average annual precipitation at the middle and east zones respectively, and c) human contamination present in two localized zones. Changes in the amount and distribution of precipitation cause temporal variation by diluting groundwater in the aquifer. This approach allows to analyze the variation of groundwater quality controlling processes efficiently and simultaneously. © 2017, National Ground Water Association.

  10. Spatial and temporal changes in sulphate-reducing groundwater bacterial community structure in response to Managed Aquifer Recharge. (United States)

    Reed, D A; Toze, S; Chang, B


    The population dynamics of bacterial able to be cultured under sulphate reducing condition was studied in conjunction with changes in aquifer geochemistry using multivariate statistics for two contrasting Managed Aquifer Recharge (MAR) techniques at two different geographical locations (Perth, Western Australia and Adelaide, South Australia). Principal component analysis (PCA) was used to investigate spatial and temporal changes in the overall chemical signature of the aquifers using an array of chemical analytes which demonstrated a migrating geochemical plume. Denaturing Gradient Gel Electrophoresis (DGGE) using DNA from sulphate-reducing bacteria cultures was used to detect spatial and temporal changes in population dynamics. Bacterial and geochemical evidence suggested that groundwater at greatest distance from the nutrient source was least affected by treated effluent recharge. The results suggested that bacterial populations that were able to be cultured in sulphate reducing media responded to the migrating chemical gradient and to the changes in aquifer geochemistry. Most noticeably, sulphate-reducing bacterial populations associated with the infiltration galleries were stable in community structure over time. Additionally, the biodiversity of these culturable bacteria was restored when aquifer geochemistry returned to ambient conditions during the recovery phase at the Adelaide Aquifer Storage and Recovery site. Copyright CSIRO 2008.

  11. Multi-temporal InSAR evidence of ground subsidence induced by groundwater withdrawal: the Montellano aquifer (SW Spain)

    NARCIS (Netherlands)

    Ruiz-Constán, A.; Ruiz-Armenteros, A.M.; Lamas-Fernández, F.; Martos-Rosillo, S.; Delgado, J.M.; Bekaert, D.P.S.; Sousa, J.J.; Gil, A.J.; Caro Cuenca, M.; Hanssen, R.F.; Galindo-Zaldívar, J.; Sanz de Galdeano, C.


    This study uses the InSAR technique to analyse ground subsidence due to intensive exploitation of an aquifer for agricultural and urban purposes in the Montellano town (SW Spain). The detailed deformation maps clearly show that the spatial and temporal extent of subsidence is controlled by

  12. Spatio-Temporal Dynamics of Land-Use and Land-Cover in the Mu Us Sandy Land, China, Using the Change Vector Analysis Technique

    Directory of Open Access Journals (Sweden)

    Arnon Karnieli


    Full Text Available The spatial extent of desertified vs. rehabilitated areas in the Mu Us Sandy Land, China, was explored. The area is characterized by complex landscape changes that were caused by different drivers, either natural or anthropogenic, interacting with each other, and resulting in multiple consequences. Two biophysical variables, NDVI, positively correlated with vegetation cover, and albedo, positively correlated with cover of exposed sands, were computed from a time series of merged NOAA-AVHRR and MODIS images (1981 to 2010. Generally, throughout the study period, NDVI increased and albedo decreased. Improved understanding of spatial and temporal dynamics of these environmental processes was achieved by using the Change Vector Analysis (CVA technique applied to NDVI and albedo data extracted from four sets of consecutive Landsat images, several years apart. Changes were detected for each time step, as well as over the entire period (1978 to 2007. Four categories of land cover were created—vegetation, exposed sands, water bodies and wetlands. The CVA’s direction and magnitude enable detecting and quantifying finer changes compared to separate NDVI or albedo difference/ratio images and result in pixel-based maps of the change. Each of the four categories has a biophysical meaning that was validated in selected hot-spots, employing very high spatial resolution images (e.g., Ikonos. Selection of images, taking into account inter and intra annual variability of rainfall, enables differentiating between short-term conservancies (e.g., drought and long-term alterations. NDVI and albedo, although comparable to tasseled cap’s brightness and greenness indices, have the advantage of being computed using reflectance values extracted from various Landsat platforms since the early 1970s. It is shown that, over the entire study period, the majority of the Mu Us Sandy Land area remained unchanged. Part of the area (6%, mainly in the east, was under human

  13. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer (United States)

    Harvey, Ronald W.; Metge, David W.; Barber, Larry B.; Aiken, George R.


    The effects of a dilute (ionic strength = 5 ?? 10-3 M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 ??g/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ???3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  14. Spatial, temporal and diel variations of fish assemblages at two sandy beaches in the Sepetiba Bay, Rio de Janeiro, Brazil (United States)

    Pessanha, André Luiz Machado; Araújo, Francisco Gerson


    Fish assemblages from two beaches, one in the inner and the other in the outer Sepetiba Bay (latitude: 22°54'-23°04'S; longitude: 43°34'-44°10'W), Southeast Brazil, were sampled by beach seine net, simultaneously, on both seasonal and diel scales, between August 1998 and June 1999. Sites were selected to encompass different environmental conditions which reflect the two bay zones, thus providing a comprehensive assessment of the factors influencing surf zone fish assemblages, and their spatial, seasonal and diel variations. A total of 55 fish species was recorded, mostly young-of-the-year. Anchoa tricolor, Micropogonias furnieri, Gerres aprion, Diapterus rhombeus, Harengula clupeola, Atherinella brasiliensis and Mugil liza were numerically dominant and contributed to 95.2% of the total fish catches. Strong differences in fish assemblages were observed between the two areas, with higher number of species in the outer bay. Increases in fish numbers occurred in winter, while the highest biomass occurred in winter and summer. Transparency, followed by salinity, was responsible for most of the spatial variability and played an important role in structuring fish assemblages. Overall, diel patterns did not reveal any significant trends; however, if we consider each season separately, an increase in fish numbers during the day with peak at sunset was observed in winter, and a higher biomass occurred at night in winter and summer. Species preferences for various combinations of environmental variables are responsible for shifts in the structure and overall abundance of assemblages and dictated some patterns. The sciaenid M. furnieri, the second most abundant species, occurred only in the inner zone, being more abundant in winter. The species of Engraulidae were more abundant in the outer zone in winter/spring during the day. The gerreids G. aprion and D. rhombeus occurred mainly in summer. Overall, temporal fluctuations act more at a specific level than at a structural

  15. Hydrometeorological daily recharge assessment model (DREAM) for the Western Mountain Aquifer, Israel: Model application and effects of temporal patterns (United States)

    Sheffer, N. A.; Dafny, E.; Gvirtzman, H.; Navon, S.; Frumkin, A.; Morin, E.


    Recharge is a critical issue for water management. Recharge assessment and the factors affecting recharge are of scientific and practical importance. The purpose of this study was to develop a daily recharge assessment model (DREAM) on the basis of a water balance principle with input from conventional and generally available precipitation and evaporation data and demonstrate the application of this model to recharge estimation in the Western Mountain Aquifer (WMA) in Israel. The WMA (area 13,000 km2) is a karst aquifer that supplies 360-400 Mm3 yr-1 of freshwater, which constitutes 20% of Israel's freshwater and is highly vulnerable to climate variability and change. DREAM was linked to a groundwater flow model (FEFLOW) to simulate monthly hydraulic heads and spring flows. The models were calibrated for 1987-2002 and validated for 2003-2007, yielding high agreement between calculated and measured values (R2 = 0.95; relative root-mean-square error = 4.8%; relative bias = 1.04). DREAM allows insights into the effect of intra-annual precipitation distribution factors on recharge. Although annual precipitation amount explains ˜70% of the variability in simulated recharge, analyses with DREAM indicate that the rainy season length is an important factor controlling recharge. Years with similar annual precipitation produce different recharge values as a result of temporal distribution throughout the rainy season. An experiment with a synthetic data set exhibits similar results, explaining ˜90% of the recharge variability. DREAM represents significant improvement over previous recharge estimation techniques in this region by providing near-real-time recharge estimates that can be used to predict the impact of climate variability on groundwater resources at high temporal and spatial resolution.

  16. Calculation of the temporal gravity variation from spatially variable water storage change in soils and aquifers

    DEFF Research Database (Denmark)

    Leiriao, Silvia; He, Xin; Christiansen, Lars


    Total water storage change in the subsurface is a key component of the global, regional and local water balances. It is partly responsible for temporal variations of the earth's gravity field in the micro-Gal (1 mu Gal = 10(-8) m s(-2)) range. Measurements of temporal gravity variations can thus...... be used to determine the water storage change in the hydrological system. A numerical method for the calculation of temporal gravity changes from the output of hydrological models is developed. Gravity changes due to incremental prismatic mass storage in the hydrological model cells are determined to give...

  17. Spatial and temporal patterns of shoreline change of a 280-km high-energy disrupted sandy coast from 1950 to 2014: SW France (United States)

    Castelle, Bruno; Guillot, Benoit; Marieu, Vincent; Chaumillon, Eric; Hanquiez, Vincent; Bujan, Stéphane; Poppeschi, Coline


    A dataset of 15 geo-referenced orthomosaics photos was generated to address long-term shoreline change along approximately 270 km of high-energy sandy coast in SW France between 1950 and 2014. The coast consists of sandy beaches backed by coastal dunes, which are only disrupted by two wide tidal inlets (Arcachon and Maumusson), a wide estuary mouth (Gironde) and a few small wave-dominated inlets and coastal towns. A time and spatially averaged erosion trend of 1.12 m/year is found over 1950-2014, with a local maximum of approximately 11 m/year and a maximum local accretion of approximately 6 m/year, respectively. Maximum shoreline evolutions are observed along coasts adjacent to the inlets and to the estuary mouth, with erosion and accretion alternating over time on the timescale of decades. The two inlet-sandspit systems of Arcachon and Maumusson show a quasi-synchronous behaviour with the two updrift coasts accreting until the 1970s and subsequently eroding since then, which suggests that shoreline change at these locations is controlled by allocyclic mechanisms. Despite sea level rise and the well-established increase in winter wave height over the last decades, there is no capture of significant increase in mean erosion rate. This is hypothesized to be partly the result of relevant coastal dune management works from the 1960s to the 1980s after a long period of coastal dune disrepair during and after the Second World War. This study suggests that long-term shoreline change of high-energy sandy coasts disrupted by inlets and/or estuaries is complex and needs to consider a wide range of parameters including, non-extensively, waves, tides, inlet dynamics, sea level rise, coastal dune management and coastal defences, which challenges the development of reliable long-term coastal evolution numerical models.

  18. Spatial and Temporal Variability of Groundwater Recharge in a Sandstone Aquifer in a Semi-Arid Region (United States)

    Manna, F.; Murray, S.; Abbey, D.; Martin, P.; Cherry, J.; Parker, B. L.


    Groundwater recharge estimates are required to constrain groundwater fluxes over a 11.5 km2 site, located on an upland ridge of southern California. The site is a decommissioned industrial research facility that features chemical contamination of the underlying sedimentary bedrock aquifer and recharge values are necessary to quantify the volumetric flow rate available to transport contaminants. As a first step to assess recharge, Manna et al. (2016) used to chloride mass balance method based on on-site measurements of bulk atmospheric chloride deposition comprised of dry fallout and precipitation, 1490 groundwater samples, and measurements of chloride in surface water runoff. However, this study only provided site-wide long-term average value and did not address spatial and temporal variability of recharge. To this purpose, a spatially distributed hydrological model was used to reflect the site-specific conditions and represent the transient nature of recharge, runoff, storage and evapotranspiration over a 20-year period in a catchment (2.16 km2) of the study area. The integrated model was developed using MIKESHE employing a 20 by 20 m finite difference grid and using on-site measured physical and hydrological input parameters. We found that recharge is highly variable across the study area, with values that span over three orders of magnitude. The main factors affecting recharge are land use and topography: lower recharge values were found in vegetated areas, whereas higher values were found in areas with exposed bedrock at the surface and along the main drainages of the catchment. Analyzing the seasonal variability of the water budget components, evapotranspiration is the dominant process throughout the year and recharge occurs episodically only during the winter season. These results are validated by the comparison of measured and simulated water levels and overland flow rates and are consistent with a previous study carried out at the site using the chloride

  19. Application of water quality index to evaluate groundwater quality (temporal and spatial variation) of an intensively exploited aquifer (Puebla valley, Mexico). (United States)

    Salcedo-Sánchez, Edith R; Garrido Hoyos, Sofía E; Esteller Alberich, Ma Vicenta; Martínez Morales, Manuel


    The spatial and temporal variation of water quality in the urban area of the Puebla Valley aquifer was evaluated using historical and present data obtained during this investigation. The current study assessed water quality based on the Water Quality Index developed by the Canadian Council of Ministers of the Environment (CCME-WQI), which provides a mathematical framework to evaluate the quality of water in combination with a set of conditions representing quality criteria, or limits. This index is flexible regarding the type and number of variables used by the evaluation given that the variables of interest are selected according to the characteristics and objectives of development, conservation and compliance with regulations. The CCME-WQI was calculated using several variables that assess the main use of the wells in the urban area that is public supply, according to criteria for human use and consumption established by Mexican law and international standards proposed by the World Health Organization. The assessment of the index shows a gradual deterioration in the quality of the aquifer over time, as the amount of wells with excellent quality have decreased and those with lower index values (poor quality) have increased throughout the urban area of the Puebla Valley aquifer. The parameters affecting groundwater quality are: total dissolved solids, sulfate, calcium, magnesium and total hardness.

  20. Microseisms from Superstorm Sandy (United States)

    Sufri, Oner; Koper, Keith D.; Burlacu, Relu; de Foy, Benjamin


    We analyzed and visualized the microseisms generated by Superstorm Sandy as recorded by the Earthscope Transportable Array (TA) during late October through early November of 2012. We applied continuous, frequency-dependent polarization analysis to the data and were able to track the course of Sandy as it approached the Florida coastline and, later, the northeastern coast of the U.S. The energy level of Sandy was roughly comparable to the background microseism level generated by wave-wave interactions in the North Atlantic and North Pacific oceans. The maximum microseismic power and degree of polarization were observed across the TA when Sandy sharply changed its direction to the west-northwest (specifically, towards Long Island, New York) on October 29. The westward turn also briefly changed the dominant microseism period from 5 s to 8 s. We identified three other microseismic source regions during the 18 day observation period. In particular, peak-splitting in the double frequency band and the orientation of the 5 s and 8 s polarization vectors revealed two contemporaneous microseism sources, one in the North Atlantic and one in the Northeast Pacific, for the dates of November 3-4. Predictions of microseismic excitation based on ocean wave models showed consistency with the observed microseismic energy generated by Sandy and other storms.

  1. Flow Patterns and Morphological Changes in a Sandy Meander Bend during a Flood—Spatially and Temporally Intensive ADCP Measurement Approach

    Directory of Open Access Journals (Sweden)

    Elina Kasvi


    Full Text Available The fluvio-geomorphological processes in meander bends are spatially uneven in distribution. Typically, higher velocities and erosion take place near the outer bank beyond the bend apex, while the inner bend point bar grows laterally towards the outer bank, increasing the bend amplitude. These dynamics maintain the meander evolution. Even though this development is found in meandering rivers independent of soil or environmental characteristics, each river still seems to behave unpredictably. The special mechanisms that determine the rate and occasion of morphological changes remain unclear. The aim of this study is to offer new insights regarding flow-induced morphological changes in meander using a novel study approach. We focused on short-term and small-spatial-scale changes by conducting a spatially and temporally (daily intensive survey during a flood (a period of nine days with an ADCP attached to a remotely controlled mini-boat. Based on our analysis, the flood duration and the rate of discharge increase and decrease seems to play key roles in determining channel changes by controlling the flow velocities and depth and the backwater effect may have notable influence on the morphological processes. We discuss themes such as the interaction of inner and outer bend processes and the longer-term development of meander bends.

  2. The Temporal and Spatial Variability of the Confined Aquifer Head and Storage Properties in the San Luis Valley, Colorado Inferred From Multiple InSAR Missions (United States)

    Chen, Jingyi; Knight, Rosemary; Zebker, Howard A.


    Interferometric Synthetic Aperture Radar (InSAR) data from multiple satellite missions were combined to study the temporal and spatial variability of head and storage properties in a confined aquifer system on a decadal time scale. The area of study was a 4,500 km2 agricultural basin in the San Luis Valley (SLV), Colorado. We had available previous analyses of C-band ERS-1/2 data from June 1992 to November 2000, and L-band ALOS PALSAR data from October 2009 to March 2011. We used C-band Envisat data to fill in the time period from November 2006 to July 2010. In processing the Envisat data, we successfully employed a phase interpolation between persistent scatterer pixels to reduce the impact of vegetation decorrelation, which can significantly reduce the quality of C-band InSAR data over agricultural basins. In comparing the results from the L-band ALOS data and C-band Envisat data in a 10 month overlapping time period, we found that the shorter wavelength of C-band InSAR allowed us to preserve small deformation signals that were not detectable using L-band ALOS data. A significant result was the finding that the elastic storage properties of the SLV confined aquifer system remained stable over the 20 year time period and vary slowly in space, allowing us to combine InSAR data acquired from multiple missions to fill the temporal and spatial gaps in well data. The InSAR estimated head levels were validated with well measurements, which indicate little permanent water-storage loss over the study time period in the SLV.

  3. Spatio-temporal variation in groundwater head affected by stratigraphic heterogeneity of the alluvial aquifer in Northwest India (United States)

    van Dijk, W. M.; Joshi, S. K.; Densmore, A. L.; Jackson, C. R.; Sutanudjaja, E.; Lafare, A. E. A.; Gupta, S.; Mackay, J. D.; Mason, P. J.; Sinha, R.


    Groundwater is a primary source of freshwater in the alluvial aquifer system of northwestern India. Unsustainable exploitation of the groundwater resources has led to a regional hotspot in groundwater depletion. Rapid groundwater-level decline shows spatial variation, as the effects of various stresses, including precipitation, potential evapotranspiration and abstraction, are likely to be influenced by the stratigraphic and geomorphic heterogeneity between sediment fan and interfan areas (see Geomorphological map in Figure A). We used a transfer function-noise (TFN) time series approach to quantify the effect of the various stress components in the period 1974-2010, based on predefined impulse response functions (IRFs) of von Asmuth et al. (2008). The objective of this study was 1) to acquire the impulse response function of various stresses, 2) assess the spatial estimation parameter (the zeroth moment, M0) of the spatial development of the groundwater head and 3) relate the spatial M0 to the observed stratigraphic and geomorphic heterogeneity. We collected information on the groundwater head pre- and post-monsoon, the district-wise monthly precipitation and potential evapotranspiration, and we modeled the monthly abstraction rate using land-use information. The TFN identified the IRF of precipitation as well as abstraction. The IRF, summarized in the parameter M0, identified a hotspot for the abstraction stress (see M0 spatial map for abstraction in Figure B) at the margins of the Sutlej and Yamuna fans. No hotspot is observed for the precipitation stress, but the M0 for precipitation increases with distance from the Himalayan front. At larger distances from the Himalayan front, observed groundwater head rises cannot be explained by the IRFs for the abstraction and precipitation stresses. This is likely because the current TFN models do not account for other stresses, such as recharge by canal leakage, which are locally important. We conclude that the spatial

  4. A reconnaissance spatial and temporal assessment of methane and inorganic constituents in groundwater in bedrock aquifers, Pike County, Pennsylvania, 2012-13 (United States)

    Senior, Lisa A.


    Pike County in northeastern Pennsylvania is underlain by the Devonian-age Marcellus Shale and other shales, formations that have potential for natural gas development. During 2012–13, the U.S. Geological Survey in cooperation with the Pike County Conservation District conducted a reconnaissance study to assess baseline shallow groundwater quality in bedrock aquifers prior to possible shale-gas development in the county. For the spatial component of the assessment, 20 wells were sampled in summer 2012 to provide data on the occurrence of methane and other aspects of existing groundwater quality throughout the county, including concentrations of inorganic constituents commonly present at low levels in shallow, fresh groundwater but elevated in brines. For the temporal component of the assessment, 4 of the 20 wells sampled in summer 2012 were sampled monthly from July 2012 through June 2013 to provide data on seasonal variability in groundwater quality. All water samples were analyzed for major ions, nutrients, selected inorganic trace constituents (including metals and other elements), stable isotopes of water, radon-222, gross alpha- and gross beta-particle activity, dissolved gases (methane, ethane, and ethene), and, if possible, isotopic composition of methane. Additional analyses for boron and strontium isotopes, age-dating of water, and radium-226 were done on water samples collected from six wells in June 2013.

  5. Alluvial Aquifer (United States)

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

  6. Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark

    DEFF Research Database (Denmark)

    Hinsby, K.; Hojberg, A.L.; Engesgaard, P.


    Vertical profiles of the chlorofluorocarbons CFC-11, CFC-12, and CFC-113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the Rabis Creek, Denmark...

  7. Depth and temporal variations in water quality of the Snake River Plain aquifer in well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Frederick, D.B.; Johnson, G.S.


    In-situ measurements of the specific conductance and temperature of ground water in the Snake River Plain aquifer were collected in observation well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory. These parameters were monitored at various depths in the aquifer from October 1994 to August 1995. The specific conductance of ground water in well USGS-59, as measured in the borehole, ranged from about 450 to 900 microS/cm at standard temperature (25 C). The pumping cycle of the production wells at the Idaho Chemical Processing Plant causes changes in borehole circulation patterns, and as a result the specific conductance of ground water at some depths in the well varies by up to 50% over a period of about 14 hours. However, these variations were not observed at all depths, or during each pumping cycle. The temperature of ground water in the well was typically between 12.8 and 13.8 C. The results of this study indicate that temporal variations in specific conductance of the ground water at this location are caused by an external stress on the aquifer--pumping of a production well approximately 4,000 feet away. These variations are believed to result from vertical stratification of water quality in the aquifer and a subsequent change in intrawell flow related to pumping. When sampling techniques that do not induce a stress on the aquifer (i.e., thief sampling) are used, knowledge of external stresses on the system at the time of sampling may aid in the interpretation of geochemical data

  8. Carbonate aquifers (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen


    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  9. Enhanced degradation of mono aromatic hydrocarbons in sandy aquifer materials

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, Henry X. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria; Weber Junior, W.J. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering


    The use of an inoculation technique to enhance rates of in-situ biodegradation of toxic organic contaminants by increasing subsurface populations of specific microorganisms is described. An external biologically active carbon (BAC) adsorber is demonstrated to be an efficient reactor system for collection, acclimation and enrichment of microorganisms for the inoculation process (author). 15 refs., 3 figs.

  10. Enhanced degradation of mono aromatic hydrocarbons in sandy aquifer materials

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, Henry X [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria; Weber, Junior, W J [Michigan Univ., Ann Arbor, MI (United States). Dept. of Civil and Environmental Engineering


    The use of an inoculation technique to enhance rates of in-situ biodegradation of toxic organic contaminants by increasing subsurface populations of specific microorganisms is described. An external biologically active carbon (BAC) adsorber is demonstrated to be an efficient reactor system for collection, acclimation and enrichment of microorganisms for the inoculation process (author). 15 refs., 3 figs.

  11. Fate of herbicides in deep subsurface limestone and sandy aquifers

    DEFF Research Database (Denmark)

    Janniche, Gry Sander

    afgørende for at vurdere herbiciders skæbne i underjord og grundvandsmagasiner. PhD-projektet har undersøgt sorption og nedbrydning af fire model-herbicider (atrazin, acetochlor, mecoprop og isoproturon) i kalksten og sandede grundvands¬magasiner. Desuden er den rumlige småskala-variation af herbicidernes...... tydelig selv inden for få cm afstand over dybden, og betydningen af denne variation afhænger af den samlede udbredelse af lag med forhøjet sorption eller nedbrydning; 2) at kalk/kalksten yder ringe beskyttelse mod grundvands¬forurening med mecoprop, atrazin, isoproturon og acetochlor, da sorptionen er lav...... og mineraliseringen meget langsom for isoproturon, acetochlor og mecoprop, og atrazin ikke er nedbrydeligt; 3) at i sandede grundvands¬magasiner er sorptionen af de fire herbicider generelt lav, men kan under reducerede forhold være kraftig for især isoproturon og acetochlor. Mecoprop, isoproturon og...

  12. Sandy PMO Disaster Relief Appropriations Act of 2013 Financial Data (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...

  13. Ozark Aquifer (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base and top, the extent, and the potentiometric surface of the Ozark aquifer in Kansas. The Ozark...

  14. Hurricane Sandy Poster (October 29, 2012) (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...

  15. Guarani aquifer

    International Nuclear Information System (INIS)


    The environmental protection and sustain ability develop project of Guarani Aquifer System is a join work from Argentina, Brazil, Paraguay and Uruguay with a purpose to increase the knowledge resource and propose technical legal and organizational framework for sustainable management between countries.The Universities funds were created as regional universities support in promotion, training and academic research activities related to environmental al social aspects of the Guarani Aquifer System.The aim of the project is the management and protection of the underground waters resources taking advantage and assesment for nowadays and future generations

  16. The importance of transient flow simulation in the numerical model of the Guarani Aquifer System; Importancia de la formulacion del regimen temporal de flujo en el modelo numerico del Sistema Acuifero Guarani

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, A.; Vives, L.; Rodriguez, L.; Cota, S. D. S.


    A regional groundwater flow model under a steady-state regime has been developed within the framework of the Project for the Environmental Protection and Sustainable Development of the Guarani Aquifer System. The model has allowed the comparison of several plausible hypotheses concerning different conceptual models, mainly with regard to alternative hydraulic conductivity zoning. We assess here the influence of the flow regime, either steady-state or temporal, on the magnitude of hydraulic conductivity and the water balance. The response time to various external stresses is also analyzed. The results indicate that the effect of increasing pumping is immediately noticeable close to pumping wells whilst the effect manifests with a lag time, though less intensively, as the distance from the pumping centre increments. The effect of pumping would be imperceptible 300 km away, at least for the simulated conditions in a 100-year scenario. (Author)

  17. Science and Sandy: Lessons Learned (United States)

    Werner, K.


    Following Hurricane Sandy's impact on the mid-Atlantic region, President Obama established a Task Force to '...ensure that the Federal Government continues to provide appropriate resources to support affected State, local, and tribal communities to improve the region's resilience, health, and prosperity by building for the future.' The author was detailed from NOAA to the Task Force between January and June 2013. As the Task Force and others began to take stock of the region's needs and develop plans to address them, many diverse approaches emerged from different areas of expertise including: infrastructure, management and construction, housing, public health, and others. Decision making in this environment was complex with many interests and variables to consider and balance. Although often relevant, science and technical expertise was not always at the forefront of this process. This talk describes the author's experience with the Sandy Task Force focusing on organizing scientific expertise to support the work of the Task Force. This includes a description of federal activity supporting Sandy recovery efforts, the role of the Task Force, and lessons learned from developing a science support function within the Task Force.

  18. Hydrological connectivity of perched aquifers and regional aquifers in semi-arid environments: a case study from Namibia (United States)

    Hamutoko, J. T.; Wanke, H.


    Integrated isotopic and hydrological tracers along with standard hydrological data are used to understand complex dry land hydrological processes on different spatial and temporal scales. The objective of this study is to analyse the relationship between the perched aquifers and the regional aquifer using hydrochemical data and isotopic composition in the Cuvelai-Etosha Basin in Namibia. This relation between the aquifers will aid in understanding groundwater recharge processes and flow dynamics. Perched aquifers are discontinuous shallow aquifers with water level ranging from 0 to 30 meters below ground level. The regional aquifer occurs in semi-consolidated sandstone at depths between about 60 and 160 meters below ground level. Water samples were collected from both aquifers in 10 villages and were analysed for major ions and stable isotopes. The results show overlapping hydrochemistry and isotopic compositions of both aquifers in 8 villages which suggest the possibility of perched aquifer water infiltrating into the regional aquifer. In two villages the hydrochemistry and isotopic composition of the aquifers are totally different and this suggests that there is no interaction between this aquifers. Areas where perched aquifers are connected to regional aquifers maybe recharge zones. These finding have important implications for groundwater resource management.

  19. L'aquifère du bassin de la Mamora, Maroc: geometrie et ecoulements souterrainsThe aquifer of the Mamora Basin, Morocco: geometry and groundwater flow (United States)

    Zouhri, L.


    The Mamora aquifer, in the northern Moroccan Meseta, constitutes the main regional water resource. Its impermeable basement is mostly composed of blue marls. The lithostratigraphy of the basin aquifer is characterised by a sequence of sandstones, sandy limestones, conglomerates and sandy clays. The structure of the basement of the Mamora aquifer, deduced from electrical resistivity measurements, allowed the hydrogeological behaviour of the reservoir, and the direction of the groundwater flow, to be established. The combination of the lithological, morphological, piezometric, geophysical and structural investigations revealed a northward thickening of the substrate with groundwater flow towards the Rharb (to the north) and towards the Atlantic Ocean (northwest). This 'multicriteria' approach enabled a structural model to be defined, which correlated well with the aquifer geometry and the groundwater flow. The variability of the hydrogeological units, and the northward thickening of the sedimentary facies, were controlled by northeast-southwest orientated faults, which affect their impermeability.

  20. The ecology of sandy beaches in Natal

    African Journals Online (AJOL)

    The ecology of sandy beaches in Natal. A.H. Dye, A. Mclachlan and T. Wooldridge. Department of Zoology, University of Port Elizabeth, Port Elizabeth. Data from an ecological survey of four sandy beaches on the. Natal coast of South Africa are presented. Physical para· meters such as beach profile, particle size, moisture, ...

  1. 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.


    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


    Directory of Open Access Journals (Sweden)

    JJ Siang


    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.

  3. Sandy a změna klimatu

    Czech Academy of Sciences Publication Activity Database

    Pecho, Jozef


    Roč. 92, č. 7 (2013), s. 408-411 ISSN 0042-4544 Institutional support: RVO:68378289 Keywords : hurricanes * climate change Subject RIV: DG - Athmosphere Sciences, Meteorology

  4. 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...

  5. Measurement of biological oxygen demand sandy beaches

    African Journals Online (AJOL)

    Measurements of biological oxygen demand in a sandy beach using conventional .... counting the cells present in a sample of aged seawater and comparing this with .... This activity peaked at 71 % above the undisturbed level after 16 hours.

  6. Groundwater recharge assessment at local and episodic scale in a soil mantled perched karst aquifer in southern Italy (United States)

    Allocca, V.; De Vita, P.; Manna, F.; Nimmo, John R.


    Groundwater recharge assessment of karst aquifers, at various spatial and temporal scales, is a major scientific topic of current importance, since these aquifers play an essential role for both socio-economic development and fluvial ecosystems.

  7. Strength Characteristics of Reinforced Sandy Soil


    S. N. Bannikov; Mahamed Al Fayez


    Laboratory tests on determination of reinforced sandy soil strength characteristics (angle of internal friction, specific cohesive force) have been carried out with the help of a specially designed instrument and proposed methodology. Analysis of the obtained results has revealed that cohesive forces are brought about in reinforced sandy soil and an angle of internal soil friction becomes larger in comparison with non-reinforced soil.

  8. Quantifying the synergistic effect of the precipitation and land use on sandy desertification at county level: a case study in Naiman Banner, Northern China. (United States)

    Xiaodong, Ge; Jinren, Ni; Zhenshan, Li; Ronggui, Hu; Xin, Ming; Qing, Ye


    Assessing the driving forces of sandy desertification is fundamental and important for its control. It has been widely accepted that both climatic conditions and land use have great impact on sandy desertification in northern China. However, the relative role and synergistic effect of each driving force of sandy desertification are still not clear. In this paper, an indicator named as SI was defined to represent the integrated probability of sandy desertification caused by land use. A quantitative method was developed for characterizing the relative roles of annual precipitation and land use to sandy desertification in both spatial and temporal dimensions at county level. Results showed that, at county level, land use was the main cause of sandy desertification for Naiman Banner since 1987-2009. In the case of spatial dimension, the different combination of land use types decided the distribution of sandy desertification probability and finally decided the spatial pattern of bared sand land. In the case of temporal dimension, the synergistic effect of land use and precipitation highly influenced the spatial distribution of sandy desertification. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Operational Group Sandy technical progress report (United States)



    Hurricane Sandy made US landfall near Atlantic City, NJ on 29 October 2012, causing 72 direct deaths, displacing thousands of individuals from damaged or destroyed dwellings, and leaving over 8.5 million homes without power across the northeast and mid-Atlantic. To coordinate federal rebuilding activities in the affected region, the President established the cabinet-level Hurricane Sandy Rebuilding Task Force (Task Force). The Task Force was charged with identifying opportunities for achieving rebuilding success while supporting economic vitality, improving public health and safety, protecting and enhancing natural and manmade infrastructure, bolstering resilience, and ensuring appropriate accountability.

  10. Modelling contaminant transport in saturated aquifers

    International Nuclear Information System (INIS)

    Lakshminarayana, V.; Nayak, T.R.


    With the increase in population and industrialization the problem of pollution of groundwater has become critical. The present study deals with modelling of pollutant transport through saturated aquifers. Using this model it is possible to predict the concentration distribution, spatial as well as temporal, in the aquifer. The paper also deals with one of the methods of controlling the pollutant movement, namely by pumping wells. A simulation model is developed to determine the number, location and rate of pumping of a number of wells near the source of pollution so that the concentration is within acceptable limits at the point of interest. (Author) (18 refs., 14 figs., tab.)

  11. Sandy Hook : alternative access concept plan and vehicle replacement study (United States)


    This study addresses two critical issues of concern to the Sandy Hook Unit of Gateway National : Recreational Area: (1) options for alternative access to Sandy Hook during peak summer season, : particularly when the park is closed to private vehicles...

  12. The ecology of sandy beaches in Transkei

    African Journals Online (AJOL)

    Data from an ecological survey of three sandy beaches in. Transkei and from Gulu beach on the eastern Cape coast,. South Africa, are presented. Physical parameters such as beach profile, sand particle size, Eh and carbonate content, as well as abundance, composition, biomass and distribution of the macrofauna and ...

  13. Lessons from Hurricane Sandy for port resilience. (United States)


    New York Harbor was directly in the path of the most damaging part of Hurricane Sandy causing significant impact on many of the : facilities of the Port of New York and New Jersey. The U.S. Coast Guard closed the entire Port to all traffic before the...

  14. Transportation during and after Hurricane Sandy. (United States)


    "Hurricane Sandy demonstrated the strengths and limits of the transportation infrastructure in New York City and the surrounding region. As a result of the timely and thorough preparations by New York City and the MTA, along with the actions of city ...

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

    CSIR Research Space (South Africa)

    Bally, R


    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...

  16. Composição e variabilidade espaço-temporal da meiofauna de uma praia arenosa na região amazônica (Ajuruteua, Pará Composition and spatio-temporal variability of meiofauna community on a sandy beach in the Amazon region (Ajuruteua, Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Tatianne P. Gomes


    Full Text Available Este trabalho avalia a variabilidade espaço-temporal da meiofauna do médiolitoral na praia de Ajuruteua, Estado do Pará. As coletas foram realizadas a cada dois meses, entre abril de 2003 a fevereiro de 2004 durante as marés de sizígia, em diferentes zonas da praia. As amostras foram retiradas com um amostrador cilíndrico de 3,14 cm² e fixadas em formalina salina a 5%. Em laboratório, as amostras foram passadas em malha de 0,063 mm de abertura e os organismos retidos identificados em nível de grandes grupos taxonômicos, contados e fixados em álcool etílico a 70%. A meiofauna esteve representada por oito grupos: Turbellaria, Nematoda, Tardigrada, Polychaeta, Oligochaeta, Acari, adultos de Copepoda Harpacticoida e juvenis de Copepoda Harpacticoida. Nematoda foi o grupo dominante, representando 74% do total de indivíduos, seguido de Copepoda (19%. Pôde-se observar clara zonação horizontal da fauna, que se distribuiu em três faixas paralelas à linha de praia, com características significativamente distintas quanto à abundância, riqueza e densidade dos principais grupos taxonômicos. No médiolitoral médio foram observados valores significativamente mais elevados de riqueza e abundância, enquanto os valores mais baixos foram registrados no médiolitoral superior e inferior. A comunidade de meiofauna, ainda que não tenha variado significativamente entre períodos climáticos, foi mais rica e abundante nos meses secos. Os principais fatores responsáveis pelas variações espaço-temporais da meiofauna foram a ação das ondas e das marés e as variações na salinidade da água.The present study investigates the spatio-temporal changes in the meiofauna community along the intertidal zone of Ajuruteua Beach, State of Pará, Brazil. Samples were collected during spring tides at different levels of the beach face every two months from April 2003 to February 2004. The material was sampled using a cylindrical corer (3.14 cm² and

  17. Inherent mineralization of 2,6-dichlorobenzamide (BAM) in unsaturated zone and aquifers - Effect of initial concentrations and adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Janniche, Gry Sander, E-mail: [DTU Environment, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby (Denmark); Clausen, Liselotte; Albrechtsen, Hans-Jorgen [DTU Environment, Technical University of Denmark, Building 113, DK-2800 Kgs. Lyngby (Denmark)


    The dichlobenil metabolite BAM (2,6-dichlorobenzamide) is frequently detected in aquifers e.g. in Denmark despite the mother compound dichlobenil was banned here since 1997. BAM mineralization was investigated at environmentally relevant concentrations in sediment samples. Undisturbed sediment cores with known dichlobenil application were collected from topsoil to 8.5 m below surface resulting in 57 samples hereof 4 aquifer samples. Mineralization was only substantial (>10%) in the uppermost meter of the unsaturated zone. Microbial adaptation, observed as faster mineralization in pre-exposed than in pristine sediments from the same location, was only evident in sandy sediment where dichlobenil was still present, but not in clayey sediments. Higher initial concentrations (1-5000 {mu}g/kg) did not stimulate mineralization in pristine clayey or sandy sediments, or in pre-exposed sand. However, in pre-exposed clay mineralization was stimulated at high concentrations. Furthermore BAM was for the first time mineralized in aerobic aquifer sediments from different BAM-contaminated groundwater locations. - Highlights: > BAM mineralized in BAM-contaminated aerobic aquifer sediments. > In subsurface, fastest BAM mineralization in pre-exposed sandy sediments. > Increased mineralization (adaptation) only observed in contaminated sandy sediment. > In pristine sediments mineralization ratio increased with decreasing concentrations. - BAM mineralization in subsurface and groundwater was demonstrated.

  18. Impacts of convection on high-temperature aquifer thermal energy storage (United States)

    Beyer, Christof; Hintze, Meike; Bauer, Sebastian


    Seasonal subsurface heat storage is increasingly used in order to overcome the temporal disparities between heat production from renewable sources like solar thermal installations or from industrial surplus heat and the heat demand for building climatisation or hot water supply. In this context, high-temperature aquifer thermal energy storage (ATES) is a technology to efficiently store and retrieve large amounts of heat using groundwater wells in an aquifer to inject or withdraw hot or cold water. Depending on the local hydrogeology and temperature amplitudes during high-temperature ATES, density differences between the injected hot water and the ambient groundwater may induce significant convective flow components in the groundwater flow field. As a consequence, stored heat may accumulate at the top of the storage aquifer which reduces the heat recovery efficiency of the ATES system. Also, an accumulation of heat at the aquifer top will induce increased emissions of heat to overlying formations with potential impacts on groundwater quality outside of the storage. This work investigates the impacts of convective heat transport on the storage efficiency of a hypothetical high-temperature ATES system for seasonal heat storage as well as heat emissions to neighboring formations by numerical scenario simulations. The coupled groundwater flow and heat transport code OpenGeoSys is used to simulate a medium scale ATES system operating in a sandy aquifer of 20 m thickness with an average groundwater temperature of 10°C and confining aquicludes at top and bottom. Seasonal heat storage by a well doublet (i.e. one fully screened "hot" and "cold" well, respectively) is simulated over a period of 10 years with biannual injection / withdrawal cycles at pumping rates of 15 m³/h and for different scenarios of the temperature of the injected water (20, 35, 60 and 90 °C). Simulation results show, that for the simulated system significant convective heat transport sets in when

  19. Hydrologic analysis of data for the Lost Lake Aquifer Zone of the Steel Pond Aquifer at recovery well RWM-16

    International Nuclear Information System (INIS)

    Wells, D.G.; Cook, J.W.; Hiergesell, R.A.


    This report presents the results of an analysis of data obtained from a large-scale, multiple-well aquifer test of the sandy unit referred to as the Lost Lake Aquifer Zone of the Steed Pond Aquifer in an area just south of the A and M Areas. Pumping was conducted at recovery well RWM-16, which is located near the MSB-40 well cluster, approximately 4000 feet south of the M-Area Basin. RWM-16 is located in the lower left portion of Figure 1, which also illustrates the general relationship of the testing site to the A and M Areas and other monitor wells. The data generated from testing RWM-16 was used to calculate estimates of transmissivity and storage for the aquifer system within which RWM-16 is screened. These parameters are related to hydraulic conductivity and storativity of the aquifer system by the vertical thickness of the unit. The leakage coefficient for the overlying confining unit is also estimated. This information is needed to refine conceptual understanding of the groundwater flow system beneath the A and M Areas. The refined conceptual model will more adequately describe the pattern of groundwater flow, and will contribute to updating the open-quotes Zone of Captureclose quotes model that has been used in the initial phases of designing a groundwater remediation system in the A and M Areas

  20. Responses of soil fungal community to the sandy grassland restoration in Horqin Sandy Land, northern China. (United States)

    Wang, Shao-Kun; Zuo, Xiao-An; Zhao, Xue-Yong; Li, Yu-Qiang; Zhou, Xin; Lv, Peng; Luo, Yong-Qing; Yun, Jian-Ying


    Sandy grassland restoration is a vital process including re-structure of soils, restoration of vegetation, and soil functioning in arid and semi-arid regions. Soil fungal community is a complex and critical component of soil functioning and ecological balance due to its roles in organic matter decomposition and nutrient cycling following sandy grassland restoration. In this study, soil fungal community and its relationship with environmental factors were examined along a habitat gradient of sandy grassland restoration: mobile dunes (MD), semi-fixed dunes (SFD), fixed dunes (FD), and grassland (G). It was found that species abundance, richness, and diversity of fungal community increased along with the sandy grassland restoration. The sequences analysis suggested that most of the fungal species (68.4 %) belonged to the phylum of Ascomycota. The three predominant fungal species were Pleospora herbarum, Wickerhamomyces anomalus, and Deconica Montana, accounting for more than one fourth of all the 38 species. Geranomyces variabilis was the subdominant species in MD, Pseudogymnoascus destructans and Mortierella alpine were the subdominant species in SFD, and P. destructans and Fungi incertae sedis were the dominant species in FD and G. The result from redundancy analysis (RDA) and stepwise regression analysis indicated that the vegetation characteristics and soil properties explain a significant proportion of the variation in the fungal community, and aboveground biomass and C:N ratio are the key factors to determine soil fungal community composition during sandy grassland restoration. It was suggested that the restoration of sandy grassland combined with vegetation and soil properties improved the soil fungal diversity. Also, the dominant species was found to be alternative following the restoration of sandy grassland ecosystems.

  1. Rebuilding Emergency Care After Hurricane Sandy. (United States)

    Lee, David C; Smith, Silas W; McStay, Christopher M; Portelli, Ian; Goldfrank, Lewis R; Husk, Gregg; Shah, Nirav R


    A freestanding, 911-receiving emergency department was implemented at Bellevue Hospital Center during the recovery efforts after Hurricane Sandy to compensate for the increased volume experienced at nearby hospitals. Because inpatient services at several hospitals remained closed for months, emergency volume increased significantly. Thus, in collaboration with the New York State Department of Health and other partners, the Health and Hospitals Corporation and Bellevue Hospital Center opened a freestanding emergency department without on-site inpatient care. The successful operation of this facility hinged on key partnerships with emergency medical services and nearby hospitals. Also essential was the establishment of an emergency critical care ward and a system to monitor emergency department utilization at affected hospitals. The results of this experience, we believe, can provide a model for future efforts to rebuild emergency care capacity after a natural disaster such as Hurricane Sandy. (Disaster Med Public Health Preparedness. 2014;0:1-4).

  2. Swashed away? Storm impacts on sandy beach macrofaunal communities (United States)

    Harris, Linda; Nel, Ronel; Smale, Malcolm; Schoeman, David


    Storms can have a large impact on sandy shores, with powerful waves eroding large volumes of sand off the beach. Resulting damage to the physical environment has been well-studied but the ecological implications of these natural phenomena are less known. Since climate change predictions suggest an increase in storminess in the near future, understanding these ecological implications is vital if sandy shores are to be proactively managed for resilience. Here, we report on an opportunistic experiment that tests the a priori expectation that storms impact beach macrofaunal communities by modifying natural patterns of beach morphodynamics. Two sites at Sardinia Bay, South Africa, were sampled for macrofauna and physical descriptors following standard sampling methods. This sampling took place five times at three- to four-month intervals between April 2008 and August 2009. The second and last sampling events were undertaken after unusually large storms, the first of which was sufficiently large to transform one site from a sandy beach into a mixed shore for the first time in living memory. A range of univariate (linear mixed-effects models) and multivariate (e.g. non-metric multidimensional scaling, PERMANOVA) methods were employed to describe trends in the time series, and to explore the likelihood of possible explanatory mechanisms. Macrofaunal communities at the dune-backed beach (Site 2) withstood the effects of the first storm but were altered significantly by the second storm. In contrast, macrofauna communities at Site 1, where the supralittoral had been anthropogenically modified so that exchange of sediments with the beach was limited, were strongly affected by the first storm and showed little recovery over the study period. In line with predictions from ecological theory, beach morphodynamics was found to be a strong driver of temporal patterns in the macrofaunal community structure, with the storm events also identified as a significant factor, likely

  3. Effects of a Changing Climate on Seasonal Variation in Natural Recharge of Unconfined Coastal Aquifers (United States)

    Antonellini, Marco; Nella Mollema, Pauline


    Irregular rainfall patterns throughout the year result in the discontinuous natural recharge of coastal aquifers, which has an effect on the size of freshwater lenses present in sandy deposits. The thickness of the freshwater lenses is important in the context of farmland salinization and coastal ecosystems survival. This study presents numerical models that simulate continuous and discontinuous recharge in sandy coastal aquifers and the thickness of resulting fresh water lenses under current and future climate scenarios. Temperature data for the period 1960-1990 from LOCCLIM FAO and from the IPCC SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration. Potential recharge was defined as the difference between the precipitation and potential evapotranspiration in twelve locations around the world: Ameland (The Netherlands), Auckland and Wellington (New Zealand), Hong Kong, Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. These locations have shallow coastal aquifers along low lying coasts and comparable aquifer structure, which is the result of similar sediment supply and deposition in the Holocene as well as by the sea level changes from the last ice age to the present time. Particular attention has been paid to temporal variations of natural recharge that can vary from continuous recharge throughout the year to discontinuous recharge. The most dramatic reduction in the magnitude of potential annual recharge by the end of this century will occur at lower latitudes (Mumbai, Singapore, Hong Kong and Mekong). The most pronounced change in length of the dry period occurs for Kobe (Japan) and Singapore even though the total annual amount of recharge remains practically the same. The Influence of variable recharge on the size of freshwater lenses surrounded by saline water is simulated with the SEAWAT model. Models where the recharge is applied

  4. Aquifer test to determine hydraulic properties of the Elm aquifer near Aberdeen, South Dakota (United States)

    Schaap, Bryan D.


    The Elm aquifer, which consists of sandy and gravelly glacial-outwash deposits, is present in several counties in northeastern South Dakota. An aquifer test was conducted northeast of Aberdeen during the fall of 1999 to determine the hydraulic properties of the Elm aquifer in that area. An improved understanding of the properties of the aquifer will be useful in the possible development of the aquifer as a water resource. Historical water-level data indicate that the saturated thickness of the Elm aquifer can change considerably over time. From September 1977 through November 1985, water levels at three wells completed in the Elm aquifer near the aquifer test site varied by 5.1 ft, 9.50 ft, and 11.1 ft. From June 1982 through October 1999, water levels at five wells completed in the Elm aquifer near the aquifer test site varied by 8.7 ft, 11.4 ft, 13.2 ft, 13.8 ft, and 19.7 ft. The water levels during the fall of 1999 were among the highest on record, so the aquifer test was affected by portions of the aquifer being saturated that might not be saturated during drier times. The aquifer test was conducted using five existing wells that had been installed prior to this study. Well A, the pumped well, has an operating irrigation pump and is centrally located among the wells. Wells B, C, D, and E are about 70 ft, 1,390 ft, 2,200 ft, and 3,100 ft, respectively, in different directions from Well A. Using vented pressure transducers and programmable data loggers, water-level data were collected at the five wells prior to, during, and after the pumping, which started on November 19, 1999, and continued a little over 72 hours. Based on available drilling logs, the Elm aquifer near the test area was assumed to be unconfined. The Neuman (1974) method theoretical response curves that most closely match the observed water-level changes at Wells A and B were calculated using software (AQTESOLV for Windows Version 2.13-Professional) developed by Glenn M. Duffield of Hydro

  5. The role of sediment compaction and groundwater withdrawal in local sea-level rise, Sandy Hook, New Jersey, USA (United States)

    Johnson, Christopher S.; Miller, Kenneth G.; Browning, James V.; Kopp, Robert E.; Khan, Nicole S.; Fan, Ying; Stanford, Scott D.; Horton, Benjamin P.


    The rate of relative sea-level (RSL) rise at Sandy Hook, NJ (4.0 ± 0.5 mm/yr) was higher than The Battery, NY (3.0 ± 0.3 mm/yr) from 1900 to 2012 despite being separated by just 26 km. The difference cannot be explained by differential glacial isostatic adjustment (GIA; 1.4 ± 0.4 and 1.3 ± 0.4 mm/yr RSL rise, respectively) alone. We estimate the contribution of sediment compaction to subsidence at Sandy Hook using high-resolution grain size, percent organic matter, and porosity data from three upper Quaternary (≤13,350 cal yr) cores. The organic matter content (indicates that compaction of deglacial silts likely reduced the column thickness by 10-20% over the past 13,350 cal yrs. While compaction rates were high immediately after the main silt deposition (13,350-13,150 cal yrs BP), rates decreased exponentially after deposition to an average 20th century rate of 0.16 mm/yr (90% Confidence Interval (C.I.), 0.06-0.32 mm/yr). The remaining ∼0.7 mm/yr (90% C.I. 0.3-1.2 mm/yr) difference in subsidence between Sandy Hook and The Battery is likely due to anthropogenic groundwater withdrawal. Historical data from Fort Hancock wells (2 km to the southeast of the Sandy Hook tide gauge) and previous regional work show that local and regional water extraction lowered the water levels in the aquifers underlying Sandy Hook. We suggest that the modern order of contribution to subsidence (highest to lowest) appears to be GIA, local/regional groundwater extraction, and compaction of thick Quaternary silts.

  6. Geochemistry at the sulfate reduction-methanogenesis transition zone in an anoxic aquifer

    DEFF Research Database (Denmark)

    Jakobsen, Rasmus; Cold, L.


    The study addresses a 10 m deep phreatic postglacial sandy aquifer of vertically varying lithology and horizontally varying infiltration water chemistry, displaying calcite dissolution, ion-exchange, and anaerobic redox processes. The simple variations in lithology and infiltration combine into a...... by implementing specific energy yields for the microbial redox processes, could explain most of the observed groundwater geochemistry as an expression of a closely coupled system of mineral equilibria and redox processes occurring at partial equilibrium....

  7. EPA Sole Source Aquifers (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  8. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl


    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  9. Epidemic gasoline exposures following Hurricane Sandy. (United States)

    Kim, Hong K; Takematsu, Mai; Biary, Rana; Williams, Nicholas; Hoffman, Robert S; Smith, Silas W


    Major adverse climatic events (MACEs) in heavily-populated areas can inflict severe damage to infrastructure, disrupting essential municipal and commercial services. Compromised health care delivery systems and limited utilities such as electricity, heating, potable water, sanitation, and housing, place populations in disaster areas at risk of toxic exposures. Hurricane Sandy made landfall on October 29, 2012 and caused severe infrastructure damage in heavily-populated areas. The prolonged electrical outage and damage to oil refineries caused a gasoline shortage and rationing unseen in the USA since the 1970s. This study explored gasoline exposures and clinical outcomes in the aftermath of Hurricane Sandy. Prospectively collected, regional poison control center (PCC) data regarding gasoline exposure cases from October 29, 2012 (hurricane landfall) through November 28, 2012 were reviewed and compared to the previous four years. The trends of gasoline exposures, exposure type, severity of clinical outcome, and hospital referral rates were assessed. Two-hundred and eighty-three gasoline exposures were identified, representing an 18 to 283-fold increase over the previous four years. The leading exposure route was siphoning (53.4%). Men comprised 83.0% of exposures; 91.9% were older than 20 years of age. Of 273 home-based calls, 88.7% were managed on site. Asymptomatic exposures occurred in 61.5% of the cases. However, minor and moderate toxic effects occurred in 12.4% and 3.5% of cases, respectively. Gastrointestinal (24.4%) and pulmonary (8.4%) symptoms predominated. No major outcomes or deaths were reported. Hurricane Sandy significantly increased gasoline exposures. While the majority of exposures were managed at home with minimum clinical toxicity, some patients experienced more severe symptoms. Disaster plans should incorporate public health messaging and regional PCCs for public health promotion and toxicological surveillance.

  10. Ogallala Aquifer Mapping Program

    International Nuclear Information System (INIS)


    A computerized data file has been established which can be used efficiently by the contour-plotting program SURFACE II to produce maps of the Ogallala aquifer in 17 counties of the Texas Panhandle. The data collected have been evaluated and compiled into three sets, from which SURFACE II can generate maps of well control, aquifer thickness, saturated thickness, water level, and the difference between virgin (pre-1942) and recent (1979 to 1981) water levels. 29 figures, 1 table

  11. Geological study for identifying potential aquifer zone in Pakes and Bandung Villages, Konang District, Bangkalan Region

    International Nuclear Information System (INIS)

    I Gde Sukadana


    Konang District has a problem on fresh water supply particularly in dry season. Two villages in the district, namely Pakes and Konang, are densely populated areas having agriculture activities, so available of sufficient fresh water is necessary. A fresh water source that can be developed in this area is deep groundwater source from potential aquifers. A geological study has been conducted to identify potential aquifer based on lithological aspect and geological structure. According to the regional stratigraphy. the study area consists of Tawun Formation and Ngrayong Formation. They compose of carbonaceous clay stone (the oldest rock unit), carbonaceous clay stone with sandy limestone intercalations, sandy limestone interbed with carbonaceous clay stone, tuff sandstone with clay stone intercalations, and reef limestone (the youngest) respectively. Strike and dip positions of the rocks layers are N110°E/22° - N150°E/26°, located on the south anticline axis with wavy plan to gentle slope of hilly morphology. Among the rock unit, only sandy limestone has fine sand with sub angular in shape and open pack. Qualitatively. this rock has good porosity and permeability and is enables to save and to flow subsurface water. Thus. the sandy limestone is considered as a potential zone for fresh water resources. Whereas, carbonaceous clay stone with clay grain size has low porosity and permeability, so it is potential as a cap rock. (author)

  12. Characterizing a complex aquifer system using geophysics, hydrodynamics and geochemistry: A new distribution of Miocene aquifers in the Zéramdine and Mahdia-Jébéniana blocks (east-central Tunisia) (United States)

    Lachaal, Fethi; Bédir, Mourad; Tarhouni, Jamila; Gacha, Ayadi Ben; Leduc, Christian


    The Zéramdine and Mahdia-Jébéniana blocks are located in the Sahel region in east-central Tunisia. Active tectonics have divided the region into numerous sub-units, as result of multiple phases of distension and compression. The Miocene fluvio-deltaic sediment sandy layers have aquiferous capacities but their hydraulic properties are still unknown, due to the lack of investigation wells. This study proposes a new description of the regional hydrogeology of Miocene deposits. Seismic-reflection and wireline logging of petroleum and water wells were used to understand the structure and the geometry of the Miocene reservoirs. The groundwater flow and its relationship to the sedimentary and tectonic context were then identified by studying piezometry and hydrochemistry. Two Miocene deep aquifer systems were identified: (1) Zéramdine-Béni Hassen to the north and (2) Jébéniana-Ksour Essef to the south. These aquifers are separated by the Mahdia graben. Other major tectonic structures, such as the Zéramdine fault corridor, the Moknine graben, and the El-Jem half-graben represent lateral boundaries for these aquifers. Other deeper sandy and clayey-sandy reservoirs were also identified in the area. Their repartition, thickness and depth vary from one block to other. Hydrodynamics of the deep aquifers seems to be controlled by geological structures. Two independent compartments were identified: in the northern block groundwater flows from West to East and from Northwest to Southeast, while in the southern block it flows from Northwest to Southeast. Geochemical facies are of two types: Na-Ca-Cl-SO 4 for the Zéramdine-Béni Hassen deep aquifer and Na-Cl for the Jébéniana-Ksour Essef deep aquifer. The hydrodynamic and geochemical results confirm the sharing of the Miocene sediments into two aquifers.

  13. Radon emanation coefficients in sandy soils

    International Nuclear Information System (INIS)

    Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.


    In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

  14. Hurricane Sandy science plan: coastal impact assessments (United States)

    Stronko, Jakob M.


    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. Estimation of Nitrogen Pools in Irrigated Potato Production on Sandy Soil Using the Model SUBSTOR (United States)

    Prasad, Rishi; Hochmuth, George J.; Boote, Kenneth J.


    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-1N) 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. PMID:25635904

  16. Correlation between landscape fragmentation and sandy desertification: a case study in Horqin Sandy Land, China. (United States)

    Ge, Xiaodong; Dong, Kaikai; Luloff, A E; Wang, Luyao; Xiao, Jun; Wang, Shiying; Wang, Qian


    The exact roles of landscape fragmentation on sandy desertification are still not fully understood, especially with the impact of different land use types in spatial dimension. Taking patch size and shape into consideration, this paper selected the Ratio of Patch Size and the Fractal Dimension Index to establish a model that reveals the association between the area of bare sand land and the fragmentation of different land use types adjacent to bare sand land. Results indicated that (1) grass land and arable land contributed the most to landscape fragmentation processes in the regions adjacent to bare sand land during the period 1980 to 2010. Grass land occupied 54 % of the region adjacent to bare sand land in 1980. The Ratio of Patch Size of grass land decreased from 1980 to 2000 and increased after 2000. The Fractal Dimension Index of grass increased during the period 1980 to 1990 and decreased after 1990. Arable land expanded significantly during this period. The Ratio of Patch Size of arable land increased from 1980 to 1990 and decreased since 1990. The Fractal Dimension Index of arable land increased from 1990 to 2000 and decreased after 2000. (2) The Ratio of Patch Size and the Fractal Dimension Index were significantly related to the area of bare sand land. The role of landscape fragmentation was not linear to sandy desertification. There were both positive and negative effects of landscape fragmentation on sandy desertification. In 1980, the Ratio of Patch Size and the Fractal Dimension Index were negatively related to the area of bare sand land, showing that the landscape fragmentation and regularity of patches contributed to the expansion of sandy desertification. In 1990, 2000, and 2010, the Ratio of Patch Size and the Fractal Dimension Index were mostly positively related to the area of bare sand land, showing the landscape fragmentation and regularity of patches contributed to the reversion of sandy desertification in this phase. The absolute values of

  17. [Monitoring of water and salt transport in silt and sandy soil during the leaching process]. (United States)

    Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei


    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.

  18. Viability of natural attenuation in a petroleum-contaminated shallow sandy aquifer

    International Nuclear Information System (INIS)

    Jin Yong Lee; Kang Kun Lee


    This study focused on evaluating and quantifying the potential of natural attenuation of groundwater at a petroleum-contaminated site in an industrial area of a satellite city of Seoul, Korea. Groundwater at the study site was contaminated with toluene, ethylbenzene and xylene (TEX). Eight rounds of groundwater sampling and subsequent chemical analyses were performed over a period of 3 years. The groundwater quality data suggest that TEX concentrations at this site have been decreasing with time and that the TEX plume is at a quasi-steady state. Trend analysis, changes in mass flux and plume area also confirmed that the TEX plume has reached a quasi-steady state. The proportion of the total attenuation attributable to biodegradation has decreased over the monitoring period while contribution of other attenuation processes, such as dilution or dispersion, has increased. Based on the calculated attenuation rates, it would take more than 20 years to clean up the site by natural attenuation alone. (author)

  19. Viability of natural attenuation in a petroleum-contaminated shallow sandy aquifer

    International Nuclear Information System (INIS)

    Lee, Jin-Yong; Lee, Kang-Kun


    More than 20 years would be required to clean up the site by natural attenuation alone. - This study focused on evaluating and quantifying the potential of natural attenuation of groundwater at a petroleum-contaminated site in an industrial area of a satellite city of Seoul, Korea. Groundwater at the study site was contaminated with toluene, ethylbenzene and xylene (TEX). Eight rounds of groundwater sampling and subsequent chemical analyses were performed over a period of 3 years. The groundwater quality data suggest that TEX concentrations at this site have been decreasing with time and that the TEX plume is at a quasi-steady state. Trend analysis, changes in mass flux and plume area also confirmed that the TEX plume has reached a quasi-steady state. The proportion of the total attenuation attributable to biodegradation has decreased over the monitoring period while contribution of other attenuation processes, such as dilution or dispersion, has increased. Based on the calculated attenuation rates, it would take more than 20 years to clean up the site by natural attenuation alone

  20. The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers

    KAUST Repository

    Satyawali, Yamini; Seuntjens, Piet; Van Roy, Sandra; Joris, Ingeborg; Vangeel, Silvia; Dejonghe, Winnie; Vanbroekhoven, Karolien


    Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy

  1. Modelling the morphology of sandy spits

    DEFF Research Database (Denmark)

    Pedersen, Dorthe; Deigaard, Rolf; Fredsøe, Jørgen


    The shape, dimensions and growth rate of an accumulating sandy spit is investigated by a theoretical and experimental study. The idealised case of a spit growing without change of form under a constant wave forcing is considered. The longshore wave-driven sediment transport is taken to be dominant...... that with this assumption the dimensions of the spit cannot be determined. The width and shape of a finite spit is therefore determined from simulations with an area model for the wave-driven current and sediment transport along the spit. In this case the curvature effects from the spit on the longshore sediment transport...... conducted in a wave tank an accumulating spit was formed at the down-drift end of a uniform stretch of coast exposed to waves approaching at an angle. The spit approached equilibrium dimensions when a constant wave climate was applied. The radius of curvature of the spit varied according to the height...

  2. Groundwater level responses to precipitation variability in Mediterranean insular aquifers (United States)

    Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique


    Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

  3. Hydrogeology of Two Areas of the Tug Hill Glacial-Drift Aquifer, Oswego County, New York (United States)

    Miller, Todd S.; Bugliosi, Edward F.; Hetcher-Aguila, Kari K.; Eckhardt, David A.


    Two water-production systems, one for the Village of Pulaski and the other for the Villages of Sandy Creek and Lacona in Oswego County, New York, withdraw water from the Tug Hill glacial-drift aquifer, a regional sand and gravel aquifer along the western flank of the Tug Hill Plateau, and provide the sole source of water for these villages. As a result of concerns about contamination of the aquifer, two studies were conducted during 2001 to 2004, one for each water-production system, to refine the understanding of ground-water flow surrounding these water-production systems. Also, these studies were conducted to determine the cause of the discrepancy between ground-water ages estimated from previously constructed numerical ground-water-flow models for the Pulaski and Sandy Creek/Lacona well fields and the apparent ground-water ages determined using concentrations of tritium and chlorofluorocarbons. The Village of Pulaski withdrew 650,000 gallons per day in 2000 from four shallow, large-diameter, dug wells finished in glaciolacustrine deposits consisting of sand with some gravelly lenses 3 miles east of the village. Four 2-inch diameter test wells were installed upgradient from each production well, hydraulic heads were measured, and water samples collected and analyzed for physical properties, inorganic constituents, nutrients, bacteria, tritium, dissolved gases, and chlorofluorocarbons. Recharge to the Tug Hill glacial-drift aquifer is from precipitation directly over the aquifer and from upland sources in the eastern part of the recharge area, including (1) unchannelized runoff from till and bedrock hills east of the aquifer, (2) seepage to the aquifer from streams that drain the Tug Hill Plateau, (3) ground-water inflow from the till and bedrock on the adjoining Tug Hill Plateau. Water-quality data collected from four piezometers near the production wells in November 2003 indicated that the water is a calcium-bicarbonate type with iron concentrations that

  4. Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches (United States)

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


    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.

  5. Fate of Arsenic during Red River Water Infiltration into Aquifers beneath Hanoi, Vietnam. (United States)

    Postma, Dieke; Mai, Nguyen Thi Hoa; Lan, Vi Mai; Trang, Pham Thi Kim; Sø, Helle Ugilt; Nhan, Pham Quy; Larsen, Flemming; Viet, Pham Hung; Jakobsen, Rasmus


    Recharge of Red River water into arsenic-contaminated aquifers below Hanoi was investigated. The groundwater age at 40 m depth in the aquifer underlying the river was 1.3 ± 0.8 years, determined by tritium-helium dating. This corresponds to a vertical flow rate into the aquifer of 19 m/year. Electrical conductivity and partial pressure of CO 2 (P CO 2 ) indicate that water recharged from the river is present in both the sandy Holocene and gravelly Pleistocene aquifers and is also abstracted by the pumping station. Infiltrating river water becomes anoxic in the uppermost aquifer due to the oxidation of dissolved organic carbon. Further downward, sedimentary carbon oxidation causes the reduction of As-containing Fe-oxides. Because the release of arsenic by reduction of Fe-oxides is controlled by the reaction rate, arsenic entering the solution becomes highly diluted in the high water flux and contributes little to the groundwater arsenic concentration. Instead, the As concentration in the groundwater of up to 1 μM is due to equilibrium-controlled desorption of arsenic, adsorbed to the sediment before river water started to infiltrate due to municipal pumping. Calculations indicate that it will take several decades of river water infiltration to leach arsenic from the Holocene aquifer to below the World Health Organization limit of 10 μg/L.

  6. Fate of Arsenic during Red River Water Infiltration into Aquifers beneath Hanoi, Vietnam (United States)


    Recharge of Red River water into arsenic-contaminated aquifers below Hanoi was investigated. The groundwater age at 40 m depth in the aquifer underlying the river was 1.3 ± 0.8 years, determined by tritium–helium dating. This corresponds to a vertical flow rate into the aquifer of 19 m/year. Electrical conductivity and partial pressure of CO2 (PCO2) indicate that water recharged from the river is present in both the sandy Holocene and gravelly Pleistocene aquifers and is also abstracted by the pumping station. Infiltrating river water becomes anoxic in the uppermost aquifer due to the oxidation of dissolved organic carbon. Further downward, sedimentary carbon oxidation causes the reduction of As-containing Fe-oxides. Because the release of arsenic by reduction of Fe-oxides is controlled by the reaction rate, arsenic entering the solution becomes highly diluted in the high water flux and contributes little to the groundwater arsenic concentration. Instead, the As concentration in the groundwater of up to 1 μM is due to equilibrium-controlled desorption of arsenic, adsorbed to the sediment before river water started to infiltrate due to municipal pumping. Calculations indicate that it will take several decades of river water infiltration to leach arsenic from the Holocene aquifer to below the World Health Organization limit of 10 μg/L. PMID:27958705

  7. Filtration and transport of Bacillus subtilis spores and the F-RNA phage MS2 in a coarse alluvial gravel aquifer: implications in the estimation of setback distances. (United States)

    Pang, Liping; Close, Murray; Goltz, Mark; Noonan, Mike; Sinton, Lester


    Filtration of Bacillus subtilis spores and the F-RNA phage MS2 (MS2) on a field scale in a coarse alluvial gravel aquifer was evaluated from the authors' previously published data. An advection-dispersion model that is coupled with first-order attachment kinetics was used in this study to interpret microbial concentration vs. time breakthrough curves (BTC) at sampling wells. Based on attachment rates (katt) that were determined by applying the model to the breakthrough data, filter factors (f) were calculated and compared with f values estimated from the slopes of log (cmax/co) vs. distance plots. These two independent approaches resulted in nearly identical filter factors, suggesting that both approaches are useful in determining reductions in microbial concentrations over transport distance. Applying the graphic approach to analyse spatial data, we have also estimated the f values for different aquifers using information provided by some other published field studies. The results show that values of f, in units of log (cmax/co) m(-1), are consistently in the order of 10(-2) for clean coarse gravel aquifers, 10(-3) for contaminated coarse gravel aquifers, and generally 10(-1) for sandy fine gravel aquifers and river and coastal sand aquifers. For each aquifer category, the f values for bacteriophages and bacteria are in the same order-of-magnitude. The f values estimated in this study indicate that for every one-log reduction in microbial concentration in groundwater, it requires a few tens of meters of travel in clean coarse gravel aquifers, but a few hundreds of meters in contaminated coarse gravel aquifers. In contrast, a one-log reduction generally only requires a few meters of travel in sandy fine gravel aquifers and sand aquifers. Considering the highest concentration in human effluent is in the order of 10(4) pfu/l for enteroviruses and 10(6) cfu/100 ml for faecal coliform bacteria, a 7-log reduction in microbial concentration would comply with the drinking

  8. Assessment of the groundwater chemistry of a complex aquifer system in the context of urbanization in Sub-Saharan Africa: case study in semiarid southwest Niger (United States)

    Boubakar Hassane, A.; Favreau, G.; Leduc, C.; Ousmane, B.; Soumaila, A.


    The groundwater chemistry in the local vicinity of the city of Niamey was investigated in order to identify the origin of the groundwater mineralization and, in particular, to elucidate the impact of urbanization on the groundwater resources. Sources of pollution of concern in the urban area are solid waste and material deposited on the ground and latrines. Contaminants from these sources are mobilized and transported by recharge and lixiviation from rising groundwater levels. Piezometric data monitoring at 70 sites was conducted monthly from March 2004 to February 2005 to evaluate the seasonal variability of groundwater levels. Groundwater samples for chemical data were collected from the major aquifers in 74 dug wells, 14 boreholes and 1 spring for 2 years (232 samples in 4 campaigns). Data were also compiled from previous studies on groundwater, rain water, surface waters, latrines and soils. Geochemical data (major ions) are used to define groundwater groups, to map their distribution in the study area, and to evaluate their origin. We combined multivariate statistical methods, scatter diagrams, ionic ratios, and Piper diagrams to decipher the processes affecting the water chemistry at large (Niamey) and local (wells) scale. The piezometric time series revealed seasonal variability in all wells indicating that the study area is a recharge zone, which enhances the transfer of contaminants from the surface. The geochemical monitoring revealed high spatial and temporal variability in chemical parameters. Processes controlling the groundwater chemistry at large scales in the aquifers include atmospheric inputs (rainfall and dust) in the poorly mineralized formations, evapotranspiration in the soil layers, and alteration of silicates. Processes specific to individual wells are production of weak acids (H2CO3) and bases (HCO3-) in soil layers near pollutant sources, leaching of ions (Ca2+, Mg2+, Na+, K+, NH4+, NO3-, Cl-, HCO3-, SO42-) from pollutants, ion exchange

  9. Hurricane Sandy: Rapid Response Imagery of the Surrounding Regions (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...

  10. Macrofauna and meiofauna of two sandy beaches at Mombasa, Kenya

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Macrofauna and meiofauna of 2 sandy beaches having medium and fine sand particles, respectively, were investigated, quantitatively Macrofauna density was highest around high water mark and progressively decreased towards low water mark Meiofauna...

  11. 2014 USGS CMGP Lidar: Sandy Restoration (Delaware and Maryland) (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:...

  12. 2014 USGS CMGP Lidar: Post Sandy (Long Island, NY) (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...

  13. 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...

  14. Model projections of atmospheric steering of Sandy-like superstorms. (United States)

    Barnes, Elizabeth A; Polvani, Lorenzo M; Sobel, Adam H


    Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy's unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

  15. On the Impact Angle of Hurricane Sandy's New Jersey Landfall (United States)

    Hall, Timothy M.; Sobel, Adam H.


    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. Reservoir architecture patterns of sandy gravel braided distributary channel

    Directory of Open Access Journals (Sweden)

    Senlin Yin


    Full Text Available The purpose of this study was to discuss shape, scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel. Lithofacies analysis, hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores, well logging, and outcrops data, and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established. The study shows: (1 The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand, while reservoir flow barrier elements are interchannel and lacustrine mudstone. (2 The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes: sheet-like distributary channel sand body, interweave strip distributary channel sand body, single strip distributary channel sand body. (3 Identification marks of single distributary channel include: elevation of sand body top, lateral overlaying, “thick-thin-thick” feature of sand bodies, interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies. (4 Nine lithofacies types were distinguished in distributary channel unit interior, different channel units have different lithofacies association sequence.

  17. Seismic velocities to characterize the soil-aquifer continuum on the Orgeval experimental basin (France) (United States)

    Pasquet, S.; Ludovic, B.; Dhemaied, A.; Flipo, N.; Guérin, R.; Mouhri, A.; Faycal, R.; Vitale, Q.


    Among geophysical methods applied to hydrogeology, seismic prospecting is frequently confined to the characterization of aquifers geometry. The combined study of pressure- (P) and shear- (SH) wave velocities (respectively Vp and Vs) can however provide information about the aquifer parameters, as it is commonly done for most fluids in hydrocarbon exploration. This approach has recently been proposed in sandy aquifers with the estimation of Vp/Vs ratio. In order to address such issues in more complex aquifer systems (e.g. unconsolidated, heterogeneous or low-permeability media) we carried out P- and SH-wave seismic surveys on the Orgeval experimental basin (70 km east from Paris, France). This basin drains a multi-layer aquifer system monitored by a network of piezometers. The upper part of the aquifer system is characterized by tabular layers well delineated all over the basin thanks to Electrical Resistivity Tomography (ERT), Time Domain ElectroMagnetic (TDEM) soundings and wells. But the lateral variability of the intrinsic properties in each layer raises questions regarding the hydrodynamics of the upper aquifer and the validity of interpolations between piezometers. A simple interpretation of P- and SH-wave first arrivals for tabular models provides 1D velocity structures in very good agreement with the stratification anticipated from ERT and nearby geological logs. Vp/Vs ratios show a strong contrast at a depth consistent with the observed water table level, reinforcing the assumption of a free upper aquifer in the area. Similar experiments have to be conducted under different hydrological conditions to validate these observations. Anticipating the need to propose lateral applications of the method, we additionally performed tomographic inversions of the recorded data to retrieve 2D Vp and Vs models. If interpreted independently, both models fail to depict the stratification of the medium and the water table level cannot be straightforwardly identified

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

    International Nuclear Information System (INIS)

    Duvert, Clément; Raiber, Matthias; Owen, Daniel D.R.; Cendón, Dioni I.; Batiot-Guilhe, Christelle; Cox, Malcolm E.


    Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO 3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO 3 –Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

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

  20. Respirable dust and quartz exposure from three South African farms with sandy, sandy loam, and clay soils. (United States)

    Swanepoel, Andrew J; Kromhout, Hans; Jinnah, Zubair A; Portengen, Lützen; Renton, Kevin; Gardiner, Kerry; Rees, David


    To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. Three farms, located in the Free State and North West provinces of South Africa, had their soil type confirmed as sandy, sandy loam, and clay; and, from these, a total of 298 respirable dust and respirable quartz measurements were collected between July 2006-November 2009 during periods of major farming operations. Values below the limit of detection (LOD) (22 μg · m(-3)) were estimated using multiple 'imputation'. Non-parametric tests were used to compare quartz exposure from the three different soil types. Exposure to respirable quartz occurred on all three farms with the highest individual concentration measured on the sandy soil farm (626 μg · m(-3)). Fifty-seven, 59, and 81% of the measurements on the sandy soil, sandy loam soil, and clay soil farm, respectively, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 μg · m(-3). Twelve and 13% of respirable quartz concentrations exceeded 100 μg · m(-3) on the sandy soil and sandy loam soil farms, respectively, but none exceeded this level on the clay soil farm. The proportions of measurements >100 μg · m(-3) were not significantly different between the sandy and sandy loam soil farms ('prop.test'; P = 0.65), but both were significantly larger than for the clay soil farm ('prop.test'; P = 0.0001). The percentage of quartz in respirable dust was determined for all three farms using measurements > the limit of detection. Percentages ranged from 0.5 to 94.4% with no significant difference in the median quartz percentages across the three farms (Kruskal-Wallis test; P = 0.91). This study demonstrates that there is significant potential for over-exposure to respirable quartz in

  1. Bioremediation of a diesel fuel contaminated aquifer: simulation studies in laboratory aquifer columns (United States)

    Hess, A.; Höhener, P.; Hunkeler, D.; Zeyer, J.


    The in situ bioremediation of aquifers contaminated with petroleum hydrocarbons is commonly based on the infiltration of groundwater supplemented with oxidants (e.g., O 2, NO 3-) and nutrients (e.g., NH 4+, PO 43-). These additions stimulate the microbial activity in the aquifer and several field studies describing the resulting processes have been published. However, due to the heterogeneity of the subsurface and due to the limited number of observation wells usually available, these field data do not offer a sufficient spatial and temporal resolution. In this study, flow-through columns of 47-cm length equipped with 17 sampling ports were filled with homogeneously contaminated aquifer material from a diesel fuel contaminated in situ bioremediation site. The columns were operated over 96 days at 12°C with artificial groundwater supplemented with O 2, NO 3- and PO 43-. Concentration profiles of O 2, NO 3-, NO 2-, dissolved inorganic and organic carbon (DIC and DOC, respectively), protein, microbial cells and total residual hydrocarbons were measured. Within the first 12 cm, corresponding to a mean groundwater residence time of < 3.6 h, a steep O 2 decrease from 4.6 to < 0.3 mg l -1, denitrification, a production of DIC and DOC, high microbial cell numbers and a high removal of hydrocarbons were observed. Within a distance of 24 to 40.5 cm from the infiltration, O 2 was below 0.1 mg l -1 and a denitrifying activity was found. In the presence and in the absence of O 2, n-alkanes were preferentially degraded compared to branched alkanes. The results demonstrate that: (1) infiltration of aerobic groundwater into columns filled with aquifer material contaminated with hydrocarbons leads to a rapid depletion of O 2; (2) O 2 and NO 3- can serve as oxidants for the mineralization of hydrocarbons; and (3) the modelling of redox processes in aquifers has to consider denitrifying activity in presence of O 2.

  2. Brazilian sandy beach macrofauna production: a review

    Directory of Open Access Journals (Sweden)

    Marcelo Petracco


    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

  3. Mobilization And Characterization Of Colloids Generated From Cement Leachates Moving Through A SRS Sandy Sediment

    International Nuclear Information System (INIS)

    Li, D.; Roberts, K.; Kaplan, D.; Seaman, J.


    Naturally occurring mobile colloids are ubiquitous and are involved in many important processes in the subsurface zone. For example, colloid generation and subsequent mobilization represent a possible mechanism for the transport of contaminants including radionuclides in the subsurface environments. For colloid-facilitated transport to be significant, three criteria must be met: (1) colloids must be generated; (2) contaminants must associate with the colloids preferentially to the immobile solid phase (aquifer); and (3) colloids must be transported through the groundwater or in subsurface environments - once these colloids start moving they become 'mobile colloids'. Although some experimental investigations of particle release in natural porous media have been conducted, the detailed mechanisms of release and re-deposition of colloidal particles within natural porous media are poorly understood. Even though this vector of transport is known, the extent of its importance is not known yet. Colloid-facilitated transport of trace radionuclides has been observed in the field, thus demonstrating a possible radiological risk associated with the colloids. The objective of this study was to determine if cementitious leachate would promote the in situ mobilization of natural colloidal particles from a SRS sandy sediment. The intent was to determine whether cementitious surface or subsurface structure would create plumes that could produce conditions conducive to sediment dispersion and mobile colloid generation. Column studies were conducted and the cation chemistries of influents and effluents were analyzed by ICP-OES, while the mobilized colloids were characterized using XRD, SEM, EDX, PSD and Zeta potential. The mobilization mechanisms of colloids in a SRS sandy sediment by cement leachates were studied.

  4. Geochemical Processes During Managed Aquifer Recharge With Desalinated Seawater (United States)

    Ganot, Y.; Holtzman, R.; Weisbrod, N.; Russak, A.; Katz, Y.; Kurtzman, D.


    We study geochemical processes along the variably-saturated zone during managed aquifer recharge (MAR) with reverse-osmosis desalinated seawater (DSW). The DSW, post-treated at the desalination plant by calcite dissolution (remineralization) to meet the Israeli water quality standards, is recharged into the Israeli Coastal Aquifer through an infiltration pond. Water quality monitoring during two MAR events using suction cups and wells inside the pond indicates that cation exchange is the dominant subsurface reaction, driven by the high Ca2+ concentration in the post-treated DSW. Stable isotope analysis shows that the shallow groundwater composition is similar to the recharged DSW, except for enrichment of Mg2+, Na+, Ca2+, and HCO3-. A calibrated variably-saturated reactive transport model is used to predict the geochemical evolution during 50 years of MAR for two water quality scenarios: (i) post-treated DSW (current practice) and (ii) soft DSW (lacking the remineralization post-treatment process). The latter scenario was aimed to test soil-aquifer-treatment (SAT) as an alternative post-treatment technique. Both scenarios provide an enrichment of ˜2.5 mg L-1 in Mg2+ due to cation exchange, compared to practically zero Mg2+ currently found in the Israeli DSW. Simulations of the alternative SAT scenario provide Ca2+ and HCO3- remineralization due to calcite dissolution at levels that meet the Israeli standard for DSW. The simulated calcite content reduction in the sediments below the infiltration pond after 50 years of MAR was low (<1%). Our findings suggest that remineralization using SAT for DSW is a potentially sustainable practice at MAR sites overlying calcareous sandy aquifers.

  5. Arsenic levels in groundwater aquifer

    African Journals Online (AJOL)

    Miodrag Jelic

    resistance (ρ); dielectric constant (ε); magnetic permeability (η); electrochemical activity ..... comprises grey sands of different particle size distribution ..... groundwater: testing pollution mechanisms for sedimentary aquifers in. Bangladesh.

  6. EPA Region 1 Sole Source Aquifers (United States)

    U.S. Environmental Protection Agency — This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of...

  7. Hydrogeology and water quality of the Dublin and Midville aquifer systems at Waynesboro, Burke County, Georgia, 2011 (United States)

    Gonthier, Gerard


    The hydrogeology and water quality of the Dublin and Midville aquifer systems were characterized in the City of Waynesboro area in Burke County, Georgia, based on geophysical and drillers’ logs, flowmeter surveys, a 24-houraquifer test, and the collection and chemical analysis of water samples in a newly constructed well. At the test site, the Dublin aquifer system consists of interlayered sands and clays between depths of 396 and 691 feet, and the Midville aquifer system consists of a sandy clay layer overlying a sand and gravel layer between depths of 728 and 936 feet. The new well was constructed with three screened intervals in the Dublin aquifer system and four screened intervals in the Midville aquifer system. Wellbore-flowmeter testing at a pumping rate of 1,000 gallons per minute indicated that 52.2 percent of the total flow was from the shallower Dublin aquifer system with the remaining 47.8 percent from the deeper Midville aquifer system. The lower part of the lower Midville aquifer (900 to 930 feet deep), contributed only 0.1 percent of the total flow. Hydraulic properties of the two aquifer systems were estimated using data from two wellbore-flowmeter surveys and a 24-hour aquifer test. Estimated values of transmissivity for the Dublin and Midville aquifer systems were 2,000 and 1,000 feet squared per day, respectively. The upper and lower Dublin aquifers have a combined thickness of about 150 feet and the horizontal hydraulic conductivity of the Dublin aquifer system averages 10 feet per day. The upper Midville aquifer, lower Midville confining unit, and lower Midville aquifer have a combined thickness of about 210 feet, and the horizontal hydraulic conductivity of the Midville aquifer system averages 6 feet per day. Storage coefficient of the Dublin aquifer system, computed using the Theis method on water-level data from one observation well, was estimated to be 0.0003. With a thickness of about 150 feet, the specific storage of the Dublin aquifer

  8. The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume. (United States)

    Ziegler, Brady A; Schreiber, Madeline E; Cozzarelli, Isabelle M


    In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This study used chemical extractions of aquifer sediments collected in 1993 and 2011-2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-suboxic transition) of the contaminated aquifer over a twenty-year period. Results show that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich "iron curtain," associated with the anoxic-suboxic transition zone, migrated 30m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established. Using results of this study coupled with historical data, we develop a conceptual model which summarizes the natural attenuation of As and Fe over time and space that can be applied to other sites that experience As mobilization due to an influx of bioavailable organic matter. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume (United States)

    Ziegler, Brady A.; Schreiber, Madeline E.; Cozzarelli, Isabelle M.


    In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This study used chemical extractions of aquifer sediments collected in 1993 and 2011–2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-suboxic transition) of the contaminated aquifer over a twenty-year period. Results show that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich “iron curtain,” associated with the anoxic-suboxic transition zone, migrated 30 m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established. Using results of this study coupled with historical data, we develop a conceptual model which summarizes the natural attenuation of As and Fe over time and space that can be applied to other sites that experience As mobilization due to an influx of bioavailable organic matter.

  10. Study of Maowusu Sandy Land Vegetation Coverage Change Based on Modis Ndvi (United States)

    Ye, Q.; Liu, H.; Lin, Y.; Han, R.


    This paper selected 2006-2016 MODIS NDVI data with a spatial resolution of 500m and time resolution of 16d, got the 11 years' time series NDVI data of Maowusu sandy land through mosaicking, projection transformation, cutting process in batch. Analysed the spatial and temporal distribution and variation characteristics of vegetation cover in year, season and month time scales by maximum value composite, and unary linear regression analysis. Then, we combined the meteorological data of 33 sites around the sandy area, analysed the response characteristics of vegetation cover change to temperature and precipitation through Pearson correlation coefficient. Studies have shown that: (1) The NDVI value has a stable increase trend, which rate is 0.0075 / a. (2) The vegetation growth have significantly difference in four seasons, the NDVI value of summer > autumn > spring > winter. (3) The NDVI value change trend is conformed to the gauss normal distribution in a year, and it comes to be largest in August, its green season is in April, and yellow season is in the middle of November, the growth period is about 220 d. (4) The vegetation has a decreasing trend from the southeast to the northwest, most part is slightly improved, and Etuokeqianqi improved significantly. (5) The correlation indexes of annual NDVI with temperature and precipitation are -0.2178 and 0.6309, the vegetation growth is mainly affected by precipitation. In this study, a complete vegetation cover analysis and evaluation model for sandy land is established. It has important guiding significance for the sand ecological environment protection.


    African Journals Online (AJOL)


    Mar 8, 2005 ... To establish the feasibility of water supply in a basement complex area ofAjaokuta, Southwestern Nigeria, pumping test results were used to investigate the storage properties and groundwater potential of the aquifer. The aquifer system consists of weathered and weathered/fractured zone of decomposed ...

  12. Cenomanian-Turonian aquifer of central Israel, its development and possible use as a storage reservoir (United States)

    Schneider, Robert


    The Cenomanian-Turonian formations constitute a highly permeable dolomite and limestone aquifer in central Israel. The aquifer is on the west limb of an anticlinorium that trends north-northeast. In places it may be as much as 800 meters thick, but in the report area, largely the foothills of the Judean-Ephraim Mountains where the water development is most intensive, its thickness is generally considerably less. In some places the aquifer occurs at or near the land surface, or it is covered by sandy and gravelly coastal-plain deposits. However, in a large part of the area, it is overlain by as much as 400 meters of relatively impermeable strata, and it is probably underlain by less permeable Lower Cretaceous strata. In general the aquifer water is under artesian pressure. The porosity of the aquifer is characterized mainly by solution channels and cavities produced by jointing and faulting. In addition to the generally high permeability of the aquifer, some regions, which probably coincide with ancient drainage patterns and (or) fault zones, have exceptionally high permeabilities. The source of most of the water in the aquifer is believed to be rain that falls on the foothills area. The westward movement of ground water from the mountainous outcrop areas appears to be impeded by a zone of low permeability which is related to structural and stratigraphic conditions along the western side of the mountains. Gradients of the piezometric surface are small, and the net direction of water movement is westward and northwestward under natural conditions. Locally, however, the flow pattern may be in other directions owing to spatial variations in permeability in the aquifer, the location of natural discharge outlets, and the relation of the aquifer to adjacent geologic formations. There probably is also a large vertical component of flow. Pumping has modified the flow pattern by producing several irregularly shaped shallow depressions in the piezometric surface although, to

  13. Comparison of dissolved and particulate arsenic distributions in shallow aquifers of Chakdaha, India, and Araihazar, Bangladesh

    Directory of Open Access Journals (Sweden)

    Ahmed Kazi M


    Full Text Available Abstract Background The origin of the spatial variability of dissolved As concentrations in shallow aquifers of the Bengal Basin remains poorly understood. To address this, we compare here transects of simultaneously-collected groundwater and aquifer solids perpendicular to the banks of the Hooghly River in Chakdaha, India, and the Old Brahmaputra River in Araihazar, Bangladesh. Results Variations in surface geomorphology mapped by electromagnetic conductivity indicate that permeable sandy soils are associated with underlying aquifers that are moderately reducing to a depth of 10–30 m, as indicated by acid-leachable Fe(II/Fe ratios 5 mg L-1. More reducing aquifers are typically capped with finer-grained soils. The patterns suggest that vertical recharge through permeable soils is associated with a flux of oxidants on the banks of the Hooghly River and, further inland, in both Chakdaha and Araihazar. Moderately reducing conditions maintained by local recharge are generally associated with low As concentrations in Araihazar, but not systematically so in Chakdaha. Unlike Araihazar, there is also little correspondence in Chakdaha between dissolved As concentrations in groundwater and the P-extractable As content of aquifer particles, averaging 191 ± 122 ug As/L, 1.1 ± 1.5 mg As kg-1 (n = 43 and 108 ± 31 ug As/L, 3.1 ± 6.5 mg As kg-1 (n = 60, respectively. We tentatively attribute these differences to a combination of younger floodplain sediments, and therefore possibly more than one mechanism of As release, as well as less reducing conditions in Chakdaha compared to Araihazar. Conclusion Systematic dating of groundwater and sediment, combined with detailed mapping of the composition of aquifer solids and groundwater, will be needed to identify the various mechanisms underlying the complex distribution of As in aquifers of the Bengal Basin.

  14. Legal Considerations for Health Care Practitioners After Superstorm Sandy. (United States)

    Hershey, Tina Batra; Van Nostrand, Elizabeth; Sood, Rishi K; Potter, Margaret


    During disaster response and recovery, legal issues often arise related to the provision of health care services to affected residents. Superstorm Sandy led to the evacuation of many hospitals and other health care facilities and compromised the ability of health care practitioners to provide necessary primary care. This article highlights the challenges and legal concerns faced by health care practitioners in the aftermath of Sandy, which included limitations in scope of practice, difficulties with credentialing, lack of portability of practitioner licenses, and concerns regarding volunteer immunity and liability. Governmental and nongovernmental entities employed various strategies to address these concerns; however, legal barriers remained that posed challenges throughout the Superstorm Sandy response and recovery period. We suggest future approaches to address these legal considerations, including policies and legislation, additional waivers of law, and planning and coordination among multiple levels of governmental and nongovernmental organizations. (Disaster Med Public Health Preparedness. 2016;10:518-524).

  15. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

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


    soil; a number of nationally red-listed species showed a similar pattern. Plant species diversity and number of red-listed species increased with slope. Where the topsoil had been acidified, limestone was rarely present above a depth of 30 cm. The presence of limestone restricts the availability......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......). Environmental variables were recorded at each plot, and soil samples were analysed for exchangeable P and N, as well as limestone content and pH. Data were analysed with regression analysis and canonical correspondence analysis. Results: Plant species richness was highest on weakly acid to slightly alkaline...

  16. Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms. (United States)

    Schwartz, Rebecca M; Gillezeau, Christina N; Liu, Bian; Lieberman-Cribbin, Wil; Taioli, Emanuela


    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 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.

  17. Hurricane Sandy, Disaster Preparedness, and the Recovery Model. (United States)

    Pizzi, Michael A


    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. Resistivity Study of Shallow Aquifers in theParts of Southern Ukanafun Local Government Area, Akwa Ibom State, Nigeria

    Directory of Open Access Journals (Sweden)

    N. J. George


    Full Text Available A resistivity study by vertical electrical sounding (VES employing the Schlumberger electrode configuration has been used to delineate shallow aquifers in some villages in Southern Ukanafun Local Government Area of Akwa Ibom State, Southern Nigeria. The information realized from the resistivity data and nearby logged boreholes show that the depths penetrated by currents were all sandy formations with various thicknesses. However, the main aquifers comprise within the maximum current penetration, very coarse – grained (gravelly sand and fine sand with resistivity in the ranges of 4680-30700 Ωm and 207-2530 Ωm and thickness in the ranges of 43-63 m and 18-40 m respectively. The aquifers with minor hydraulic gradient are separated by thin beds of clay according to lithology logs and these beds were masked in the sounding data due to the principle of suppression.

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

    Directory of Open Access Journals (Sweden)

    Ali Nejat


    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. Estimating preferential flow in karstic aquifers using statistical mixed models. (United States)

    Anaya, Angel A; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J; Meeker, John D; Alshawabkeh, Akram N


    Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models (SMMs) are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the SMMs used in the study. © 2013, National Ground Water Association.

  1. Core drilling provides information about Santa Fe Group aquifer system beneath Albuquerque's West Mesa (United States)

    Allen, B.D.; Connell, S.D.; Hawley, J.W.; Stone, B.D.


    Core samples from the upper ???1500 ft of the Santa Fe Group in the Albuquerque West Mesa area provide a first-hand look at the sediments and at subsurface stratigraphic relationships in this important part of the basin-fill aquifer system. Two major hydrostratigraphic subunits consisting of a lower coarse-grained, sandy interval and an overlying fine-grained, interbedded silty sand and clay interval lie beneath the water table at the 98th St core hole. Borehole electrical conductivity measurements reproduce major textural changes observed in the recovered cores and support subsurface correlations of hydrostratigraphic units in the Santa Fe Group aquifer system based on geophysical logs. Comparison of electrical logs from the core hole and from nearby city wells reveals laterally consistent lithostratigraphic patterns over much of the metropolitan area west of the Rio Grande that may be used to delineate structural and related stratigraphic features that have a direct bearing on the availability of ground water.

  2. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy (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...

  3. Geochemical approach of the salinization mechanisms of coastal aquifers - 14C - 226Ra chronologies

    International Nuclear Information System (INIS)

    Barbecot, F.


    Through time, coastal aquifers which constitute a great part of available fresh water resources from sedimentary basins in France, were submitted to changes in hydraulic gradients and hydrodynamic properties mainly due to discharge/recharge phases in response to sea level variations and/or anthropic forcing. Performed in the framework of the European program PALAEAUX ('Management of coastal aquifers in Europe, paleo-waters and natural controls'), this work aimed to understand the salinization process originating from the recharge/discharge conditions and recognized in three study aquifers: the calcareous Dogger aquifers along the Channel (Caen area), and the Atlantic coast (Marais Poitevin), and the Astian sandy aquifer (Cap d'Agde). Besides the conventional hydrogeological and hydrochemical methods, the main tools used are those of isotope geochemistry. For the three sites, the modern, fresh groundwaters are marked by the anthropisation of the recharge area. The evolution of isotopic signatures along a flow path depending on the mineralogy of the aquifer matrix, is linked to water-rock interactions such as cation exchange, and equilibrium with aluminosilicates. For the three study sites, the modern fresh groundwaters are marked by the anthropisation of the recharge area. The evolution of isotopic signatures along a flow path depending on the mineralogy of the aquifer matrix, is linked to water-rock interactions such as cation exchange, and equilibrium with aluminosilicates. Residence times of these fresh groundwater are from Present (Atlantic site) up to the 14 C detection limit (Channel site). Groundwater of the Astian aquifer belongs to Holocene, as determined by both 14 C and 226 Ra. From Present to 3 ka, 14 C and 226 Ra ages are coherent. Beyond, the discrepancy observed can be associated to the under-estimation of in- situ 226 Ra production, but more likely, to the 'buffer' effect of the matrix with respect to the 14 C isotopic equilibration. The salty waters

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

    African Journals Online (AJOL)

    The middle shore is primarily occupied by cirolanids and bivalves, and hippid crabs, bivalves and amphipods dominate the lower beach. Generally, species richness increases from upper to lower beach levels. Studies carried out on exposed sandy beaches of south-central Chile (ca. 40°S) show that different beach states ...

  5. Hurricane Sandy: An Educational Bibliography of Key Research Studies (United States)

    Piotrowski, Chris


    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…

  6. Structural stability and hydraulic conductivity of Nkpologu sandy ...

    African Journals Online (AJOL)


    mean weight diameter (MWD), water dispersible silt (WDSi), aggregate size distributions (> 2 mm, 1-0.5 mm and < 0.25 ... above sea level. ... and red to brownish red and derived from sandy ... where Q = steady state volume of outflow from the.

  7. Aggregations of the sandy-beach isopod, Tylos granulatus ...

    African Journals Online (AJOL)

    ... lives as a scavenger in the intertidal zone of sandy beaches on the west coast of South Africa. Individuals emerge with the receding tide leaving exit holes, then forage for about two hours before returning to the vicinity of the high-water mark where they aggregate to bury themselves, leaving behind cone-shaped mounds.

  8. effect of tractor forward speed on sandy loam soil physical ...

    African Journals Online (AJOL)

    Dr Obe

    Ilorin on a sandy loam soil to evaluate the effect of the imposition of different .... of the blade is 10.5cm. ... arranged in an inverted cone shape with ... replicates were taken for each speed run. The ..... Thakur, T. C; A. Yadav; B. P. Varshney and.

  9. Structural Stability and Hydraulic Conductivity Of Nkpologu Sandy ...

    African Journals Online (AJOL)

    Studies were conducted in the runoff plots at the University of Nigeria Nsukka Teaching and Resesarch Farm in 2010 and 2011 to monitor the changes in structural stability and saturated hydraulic conductivity (Ksat) of Nkpologu sandy loam soil under different cover management practices. The management practices were ...

  10. Can porosity affect the hyperspectral signature of sandy landscapes? (United States)

    Baranoski, Gladimir V. G.; Kimmel, Bradley W.


    Porosity is a fundamental property of sand deposits found in a wide range of landscapes, from beaches to dune fields. As a primary determinant of the density and permeability of sediments, it represents a central element in geophysical studies involving basin modeling and coastal erosion as well as geoaccoustics and geochemical investigations aiming at the understanding of sediment transport and water diffusion properties of sandy landscapes. These applications highlight the importance of obtaining reliable porosity estimations, which remains an elusive task, notably through remote sensing. In this work, we aim to contribute to the strengthening of the knowledge basis required for the development of new technologies for the remote monitoring of environmentally-triggered changes in sandy landscapes. Accordingly, we employ an in silico investigation approach to assess the effects of porosity variations on the reflectance of sandy landscapes in the visible and near-infrared spectral domains. More specifically, we perform predictive computer simulations using SPLITS, a hyperspectral light transport model for particulate materials that takes into account actual sand characterization data. To the best of our knowledge, this work represents the first comprehensive investigation relating porosity to the reflectance responses of sandy landscapes. Our findings indicate that the putative dependence of these responses on porosity may be considerably less pronounced than its dependence on other properties such as grain size and shape. Hence, future initiatives for the remote quantification of porosity will likely require reflectance sensors with a high degree of sensitivity.

  11. Rapid Assessment of Anthropogenic Impacts of Exposed Sandy ...

    African Journals Online (AJOL)

    We applied a rapid assessment methodology to estimate the degree of human impact of exposed sandy beaches in Ghana using ghost crabs as ecological indicators. The use of size ranges of ghost crab burrows and their population density as ecological indicators to assess extent of anthropogenic impacts on beaches ...

  12. Organisms associated with the sandy-beach bivalve Donax serra ...

    African Journals Online (AJOL)

    57: 134-136. BROWN, AC. & WEBB, S.c. 1994. Organisms associated \\.,.,ith burrowing whelks of the genus Bullia. S Afr. 1. Zool. 29: 144-151. BROWN, A.C., STENTON-DOZEY, J.~.E. & TRUEMAN, E.R.. 1989. Sandy-beach bivalves and gastropods; a comparison between Donax serra and Ruilia digitalis. Adv. mar. Bioi. 25:.

  13. Deaths associated with Hurricane Sandy - October-November 2012. (United States)


    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.

  14. The Sandy Hook Elementary School shooting as tipping point (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M


    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States. PMID:28228989

  15. The sandy beach meiofauna and free-living nematodes from De Panne (Belgium)


    Gheskiere, T.; Hoste, E.; Kotwicki, L.; Degraer, S.; Vanaverbeke, J.; Vincx, M.


    Despite their rather barren and arid appearance, European sandy beaches harbour a highly diverse fauna and flora and some of them are even highly productive. In contrast to tropical sandy beaches little is known about the structural and functional diversity of the different benthic components. This study aims to investigate the structural diversity of the meiobenthos, emphasizing on free-living marine nematodes on a Belgian sandy beach.The samples were collected on the sandy beach of De Panne...

  16. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land (United States)

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


    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.

  17. aquifer in ajaokuta, southwestern nigeria

    African Journals Online (AJOL)


    Mar 8, 2005 ... (1969) straight line method (observation well) of draw-down analysis in an unconfined aquifer (B=1) yield ... April) and a short wet season (May-September). .... DECOMPOSED. GRANITIC ROCK WITH. QUARTZ VEINS. 13.

  18. EPA Region 1 Sole Source Aquifers (United States)

    This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of drinking water for a given aquifer service area; that is, an aquifer which is needed to supply 50% or more of the drinking water for the area and for which there are no reasonable alternative sources should the aquifer become contaminated.The aquifers were defined by a EPA hydrogeologist. Aquifer boundaries were then drafted by EPA onto 1:24000 USGS quadrangles. For the coastal sole source aquifers the shoreline as it appeared on the quadrangle was used as a boundary. Delineated boundaries were then digitized into ARC/INFO.

  19. Sediment and discharge yields within a minimally disturbed, headwater watershed in North Central Pennsylvania, USA, with an emphasis on Superstorm Sandy (United States)

    Maloney, Kelly O.; Shull, Dustin R.


    We estimated discharge and suspended sediment (SS) yield in a minimally disturbed watershed in North Central Pennsylvania, USA, and compared a typical storm (September storm, 4.80 cm) to a large storm (Superstorm Sandy, 7.47 cm rainfall). Depending on branch, Sandy contributed 9.7–19.9 times more discharge and 11.5–37.4 times more SS than the September storm. During the September storm, the upper two branches accounted for 60.6% of discharge and 88.8% of SS at Lower Branch; during Sandy these percentages dropped to 36.1% for discharge and 30.1% for SS. The branch with close proximity roads had over two-three times per area SS yield than the branch without such roads. Hysteresis loops showed typical clockwise patterns for the September storm and more complicated patterns for Sandy, reflecting the multipeak event. Estimates of SS and hysteresis in minimally disturbed watersheds provide useful information that can be compared spatially and temporally to facilitate management.

  20. Hydrogeologic assessment of shallow clastic and carbonate rock aquifers in Hendry and Collier counties, southwestern Florida (United States)

    Brown, C. Erwin; Krulikas, R.K.; Brendle, D.L.


    Direct-current electrical resistivity data were collected from 109 vertical electrical sounding sites in Hendry and Collier Counties, southwestern Florida. Selected direct-current electrical resistivity surveys, together with available borehole geologic and geophysical data, were used to determine the approximate areal extent of the shallow clastic aquifers composed of thick sands and carbonate lithologies. Results indicated that a complex pattern of shallow sands, clays, and carbonate lithologies occur throughout the area. Buried channel sands were found as deep as 50 meters below land surface in some places. The channels contain unconsolidated fine- to medium-grained quartz sand interbedded with sandy limestone, shell fragments, and gray-green sandy clay. Both surface and borehole geophysical techniques with lithologic data were necessary to approximately locate and define layers that might behave as confining layers and to locate and define the extent of any buried sand aquifers. The borehole geophysical data were used to analyze the zones of higher resistivity. Direct-current electrical resistivity data indicated the approximate location of certain layer boundaries. The conjunctive use of natural gamma and short- and long-normal resistivity logs was helpful in determining lithologic effects. Geohydrologic sections were prepared to identify potential locations of buried channels and carbonates containing freshwater. Buried channel sands and carbonate rock sections were identified in the subsurface that potentially may contain freshwater supplies.

  1. Multi-scale nitrate transport in a sandstone aquifer system under intensive agriculture (United States)

    Paradis, Daniel; Ballard, Jean-Marc; Lefebvre, René; Savard, Martine M.


    Nitrate transport in heterogeneous bedrock aquifers is influenced by mechanisms that operate at different spatial and temporal scales. To understand these mechanisms in a fractured sandstone aquifer with high porosity, a groundwater-flow and nitrate transport model—reproducing multiple hydraulic and chemical targets—was developed to explain the actual nitrate contamination observed in groundwater and surface water in a study area on Prince Edward Island, Canada. Simulations show that nitrate is leached to the aquifer year-round, with 61% coming from untransformed and transformed organic sources originating from fertilizers and manure. This nitrate reaches the more permeable shallow aquifer through fractures in weathered sandstone that represent only 1% of the total porosity (17%). Some of the nitrate reaches the underlying aquifer, which is less active in terms of groundwater flow, but most of it is drained to the main river. The river-water quality is controlled by the nitrate input from the shallow aquifer. Groundwater in the underlying aquifer, which has long residence times, is also largely influenced by the diffusion of nitrate in the porous sandstone matrix. Consequently, following a change of fertilizer application practices, water quality in domestic wells and the river would change rapidly due to the level of nitrate found in fractures, but a lag time of up to 20 years would be necessary to reach a steady level due to diffusion. This demonstrates the importance of understanding nitrate transport mechanisms when designing effective agricultural and water management plans to improve water quality.

  2. Estimating Groundwater Mounding in Sloping Aquifers for Managed Aquifer Recharge. (United States)

    Zlotnik, Vitaly A; Kacimov, Anvar; Al-Maktoumi, Ali


    Design of managed aquifer recharge (MAR) for augmentation of groundwater resources often lacks detailed data, and simple diagnostic tools for evaluation of the water table in a broad range of parameters are needed. In many large-scale MAR projects, the effect of a regional aquifer base dip cannot be ignored due to the scale of recharge sources (e.g., wadis, streams, reservoirs). However, Hantush's (1967) solution for a horizontal aquifer base is commonly used. To address sloping aquifers, a new closed-form analytical solution for water table mound accounts for the geometry and orientation of recharge sources at the land surface with respect to the aquifer base dip. The solution, based on the Dupiuit-Forchheimer approximation, Green's function method, and coordinate transformations is convenient for computing. This solution reveals important MAR traits in variance with Hantush's solution: mounding is limited in time and space; elevation of the mound is strongly affected by the dip angle; and the peak of the mound moves over time. These findings have important practical implications for assessment of various MAR scenarios, including waterlogging potential and determining proper rates of recharge. Computations are illustrated for several characteristic MAR settings. © 2017, National Ground Water Association.

  3. Characterising aquifer treatment for pathogens in managed aquifer recharge. (United States)

    Page, D; Dillon, P; Toze, S; Sidhu, J P S


    In this study the value of subsurface treatment of urban stormwater during Aquifer Storage Transfer Recovery (ASTR) is characterised using quantitative microbial risk assessment (QMRA) methodology. The ASTR project utilizes a multi-barrier treatment train to treat urban stormwater but to date the role of the aquifer has not been quantified. In this study it was estimated that the aquifer barrier provided 1.4, 2.6, >6.0 log(10) removals for rotavirus, Cryptosporidium and Campylobacter respectively based on pathogen diffusion chamber results. The aquifer treatment barrier was found to vary in importance vis-à-vis the pre-treatment via a constructed wetland and potential post-treatment options of UV-disinfection and chlorination for the reference pathogens. The risk assessment demonstrated that the human health risk associated with potable reuse of stormwater can be mitigated (disability adjusted life years, DALYs aquifer is integrated with suitable post treatment options into a treatment train to attenuate pathogens and protect human health.

  4. Temporal changes in groundwater quality of the Saloum coastal aquifer

    Directory of Open Access Journals (Sweden)

    Ndeye Maguette Dieng


    High variation in rainfall between the 2 reference years (2003 and 2012 also changes chemical patterns in the groundwater. Chemical evolution of the groundwater is geographically observed and is due to a combination of dilution by recharge, anthropic contamination and seawater intrusion. The results of environmental isotopes (δ18O, δ2H compared with the local meteoric line indicate that the groundwater has been affected by evaporation processes before and during infiltration. The results also clearly indicate mixing with saltwater and an evolution towards relative freshening between 2003 and 2012 in some wells near the Saloum River.

  5. Sorption and Migration Mechanisms of 237 Np through Sandy Soil

    International Nuclear Information System (INIS)

    Chantaraprachoom, Nanthavan; Tanaka, Tadao


    In order to evaluate migration behavior of radioactive nuclides in the disposal of low-level radioactive waste into a shallow land burial, the sorption characteristic and migration behavior of 237 Np through sandy soil was studied. Two experimental methods were performed by using batch and column systems. The distribution coefficients (K d ) obtained from the adsorption and desorption process are rather small about 16 and 21 cm 3 /g respectively. Size distribution of 237 Np species in the influent solution was measured by ultra-filtration technique. Migration mechanism of 237 Np was studied by column experiments. The experimental condition was the influence of volume of eluting solution; 100, 300, 500, 1000 and 2000 ml respectively. The result from five column experiments confirm that the sorption characteristics of 237 Np are mainly controlled by a reversible ion-exchange reaction and the migration of 237 Np in the sandy soil can be estimated by using the K d concept

  6. Superstorm Sandy and the Verdant Power RITE Project (United States)

    Corren, D.; Colby, J.; Adonizio, M.


    On October 29, 2012 Superstorm Sandy (formerly Hurricane Sandy) made landfall in New Jersey. One of the deadliest, and second-costliest hurricane in US history, Sandy was the largest Atlantic hurricane on record, with a diameter of 1,800 km. It was this unprecedented size, extreme central low pressure, and full-moon timing that created a storm surge which inundated New York City with record-breaking water levels, resulting in tremendous destruction of buildings and infrastructure. At its RITE (Roosevelt Island Tidal Energy) Project in New York City's East River, Verdant Power has been installing demonstration and commercial turbine systems since 2005, along with performing related environmental monitoring and measurements. The RITE site is located in the East Channel of the East River, on the east side of Roosevelt Island. All along the East River, large areas of the adjacent boroughs were impacted by Sandy, including flooding of the subway tunnels under the river. When Sandy struck, Verdant had recently concluded a two-week in-water test at RITE of a new rotor for its Gen5 KHPS (Kinetic Hydropower System) turbine, with funding assistance by partners NYSERDA and the US Department of Energy. While the turbine had already been removed from its mounting in the river bottom in September, Verdant continued to operate two water measurement instruments in the river. These acoustic Doppler current profilers (ADCPs) measure the 3-D water velocity at various heights in the water column, and are also equipped to provide water level data. Verdant is interested in the effects such an extreme storm could have on turbines and other equipment installed in this river reach, as is planned by Verdant under a 10-year commercial pilot project licensed by the Federal Energy Regulatory Commission (FERC) for up to 30 turbines. Associated equipment includes navigational aids (buoys and signage), which Verdant is required to maintain to exclude vessels from the project boundaries. The East

  7. Quantifying the Digital Traces of Hurricane Sandy on Flickr (United States)

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


    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. Global assessment of coastal aquifer state and its vulnerability respect to Sea Water Intrusion. Application to several Mediterranean Coastal Aquifers. (United States)

    Baena, Leticia; Pulido-Velazquez, David; Renau-Pruñonosa, Arianna; Morell, Ignacio


    different groundwater bodies and temporal periods. Some assumptions and hypothesis assumed in this analysis of the significance of SWI were also applied in a previous research work, the SITE index (Ballesteros et al., 2016). Finally, we have also obtained vulnerability maps to SWI by applying the GALDIT method (Chachadi and Lobo-Ferreria, 2007). As in the analysis of the significance, we propose to apply an analogous procedure to summarize the vulnerability of the aquifer to SWI at different spatial scale: 2D vulnerability maps, 2D representative conceptual cross-section of the vulnerability and a global vulnerability index (L_GALDIT). The historical evolution of the L_GALDIT could be also employed to perform a global assessment of the resilience and trends of the global vulnerability of the SWI in an aquifer. While MART index is calculated using only physical variables, L_GALDIT employs weighted qualitative characteristics based on expert criteria. It can be useful to combine both MART and L_GALDIT indices in order to obtain a general knowledge of SWI in an aquifer. This research has been supported by the CGL2013-48424-C2-2-R (MINECO) project.

  9. How hydrological factors initiate instability in a model sandy slope


    Terajima, Tomomi; Miyahira, Ei-ichiro; Miyajima, Hiroyuki; Ochiai, Hirotaka; Hattori, Katsumi


    Knowledge of the mechanisms of rain-induced shallow landslides can improve the prediction of their occurrence and mitigate subsequent sediment disasters. Here, we examine an artificial slope's subsurface hydrology and propose a new slope stability analysis that includes seepage force and the down-slope transfer of excess shear forces. We measured pore water pressure and volumetric water content immediately prior to a shallow landslide on an artificial sandy slope of 32°: The direction of the ...

  10. Sandy lower Gotherivian reservoirs in the south central Turkmeniya. [Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Mavyyev, N.Ch.; Nedirov, B.R.


    Composition and capacitance-filtering properties of sandy rocks of the early Gotherivian age developed on the fields of Karadzhaulak and Cirili within the northeast slope of the Predkopetdag marginal trough and on areas of Dengli Bakharadok of the Bakharadok monocline are studied. These rocks are viewed as analogs of the gas-bearing Shatlyk level of the Murgabskiy Basin. They can be considered the main potential source of hydrocarbons on the studied territory. In the upper part of the lower Gotherivian, a level of sandy rocks is traced. Rocks represented by small-and average-grained red and light grey differences in sandstones of polymictic composition. The porosity of the sandstones is 20-22%, permeability is 200-500 mdarcy. Not only a similar stratigraphic position of the described sandstones in the lower Gotherivian was found, but also lithological common nature of the rocks. In the south central Turkmeniya one can isolate age analogs of the Shatlyk level, the main productive level of southeast Turkmeniya. The thickness of the sandy beds is from 17 to 45 m. The sandstones of the Karadzhaulak area have the best capacitance-filtering properties. Post sedimentation changes depend on the quantity and composition of the cement, influence of formation waters, and possibly thermobaric conditions of rock formation. The presence of sandy rocks with high collector properties in the cross section of the lower Gotherivian deposits in south central Turkmeniya should be considered in determining the objects for further prospecting and exploration. The areas of Kumbet and Karadzhaulak are primary.

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

    African Journals Online (AJOL)

    beaches with rdkctive and dissip:1tive characteristics (sensu. R eprodu ced by Sabin et G atew ay u n der licen ce gran ted by th e P u blish er (dated 2009). ... beach intertidal communities WaS reviewed, (b) location of len sam.!y beaches studied in south-central Chile, imd (c) location of two sandy beaches studied on the ...

  12. Localised Effects of a Mega-Disturbance: Spatiotemporal Responses of Intertidal Sandy Shore Communities to the 2010 Chilean Earthquake. (United States)

    Sepúlveda, Roger D; Valdivia, Nelson


    Determining the effects of unpredictable disturbances on dynamic ecological systems is challenged by the paucity of appropriate temporal and spatial coverage of data. On 27 February 2010, an 8.8 Mw mega-earthquake and tsunami struck central Chile and caused coastal land-level changes, massive damage to coastal infrastructure, and widespread mortality of coastal organisms. Wave-exposed sandy beaches showed significant changes of species abundances from before to after the earthquake, but the highly dynamic biotic and abiotic conditions of these habitats make difficult to draw clear-cut conclusions from these patterns. Here, we analysed a beyond-BACI (Before-After Control-Impact) sampling design to test whether the effects of the Maule earthquake on sandy-shore species diversity, abundance, and structure were heterogeneous along the shore. Invertebrate species abundances were quantified before (i.e. February 2010) and after (i.e. March 2010, September 2010, and March 2011) the earthquake at three sandy shores randomly located within the earthquake rupture area and three sites within a "control" area located >400 km southward from epicentre. Immediately after the earthquake took place, the three sites located in the rupture area showed anomalous beach-profile uplifts that did not comply with the erosion (i.e. "negative" uplifts) that regularly occurs during late summer in the region. Species richness, abundance, and community structure significantly varied from before to after the strike, but these patterns of change varied among sites within both areas. Only the site with the strongest and persistent beach-profile uplift within the rupture area showed significant concomitant changes in species richness and community structure; after 13 months, this community showed a similar multivariate structure to the before-disturbance state. This site, in particular, was located in the section of the rupture area that received most of the impact of the after-earthquake tsunami

  13. Localised Effects of a Mega-Disturbance: Spatiotemporal Responses of Intertidal Sandy Shore Communities to the 2010 Chilean Earthquake.

    Directory of Open Access Journals (Sweden)

    Roger D Sepúlveda

    Full Text Available Determining the effects of unpredictable disturbances on dynamic ecological systems is challenged by the paucity of appropriate temporal and spatial coverage of data. On 27 February 2010, an 8.8 Mw mega-earthquake and tsunami struck central Chile and caused coastal land-level changes, massive damage to coastal infrastructure, and widespread mortality of coastal organisms. Wave-exposed sandy beaches showed significant changes of species abundances from before to after the earthquake, but the highly dynamic biotic and abiotic conditions of these habitats make difficult to draw clear-cut conclusions from these patterns. Here, we analysed a beyond-BACI (Before-After Control-Impact sampling design to test whether the effects of the Maule earthquake on sandy-shore species diversity, abundance, and structure were heterogeneous along the shore. Invertebrate species abundances were quantified before (i.e. February 2010 and after (i.e. March 2010, September 2010, and March 2011 the earthquake at three sandy shores randomly located within the earthquake rupture area and three sites within a "control" area located >400 km southward from epicentre. Immediately after the earthquake took place, the three sites located in the rupture area showed anomalous beach-profile uplifts that did not comply with the erosion (i.e. "negative" uplifts that regularly occurs during late summer in the region. Species richness, abundance, and community structure significantly varied from before to after the strike, but these patterns of change varied among sites within both areas. Only the site with the strongest and persistent beach-profile uplift within the rupture area showed significant concomitant changes in species richness and community structure; after 13 months, this community showed a similar multivariate structure to the before-disturbance state. This site, in particular, was located in the section of the rupture area that received most of the impact of the after

  14. 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.

  15. Dynamics of aeolian desertification and its driving forces in the Horqin Sandy Land, Northern China. (United States)

    Duan, Han-chen; Wang, Tao; Xue, Xian; Liu, Shu-lin; Guo, Jian


    Aeolian desertification is one of the most serious environmental and socioeconomic problems in arid, semi-arid, and dry subhumid zones. Understanding desertification processes and causes is important to provide reasonable and effective control measures for preventing desertification. With satellite remote sensing images as data source to assess the temporal and spatial dynamics of desertification from 1975 to 2010 in the Horqin Sandy Land, dynamic changes of aeolian desertification were detected using the human-machine interactive interpretation method. The driving factors of local desertification were analyzed based on natural and socioeconomic data. The results show that aeolian desertified land in the study area covered 30,199 km(2) in 2010, accounting for 24.1% of the study area. The total area of aeolian desertified land obviously expanded from 30,884 km(2) in 1975 to 32,071 km(2) in 1990, and gradually decreased to 30,199 km(2) in 2010; aeolian desertified land represented an increasing trend firstly and then decreased. During the past 35 years, the gravity centers of desertified lands that are classified as extremely severe and severe generally migrated to the northeast, whereas those that are moderate and slight migrated to the northwest. The migration distance of severely desertified land was the largest, which indicated the southern desertified lands were improved during the last few decades. In addition, the climatic variation in the past 35 years has been favorable to desertification in the Horqin Sandy Land. Aeolian desertified land rapidly expanded from 1975 to 1990 under the combined effects of climate changes and unreasonable human activities. After the 1990s, the main driving factors responsible for the decrease in desertification were positive human activities, such as the series of antidesertification and ecological restoration projects.

  16. Aquifers Characterization and Productivity in Ellala Catchment ...

    African Journals Online (AJOL)


    Aquifers Characterization and Productivity in Ellala Catchment, Tigray, ... using geological and hydrogeological methods in Ellala catchment (296.5km. 2. ) ... Current estimates put the available groundwater ... Aquifer characterization takes into.

  17. Temporal reduction of the external gamma dose rate due to 137Cs mobility in sandy beaches

    International Nuclear Information System (INIS)

    Rizzotto, M.; Toso, J.; Velasco, H.; Belli, M.; Sansone, U.


    In the present paper the contribution to the external gamma dose rate due o 137 Cs in soil as a function of time is presented. Sampling sites were elected along the Calabria and Basilicata Regions coastal beaches (southern art of Italy) to assess the external gamma dose rate in air, 1 m above the round level. A convection-dispersion model, with constant parameters was sed to approximate the radiocesium soil vertical migration. The model was calibrated using the initial 137 Cs activity deposition in this region Chernobyl fallout) and 137 Cs activity concentration down the soil profile, measured 10 years later. The dispersion coefficient and the advection velocity values, were respectively: 2.17 cm 2 y -1 and 0.32 cm -1 . The Radionuclide Software Package (RSP), which uses a Monte Carlo simulation code, was used to determine the primary 137 Cs gamma dose contribution in air 1 m above the ground surface. The resulting 137 Cs external dose rate ranged from 0.42 nGy h -1 in 1986, to 0.05 nGy h -1 in 007. (author)

  18. Simultaneous counter-flow of chlorinated volatile organic compounds across the saturated-unsaturated interface region of an aquifer. (United States)

    Ronen, Daniel; Lev-Wiener, Hagit; Graber, Ellen R; Dahan, Ofer; Weisbrod, Noam


    Concentrations of chlorinated volatile organic compounds (Cl-VOCs) at the saturated-unsaturated interface region (SUIR; depth of approximately 18m) of a sandy phreatic aquifer were measured in two monitoring wells located 25m apart. The concentrations of the Cl-VOCs obtained above and below the water table along a 413-day period are interpreted to depict variable, simultaneous and independent movement of trichlorothene, tetrachloroethene, 1,1-dichloroethene, cis-1,2-dichloroethene, 1,1,1-trichloroethane, chloroform and 1,1-dichloroethane vapors in opposite directions across the SUIR. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  19. Temporal networks

    CERN Document Server

    Saramäki, Jari


    The concept of temporal networks is an extension of complex networks as a modeling framework to include information on when interactions between nodes happen. Many studies of the last decade examine how the static network structure affect dynamic systems on the network. In this traditional approach  the temporal aspects are pre-encoded in the dynamic system model. Temporal-network methods, on the other hand, lift the temporal information from the level of system dynamics to the mathematical representation of the contact network itself. This framework becomes particularly useful for cases where there is a lot of structure and heterogeneity both in the timings of interaction events and the network topology. The advantage compared to common static network approaches is the ability to design more accurate models in order to explain and predict large-scale dynamic phenomena (such as, e.g., epidemic outbreaks and other spreading phenomena). On the other hand, temporal network methods are mathematically and concept...

  20. Sensitivity of the Gravity Recovery and Climate Experiment (GRACE) to the complexity of aquifer systems for monitoring of groundwater (United States)

    Katpatal, Yashwant B.; Rishma, C.; Singh, Chandan K.


    The Gravity Recovery and Climate Experiment (GRACE) satellite mission is aimed at assessment of groundwater storage under different terrestrial conditions. The main objective of the presented study is to highlight the significance of aquifer complexity to improve the performance of GRACE in monitoring groundwater. Vidarbha region of Maharashtra, central India, was selected as the study area for analysis, since the region comprises a simple aquifer system in the western region and a complex aquifer system in the eastern region. Groundwater-level-trend analyses of the different aquifer systems and spatial and temporal variation of the terrestrial water storage anomaly were studied to understand the groundwater scenario. GRACE and its field application involve selecting four pixels from the GRACE output with different aquifer systems, where each GRACE pixel encompasses 50-90 monitoring wells. Groundwater storage anomalies (GWSA) are derived for each pixel for the period 2002 to 2015 using the Release 05 (RL05) monthly GRACE gravity models and the Global Land Data Assimilation System (GLDAS) land-surface models (GWSAGRACE) as well as the actual field data (GWSAActual). Correlation analysis between GWSAGRACE and GWSAActual was performed using linear regression. The Pearson and Spearman methods show that the performance of GRACE is good in the region with simple aquifers; however, performance is poorer in the region with multiple aquifer systems. The study highlights the importance of incorporating the sensitivity of GRACE in estimation of groundwater storage in complex aquifer systems in future studies.

  1. The trophic significance of the invasive seaweed Sargassum muticum in sandy beaches (United States)

    Rossi, Francesca; Olabarria, Celia; Incera, Mónica; Garrido, Josefina


    Native and exotic seaweeds frequently lie on the beach and sustain part of the benthic food web. However, the role of exotic seaweeds as food sources for beach consumers has been poorly studied. We studied the temporal and spatial variability in the trophic significance of the invasive brown seaweed Sargassum muticum on sandy beaches. We measured the stable isotopes ( δ13C and δ15N) in the tissues of S. muticum and of invertebrate consumers and estimated the dietary biomass proportion of S. muticum during four sampling dates at two beaches and heights on the shore. Samples were collected from eight pitfall traps placed at a distance of 2 m from each other. Detrital macroalgae and seagrasses were also collected by hand within an area of 30 cm around each pitfall trap. We measured the spatial and temporal variability in the isotope composition of the beach consumers and of S. muticum using different models of analyses of variance. We then calculated the biomass proportion of S. muticum to the animal diet with a two-isotopic mixing model. The invasive alga S. muticum seemed to be one of the main food sources for the amphipod Talitrus saltator and, to a less extent, for the isopod Tylos europaeus. The importance of S. muticum was however temporally variable and decreased during spring (in March and May), probably due to the availability of native macrophytes. The supply of invasive wrack to beach food webs thus deserves more attention if we want to understand their role in influencing food web dynamics.

  2. Preparation of Sandy Soil Stabilizer for Roads Based on Radiation Modified Polymer Composite

    International Nuclear Information System (INIS)

    Elnahas, H.H.


    Radiation modified polymer composite (RMPC) was studied to build an extremely durable sandy road, construct a trail or bath, or control dust and erosion. A dilute solution of composite binds sandy soil fines through a coagulation bonding process. The result is a dense soil structure that has superior resistance to cracks and water penetration and can also solve erosion control problems. In erosion control applications, diluted composite is merely sprayed into sandy soil without compaction, effectively sealing the surface to prevent air-born dust or deterioration from erosion. The prepared composite has an elastic and melt-able film formation that imparts thermal compacting to the stabilized sandy soil after full dryness for sandy road leveling, repairing and restoration processes. The prepared composite is environmentally economical when compared with traditional sandy soil stabilizing (SSS) or sealing methods.

  3. Aquifer thermal energy stores in Germany

    International Nuclear Information System (INIS)

    Kabus, F.; Seibt, P.; Poppei, J.


    This paper describes the state of essential demonstration projects of heat and cold storage in aquifers in Germany. Into the energy supply system of the buildings of the German Parliament in Berlin, there are integrated both a deep brine-bearing aquifer for the seasonal storage of waste heat from power and heat cogeneration and a shallow-freshwater bearing aquifer for cold storage. In Neubrandenburg, a geothermal heating plant which uses a 1.200 m deep aquifer is being retrofitted into an aquifer heat storage system which can be charged with the waste heat from a gas and steam cogeneration plant. The first centralised solar heating plant including an aquifer thermal energy store in Germany was constructed in Rostock. Solar collectors with a total area of 1000m 2 serve for the heating of a complex of buildings with 108 flats. A shallow freshwater-bearing aquifer is used for thermal energy storage. (Authors)

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


    Chauhan, Apoorva


    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, ...

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

    Directory of Open Access Journals (Sweden)

    Rebecca M. Schwartz


    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.

  6. Constraining Depositional Slope From Sedimentary Structures in Sandy Braided Streams (United States)

    Lynds, R. M.; Mohrig, D.; Heller, P. L.


    Determination of paleoslopes in ancient fluvial systems has potentially broad application to quantitatively constraining the history of tectonics and paleoclimate in continental sequences. Our method for calculating paleoslopes for sandy braided streams is based upon a simple physical model that establishes depositional skin-frictional shear stresses from assemblages of sedimentary structures and their associated grain size distributions. The addition of a skin-frictional shear stress, with a geometrically determined form-drag shear stress results in a total boundary shear stress which is directly related to water-surface slope averaged over an appropriate spatial scale. In order to apply this model to ancient fluvial systems, it is necessary to measure the following: coarsest suspended sediment size, finest grain size carried in bed load, flow depth, dune height, and dune length. In the rock record, suspended load and bed load can be accurately assessed by well-preserved suspended load deposits ("low-energy" ripples) and bed load deposits (dune foresets). This model predicts an average slope for the North Loup River near Taylor, Nebraska (modern case study) of 2.7 x 10-3. The measured reach-averaged water surface slope for the same reach of the river is 1.37 x 10-3. We suggest that it is possible to calculate the depositional slope of a sandy fluvial system by a factor of approximately two. Additionally, preliminary application of this model to the Lower Jurassic Kayenta Formation throughout the Colorado Plateau provides a promising and consistent evaluation of paleoslope in an ancient and well-preserved, sandy braided stream deposit.

  7. Disentangling diversity patterns in sandy beaches along environmental gradients. (United States)

    Barboza, Francisco R; Gómez, Julio; Lercari, Diego; Defeo, Omar


    Species richness in sandy beaches is strongly affected by concurrent variations in morphodynamics and salinity. However, as in other ecosystems, different groups of species may exhibit contrasting patterns in response to these environmental variables, which would be obscured if only aggregate richness is considered. Deconstructing biodiversity, i.e. considering richness patterns separately for different groups of species according to their taxonomic affiliation, dispersal mode or mobility, could provide a more complete understanding about factors that drive species richness patterns. This study analyzed macroscale variations in species richness at 16 Uruguayan sandy beaches with different morphodynamics, distributed along the estuarine gradient generated by the Rio de la Plata over a 2 year period. Species richness estimates were deconstructed to discriminate among taxonomic groups, supralittoral and intertidal forms, and groups with different feeding habits and development modes. Species richness was lowest at intermediate salinities, increasing towards oceanic and inner estuarine conditions, mainly following the patterns shown for intertidal forms. Moreover, there was a differential tolerance to salinity changes according to the habitat occupied and development mode, which determines the degree of sensitivity of faunal groups to osmotic stress. Generalized (additive and linear) mixed models showed a clear increase of species richness towards dissipative beaches. All taxonomic categories exhibited the same trend, even though responses to grain size and beach slope were less marked for crustaceans and insects than for molluscs or polychaetes. However, supralittoral crustaceans exhibited the opposite trend. Feeding groups decreased from dissipative to reflective systems, deposit feeders being virtually absent in the latter. This deconstructive approach highlights the relevance of life history strategies in structuring communities, highlighting the relative

  8. Estimation of the phreatic aquifer recharge of Una watershed in Taubaté, SP

    Directory of Open Access Journals (Sweden)

    Felipe Rodrigues Carbone


    Full Text Available This paper presents results related to the estimation of the phreatic aquifer recharge of the Una watershed in Taubaté, SP. The goal of this study was to develop public policies for the sustainable use of superficial and phreatic water at the Department of Agrarian Sciences of the University of Taubaté. The main results of this study are: determination of the soil physical indices, characterization of the textural profile, construction of piezometers, monitoring of the watertable, determination of the hydric climatological balance, and physic-chemical and bacteriological analyses of phreatic water. The geotechnical characterization showed that the soil have high total porosity (about 53%, and natural moisture of about 30%. Regarding the results of soil particle size measurements, it was observed that the deeper the soil the more uniform is the sediments texture distribution, varying from fine loamy, to coarse sandy. It is established a consistent relation between hydric balance and porosity, saturation and piezometric measurement in a daily historical series during one year. Methods and results allowed to calculate the phreatic aquifer discharge of several springs, that varied from 14.5 mm/day in the rainy period to 1.9 mm/day in other periods. The existence of faecal coliforms in phreatic aquifer, in variable amounts, showed that there are bacterias in the water infiltrated from septic cesspools or from the nearby Itaim River, contaminated by domestic sewage.

  9. The effects of Hurricane Sandy on trauma center admissions. (United States)

    Curran, T; Bogdanovski, D A; Hicks, A S; Bilaniuk, J W; Adams, J M; Siegel, B K; DiFazio, L T; Durling-Grover, R; Nemeth, Z H


    Hurricane Sandy was a particularly unusual storm with regard to both size and location of landfall. The storm landed in New Jersey, which is unusual for a tropical storm of such scale, and created hazardous conditions which caused injury to residents during the storm and in the months following. This study aims to describe differences in trauma center admissions and patterns of injury during this time period when compared to a period with no such storm. Data were collected for this study from patients who were admitted to the trauma center at Morristown Medical Center during Hurricane Sandy or the ensuing cleanup efforts (patients admitted between 29 October 2012 and 27 December 2012) as well as a control group consisting of all patients admitted to the trauma center between 29 October 2013 and 27 December 2013. Patient information was collected to compare the admissions of the trauma center during the period of the storm and cleanup to the control period. A total of 419 cases were identified in the storm and cleanup period. 427 were identified for the control. Striking injuries were more common in the storm and cleanup group by 266.7% (p = 0.0107); cuts were more common by 650.8% (p = 0.0044). Medical records indicate that many of these injuries were caused by Hurricane Sandy. Self-inflicted injuries were more common by 301.3% (p = 0.0294). There were no significant differences in the total number of patients, mortality, or injury severity score between the two cohorts. The data we have collected show that the conditions caused by Hurricane Sandy and the following cleanup had a significant effect on injury patterns, with more patients having been injured by being struck by falling or thrown objects, cut while using tools, or causing self-inflicted injuries. These changes, particularly during the cleanup period, are indicative of environmental changes following the storm which increase these risks of injury.

  10. Dynamic compaction with high energy of sandy hydraulic fills

    Directory of Open Access Journals (Sweden)

    Khelalfa Houssam


    Full Text Available A case study about the adoption of the dynamic compaction technique with high energy in a sandy hydraulic fill is presented. The feasibility of this technique to ensure the stability of the caisson workshop and to minimize the risk of liquefaction during manufacture. This Article is interested to establish diagnostic of dynamic compaction test, basing on the results of SPT tests and quality control as well as the details of work of compaction and the properties of filling materials. A theory of soil response to a high-energy impact during dynamic compaction is proposed.

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

    Directory of Open Access Journals (Sweden)

    Gonéri eLe Cozannet


    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

  12. Hospital emergency preparedness and response during Superstorm Sandy. (United States)


    This article presents the findings of a report by the HHS Office of Inspector General (OIG) on the performance of 172 Medicare-certified hospitals in the New York Metropolitan Area before, during, and after Sandy. It makes recommendations on how to close gaps that were found in emergency planning and execution for a disaster of this magnitude. To download the complete 40-page report and a Podcast based on it, go to reports/oei-06-13-00260. asp.

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

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.


    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.

  14. Monitoring and simulation of salinity changes in response to tide and storm surges in a sandy coastal aquifer system

    NARCIS (Netherlands)

    Huizer, S.; Karaoulis, M.C.; Oude Essink, G.H.P.; Bierkens, M.F.P.

    Tidal dynamics and especially storm surges can have an extensive impact on coastal fresh groundwater resources. Combined with the prospect of sea-level rise and the reliance of many people on these resources, this demonstrates the need to assess the vulnerability of coastal areas to these threats.

  15. A mini slug test method for determination of a local hydraulic conductivity of an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Hinsby, Klaus; Bjerg, Poul Løgstrup; Andersen, Lars J.


    distributed measurements of a local hydraulic conductivity at a tracer test site at Vejen, Denmark. The mini slug test results calculated by a modified Dax slug test analysing method, applying the elastic storativity in the Dax equations instead of the specific yield, are in good accordance with the results...

  16. Project Temporalities

    DEFF Research Database (Denmark)

    Tryggestad, Kjell; Justesen, Lise; Mouritsen, Jan


    Purpose – The purpose of this paper is to explore how animals can become stakeholders in interaction with project management technologies and what happens with project temporalities when new and surprising stakeholders become part of a project and a recognized matter of concern to be taken...... into account. Design/methodology/approach – The paper is based on a qualitative case study of a project in the building industry. The authors use actor-network theory (ANT) to analyze the emergence of animal stakeholders, stakes and temporalities. Findings – The study shows how project temporalities can...... multiply in interaction with project management technologies and how conventional linear conceptions of project time may be contested with the emergence of new non-human stakeholders and temporalities. Research limitations/implications – The study draws on ANT to show how animals can become stakeholders...

  17. Characterization of aquifer heterogeneity using Cyclostratigraphy and geophysical methods in the upper part of the Karstic Biscayne Aquifer, Southeastern Florida (United States)

    Cunningham, Kevin J.; Carlson, Janine L.; Wingard, G. Lynn; Robinson, Edward; Wacker, Michael A.


    , permeability, formation electrical conductivity, and GPR reflection amplitudes? as porosity and permeability increase, formation electrical conductivity increases and reflection amplitude decreases. This relation was observed throughout the entire vertical and lateral section of the upper part of the Biscayne aquifer in the study area. Further, upward-shallowing brackish- or freshwatercapped cycles of the upper part of the Fort Thompson Formation show low-amplitude reflections near their base that correspond to relatively higher porosity and permeability. This distribution is related to a systematic vertical stacking of rock-fabric facies within the cycle. Inferred flow characteristics of the porosity distribution within the upper part of the Biscayne aquifer were used to identify four ground-water flow classes, with each characterized by a discrete pore system that affects vertical and horizontal groundwater flow: (1) a low-permeability peat, muck, and marl ground-water flow class; (2) a horizontal conduit ground-water flow class; (3) a leaky, low-permeability ground-water flow class; and (4) a diffuse-carbonate ground-water flow class. At the top of the Biscayne aquifer, peat, muck, and marl can combine to form a relatively low-permeability layer of Holocene sediment that water moves through slowly. Most horizontal conduit flow is inferred to occur along touching vugs in portions of the following rock-fabric facies: (1) touchingvug pelecypod floatstone and rudstone, (2) sandy touching-vug pelecypod floatstone and rudstone, (3) vuggy wackestone and packstone, (4) laminated peloid grainstone and packstone, (5) peloid grainstone and packstone, and (6) peloid wackestone and packstone. Gastropod floatstone and rudstone, mudstone and wackestone, and pedogenic limestone rock-fabric facies are the main hosts for leaky, low-permeability units. This study provides evidence that the limestone that spans the base of the Miami Limestone and top of the Fort Thompson

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

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


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

  19. Effects of Barometric Fluctuations on Well Water-Level Measurements and Aquifer Test Data

    Energy Technology Data Exchange (ETDEWEB)

    FA Spane, Jr.


    The Pacific Northwest National Laboratory, as part of the Hanford Groundwater Monitoring Project, examines the potential for offsite migration of contamination within underlying aquifer systems. Well water-level elevation measurements from selected wells within these aquifer systems commonly form the basis for delineating groundwater-flow patterns (i.e., flow direction and hydraulic gradient). In addition, the analysis of water-level responses obtained in wells during hydrologic tests provides estimates of hydraulic properties that are important for evaluating groundwater-flow velocity and transport characteristics. Barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These barometric effects may lead to erroneous indications of hydraulic head within the aquifer. Total hydraulic head (i.e., sum of the water-table elevation and the atmospheric pressure at the water-table surface) within the aquifer, not well water-level elevation, is the hydrologic parameter for determining groundwater-flow direction and hydraulic gradient conditions. Temporal variations in barometric pressure may also adversely affect well water-level responses obtained during hydrologic tests. If significant, adjustments or removal of these barometric effects from the test-response record may be required for quantitative hydraulic property determination. This report examines the effects of barometric fluctuations on well water-level measurements and evaluates adjustment and removal methods for determining areal aquifer head conditions and aquifer test analysis. Two examples of Hanford Site unconfined aquifer tests are examined that demonstrate barometric response analysis and illustrate the predictive/removal capabilities of various methods for well water-level and aquifer total head values. Good predictive/removal characteristics were demonstrated with best corrective results provided by multiple-regression deconvolution methods.

  20. Building Ecological and Community Resilience and Measuring Success of the Department of Interior Hurricane Sandy Resilience Projects (United States)

    Taylor, S. M.; Worman, S. L.; Bennett, R.; Bassow, A.


    The Department of the Interior (DOI) partnered with the National Fish and Wildlife Foundation (NFWF) to administer an external funding competition to support coastal resilience projects in the region affected by Hurricane Sandy. The projects complement the DOI Bureau-led projects, but are led by state and local governments, universities, non-profits, community groups, tribes, and other non-Federal entities. In total, the Hurricane Sandy Resilience Program invested over $750 million in approximately 180 projects to repair damage and improve the resilience of habitats, communities and infrastructure to future storms and sea level rise. Project activities include waterway connection and opening, living shoreline, marsh restoration, community resilience planning, data/mapping/modeling, and beach and dune restoration. DOI and NFWF initiated a resilience assessment in 2015 to evaluate the impact of this investment. The assessment began by clarifying the program's resilience goals and the development of ecological and socio-economic metrics across the project activities. Using these metrics, the evaluation is assessing the ecological and community outcomes, cost effectiveness of activities, improved scientific understanding, and temporal and spatial scaling of benefits across resilience activities. Recognizing the unique opportunity afforded by the scale and distribution of projects, NFWF and DOI have invested in monitoring through 2024 to better understand how these projects perform over time. This presentation will describe the evaluation questions, approach, long-term monitoring, online metrics portal, and findings to date.

  1. Quality Assurance After a Natural Disaster: Lessons from Hurricane Sandy. (United States)

    Dickerson, Collin; Hsu, Yanshen; Mendoza, Sandra; Osman, Iman; Ogilvie, Jennifer; Patel, Kepal; Moreira, Andre L


    Biospecimen quality can vary depending on many pre- and post-collection variables. In this study, we consider a natural disaster as a post-collection variable that may have compromised the quality of frozen tissue specimens. To investigate this possible link, we compared the quality of nucleic acids, the level of antigenicity, and the preservation of histology from frozen specimens collected before and after the power outage caused by Hurricane Sandy. To analyze nucleic acid quality, we extracted both DNA and RNA and performed capillary electrophoresis to compare the quality and concentrations of the nucleic acids. To compare antigenicity, frozen sections were cut and immunostained for thyroid transcription factor 1 (TTF-1), a nuclear transcription protein commonly used as a diagnostic biomarker for multiple cancer types, including thyroid and lung cancers. Positive expression of TTF-1, as noted by homogenous nuclear staining, would demonstrate that the TTF-1 proteins could still bind antibodies and, therefore, that these proteins were not significantly degraded. Furthermore, representative frozen sections stained with hematoxylin and eosin were also assessed qualitatively by a trained pathologist to examine any possible histologic aberrations. Due to the similar quality of the tissue samples collected before and after the storm, Hurricane Sandy had no discernable effect on the quality of frozen specimens, and these specimens exposed to the natural disaster are still valuable research tools.

  2. Measurement of earthquake-induced shear strain in sandy gravel

    International Nuclear Information System (INIS)

    Ohkawa, I.; Futaki, M.; Yamanouchi, H.


    The nuclear power reactor buildings have been constructed on the hard rock ground formed in or before the Tertiary in Japan. This is mainly because the nuclear reactor building is much heavier than the common buildings and requires a large bearing capacity of the underlying soil deposit, and additionally the excessive deformation in soil deposit might cause damage in reactor building and subsequently cause the malfunction of the internal important facilities. Another reason is that the Quaternary soil deposit is not fully known with respect to its dynamic property. The gravel, and the sandy gravel, the representative soils of the Quaternary, have been believed to be suitable soil deposits to support the foundation of a common building, although the soils have rarely been investigated so closely on their physical properties quantitatively. In this paper, the dynamic deformability, i.e., the shear stress-strain relationship of the Quaternary diluvial soil deposit is examined through the earthquake ground motion measurement using accelerometers, pore-pressure meters, the specific devices developed in this research work. The objective soil deposit in this research is the sandy gravel of the diluvial and the alluvial

  3. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems (United States)

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


    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.

  4. Superstorm Sandy and the academic achievement of university students. (United States)

    Doyle, Matthew D; Lockwood, Brian; Comiskey, John G


    Much of the literature on the consequences of natural disasters has focused on their physical and psychological ramifications. Few researchers have considered how the impacts of a natural disaster can influence academic achievement. This study analyses data collected from nearly 300 students at a mid-sized, private university in the northeast United States to determine if the effects of Cyclone Sandy in 2012 are associated with measures of academic achievement. The findings reveal that experiencing headaches after the event resulted in a higher likelihood of students suffering a loss of academic motivation. In addition, experiencing headaches and a loss of academic motivation were correlated with a lower grade point average (GPA) during the semester in which Sandy made landfall. However, the more direct effects of the superstorm, including displacement and a loss of power, did not have a significant bearing on academic achievement. Lastly, the paper examines the implications for higher education policy and future research. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

  5. Seasonal variation in natural recharge of coastal aquifers (United States)

    Mollema, Pauline N.; Antonellini, Marco


    Many coastal zones around the world have irregular precipitation throughout the year. This results in discontinuous natural recharge of coastal aquifers, which affects the size of freshwater lenses present in sandy deposits. Temperature data for the period 1960-1990 from LocClim (local climate estimator) and those obtained from the Intergovernmental Panel on Climate Change (IPCC) SRES A1b scenario for 2070-2100, have been used to calculate the potential evapotranspiration with the Thornthwaite method. Potential recharge (difference between precipitation and potential evapotranspiration) was defined at 12 locations: Ameland (The Netherlands), Auckland and Wellington (New Zealand); Hong Kong (China); Ravenna (Italy), Mekong (Vietnam), Mumbai (India), New Jersey (USA), Nile Delta (Egypt), Kobe and Tokyo (Japan), and Singapore. The influence of variable/discontinuous recharge on the size of freshwater lenses was simulated with the SEAWAT model. The discrepancy between models with continuous and with discontinuous recharge is relatively small in areas where the total annual recharge is low (258-616 mm/year); but in places with Monsoon-dominated climate (e.g. Mumbai, with recharge up to 1,686 mm/year), the difference in freshwater-lens thickness between the discontinuous and the continuous model is larger (up to 5 m) and thus important to consider in numerical models that estimate freshwater availability.

  6. Impact of lateral flow on the transition from connected to disconnected stream-aquifer systems (United States)

    Xian, Yang; Jin, Menggui; Liu, Yanfeng; Si, Aonan


    Understanding the mechanisms by which stream water infiltrates through streambeds to recharge groundwater systems is essential to sustainable management of scarce water resources in arid and semi-arid areas. An inverted water table (IWT) can develop under a stream in response to the desaturation between the stream and underlying aquifer as the system changes from a connected to disconnected status. However, previous studies have suggested that the IWT can only occur at the bottom of a low permeability streambed in which only the vertical flow between the stream and groundwater during disconnection was assumed. In the present study, numerical simulations revealed that the lateral flow induced by capillarity or heterogeneity also plays an essential role on interactions between streams and aquifers. Three pathways were identified for the transition from connection to disconnection in homogenous systems; notably, the lowest point of an IWT can develop not only at the bottom of the streambed but also within the streambed or the aquifer in response to the initial desaturation at, above, or below the interface between the streambed and aquifer (IBSA), respectively. A sensitivity analysis indicated that in wide streams, the lowest point of an IWT only occurs at the bottom of the streambed; however, for a stream half width of 1 m above a 6 m thick sandy loam streambed, the lowest point occurs in the streambed as stream depth is less than 0.5 m. This critical stream depth increases with streambed thickness and decreases with stream width. Thus, in narrow streams the lowest point can also develop in a thick streambed under a shallow stream. In narrow streams, the lowest point also forms in the aquifer if the ratio of the hydraulic conductivity of the streambed to that of the aquifer is greater than the ratio of the streambed thickness to the sum of the stream depth and the streambed thickness; correspondingly, the streambed is thin but relatively permeable and the stream is

  7. A Coordinated USGS Science Response to Hurricane Sandy (United States)

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


    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


    Directory of Open Access Journals (Sweden)

    Anica Durău


    Full Text Available Climatic conditions in the sandy soils of southern Oltenia encourage cultivation of tree species in terms of applying specific technologies. Possibility of poor sandy soils fertile capitalization, earliness in 7- 10 days of fruit ripening , high yields and quality are the main factors supporting the development of fruit growing in the sandy soils of southern Oltenia. The main objectives of the research were to CCDCPN Dăbuleni. Establish and improve stone fruit species assortment, adapted to the stress of the sandy soils, establishment and evaluation of the influence of stress on trees and their influence on the size and quality of production, development of technological links (planting distances, forms management, fertilization, getting high and consistent annual production of high quality, containing low as pesticide residues, to establish a integrated health control program of the trees with emphasis on biotechnical. Research has shown good stone species behavior, and their recommended proportion is 75% of all fruit trees (peach 36%, 14% apricot, plum15%, sweet and sour cherry fruit growing 10% of the total area. Results on peach varieties revealed: ’Redhaven’, ’Suncrest’, ’Loring’ with yields ranging from (24.8 t / ha to 29.0 t/ha with maturation period from July to August, and varieties ’NJ 244’, ’Fayette’, ’Flacara’ with productions ranging from (19.7 t / ha to 23.0 t/ha with maturation period from August to September. The sweet cherry varieties ’Van’, ’Rainier’, ’Stella’, with yields ranging from 17. 2 to 24.4 t / ha. In the range studied sour cherry were found ’Oblacinska’ varieties of 11.0 t / ha, ’Cernokaia’ with 10.5 t / ha, ’Schatten Morelle’ with 9.1 t / ha. Optimum planting density and shape of the peach crown found that the highest yields of fruit are produced in the form of vertical cordon crown, with values ranging from 15.9 t / ha at a distance of 2 m, 10.3 t / ha at a distance

  9. Estimation of uranium migration parameters in sandstone aquifers. (United States)

    Malov, A I


    The chemical composition and isotopes of carbon and uranium were investigated in groundwater samples that were collected from 16 wells and 2 sources in the Northern Dvina Basin, Northwest Russia. Across the dataset, the temperatures in the groundwater ranged from 3.6 to 6.9 °C, the pH ranged from 7.6 to 9.0, the Eh ranged from -137 to +128 mV, the total dissolved solids (TDS) ranged from 209 to 22,000 mg L(-1), and the dissolved oxygen (DO) ranged from 0 to 9.9 ppm. The (14)C activity ranged from 0 to 69.96 ± 0.69 percent modern carbon (pmC). The uranium content in the groundwater ranged from 0.006 to 16 ppb, and the (234)U:(238)U activity ratio ranged from 1.35 ± 0.21 to 8.61 ± 1.35. The uranium concentration and (234)U:(238)U activity ratio increased from the recharge area to the redox barrier; behind the barrier, the uranium content is minimal. The results were systematized by creating a conceptual model of the Northern Dvina Basin's hydrogeological system. The use of uranium isotope dating in conjunction with radiocarbon dating allowed the determination of important water-rock interaction parameters, such as the dissolution rate:recoil loss factor ratio Rd:p (a(-1)) and the uranium retardation factor:recoil loss factor ratio R:p in the aquifer. The (14)C age of the water was estimated to be between modern and >35,000 years. The (234)U-(238)U age of the water was estimated to be between 260 and 582,000 years. The Rd:p ratio decreases with increasing groundwater residence time in the aquifer from n × 10(-5) to n × 10(-7) a(-1). This finding is observed because the TDS increases in that direction from 0.2 to 9 g L(-1), and accordingly, the mineral saturation indices increase. Relatively high values of R:p (200-1000) characterize aquifers in sandy-clayey sediments from the Late Pleistocene and the deepest parts of the Vendian strata. In samples from the sandstones of the upper part of the Vendian strata, the R:p value is ∼ 24, i.e., sorption processes are

  10. Arsenic, microbes and contaminated aquifers (United States)

    Oremland, Ronald S.; Stolz, John F.


    The health of tens of millions of people world-wide is at risk from drinking arsenic-contaminated well water. In most cases this arsenic occurs naturally within the sub-surface aquifers, rather than being derived from identifiable point sources of pollution. The mobilization of arsenic into the aqueous phase is the first crucial step in a process that eventually leads to human arsenicosis. Increasing evidence suggests that this is a microbiological phenomenon.

  11. 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.


    The fate of nitrogen from N-15-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha(-1) was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L...... 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...... was applied to growing ryegrass at the sandy loam soil, the immobilization of urine-derived N was significantly reduced compared to application prior to sowing. The results indicated that the net mineralization of urine N was similar to that of urea in the sandy soil, but only about 75% of the urine N was net...

  12. Aquifer thermal-energy-storage modeling (United States)

    Schaetzle, W. J.; Lecroy, J. E.


    A model aquifer was constructed to simulate the operation of a full size aquifer. Instrumentation to evaluate the water flow and thermal energy storage was installed in the system. Numerous runs injecting warm water into a preconditioned uniform aquifer were made. Energy recoveries were evaluated and agree with comparisons of other limited available data. The model aquifer is simulated in a swimming pool, 18 ft by 4 ft, which was filled with sand. Temperature probes were installed in the system. A 2 ft thick aquifer is confined by two layers of polyethylene. Both the aquifer and overburden are sand. Four well configurations are available. The system description and original tests, including energy recovery, are described.

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

    NARCIS (Netherlands)

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


    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

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

    DEFF Research Database (Denmark)

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


    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...

  15. 33 CFR 80.170 - Sandy Hook, NJ to Tom's River, NJ. (United States)


    ... 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...

  16. 77 FR 74891 - Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy (United States)


    ... Client Update on Superstorm Sandy--Current and Ongoing Operations as Markets Re-Open; Physical.../downloads/legal/imp_notices/2012/dtcc/z0033.pdf ; ``DTCC Client Update on Superstorm Sandy--Physical...:// ; ``DTCC Client Update on Superstorm...

  17. 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.


    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

  18. Salt Marsh Monitoring in Jamaica Bay, New York from 2003 to 2013: A Decade of Change from Restoration to Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Anthony Campbell


    Full Text Available This study used Quickbird-2 and Worldview-2, high resolution satellite imagery, in a multi-temporal salt marsh mapping and change analysis of Jamaica Bay, New York. An object-based image analysis methodology was employed. The study seeks to understand both natural and anthropogenic changes caused by Hurricane Sandy and salt marsh restoration, respectively. The objectives of this study were to: (1 document salt marsh change in Jamaica Bay from 2003 to 2013; (2 determine the impact of Hurricane Sandy on salt marshes within Jamaica Bay; (3 evaluate this long term monitoring methodology; and (4 evaluate the use of multiple sensor derived classifications to conduct change analysis. The study determined changes from 2003 to 2008, 2008 to 2012 and 2012 to 2013 to better understand the impact of restoration and natural disturbances. The study found that 21 ha of salt marsh vegetation was lost from 2003 to 2013. From 2012 to 2013, restoration efforts resulted in an increase of 10.6 ha of salt marsh. Hurricane Sandy breached West Pond, a freshwater environment, causing 3.1 ha of freshwater wetland loss. The natural salt marsh showed a decreasing trend in loss. Larger salt marshes in 2012 tended to add vegetation in 2012–2013 (F4,6 = 13.93, p = 0.0357 and R2 = 0.90. The study provides important information for the resource management of Jamaica Bay.

  19. Characterization of recharge processes in shallow and deeper aquifers using isotopic signatures and geochemical behavior of groundwater in an arsenic-enriched part of the Ganga Plain

    International Nuclear Information System (INIS)

    Saha, Dipankar; Sinha, U.K.; Dwivedi, S.N.


    Research highlights: → Sub-regional scale aquifers delineated in arsenic-enriched belt in the Ganga Plain. Isotopic fingerprint of the groundwater, from arsenic-enriched and arsenic-safe aquifers established for the first time in the Ganga Plain. → Recharge processes and the water provenances of vertically separated Quaternary aquifers have been established. → Mean residence time of groundwater in the deeper aquifers has been worked out using C-14 isotope. → Water from the deeper aquifer has been correlated with the paleoclimatic model of the Middle Ganga Plain (Mid-Ganga Basin) for 6-2 ka. - Abstract: Arsenic concentrations in groundwater extracted from shallow aquifers in some areas of the Ganga Plain in the states of Bihar and Uttar Pradesh, exceed 50 μg L -1 and locally reach levels in the 400 μg L -1 range. The study covered 535 km 2 of active flood plain of the River Ganga, in Bihar where a two-tier aquifer system has been delineated in a multi-cyclic sequence of Quaternary sand, clay, sandy clay and silty clay all ≤∼250 m below ground surface. The research used isotopic signatures (δ 18 O, δ 2 Η, 3 H, 14 C) and major chemical constituents (HCO 3 - ,SO 4 2- ,NO 3 - ,Cl - ,Ca 2+ ,Mg 2+ ,Na + ,K + ,As total ) of groundwater to understand the recharge processes and groundwater circulation in the aquifers. Values of δ 18 O and δ 2 Η combined with 3 H data indicate that the recharge to the As-enriched top 40 m of the deposits is modern ( -1 ) is hydrologically isolated from the upper aquifer and is characterized by lower 14 C concentration and lower (more negative) δ 18 O values. Groundwater in the lower aquifer is ∼3 ka old, occurs under semi-confined to confined conditions, with hydrostatic head at 1.10 m above the head of the upper aquifer during the pre-monsoon. The recharge areas of the lower aquifer lies in Pleistocene deposits in basin margin areas with the exposed Vindhyan System, at about 55 km south of the area.

  20. Hydrochemistry of New Zealand's aquifers

    International Nuclear Information System (INIS)

    Rosen, M.R.


    Groundwater chemistry on a national scale has never been studied in New Zealand apart from a few studies on nitrate concentrations and pesticides. These studies are covered in Chapter 8 of this book. However general studies of groundwater chemistry, groundwater-rock interaction and regional characteristics of water quality have not been previously addressed in much detail. This is partly because New Zealand aquifers are relatively small on a world scale and are geologically and tectonically diverse (see Chapter 3). But New Zealand has also recently lacked a centralised agency responsible for groundwater quality, and therefore, no national assessments have been undertaken. In recent years, the Institute of Geological and Nuclear Sciences has managed a programme of collecting and analysing the groundwater chemistry of key New Zealand aquifers. This programme is called the National Groundwater Monitoring Programme (NGMP) and is funded by the New Zealand Public Good Science Fund. The programme started in 1990 using only 22 wells, with four regional authorities of the country participating. The NGMP now includes all 15 regional and unitary authorities that use groundwater and over 100 monitoring sites. The NGMP is considered a nationally significant database by the New Zealand Foundation for Research Science and Technology. The NGMP allows a national comparison of aquifer chemistries because the samples are all analysed at one laboratory in a consistent manner and undergo stringent quality control checks. Poor quality analyses are thus minimised. In addition, samples are collected quarterly so that long-term seasonal trends in water quality can be analysed, and the effects of changes in land use and the vulnerability of aquifers to contaminant leaching can be assessed. This chapter summarises the water quality data collected for the NGMP over the past 10 years. Some records are much shorter than others, but most are greater than three years. Additional information is

  1. Attenuation of contaminant plumes in homogeneous aquifers: Sensitivity to source function at moderate to large peclet numbers

    International Nuclear Information System (INIS)

    Selander, W.N.; Lane, F.E.; Rowat, J.H.


    A groundwater mass transfer calculation is an essential part of the performance assessment for radioactive waste disposal facilities. AECL's IRUS (Intrusion Resistant Underground Structure) facility, which is designed for the near-surface disposal of low-level radioactive waste (LLRW), is to be situated in the sandy overburden at AECL's Chalk River Laboratories. Flow in the sandy aquifers at the proposed IRUS site is relatively homogeneous and advection-dominated (large Peclet numbers). Mass transfer along the mean direction of flow from the IRUS site may be described using the one-dimensional advection-dispersion equation, for which a Green's function representation of downstream radionuclide flux is convenient. This report shows that in advection-dominated aquifers, dispersive attenuation of initial contaminant releases depends principally on two time scales: the source duration and the pulse breakthrough time. Numerical investigation shows further that the maximum downstream flux or concentration depends on these time scales in a simple characteristic way that is minimally sensitive to the shape of the initial source pulse. (author). 11 refs., 2 tabs., 3 figs

  2. Assessing the recharge of a coastal aquifer using physical observations, tritium, groundwater chemistry and modelling. (United States)

    Santos, Isaac R; Zhang, Chenming; Maher, Damien T; Atkins, Marnie L; Holland, Rodney; Morgenstern, Uwe; Li, Ling


    Assessing recharge is critical to understanding groundwater and preventing pollution. Here, we investigate recharge in an Australian coastal aquifer using a combination of physical, modelling and geochemical techniques. We assess whether recharge may occur through a pervasive layer of floodplain muds that was initially hypothesized to be impermeable. At least 59% of the precipitation volume could be accounted for in the shallow aquifer using the water table fluctuation method during four significant recharge events. Precipitation events rates were estimated in the area underneath the floodplain clay layer rather than in the sandy area. A steady-state chloride method implied recharge rates of at least 200mm/year (>14% of annual precipitation). Tritium dating revealed long term net vertical recharge rates ranging from 27 to 114mm/year (average 58mm/year) which were interpreted as minimum net long term recharge. Borehole experiments revealed more permeable conditions and heterogeneous infiltration rates when the floodplain soils were dry. Wet conditions apparently expand floodplain clays, closing macropores and cracks that act as conduits for groundwater recharge. Modelled groundwater flow paths were consistent with tritium dating and provided independent evidence that the clay layer does not prevent local recharge. Overall, all lines of evidence demonstrated that the coastal floodplain muds do not prevent the infiltration of rainwater into the underlying sand aquifer, and that local recharge across the muds was widespread. Therefore, assuming fine-grained floodplain soils prevent recharge and protect underlying aquifers from pollution may not be reasonable. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. An evaluation of aquifer intercommunication between the unconfined and Rattlesnake Ridge aquifers on the Hanford Site

    International Nuclear Information System (INIS)

    Jensen, E.J.


    During 1986, Pacific Northwest Laboratory conducted a study of a portion of the Rattlesnake Ridge aquifer (confined aquifer) that lies beneath the B Pond - Gable Mountain Pond area of the Hanford Site. The purpose was to determine the extent of intercommunication between the unconfined aquifer and the uppermost regionally extensive confined aquifer, referred to as the Rattlesnake Ridge aquifer. Hydraulic head data and chemical data were collected from the ground water in the study area during December 1986. The hydraulic head data were used to determine the effects caused by water discharged to the ground from B Pond on both the water table of the unconfined aquifer and the potentiometric surface of the confined aquifer. The chemical data were collected to determine the extent of chemical constituents migrating from the unconfined aquifer to the confined aquifer. Analysis of chemical constituents in the Rattlesnake Ridge aquifer demonstrated that communication between the unconfined and confined aquifers had occurred. However, the levels of contaminants found in the Rattlesnake Ridge aquifer during this study were below the DOE Derived Concentration Guides

  4. Aquifer Characterization and Groundwater Potential Assessment

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Keywords: Aquifer Characterization, Groundwater Potential, Electrical Resistivity, Lithologic Logs ... State Water Corporation currently cannot meet the daily water ... METHOD OF STUDY ... sections which were constrained with the available.

  5. Morphodynamic Impacts of Hurricane Sandy on the Inner-shelf (Invited) (United States)

    Trembanis, A. C.; Beaudoin, J. D.; DuVal, C.; Schmidt, V. E.; Mayer, L. A.


    Through the careful execution of precision high-resolution acoustic sonar surveys over the period of October 2012 through July 2013, we have obtained a unique set of high-resolution before and after storm measurements of seabed morphology and in situ hydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the 'Redbird reef' (Raineault et al., 2013). Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. In order to understand and characterize the ripple dynamics and scour processes in an energetic, heterogeneous inner-shelf setting, a series of high-resolution geoacoustic surveys were conducted before and after Hurricane Sandy. Our overall goal is to improve our understanding of bedform dynamics and spatio-temporal length scales and defect densities through the application of a recently developed fingerprint algorithm technique (Skarke and Trembanis, 2011). Utilizing high-resolution swath sonar collected by an AUV and from surface vessel multibeam sonar, our study focuses both on bedforms in the vicinity of manmade seabed objects (e.g. shipwrecks and subway cars) and dynamic natural ripples on the inner-shelf in energetic coastal settings with application to critical military operations such as mine countermeasures. Seafloor mapping surveys were conducted both with a ship-mounted multibeam echosounder (200 kHz and 400 kHz) and an Autonomous Underwater Vehicle (AUV) configured with high-resolution side-scan sonar (900 and 1800 kHz) and a phase measuring bathymetric sonar (500 kHz). These geoacoustic surveys were further augmented with data collected by in situ instruments placed on the seabed that recorded measurements of waves and currents at the site before, during, and after the storm. Multibeam echosounder map of

  6. Fractal analysis of the hydraulic conductivity on a sandy porous media reproduced in a laboratory facility. (United States)

    de Bartolo, S.; Fallico, C.; Straface, S.; Troisi, S.; Veltri, M.


    The complexity characterization of the porous media structure, in terms of the "pore" phase and the "solid" phase, can be carried out by means of the fractal geometry which is able to put in relationship the soil structural properties and the water content. It is particularly complicated to describe analytically the hydraulic conductivity for the irregularity of the porous media structure. However these can be described by many fractal models considering the soil structure as the distribution of particles dimensions, the distribution of the solid aggregates, the surface of the pore-solid interface and the fractal mass of the "pore" and "solid" phases. In this paper the fractal model of Yu and Cheng (2002) and Yu and Liu (2004), for a saturated bidispersed porous media, was considered. This model, using the Sierpinsky-type gasket scheme, doesn't contain empiric constants and furnishes a well accord with the experimental data. For this study an unconfined aquifer was reproduced by means of a tank with a volume of 10 Ã- 7 Ã- 3 m3, filled with a homogeneous sand (95% of SiO2), with a high percentage (86.4%) of grains between 0.063mm and 0.125mm and a medium-high permeability. From the hydraulic point of view, 17 boreholes, a pumping well and a drainage ring around its edge were placed. The permeability was measured utilizing three different methods, consisting respectively in pumping test, slug test and laboratory analysis of an undisturbed soil cores, each of that involving in the measurement a different support volume. The temporal series of the drawdown obtained by the pumping test were analyzed by the Neuman-type Curve method (1972), because the saturated part above the bottom of the facility represents an unconfined aquifer. The data analysis of the slug test were performed by the Bouwer & Rice (1976) method and the laboratory analysis were performed on undisturbed saturated soil samples utilizing a falling head permeameter. The obtained values either of the

  7. Water Infiltration and Hydraulic Conductivity in Sandy Cambisols

    DEFF Research Database (Denmark)

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


    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...... of the experimental soils. The results indicate clearly that soils play a crucial role for water retention and therefore, in overland flow prevention. There is a need to have more awareness on the intimate link between the land use and soil properties and their possible effects on flooding.......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...

  8. 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.

  9. Hurricane Sandy: Shared Trauma and Therapist Self-Disclosure. (United States)

    Rao, Nyapati; Mehra, Ashwin


    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.

  10. Performance of Social Network Sensors during Hurricane Sandy (United States)

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


    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

  11. Estimating energy fluxes within the stream-aquifer interface of the Avenelles basin (United States)

    Berrhouma, Asma; Rivière, Agnès; Goblet, Patrick; Cucchi, Karina; Rubin, Yoram; Baudin, Aurélien; Ansart, Patrick; Flipo, Nicolas


    The understanding of water temperature evolution and its associated energy fluxes is important to follow the aquatic habitats evolution and to predict future modifications induced by climate change. The spatio-temporal energy balance dynamics within the stream-aquifer interface is complex because of the multitude of physical, morphological and meteorological parameters on which it depends. This critical interface is involving numerous physical and bio-geochemical processes which are taking place at different time and spatial scales. The energy balance estimation at this interface depends mainly on the direction, magnitude and variability of water exchanges and the temporal variation of river and aquifer temperatures as well as the thermal porous media properties. In this work, a combined numerical and experimental approach is used to study the temporal and spatial evolution of the energy budget along 6 km of the stream network of the Avenelles watershed. With an area of 46 km2, the Avenelles watershed is located 70 km east from Paris. The Avenelles river presents different types of connectivity with the underlying aquifers. Five Local Monitoring Stations (LOMOS) have been deployed along the hydraulic corridor to monitor the water and thermal exchanges between the stream and aquifer over years, based on continuous pressure and temperature measurements in the river, the hyporheic zone (HZ) and the underlying aquifer. A 2D finite element thermo-hydrogeological model (METIS) coupled with a parameters screening script is used to determine the hydrogeological and thermal properties of the HZ and of the underlying aquifers by inversion at five LOMOS. Once the local models are calibrated, water and heat fluxes through the stream - aquifer interface are assessed over years (2012-2015) along the stream network. This work offers a new understanding of the stream-aquifer interface functioning, shifting from a pure hydrological characterizing toward a more subtle view that

  12. A long-term bench-scale investigation of permanganate consumption by aquifer materials. (United States)

    Xu, Xiuyuan; Thomson, Neil R


    In situ chemical oxidation (ISCO) applications using permanganate involve the injection or release of permanganate into the subsurface to destroy various target contaminants. Naturally occurring reduced components associated with aquifer materials can exert a significant oxidant demand thereby reducing the amount of permanganate available for the destruction of contaminants as well as reducing the overall rate of oxidation. Quantification of this natural oxidant demand (NOD) is a requirement for site-specific assessment and the design of cost-effective oxidant delivery systems. To further our understanding of the interaction between permanganate and aquifer materials, aerobic and anaerobic aquifer materials from eight representative sites throughout North America were tested in a series of systematic bench-scale experiments. Various permanganate to aquifer solids mass loading ratios at different initial permanganate concentrations in well-mixed batch reactors were monitored for >300 days. All NOD temporal profiles demonstrated an initial fast consumption rate followed by a persistent slower consumption rate. The data generated show that the mass loading ratio, the initial permanganate concentration, and the nature and quantity of reduced aquifer material species are the main factors controlling permanganate consumption rates. A higher initial permanganate concentration or a larger mass loading ratio produced a larger fast NOD consumption rate and generated a corresponding higher maximum NOD value. Hence, both the NOD temporal profile and the maximum NOD are not single-valued but are heavily dependent on the experimental conditions. Predictive relationships were developed to estimate the maximum NOD and the NOD at 7 days based on aquifer material properties. The concentration of manganese oxides deposited on the aquifer solids was highly correlated with the mass of permanganate consumed suggesting that passivation of NOD reaction sites occurred due to the formation

  13. Phosphorus distribution in sandy soil profile under drip irrigation system

    International Nuclear Information System (INIS)

    El-Gendy, R.W.; Rizk, M.A.; Abd El Moniem, M.; Abdel-Aziz, H.A.; Fahmi, A.E.


    This work aims at to studying the impact of irrigation water applied using drip irrigation system in sandy soil with snap bean on phosphorus distribution. This experiment was carried out in soils and water research department farm, nuclear research center, atomic energy authority, cairo, Egypt. Snap bean was cultivated in sandy soil and irrigated with 50,37.5 and 25 cm water in three water treatments represented 100, 75 and 50% ETc. Phosphorus distribution and direction of soil water movement had been detected in three sites on the dripper line (S1,S2 and S3 at 0,12.5 and 25 cm distance from dripper). Phosphorus fertilizer (super phosphate, 15.5% P 2 O 5 in rate 300 kg/fed)was added before cultivation. Neutron probe was used to detect the water distribution and movement at the three site along soil profile. Soil samples were collected before p-addition, at end developing, mid, and late growth stages to determine residual available phosphorus. The obtained data showed that using 50 cm water for irrigation caused an increase in P-concentration till 75 cm depth in the three sites of 100% etc treatment, and covered P-requirements of snap bean for all growth stages. As for 37.5 and 25 cm irrigation water cannot cover all growth stages for P-requirements of snap bean. It could be concluded that applied irrigation water could drive the residual P-levels till 75 cm depth in the three sites. Yield of the crop had been taken as an indicator as an indicator profile. Yield showed good response according to water quantities and P-transportation within the soil profile

  14. 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.

  15. Temporal networks (United States)

    Holme, Petter; Saramäki, Jari


    A great variety of systems in nature, society and technology-from the web of sexual contacts to the Internet, from the nervous system to power grids-can be modeled as graphs of vertices coupled by edges. The network structure, describing how the graph is wired, helps us understand, predict and optimize the behavior of dynamical systems. In many cases, however, the edges are not continuously active. As an example, in networks of communication via e-mail, text messages, or phone calls, edges represent sequences of instantaneous or practically instantaneous contacts. In some cases, edges are active for non-negligible periods of time: e.g., the proximity patterns of inpatients at hospitals can be represented by a graph where an edge between two individuals is on throughout the time they are at the same ward. Like network topology, the temporal structure of edge activations can affect dynamics of systems interacting through the network, from disease contagion on the network of patients to information diffusion over an e-mail network. In this review, we present the emergent field of temporal networks, and discuss methods for analyzing topological and temporal structure and models for elucidating their relation to the behavior of dynamical systems. In the light of traditional network theory, one can see this framework as moving the information of when things happen from the dynamical system on the network, to the network itself. Since fundamental properties, such as the transitivity of edges, do not necessarily hold in temporal networks, many of these methods need to be quite different from those for static networks. The study of temporal networks is very interdisciplinary in nature. Reflecting this, even the object of study has many names-temporal graphs, evolving graphs, time-varying graphs, time-aggregated graphs, time-stamped graphs, dynamic networks, dynamic graphs, dynamical graphs, and so on. This review covers different fields where temporal graphs are considered

  16. 78 FR 7780 - Sunshine Act Meeting; FCC Announces Further Details for the First Post-Superstorm Sandy Field... (United States)


    ... First Post-Superstorm Sandy Field Hearing, Tuesday, February 5, 2013 AGENCY: Federal Communications Commission. ACTION: Sunshine notice. SUMMARY: In the wake of Superstorm Sandy, Federal Communications... focusing on the impact of Superstorm Sandy, and help inform recommendations and actions to strengthen wired...

  17. Geohydrology and water quality of the North Platte River alluvial aquifer, Garden County, Western Nebraska (United States)

    Steele, Gregory V.; Cannia, James C.


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

  18. Understanding Kendal aquifer system: a baseline analysis for sustainable water management proposal (United States)

    Lukman, A.; Aryanto, M. D.; Pramudito, A.; Andhika, A.; Irawan, D. E.


    North coast of Java has been grown as the center of economic activities and major connectivity hub for Sumatra and Bali. Sustainable water management must support such role. One of the basis is to understand the baseline of groundwater occurrences and potential. However the complex alluvium aquiver system has not been well-understood. A geoelectric measurements were performed to determine which rock layer has a good potential as groundwater aquifers in the northern coast of Kaliwungu Regency, Kendal District, Central Java province. Total of 10 vertical electrical sounding (VES) points has been performed, using a Schlumberger configuration with the current electrode spacing (AB/2) varies between 200 - 300 m and the potential difference electrode spacing (MN/2) varies between 0.5 to 20 m with depths target ranging between 150 - 200 m. Geoelectrical data processing is done using Ip2win software which generates resistivity value, thickness and depth of subsurface rock layers. Based on the correlation between resistivity value with regional geology, hydrogeology and local well data, we identify three aquifer layers. The first layer is silty clay with resistivity values vary between 0 - 10 ohm.m, then the second layer is tuffaceous claystone with resistivity value between 10 - 60 ohm.m. Both layers serve as impermeable layer. The third layer is sandy tuff with resistivity value between 60 - 100 ohm.m which serves as a confined aquifer layer located at 70 - 100 m below surface. Its thickness is vary between 70 to 110 m. The aquifer layer is a mixing of volcanic and alluvium sediment, which is a member of Damar Formation. The stratification of the aquifer system may change in short distance and depth. This natural setting prevent us to make a long continuous correlation between layers. Aquifer discharge is estimated between 5 - 71 L/s with the potential deep well locations lies in the west and southeast part of the study area. These hydrogeological settings should be used

  19. Water-quality observations of the San Antonio segment of the Edwards aquifer, Texas, with an emphasis on processes influencing nutrient and pesticide geochemistry and factors affecting aquifer vulnerability, 2010–16 (United States)

    Opsahl, Stephen P.; Musgrove, MaryLynn; Mahler, Barbara J.; Lambert, Rebecca B.


    concentrations. The continuum of water quality from unconfined rural groundwater sites (least affected by anthropogenic contamination) to unconfined urban groundwater sites (most affected by anthropogenic contamination) demonstrates enhanced vulnerability of urban versus rural land cover. Differences in contaminant occurrences and concentration among unconfined urban wells indicate that the urban parts of the aquifer are not uniformly vulnerable, but rather are affected by spatial differences in the sources of nutrients and pesticides. In urban areas, the shallow, unconfined groundwater sites showed greater temporal variability in both nutrient and pesticide concentrations, as well as a greater degree of contamination, than did deeper, confined groundwater sites. In comparison to that of the shallow, unconfined groundwater sites, the water quality of the deeper, confined groundwater sites was relatively invariant during this multiyear study. Although aquifer hydrogeology is an important factor related to aquifer vulnerability, land cover likely has a greater influence on pesticide contamination of groundwater. Temporal variability in hydrologic conditions for the Edwards aquifer is apparent in data for surface water as a source of groundwater recharge, water-level altitude in wells, spring discharge, and groundwater quality. This temporal variability affects recharge sources, recharge amounts, groundwater traveltimes, flow routing, water-rock interaction processes, dilution, mixing, and, in turn, water quality. Relations of land cover, aquifer hydrogeology, and changing hydrologic conditions to water quality are complex but provide insight into the vulnerability of Edwards aquifer groundwater—a vital drinking-water resource.

  20. Diagnosis of the Ghiss Nekor aquifer in order to elaborate the aquifer contract (United States)

    Baite, Wissal; Boukdir, A.; Zitouni, A.; Dahbi, S. D.; Mesmoudi, H.; Elissami, A.; Sabri, E.; Ikhmerdi, H.


    The Ghiss-Nekor aquifer, located in the north-east of the action area of the ABHL, plays a strategic role in the drinkable water supply of the city of Al Hoceima and of the neighboring urban areas. It also participates in the irrigation of PMH. However, this aquifer has problems such as over-exploitation and pollution. In the face of these problems, the only Solution is the establishment of a new mode of governance, which privileges the participation, the involvement and the responsibility of the actors concerned in a negotiated contractual framework, namely the aquifer contract. The purpose of this study is to diagnose the current state of the Ghiss Nekor aquifer, the hydrogeological characterization of the aquifer, the use of the waters of the aquifer, the Problem identification and the introduction of the aquifer contract, which aims at the participatory and sustainable management of underground water resources in the Ghiss- Nekor plain, to ensure sustainable development.

  1. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez R, J.; de la Pena L, A.


    The most recent information on the Cerro Prieto geothermal aquifer is summarized, with special emphasis on the initial production zone where the wells completed in the Alpha aquifer are located. These wells produce steam for power plant units 1 and 2. Brief comments also are made on the Beta aquifer, which underlies the Alpha aquifer in the Cerro Prieto I area and which extends to the east to what is known as the Cerro Prieto II and Cerro Prieto III areas. The location of the area studied is shown. The Alpha and Beta aquifers differ in their mineralogy and cementing mineral composition, temperatures, and piezometric levels. The difference in piezometric levels indicates that there is no local communication between the two aquifers. This situation has been verified by a well interference test, using well E-1 as a producer in the Beta aquifer and well M-46 as the observation well in the Alpha aquifer. No interference between them was observed. Information on the geology, geohydrology, and geochemistry of Cerro Prieto is presented.

  2. Estimating Aquifer Properties Using Sinusoidal Pumping Tests (United States)

    Rasmussen, T. C.; Haborak, K. G.; Young, M. H.


    We develop the theoretical and applied framework for using sinusoidal pumping tests to estimate aquifer properties for confined, leaky, and partially penetrating conditions. The framework 1) derives analytical solutions for three boundary conditions suitable for many practical applications, 2) validates the analytical solutions against a finite element model, 3) establishes a protocol for conducting sinusoidal pumping tests, and 4) estimates aquifer hydraulic parameters based on the analytical solutions. The analytical solutions to sinusoidal stimuli in radial coordinates are derived for boundary value problems that are analogous to the Theis (1935) confined aquifer solution, the Hantush and Jacob (1955) leaky aquifer solution, and the Hantush (1964) partially penetrated confined aquifer solution. The analytical solutions compare favorably to a finite-element solution of a simulated flow domain, except in the region immediately adjacent to the pumping well where the implicit assumption of zero borehole radius is violated. The procedure is demonstrated in one unconfined and two confined aquifer units near the General Separations Area at the Savannah River Site, a federal nuclear facility located in South Carolina. Aquifer hydraulic parameters estimated using this framework provide independent confirmation of parameters obtained from conventional aquifer tests. The sinusoidal approach also resulted in the elimination of investigation-derived wastes.

  3. Evaluating drywells for stormwater management and enhanced aquifer recharge (United States)

    Sasidharan, Salini; Bradford, Scott A.; Šimůnek, Jiří; DeJong, Bill; Kraemer, Stephen R.


    Drywells are increasingly used for stormwater management and enhanced aquifer recharge, but only limited research has quantitatively determined the performance of drywells. Numerical and field scale experiments were, therefore, conducted to improve our understanding and ability to characterize the drywell behavior. In particular, HYDRUS (2D/3D) was modified to simulate transient head boundary conditions for the complex geometry of the Maxwell Type IV drywell; i.e., a sediment chamber, an overflow pipe, and the variable geometry and storage of the drywell system with depth. Falling-head infiltration experiments were conducted on drywells located at the National Training Center in Fort Irwin, California (CA) and a commercial complex in Torrance, CA to determine in situ soil hydraulic properties (the saturated hydraulic conductivity, Ks, and the retention curve shape parameter, α) for an equivalent uniform soil profile by inverse parameter optimization. A good agreement between the observed and simulated water heights in wells was obtained for both sites as indicated by the coefficient of determination 0.95-0.99-%, unique parameter fits, and small standard errors. Fort Irwin and Torrance drywells had very distinctive soil hydraulic characteristics. The fitted value of Ks=1.01 × 10-3 m min-1 at the Torrance drywell was consistent with the sandy soil texture at this site and the default value for sand in the HYDRUS soil catalog. The drywell with this Ks= 1.01 × 10-3 m min-1 could easily infiltrate predicted surface runoff from a design rain event (∼51.3 m3) within 5760 min (4 d). In contrast, the fitted value of Ks=2.25 × 10-6 m min-1 at Fort Irwin was very low compared to the Torrance drywell and more than an order of magnitude smaller than the default value reported in the HYDRUS soil catalog for sandy clay loam at this site, likely due to clogging. These experiments and simulations provide useful information to characterize effective soil hydraulic properties

  4. Temporal naturalism (United States)

    Smolin, Lee


    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  5. Geochemistry of the Arbuckle-Simpson Aquifer (United States)

    Christenson, Scott; Hunt, Andrew G.; Parkhurst, David L.; Osborn, Noel I.


    The Arbuckle-Simpson aquifer in south-central Oklahoma provides water for public supply, farms, mining, wildlife conservation, recreation, and the scenic beauty of springs, streams, and waterfalls. A new understanding of the aquifer flow system was developed as part of the Arbuckle-Simpson Hydrology Study, done in 2003 through 2008 as a collaborative research project between the State of Oklahoma and the Federal government. The U.S. Geological Survey collected 36 water samples from 32 wells and springs in the Arbuckle-Simpson aquifer in 2004 through 2006 for geochemical analyses of major ions, trace elements, isotopes of oxygen and hydrogen, dissolved gases, and dating tracers. The geochemical analyses were used to characterize the water quality in the aquifer, to describe the origin and movement of ground water from recharge areas to discharge at wells and springs, and to determine the age of water in the aquifer.

  6. Economics of Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Robert G. Maliva


    Full Text Available Managed aquifer recharge (MAR technologies can provide a variety of water resources management benefits by increasing the volume of stored water and improving water quality through natural aquifer treatment processes. Implementation of MAR is often hampered by the absence of a clear economic case for the investment to construct and operate the systems. Economic feasibility can be evaluated using cost benefit analysis (CBA, with the challenge of monetizing benefits. The value of water stored or treated by MAR systems can be evaluated by direct and indirect measures of willingness to pay including market price, alternative cost, value marginal product, damage cost avoided, and contingent value methods. CBAs need to incorporate potential risks and uncertainties, such as failure to meet performance objectives. MAR projects involving high value uses, such as potable supply, tend to be economically feasible provided that local hydrogeologic conditions are favorable. They need to have low construction and operational costs for lesser value uses, such as some irrigation. Such systems should therefore be financed by project beneficiaries, but dichotomies may exist between beneficiaries and payers. Hence, MAR projects in developing countries may be economically viable, but external support is often required because of limited local financial resources.

  7. [Fish community structure and its seasonal change in subtidal sandy beach habitat off southern Gouqi Island]. (United States)

    Wang, Zhen-Hua; Wang, Kai; Zhao, Jing; Zhang, Shou-Yu


    To understand the characteristics of fish community structure in sandy beach habitats of island reef water areas, and to evaluate the potential capacity of these habitats in local fish stock maintenance, fishes were monthly collected with multi-mesh trammel nets in 2009 from the subtidal sandy beach habitat off southern Gouqi Island, taking the adjacent rocky reef habitat as the control. alpha and beta species diversity indices, index of relative importance (IRI), relative catch rate, and dominance curve for abundance and biomass (ABC curve) were adopted to compare the fish species composition, diversity, and community pattern between the two habitats, and multivariate statistical analyses such as non-metric multidimensional scaling (nMDS) and cluster were conducted to discuss the fish assemblage patterns. A total of 63 fish species belonging to 11 orders, 38 families, and 56 genera were collected, of which, 46 fish species were appeared in the two habitats. Due to the appearance of more warm water species in sandy bottom, the fishes in subtidal sandy beach habitat showed much higher richness, and the abundance catch rate (ACR) from May to July was higher than that in rocky reef habitat. In most rest months, the ACR in subtidal sandy beach habitat also showed the similar trend. However, the species richness and diversity in spring and summer were significantly lower in subtidal sandy beach habitat than in rocky reef habitat, because of the high species dominance and low evenness in the sandy beach habitat. Japanese tonguefish (Paraplagusia japonica) was the indicator species in the sandy beach habitat, and dominated in early spring, later summer, autumn, and winter when the fishing pressure was not strong. In sandy bottom, a unique community structure was formed and kept in dynamic, due to the nursery use of sandy beach by Japanese anchovy (Engraulis japonicus) from May to July, the gathering of gray mullet (Mugil cephalus) in most months for feeding, and the large

  8. Migration of cesium-137 through sandy soil layer effect of fine silt on migration

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko; Wadachi, Yoshiki


    The migration of 137 Cs through sandy soil layer was studied with consideration of the migration of fine silt by column method. It was found that a portion of fine silt migrated through the soil layer accompanying with 137 Cs. The mathematical migration model of 137 Cs involved the migration of fine silt through such soil layer was presented. This model gave a good accordance between calculated concentration distribution curve in sandy soil layer and effluent curve and observed those. So, this model seems to be advanced one for evaluating migration of 137 Cs in sandy soil layer with silt. (author)

  9. Quantifying aquifer properties and freshwater resource in coastal barriers: a hydrogeophysical approach applied at Sasihithlu (Karnataka state, India) (United States)

    Vouillamoz, J.-M.; Hoareau, J.; Grammare, M.; Caron, D.; Nandagiri, L.; Legchenko, A.


    Many human communities living in coastal areas in Africa and Asia rely on thin freshwater lenses for their domestic supply. Population growth together with change in rainfall patterns and sea level will probably impact these vulnerable groundwater resources. Spatial knowledge of the aquifer properties and creation of a groundwater model are required for achieving a sustainable management of the resource. This paper presents a ready-to-use methodology for estimating the key aquifer properties and the freshwater resource based on the joint use of two non-invasive geophysical tools together with common hydrological measurements. We applied the proposed methodology in an unconfined aquifer of a coastal sandy barrier in South-Western India. We jointly used magnetic resonance and transient electromagnetic soundings and we monitored rainfall, groundwater level and groundwater electrical conductivity. The combined interpretation of geophysical and hydrological results allowed estimating the aquifer properties and mapping the freshwater lens. Depending on the location and season, we estimate the freshwater reserve to range between 400 and 700 L m-2 of surface area (± 50%). We also estimate the recharge using time lapse geophysical measurements with hydrological monitoring. After a rainy event close to 100% of the rain is reaching the water table, but the net recharge at the end of the monsoon is less than 10% of the rain. Thus, we conclude that a change in rainfall patterns will probably not impact the groundwater resource since most of the rain water recharging the aquifer is flowing towards the sea and the river. However, a change in sea level will impact both the groundwater reserve and net recharge.

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

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


    The availability of reliable water supplies is a key factor limiting development in northern Australia. However, characterising groundwater resources in this remote part of Australia is challenging due to a lack of existing infrastructure and data. Here, direct push technology (DPT) was used to characterise shallow alluvial aquifers at two locations in the semiarid Flinders River catchment. DPT was used to evaluate the saturated thickness of the aquifer and estimate recharge rates by sampling for environmental tracers in groundwater (major ions, 2H, 18O, 3H and 14C). The alluvium at Fifteen Mile Reserve and Glendalough Station consisted of a mixture of permeable coarse sandy and gravely sediments and less permeable clays and silts. The alluvium was relatively thin (i.e. < 20 m) and, at the time of the investigation, was only partially saturated. Tritium (3H) concentrations in groundwater was ∼1 Tritium Unit (TU), corresponding to a mean residence time for groundwater of about 12 years. The lack of an evaporation signal for the 2H and 18O of groundwater suggests rapid localised recharge from overbank flood events as the primary recharge mechanism. Using the chloride mass balance technique (CMB) and lumped parameter models to interpret patterns in 3H in the aquifer, the mean annual recharge rate varied between 21 and 240 mm/yr. Whilst this recharge rate is relatively high for a semiarid climate, the alluvium is thin and heterogeneous hosting numerous alluvial aquifers with varied connectivity and limited storage capacity. Combining DPT and environmental tracers is a cost-effective strategy to characterise shallow groundwater resources in unconsolidated sedimentary aquifers in remote data sparse areas.

  11. Quantifying aquifer properties and freshwater resource in coastal barriers: a hydrogeophysical approach applied at Sasihithlu (Karnataka state, India

    Directory of Open Access Journals (Sweden)

    J.-M. Vouillamoz


    Full Text Available Many human communities living in coastal areas in Africa and Asia rely on thin freshwater lenses for their domestic supply. Population growth together with change in rainfall patterns and sea level will probably impact these vulnerable groundwater resources. Spatial knowledge of the aquifer properties and creation of a groundwater model are required for achieving a sustainable management of the resource. This paper presents a ready-to-use methodology for estimating the key aquifer properties and the freshwater resource based on the joint use of two non-invasive geophysical tools together with common hydrological measurements.

    We applied the proposed methodology in an unconfined aquifer of a coastal sandy barrier in South-Western India. We jointly used magnetic resonance and transient electromagnetic soundings and we monitored rainfall, groundwater level and groundwater electrical conductivity. The combined interpretation of geophysical and hydrological results allowed estimating the aquifer properties and mapping the freshwater lens. Depending on the location and season, we estimate the freshwater reserve to range between 400 and 700 L m−2 of surface area (± 50%. We also estimate the recharge using time lapse geophysical measurements with hydrological monitoring. After a rainy event close to 100% of the rain is reaching the water table, but the net recharge at the end of the monsoon is less than 10% of the rain. Thus, we conclude that a change in rainfall patterns will probably not impact the groundwater resource since most of the rain water recharging the aquifer is flowing towards the sea and the river. However, a change in sea level will impact both the groundwater reserve and net recharge.

  12. Early Dialysis and Adverse Outcomes After Hurricane Sandy. (United States)

    Lurie, Nicole; Finne, Kristen; Worrall, Chris; Jauregui, Maria; Thaweethai, Tanayott; Margolis, Gregg; Kelman, Jeffrey


    Hemodialysis patients have historically experienced diminished access to care and increased adverse outcomes after natural disasters. Although "early dialysis" in advance of a storm is promoted as a best practice, evidence for its effectiveness as a protective measure is lacking. Building on prior work, we examined the relationship between the receipt of dialysis ahead of schedule before the storm (also known as early dialysis) and adverse outcomes of patients with end-stage renal disease in the areas most affected by Hurricane Sandy. Retrospective cohort analysis, using claims data from the Centers for Medicare & Medicaid Services Datalink Project. Patients receiving long-term hemodialysis in New York City and the state of New Jersey, the areas most affected by Hurricane Sandy. Receipt of early dialysis compared to their usual treatment pattern in the week prior to the storm. Emergency department (ED) visits, hospitalizations, and 30-day mortality following the storm. Of 13,836 study patients, 8,256 (60%) received early dialysis. In unadjusted logistic regression models, patients who received early dialysis were found to have lower odds of ED visits (OR, 0.75; 95% CI, 0.63-0.89; P=0.001) and hospitalizations (OR, 0.77; 95% CI, 0.65-0.92; P=0.004) in the week of the storm and similar odds of 30-day mortality (OR, 0.80; 95% CI, 0.58-1.09; P=0.2). In adjusted multivariable logistic regression models, receipt of early dialysis was associated with lower odds of ED visits (OR, 0.80; 95% CI, 0.67-0.96; P=0.01) and hospitalizations (OR, 0.79; 95% CI, 0.66-0.94; P=0.01) in the week of the storm and 30-day mortality (OR, 0.72; 95% CI, 0.52-0.997; P=0.048). Inability to determine which patients were offered early dialysis and declined and whether important unmeasured patient characteristics are associated with receipt of early dialysis. Patients who received early dialysis had significantly lower odds of having an ED visit and hospitalization in the week of the storm and of

  13. Model-based analysis of δ34S signatures to trace sedimentary pyrite oxidation during managed aquifer recharge in a heterogeneous aquifer (United States)

    Seibert, Simone; Descourvieres, Carlos; Skrzypek, Grzegorz; Deng, Hailin; Prommer, Henning


    The oxidation of pyrite is often one of the main drivers affecting groundwater quality during managed aquifer recharge in deep aquifers. Data and techniques that allow detailed identification and quantification of pyrite oxidation are therefore crucial for assessing and predicting the adverse water quality changes that may be associated with this process. In this study, we explore the benefits of combining stable sulphur isotope analysis with reactive transport modelling to improve the identification and characterisation of pyrite oxidation during an aquifer storage and recovery experiment in a chemically and physically heterogeneous aquifer. We characterise the stable sulphur isotope signal (δ34S) in both the ambient groundwater and the injectant as well as its spatial distribution within the sedimentary sulphur species. The identified stable sulphur isotope signal for pyrite was found to vary between -32 and +34‰, while the signal of the injectant ranged between +9.06 and +14.45‰ during the injection phase of the experiment. Both isotope and hydrochemical data together suggest a substantial contribution of pyrite oxidation to the observed, temporally variable δ34S signals. The variability of the δ34S signal in pyrite and the injectant were both found to complicate the analysis of the stable isotope data. However, the incorporation of the data into a numerical modelling approach allowed to successfully employ the δ34S signatures as a valuable additional constraint for identifying and quantifying the contribution of pyrite oxidation to the redox transformations that occur in response to the injection of oxygenated water.

  14. Temporal contingency (United States)

    Gallistel, C.R.; Craig, Andrew R.; Shahan, Timothy A.


    Contingency, and more particularly temporal contingency, has often figured in thinking about the nature of learning. However, it has never been formally defined in such a way as to make it a measure that can be applied to most animal learning protocols. We use elementary information theory to define contingency in such a way as to make it a measurable property of almost any conditioning protocol. We discuss how making it a measurable construct enables the exploration of the role of different contingencies in the acquisition and performance of classically and operantly conditioned behavior. PMID:23994260

  15. Temporal contingency. (United States)

    Gallistel, C R; Craig, Andrew R; Shahan, Timothy A


    Contingency, and more particularly temporal contingency, has often figured in thinking about the nature of learning. However, it has never been formally defined in such a way as to make it a measure that can be applied to most animal learning protocols. We use elementary information theory to define contingency in such a way as to make it a measurable property of almost any conditioning protocol. We discuss how making it a measurable construct enables the exploration of the role of different contingencies in the acquisition and performance of classically and operantly conditioned behavior. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Content Analysis of Select YouTube Postings: Comparisons of Reactions to the Sandy Hook and Aurora Shootings and Hurricane Sandy. (United States)

    Miller, Eric D


    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.

  17. Assessment of land degradation using time series trend analysis of vegetation indictors in Otindag Sandy land

    International Nuclear Information System (INIS)

    Wang, H Y; Li, Z Y; Gao, Z H; Wu, J J; Sun, B; Li, C L


    Land condition assessment is a basic prerequisite for finding the degradation of a territory, which might lead to desertification under climatic and human pressures. The temporal change in vegetation productivity is a key indicator of land degradation. In this paper, taking the Otindag Sandy Land as a case, the mean normalized difference vegetation index (NDVI a ), net primary production (NPP) and vegetation rain use efficiency (RUE) dynamic trends during 2001–2010 were analysed. The Mann-Kendall test and the Correlation Analysis method were used and their sensitivities to land degradation were evaluated. The results showed that the three vegetation indicators (NDVI a , NPP and RUE) showed a downward trend with the two methods in the past 10 years and the land was degraded. For the analysis of the three vegetation indicators (NDVI a , NPP and RUE), it indicated a decreasing trend in 62.57%, 74.16% and 88.56% of the study area according to the Mann-Kendall test and in 57.85%, 68.38% and 85.29% according to the correlation analysis method. However, the change trends were not significant, the significant trends at the 95% confidence level only accounted for a small proportion. Analysis of NDVI a , NPP and RUE series showed a significant decreasing trend in 9.21%, 4.81% and 6.51% with the Mann-Kendall test. The NPP change trends showed obvious positive link with the precipitation in the study area. While the effect of the inter-annual variation of the precipitation for RUE was small, the vegetation RUE can provide valuable insights into the status of land condition and had best sensitivity to land degradation

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

    Directory of Open Access Journals (Sweden)

    Djalma Eugênio Schmitt


    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.

  19. Spatial variability of macrobenthic zonation on exposed sandy beaches (United States)

    Veiga, Puri; Rubal, Marcos; Cacabelos, Eva; Maldonado, Cristina; Sousa-Pinto, Isabel


    We analysed the consistence of vertical patterns of distribution (i.e. zonation) for macrofauna at different spatial scales on four intermediate exposed beaches in the North of Portugal. We tested the hypothesis that biological zonation on exposed sandy beaches would vary at the studied spatial scales. For this aim, abundance, diversity and structure of macrobenthic assemblages were examined at the scales of transect and beach. Moreover, the main environmental factors that could potentially drive zonation patterns were investigated. Univariate and multivariate analyses revealed that the number of biological zones ranged from two to three depending on the beach and from indistinct zonation to three zones at the scale of transect. Therefore, results support our working hypothesis because zonation patterns were not consistent at the studied spatial scales. The median particle size, sorting coefficient and water content were significantly correlated with zonation patterns of macrobenthic assemblages. However, a high degree of correlation was not reached when the total structure of the assemblage was considered.

  20. Effects of leachate on geotechnical characteristics of sandy clay soil (United States)

    Harun, N. S.; Ali, Z. Rahman; Rahim, A. S.; Lihan, T.; Idris, R. M. W.


    Leachate is a hazardous liquid that poses negative impacts if leaks out into environments such as soil and ground water systems. The impact of leachate on the downgraded quality in terms of chemical characteristic is more concern rather than the physical or mechanical aspect. The effect of leachate on mechanical behaviour of contaminated soil is not well established and should be investigated. This paper presents the preliminary results of the effects of leachate on the Atterberg limit, compaction and shear strength of leachate-contaminated soil. The contaminated soil samples were prepared by mixing the leachate at ratiosbetween 0% and 20% leachate contents with soil samples. Base soil used was residual soil originated from granitic rock and classified as sandy clay soil (CS). Its specific gravity ranged between 2.5 and 2.64 with clay minerals of kaolinite, muscovite and quartz. The field strength of the studied soil ranged between 156 and 207 kN/m2. The effects of leachate on the Atterberg limit clearly indicated by the decrease in liquid and plastic limit values with the increase in the leachate content. Compaction tests on leachate-contaminated soil caused the dropped in maximum dry density, ρdry and increased in optimum moisture content, wopt when the amount of leachate was increased between 0% and 20%. The results suggested that leachate contamination capable to modify some geotechnical properties of the studied residual soils.

  1. Exploring the social dimension of sandy beaches through predictive modelling. (United States)

    Domínguez-Tejo, Elianny; Metternicht, Graciela; Johnston, Emma L; Hedge, Luke


    Sandy beaches are unique ecosystems increasingly exposed to human-induced pressures. Consistent with emerging frameworks promoting this holistic approach towards beach management, is the need to improve the integration of social data into management practices. This paper aims to increase understanding of links between demographics and community values and preferred beach activities, as key components of the social dimension of the beach environment. A mixed method approach was adopted to elucidate users' opinions on beach preferences and community values through a survey carried out in Manly Local Government Area in Sydney Harbour, Australia. A proposed conceptual model was used to frame demographic models (using age, education, employment, household income and residence status) as predictors of these two community responses. All possible regression-model combinations were compared using Akaike's information criterion. Best models were then used to calculate quantitative likelihoods of the responses, presented as heat maps. Findings concur with international research indicating the relevance of social and restful activities as important social links between the community and the beach environment. Participant's age was a significant variable in the four predictive models. The use of predictive models informed by demographics could potentially increase our understanding of interactions between the social and ecological systems of the beach environment, as a prelude to integrated beach management approaches. The research represents a practical demonstration of how demographic predictive models could support proactive approaches to beach management. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Field sampling of residual aviation gasoline in sandy soil

    International Nuclear Information System (INIS)

    Ostendorf, D.W.; Hinlein, E.S.; Yuefeng, Xie; Leach, L.E.


    Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions

  3. Measurement of indoor and outdoor radon concentrations during Superstorm Sandy. (United States)

    Kotrappa, Payasada; Paul, Prateek; Stieff, Alex; Stieff, Frederick


    Superstorm Sandy affected much of the US East Coast extending over 1800 km. It passed over the test location in the State of Maryland on 29 October 2012. Being 350 km away from the regions of highest intensity the storm was of lower intensity at the test location. Continuous radon monitors and passive radon monitors were used for the measurement. The test location was the basement of a single family home representing the indoor concentration. A partially opened garage of the same test home represented the outdoor radon concentration. In 24 h, the atmospheric pressure dropped from 990 to 960 mbar and the indoor radon concentration increased from 70 to 1500 Bq m(-3) and returned to the normal of 70 Bq m(-3) at the end of the storm. Throughout the storm, the outdoor radon concentration was not significantly affected. Probable reasons for such surprisingly large changes are discussed. However, the outdoor temperature dropped from 13°C to 7°C during the radon peak.

  4. Thermomechanical Behavior of Energy Pile Embedded in Sandy Soil

    Directory of Open Access Journals (Sweden)

    Xu Huang


    Full Text Available The traditional energy pile (solid energy pile has been implemented for decades. However, the design of different kinds of energy piles is still not well understood. In this study, a series of model tests were performed on an aluminum pipe energy pile (PEP in dry sandy soil to investigate the thermal effects on the mechanical behaviors of pipe energy pile. The thermal responses of the PEP were also analyzed. Steady temperatures of the PEP under different working conditions were also compared with that of the solid energy pile. Different loading tests were carried out on four pipe energy piles under three different temperatures of 5, 35, and 50°C, respectively. The bearing capacity change can be interpreted through the load-displacement curves. Experiment results were also compared with the solid energy pile to evaluate bearing capacities of the PEP and the solid energy pile under different temperature conditions. The mobilized shaft resistance was also calculated and compared with the solid energy pile data and the results show that the PEP has a similar load transfer mechanism with the solid energy pile. It could also be found that, for PEPs under working load, plastic displacement would appear after a whole heating cycle.

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

    CERN Document Server

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


    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 ...

  6. Field Investigation of Natural Attenuation of a Petroleum Hydrocarbon Contaminated Aquifer, Gyeonggi Province, Korea (United States)

    Yang, J.; Lee, K.; Bae, G.


    In remediation of a petroleum hydrocarbon contaminated aquifer, natural attenuation may be significant as a remedial alternative. Therefore, natural attenuation should be investigated in the field in order to effectively design and evaluate the remediation strategy at the contaminated site. This study focused on evaluating the natural attenuation for benzene, toluene, ethylbenzene, and xylene (BTEX) at a contaminated site in South Korea. At the study site, the aquifer is composed of a high permeable gravel layer and relatively low permeable sandy-silt layers. Groundwater level vertically fluctuated between 1m and 2m throughout the year (April, 2003~June, 2004) and showed direct response to rainfall events. Chemical analyses of sampled groundwater were performed to investigate the concentrations of various chemical species which are associated with the natural attenuation processes. To evaluate the degree of the biodegradation, the expressed biodegradation capacity (EBC) analysis was done using aerobic respiration, nitrate reduction, manganese reduction, ferric iron reduction, and sulfate reduction as an indicator. High EBC value of sulfate indicate that anaerobic biodegradation by sulfate reduction was a dominant process of mineralization of BTEX at this site. The EBC values decrease sensitively when heavy rainfall occurs due to the dilution and inflow of electron acceptors through a gravel layer. The first-order biodegradation rates of BTEX were estimated by means of the Buscheck and Alcantar method (1995). Results show that the natural attenuation rate of benzene was the highest among the BTEX.

  7. 78 FR 33467 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy... (United States)


    ... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy: Response, Recovery & Resiliency; Correction... allocation of $3.7 billion under the Public Transportation Emergency Relief Program to the four FTA...

  8. 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey) (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....

  9. Amelioration of sandy soils in drought stricken areas through use of ...

    African Journals Online (AJOL)


    improving N, P, Ca and Mg content in sandy soils, and consequently support crop growth and yield. ... stress, soil moisture conservation, soil fertility management ... water many times its own weight. ... improves the productivity of degraded,.

  10. 2012 USGS EAARL-B Coastal Topography: Post-Sandy, First Surface (NJ) (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...

  11. Expanded uncertainty estimation methodology in determining the sandy soils filtration coefficient (United States)

    Rusanova, A. D.; Malaja, L. D.; Ivanov, R. N.; Gruzin, A. V.; Shalaj, V. V.


    The combined standard uncertainty estimation methodology in determining the sandy soils filtration coefficient has been developed. The laboratory researches were carried out which resulted in filtration coefficient determination and combined uncertainty estimation obtaining.

  12. Will the future atmospheric circulation favor the landfall of Sandy-like superstorms? (Invited) (United States)

    Barnes, E. A.; Polvani, L. M.; Sobel, A. H.


    Superstorm Sandy ravaged the Eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here, we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the CMIP5 multi-model ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy's unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

  13. 2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area (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...

  14. 2012-2013 Post-Hurricane Sandy EAARL-B Submerged Topography - Barnegat Bay, New Jersey (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...

  15. Characterization of a managed aquifer recharge system using multiple tracers. (United States)

    Moeck, Christian; Radny, Dirk; Popp, Andrea; Brennwald, Matthias; Stoll, Sebastian; Auckenthaler, Adrian; Berg, Michael; Schirmer, Mario


    Knowledge about the residence times of artificially infiltrated water into an aquifer and the resulting flow paths is essential to developing groundwater-management schemes. To obtain this knowledge, a variety of tracers can be used to study residence times and gain information about subsurface processes. Although a variety of tracers exists, their interpretation can differ considerably due to subsurface heterogeneity, underlying assumptions, and sampling and analysis limitations. The current study systematically assesses information gained from seven different tracers during a pumping experiment at a site where drinking water is extracted from an aquifer close to contaminated areas and where groundwater is artificially recharged by infiltrating surface water. We demonstrate that the groundwater residence times estimated using dye and heat tracers are comparable when the thermal retardation for the heat tracer is considered. Furthermore, major ions, acesulfame, and stable isotopes (δ 2 H and δ 18 O) show that mixing of infiltrated water and groundwater coming from the regional flow path occurred and a vertical stratification of the flow system exist. Based on the concentration patterns of dissolved gases (He, Ar, Kr, N 2 , and O 2 ) and chlorinated solvents (e.g., tetrachloroethene), three temporal phases are observed in the ratio between infiltrated water and regional groundwater during the pumping experiment. Variability in this ratio is significantly related to changes in the pumping and infiltration rates. During constant pumping rates, more infiltrated water was extracted, which led to a higher dilution of the regional groundwater. An infiltration interruption caused however, the ratio to change and more regional groundwater is extracted, which led to an increase in all concentrations. The obtained results are discussed for each tracer considered and its strengths and limitations are illustrated. Overall, it is demonstrated that aquifer heterogeneity and

  16. Hydrology of the Claiborne aquifer and interconnection with the Upper Floridan aquifer in southwest Georgia (United States)

    Gordon, Debbie W.; Gonthier, Gerard


    The U.S. Geological Survey conducted a study, in cooperation with the Georgia Environmental Protection Division, to define the hydrologic properties of the Claiborne aquifer and evaluate its connection with the Upper Floridan aquifer in southwest Georgia. The effort involved collecting and compiling hydrologic data from the aquifer in subarea 4 of southwestern Georgia. Data collected for this study include borehole geophysical logs in 7 wells, and two 72-hour aquifer tests to determine aquifer properties.The top of the Claiborne aquifer extends from an altitude of about 200 feet above the North American Vertical Datum of 1988 (NAVD 88) in Terrell County to 402 feet below NAVD 88 in Decatur County, Georgia. The base of the aquifer extends from an altitude of about 60 feet above NAVD 88 in eastern Sumter County to about 750 feet below NAVD 88 in Decatur County. Aquifer thickness ranges from about 70 feet in eastern Early County to 400 feet in Decatur County.The transmissivity of the Claiborne aquifer, determined from two 72-hour aquifer tests, was estimated to be 1,500 and 700 feet squared per day in Mitchell and Early Counties, respectively. The storage coefficient was estimated to be 0.0006 and 0.0004 for the same sites, respectively. Aquifer test data from Mitchell County indicate a small amount of leakage occurred during the test. Groundwater-flow models suggest that the source of the leakage was the underlying Clayton aquifer, which produced about 2.5 feet of drawdown in response to pumping in the Claiborne aquifer. The vertical hydraulic conductivity of the confining unit between the Claiborne and Clayton aquifers was simulated to be about 0.02 foot per day.Results from the 72-hour aquifer tests run for this study indicated no interconnection between the Claiborne and overlying Upper Floridan aquifers at the two test sites. Additional data are needed to monitor the effects that increased withdrawals from the Claiborne aquifer may have on future water resources.

  17. Substrate interactions of benzene, toluene, and para-xylene during microbial degradation by pure cultures and mixed culture aquifer slurries

    International Nuclear Information System (INIS)

    Alvarez, P.J.J.; Vogel, T.M.


    Release of petroleum hydrocarbons in the environment is a widespread occurrence. One particular concern is the contamination of drinking water sources by the toxic, water-soluble, and mobile petroleum components benzene, toluene, and xylene (BTX). Benzene, toluene, and p-xylene (BTX) were degraded by indigenous mixed cultures in sandy aquifer material and by two pure cultures isolated from the same site. Although BTX compounds have a similar chemical structure, the fate of individual BTX compounds differed when the compounds were fed to each pure culture and mixed culture aquifer slurries. The identification of substrate interactions aided the understanding of this behavior. Beneficial substrate interactions included enhanced degradation of benzene-dependent degradation of toluene and p-xylene by Arthrobacter sp. strain HCB. Detrimental substrate interactions included retardation in benzene and toluene degradation by the presence of p-xylene in both aquifer slurries and Pseudomonas incubations. The catabolic diversity of microbes in the environment precludes generalizations about the capacity of individual BTX compounds to enhance or inhibit the degradation of other BTX compounds

  18. Characterization of the Spatial and Temporal Variations of Submarine Groundwater Discharge Using Electrical Resistivity and Seepage Measurements (United States)

    Durand, Josephine Miryam Kalyanie

    Submarine groundwater discharge (SGD) encompasses all fluids crossing the sediment/ocean interface, regardless of their origin, composition or driving forces. SGD provides a pathway for terrestrial contaminants that can significantly impact coastal ecosystems. Overexploitation of groundwater resources can decrease SGD which favors seawater intrusion at depth. Understanding SGD is therefore crucial for water quality and resource management. Quantifying SGD is challenging due to its diffuse and heterogeneous nature, in addition to significant spatio-temporal variations at multiple scales. In this thesis, an integrated approach combining electrical resistivity (ER) surveys, conductivity and temperature point measurements, seepage rates using manual and ultrasonic seepage meters, and pore fluid salinities was used to characterize SGD spatio-temporal variations and their implications for contaminant transport at several locations on Long Island, NY. The influence of surficial sediments on SGD distribution was investigated in Stony Brook Harbor. A low-permeability mud layer, actively depositing in the harbor, limits SGD at the shoreline, prevents mixing with seawater and channels a significant volume of freshwater offshore. SGD measured at locations without mud is high and indicates significant mixing between porewater and seawater. A 2D steady-state density-difference numerical model of the harbor was developed using SEAWAT and was validated by our field observations. Temporal variations of SGD due to semi-diurnal tidal forcing were studied in West Neck Bay, Shelter Island, using a 12-hr time-lapse ER survey together with continuous salinity and seepage measurements in the intertidal zone. The observed dynamic patterns of groundwater flux and salinity distribution disagree with published standard transient state numerical models, suggesting the need for developing more specific models of non-homogeneous anisotropic aquifers. SGD distribution and composition were

  19. Migration characteristics of cobalt-60 through sandy soil in high pH solution

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko


    Migration characteristics of 60 Co through sandy soil in high pH solution has been investigated by both column and batch techniques. The association of 60 Co with the sandy soil and its components were studied by sequential extraction techniques. The concentration profile of 60 Co in the sandy soil column was composed of two exponential curves showing that 60 Co would consist of immobile and mobile fractions. The immobile 60 Co was retained by the sandy soil and was distributed near the top. Though the mobile 60 Co was little sorbed by soil and migrated through the soil column, maximum concentration of 60 Co in the effluents decreased slightly with increasing path length of the soil column. The sequential extraction of 60 Co from the sandy soil and from its components showed that 60 Co was sorbed by both manganese oxide and clay minerals. And manganese oxide is one of the responsible soil components for the observed decrease in the maximum concentration of 60 Co in the effluents. Although the content of manganese oxide in the sandy soil was 0.13%, manganese oxide is the important component to prevent from the migration of 60 Co in the high pH solution. (author)


    Directory of Open Access Journals (Sweden)

    Patrick S. Michael


    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

  1. Rates of Hospitalization for Dehydration Following Hurricane Sandy in New Jersey. (United States)

    Swerdel, Joel N; Rhoads, George G; Cosgrove, Nora M; Kostis, John B


    Hurricane Sandy, one of the most destructive natural disasters in New Jersey history, made landfall on October 29, 2012. Prolonged loss of electrical power and extensive infrastructure damage restricted access for many to food and water. We examined the rate of dehydration in New Jersey residents after Hurricane Sandy. We obtained data from 2008 to 2012 from the Myocardial Infarction Data Acquisition System (MIDAS), a repository of in-patient records from nonfederal New Jersey hospitals (N=517,355). Patients with dehydration had ICD-9-CM discharge diagnosis codes for dehydration, volume depletion, and/or hypovolemia. We used log-linear modeling to estimate the change in in-patient hospitalizations for dehydration comparing 2 weeks after Sandy with the same period in the previous 4 years (2008-2011). In-patient hospitalizations for dehydration were 66% higher after Sandy than in 2008-2011 (rate ratio [RR]: 1.66; 95% confidence interval [CI]: 1.50, 1.84). Hospitalizations for dehydration in patients over 65 years of age increased by nearly 80% after Sandy compared with 2008-2011 (RR: 1.79; 95% CI: 1.58, 2.02). Sandy was associated with a marked increase in hospitalizations for dehydration. Reducing the rate of dehydration following extreme weather events is an important public health concern that needs to be addressed, especially in those over 65 years of age.

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


    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.

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

    Directory of Open Access Journals (Sweden)

    M. Kunz


    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.

  4. Effects of Pisha sandstone content on solute transport in a sandy soil. (United States)

    Zhen, Qing; Zheng, Jiyong; He, Honghua; Han, Fengpeng; Zhang, Xingchang


    In sandy soil, water, nutrients and even pollutants are easily leaching to deeper layers. The objective of this study was to assess the effects of Pisha sandstone on soil solute transport in a sandy soil. The miscible displacement technique was used to obtain breakthrough curves (BTCs) of Br(-) as an inert non-adsorbed tracer and Na(+) as an adsorbed tracer. The incorporation of Pisha sandstone into sandy soil was able to prevent the early breakthrough of both tracers by decreasing the saturated hydraulic conductivity compared to the controlled sandy soil column, and the impeding effects increased with Pisha sandstone content. The BTCs of Br(-) were accurately described by both the convection-dispersion equation (CDE) and the two-region model (T-R), and the T-R model fitted the experimental data slightly better than the CDE. The two-site nonequilibrium model (T-S) accurately fit the Na(+) transport data. Pisha sandstone impeded the breakthrough of Na(+) not only by decreasing the saturated hydraulic conductivity but also by increasing the adsorption capacity of the soil. The measured CEC values of Pisha sandstone were up to 11 times larger than those of the sandy soil. The retardation factors (R) determined by the T-S model increased with increasing Pisha sandstone content, and the partition coefficient (K(d)) showed a similar trend to R. According to the results of this study, Pisha sandstone can successfully impede solute transport in a sandy soil column. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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


    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.

  6. Development and Modelling of a High-Resolution Aquifer Analog in the Guarani Aquifer (Brazil)


    Höyng, Dominik


    A comprehensive and detailed knowledge about the spatial distribution of physical and chemical properties in heterogeneous porous aquifers plays a decisive role for a realistic representation of governing parameters in mathematical models. Models allow the simulation, prediction and reproduction of subsurface flow and transport characteristics. This work explains the identification, characterization and effects of small-scale aquifer heterogeneities in the Guarani Aquifer System (GAS) in S...

  7. Comparison of aquifer characteristics derived from local and regional aquifer tests. (United States)

    Randolph, R.B.; Krause, R.E.; Maslia, M.L.


    A comparison of the aquifer parameter values obtained through the analysis of a local and a regional aquifer test involving the same area in southeast Georgia is made in order to evaluate the validity of extrapolating local aquifer-test results for use in large-scale flow simulations. Time-drawdown and time-recovery data were analyzed by using both graphical and least-squares fitting of the data to the Theis curve. Additionally, directional transmissivity, transmissivity tensor, and angle of anisotropy were computed for both tests. -from Authors Georgia drawdown transmissivity regional aquifer tests

  8. Trends and transformation of nutrients and pesticides in a Coastal Plain aquifer system, United States (United States)

    Denver, J.M.; Tesoriero, A.J.; Barbaro, J.R.


    Four local-scale sites in areas with similar corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] agriculture were studied to determine the effects of different hydrogeologic settings of the Northern Atlantic Coastal Plain (NACP) on the transport of nutrients and pesticides in groundwater. Settings ranged from predominantly well-drained soils overlying thick, sandy surficial aquifers to predominantly poorly drained soils with complex aquifer stratigraphy and high organic matter content. Apparent age of groundwater, dissolved gases, N isotopes, major ions, selected pesticides and degradates, and geochemical environments in groundwater were studied. Agricultural chemicals were the source of most dissolved ions in groundwater. Specific conductance was strongly correlated with reconstructed nitrate (the sum of N in nitrate and N gas) (R2 = 0.81, p < 0.0001), and is indicative of the relative degree of agricultural effects on groundwater. Trends in nitrate were primarily related to changes in manure and fertilizer use at the well-drained sites where aquifer conditions were consistently oxic. Nitrate was present in young groundwater but completely removed over time through denitrification at the poorly drained sites where there were variations in chemical input and in geochemical environment. Median concentrations of atrazine (6-chloro-N-ethyl-N'-(1- methylethyl)-1,3,5-triazine-2,4-diamine), metolachlor (2-chloro-N-(2-ethyl-6- methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide), and some of their common degradates were higher at well-drained sites than at poorly drained sites, with concentrations of degradates generally higher than those of the parent compounds at all sites. An increase in the percentage of deethylatrazine to total atrazine over time at one well-drained site may be related to changes in manure application. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  9. Study of aquifer's characteristic at BPLP-BATAN, Cipanas, West Java

    International Nuclear Information System (INIS)

    I Gde Sukadana; Adi Gunawan Muhammad


    Farms Observational Land Agricultural (BPLP) BATAN lies at Palasari's Village, Cipanas's district, Cianjur's regency, West Java. The currently used water resources, come from shallow well that groundwater's quality adverse, brownish rust colored, so indecent being utilized as source of fresh water. Drilling activity of groundwater exploration is objected in order to obtain aquifer's characteristics which cover lithology, porosity of lithology, ground water condition that interpreted from well cutting, bores-hole geophysical data, pumping test data and water quality on the aquifer. These Regions constitute geologically volcanic rock, varied of volcanic breccia with grain size of sand to boulder. Potential aquifers at these regions are conglomeratic sandstone, breccias, and sandstone. The result of drilling activity shows that its lithology are yield of soil (depth 0-6 m), breccia (36-38 m), middle-rough sandstone (depth 38-40 m), breccia (40-52 m), sandy breccia (depth 52-97 m) and inter spaced tuff with middle-rough sandstone (depth 97-125 m). As a result, therefore, the well has been constructed with straight PVC pipe 6'', on depth of 0-40 m made by grouting cements, screen is assembled on depth of 60-82 m and 90-110 m. Result of pumping test that well's with maximum debit 17,25 L/sec, and optimum debit 13,2 L/sec. Static water level on 11 m depth. Current assembled pump is 5 L/sec on the 86 m depth. Result of groundwater quality test in laboratory shows that the water has good quality with fresh water quality standard, which mean that the water is suitable to be consumed. (author)

  10. Mapping groundwater level and aquifer storage variations from InSAR measurements in the Madrid aquifer, Central Spain (United States)

    Béjar-Pizarro, Marta; Ezquerro, Pablo; Herrera, Gerardo; Tomás, Roberto; Guardiola-Albert, Carolina; Ruiz Hernández, José M.; Fernández Merodo, José A.; Marchamalo, Miguel; Martínez, Rubén


    Groundwater resources are under stress in many regions of the world and the future water supply for many populations, particularly in the driest places on Earth, is threatened. Future climatic conditions and population growth are expected to intensify the problem. Understanding the factors that control groundwater storage variation is crucial to mitigate its adverse consequences. In this work, we apply satellite-based measurements of ground deformation over the Tertiary detritic aquifer of Madrid (TDAM), Central Spain, to infer the spatio-temporal evolution of water levels and estimate groundwater storage variations. Specifically, we use Persistent Scatterer Interferometry (PSI) data during the period 1992-2010 and piezometric time series on 19 well sites covering the period 1997-2010 to build groundwater level maps and quantify groundwater storage variations. Our results reveal that groundwater storage loss occurred in two different periods, 1992-1999 and 2005-2010 and was mainly concentrated in a region of ∼200 km2. The presence of more compressible materials in that region combined with a long continuous water extraction can explain this volumetric deficit. This study illustrates how the combination of PSI and piezometric data can be used to detect small aquifers affected by groundwater storage loss helping to improve their sustainable management.

  11. Steam Injection For Soil And Aquifer Remediation (United States)

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by...

  12. Hydrogeologic characterization of devonian aquifers in Uruguay

    International Nuclear Information System (INIS)

    Massa, E.


    This article carried out the assistance research project implementation in devonian sedimentary units as a potentials aquifers and their best use to school supplying and rural population in central area of Uruguay.

  13. Aquifer parameter identification and interpretation with different ...

    African Journals Online (AJOL)

    unfortunately, field data deviations from the model type curves are not considered in ... Such an extensive Study can only he done when there is a set of aquifer test data with main and .... 1990; 1995) methods are employed for qualitative.

  14. Water management in sandy soil using neutron scattering method

    International Nuclear Information System (INIS)

    Mohamed, K.M.


    This study was carried out during 2008/2009 at the Experimental Field of Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Inshas in a newly reclaimed sandy soil. The aims of this work are,- determine soil moisture tension within the active root zone and - detecting the behavior of soil moisture within the active root zoon by defines the total hydraulic potential within the soil profile to predict both of actual evapotranspiration and rate of moisture depletion This work also is aimed to study soil water distribution under drip irrigation system.- reducing water deep percolation under the active root depth.This study included two factors, the first one is the irrigation intervals, and the second one is the application rate of organic manure. Irrigation intervals were 5, 10 and 15 days, besides three application rates of organic manure (0 m 3 /fed, 20 m 3 /fed. and 30 m 3 /fed.) in -three replicates under drip irrigation system, Onion was used as an indicator plant. Obtained data show, generally, that neutron scattering technique and soil moisture retention curve model helps more to study the water behavior in the soil profile.Application of organic manure and irrigation to field capacity is a good way to minimize evapotranspiration and deep percolation, which was zero mm/day in the treated treatments.The best irrigation interval for onion plant, in the studied soil, was 5 days with 30m 3 /fad. an application rate of organic manure.Parameter α of van Genuchent's 1980 model was affected by the additions of organic manure, which was decreased by addition of organic manure decreased it. Data also showed that n parameter was decreased by addition of organic manure Using surfer program is a good tool to describe the water distribution in two directions (vertical and horizontal) through soil profile.

  15. Modelling wind forced bedforms on a sandy beach

    NARCIS (Netherlands)

    de Vries, S.; Van Thiel de Vries, J.; Ruessink, B.G.


    This paper aims to conceptually simulate observed spatial and temporal variability in aeolian sediment transport rates, erosion and deposition on a beach. Traditional strategies of modeling aeolian sediment transport rates do not account for supply limitations that are common on natural beaches. A

  16. Using nitrate to quantify quick flow in a karst aquifer (United States)

    Mahler, B.J.; Garner, B.D.


    In karst aquifers, contaminated recharge can degrade spring water quality, but quantifying the rapid recharge (quick flow) component of spring flow is challenging because of its temporal variability. Here, we investigate the use of nitrate in a two-endmember mixing model to quantify quick flow in Barton Springs, Austin, Texas. Historical nitrate data from recharging creeks and Barton Springs were evaluated to determine a representative nitrate concentration for the aquifer water endmember (1.5 mg/L) and the quick flow endmember (0.17 mg/L for nonstormflow conditions and 0.25 mg/L for stormflow conditions). Under nonstormflow conditions for 1990 to 2005, model results indicated that quick flow contributed from 0% to 55% of spring flow. The nitrate-based two-endmember model was applied to the response of Barton Springs to a storm and results compared to those produced using the same model with ??18O and specific conductance (SC) as tracers. Additionally, the mixing model was modified to allow endmember quick flow values to vary over time. Of the three tracers, nitrate appears to be the most advantageous because it is conservative and because the difference between the concentrations in the two endmembers is large relative to their variance. The ??18O- based model was very sensitive to variability within the quick flow endmember, and SC was not conservative over the timescale of the storm response. We conclude that a nitrate-based two-endmember mixing model might provide a useful approach for quantifying the temporally variable quick flow component of spring flow in some karst systems. ?? 2008 National Ground Water Association.

  17. A General Solution for Groundwater Flow in Estuarine Leaky Aquifer System with Considering Aquifer Anisotropy (United States)

    Chen, Po-Chia; Chuang, Mo-Hsiung; Tan, Yih-Chi


    In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. Since the 1950s, numerous studies focused on the effect of tidal fluctuation on the groundwater flow in the coastal area. Many studies concentrated on the developments of one-dimensional (1D) and two-dimensional (2D) analytical solutions describing the tide-induced head fluctuations. For example, Jacob (1950) derived an analytical solution of 1D groundwater flow in a confined aquifer with a boundary condition subject to sinusoidal oscillation. Jiao and Tang (1999) derived a 1D analytical solution of a leaky confined aquifer by considered a constant groundwater head in the overlying unconfined aquifer. Jeng et al. (2002) studied the tidal propagation in a coupled unconfined and confined costal aquifer system. Sun (1997) presented a 2D solution for groundwater response to tidal loading in an estuary. Tang and Jiao (2001) derived a 2D analytical solution in a leaky confined aquifer system near open tidal water. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The predicted head fluctuations from this solution will compare with the simulation results from the MODFLOW program. In addition, the solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and

  18. Temporal Glare

    DEFF Research Database (Denmark)

    Ritschel, Tobias; Ihrke, Matthias; Frisvad, Jeppe Revall


    Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contra...... to initially static HDR images. By conducting psychophysical studies, we validate that our method improves perceived brightness and that dynamic glare-renderings are often perceived as more attractive depending on the chosen scene.......Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contrast....... Even though most, if not all, subjects report perceiving glare as a bright pattern that fluctuates in time, up to now it has only been modeled as a static phenomenon. We argue that the temporal properties of glare are a strong means to increase perceived brightness and to produce realistic...

  19. Insights on surface-water/groundwater exchange in the upper Floridan aquifer, north-central Florida (USA), from streamflow data and numerical modeling (United States)

    Sutton, James E.; Screaton, Elizabeth J.; Martin, Jonathan B.


    Surface-water/groundwater exchange impacts water quality and budgets. In karst aquifers, these exchanges also play an important role in dissolution. Five years of river discharge data were analyzed and a transient groundwater flow model was developed to evaluate large-scale temporal and spatial variations of exchange between an 80-km stretch of the Suwannee River in north-central Florida (USA) and the karstic upper Floridan aquifer. The one-layer transient groundwater flow model was calibrated using groundwater levels from 59 monitoring wells, and fluxes were compared to the exchange calculated from discharge data. Both the numerical modeling and the discharge analysis suggest that the Suwannee River loses water under both low- and high-stage conditions. River losses appear greatest at the inside of a large meander, and the former river water may continue across the meander within the aquifer rather than return to the river. In addition, the numerical model calibration reveals that aquifer transmissivity is elevated within this large meander, which is consistent with enhanced dissolution due to river losses. The results show the importance of temporal and spatial variations in head gradients to exchange between streams and karst aquifers and dissolution of the aquifers.

  20. Guarani aquifer hydrogeological synthesis of the Guarani aquifer system. Edicion bilingue

    International Nuclear Information System (INIS)


    This work represents the synthesis of current knowledge of the Guarani Aquifer System, based on technical products made by different companies and consultants who participated in the framework of the Project for Environmental Protection and Sustainable Development of the Guarani Aquifer.

  1. Aquifer response to earth tides

    International Nuclear Information System (INIS)

    Kanehiro, B.Y.; Narasimhan, T.N.


    The relation presented in the first part of this paper are applicable to packed-off wells and other situations where appreciable flow to the well does not exist. Comparisons of aquifer properties determined from the response to earth tides and from the more standard pumping tests for the two California fields are reasonably good. The case of an open well makes the problem more complicated, since there may be an appreciable amount of flow to the well. This flow to the well is seen as either a phase lag or as a difference in the ratio of the well signal to the tide for the semidiurnal and diurnal components of the tide. The latter is probably the better and more accurate indicator of flow to the well. Analyses of such situations, however, become involved and are probably best done as case-by-case studies. The numerical solutions show that treating the inverse problem through numerical modeling is at least feasible for any individual situation. It may be possible to simplify the inverse problem through the generation of type curves, but general type curves that are applicable to diverse situations are not likely to be practical. 7 figures

  2. Aquifer Storage Recovery (ASR) of chlorinated municipal drinking water in a confined aquifer (United States)

    Izbicki, John A.; Petersen, Christen E.; Glotzbach, Kenneth J.; Metzger, Loren F.; Christensen, Allen H.; Smith, Gregory A.; O'Leary, David R.; Fram, Miranda S.; Joseph, Trevor; Shannon, Heather


    About 1.02 x 106 m3 of chlorinated municipal drinking water was injected into a confined aquifer, 94-137 m below Roseville, California, between December 2005 and April 2006. The water was stored in the aquifer for 438 days, and 2.64 x 106 m3 of water were extracted between July 2007 and February 2008. On the basis of Cl data, 35% of the injected water was recovered and 65% of the injected water and associated disinfection by-products (DBPs) remained in the aquifer at the end of extraction. About 46.3 kg of total trihalomethanes (TTHM) entered the aquifer with the injected water and 37.6 kg of TTHM were extracted. As much as 44 kg of TTHMs remained in the aquifer at the end of extraction because of incomplete recovery of injected water and formation of THMs within the aquifer by reactions with freechlorine in the injected water. Well-bore velocity log data collected from the Aquifer Storage Recovery (ASR) well show as much as 60% of the injected water entered the aquifer through a 9 m thick, high-permeability layer within the confined aquifer near the top of the screened interval. Model simulations of ground-water flow near the ASR well indicate that (1) aquifer heterogeneity allowed injected water to move rapidly through the aquifer to nearby monitoring wells, (2) aquifer heterogeneity caused injected water to move further than expected assuming uniform aquifer properties, and (3) physical clogging of high-permeability layers is the probable cause for the observed change in the distribution of borehole flow. Aquifer heterogeneity also enhanced mixing of native anoxic ground water with oxic injected water, promoting removal of THMs primarily through sorption. A 3 to 4-fold reduction in TTHM concentrations was observed in the furthest monitoring well 427 m downgradient from the ASR well, and similar magnitude reductions were observed in depth-dependent water samples collected from the upper part of the screened interval in the ASR well near the end of the extraction

  3. Review of Aquifer Storage and Recovery Performance in the Upper Floridan Aquifer in Southern Florida (United States)

    Reese, Ronald S.


    Introduction: Interest and activity in aquifer storage and recovery (ASR) in southern Florida has increased greatly during the past 10 to 15 years. ASR wells have been drilled to the carbonate Floridan aquifer system at 30 sites in southern Florida, mostly by local municipalities or counties located in coastal areas. The primary storage zone at these sites is contained within the brackish to saline Upper Floridan aquifer of the Floridan aquifer system. The strategy for use of ASR in southern Florida is to store excess freshwater available during the wet season in an aquifer and recover it during the dry season when needed for supplemental water supply. Each ASR cycle is defined by three periods: recharge, storage, and recovery. This fact sheet summarizes some of the findings of a second phase retrospective assessment of existing ASR facilities and sites.

  4. Geochemical characterization and heavy metal migration in a coastal polluted aquifer incorporating tidal effects: field investigation in Chongming Island, China. (United States)

    Liu, Shuguang; Tan, Bo; Dai, Chaomeng; Lou, Sha; Tao, An; Zhong, Guihui


    The occurrence and migration of heavy metal in coastal aquifer incorporating tidal effects were investigated in detail by the field geological survey and observation. The continuous groundwater sampling, field observation (for groundwater potentiometric surface elevation, pH, dissolved oxygen, temperature, and salinity), and laboratory analysis (for Cr, Ni, Cu, Zn, Cd, and Pb concentration) were conducted through eight monitoring wells located around the landfill in the northern part of Chongming Island, China. The results showed that the unconfined aquifer medium was estuary-littoral facies deposit of Holocene, mainly gray clayey silt and grey sandy silt, and the groundwater flow was mainly controlled by topography condition of the aquifer formation strike. The background values of Cr, Ni, Cu, Zn, Cd, and Pb in Chongming Island were 3.10 ± 3.09, 0.81 ± 0.25, 1.48 ± 1.09, 43.32 ± 33.06, 0.08 ± 0.16, and 0.88 ± 1.74 μg/L, respectively. Compared with the groundwater samples around the study area, the drinking water was qualified and was free from the seawater intrusion/estuarine facies contaminant encroachment. Pollutant discharge was reflected in water quality parameters, the Cr and Cu concentrations elevated to the peak of 50.07 and 46.00 μg/L, respectively, and meanwhile specific migration regularity was embodied in observation time series as well as other elements. This migration regularity was not fully identical according to correlations between these analyzed elements. Ambient watery environment, anthropogenic disturbance, regional hydrogeological condition, and biogeochemical reactivity on heavy metals reduced/altered the significance of elements correlation in the migration pathway in coastal aquifer.

  5. Transient well flow in vertically heterogeneous aquifers (United States)

    Hemker, C. J.


    A solution for the general problem of computing well flow in vertically heterogeneous aquifers is found by an integration of both analytical and numerical techniques. The radial component of flow is treated analytically; the drawdown is a continuous function of the distance to the well. The finite-difference technique is used for the vertical flow component only. The aquifer is discretized in the vertical dimension and the heterogeneous aquifer is considered to be a layered (stratified) formation with a finite number of homogeneous sublayers, where each sublayer may have different properties. The transient part of the differential equation is solved with Stehfest's algorithm, a numerical inversion technique of the Laplace transform. The well is of constant discharge and penetrates one or more of the sublayers. The effect of wellbore storage on early drawdown data is taken into account. In this way drawdowns are found for a finite number of sublayers as a continuous function of radial distance to the well and of time since the pumping started. The model is verified by comparing results with published analytical and numerical solutions for well flow in homogeneous and heterogeneous, confined and unconfined aquifers. Instantaneous and delayed drainage of water from above the water table are considered, combined with the effects of partially penetrating and finite-diameter wells. The model is applied to demonstrate that the transient effects of wellbore storage in unconfined aquifers are less pronounced than previous numerical experiments suggest. Other applications of the presented solution technique are given for partially penetrating wells in heterogeneous formations, including a demonstration of the effect of decreasing specific storage values with depth in an otherwise homogeneous aquifer. The presented solution can be a powerful tool for the analysis of drawdown from pumping tests, because hydraulic properties of layered heterogeneous aquifer systems with

  6. Vulnerable, But Why? Post-Traumatic Stress Symptoms in Older Adults Exposed to Hurricane Sandy. (United States)

    Heid, Allison R; Christman, Zachary; Pruchno, Rachel; Cartwright, Francine P; Wilson-Genderson, Maureen


    Drawing on pre-disaster, peri-disaster, and post-disaster data, this study examined factors associated with the development of post-traumatic stress disorder (PTSD) symptoms in older adults exposed to Hurricane Sandy. We used a sample of older participants matched by gender, exposure, and geographic region (N=88, mean age=59.83 years) in which one group reported clinically significant levels of PTSD symptoms and the other did not. We conducted t-tests, chi-square tests, and exact logistic regressions to examine differences in pre-disaster characteristics and peri-disaster experiences. Older adults who experienced PTSD symptoms reported lower levels of income, positive affect, subjective health, and social support and were less likely to be working 4 to 6 years before Hurricane Sandy than were people not experiencing PTSD symptoms. Those developing PTSD symptoms reported more depressive symptoms, negative affect, functional disability, chronic health conditions, and pain before Sandy and greater distress and feelings of danger during Hurricane Sandy. Exact logistic regression revealed independent effects of preexisting chronic health conditions and feelings of distress during Hurricane Sandy in predicting PTSD group status. Our findings indicated that because vulnerable adults can be identified before disaster strikes, the opportunity to mitigate disaster-related PTSD exists through identification and resource programs that target population subgroups. (Disaster Med Public Health Preparedness. 2016;10:362-370).

  7. Genesis of Hurricane Sandy (2012) Simulated with a Global Mesoscale Model (United States)

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


    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.

  8. The impact of Hurricane Sandy on the mental health of New York area residents. (United States)

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


    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.

  9. A Black Hills-Madison Aquifer origin for Dakota Aquifer groundwater in northeastern Nebraska. (United States)

    Stotler, Randy; Harvey, F Edwin; Gosselin, David C


    Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migration into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis ((18)O, (2)H, (3)H, (14)C, (13)C, (34)S, (18)O-SO(4), (87)Sr, (37)Cl). Results show that groundwater beneath the eastern, unconfined portion of the study area is distinctly different from groundwater sampled beneath the western, confined portion. In the east, groundwater is calcium-bicarbonate type, with delta(18)O values (-9.6 per thousand to -12.4 per thousand) similar to local, modern precipitation (-7.4 per thousand to -10 per thousand), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted delta(18)O values (-16 per thousand to -18 per thousand) relative to local, modern precipitation, and (14)C ages 32,000 to more than 47,000 years before present. Sulfate, delta(18)O, delta(2)H, delta(34)S, and delta(18)O-SO(4) concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proposed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Nebraska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrepancies between (14)C and Darcy age estimates indicate that (14)C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water.

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

    International Nuclear Information System (INIS)

    Ben Ammar, Safouan


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

  11. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    Directory of Open Access Journals (Sweden)

    Antônio Ocimar Manzi


    Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

  12. Groundwater vulnerability mapping of Qatar aquifers (United States)

    Baalousha, Husam Musa


    Qatar is one of the most arid countries in the world with limited water resources. With little rainfall and no surface water, groundwater is the only natural source of fresh water in the country. Whilst the country relies mainly on desalination of seawater to secure water supply, groundwater has extensively been used for irrigation over the last three decades, which caused adverse environmental impact. Vulnerability assessment is a widely used tool for groundwater protection and land-use management. Aquifers in Qatar are carbonate with lots of fractures, depressions and cavities. Karst aquifers are generally more vulnerable to contamination than other aquifers as any anthropogenic-sourced contaminant, especially above a highly fractured zone, can infiltrate quickly into the aquifer and spread over a wide area. The vulnerability assessment method presented in this study is based on two approaches: DRASTIC and EPIK, within the framework of Geographical Information System (GIS). Results of this study show that DRASTIC vulnerability method suits Qatar hydrogeological settings more than EPIK. The produced vulnerability map using DRASTIC shows coastal and karst areas have the highest vulnerability class. The southern part of the country is located in the low vulnerability class due to occurrence of shale formation within aquifer media, which averts downward movement of contaminants.

  13. Quantum Temporal Imaging


    Tsang, Mankei; Psaltis, Demetri


    The concept of quantum temporal imaging is proposed to manipulate the temporal correlation of entangled photons. In particular, we show that time correlation and anticorrelation can be converted to each other using quantum temporal imaging.

  14. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil. (United States)

    Zhuang, Wenhua; Li, Longguo; Liu, Chao


    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%.

  15. A study on the aseismic safety of the experimental VHTR on the dense sandy layer

    International Nuclear Information System (INIS)

    Fujita, Shigeki; Ito, Yoshio; Baba, Osamu; Suzuki, Hideyuki; Takewaki, Naonobu; Kondo, Tsukasa; Yoshimura, Takashi; Yamada, Hitoshi.


    A series of studies has been carried out in 1983 and 1985 for the purpose of confirming the aseismic safety of the Experimental VHTR on the dense sandy layer. In 1983, effect of some of soil properties on seismic responses of the reactor building was estimated by means of parametric survey, and soil properties were estimated by analyzing the obserbed earthquake record. In 1985, literature review, linear, nonlinear parametric analyses and nonlinear simulation analyses were carried to study and compare the analysis method. In addition, seismic response of proposed construction site was estimated with nonlinear analysis method. As a result of these studies, the seismic response of reactor building on the dense sandy layers and wave propagation characteristics of sandy layers are understood. Especially, by means of many parametric studies, the effect of input wave characteristics, soil stiffness, nonlinear characteristics of soil properties and nonlinear analysis method on the reactor building responses were evaluated. (author)

  16. Analysis of storm-tide impacts from Hurricane Sandy in New York (United States)

    Schubert, Christopher E.; Busciolano, Ronald J.; Hearn, Paul P.; Rahav, Ami N.; Behrens, Riley; Finkelstein, Jason S.; Monti, Jack; Simonson, Amy E.


    The hybrid cyclone-nor’easter known as Hurricane Sandy affected the mid-Atlantic and northeastern United States during October 28-30, 2012, causing extensive coastal flooding. Prior to storm landfall, the U.S. Geological Survey (USGS) deployed a temporary monitoring network from Virginia to Maine to record the storm tide and coastal flooding generated by Hurricane Sandy. This sensor network augmented USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent monitoring sites that also documented storm surge. Continuous data from these networks were supplemented by an extensive post-storm high-water-mark (HWM) flagging and surveying campaign. The sensor deployment and HWM campaign were conducted under a directed mission assignment by the Federal Emergency Management Agency (FEMA). The need for hydrologic interpretation of monitoring data to assist in flood-damage analysis and future flood mitigation prompted the current analysis of Hurricane Sandy by the USGS under this FEMA mission assignment.

  17. What would happen to Superstorm Sandy under the influence of a substantially warmer Atlantic Ocean? (United States)

    Lau, William K. M.; Shi, J. J.; Tao, W. K.; Kim, K. M.


    Based on ensemble numerical simulations, we find that possible responses of Sandy-like superstorms under the influence of a substantially warmer Atlantic Ocean bifurcate into two groups. In the first group, storms are similar to present-day Sandy from genesis to extratropical transition, except they are much stronger, with peak Power Destructive Index (PDI) increased by 50-80%, heavy rain by 30-50%, and maximum storm size (MSS) approximately doubled. In the second group, storms amplify substantially over the interior of the Atlantic warm pool, with peak PDI increased by 100-160%, heavy rain by 70-180%, and MSS more than tripled compared to present-day Superstorm Sandy. These storms when exiting the warm pool, recurve northeastward out to sea, subsequently interact with the developing midlatitude storm by mutual counterclockwise rotation around each other and eventually amplify into a severe Northeastern coastal storm, making landfall over the extreme northeastern regions from Maine to Nova Scotia.

  18. Superstorm Sandy: How the New York University Psychiatry Residency Training Program Weathered the Storm. (United States)

    Capasso, Rebecca; Adler, Laura


    The teaching hospitals of the New York University psychiatry residency program were evacuated and then closed for a minimum of 3 months in the aftermath of Superstorm Sandy. Faculty and residents were deployed to alternate clinical sites. The authors examine the consequences of Superstorm Sandy and its implications for the New York University psychiatry residency training program. A survey was administered to faculty and residents. The authors tabulated 98 surveys, for which 24 % of faculty and 84 % of residents responded. Among respondents, 61 % believed that being involved in the evacuation of the hospitals was a positive experience. During deployment, most (85 %) found being placed with peers and supervisors to be beneficial, but there were significant disruptions. Despite facing multiple challenges including closed facilities, deployment to nonaffiliated hospitals, and exhausted personal resources, the training program continued to provide accredited clinical experiences, a core curriculum, and supervision for psychiatry residents during and after Superstorm Sandy.

  19. Natural dissolved organic matter dynamics in karstic aquifer: O'Leno Sink-Rise system, Florida, USA (United States)

    Jin, J.; Zimmerman, A. R.


    Natural dissolved organic matter (NDOM) dynamics in karstic aquifer remain poorly understood due to the inaccessibility and heterogeneity of the subsurface. Because the Santa Fe River sinks into the Floridan Aquifer and emerges 6 km down gradient, the O'Leno Sink-Rise system in Northern Florida provides an ideal setting to study NDOM transformation in groundwater. Water samples were collected at both high and low temporal resolutions over 3 years from the River Sink, Rise, and a series of shallow and deep wells. Analyses of dissolved organic and inorganic carbon, stable isotopic, and spectrophotometry (excitation-emission matrix or EEM) show that reversals of hydrologic head gradient in the conduit and matrix are closely related to the delivery of NDOM to the aquifer. In addition, the relative influence of biotic and abiotic processes varies along spatiotemporal gradients; regions of the aquifer with greatest connectivity to surface water (new NDOM and terminal electron acceptor supply) see the most microbial transformation of NDOM, while those with least connectivity see relatively greater abiotic transformation of NDOM. A source water mixing model was established for the Sink-Rise system using Mg2+ and SO42- concentrations from three end-members identified as allogenic recharge, upwelling deep water, and shallow groundwater of the Upper Floridan Aquifer. Biogeochemical processes were quantified after accounting for changes that occurred due to source water mixing, according to the model. In addition to NDOM remineralization by subsurface microbes which occurred mostly during wet periods, adsorption of NDOM onto aquifer materials as well as release of NDOM from aquifer materials was also observed. During wet periods when DOC-rich conduit water entered the matrix, progressive NDOM remineralization was found along the preferential flow paths from the conduits into the matrices. Both biotic and abiotic NDOM transformation processes were found to control channel

  20. Spatial patterns and natural recruitment of native shrubs in a semi-arid sandy land. (United States)

    Wu, Bo; Yang, Hongxiao


    Passive restoration depending on native shrubs is an attractive approach for restoring desertified landscapes in semi-arid sandy regions. We sought to understand the relationships between spatial patterns of native shrubs and their survival ability in sandy environments. Furthermore, we applied our results to better understand whether passive restoration is feasible for desertified landscapes in semi-arid sandy regions. The study was conducted in the semi-arid Mu Us sandy land of northern China with the native shrub Artemisia ordosica. We analyzed population structures and patterns of A. ordosica at the edges and centers of land patches where sand was stabilized by A. ordosica-dominated vegetation. Saplings were more aggregated than adults, and both were more aggregated at the patch edges than at the patch centers. At the patch edges, spatial association of the saplings with the adults was mostly positive at distances 0.3-6.6 m, and turned from positive to neutral, and even negative, at other distances. At the patch centers, the saplings were spaced almost randomly around the adults, and their distances from the adults did not seem to affect their locations. A greater number of A. ordosica individuals emerged at the patch edges than at the patch centers. Such patterns may have resulted from their integrative adjustment to specific conditions of soil water supply and sand drift intensity. These findings suggest that in semi-arid sandy regions, native shrubs that are well-adapted to local environments may serve as low-cost and competent ecological engineers that can promote the passive restoration of surrounding patches of mobile sandy land.

  1. Numerical modeling of salt marsh morphological change induced by Hurricane Sandy (United States)

    Hu, Kelin; Chen, Qin; Wang, Hongqing; Hartig, Ellen K.; Orton, Philip M.


    The salt marshes of Jamaica Bay serve as a recreational outlet for New York City residents, mitigate wave impacts during coastal storms, and provide habitat for critical wildlife species. Hurricanes have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. In this study, the Delft3D modeling suite was utilized to examine the effects of Hurricane Sandy (2012) on salt marsh morphology in Jamaica Bay. Observed marsh elevation change and accretion from rod Surface Elevation Tables and feldspar Marker Horizons (SET-MH) and hydrodynamic measurements during Hurricane Sandy were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model. The model results agreed well with in situ field measurements. The validated model was then used to detect salt marsh morphological change due to Sandy across Jamaica Bay. Model results indicate that the island-wide morphological changes in the bay's salt marshes due to Sandy were in the range of −30 mm (erosion) to +15 mm (deposition), and spatially complex and heterogeneous. The storm generated paired deposition and erosion patches at local scales. Salt marshes inside the west section of the bay showed erosion overall while marshes inside the east section showed deposition from Sandy. The net sediment amount that Sandy brought into the bay is only about 1% of the total amount of reworked sediment within the bay during the storm. Numerical experiments show that waves and vegetation played a critical role in sediment transport and associated wetland morphological change in Jamaica Bay. Furthermore, without the protection of vegetation, the marsh islands of Jamaica Bay would experience both more erosion and less accretion in coastal storms.

  2. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

    Energy Technology Data Exchange (ETDEWEB)

    Levi, S.; Hybel, A.-M.; Bjerg, P.L.; Albrechtsen, H.-J., E-mail:


    In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential for the herbicides. In the presence of oxygen {sup 14}C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added. The highest oxygen concentrations (corresponding to 4–11 mg L{sup −1}) stimulated degradation (a 14–27% increase for mecoprop, 3–9% for dichlorprop and 15–20% for bentazone) over an experimental period of 200 days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2 mg L{sup −1}). The sediment had substantial oxygen consumption (0.92–1.45 O{sub 2} g{sup -1} dw over 200 days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due to the oxidation of organic matter and other reduced species such as Fe{sup 2+}, S{sup 2−} and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination. - Highlights: • Addition of different oxygen concentrations stimulated degradation of

  3. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

    International Nuclear Information System (INIS)

    Levi, S.; Hybel, A.-M.; Bjerg, P.L.; Albrechtsen, H.-J.


    In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential for the herbicides. In the presence of oxygen 14 C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added. The highest oxygen concentrations (corresponding to 4–11 mg L −1 ) stimulated degradation (a 14–27% increase for mecoprop, 3–9% for dichlorprop and 15–20% for bentazone) over an experimental period of 200 days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2 mg L −1 ). The sediment had substantial oxygen consumption (0.92–1.45 O 2 g -1 dw over 200 days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due to the oxidation of organic matter and other reduced species such as Fe 2+ , S 2− and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination. - Highlights: • Addition of different oxygen concentrations stimulated degradation of herbicides in anaerobic aquifer sediment

  4. Groundwaters of Florence (Italy): Trace element distribution and vulnerability of the aquifers (United States)

    Bencini, A.; Ercolanelli, R.; Sbaragli, A.; Verrucchi, C.


    Geochemical and hydrogeological research has been carried out on 109 wells in the alluvial plain of Florence, in order to evaluate conductivity and main chemistry of ground waters, the pattern of some possible pollutant chemical species (Fe, Mn, Cr, Cu, Pb, Zn, NO2, NO3), and the vulnerability of the aquifers. The plain is made up of Plio-Quaternary alluvial and lacustrine sediments for a maximum thickness of 600 m. Silts and clays, sometimes with lenses of sandy gravels, are dominant, while considerable deposits of sands, pebbles, and gravels occur along the course of the Arno river and its tributary streams, and represent the most important aquifer of the plain. The groundwaters analyzed belong to this aquifer or to the smaller ones, hosted in the gravel lenses. Most waters show conductivity values around 1000 1200 μS, and almost all of them have an alkaline-earth-bicarbonate chemical character; these features are consistent with the mainly calcareous lithology of the aquifers. In the western areas a higher salt content of the groundwaters is evident, probably related to the presence of industrial activities which use water desalinators. Heavy metal and NO2, NO3 analyses point out that no important pollution phenomena affect the groundwaters; all the mean values of the chemical considered species are below the maximum admissible concentration (MAC) fixed by the European Community for drinkable waters. Nevertheless, some anomalies of NO2, NO3, Fe, Mn, and Zn are present in the plain. Apart from Mn, which seems to be released by certain calcareous gravels, the other anomalies have a local influence, since they disappear even in the nearest wells. The most plausible causes can be recognized in losses of the sewage system (NO2=3 4 mg/t); use of nitrate compounds in agriculture (NO3=60 70 mg/l); oxidation of well pipes (Fe ≈ 20 mg/l; Zn ≈ 6 mg/l). As regards Cr, Cu, and Pb, all the observations are below the MAC; therefore, the median values of bacteria oxidation

  5. Acid groundwater in an anoxic aquifer: Reactive transport modelling of buffering processes

    International Nuclear Information System (INIS)

    Franken, Gudrun; Postma, Dieke; Duijnisveld, Wilhelmus H.M.; Boettcher, Juergen; Molson, John


    The acidification of groundwater, due to acid rain, was investigated in a Quaternary sandy aquifer in the Fuhrberger Feld, near Hannover, Germany. The groundwater, recharged through an area covered by a coniferous forest, had a pH in the range 4-5 down to a depth of 5 m. The evolution in groundwater chemistry along the flow path was investigated in a transect of multisamplers. A 2D groundwater flow model was established delineating the groundwater flow field and a groundwater flow velocity of around 80 m/a along the flow path was derived. Speciation calculations showed the groundwater to be close to equilibrium with the mineral jurbanite (AlOHSO 4 ) over the pH range 4.0-6.5. This suggests an accumulation of acid rain derived SO 4 2- in the aquifer sediment during the decades with high atmospheric S deposition. The groundwater has a pH of around 4.5 in the upstream part of the flow path increasing to near 6 further downstream. 1D reactive transport modelling, using PHREEQC, was used to analyze different combinations of buffering processes. The first model contains ion exchange in combination with jurbanite dissolution. At the ion exchange front Al 3+ is adsorbed leading to the dissolution of jurbanite and an increase in pH. Comparison with field data showed that the simulated increases in pH and alkalinity are much lower than observed in the field. The second model includes organic matter degradation. In addition to ion exchange and jurbanite dissolution, the model included the reduction of SO 4 2- and Fe-oxides as well as the precipitation of Fe sulfide. This model matches the field data well and illustrates the importance of redox processes for pH buffering in the Fuhrberg aquifer. The current progress of the acidification front is about 4 m/a. This corresponds to an average value of 150 a of acid input, which covers large historical variations. Remediation is expected to take the same time span because it requires desorption and neutralization of adsorbed Al 3

  6. Groundwaters of Florence (Italy): Trace element distribution and vulnerability of the aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Bencini, A.; Ercolanelli, R.; Sbaragli, A. [Univ. of Florence (Italy)] [and others


    Geochemical and hydrogeological research has been carried out in Florence, to evaluate conductivity and main chemistry of groundwaters, the pattern of some possible pollutant chemical species (Fe, Mn, Cr, Cu, Pb, Zn, NO{sub 2}, NO{sub 3}), and the vulnerability of the aquifers. The plain is made up of Plio-Quaternary alluvial and lacustrine sediments for a maximum thickness of 600 m. Silts and clays, sometimes with lenses of sandy gravels, are dominant, while considerable deposits of sands, pebbles, and gravels occur along the course of the Arno river and its tributary streams, and represent the most important aquifer of the plain. Most waters show conductivity values around 1000-1200 {mu}S, and almost all of them have an alkaline-earth-bicarbonate chemical character. In western areas higher salt content of the groundwaters is evident. Heavy metal and NO{sub 2}, NO{sub 3} analyses point out that no important pollution phenomena affect the groundwaters; all mean values are below the maximum admissible concentration (MAC) for drinkable waters. Some anomalies of NO{sub 2}, NO{sub 3}, Fe, Mn, and Zn are present. The most plausible causes can be recognized in losses of the sewage system; use of nitrate compounds in agriculture; oxidation of well pipes. All the observations of Cr, Cu, and Pb are below the MAC; the median values of <3, 3.9, and 1.1 {mu}g/l, respectively, could be considered reference concentrations for groundwaters in calcareous lithotypes, under undisturbed natural conditions. Finally, a map of vulnerability shows that the areas near the Arno river are highly vulnerable, for the minimum thickness (or lacking) of sediments covering the aquifer. On the other hand, in the case of pollution, several factors not considered could significantly increase the self-purification capacity of the aquifer, such asdilution of groundwaters, bacteria oxidation of nitrogenous species, and sorption capacity of clay minerals and organic matter. 31 refs., 6 figs., 5 tabs.

  7. 40 CFR 147.502 - Aquifer exemptions. [Reserved (United States)


    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Aquifer exemptions. [Reserved] 147.502... (CONTINUED) STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS Florida § 147.502 Aquifer exemptions. [Reserved] ...

  8. Simulation of seawater intrusion in coastal aquifers: Some typical ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Seawater intrusion; coastal aquifers; density-dependent flow and ... The seawater intrusion mechanism in coastal aquifers generally causes the occurrence of ... (4) The dynamic viscosity of the fluid does not change with respect to salinity and.

  9. Ground Water movement in crystalline rock aquifers

    International Nuclear Information System (INIS)

    Serejo, A.N.C.; Freire, C.; Siqueira, H.B. de; Frischkorn, H.; Torquato, J.R.F.; Santiago, M.M.F.; Barbosa, P.C.


    Ground water movement studies were performed in crystalline rock aquifers from the upper Acarau River hydrographic basin, state of Ceara, Brazil. The studies included carbon-14, 18 O/ 16 O and tritium measurements as well as chemical analysis. A total of 35 wells were surveyed during drought seasons. Carbon-14 values displayed little variation which implied that the water use was adequate despite of the slower recharge conditions. Fairly constant isotopic 18 O/ 16 O ratio values in the wells and their similarity with rainwater values indicated that the recharge is done exclusively by pluvial waters. A decreasing tendency within the tritium concentration values were interpreted as a periodic rainwater renewal for these aquifers. The chemical analysis demonstrated that there is in fact no correlation between salinity and the time the water remains in the aquifer itself. (D.J.M.) [pt

  10. Determination of diffusion coefficients in cohesive and sandy sediment from the area of Gorleben

    International Nuclear Information System (INIS)

    Klotz, D.


    The cohesive and sandy sediments stem from shaft driving at the Gorleben salt done. For the cohesive materials, HTD was used as a tracer substance, while I-131 - was used for the sandy materials. Diffusion coefficients of HTD in cohesive materials in their natural texture are in the range of 2x10 -6 to 5x10 -6 cm 2 /s, those of I-131 - in the investigated uniform fine and middle sands are approximately 3x10 -6 cm 2 /s. (DG) [de

  11. Unconsolidated Aquifers in Tompkins County, New York (United States)

    Miller, Todd S.


    Unconsolidated aquifers consisting of saturated sand and gravel are capable of supplying large quantities of good-quality water to wells in Tompkins County, but little published geohydrologic inform ation on such aquifers is available. In 1986, the U.S.Geological Survey (USGS) began collecting geohydrologic information and well data to construct an aquifer map showing the extent of unconsolidated aquifers in Tompkins county. Data sources included (1) water-well drillers. logs; (2) highway and other construction test-boring logs; (3) well data gathered by the Tompkins County Department of Health, (4) test-well logs from geohydrologic consultants that conducted projects for site-specific studies, and (5) well data that had been collected during past investigations by the USGS and entered into the National Water Information System (NWIS) database. In 1999, the USGS, in cooperation with the Tompkins County Department of Planning, compiled these data to construct this map. More than 600 well records were entered into the NWIS database in 1999 to supplement the 350 well records already in the database; this provided a total of 950 well records. The data were digitized and imported into a geographic information system (GIS) coverage so that well locations could be plotted on a map, and well data could be tabulated in a digital data base through ARC/INFO software. Data on the surficial geology were used with geohydrologic data from well records and previous studies to delineate the extent of aquifers on this map. This map depicts (1) the extent of unconsolidated aquifers in Tompkins County, and (2) locations of wells whose records were entered into the USGS NWIS database and made into a GIS digital coverage. The hydrologic information presented here is generalized and is not intended for detailed site evaluations. Precise locations of geohydrologic-unit boundaries, and a description of the hydrologic conditions within the units, would require additional detailed, site

  12. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)



    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  13. Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Sobocinski, Kathryn; Johnson, Gary; Sather, Nichole [Pacific Northwest National Laboratory


    ) Determine fish community characteristics, including species composition, abundance, and temporal and spatial distributions. (1c) Estimate the stock of origin for the yearling and subyearling Chinook salmon captured at the sampling sites using genetic analysis. (1d) Statistically assess the relationship between salmonid abundance and habitat parameters, including ancillary variables such as temperature and river stage. (2) Acoustic Telemetry Monitoring-Assess feasibility of applying Juvenile Salmon Acoustic Telemetry System (JSATS) technology to determine migration characteristics from upriver of Bonneville Dam through the study area (vicinity of the Sandy River delta/Washougal River confluence). (2a) Determine species composition, release locations, and distributions of JSATS-tagged fish. (2b) Estimate run timing, residence times, and migration pathways for these fish. Additionally, both objectives serve the purpose of baseline research for a potential tidal rechannelization project on the Sandy River. The U.S. Forest Service, in partnership with the Bonneville Power Administration and the U.S. Army Corps of Engineers, is currently pursuing reconnection of the east (relict) Sandy River channel with the current channel to improve fish and wildlife habitat in the Sandy River delta. Our study design and the location of sampling sites in this reach provide baseline data to evaluate the potential restoration.

  14. Comparison of groundwater flow in Southern California coastal aquifers (United States)

    Hanson, Randall T.; Izbicki, John A.; Reichard, Eric G.; Edwards, Brian D.; Land, Michael; Martin, Peter


    Development of the coastal aquifer systems of Southern California has resulted in overdraft, changes in streamflow, seawater intrusion, land subsidence, increased vertical flow between aquifers, and a redirection of regional flow toward pumping centers. These water-management challenges can be more effectively addressed by incorporating new understanding of the geologic, hydrologic, and geochemical setting of these aquifers.

  15. Replacement of Eocene white sandy limestone in historical buildings : over 100 years of practice in the Netherlands

    NARCIS (Netherlands)

    Quist, W.J.; Nijland, T.G.; Hees, R.P.J. van


    This paper discusses the replacement of white sandy limestone (Gobertange and Lede or Balegem) in the Netherlands in (successive) restorations from the mid-19th century onwards. White sandy limestone, transported from the southern part of the Low Countries (now Belgium), was extensively used in the

  16. Characterizing Heterogeneity in Infiltration Rates During Managed Aquifer Recharge. (United States)

    Mawer, Chloe; Parsekian, Andrew; Pidlisecky, Adam; Knight, Rosemary


    Infiltration rate is the key parameter that describes how water moves from the surface into a groundwater aquifer during managed aquifer recharge (MAR). Characterization of infiltration rate heterogeneity in space and time is valuable information for MAR system operation. In this study, we utilized fiber optic distributed temperature sensing (FO-DTS) observations and the phase shift of the diurnal temperature signal between two vertically co-located fiber optic cables to characterize infiltration rate spatially and temporally in a MAR basin. The FO-DTS measurements revealed spatial heterogeneity of infiltration rate: approximately 78% of the recharge water infiltrated through 50% of the pond bottom on average. We also introduced a metric for quantifying how the infiltration rate in a recharge pond changes over time, which enables FO-DTS to be used as a method for monitoring MAR and informing maintenance decisions. By monitoring this metric, we found high-spatial variability in how rapidly infiltration rate changed during the test period. We attributed this variability to biological pore clogging and found a relationship between high initial infiltration rate and the most rapid pore clogging. We found a strong relationship (R 2  = 0.8) between observed maximum infiltration rates and electrical resistivity measurements from electrical resistivity tomography data taken in the same basin when dry. This result shows that the combined acquisition of DTS and ERT data can improve the design and operation of a MAR pond significantly by providing the critical information needed about spatial variability in parameters controlling infiltration rates. © 2016, National Ground Water Association.

  17. Aquifer geochemistry at potential aquifer storage and recovery sites in coastal plain aquifers in the New York city area, USA (United States)

    Brown, C.J.; Misut, P.E.


    The effects of injecting oxic water from the New York city (NYC) drinking-water supply and distribution system into a nearby anoxic coastal plain aquifer for later recovery during periods of water shortage (aquifer storage and recovery, or ASR) were simulated by a 3-dimensional, reactive-solute transport model. The Cretaceous aquifer system in the NYC area of New York and New Jersey, USA contains pyrite, goethite, locally occurring siderite, lignite, and locally varying amounts of dissolved Fe and salinity. Sediment from cores drilled on Staten Island and western Long Island had high extractable concentrations of Fe, Mn, and acid volatile sulfides (AVS) plus chromium-reducible sulfides (CRS) and low concentrations of As, Pb, Cd, Cr, Cu and U. Similarly, water samples from the Lloyd aquifer (Cretaceous) in western Long Island generally contained high concentrations of Fe and Mn and low concentrations of other trace elements such as As, Pb, Cd, Cr, Cu and U, all of which were below US Environmental Protection Agency (USEPA) and NY maximum contaminant levels (MCLs). In such aquifer settings, ASR operations can be complicated by the oxidative dissolution of pyrite, low pH, and high concentrations of dissolved Fe in extracted water.The simulated injection of buffered, oxic city water into a hypothetical ASR well increased the hydraulic head at the well, displaced the ambient groundwater, and formed a spheroid of injected water with lower concentrations of Fe, Mn and major ions in water surrounding the ASR well, than in ambient water. Both the dissolved O2 concentrations and the pH of water near the well generally increased in magnitude during the simulated 5-a injection phase. The resultant oxidation of Fe2+ and attendant precipitation of goethite during injection provided a substrate for sorption of dissolved Fe during the 8-a extraction phase. The baseline scenario with a low (0.001M) concentration of pyrite in aquifer sediments, indicated that nearly 190% more water

  18. Towards General Temporal Aggregation

    DEFF Research Database (Denmark)

    Boehlen, Michael H.; Gamper, Johann; Jensen, Christian Søndergaard


    associated with the management of temporal data. Indeed, temporal aggregation is complex and among the most difficult, and thus interesting, temporal functionality to support. This paper presents a general framework for temporal aggregation that accommodates existing kinds of aggregation, and it identifies...

  19. Investigating river–aquifer relations using water temperature in an anthropized environment (Motril-Salobreña aquifer)

    DEFF Research Database (Denmark)

    Duque, Carlos; Calvache, Marie; Engesgaard, Peter Knudegaard


    Heat was applied as a tracer for determining river–aquifer relations in the Motril-Salobreña aquifer (S Spain). The aquifer has typically been recharged by River Guadalfeo infiltration, nevertheless from 2005 a dam was constructed changing the traditional dynamic river flow and recharge events...

  20. Hydrological controls on transient aquifer storage in a karst watershed (United States)

    Spellman, P.; Martin, J.; Gulley, J. D.


    While surface storage of floodwaters is well-known to attenuate flood peaks, transient storage of floodwaters in aquifers is a less recognized mechanism of flood peak attenuation. The hydraulic gradient from aquifer to river controls the magnitude of transient aquifer storage and is ultimately a function of aquifer hydraulic conductivity, and effective porosity. Because bedrock and granular aquifers tend to have lower hydraulic conductivities and porosities, their ability to attenuate flood peaks is generally small. In karst aquifers, however, extensive cave systems create high hydraulic conductivities and porosities that create low antecedent hydraulic gradients between aquifers and rivers. Cave springs can reverse flow during high discharges in rivers, temporarily storing floodwaters in the aquifer thus reducing the magnitude of flood discharge downstream. To date however, very few studies have quantified the magnitude or controls of transient aquifer storage in karst watersheds. We therefore investigate controls on transient aquifer storage by using 10 years of river and groundwater data from the Suwannee River Basin, which flows over the karstic upper Floridan aquifer in north-central Florida. We use multiple linear regression to compare the effects of three hydrological controls on the magnitude of transient aquifer storage: antecedent stage, recharge and slope of hydrograph rise. We show the dominant control on transient aquifer storage is antecedent stage, whereby lower stages result in greater magnitudes of transient aquifer storage. Our results suggest that measures of groundwater levels prior to an event can be useful in determining whether transient aquifer storage will occur and may provide a useful metric for improving predictions of flood magnitudes.

  1. Can Remote Sensing Detect Aquifer Characteristics?: A Case Study in the Guarani Aquifer System (United States)

    Richey, A. S.; Thomas, B.; Famiglietti, J. S.


    Global water supply resiliency depends on groundwater, especially regions threatened by population growth and climate change. Aquifer characteristics, even as basic as confined versus unconfined, are necessary to prescribe regulations to sustainably manage groundwater supplies. A significant barrier to sustainable groundwater management exists in the difficulties associated with mapping groundwater resources and characteristics at a large spatial scale. This study addresses this challenge by investigating if remote sensing, including with NASA's Gravity Recovery and Climate Experiment (GRACE), can detect and quantify key aquifer parameters and characteristics. We explore this through a case study in the Guarani Aquifer System (GAS) of South America, validating our remote sensing-based findings against the best available regional estimates. The use of remote sensing to advance the understanding of large aquifers is beneficial to sustainable groundwater management, especially in a trans-boundary system, where consistent information exchange can occur within hydrologic boundaries instead of political boundaries.

  2. State Aquifer Recharge Atlas Plates, Geographic NAD83, LDEQ (1999) [aquifer_recharge_potential_LDEQ_1988 (United States)

    Louisiana Geographic Information Center — This is a polygon dataset depicting the boundaries of aquifer systems in the state of Louisiana and adjacent areas of Texas, Arkansas and a portion of Mississippi....

  3. Hydrogeology, water quality, and saltwater intrusion in the Upper Floridan Aquifer in the offshore area near Hilton Head Island, South Carolina, and Tybee Island, Georgia, 1999-2002 (United States)

    Falls, W. Fred; Ransom, Camille; Landmeyer, James E.; Reuber, Eric J.; Edwards, Lucy E.


    To assess the hydrogeology, water quality, and the potential for saltwater intrusion in the offshore Upper Floridan aquifer, a scientific investigation was conducted near Tybee Island, Georgia, and Hilton Head Island, South Carolina. Four temporary wells were drilled at 7, 8, 10, and 15 miles to the northeast of Tybee Island, and one temporary well was drilled in Calibogue Sound west of Hilton Head Island. The Upper Floridan aquifer at the offshore and Calibogue sites includes the unconsolidated calcareous quartz sand, calcareous quartz sandstone, and sandy limestone of the Oligocene Lazaretto Creek and Tiger Leap Formations, and the limestone of the late Eocene Ocala Limestone and middle Avon Park Formation. At the 7-, 10-, and 15-mile sites, the upper confining unit between the Upper Floridan and surficial aquifers correlates to the Miocene Marks Head Formation. Paleochannel incisions have completely removed the upper confining unit at the Calibogue site and all but a 0.8-foot-thick interval of the confining unit at the 8-mile site, raising concern about the potential for saltwater intrusion through the paleochannel-fill sediments at these two sites. The paleochannel incisions at the Calibogue and 8-mile sites are filled with fine- and coarse-grained sediments, respectively. The hydrogeologic setting and the vertical hydraulic gradients at the 7- and 10-mile sites favored the absence of saltwater intrusion during predevelopment. After decades of onshore water use in Georgia and South Carolina, the 0-foot contour in the regional cone of depression of the Upper Floridan aquifer is estimated to have been at the general location of the 7- and 10-mile sites by the mid-1950s and at or past the 15-mile site by the 1980s. The upward vertical hydraulic gradient reversed, but the presence of more than 17 feet of upper confining unit impeded the downward movement of saltwater from the surficial aquifer to the Upper Floridan aquifer at the 7- and 10-mile sites. At the 10

  4. Tropical Cyclone Track Convergence Patterns, Arctic Sea-Ice Loss, and Superstorm Sandy: Is There a Connection? (United States)

    Barnes, C. C.; Francis, J. A.; Byrne, J. M.; Graham, J. R.; McDaniel, S. A.


    The potential for disruption to populations and food production due to global climate change will be catastrophic in some regions. Among the most vulnerable regions are those impacted by intensifying or changing tropical cyclones (TC). The objective of this research is to identify historical trends in TC tracks and regional circulation patterns that may forecast increasing risks due to TC intensification under global climate warming. We carry out spatial and temporal analysis of the 1979 - 2011 International Best Track Archive for Climate Stewardship (IBTrACS) historical hurricane database. The data were divided into several subsets to allow analysis of trend in: (i) early (JJAS) and late (OND) seasonal trends; and (ii) multi-year intervals (1979-95 and 1996-2011) to differentiate possible long term trends, if any. Geographical Information Systems (GIS) overlay analysis of the IBTrACS 64 knot hurricane wind radii data identified varying levels of historical tropical cyclone track convergence in the North Atlantic (NA) basin. Results of the track convergence analysis provide a first order analysis regarding changing potential population vulnerabilities due to changing seasonal or long-term tropical cyclone activity. During the summer of 2012, the amount of sea ice on the Arctic Ocean was diminished to about half of its normal extent and 25% of its normal volume relative to the nearly steady conditions that existed before the 1980s. This record loss continues an inexorable decline observed during recent decades. The dramatic increase in open water allows much more solar energy absorption at high latitude. Most of this extra heat returns to the atmosphere in autumn, contributing to the Arctic's rate of warming; exceeding that of mid-latitudes by a factor of two to three, a phenomenon called Arctic Amplification (AA). During October 2012, prior to the arrival of Superstorm Sandy along the eastern seaboard, AA was particularly strong, resulting in a substantial

  5. Nutrient Removal during Stormwater Aquifer Storage and Recovery in an Anoxic Carbonate Aquifer. (United States)

    Vanderzalm, Joanne L; Page, Declan W; Dillon, Peter J; Barry, Karen E; Gonzalez, Dennis


    Stormwater harvesting coupled to managed aquifer recharge (MAR) provides a means to use the often wasted stormwater resource while also providing protection of the natural and built environment. Aquifers can act as a treatment barrier within a multiple-barrier approach to harvest and use urban stormwater. However, it remains challenging to assess the treatment performance of a MAR scheme due to the heterogeneity of aquifers and MAR operations, which in turn influences water treatment processes. This study uses a probabilistic method to evaluate aquifer treatment performance based on the removal of total organic C (TOC), N, and P during MAR with urban stormwater in an anoxic carbonate aquifer. Total organic C, N, and P are represented as stochastic variables and described by probability density functions (PDFs) for the "injectant" and "recovery"; these injectant and recovery PDFs are used to derive a theoretical MAR removal efficiency PDF. Four long-term MAR sites targeting one of two tertiary carbonate aquifers (T1 and T2) were used to describe the nutrient removal efficiencies. Removal of TOC and total N (TN) was dominated by redox processes, with median removal of TOC between 50 and 60% at all sites and TN from 40 to 50% at three sites with no change at the fourth. Total P removal due to filtration and sorption accounted for median removal of 29 to 53%. Thus, the statistical method was able to characterize the capacity of the anoxic carbonate aquifer treatment barrier for nutrient removal, which highlights that aquifers can be an effective long-term natural treatment option for management of water quality, as well as storage of urban stormwater. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil

    KAUST Repository

    Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio


    Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

  7. Enhancing crude oil degradation in a sandy soil: Effects of addition ...

    African Journals Online (AJOL)

    This study investigated the effects of the addition of poultry manure alone and in combination with surfactant (Goldcrew or Corexit) and/or alternate carbon substrate (glucose or starch) on crude oil degradation in a sandy soil. With poultry manure alone, optimal crude oil degradation was obtained at a concentration of 4.0% ...

  8. Transport of water and solutes in wettable and water repellent sandy soils

    NARCIS (Netherlands)

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


    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

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

    African Journals Online (AJOL)


    many regions of the world if the mechanics of tillage effects on soil physical properties is to be well understood. Thus, the ... tillage systems on water storage of a sandy loam soil after 22 years of ..... Soil infiltration ... and processes. Academy ...

  10. Limits to intensity of milk production in sandy areas in The Netherlands

    NARCIS (Netherlands)

    Aarts, H.F.M.; Habekotté, B.; Keulen, van H.


    Agricultural land in sandy areas is mainly in use by dairy farms. As a result of intensive fertilisation and irrigation, environmental quality is threatened by lost nutrients and lowered groundwater levels. Therefore, Dutch government put decreasing limits to losses of nutrients, with lowest values

  11. An analysis of the synoptic and dynamical characteristics of hurricane Sandy (2012) (United States)

    Varlas, George; Papadopoulos, Anastasios; Katsafados, Petros


    Hurricane Sandy affected the Caribbean Islands and the Northeastern United States in October 2012 and caused 233 fatalities, severe rainfalls, floods, electricity blackouts, and 75 billion U.S. dollars in damages. In this study, the synoptic and dynamical characteristics that led to the formation of the hurricane are investigated. The system was driven by the interaction between the polar jet displacement and the subtropical jet stream. In particular, Sandy was initially formed as a tropical depression system over the Caribbean Sea and the unusually warm sea drove its intensification. The interaction between a rapidly approaching trough from the northwest and the stagnant ridge over the Atlantic Ocean drove Sandy to the northeast coast of United States. To better understand the dynamical characteristics and the mechanisms that triggered Sandy, a non-hydrostatic mesoscale model has been used. Model results indicate that the surface heat fluxes and the moisture advection enhanced the convective available potential energy, increased the low-level convective instability, and finally deepened the hurricane. Moreover, the upper air conditions triggered the low-level frontogenesis and increased the asymmetry of the system which finally affected its trajectory.

  12. Effect of soil pH on sorption of salinomycin in clay and sandy soils

    African Journals Online (AJOL)


    The sorption of salinomycin to the sandy soil marginally increased as the pH decreased, while the sorption to the two .... plastic containers at room temperature for further analysis. ... The pH was adjusted eight times over 20 days to stabilize at.

  13. Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil. (United States)

    Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio


    Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils. From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls. Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

  14. Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil

    KAUST Repository

    Raddadi, Noura


    Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

  15. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China (United States)

    Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang


    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...

  16. Assessment of structural stability of a degraded sandy clay loam soil ...

    African Journals Online (AJOL)

    The effects of bare, two legumes and four grasses cover treatments on the structural stability of a sandy clay loam Ultisol were studied within a two year period. The experiment was of a randomised complete block design with seven treatments. The legume treatments were Centrosema pubescens (Ce) and Pueraria ...

  17. Sensitivity analysis of the surface water- groundwater interaction for the sandy area of the Netherlands

    NARCIS (Netherlands)

    Gomez del Campo, E.; Jousma, G.; Massop, H.T.L.


    The "Sensitivity Analysis of the Surface Water- Groundwater Interaction for the Sandy Area of the Netherlands" was carried out in the framework of a bilateral research project in support of the implementation of a nationwide geohydrological information system (REGIS) in the Netherlands. This

  18. 2012 USACE Post Sandy Topographic LiDAR: Virginia and Maryland (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...

  19. 2012 USACE Post Sandy Topographic LiDAR: Eastern Long Island, New York (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588 Woolpert...

  20. Amelioration of sandy soils in drought stricken areas through use of ...

    African Journals Online (AJOL)

    Soil moisture shortage is a major limiting factor to agricultural production in eastern Africa, in view of increased drought incidences and seasonal rainfall variability. This study evaluated the potential for Ca-bentonite (a 2:1 clay mineral) as a possible amendment for increased moisture retention by sandy soils in drought ...

  1. Fine natural aggregate replacement for sandy residue from itabirite exploitation in Portland cement mortar

    International Nuclear Information System (INIS)

    Melo, V.A.R.; Freire, C.B.; Pereira Junior, S.S.; Lameiras, F.S.; Tello, C.C.O.


    The fine natural aggregates are a material largely used by the civil construction for mortar and concrete production. Due to tightening legal restrictions imposed on their extraction, alternative materials are being considered. The use of sandy residue from BIF (banded iron formations) exploitation was investigated. It requires their grinding and flotation to concentrate iron oxides. Large amounts of sandy residue composed of quartz and iron oxides are generated in this process. The sandy residue was characterized relative to mineralogical composition, particle size distribution, presence of organic impurities, and particle shape. Mortar formulations were prepared by varying the type of cement, the cement to aggregate proportion and the water/cement ratio (a/c). The results of viscosity and density of fresh mortar, setting time, and compressive strength are presented. Compressive strength up to 19.5 MPa at 28 days were achieved with the use of cement CPV, a/c ratio of 0.80 and cement:aggregate proportion of 1:2. The results demonstrate the technical feasibility of using sandy residue as fine aggregate. (author)

  2. A new method for measuring bioturbation rates in sandy tidal flat sediments based on luminescence dating

    DEFF Research Database (Denmark)

    Madsen, Anni T.; Murray, Andrew S.; Jain, Mayank


    The rates of post-depositional mixing by bioturbation have been investigated using Optically Stimulated Luminescence (OSL) dating in two sediment cores (BAL2 and BAL5), retrieved from a sandy tidal flat in the Danish part of the Wadden Sea. A high-resolution chronology, consisting of thirty-six OSL...

  3. Storm Impact and Depression Among Older Adults Living in Hurricane Sandy-Affected Areas. (United States)

    Sirey, Jo Anne; Berman, Jacquelin; Halkett, Ashley; Giunta, Nancy; Kerrigan, Janice; Raeifar, Elmira; Artis, Amanda; Banerjee, Samprit; Raue, Patrick J


    Research on the impact of natural disasters on the mental health of older adults finds both vulnerabilities and resilience. We report on the rates of clinically significant depression among older adults (aged ≥60 years) living in areas affected by Hurricane Sandy in 2012 and the factors associated with mental health need. The Sandy Mobilization, Assessment, Referral and Treatment for Mental Health (SMART-MH) program integrates community outreach and needs assessments to identify older adults with mental health and aging service needs. Older adults with significant anxiety or depressive symptoms were offered short-term psychotherapy. Social service referrals were made directly to community agencies. All SMART-MH activities were offered in Spanish, Russian, Mandarin/Cantonese, and English. Across the full sample, 14% of participants screened positive for depression. Hurricane Sandy stressors predicted increased odds of depression, including storm injury, post-storm crime, and the total count of stressors. Outcomes varied significantly by age group, such that all Sandy-related variables remained significant for younger-old adults (aged 60-74 years), whereas only the loss of access to medical care was significant for older-old adults (aged ≥75 years). Storm-affected communities show higher rates of depressive symptoms than seen in the general population, with storm stressors affecting mental health needs differentially by age group. (Disaster Med Public Health Preparedness. 2017;11:97-109).

  4. Toward a Unified Military Response: Hurricane Sandy and the Dual Status Commander (United States)


    18th tropical depression of the season formed over the southwestern Caribbean Sea and quickly strength- ened into Tropical Storm Sandy late that... Centennial , a combined Title 10 and 32 operation, during the Sep- tember 2013 response to the Colorado Floods. 117 APPENDIX I ACRONYMS AAR After Action

  5. Symposium of Hope: Recovery and Resiliency after the Sandy Hook Tragedy. Crisis Management (United States)

    Zenere, Frank J.


    On February 27 and 28, 2013, The Symposium of Hope: Recovery and Resilience after the Sandy Hook Tragedy, was held in Danbury, Connecticut. The event was hosted by the United Way of Western Connecticut and Western Connecticut State University. Frank J. Zenere, school psychologist and crisis team member in the Division of Student Services of the…

  6. Groundwater chemistry of Al under Dutch sandy soils: Effects of land use and depth

    NARCIS (Netherlands)

    Fest, E.P.M.J.; Temminghoff, E.J.M.; Griffioen, J.; Grift, B. van der; Riemsdijk, W.H. van


    Aluminium has received great attention in the second half of the 20th century, mainly in the context of the acid rain problem mostly in forest soils. In this research the effect of land use and depth of the groundwater on Al, pH and DOC concentration in groundwater under Dutch sandy soils has been

  7. 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.


    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

  8. Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil

    International Nuclear Information System (INIS)

    Chen, G.C.; He, Z.L.; Stoffella, P.J.; Yang, X.E.; Yu, S.; Calvert, D.


    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 1183 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. - Fertilizers developed from dolomite phosphate rock (DPR) reduce phosphorus leaching from sandy soil

  9. 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.


    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

  10. Carbon and nitrogen flows through the benthic food web of a photic subtidal sandy sediment

    NARCIS (Netherlands)

    Evrard, V.P.E.; Soetaert, K.E.R.; Heip, C.H.R.; Huettel, M.; Xenopoulos, M.A.; Middelburg, J.J.


    Carbon and nitrogen flows within the food web of a subtidal sandy sediment were studied using stable isotope natural abundances and tracer addition. Natural abundances of 13C and 15N stable isotopes of the consumers and their potential benthic and pelagic resources were measured. δ13C data revealed

  11. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken


    The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...

  12. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas (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 ...

  13. The Sandy Hook Elementary School shooting as tipping point: "This Time Is Different". (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M


    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States.

  14. Lessons from Hurricane Sandy: a community response in Brooklyn, New York. (United States)

    Schmeltz, Michael T; González, Sonia K; Fuentes, Liza; Kwan, Amy; Ortega-Williams, Anna; Cowan, Lisa Pilar


    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.

  15. Development and Application of Syndromic Surveillance for Severe Weather Events Following Hurricane Sandy. (United States)

    Tsai, Stella; Hamby, Teresa; Chu, Alvin; Gleason, Jessie A; Goodrow, Gabrielle M; Gu, Hui; Lifshitz, Edward; Fagliano, Jerald A


    Following Hurricane Superstorm Sandy, the New Jersey Department of Health (NJDOH) developed indicators to enhance syndromic surveillance for extreme weather events in EpiCenter, an online system that collects and analyzes real-time chief complaint emergency department (ED) data and classifies each visit by indicator or syndrome. These severe weather indicators were finalized by using 2 steps: (1) key word inclusion by review of chief complaints from cases where diagnostic codes met selection criteria and (2) key word exclusion by evaluating cases with key words of interest that lacked selected diagnostic codes. Graphs compared 1-month, 3-month, and 1-year periods of 8 Hurricane Sandy-related severe weather event indicators against the same period in the following year. Spikes in overall ED visits were observed immediately after the hurricane for carbon monoxide (CO) poisoning, the 3 disrupted outpatient medical care indicators, asthma, and methadone-related substance use. Zip code level scan statistics indicated clusters of CO poisoning and increased medicine refill needs during the 2 weeks after Hurricane Sandy. CO poisoning clusters were identified in areas with power outages of 4 days or longer. This endeavor gave the NJDOH a clearer picture of the effects of Hurricane Sandy and yielded valuable state preparation information to monitor the effects of future severe weather events. (Disaster Med Public Health Preparedness. 2016;10:463-471).

  16. Weathering the Superstorm: From Texts to Twitter--How Campus Communicators Overcame Hurricane Sandy (United States)

    Towns, Gail


    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…

  17. Vegetation impact on the hydrology of an aeolian sandy soil in a continental climate

    Czech Academy of Sciences Publication Activity Database

    Lichner, Ľ.; Hallett, P. D.; Orfánus, T.; Czachor, H.; Rajkai, K.; Šír, Miloslav; Tesař, Miroslav


    Roč. 3, č. 4 (2010), s. 413-420 ISSN 1936-0584 R&D Projects: GA MŠk MEB0808114 Institutional research plan: CEZ:AV0Z20600510 Keywords : sandy soil * water repellency * plant cover * sorptivity * hydraulic conductivity Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.835, year: 2010

  18. 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.


    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


    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...

  20. 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.


    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

  1. 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


    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...

  2. Enhancing the biodegradation of oil in sandy sediments with choline: A naturally methylated nitrogen compound

    International Nuclear Information System (INIS)

    Mortazavi, Behzad; Horel, Agota; Anders, Jennifer S.; Mirjafari, Arsalan; Beazley, Melanie J.; Sobecky, Patricia A.


    We investigated how additions of choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments contaminated with moderately weathered crude oil (4000 mg kg −1 sediment). Addition of lauroylcholine chloride (LCC) and tricholine citrate (TCC) to oil contaminated sediments resulted in 1.6 times higher hydrocarbon degradation rates compared to treatments without added choline derivatives. However, the degradation rate constant for the oil contaminated sediments amended with LCC was similar to that in contaminated sediments amended with inorganic nitrogen, phosphorus, and glucose. Additions of LLC and TCC to sediments containing extensively weathered oil also resulted in enhanced mineralization rates. Cultivation-free 16S rRNA analysis revealed the presence of an extant microbial community with clones closely related to known hydrocarbon degraders from the Gammaproteobacteria, Alphaproteobacteria, and Firmicutes phyla. The results demonstrate that the addition of minimal amounts of organic compounds to oil contaminated sediments enhances the degradation of hydrocarbons. -- Highlights: •Aerobic degradation of weathered crude oil in sandy sediments was determined. •The effect of input of choline on degradation rates was determined. •16S rRNA clone library analyses were used to examine the microbial phylogeny. •The bacterial community was consisted of clones related to hydrocarbon degraders. •Hydrocarbon degradation in sandy sediments was accelerated by addition of choline. -- Choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments by an extant microbial community

  3. Patterns of Arbuscular Mycorrhizal Fungal Distribution on Mainland and Island Sandy Coastal Plain Ecosystems in Brazil. (United States)

    da Silva, Iolanda Ramalho; de Souza, Francisco Adriano; da Silva, Danielle Karla Alves; Oehl, Fritz; Maia, Leonor Costa


    Although sandy coastal plains are important buffer zones to protect the coast line and maintain biological diversity and ecosystem services, these ecosystems have been endangered by anthropogenic activities. Thus, information on coastal biodiversity and forces shaping coastal biological diversity are extremely important for effective conservation strategies. In this study, we aimed to compare arbuscular mycorrhizal (AM) fungal communities from soil samples collected on the mainland and nearby islands located in Brazilian sandy coastal plain ecosystems (Restingas) to get information about AM fungal biogeography and identify factors shaping these communities. Soil samples were collected in 2013 and 2014 on the beachfront of the tropical sandy coastal plain at six sites (three island and three mainland locations) across the northeast, southeast, and south regions of Brazil. Overall, we recorded 53 AM fungal species from field and trap culture samples. The richness and diversity of AM fungal species did not differ between mainland and island locations, but AM fungal community assemblages were different between mainland and island environments and among most sites sampled. Glomeromycota communities registered from island samples showed higher heterogeneity than communities from mainland samples. Sandy coastal plains harbor diverse AM fungal communities structured by climatic, edaphic, and spatial factors, while the distance from the colonizing source (mainland environments) does not strongly affect the AM fungal communities in Brazilian coastal environments.

  4. Risk assessment and management of an oil contaminated aquifer

    International Nuclear Information System (INIS)

    Braxein, A.; Daniels, H.; Rouve, G.; Rubin, H.


    This paper concerns the provision of the basic information needed for the decision making process regarding the remedial measures leading to reutilization of an oil contaminated aquifer. The study refers to the case history of jet fuel contamination of an aquifer comprising part of the coastal aquifer of Israel. Due to that contamination two major water supply wells were abandoned. This study examines the use of numerical simulations in order to restore the contamination history of the aquifer. Such simulations also provide quantitative information needed for the decision making process regarding the future management of the contaminated aquifer

  5. Remediation of a contaminated thin aquifer by horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Breh, W.; Suttheimer, J.; Hoetzl, H. [Univ. of Karlsruhe (Germany); Frank, K. [GEO-Service GmbH, Rheinmuenster (Germany)


    At an industrial site in Bruchsal (Germany) a huge trichloroethene contamination was found. After common remedial actions proved to be widely ineffective, new investigations led to a highly contaminated thin aquifer above the main aquifer. The investigation and the beginning of the remediation of the thin aquifer by two horizontal wells is described in this paper. Special attention was given to the dependence between precipitation and the flow direction in the thin aquifer and to hydraulic connections between the thin and the main aquifer. Also a short introduction into a new remedial technique by horizontal wells and first results of the test phase of the horizontal wells are given.

  6. Groundwater sustainability assessment in coastal aquifers

    Indian Academy of Sciences (India)

    The present work investigates the response of shallow, coastal unconfined aquifers to anticipated overdraft conditions and climate change effect using numerical simulation. The groundwater flow model MODFLOW and variable density groundwater model SEAWAT are used for this investigation. The transmissivity and ...

  7. Biogeochemical aspects of aquifer thermal energy storage

    NARCIS (Netherlands)

    Brons, H.J.


    During the process of aquifer thermal energy storage the in situ temperature of the groundwater- sediment system may fluctuate significantly. As a result the groundwater characteristics can be considerably affected by a variety of chemical, biogeochemical and microbiological

  8. Hydrochemical characterization of groundwater aquifer using ...

    African Journals Online (AJOL)

    Hydrochemical data analysis revealed four sources of solutes. The processes responsible for their enrichment include: chemical weathering, leaching of the overlying sediments, domestic activities, climatic condition and the flow pattern of the aquifer. The factors have contributed to the changes of the groundwater chemistry ...

  9. Transient well flow in vertically heterogeneous aquifers.

    NARCIS (Netherlands)

    Hemker, C.J.


    A solution for the general problem of computing well flow in vertically heterogeneous aquifers is found by an integration of both analytical and numerical techniques. The radial component of flow is treated analytically; the drawdown is a continuous function of the distance to the well. The

  10. Aquifer restoration: state of the art

    National Research Council Canada - National Science Library

    Knox, Robert C; Knox, R. C


    ... of chemicals or waste materials, improper underground injection of liquid wastes, and placement of septic tank systems in hydrologically and geologically unsuitable locations. Incidents of aquifer pollution from man's waste disposal activities have been discovered with increasing regularity. At the same time, demands for groundwater usage have been inc...

  11. Sedimentological analysis of a contaminated groundwater aquifer

    International Nuclear Information System (INIS)

    Towse, D.


    The use of sedimentological reservoir analysis techniques adapted from standard oilfield practice can improve the efficiency and reduce the costs of the evaluation of groundwater aquifers and the design of restoration programs. An evaluation/restoration program at a site in California drilled over 200 test wells in about 750 ac. All wells were logged lithologically and with wireline. The shallow aquifer is a complex braided alluvial floodplain deposit of Late Quaternary age. Analysis demonstrates depositional and erosional responses to periodic hinterland uplifts and to changing climatic conditions. Channel, overbank, lacustrine, and minor deltaic deposits can be recognized. The aquifer architecture has been interpreted to explain the movement of fuel and halogenated hydrocarbon solvents in the sediments and water. Routine engineering geology techniques and hydrologic tests were used to evaluate contamination and to design experimental restoration processes. As demonstrated here, sedimentological techniques show promise in reducing the costs and time required for this type of study. The abundant detailed data will be used in an attempt to develop a microcomputer-based expert system for rapid preliminary analyses of similar aquifers or reservoirs


    Directory of Open Access Journals (Sweden)

    Yameli Aguilar


    Full Text Available Karstic systems occupy nearly 20% of the surface of the earth and are inhabited by numerous human communities. Karstic aquifers are the most exposed to pollution from human activities. Pollution of karstic aquifers is a severe environmental problem worldwide.  In order to face the vulnerability of karstic aquifers to pollution, researchers have created a diversity of study approaches and models, each one having their own strengths and weaknesses depending on the discipline from which they were originated, thus requiring a thorough discussion within the required multidisciplinary character. The objective of this article was to analyze the theoretical and methodological approaches applied to the pollution of karstic aquifers. The European hydrogeological, land evaluation, hydropedological and a geographic approach were analyzed. The relevance of a geomorphological analysis as a cartographic basis for the analysis of vulnerability and risks were emphasized. From the analysis of models, approaches and methodologies discussed the following recommendation is made: to form an interdisciplinary work team, to elaborate a conceptual model according to the site and the working scale and to e, apply and validate the model.

  13. isotopic characteristics of aquifers in sinai

    International Nuclear Information System (INIS)

    Al-Gamal, S.A.


    the environmental isotopes data (expressed as δ 2 d and δ 18 O) of different aquifers in sinai were treated using correlation and regression techniques. whereas, rain water isotopic data were treated using empirical orthogonal functions (EOF) techniques. environmental isotopes for different aquifers expressed in terms of O-18 and H-2, were taken to represent the isotopic characteristics. regression equations using the highly correlated variables of δ 2 d and δ 18 O were constructed for each aquifer. the latitudinal variations (of rainwater in sinai and selected climatic stations east mediterranean ) versus rainwater isotopic compositions were analyzed using the normalized variables. it was found that the latitudinal variations of the rainwater isotopic compositions ( δ 2 D, δ 18 O), vapor pressure, and surface temperature occurred in parallel and decreased with latitude. in the east mediterranean, empirical linear relationship between altitude and δ 2 D has indicted that the rate of change of δ 2 D with height is comparable with the dry lapse rate in the atmosphere.The obtained regression equations of environmental isotopes data have impacted on different slopes and different constants expressing the non-homogeneity in the isotopic composition of rainwater recharging the aquifers of sinai , due to the presence of different air masses

  14. Quantification of the impacts of coalmine water irrigation on the underlying aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, D.; Usher, B.; van Tonder, G. [University of Free State, Bloemfontein (South Africa). Institute of Groundwater Studies


    It is predicted that vast volumes of affected mine water will be produced by mining activities in the Mpumalanga coalfields of South Africa, The potential environmental impact of this excess water is of great concern in a water-scarce country like South Africa. Research over a period of more than 10 years has shown that this water can be used successfully for the irrigation of a range of crops. There is, however, continuing concern from the local regulators regarding the long-term impact that large-scale mine water irrigation may have on groundwater quality and quantity. Detailed research has been undertaken over the last three years to supplement the groundwater monitoring programme at five different pilot sites, on both virgin soils (greenfields) and in coalmining spoils. These sites range from sandy soils to very clayey soils. The research has included soil moisture measurements, collection of in situ soil moisture over time, long-term laboratory studies of the leaching and attenuation properties of different soils and the impact of irrigation on acid rock drainage processes, and in depth determination of the hydraulic properties of the subsurface at each of these sites, including falling head tests, pumping tests and point dilution tests. This has been supported by geochemical modelling of these processes to quantify the impacts. The results indicate that many of the soils have considerable attenuation capacities and that in the period of irrigation, a large proportion of the salts have been contained in the upper portions of the unsaturated zones below each irrigation pivot. The volumes and quality of water leaching through to the aquifers have been quantified at each site. From this mixing ratios have been calculated in order to determine the effect of the irrigation water on the underlying aquifers.

  15. Tidal Pumping-Induced Nutrients Dynamics and Biogeochemical Implications in an Intertidal Aquifer (United States)

    Liu, Yi; Jiao, Jiu Jimmy; Liang, Wenzhao; Luo, Xin


    Tidal pumping is a major driving force affecting water exchange between land and sea, biogeochemical reactions in the intertidal aquifer, and nutrient loading to the sea. At a sandy beach of Tolo Harbour, Hong Kong, the nutrient (NH4+, NO2-, NO3-, and PO43-) dynamic in coastal groundwater mixing zone (CGMZ) is found to be fluctuated with tidal oscillation. Nutrient dynamic is mainly controlled by tidal pumping-induced organic matter that serves as a reagent of remineralization in the aquifer. NH4+, NO2-, and PO43- are positively correlated with salinity. Both NH4+ and PO43- have negative correlations with oxidation/reduction potential. NH4+ is the major dissolved inorganic nitrogen species in CGMZ. The adsorption of PO43- onto iron oxides occurs at the deep transition zone with a salinity of 5-10 practical salinity unit (psu), and intensive N-loss occurs in near-surface area with a salinity of 10-25 psu. The biogeochemical reactions, producing PO43- and consuming NH4+, are synergistic effect of remineralization-nitrification-denitrification. In CGMZ, the annual NH4+ loss is estimated to be 4.32 × 105 mol, while the minimum annual PO43- production is estimated to be 2.55 × 104 mol. Applying these rates to the entire Tolo Harbour, the annual NH4+ input to the harbor through the remineralization of organic matters is estimated to be 1.02 × 107 mol. The annual NH4+ loss via nitrification is 1.32 × 107 mol, and the annual PO43- production is 7.76 × 105 mol.

  16. Application of Fe-Cu/Biochar System for Chlorobenzene Remediation of Groundwater in Inhomogeneous Aquifers

    Directory of Open Access Journals (Sweden)

    Xu Zhang


    Full Text Available Chlorobenzene (CB, as a typical Volatile Organic Contaminants (VOC, is toxic, highly persistent and easily migrates in water, posing a significant risk to human health and subsurface ecosystems. Therefore, exploring effective approaches to remediate groundwater contaminated by CB is essential. As an enhanced micro-electrolysis system for CB-contaminated groundwater remediation, this study attempted to couple the iron-copper bimetal with biochar. Two series of columns using sands with different grain diameters were used, consisting of iron, copper and biochar fillings as the permeable reactive barriers (PRBs, to simulate the remediation of CB-contaminated groundwater in homogeneous and heterogeneous aquifers. Regardless of the presence of homogeneous or heterogeneous porous media, the CB concentrations in the effluent from the PRB columns were significantly lower than the natural sandy columns, suggesting that the iron and copper powders coupled with biochar particles could have a significant removal effect compared to the natural sand porous media in the first columns. CB was transported relatively quickly in the heterogeneous porous media, likely due to the fact that the contaminant residence time is proportional to the infiltration velocities in the different types of porous media. The average effluent CB concentrations from the heterogeneous porous media were lower than those from homogeneous porous media. The heterogeneity retarded the vertical infiltration of CB, leading to its extended lateral distribution. During the treatment process, benzene and phenol were observed as the products of CB degradation. The ultimate CB removal efficiency was 61.4% and 68.1%, demonstrating that the simulated PRB system with the mixture of iron, copper and biochar was effective at removing CB from homogeneous and heterogeneous aquifers.

  17. Hydrogeochemical processes affecting the migration of radionuclides in a fluvial sand aquifer at the Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Jackson, R.E.; Inch, K.J.


    In the mid-1950's two experimental disposals of liquid radioactive waste containing about 700 curries of strontium-90 and cesium-137 were made into pits in sandy ground at one of the disposal areas at Chalk River Nuclear Laboratories. Since then, the wastes have migrated into two nearby aquifers and have chromatographically separated into strontium-90 and cesium-137 plumes moving at velocities less than that of the transporting groundwater. Analysis of radioactively contaminated aquifer sediments showed that most of the strontium-90 is exchangeably adsorbed, primarily to feldspars and layer silicates (mainly biotite); the rest is either specifically adsorbed to iron (III) and perhaps manganese (IV) oxhydroxides or fixed to unknown sinks. Less than one half of adsorbed cesium-137 is exchangeable with 0.5 m calcium chloride; the high levels of cesium-137 adsorption and fixation are probably due to its reaction with micaceous minerals. Complexation of strontium-90 and cesium-137 does not appear to be an important factor affecting their transport or adsorption. In studies of groundwater quality or pollution, dissolved oxygen and sulfide should be measured in addition to the redox potential since it allows independent assessment of the redox levels. The latter were found to affect the mobility of multivalent transition metals and nonmetals. (DN)

  18. Hydrogeology - AQUIFER_SYSTEMS_BEDROCK_IDNR_IN: Bedrock Aquifer Systems of Indiana (Indiana Department of Natural Resources, 1:500,000, Polygon Shapefile) (United States)

    NSGIC State | GIS Inventory — AQUIFER_SYSTEMS_BEDROCK_IDNR_IN is a polygon shapefile that shows bedrock aquifer systems of the State of Indiana. The source scale of the map depicting the aquifers...

  19. Arsenic release during managed aquifer recharge (MAR) (United States)

    Pichler, T.; Lazareva, O.; Druschel, G.


    The mobilization and addition of geogenic trace metals to groundwater is typically caused by anthropogenic perturbations of the physicochemical conditions in the aquifer. This can add dangerously high levels of toxins to groundwater, thus compromising its use as a source of drinking water. In several regions world-wide, aquifer storage and recovery (ASR), a form of managed aquifer recharge (MAR), faces the problem of arsenic release due to the injection of oxygenated storage water. To better understand this process we coupled geochemical reactive transport modeling to bench-scale leaching experiments to investigate and verify the mobilization of geogenic arsenic (As) under a range of redox conditions from an arsenic-rich pyrite bearing limestone aquifer in Central Florida. Modeling and experimental observations showed similar results and confirmed the following: (1) native groundwater and aquifer matrix, including pyrite, were in chemical equilibrium, thus preventing the release of As due to pyrite dissolution under ambient conditions; (2) mixing of oxygen-rich surface water with oxygen-depleted native groundwater changed the redox conditions and promoted the dissolution of pyrite, and (3) the behavior of As along a flow path was controlled by a complex series of interconnected reactions. This included the oxidative dissolution of pyrite and simultaneous sorption of As onto neo-formed hydrous ferric oxides (HFO), followed by the reductive dissolution of HFO and secondary release of adsorbed As under reducing conditions. Arsenic contamination of drinking water in these systems is thus controlled by the re-equilibration of the system to more reducing conditions rather than a purely oxidative process.


    Directory of Open Access Journals (Sweden)

    Anica Durau


    Full Text Available Technological factors with major implications in obtaining high yields and quality in peaches grown on sandy soils are planting row distance and shape of the crown, soil maintenance system, chemical, organic and foliar fertilzation. A smal size combined with the flatening of the crowns of the tres alows a dense planting, also ensure proper mechanization of work and easy penetration of light to the leaves and fruits. Crown form vertical belt proved to be suitable for al planting distances studied, easily made and maintained, having fruit production ranged betwen 15.9 t / ha at a distance of 2 m, 10.3 t / ha at a distance of 2.5 m and 7.9 t / ha at a distance of 3 m. The state of soil nutrient supply influence sucesful peach crop on sandy soils. The fertilzer dose of technology to N10 P80 K10 kg s.a / ha production was 34.9 t / ha. Organic fertilzation also contributes to obtaining high yields of peach. In sandy soil conditions most fruit production of 9.6 t / ha was obtained by fertilzation with organic manure 60t/ha. Besides fertilzation, soil maintenance system is one important link in the technology peach crop on sandy soils. The results found that the biggest peach fruit production was obtained from field maintenance system black-8,2t/ha. Using technology in foliar peaches culture on sandy soils, is an important means of providing nutrients that lead to improved proceses of growth and fructification. The best way is with foliar fertilzation Folibor in dose 5l/ha, the production obtained was 12.4 t /ha.

  1. Telehealth at the US Department of Veterans Affairs after Hurricane Sandy. (United States)

    Der-Martirosian, Claudia; Griffin, Anne R; Chu, Karen; Dobalian, Aram


    Background Like other integrated health systems, the US Department of Veterans Affairs has widely implemented telehealth during the past decade to improve access to care for its patient population. During major crises, the US Department of Veterans Affairs has the potential to transition healthcare delivery from traditional care to telecare. This paper identifies the types of Veterans Affairs telehealth services used during Hurricane Sandy (2012), and examines the patient characteristics of those users. Methods This study conducted both quantitative and qualitative analyses. Veterans Affairs administrative and clinical data files were used to illustrate the use of telehealth services 12 months pre- and 12 months post- Hurricane Sandy. In-person interviews with 31 key informants at the Manhattan Veterans Affairs Medical Center three-months post- Hurricane Sandy were used to identify major themes related to telecare. Results During the seven-month period of hospital closure at the Manhattan Veterans Affairs Medical Center after Hurricane Sandy, in-person patient visits decreased dramatically while telehealth visits increased substantially, suggesting that telecare was used in lieu of in-person care for some vulnerable patients. The most commonly used types of Veterans Affairs telehealth services included primary care, triage, mental health, home health, and ancillary services. Using qualitative analyses, three themes emerged from the interviews regarding the use of Veterans Affairs telecare post- Hurricane Sandy: patient safety, provision of telecare, and patient outreach. Conclusion Telehealth offers the potential to improve post-disaster access to and coordination of care. More information is needed to better understand how telehealth can change the processes and outcomes during disasters. Future studies should also evaluate key elements, such as adequate resources, regulatory and technology issues, workflow integration, provider resistance, diagnostic fidelity and

  2. Mineralogical and Micro-fabric investigation of the Sandy Facies of Opalinus Clay (Mont Terri)

    International Nuclear Information System (INIS)

    Kaufhold, Annette; Siegesmund, Siegfried; Dohrmann, Reiner; Graesle, Werner; Plischke, Ingo


    In the field of geological disposal of radioactive waste in many countries argillaceous formations are considered as potential host rock. For the understanding of the long-term behaviour of clay host rock, it is important to understand the interaction between mechanical behaviour, micro-fabric, and mineral composition. Previous publications showed that particularly the carbonate content and the arrangement of the carbonate grains (as cement in the matrix or as shells) determines the mechanical strength of Opalinus Clay and Callovo-Oxfordian Clay specimens, respectively. Klinkenberg et al. (2009) studied the shaly facies of Opalinus Clay, however, the actual deposit is planned to be built in the sandy facies of Opalinus Clay. The aim of the present study is to investigate the relation between micro-fabric, mineral composition, and mechanical properties of different samples derived from the sandy facies (BLT-A2). Image analysis showed that the carbonates in the sandy facies mainly occur as 1) matrix which in turn acts as cement. Carbonates also occur 2) in the fine sand fraction and 3) biogenic carbonates as traces. The carbonates of the sandy facies, therefore, appear to be similar to the carbonates of the Callovo-Oxfordian Clay with respect to their possible influence on failure strength. The mechanical testing showed that the shear strength increases with increasing carbonate content. This phenomenon was also observed for the samples of the Callovo-Oxfordian Clay, while the opposite relation was found for the shaly facies of the Opalinus Clay. Preliminary results presented here, indicate that the sandy facies (drilling BLT-A2) and Callovo-Oxfordian Clay show similar mechanical properties - in detail: 1) Micro-fabric: carbonates predominate in the matrix, 2) Mineralogy: high carbonate content and 3) Mechanical testing: shear strength increases with increasing carbonate content, where the type of carbonates which controls the increase of strength has to be

  3. Impact of pH on hydrogen oxidizing redox processes in aquifers due to gas intrusions (United States)

    Metzgen, Adrian; Berta, Marton; Dethlefsen, Frank; Ebert, Markus; Dahmke, Andreas


    Hydrogen production from excess energy and its storage can help increasing the efficiency of solar and wind in the energy mix. Therefore, hydrogen needs large-scale intermediate storage independent of the intended later use as hydrogen gas or as reactant to produce methane in the Sabatier process. A possible storage solution is using the geological subsurface such as caverns built in salt deposits or aquifers that are not used for drinking water production. However, underground storage of hydrogen gas potentially leads to accidental gas leakages into near-surface potable aquifers triggering subsequent geochemical processes. These leakages pose potential risks that are currently not sufficiently understood. To close this gap in knowledge, a high-pressure laboratory column system was used to simulate a hydrogen gas intrusion into a shallow aquifer. Water and sediment were gained from a sandy Pleistocene aquifer near Neumünster, Germany. In the first stage of the experiment, 100% hydrogen gas was used to simulate dissolved hydrogen concentrations between 800 and 4000 µM by varying pH2 between 2 and 15 bars. pH values rose to between 7.9 and 10.4, partly due to stripping CO2 from the groundwater used during H2 gas addition. In a second stage, the pH was regulated in a range of 6.7 to 7.9 by using a gas mixture of 99% H2 and 1% CO2 at 5 bars of total gas pressure. Observed processes included hydrogen oxidation, sulfate reduction, acetogenesis, formate production, and methanogenesis, which were independent of the hydrogen concentration. Hydrogen oxidation and sulfate reduction showed zeroth order reaction rates and rate constants (106 to 412 µM/h and 12 to 33 µM/h, respectively) in the pH range between 8 and 10. At pH levels between 7 and 8, both reactions started out faster near the column's inflow but then seemed limited towards the columns outflow, suggesting the dependence of sulfate reduction on the pH-value. Acetogenesis dominated the pH range between 8 and 10

  4. Simulation of the transfer of hydrocarbons in unconfined aquifer in tropical zone: the case of benzene (United States)

    Agnès Kouamé, Amenan; Jaboyedoff, Michel; Derron, Marc-Henri; Kouamé, Kan Jean


    Groundwater is the largest global reserves of continental freshwater (Bosca, 2002) and also an important source of drinking water in many parts of the world (Brassington. 2007). However, this resource is today threatened by pollution such as inadequate supply of drinking water services, inaccessibility and / or dilapidated sanitation facilities and excessive use fertilizers, and industrial wastewater and solid waste pesticides (Boubacar, 2010) and the rapid urbanization in great cities (Foster, 2001). Abidjan, the largest city in Côte d'Ivoire is also facing pollution problems such as illegal dumping of waste, waste oil spilled garages, land application of domestic and industrial wastewater, automotive workshops, overexploitation of sand in the Ebrié lagoon, open waste dump of Akouédo and the spill of about 400,000 liters of toxic waste from the ship "Probo Koala" in August 2006. The Abidjan aquifer or the Continental terminal aquifer is the main source of supply drinking water. It is mainly composed of sandy and it is an unconfined aquifer as a whole (Jourda, 1987). According to Gilli and al., (2012), the recharge of unconfined aquifers comes mostly from the infiltration of surface water including rainwater. These waters on their transport in the basement could carry certain pollutants into groundwater. Kouamé (2007) reports a potential groundwater pollution of the "Continental terminal" aquifer in Abidjan. In addition to the cases cited pollution, there has been a proliferation of service stations in the district of Abidjan and this can cause possible pollution. We deemed it necessary to conduct a study on the groundwater pollution of Abidjan by oil in general. We chose benzene to simulate organic pollution in case of accident. To observe the likely evolution of such contaminants in the subsurface, we developed hydrogeological models that couple groundwater flow and benzene transport with FEFLOW software in steady and transient states. The models are composed

  5. Monitoring Aquifer Depletion from Space: Case Studies from the Saharan and Arabian Aquifers (United States)

    Ahmed, M.; Sultan, M.; Wahr, J. M.; Yan, E.


    Access to potable fresh water resources is a human right and a basic requirement for economic development in any society. In arid and semi-arid areas, the characterization and understanding of the geologic and hydrologic settings of, and the controlling factors affecting, these resources is gaining increasing importance due to the challenges posed by increasing population. In these areas, there is immense natural fossil fresh water resources stored in large extensive aquifers, the transboundary aquifers. Yet, natural phenomena (e.g., rainfall patterns and climate change) together with human-related factors (e.g., population growth, unsustainable over-exploitation, and pollution) are threatening the sustainability of these resources. In this study, we are developing and applying an integrated cost-effective approach to investigate the nature (i.e., natural and anthropogenic) and the controlling factors affecting the hydrologic settings of the Saharan (i.e., Nubian Sandstone Aquifer System [NSAS], Northwest Sahara Aquifer System [NWSA]) and Arabian (i.e., Arabian Peninsula Aquifer System [APAS]) aquifer systems. Analysis of the Gravity Recovery and Climate Experiment (GRACE)-derived Terrestrial Water Storage (TWS) inter-annual trends over the NSAS and the APAS revealed two areas of significant TWS depletions; the first correlated with the Dakhla Aquifer System (DAS) in the NSAS and second with the Saq Aquifer System (SAS) in the APAS. Annual depletion rates were estimated at 1.3 × 0.66 × 109 m3/yr and 6.95 × 0.68 × 109 m3/yr for DAS and SAS, respectively. Findings include (1) excessive groundwater extraction, not climatic changes, is responsible for the observed TWS depletions ;(2) the DAS could be consumed in 350 years if extraction rates continue to double every 50 years and the APAS available reserves could be consumed within 60-140 years at present extraction (7.08 × 109 m3/yr) and depletion rates; and (3) observed depletions over DAS and SAS and their

  6. San Pedro River Aquifer Binational Report (United States)

    Callegary, James B.; Minjárez Sosa, Ismael; Tapia Villaseñor, Elia María; dos Santos, Placido; Monreal Saavedra, Rogelio; Grijalva Noriega, Franciso Javier; Huth, A. K.; Gray, Floyd; Scott, C. A.; Megdal, Sharon; Oroz Ramos, L. A.; Rangel Medina, Miguel; Leenhouts, James M.


    The United States and Mexico share waters in a number of hydrological basins and aquifers that cross the international boundary. Both countries recognize that, in a region of scarce water resources and expanding populations, a greater scientific understanding of these aquifer systems would be beneficial. In light of this, the Mexican and U.S. Principal Engineers of the International Boundary and Water Commission (IBWC) signed the “Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transboundary Aquifer Assessment Program" on August 19, 2009 (IBWC-CILA, 2009). This IBWC “Joint Report” serves as the framework for U.S.-Mexico coordination and dialogue to implement transboundary aquifer studies. The document clarifies several details about the program such as background, roles, responsibilities, funding, relevance of the international water treaties, and the use of information collected or compiled as part of the program. In the document, it was agreed by the parties involved, which included the IBWC, the Mexican National Water Commission (CONAGUA), the U.S. Geological Survey (USGS), and the Universities of Arizona and Sonora, to study two priority binational aquifers, one in the San Pedro River basin and the other in the Santa Cruz River basin. This report focuses on the Binational San Pedro Basin (BSPB). Reasons for the focus on and interest in this aquifer include the fact that it is shared by the two countries, that the San Pedro River has an elevated ecological value because of the riparian ecosystem that it sustains, and that water resources are needed to sustain the river, existing communities, and continued development. This study describes the aquifer’s characteristics in its binational context; however, most of the scientific work has been undertaken for many years by each country without full knowledge of the conditions on the other side of the border. The general objective of this study is to

  7. The influence of fish ponds and salinization on groundwater quality in the multi-layer coastal aquifer system in Israel (United States)

    Tal, A.; Weinstein, Y.; Yechieli, Y.; Borisover, M.


    This study focuses on the impact of surface reservoirs (fish ponds) on a multi aquifer coastal system, and the relation between the aquifer and the sea. The study was conducted in an Israeli Mediterranean coastal aquifer, which includes a sandy phreatic unit and two confined calcareous sandstone units. The geological description is based on 52 wells, from which 33 samples were collected for stable isotope analysis and 25 samples for organic and inorganic parameters. Hydraulic head and chemical measurements suggest that there is an hydraulic connection between the fish ponds above the aquifer and the phreatic unit, whereas the connection with the confined units is very limited. The phreatic unit is characterized by a low concentration of oxygen and high concentrations of ammonium and phosphate, while the confined units are characterized by higher oxygen and much lower ammonium and phosphate concentrations. Organic matter fluorescence was found to be a tool to distinguish the contribution of the pond waters, whereby a pond water signature (characterized by proteinaceous (tryptophan-like) and typical humic-matter fluorescence) was found in the phreatic aquifer. The phreatic unit is also isotopically enriched, similar to pond waters, with δ18O of -1‰ and δD of -4.6‰, indicating enhanced evaporation of the pond water before infiltration, whereas there is a depleted isotopic composition in the confined units (δ18O = -4.3‰, δD = -20.4‰), which are also OM-poor. The Phreeqc model was used for quantitative calculation of the effect of pond losses on the different units. The Dissolved Inorganic Nitrogen (DIN) in the upper unit increases downstream from the ponds toward the sea, probably due to organic matter degradation, suggesting contribution of DIN from shallow groundwater flow to the sea. 87Sr/86Sr and Mg/Ca in the brackish and saline groundwater of the lower confined units increase toward seawater value, suggesting that the salinization process in the region

  8. Management Proposals of the Sabinas Reynosa Aquifer in Northeast Mexico, and Implications in the Development of Main Towns in Chihuahua (United States)

    Sanchez, E. E.


    The Sabinas Reynosa water table aquifer is located in northeast Mexico in the state of Chihuahua, where this hydrologic unit is controlled by Laramide structures. The hydrostratigraphy consists of three units. At the base is a slightly compacted conglomerate HU1. The middle unit HU2 consists of clay materials packed with a carbonate cement. The upper unit is constituted by a sandy caliche with a calcareous matrix with secondary porosity, which allows it to store and transmit large volumes of water. The three units are of Paleogene age. Recently, the towns near the Sabinas Reynosa aquifer have presented supply problems, thus, this project will determine the hydrologic characterization using the groundwater budget method in order to establish the volume of water that the aquifer will yield per unit of time. The first phase consisted of defining the balance equation, by establishing the terms involved in the budget and calculating their respective values. Two different factors were defined: the inflows and outflows. In the first case, underground inflow with 225.68 Mm3 in the last five years, recharge by irrigation with 32.08 Mm3 and anthropogenic recharge with 270.50 Mm3 were considered. In the second case, the factors include underground outflow with 359.55 Mm3, pumping with 561.43 Mm3 and evapotranspiration from the water table with 130.61 Mm3. Although this last variable was calculated on a preliminary basis, a more accurate estimate requires additional studies (in process), with the aim of obtaining a more representative value. In this work is considered that evapotranspiration takes a decisive role in the analysis of the budget and hence, in the decisions that have to be taken for the proper management of the hydrological system.

  9. Quantifying Modern Recharge and Depletion Rates of the Nubian Aquifer in Egypt (United States)

    Ahmed, Mohamed; Abdelmohsen, Karem


    Egypt is currently seeking additional freshwater resources to support national reclamation projects based mainly on the Nubian aquifer groundwater resources. In this study, temporal (April 2002 to June 2016) Gravity Recovery and Climate Experiment (GRACE)-derived terrestrial water storage (TWSGRACE) along with other relevant datasets was used to monitor and quantify modern recharge and depletion rates of the Nubian aquifer in Egypt (NAE) and investigate the interaction of the NAE with artificial lakes. Results indicate: (1) the NAE is receiving a total recharge of 20.27 ± 1.95 km3 during 4/2002-2/2006 and 4/2008-6/2016 periods, (2) recharge events occur only under excessive precipitation conditions over the Nubian recharge domains and/or under a significant rise in Lake Nasser levels, (3) the NAE is witnessing a groundwater depletion of - 13.45 ± 0.82 km3/year during 3/2006-3/2008 period, (4) the observed groundwater depletion is largely related to exceptional drought conditions and/or normal baseflow recession, and (5) a conjunctive surface water and groundwater management plan needs to be adapted to develop sustainable water resources management in the NAE. Findings demonstrate the use of global monthly TWSGRACE solutions as a practical, informative, and cost-effective approach for monitoring aquifer systems across the globe.

  10. Evaluation of conceptual and numerical models for arsenic mobilization and attenuation during managed aquifer recharge. (United States)

    Wallis, Ilka; Prommer, Henning; Simmons, Craig T; Post, Vincent; Stuyfzand, Pieter J


    Managed Aquifer Recharge (MAR) is promoted as an attractive technique to meet growing water demands. An impediment to MAR applications, where oxygenated water is recharged into anoxic aquifers, is the potential mobilization of trace metals (e.g., arsenic). While conceptual models for arsenic transport under such circumstances exist, they are generally not rigorously evaluated through numerical modeling, especially at field-scale. In this work, geochemical data from an injection experiment in The Netherlands, where the introduction of oxygenated water into an anoxic aquifer mobilized arsenic, was used to develop and evaluate conceptual and numerical models of arsenic release and attenuation under field-scale conditions. Initially, a groundwater flow and nonreactive transport model was developed. Subsequent reactive transport simulations focused on the description of the temporal and spatial evolution of the redox zonation. The calibrated model was then used to study and quantify the transport of arsenic. In the model that best reproduced field observations, the fate of arsenic was simulated by (i) release via codissolution of arsenopyrite, stoichiometrically linked to pyrite oxidation, (ii) kinetically controlled oxidation of dissolved As(III) to As(V), and (iii) As adsorption via surface complexation on neo-precipitated iron oxides.

  11. Vertical gradients in water chemistry and age in the Northern High Plains Aquifer, Nebraska, 2003 (United States)

    McMahon, P.B.; Böhlke, J.K.; Carney, C.P.


    The northern High Plains aquifer is the primary source of water used for domestic, industrial, and irrigation purposes in parts of Colorado, Kansas, Nebraska, South Dakota, and Wyoming. Despite the aquifer’s importance to the regional economy, fundamental ground-water characteristics, such as vertical gradients in water chemistry and age, remain poorly defined. As part of the U.S. Geological Survey’s National Water-Quality Assessment Program, water samples from nested, short-screen monitoring wells installed in the northern High Plains aquifer were analyzed for major ions, nutrients, trace elements, dissolved organic carbon, pesticides, stable and radioactive isotopes, dissolved gases, and other parameters to evaluate vertical gradients in water chemistry and age in the aquifer. Chemical data and tritium and radiocarbon ages show that water in the aquifer was chemically and temporally stratified in the study area, with a relatively thin zone of recently recharged water (less than 50 years) near the water table overlying a thicker zone of older water (1,800 to 15,600 radiocarbon years). In areas where irrigated agriculture was an important land use, the recently recharged ground water was characterized by elevated concentrations of major ions and nitrate and the detection of pesticide compounds. Below the zone of agricultural influence, major-ion concentrations exhibited small increases with depth and distance along flow paths because of rock/water interactions. The concentration increases were accounted for primarily by dissolved calcium, sodium, bicarbonate, sulfate, and silica. In general, the chemistry of ground water throughout the aquifer was of high quality. None of the approximately 90 chemical constituents analyzed in each sample exceeded primary drinking-water standards.Mass-balance models indicate that changes in groundwater chemistry along flow paths in the aquifer can be accounted for by small amounts of feldspar and calcite dissolution; goethite

  12. Field pilot test of surfactant-enhanced remediation of trichloroethane DNAPL in a sand aquifer

    International Nuclear Information System (INIS)

    Jackson, R.E.; Butler, G.W.; Londergan, J.T.; Mariner, P.E.; Pickens, J.F.; Fountain, J.C.


    The sequence of lacustrine and outwash deposits beneath a vapor degreasing operation at the Paducah Gaseous Division Plant, Kentucky, is contaminated with trichloroethane due to leakage from a sewer/sump line. A plume of dissolved trichloroethane (TCE) extends throughout an area of approximately 3 km 2 in the Regional Gravel Aquifer (RGA) which is located between 20 and 30 meters below ground surface. It is suspected that some 40,000 liters of TCE might have escaped into the subsurface at Paducah, most of which is still present in the lacustrine deposits and the underlying RGA as DNAPL. A field test to confirm the presence of TCE DNAPL in the sandy, upper portion of the RGA around a monitoring well and to test the efficiency of the surfactant for TCE solubilization is described. The aqueous concentrations of TCE in this well have consistently been measured at 300--550 mg TCE/L over a period of three years. The use of Capillary and Bond numbers to estimate the improbability of mobilization of DNAPL due to the lowering of the interfacial tension is described. The multiphase, multicomponent simulator UTCHEM was used to simulate both the injection and extraction of the surfactant solution and the solubilization of the TCE by the surfactant micelles

  13. Factors affecting the distribution of hydrocarbon contaminants and hydrogeochemical parameters in a shallow sand aquifer (United States)

    Lee, Jin-Yong; Cheon, Jeong-Yong; Lee, Kang-Kun; Lee, Seok-Young; Lee, Min-Hyo


    The distributions of hydrocarbon contaminants and hydrogeochemical parameters were investigated in a shallow sand aquifer highly contaminated with petroleum hydrocarbons leaked from solvent storage tanks. For these purposes, a variety of field investigations and studies were performed, which included installation of over 100 groundwater monitoring wells and piezometers at various depths, soil logging and analyses during well and piezometer installation, chemical analysis of groundwater, pump tests, and slug tests. Continuous water level monitoring at three selected wells using automatic data-logger and manual measuring at other wells were also conducted. Based on analyses of the various investigations and tests, a number of factors were identified to explain the distribution of the hydrocarbon contaminants and hydrogeochemical parameters. These factors include indigenous biodegradation, hydrostratigraphy, preliminary pump-and-treat remedy, recharge by rainfall, and subsequent water level fluctuation. The permeable sandy layer, in which the mean water table elevation is maintained, provided a dominant pathway for contaminant transport. The preliminary pump-and-treat action accelerated the movement of the hydrocarbon contaminants and affected the redox evolution pattern. Seasonal recharge by rain, together with indigenous biodegradation, played an important role in the natural attenuation of the petroleum hydrocarbons via mixing/dilution and biodegradation. The water level fluctuations redistributed the hydrocarbon contaminants by partitioning them into the soil and groundwater. The identified factors are not independent but closely inter-correlated.

  14. Intrinsic vulnerability assessment of shallow aquifers of the sedimentary basin of southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Saheed A. Oke


    Full Text Available The shallow groundwater of the multi-layered sedimentary basin aquifer of southwestern Nigeria was assessed based on its intrinsic vulnerability property. The vulnerability evaluation involves determining the protective cover and infiltration condition of the unsaturated zone in the basin. This was achieved using the PI (P stands for protective cover effectiveness of the overlying lithology and I indicates the degree of infiltration bypass vulnerability method of the European vulnerability approach. The PI method specifically measures the protection cover and the degree to which the protective cover is bypassed. Intrinsic parameters assessed were the subsoil, lithology, topsoil, recharge and fracturing for the protective cover. The saturated hydraulic conductivity of topsoil, infiltration processes and the lateral surface and subsurface flow were evaluated for the infiltration bypassed. The results show moderate to very low vulnerability areas. Low vulnerability areas were characterised by lithology with massive sandstone and limestone, subsoils of sandy loam texture, high slopes and high depth to water table. The moderate vulnerability areas were characterised by high rainfall and high recharge, low water table, unconsolidated sandstones and alluvium lithology. The intrinsic vulnerability properties shown in vulnerability maps will be a useful tool in planning and monitoring land use activities that can be of impact in groundwater pollution.

  15. The effect of vadose zone heterogeneities on vapor phase migration and aquifer contamination by volatile organics

    Energy Technology Data Exchange (ETDEWEB)

    Seneviratne, A.; Findikakis, A.N. [Bechtel Corporation, San Francisco, CA (United States)


    Organic vapors migrating through the vadose zone and inter-phase transfer can contribute to the contamination of larger portions of aquifers than estimated by accounting only for dissolved phase transport through the saturated zone. Proper understanding of vapor phase migration pathways is important for the characterization of the extent of both vadose zone and the saturated zone contamination. The multiphase simulation code T2VOC is used to numerically investigate the effect of heterogeneties on the vapor phase migration of chlorobenzene at a hypothetical site where a vapor extraction system is used to remove contaminants. Different stratigraphies consisting of alternate layers of high and low permeability materials with soil properties representative of gravel, sandy silt and clays are evaluated. The effect of the extent and continuity of low permeability zones on vapor migration is evaluated. Numerical simulations are carried out for different soil properties and different boundary conditions. T2VOC simulations with zones of higher permeability were made to assess the role of how such zones in providing enhanced migration pathways for organic vapors. Similarly, the effect of the degree of saturation of the porous medium on vapor migration was for a range of saturation values. Increased saturation reduces the pore volume of the medium available for vapor diffusion. Stratigraphic units with higher aqueous saturation can retard the vapor phase migration significantly.

  16. Plume persistence caused by back diffusion from thin clay layers in a sand aquifer following TCE source-zone hydraulic isolation. (United States)

    Parker, Beth L; Chapman, Steven W; Guilbeault, Martin A


    . While there is no doubt that DNAPL source mass reduction can eventually improve downgradient groundwater quality, the magnitude and time scale over which the improvement occurs is the major uncertainty given current characterization approaches. This study shows that even one thin clay bed, less than 0.2 m thick, can cause plume persistence due to back diffusion for several years or even decades after the flux from the source is completely isolated. Thin clay beds, which have a large storage capacity for dissolved and sorbed contaminant mass, are common in many types of sandy aquifers. However, without careful inspection of continuous cores and sampling, such thin clay beds, and their potential for causing long-term back-diffusion effects, can easily go unnoticed during site characterization.

  17. Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy (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


    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


    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo Freres Stipp


    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

  19. Spatiotemporal Effects of Climate Variability and Urban Growth on the "Valle de Toluca" Aquifer (Mexico) (United States)

    Mastachi-Loza, C. A.; Diaz-Delgado, C.; Esteller, M. V.; Gomez-Albores, M. A.; Becerril, R.; Ruiz-Gomez, M. D.


    Toluca city is located in the "Valle de Toluca" at the upper course of the Lerma river basin, is an important economic center which contributes with 1.2% of Gross National Product (GNP) since it is an industrial city, The city has grown due to the economic development sustained by the "Valle de Toluca" aquifer which provides water for human consumption, industrial facilities and crop irrigation. Recent studies have shown that in the last 50 years the annual precipitation rate in Toluca has increased 122 mm, whereas the daily minimum temperature has increased 1.1 °C and the daily maximum temperature has also increased 0.8 °C. These results show a general overview of the change in the climate conditions of the city; however they do not show the spatial distribution of the change. For this reason, the aim of this work was to evaluate the spatiotemporal change of precipitation rates and urban growth in order to determine their effects over the "Valle de Toluca" aquifer. In order to detect the urban growth, a supervised classification technique has been used taking into account Landsat TM satellite images between 1973, 1986, 2000 and 2005. A yearly spatiotemporal raster set of rainfall rates from 1980 to 2010 were obtained interpolating data from 812 climatologic stations. To evaluate the effect in annual precipitation rates and urban growth over the aquifer, we interpolate data from 38 piezometers from 1980 to 2010 to obtain a spatiotemporal raster set. The piezometric values correspond to the aquifer's upper level. The spatiotemporal raster sets were analyzed with the non-parametric Theil-Sen test to determine trends in piezometric levels and precipitation rates. Finally the urban growth, spatial-temporal trends of precipitation rates and piezometric levels were displayed in a GIS and then subjectively analyzed to figure out coincidences. An increase in annual precipitation rates (+87 mm) over Toluca's Valley during the last three decades was observed specially

  20. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, M., E-mail: [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Opsahl, S.P. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States); Mahler, B.J. [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Herrington, C. [City of Austin Watershed Protection Department, Austin, TX 78704 (United States); Sample, T.L. [U.S. Geological Survey, 19241 David Memorial Dr., Ste. 180, Conroe, TX 77385 (United States); Banta, J.R. [U.S. Geological Survey, 5563 DeZavala, Ste. 290, San Antonio, TX 78249 (United States)


    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO{sub 3}{sup −}) loading to surface and groundwater. We investigate variability and sources of NO{sub 3}{sup −} in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO{sub 3}{sup −} stable isotopes (δ{sup 15}N and δ{sup 18}O). These data were augmented by historical data collected from 1937 to 2007. NO{sub 3}{sup −} concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO{sub 3}{sup −} concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO{sub 3}{sup −} concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO{sub 3}{sup −}. These results highlight the vulnerability of karst aquifers to NO{sub 3}{sup −} contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO{sub 3}{sup −} than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates

  1. Source, variability, and transformation of nitrate in a regional karst aquifer: Edwards aquifer, central Texas

    International Nuclear Information System (INIS)

    Musgrove, M.; Opsahl, S.P.; Mahler, B.J.; Herrington, C.; Sample, T.L.; Banta, J.R.


    Many karst regions are undergoing rapid population growth and expansion of urban land accompanied by increases in wastewater generation and changing patterns of nitrate (NO 3 − ) loading to surface and groundwater. We investigate variability and sources of NO 3 − in a regional karst aquifer system, the Edwards aquifer of central Texas. Samples from streams recharging the aquifer, groundwater wells, and springs were collected during 2008–12 from the Barton Springs and San Antonio segments of the Edwards aquifer and analyzed for nitrogen (N) species concentrations and NO 3 − stable isotopes (δ 15 N and δ 18 O). These data were augmented by historical data collected from 1937 to 2007. NO 3 − concentrations and discharge data indicate that short-term variability (days to months) in groundwater NO 3 − concentrations in the Barton Springs segment is controlled by occurrence of individual storms and multi-annual wet-dry cycles, whereas the lack of short-term variability in groundwater in the San Antonio segment indicates the dominance of transport along regional flow paths. In both segments, longer-term increases (years to decades) in NO 3 − concentrations cannot be attributed to hydrologic conditions; rather, isotopic ratios and land-use change indicate that septic systems and land application of treated wastewater might be the source of increased loading of NO 3 − . These results highlight the vulnerability of karst aquifers to NO 3 − contamination from urban wastewater. An analysis of N-species loading in recharge and discharge for the Barton Springs segment during 2008–10 indicates an overall mass balance in total N, but recharge contains higher concentrations of organic N and lower concentrations of NO 3 − than does discharge, consistent with nitrification of organic N within the aquifer and consumption of dissolved oxygen. This study demonstrates that subaqueous nitrification of organic N in the aquifer, as opposed to in soils, might be a

  2. Aquifer thermal energy storage in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Iihola, H; Ala-Peijari, T; Seppaenen, H


    The rapid changes and crises in the field of energy during the 1970s and 1980s have forced us to examine the use of energy more critically and to look for new ideas. Seasonal aquifer thermal energy storage (T < 100/sup 0/C) on a large scale is one of the grey areas which have not yet been extensively explored. However, projects are currently underway in a dozen countries. In Finland there have been three demonstration projects from 1974 to 1987. International co-operation under the auspices of the International Energy Agency, Annex VI, 'Environmental and Chemical Aspects of Thermal Energy Storage in Aquifers and Research and Development of Water Treatment Methods' started in 1987. The research being undertaken in 8 countries includes several elements fundamental to hydrochemistry and biochemistry.

  3. Study of Aquifer Thermal Energy Storage (United States)

    Okuyama, Masaaki; Umemiya, Hiromichi; Shibuya, Ikuko; Haga, Eiji

    Yamagata University 'Aquifer Thermal Energy Storage (ATES)' is the experimental system which has been running since 1982. From the results for along terms of experiments, we obtain many important knowledge. This paper presents the accomplishments for 16 years and the characteristics of thermal energy storage in thermal energy storage well. The conclusions show as follows. 1)In recent years, the thermal recovery factor of warm energy storage well becomes almost constant at about 60%. 2) The thermal recovery factor of cool energy storage well increases gradually and becomes at about 15%. 3) Since the ferric colloidal dam is formed in aquifer, thermal recovery factor increase year after year. 4) Back wash can remove clogging for ferric colloidal dam. 5) The apparent thermal diffusivity decrease gradually due to ferric colloidal dam.

  4. Multiple-scale hydraulic characterization of a surficial clayey aquitard overlying a regional aquifer in Louisiana (United States)

    Chapman, Steven W.; Cherry, John A.; Parker, Beth L.


    The vertical hydraulic conductivity (Kv) of a 30-m thick surficial clayey aquitard overlying a regional aquifer at an industrial site in the Mississippi River Valley in Louisiana was investigated via intensive hydraulic characterization using high resolution vertical hydraulic head profiles with temporal monitoring and laboratory tests. A study area was instrumented with a semi-circular array of piezometers at many depths in the aquitard at equal distance from a large capacity pumping well including replicate piezometers. Profiles showed negligible head differential to 20 m bgs, below which there was an abrupt change in vertical gradients over the lower 8-10 m of the aquitard. Hydraulic characteristics are strongly associated with depositional environment; the upper zone of minimal head differentials with depth and minimal variation over time correlates with Paleo-Mississippi River backswamp deposits, while the lower zone with large head differentials and slow but moderate head changes correlates with lacustrine deposits. The lower zone restricts groundwater flow between the surface and underlying regional aquifer, which is hydraulically connected to the Mississippi River. Lab tests on lacustrine samples show low Kv (8 × 10-11-4 × 10-9 m/s) bracketing field estimates (6 × 10-10 m/s) from 1-D model fits to piezometric data in response to large aquifer head changes. The slow response indicates absence of through-going open fractures in the lacustrine unit, consistent with geotechnical properties (high plasticity, normal consolidation), suggesting high integrity that protects the underlying aquifer from surficial contamination. The lack of vertical gradients in the overlying backswamp unit indicates abundant secondary permeability features (e.g. fractures, rootholes) consistent with depositional and weathering conditions. 2-D stylized transient flow simulations including both units supports this interpretation. Other published reports on surficial aquitards in the

  5. Use of Geophysical and Remote Sensing Data for Assessment of Aquifer Depletion and Related Land Deformation (United States)

    Othman, Abdullah; Sultan, Mohamed; Becker, Richard; Alsefry, Saleh; Alharbi, Talal; Gebremichael, Esayas; Alharbi, Hassan; Abdelmohsen, Karem


    An integrated approach [field, Interferometric Synthetic Aperture Radar (InSAR), hydrogeology, geodesy, and spatial analysis] was adopted to identify the nature, intensity, and spatial distribution of deformational features (sinkholes, fissures, differential settling) reported over fossil aquifers in arid lands, their controlling factors, and possible remedies. The Lower Mega Aquifer System (area 2 × 106 km2) in central and northern Arabia was used as a test site. Findings suggest that excessive groundwater extraction from the fossil aquifer is the main cause of deformation: (1) deformational features correlated spatially and/or temporally with increased agricultural development and groundwater extraction, and with a decline in water levels and groundwater storage (- 3.7 ± 0.6 km3/year); (2) earthquake events (years 1985-2016; magnitude 1-5) are largely (65% of reported earthquakes) shallow (1-5 km) and increased from 1 event/year in the early 1980s (extraction 1 km3/year), up to 13 events/year in the 1990s (average annual extraction > 6.4 km3). Results indicate that faults played a role in localizing deformation given that deformational sites and InSAR-based high subsidence rates (- 4 to - 15 mm/year) were largely found within, but not outside of, NW-SE-trending grabens bound by the Kahf fault system. Findings from the analysis of Gravity Recovery and Climate Experiment solutions indicate that sustainable extraction could be attained if groundwater extraction was reduced by 3.5-4 km3/year. This study provides replicable and cost-effective methodologies for optimum utilization of fossil aquifers and for minimizing deformation associated with their use.

  6. Stochastic Management of Non-Point Source Contamination: Joint Impact of Aquifer Heterogeneity and Well Characteristics (United States)

    Henri, C. V.; Harter, T.


    Agricultural activities are recognized as the preeminent origin of non-point source (NPS) contamination of water bodies through the leakage of nitrate, salt and agrochemicals. A large fraction of world agricultural activities and therefore NPS contamination occurs over unconsolidated alluvial deposit basins offering soil composition and topography favorable to productive farming. These basins represent also important groundwater reservoirs. The over-exploitation of aquifers coupled with groundwater pollution by agriculture-related NPS contaminant has led to a rapid deterioration of the quality of these groundwater basins. The management of groundwater contamination from NPS is challenged by the inherent complexity of aquifers systems. Contaminant transport dynamics are highly uncertain due to the heterogeneity of hydraulic parameters controlling groundwater flow. Well characteristics are also key uncertain elements affecting pollutant transport and NPS management but quantifying uncertainty in NPS management under these conditions is not well documented. Our work focuses on better understanding the joint impact of aquifer heterogeneity and pumping well characteristics (extraction rate and depth) on (1) the transport of contaminants from NPS and (2) the spatio-temporal extension of the capture zone. To do so, we generate a series of geostatistically equivalent 3D heterogeneous aquifers and simulate the flow and non-reactive solute transport from NPS to extraction wells within a stochastic framework. The propagation of the uncertainty on the hydraulic conductivity field is systematically analyzed. A sensitivity analysis of the impact of extraction well characteristics (pumping rate and screen depth) is also conducted. Results highlight the significant role that heterogeneity and well characteristics plays on management metrics. We finally show that, in case of NPS contamination, the joint impact of regional longitudinal and transverse vertical hydraulic gradients and

  7. The fate of benzotriazole pollutants in an urban oxic intergranular aquifer. (United States)

    Trček, Branka; Žigon, Dušan; Zidar, Vlasta Kramarič; Auersperger, Primož


    Benzotriazoles (BTs) are considered as Contaminants of Emerging Concern (CECs); however, information about their fate in aquifers continues to be absent. This was the focus of the present study, which provides the first evidence for relevant BTs' degradation products (BTTPs) in urban aquifers that may impact the groundwater quality. The mechanisms and biotransformation pathways of BTs were investigated in an oxic intergranular medium. The BTs and BTTPs were identified and quantified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analytical techniques based on reference standards and internal materials. The major transformation products were identified as 2-methyl-2H-benzotriazole (2-MeBT) for the degradation of 1H-benzotriazole (BT) and as 2,4-dimethyl-2H-benzotriazole (2,4-dMeBT) and 1,4-dimethyl-1H-benzotriazole (1,4-dMeBT) for the degradation of 4-methyl-1H-benzotriazole (4-MeBT), and most probably also 5-methyl-1H-benzotriazole (5-MeBT). The leakage of wastewater pipelines is most probably the source of BTs. Sediments with a lower hydraulic conductivity give rise to perched aquifer conditions that lead to the temporal storage of leaking effluents and presumably the majority of BTs' transformation processes via methylation and tautomerization. The most stable BTTPs entered the saturated zone of the aquifer, where they prevailed. Concentrations up to 1500 ng L -1 were measured for the 2,4-dMeBT, which suggest a contamination risk for groundwater that is or may be used as a source for drinking water in the case of a constant input of pollutant loads from sewer systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer

    Directory of Open Access Journals (Sweden)

    J. B. Heffernan


    Full Text Available Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and temporal variability, particularly at the scale of whole aquifers. Uncertainty in estimates of denitrification may also lead to underestimates of its effect on isotopic signatures of inorganic N, and thereby confound the inference of N source from these data. In this study, our objectives are to quantify the magnitude and variability of denitrification in the Upper Floridan Aquifer (UFA and evaluate its effect on N isotopic signatures at the regional scale. Using dual noble gas tracers (Ne, Ar to generate physical predictions of N2 gas concentrations for 112 observations from 61 UFA springs, we show that excess (i.e. denitrification-derived N2 is highly variable in space and inversely correlated with dissolved oxygen (O2. Negative relationships between O2 and δ15NNO3 across a larger dataset of 113 springs, well-constrained isotopic fractionation coefficients, and strong 15N:18O covariation further support inferences of denitrification in this uniquely organic-matter-poor system. Despite relatively low average rates, denitrification accounted for 32 % of estimated aquifer N inputs across all sampled UFA springs. Back-calculations of source δ15NNO3 based on denitrification progression suggest that isotopically-enriched nitrate (NO3 in many springs of the UFA reflects groundwater denitrification rather than urban- or animal-derived inputs.

  9. Increasing freshwater recovery upon aquifer storage : A field and modelling study of dedicated aquifer storage and recovery configurations in brackish-saline aquifers

    NARCIS (Netherlands)

    Zuurbier, Koen


    The subsurface may provide opportunities for robust, effective, sustainable, and cost-efficient freshwater management solutions. For instance, via aquifer storage and recovery (ASR; Pyne, 2005): “the storage of water in a suitable aquifer through a well during times when water is available, and the

  10. Simplified models of transport and reactions in conditions of CO2 storage in saline aquifers (United States)

    Suchodolska, Katarzyna; Labus, Krzysztof


    Simple hydrogeochemical models may serve as tools of preliminary assessment of CO2 injection and sequestraton impact on the aquifer and cap-rocks. In order to create models of reaction and transport in conditions of CO2 injection and storage, the TOUGHREACT simulator, and the Geochemist's Workbench software were applied. The chemical composition of waters for kinetic transport models based on the water - rock equilibrium calculations. Analyses of reaction and transport of substances during CO2 injection and storage period were carried out in three scenarios: one-dimensional radial model, and two-dimensional model of CO2 injection and sequestration, and one-dimensional model of aquifer - cap-rock interface. Modeling was performed in two stages. The first one simulated the immediate changes in the aquifer and insulating rocks impacted by CO2 injection (100 days in case of reaction model and 30 years in transport and reaction model), the second - enabled assessment of long-term effects of sequestration (20000 years). Reactions' quality and progress were monitored and their effects on formation porosity and sequestration capacity in form of mineral, residual and free phase of CO2 were calculated. Calibration of numerical models (including precipitation of secondary minerals, and correction of kinetics parameters) describing the initial stage of injection, was based on the experimental results. Modeling allowed to evaluate the pore space saturation with gas, changes in the composition and pH of pore waters, relationships between porosity and permeability changes and crystallization or dissolution minerals. We assessed the temporal and spatial extent of crystallization processes, and the amount of carbonates trapping. CO2 in mineral form. The calculated sequestration capacity of analyzed formations reached n·100 kg/m3 for the: dissolved phase - CO(aq), gas phase - CO2(g) and mineral phase, but as much as 101 kg/m3 for the supercritical phase - SCCO2. Processes of gas

  11. Understanding Uranium Behavior in a Reduced Aquifer (United States)

    Janot, N.; Lezama-Pacheco, J. S.; Williams, K. H.; Bernier-Latmani, R.; Long, P. E.; Davis, J. A.; Fox, P. M.; Yang, L.; Giammar, D.; Cerrato, J. M.; Bargar, J.


    Uranium contamination of groundwater is a concern at several US Department of Energy sites, such Old Rifle, CO. Uranium transport in the environment is mainly controlled by its oxidation state, since oxidized U(VI) is relatively mobile, whereas U(IV) is relatively insoluble. Bio-remediation of contaminated aquifers aims at immobilizing uranium in a reduced form. Previous laboratory and field studies have shown that adding electron donor (lactate, acetate, ethanol) to groundwater stimulates the activity of metal- and sulfate-reducing bacteria, which promotes U(VI) reduction in contaminated aquifers. However, obtaining information on chemical and physical forms of U, Fe and S species for sediments biostimulated in the field, as well as kinetic parameters such as U(VI) reduction rate, is challenging due to the low concentration of uranium in the aquifers (typically bio-remediation experiment at the Old Rifle site, CO, from early iron-reducing conditions to the transition to sulfate-reducing conditions. Several in-well chromatographic columns packed with sediment were deployed and were sampled at different days after the start of bio-reduction. X-ray absorption spectroscopy and X-ray microscopy were used to obtain information on Fe, S and U speciation and distribution. Chemical extractions of the reduced sediments have also been performed, to determine the rate of Fe(II) and U(IV) accumulation.

  12. Carbon-14 measurements in aquifers with methane

    International Nuclear Information System (INIS)

    Barker, J.F.; Fritz, P.; Brown, R.M.


    A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 Csub(CH 4 )>-45 per mille and microbially produced or biogenic methane had delta 13 Csub(CH 4 ) 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. The adjusted groundwater ages can be explained in terms of the complex hydrogeology of this aquifer, but also indicate that these conceptual models must be more rigorously tested to evaluate their appropriateness. (author)

  13. 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


    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.

  14. The Use of Ionizing Radiation to Prepare Polymeric Agro-waste Composite for Sandy Soil Application

    International Nuclear Information System (INIS)

    Elhady, M.A.; Elnahas, H.H.; Meligi, G.A.; Ammar, A.H.


    Super absorbent hydrogel composite (SHC) by radiation induced crosslinking of polyacrylamide (PAAM)/ rice straw (RS) composite and hydrophilic membrane system based on polyvinyl alcohol (PVA) for possible applications in agricultural field of sandy soil was studied. The factors affecting the quick and capacity for retaining irrigated water of swelling behaviour of prepared hydrogel composite through hydrophilic membrane system and increasing foaming/ porosity of the SHC were studied. The mechanism for this is most likely a prevention of irrigated water to pass through sandy particles for a time ranged from 20 to 40 min for the fluid uptake capacity and swelling of the SHC to take and swelling place without almost any loss of irrigated water. Effect of acid/ alkalinity (PH) and salt concentration were investigation.

  15. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    DEFF Research Database (Denmark)

    Bühring, Solveig I.; Ehrenhauss, Sandra; Kamp, Anja


    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...... 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....... 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...

  16. Pore-size distribution and compressibility of coarse sandy subsoil with added biochar

    DEFF Research Database (Denmark)

    Petersen, C. T.; Hansen, E.; Larsen, H. H.


    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...

  17. Nitrogen and Carbon Leaching in Repacked Sandy Soil with Added Fine Particulate Biochar

    DEFF Research Database (Denmark)

    Bruun, Esben W.; Petersen, Carsten; Strobel, Bjarne W.


    Biochar amendment to soil may affect N turnover and retention, and may cause translocation of dissolved and particulate C. We investigated effects of three fine particulate biochars made of wheat (Triticum aestivum L.) straw (one by slow pyrolysis and two by fast pyrolysis) on N and C leaching from...... repacked sandy soil columns (length: 51 cm). Biochar (2 wt%), ammonium fertilizer (NH4+, amount corresponding to 300 kg N ha-1) and an inert tracer (bromide) were added to a 3-cm top layer of sandy loam, and the columns were then irrigated with constant rate (36 mm d-1) for 15 d. The total amount...... of leachate came to about 3.0 water filled pore volumes (WFPVs). Our study revealed a high mobility of labile C components originating from the fine particulate fast pyrolysis biochar. This finding highlights a potential risk of C leaching coupled with the use of fast pyrolysis biochars for soil amendment...

  18. Firearms and accidental deaths: Evidence from the aftermath of the Sandy Hook school shooting. (United States)

    Levine, Phillip B; McKnight, Robin


    Exposure to firearms increased substantially after the December 2012 shooting at Sandy Hook Elementary School in Newtown, Connecticut, where 20 children and 6 adults were killed. Gun sales spiked by 3 million, on the basis of the increase in the number of background checks for firearm purchases. Google searches for buying and cleaning guns increased. We used Vital Statistics mortality data to examine whether a spike in accidental firearm deaths occurred at the same time as the greater exposure to firearms. We also assessed whether the increase in these deaths was larger in those states where the spike in gun sales per capita was larger. We find that an additional 60 deaths overall, including 20 children, resulted from unintentional shootings in the immediate aftermath of Sandy Hook. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  19. Tropical to extratropical: Marine environmental changes associated with Superstorm Sandy prior to its landfall (United States)

    Zambon, Joseph B.; He, Ruoying; Warner, John C.


    Superstorm Sandy was a massive storm that impacted the U.S. East Coast on 22-31 October 2012, generating large waves, record storm surges, and major damage. The Coupled Ocean-Atmosphere-Wave-Sediment Transport modeling system was applied to hindcast this storm. Sensitivity experiments with increasing complexity of air-sea-wave coupling were used to depict characteristics of this immense storm as it underwent tropical to extratropical transition. Regardless of coupling complexity, model-simulated tracks were all similar to the observations, suggesting the storm track was largely determined by large-scale synoptic atmospheric circulation, rather than by local processes resolved through model coupling. Analyses of the sea surface temperature, ocean heat content, and upper atmospheric shear parameters showed that as a result of the extratropical transition and despite the storm encountering much cooler shelf water, its intensity and strength were not significantly impacted. Ocean coupling was not as important as originally thought for Sandy.

  20. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh


    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...... compost had greater effect in improving tomato productivity. A decade-long application of composts on loamy sand improved basic chemical and physical properties which were reflected in increased fruit yield in tomato. Since no negative effect of compost was observed, we suggest that sandy soils may serve...... and greenhouse tomato productivity. Disturbed and intact soil samples were taken from a decade-long compost field experiment on loamy sand with three compost types at application rate of 30 m3 ha-1 yr-1 (7.5 ton ha-1 yr-1). The soils were characterized for chemical and physical properties. Tomato was planted...


    Directory of Open Access Journals (Sweden)

    Katarzyna Kamińska


    Full Text Available The paper aimed at the determination of the California Bearing Ratio of a stabilised and unstabilised fine-grained mineral soil. A clayey-sandy silt with the addition of 3, 6 and 10% of road stabilisers Solidex and Solidex A was used for the tests. The tests were carried out in the press Tritech 50 at the loading of 22 and 44 N. The stabilised samples were subjected to 7-days treatment, whereas unstabilised 4-days treatment. Stabilization with the applied road binders brought positive effects, there occurred a significant improvement in the mechanical properties of the clayey-sandy silt. The better binder, which significantly increased the value of the CBR ratio, was Solidex A. The use of hydraulic binders is of a great importance in road building, because their addition improves the mechanical properties of weaker mineral soils.

  2. Hurricane Sandy science plan: impacts of environmental quality and persisting contaminant exposure (United States)

    Caskie, Sarah A.


    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

  3. Hurricane Sandy science plan: impacts to coastal ecosystems, habitats, and fish and wildlife (United States)

    Campbell, Warren H.


    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

  4. Fine organic particles in a sandy beach system (Puck Bay, Baltic Sea

    Directory of Open Access Journals (Sweden)

    Lech Kotwicki


    Full Text Available A total of over 550 samples of particulate organic matter (POM were obtained from swash and groundwater samples taken on a monthly basis from seven localities on the sandy shores of Puck Bay in 2002 and 2003. Sandy sediment cores from the swash zone were collected to assess the amount of POM in the pore waters. The mean annual concentrations of POM varied between localities from 20 to 500 mg in groundwater and from 6 to 200 mg dm-3 in swash water. The carbon/nitrogen (C/N ratio in suspended matter was always higher in groundwater (annual mean 12 than in swash water (annual mean 7. The C/N ratio indicates a local, algal origin of POM in the shallow coastal zone.

  5. Hydrology of the shallow aquifer and uppermost semiconfined aquifer near El Paso, Texas (United States)

    White, D.E.; Baker, E.T.; Sperka, Roger


    The availability of fresh ground water in El Paso and adjacent areas that is needed to meet increased demand for water supply concerns local, State, and Federal agencies. The Hueco bolson is the principal aquifer in the El Paso area. Starting in the early 1900s and continuing to the 1950s, most of the municipal and industrial water supply in El Paso was pumped from the Hueco bolson aquifer from wells in and near the Rio Grande Valley and the international border. The Rio Grande is the principal surface-water feature in the El Paso area, and a major source of recharge to the shallow aquifer (Rio Grande alluvium) within the study area is leakage of flow from the Rio Grande.

  6. Seasonal variations measured by TDR and GPR on an anthropogenic sandy soil and the implications for utility detection (United States)

    Curioni, Giulio; Chapman, David N.; Metje, Nicole


    The electromagnetic (EM) soil properties are dynamic variables that can change considerably over time, and they fundamentally affect the performance of Ground Penetrating Radar (GPR). However, long-term field studies are remarkably rare and records of the EM soil properties and their seasonal variation are largely absent from the literature. This research explores the extent of the seasonal variation of the apparent permittivity (Ka) and bulk electrical conductivity (BEC) measured by Time Domain Reflectometry (TDR) and their impact on GPR results, with a particularly important application to utility detection. A bespoke TDR field monitoring station was specifically developed and installed in an anthropogenic sandy soil in the UK for 22 months. The relationship between the temporal variation of the EM soil properties and GPR performance has been qualitatively assessed, highlighting notably degradation of the GPR images during wet periods and a few days after significant rainfall events following dry periods. Significantly, it was shown that by assuming arbitrary average values (i.e. not extreme values) of Ka and BEC which do not often reflect the typical conditions of the soil, it can lead to significant inaccuracies in the estimation of the depth of buried targets, with errors potentially up to approximately 30% even over a depth of 0.50 m (where GPR is expected to be most accurate). It is therefore recommended to measure or assess the soil conditions during GPR surveys, and if this is not possible to use typical wet and dry Ka values reported in the literature for the soil expected at the site, to improve confidence in estimations of target depths.

  7. The seaweed fly (Coelopidae) can facilitate environmental survival and transmission of E. coli O157 at sandy beaches. (United States)

    Swinscoe, Isobel; Oliver, David M; Gilburn, Andre S; Quilliam, Richard S


    The sustainable management of recreational beaches is essential for minimising risk of human exposure to microbial pathogens whilst simultaneously maintaining valuable ecosystem services. Decaying seaweed on public beaches is gaining recognition as a substrate for microbial contamination, and is a potentially significant reservoir for human pathogens in close proximity to beach users. Closely associated with beds of decaying seaweed are dense populations of the seaweed fly (Coelopidae), which could influence the spatio-temporal fate of seaweed-associated human pathogens within beach environments. Replicated mesocosms containing seaweed inoculated with a bioluminescent strain of the zoonotic pathogen E. coli O157:H7, were used to determine the effects of two seaweed flies, Coelopa frigida and C. pilipes, on E. coli O157:H7 survival dynamics. Multiple generations of seaweed flies and their larvae significantly enhanced persistence of E. coli O157:H7 in simulated wrack habitats, demonstrating that both female and male C. frigida flies are capable of transferring E. coli O157:H7 between individual wrack beds and into the sand. Adult fly faeces can contain significant concentrations of E. coli O157:H7, which suggests they are capable of acting as biological vectors and bridge hosts between wrack habitats and other seaweed fly populations, and facilitate the persistence and dispersal of E. coli O157:H7 in sandy beach environments. This study provides the first evidence that seaweed fly populations inhabiting natural wrack beds contaminated with the human pathogen E. coli O157:H7 have the capacity to amplify the hazard source, and therefore potential transmission risk, to beach users exposed to seaweed and sand in the intertidal zone. The risk to public health from seaweed flies and decaying wrack beds is usually limited by human avoidance behaviour; however, seaweed fly migration and nuisance inland plagues in urban areas could increase human exposure routes beyond the

  8. Long-Term Observations of Dust Storms in Sandy Desert Environments (United States)

    Yun, Hye-Won; Kim, Jung-Rack; Choi, Yun-Soo


    Mineral dust occupies the largest portion of atmospheric aerosol. Considering the numerous risks that dust poses for socioeconomic and anthropogenic activities, it is crucial to understand sandy desert environments, which frequently generate dust storms and act as a primary source of atmospheric aerosol. To identify mineral aerosol mechanisms, it is essential to monitor desert environmental factors involving dust storm generation in the long term. In this study, we focused on two major environmental factors: local surface roughness and soil moisture. Since installments of ground observation networks in sandy deserts are unfeasible, remote sensing techniques for mining desert environmental factors were employed. The test area was established within the Badain Jaran and Kubuqi Deserts in Inner Mongolia, China, where significant seasonal aeolian processes emit mineral dust that influences all of East Asia. To trace local surface roughness, we employed a multi-angle imaging spectroradiometer (MISR) image sequence to extract multi-angle viewing (MAV) topographic parameters such as normalized difference angular index, which represents characteristics of the target desert topography. The backscattering coefficient from various space-borne SAR and stereotopography were compared with MAV observations to determine calibrated local surface roughness. Soil moisture extraction techniques from InSAR-phase coherence stacks were developed and compiled with advanced scatterometer (ASCAT) soil moisture data. Combined with metrological information such as the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA interim, correlations between intensity of sand dune activity as a proxy of aeolian processes in desert environments, surface wind conditions, and surface soil moisture were traced. Overall, we have confirmed that tracking sandy desert aeolian environments for long-term observations is feasible with space-borne, multi-sensor observations when combined with

  9. Behavioural adaptations of two sympatric sandhoppers living on a mesotidal European Atlantic sandy beach (United States)

    Bessa, Filipa; Marques, João Carlos; Scapini, Felicita


    Behavioural adaptations of supralittoral species on sandy beaches are expressed as responses to environmental changes and constitute a key factor in their survival and evolution. Two sympatric talitrid amphipods (Talitrus saltator and Britorchestia brito) from a mesotidal exposed sandy beach on the European Atlantic coast (Portugal) were compared as regards orientation and littoral zonation patterns under natural conditions. Orientation experiments were carried out during spring and summer 2011 and 2012 at Quiaios beach, a highly dynamic exposed sandy beach. Multiple regression models were fitted to the angular data and the environmental effects on orientation were investigated for each species. Both talitrids were shown to be well orientated towards the shoreline and finely adapted to the mesotidal environment but a different use of local cues and climatic features between the two species was apparent. T. saltator showed a lower precision in the orientation performance (with a bimodal distribution sea- and land-wards), with less dependence on the sun cues and higher dependence on climatic features. In addition, the zonation of T. saltator was across the land-sea axis during both seasons. For B. brito the landscape vision, sun visibility and the tidal range enhanced the orientation to the shoreline. On this mesotidal Atlantic beach, T. saltator appeared to have a more flexible orientation with respect to B. brito, which appeared to be more dependent on the conditions offered by the intertidal zone, a behaviour confirmed by its restricted zonation below the high tide mark. Consequently, T. saltator showed a more flexible behaviour that may be considered an important evolutionary adaptation to dynamic and mesotidal sandy beaches.

  10. Sensitivity analysis of the surface water- groundwater interaction for the sandy area of the Netherlands


    Gomez del Campo, E.; Jousma, G.; Massop, H.T.L.


    The "Sensitivity Analysis of the Surface Water- Groundwater Interaction for the Sandy Area of the Netherlands" was carried out in the framework of a bilateral research project in support of the implementation of a nationwide geohydrological information system (REGIS) in the Netherlands. This project, conducted in cooperation between the TNO Institute for Applied Scientific Research (IGG-TNO) and !he Winand Staring Centre for Integrated Land, Soil and Water Research (SC-DLO), is aimed at defin...



    Rasna Sharma*, Dr. M.K. Trivedi


    This paper presents the experimental determination of variability in permeability of sandy silt soil by blending with fly ash. The grain size, porosity, structure of the soil, specific gravity of the soil, viscosity and temperature are important factors in varying the permeability of the soil. Permeability is the flow conduction property of the soil. The void ratio with in the soil plays a vital role in varying the permeability. By blending with finer grains like fly ash in the soil with sand...

  12. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil


    Zhuang, Wenhua; Li, Longguo; Liu, Chao


    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 reduc...

  13. The Influence of Shoreline Curvature on Rates of Shoreline Change on Sandy Coasts (United States)

    Murray, A. B.; Lauzon, R.; Cheng, S.; Liu, J.; Lazarus, E.


    The sandy, low-lying barrier islands which characterize much of the US East and Gulf coasts are popular spots to live and vacation, and are often heavily developed. However, sandy shorelines and barriers are also naturally mobile landforms, which are vulnerable to sea level rise and storms and can experience high rates of shoreline change. Many previous studies have attempted to understand and quantify the factors that contribute to those rates of shoreline change, such as grain size, underlying geology, sea level rise, and anthropogenic modification. Shoreline curvature has not been considered in such analyses, but previous research has demonstrated that subtle coastline curvature (and therefore alongshore variation in relative offshore wave angle) can result in gradients in net alongshore transport that cause significant shoreline erosion or accretion. Here we present the results of a spatially extensive analysis of the correlation between shoreline curvature and shoreline change rates for the sandy shorelines of the US East and Gulf coasts. We find that, for wave-dominated sandy coasts where nourishment and shoreline stabilization do not dominate the shoreline change signal (such as parts of Texas, North Carolina, and Florida), there is a significant negative correlation between shoreline curvature and shoreline change rates over 1 - 5 km and decadal to centurial space and time scales. This correlation indicates that a portion of the coastal erosion (and accretion) observed in these areas can be explained by the smoothing of subtle coastline curvature by gradients in alongshore transport, and suggests that shoreline curvature should be included in future attempts to understand historical and future rates of shoreline change. Shoreline stabilization, especially through beach nourishment, complicates the relationship between curvature and shoreline change. Beach construction during nourishment creates a seaward convex curvature in the part of the shoreline moves

  14. Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

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    M.I. Choudhary


    Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

  15. Effects of plant cover on soil N mineralization during the growing season in a sandy soil (United States)

    Yao, Y.; Shao, M.; Wei, X.; Fu, X.


    Soil nitrogen (N) mineralization and its availability plays a vital role in regulating ecosystem productivity and C cycling, particularly in semiarid and desertified ecosystems. To determine the effect of plant cover on N turnover in a sandy soil ecosystem, we measured soil N mineralization and inorganic N pools in soil solution during growing season in a sandy soil covered with various plant species (Artemisia desertorum, Salix psammophila, and Caragana korshinskii). A bare sandy soil without any plant was selected as control. Inorganic N pools and N mineralization rates decreased overtime during the growing season, and were not affected by soil depth in bare land soils, but were significantly higher at the 0-10 cm layer than those at the 10-20 cm soil layer under any plant species. Soil inorganic N pool was dominated by ammonium, and N mineralization was dominated by nitrification regardless of soil depth and plant cover. Soils under C. korshinskii have significant higher inorganic N pools and N mineralization rate than soils under bare land and A. desertorum and S. psammophila, and the effects of plant cover were greater at the 0-10 cm soil layer than at the 10-20 cm layer. The effects of C. korshinskii on soil inorganic N pools and mineralization rate varied with the stage of growing season, with greater effects on N pools in the middle growing season, and greater effects on mineralization rate at the last half of the growing season. The results from this study indicate that introduction of C. korshinskii has the potential to increase soil N turnover and availability in sandy soils, and thus to decrease N limitation. Caragana korshinskii is therefore recommend for the remediation of the desertified land.

  16. Impact of Superstorm Sandy on Medicare Patients' Utilization of Hospitals and Emergency Departments. (United States)

    Stryckman, Benoit; Walsh, Lauren; Carr, Brendan G; Hupert, Nathaniel; Lurie, Nicole


    National health security requires that healthcare facilities be prepared to provide rapid, effective emergency and trauma care to all patients affected by a catastrophic event. We sought to quantify changes in healthcare utilization patterns for an at-risk Medicare population before, during, and after Superstorm Sandy's 2012 landfall in New Jersey (NJ). This study is a retrospective cohort study of Medicare beneficiaries impacted by Superstorm Sandy. We compared hospital emergency department (ED) and healthcare facility inpatient utilization in the weeks before and after Superstorm Sandy landfall using a 20% random sample of Medicare fee-for-service beneficiaries continuously enrolled in 2011 and 2012 (N=224,116). Outcome measures were pre-storm discharges (or transfers), average length of stay, service intensity weight, and post-storm ED visits resulting in either discharge or hospital admission. In the pre-storm week, hospital transfers from skilled nursing facilities (SNF) increased by 39% and inpatient discharges had a 0.3 day decreased mean length of stay compared to the prior year. In the post-storm week, ED visits increased by 14% statewide; of these additional "surge" patients, 20% were admitted to the hospital. The increase in ED demand was more than double the statewide average in the most highly impacted coastal regions (35% versus 14%). Superstorm Sandy impacted both pre- and post-storm patient movement in New Jersey; post-landfall ED surge was associated with overall storm impact, which was greatest in coastal counties. A significant increase in the number and severity of pre-storm transfer patients, in particular from SNF, as well as in post-storm ED visits and inpatient admissions, draws attention to the importance of collaborative regional approaches to healthcare in large-scale events.

  17. Characterization of microbial and metal contamination in flooded New York City neighborhoods following Superstorm Sandy (United States)

    Dueker, M.; O'Mullan, G. D.; Sahajpal, R.


    Large scale flooding of waterfront neighborhoods occurred in New York City (NYC) during Superstorm Sandy. While NYC waterways commonly experience combined sewer overflow (CSO) and associated water quality degradation during rain storms, Superstorm Sandy was unique in that these potentially contaminated waters were transported over the banks and into city streets and buildings. Sampling of waterways, storm debris on city streets, and flood water trapped in building basements occurred in the days following Sandy, including in neighborhoods bordering the Gowanus Canal and Newtown Creek, which are both Superfund sites known to frequently contain high levels of sewage associated bacteria and metal contamination. Samples enumerated for the sewage indicating bacterium, Enterococcus, suggest that well-flushed waterways recovered quickly from sewage contamination in the days following the storm, with Enterococci concentrations similar to background levels measured before flooding occurred. In contrast, storm debris on city streets and waters from flooded basements had much higher levels of sewage-associated bacteria days after flooding occurred. Analysis of 180,000 bacterial 16S rRNA gene sequences obtained from flood water samples and flood debris confirmed the presence of bacterial genera often associated with sewage impacted samples (e.g. Escherichia, Streptococcus, Clostridium, Trichococcus, Aeromonas) and a community composition similar to CSO discharge. Elemental analysis suggests low levels of metal contamination in most flood water, but much higher levels of Cu, Pb, and Cr were found in leach from some storm debris samples found adjacent to the Newtown Creek and Gowanus Canal superfund sites. These data suggest a rapid recovery of water quality in local waterways after Superstorm Sandy, but that trapped flood water and debris samples in urban neighborhoods retained elevated levels of microbial sewage pollution, and in some cases metal pollution, days after that

  18. Micro- and mesozooplankton communities in the surf zone of a tropical sandy beach (Equatorial Southwestern Atlantic)


    Oliveira-Santos, Nivia Maria; Martins-Garcia, Tatiane; Oliveira-Soares, Marcelo de


    Sandy beaches constitute important ecosystems from both ecological and socioeconomic standpoints. The ecosystems of tropical zones present a high diversity and are sensible to global climatic changes, as well as to local impacts. Despite its relevance, researches on biodiversity and existing ecological processes, like size distribution of plankton communities, in these regions are often neglected. Here, the first results of a study on the structure of zooplankton communities in a tropical san...

  19. Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau. (United States)

    Zhu, Yajuan; Wang, Guojie; Li, Renqiang


    Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land.

  20. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes.

    Directory of Open Access Journals (Sweden)

    Wil Lieberman-Cribbin

    Full Text Available 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.

  1. Three new records of Desmodorids (Nematoda, Desmodoridae) from sandy seabeds of the Canary islands


    Riera, Rodrigo; Núñez, Jorge; Brito, María del Carmen


    In an ecological study of meiofaunal assemblages in two locations (Los Abrigos and Los Cristianos) of Tenerife (Canary Islands, NE Atlantic Ocean), several desmodorid species were found throughout the study period. Three species belonging to the family Desmodoridae were collected in intertidal and shallow subtidal sandy seabeds. These species were Desmodorella aff. tenuispiculum Allgen, 1928, Metachromadora sp. and Spirinia parasitifera Bastian, 1865. Descriptions, figures and tables with mer...

  2. The Method of Calculating the Settlement of Weak Ground Strengthened with the Reinforced Sandy Piles

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    Maltseva Tatyana


    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.

  3. 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New York City) (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....

  4. Role of environmental heterogeneity in structuring the macrobenthic community in a tropical sandy beach, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.; Ingole, B.S.; Ganesan, P.; Sautya, S.; Nanajkar, M.

    In most ecosystems, community structure emerges as a result of the complex interaction between biotic and environmental variables. Sandy beaches connected to adjacent ecosystem like estuaries/creeks provide an opportunity to understand the role...

  5. Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013. (United States)

    Romanok, Kristin M.; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.


    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.

  6. Recharge and Aquifer Response: Manukan Island’s Aquifer, Sabah, Malaysia

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    Sarva Mangala Praveena


    Full Text Available Manukan Island is a small island located in North-West of Sabah, Malaysia was used as a case study area for numerical modeling of an aquifer response to recharge and pumping rates. The results in this study present the variations of recharge into the aquifer under the prediction simulations. The recharge rate increases the water level as indicated by hydraulic heads. This shows that it can alter groundwater of Manukan Island which has been suffering from an overexploration in its unconfined the aquifer. The increase in recharge rate (from 600 mm/year to 750 mm/year increases the water level indicated by hydraulic heads. A reduction in pumping rate (from 0.072 m3/day to 0.058 m3/day not only increases the amount of water levels in aquifer but also reduces the supply hence a deficit in supply. The increase in hydraulic heads depends on the percentage reduction of pumping and recharges rates. The well water has 1978.3 mg/L chloride with current pumping (0.072 m3/day and recharge rates (600 mm/year. However, with an increased of recharge rate and current pumping rate it has decreased about 1.13%. In addition, reduction in pumping rate made the chloride concentration decreased about 2.8%. In general, a reduction in pumping with an increase in recharge rate leads to a decreased in chloride concentrations within the vicinity of cone of depression. Next, to further develop the numerical model, the model should focus on climate change variables such as consequences of climate change are increase in air temperature, increase in sea surface temperature, and more extreme weather conditions. These parameters are considered critical parameters for climate change impact modeling in aquifers. The behavior of the aquifer and its sustainable pumping rate can be done by applying a computer modeling component.

  7. Characterization of Carbon Monoxide Exposure During Hurricane Sandy and Subsequent Nor'easter. (United States)

    Schnall, Amy; Law, Royal; Heinzerling, Amy; Sircar, Kanta; Damon, Scott; Yip, Fuyuen; Schier, Josh; Bayleyegn, Tesfaye; Wolkin, Amy


    Carbon monoxide (CO) is an odorless, colorless gas produced by fossil fuel combustion. On October 29, 2012, Hurricane Sandy moved ashore near Atlantic City, New Jersey, causing widespread morbidity and mortality, $30 to $50 billion in economic damage, and 8.5 million households to be without power. The combination of power outages and unusually low temperatures led people to use alternate power sources, placing many at risk for CO exposure. We examined Hurricane Sandy-related CO exposures from multiple perspectives to help identify risk factors and develop strategies to prevent future exposures. This report combined data from 3 separate sources (health departments, poison centers via the National Poison Data System, and state and local public information officers). Results indicated that the number of CO exposures in the wake of Hurricane Sandy was significantly greater than in previous years. The persons affected were mostly females and those in younger age categories and, despite messaging, most CO exposures occurred from improper generator use. Our findings emphasize the continued importance of CO-related communication and ongoing surveillance of CO exposures to support public health response and prevention during and after disasters. Additionally, regional poison centers can be a critical resource for potential on-site management, public health promotion, and disaster-related CO exposure surveillance. (Disaster Med Public Health Preparedness. 2017;11:562-567).

  8. Hurricane Sandy Exposure Alters the Development of Neural Reactivity to Negative Stimuli in Children. (United States)

    Kessel, Ellen M; Nelson, Brady D; Kujawa, Autumn; Hajcak, Greg; Kotov, Roman; Bromet, Evelyn J; Carlson, Gabrielle A; Klein, Daniel N


    This study examined whether exposure to Hurricane Sandy-related stressors altered children's brain response to emotional information. An average of 8 months (M age  = 9.19) before and 9 months after (M age  = 10.95) Hurricane Sandy, 77 children experiencing high (n = 37) and low (n = 40) levels of hurricane-related stress exposure completed a task in which the late positive potential, a neural index of emotional reactivity, was measured in response to pleasant and unpleasant, compared to neutral, images. From pre- to post-Hurricane Sandy, children with high stress exposure failed to show the same decrease in emotional reactivity to unpleasant versus neutral stimuli as those with low stress exposure. Results provide compelling evidence that exposure to natural disaster-related stressors alters neural emotional reactivity to negatively valenced information. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  9. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

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    Baille Wiebke


    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.

  10. [Introduction of upland rice cultivars to eastern Keerqin sandy land and their biological characteristics]. (United States)

    Zeng, Dehui; Zhang, Chunxing; Wang, Guirong; Fan, Zhiping


    Developing water-saving rice cultivation is one important strategy for food security in China. This paper reported the experimental results of introducing six upland rice cultivars to eastern Keerqin sandy land. The field experiment results showed that under the condition of 60% water-saving, the yield of cultivars XH 95-13 and XH 95-13-6 was 10.2% and 5.5% higher than the control, respectively, while other four cultivars decreased by 6.7%-18.6%. Economically, all the cultivars except JP 121 had a higher income than the control, and the profitability of cultivars XH 95-13 and XH 95-13-6 reached 24.0% and 19.3%, respectively. The water productivity of all the six cultivars was over 0.566 kg x m(-3), increased by 59.89%-116.38%. Pot experiment showed that 12.1%-16.3% of soil moisture in 0-15 cm layer was beneficial to the growth of upland rice. In eastern Keerqin sandy land, effective tillers occurred before July 18. In brief, upland rice production could be extensively applicable in eastern Keerqin sandy land to gradually alternate the traditional lowland rice cultivation with continuous flooding, and save much underground water.

  11. What Happened to Our Environment and Mental Health as a Result of Hurricane Sandy? (United States)

    Lin, Shao; Lu, Yi; Justino, John; Dong, Guanghui; Lauper, Ursula


    This study describes findings of the impacts of Hurricane Sandy on environmental factors including power outages, air quality, water quality, and weather factors and how these affected mental health during the hurricane. An ecological study was conducted at the county level to describe changes in environmental factors-especially power outages-and their relationships to emergency department (ED) visits for mental health problems by use of a Poisson regression model. We found that many environmental hazards occurred as co-exposures during Hurricane Sandy in addition to flooding. Mental health ED visits corresponded with the peak of maximum daily power blackouts, with a 3-day lag, and were positively associated with power blackouts in Bronx (prevalence ratio [PR]: 8.82, 95% confidence interval [CI]: 1.27-61.42) and Queens (PR: 2.47, 95% CI: 1.05-5.82) counties. A possible dose-response relationship was found between the quantile of maximum blackout percentage and the risk of mental health in the Bronx. We found that multiple co-environmental hazards occurred during Hurricane Sandy, especially power blackouts that mediated this disaster's impacts. The effects of power outage on mental health had large geographic variations and were substantial, especially in communities with low sociodemographic status. These findings may provide new insights for future disaster response and preparedness efforts. (Disaster Med Public Health Preparedness. 2016;10:314-319).

  12. Diversity of Sarcosaprophagous Calyptratae (Diptera) on Sandy Beaches Exposed to Increasing Levels of Urbanization in Brazil. (United States)

    Barbosa, Taciano Moura; Carmo, Rodrigo Felipe Rodrigues; Silva, Leonardo Pereira; Sales, Raissa Guerra; Vasconcelos, Simao Dias


    Sandy beaches are among the most impacted ecosystems worldwide, and the effects of urbanization on the biodiversity of these habitats are largely unknown, particularly in Brazil. We investigated the composition and structure of assemblages of sarcosaprophagous insects (Diptera: Calliphoridae, Sarcophagidae, and Muscidae) on six sandy beaches exposed to differential levels of human impact in Pernambuco State, Brazil. In total, 20,672 adults of 40 species were collected, of which 70% were Calliphoridae. Sarcophagidae had the highest diversity with 26 species of nine genera. A strong overlap in the composition of the assemblages across the six beaches was observed, with only a few species being restricted to one type of beach. The flesh flies Dexosarcophaga carvalhoi (Lopes), Peckia intermutans (Walker), and Titanogrypa larvicida (Lopes) occurred exclusively in beaches under low anthropogenic impact. Species with strong medical and veterinary importance such as Synthesiomyia nudiseta (Wulp) occurred even in beaches under low human presence. The invasive species Chrysomya albiceps (Wiedemann) and Chrysomya megacephala (F.) (Calliphoridae) were dominant in all beaches, which exposes the vulnerability of sandy beaches to exotic species. Our data imply that sarcosaprophagous flies can be used as early biological indicators to suggest urbanization in coastal environments. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email:

  13. 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.

  14. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy. (United States)

    Good, Stephen P; Mallia, Derek V; Lin, John C; Bowen, Gabriel J


    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(18)O, > 160‰ for δ(2)H) 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.

  15. Validation of regression models for nitrate concentrations in the upper groundwater in sandy soils

    International Nuclear Information System (INIS)

    Sonneveld, M.P.W.; Brus, D.J.; Roelsma, J.


    For Dutch sandy regions, linear regression models have been developed that predict nitrate concentrations in the upper groundwater on the basis of residual nitrate contents in the soil in autumn. The objective of our study was to validate these regression models for one particular sandy region dominated by dairy farming. No data from this area were used for calibrating the regression models. The model was validated by additional probability sampling. This sample was used to estimate errors in 1) the predicted areal fractions where the EU standard of 50 mg l -1 is exceeded for farms with low N surpluses (ALT) and farms with higher N surpluses (REF); 2) predicted cumulative frequency distributions of nitrate concentration for both groups of farms. Both the errors in the predicted areal fractions as well as the errors in the predicted cumulative frequency distributions indicate that the regression models are invalid for the sandy soils of this study area. - This study indicates that linear regression models that predict nitrate concentrations in the upper groundwater using residual soil N contents should be applied with care.

  16. A DOM Odyssey: The Tale of Molecular Transformations in an Aquifer near Bemidji, MN (United States)

    Podgorski, D. C.; Zito, P.; Smith, D. F.; Cao, X.; Schmidt-Rohr, K.; Wagner, S.; Stubbins, A.; Aiken, G.; Cozzarelli, I.; Bekins, B. A.; Spencer, R. G.


    Analytical methods including fluorescence spectroscopy, NMR spectroscopy, and ultrahigh resolution mass spectrometry have significantly advanced the understanding of compositional controls on dissolved organic matter (DOM) processing and fate. Yet, we still heavily rely on extrapolation of chemical changes identified at the edges of the compositional continuum (i.e., endmembers) to assess DOM reactivity and stability. While extrapolation of chemical transformations is useful for determining relative changes in DOM composition, a comprehensive understanding of the underlying core structures and composition is required to develop advanced biogeochemical models. Studying DOM from natural systems is complicated by many variables associated with an open system including input from multiple sources, simultaneous photo-alteration and microbial processing, and obtaining samples that cover high spatial and temporal resolution. A 38-year biodegradation study at the National Crude Oil Spill Research site near Bemidji, MN provides a unique opportunity to monitor DOM in a relatively closed system. An extensively characterized 1 m thick oil body is confined to a 25 x 75 m2 area at the water table in the aquifer. Oxidized metabolites partition from the oil into the underlying aquifer increase the DOC concentration to > 100 ppm from molecular formulas with O/C and H/C similar to those associated with the `island of stability'. Samples collected spatially from the DOM plume between these two endmembers provide sufficient temporal resolution to model both DOC concentration and DOM composition as a result of biodegradation.

  17. An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil


    Weijing Yao; Jianyong Pang; Yushan Liu


    Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry inject...

  18. Characteristics of Southern California coastal aquifer systems (United States)

    Edwards, B.D.; Hanson, R.T.; Reichard, E.G.; Johnson, T.A.


    Most groundwater produced within coastal Southern California occurs within three main types of siliciclastic basins: (1) deep (>600 m), elongate basins of the Transverse Ranges Physiographic Province, where basin axes and related fluvial systems strike parallel to tectonic structure, (2) deep (>6000 m), broad basins of the Los Angeles and Orange County coastal plains in the northern part of the Peninsular Ranges Physiographic Province, where fluvial systems cut across tectonic structure at high angles, and (3) shallow (75-350 m), relatively narrow fluvial valleys of the generally mountainous southern part of the Peninsular Ranges Physiographic Province in San Diego County. Groundwater pumped for agricultural, industrial, municipal, and private use from coastal aquifers within these basins increased with population growth since the mid-1850s. Despite a significant influx of imported water into the region in recent times, groundwater, although reduced as a component of total consumption, still constitutes a significant component of water supply. Historically, overdraft from the aquifers has caused land surface subsidence, flow between water basins with related migration of groundwater contaminants, as well as seawater intrusion into many shallow coastal aquifers. Although these effects have impacted water quality, most basins, particularly those with deeper aquifer systems, meet or exceed state and national primary and secondary drinking water standards. Municipalities, academicians, and local water and governmental agencies have studied the stratigraphy of these basins intensely since the early 1900s with the goals of understanding and better managing the important groundwater resource. Lack of a coordinated effort, due in part to jurisdictional issues, combined with the application of lithostratigraphic correlation techniques (based primarily on well cuttings coupled with limited borehole geophysics) have produced an often confusing, and occasionally conflicting

  19. Microbiological risks of recycling urban stormwater via aquifers. (United States)

    Page, D; Gonzalez, D; Dillon, P


    With the release of the Australian Guidelines for Water Recycling: Managed Aquifer Recharge (MAR), aquifers are now being included as a treatment barrier when assessing risk of recycled water systems. A MAR research site recharging urban stormwater in a confined aquifer was used in conjunction with a Quantitative Microbial Risk Assessment to assess the microbial pathogen risk in the recovered water for different end uses. The assessment involved undertaking a detailed assessment of the treatment steps and exposure controls, including the aquifer, to achieve the microbial health-based targets.

  20. A 3-D numerical model of the influence of meanders on groundwater discharge to a gaining stream in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Balbarini, Nicola; Boon, Wietse M.; Nicolajsen, Ellen


    Groundwater discharge to streams depends on stream morphology and groundwater flow direction, but are not always well understood. Here a 3-D groundwater flow model is employed to investigate the impact of meandering stream geometries on groundwater discharge to streams in an unconfined and homoge...