Surface Water Inputs Research Articles

Using hydrogeophysical methods to assess the feasibility of lake bank filtration

Lake Tissø is the fourth largest lake in Denmark with sufficient, continuous surface water input making lake bank filtration an optimal surface water extraction method provided that there are suitable shallow aquifers with a good hydraulic connection to the lake. The shallow subsurface under the lake was mapped by five waterborne Electrical Resistivity Tomography (ERT) and eight Ground Penetrating Radar (GPR) surveys to locate potentially suitable aquifers. Distributed Temperature Sensing (DTS) was used for the general characterisation of the hydraulic connection between the lake and aquifer. The waterborne ERT surveys showed several zones of coarser material along the shore extending up to five meters depth below the lake surface, while on-land ERT surveys confirmed that these zones extend to the lakeshore with similar thickness. Both waterborne ERT and GPR profiles agreed that at a selected field site the highest possibility of coarse sediments is 60–140 m from the lakeshore. Lakebed temperatures measured in December 2016, May and June 2017 all indicated potential groundwater discharge to the lake at approximately 135 m from the shoreline supporting the results of geophysical surveys showing coarser sediments in that area. A 2D numerical flow model of the area with a geological setup based on geophysical information and slugtest data, also showed upward groundwater discharge peaks at 60 and 140 m from the shoreline confirming the findings of the field surveys. Thus, this study shows that the combination of waterborne ERT and GPR surveys with DTS measurements is a fast and efficient way to assess the feasibility of lake bank filtration in these settings. This approach of combined hydrogeophysical methods is robust and has a potential to site lake bank filtration areas not only next to large rivers where coarse sediments are found in abundance, but even in different sedimentary environments where suitable layers for lake bank filtration are more difficult to identify.

Composition of pelagic microbial communities in Mediterranean coastal aquatic ecosystems under extreme drought conditions

Mediterranean coastal aquatic ecosystems are heterogeneous systems covering a wide range of hydrological characteristics. Differences in the hydrological pattern determine the nutrient dynamics and microbial community composition of these habitats. We analysed the composition of the microbial community composition and the factors affecting the predominance of autotrophic (A) or heterotrophic (H) microorganisms in 17 coastal water bodies of the Empordà and Baix Ter wetlands (NE Iberian Peninsula) during mid-summer under severe drought conditions. We sampled three types of water bodies with differences in their water residence time: 6 isolated euhaline basins, 8 oligohaline basins and the estuaries of the three rivers that flood into the area. Our aim was to determine if differences exist in the microbial community structure in Mediterranean coastal water bodies with different residence time under conditions of severe drought or, on the other hand, if the lack of flooding during the summer makes isolated, choked and leaky ecosystems more similar. Isolated basins showed higher values than estuaries for temperature, conductivity and the proportion of nutrients in organic forms. Regarding microbial community composition, microphytoplankton (mainly dinoflagellates) dominated in isolated lagoons, while picoplankton dominated in estuaries. We found no significant differences between oligohaline basins and both estuaries and isolated basins for either physical and chemical variables or microbial community composition. Only the proportion between autotrophic and heterotrophic organisms was lower in oligohaline basins than in isolated ones. We conclude that the estuaries of rivers with measurable flow during the summer differ from lagoons long isolated from any surface water input; similarities that we expected to find between leaky and isolated ecosystems under drought conditions arise in only oligohaline waters with intermediate residence times.

Managing Surface Water Inputs to Reduce Phosphorus Loss from Cranberry Farms.

Cranberry ( Ait.) production in Massachusetts represents one-fourth of the US cranberry supply, but water quality concerns, water use, and wetland protection laws challenge the future viability of the state's cranberry industry. Pond water used for harvest and winter flooding accounts for up to two-thirds of phosphorus (P) losses in drainage waters. Consequently, use of P sorbing salts to treat pond water holds promise in the mitigation of P losses from cranberry farms. Laboratory evaluation of aluminum (Al)-, iron (Fe)-, and calcium (Ca)-based salts was conducted to determine the application rate required for reducing P in shallow (0.4 m) and deep (3.2 m) water ponds used for cranberry production. Limited P removal (<22%) with calcium carbonate and calcium sulfate was consistent with their relatively low solubility in water. Calcium hydroxide reduced total P up to 49%, but increases in pond water pH (>8) could be detrimental to cranberry production. Ferric sulfate and aluminum sulfate applications of 15 mg L (ppm) resulted in near-complete removal of total P, which decreased from 49 ± 3 to <10 μg P L (ppb). However, ferric sulfate application lowered pH below the recommend range for cranberry soils. Field testing of aluminum sulfate demonstrated that at a dose of 15 mg L (∼1.4 Al mg L), total P in pond water was reduced by 78 to 94%. Laboratory and field experiments support the recommendation of aluminum sulfate as a cost-effective remedial strategy for reducing elevated P in surface water used for cranberry production.

Geochemical and isotopic evidences from groundwater and surface water for understanding of natural contamination in chronic kidney disease of unknown etiology (CKDu) endemic zones in Sri Lanka

ABSTRACTChronic kidney disease of unknown etiology (CKDu) is the main health issue in the dry zone of Sri Lanka. Despite many studies carried out, causative factors have not been identified yet clearly. According to the multidisciplinary researches carried out so far, potable water is considered as the main causative factor for CKDu. Hence, the present study was carried out with combined isotopic and chemical methods to understand possible relationships between groundwater; the main drinking water source, and CKDu in four endemic areas in the dry zone. Different water sources were evaluated isotopically (2H, 3H and 18O) and chemically from 2013 to 2015. Results revealed that prevalence of CKDu is significantly low with the groundwater replenished by surface water inputs. It is significantly high with the groundwater stagnated as well as groundwater recharged from regional flow paths. Thus, the origin, recharge mechanism and flow pattern of groundwater, as well as geological conditions which would be responsible for natural contamination of groundwater appear as the main causative factors for CKDu. Therefore, detailed investigations should be made in order to identify the element(s) in groundwater contributing to CKDu. The study recommends providing drinking water to the affected zones using water sources associated with surface waters.

Inputs and Internal Cycling of Nitrogen to a Causeway Influenced, Hypersaline Lake, Great Salt Lake, Utah, USA

Nitrogen inputs to Great Salt Lake (GSL), located in the western USA, were quantified relative to the resident nitrogen mass in order to better determine numeric nutrient criteria that may be considered at some point in the future. Total dissolved nitrogen inputs from four surface-water sources entering GSL were modeled during the 5-year study period (2010–2014) and ranged from 1.90 × 106 to 5.56 × 106 kg/year. The railroad causeway breach was a significant conduit for the export of dissolved nitrogen from Gilbert to Gunnison Bay, and in 2011 and 2012, net losses of total nitrogen mass from Gilbert Bay via the Causeway breach were 9.59 × 105 and 1.51 × 106 kg. Atmospheric deposition (wet + dry) was a significant source of nitrogen to Gilbert Bay, exceeding the dissolved nitrogen load contributed via the Farmington Bay causeway surface-water input by >100,000 kg during 2 years of the study. Closure of two railroad causeway culverts in 2012 and 2013 likely initiated a decreasing trend in the volume of the higher density Deep Brine Layer and associated declines in total dissolved nitrogen mass contained in this layer. The large dissolved nitrogen pool in Gilbert Bay relative to the amount of nitrogen contributed by surface-water inflow sources is consistent with the terminal nature of GSL and the predominance of internal nutrient cycling. The opening of the new railroad causeway breach in 2016 will likely facilitate more efficient bidirectional flow between Gilbert and Gunnison Bays, resulting in potentially substantial changes in nutrient pools within GSL.

Thermal groundwater contributions of arsenic and other trace elements to the middle Provo River, Utah, USA

Groundwater inputs can impact river water quality but are difficult to disentangle from agricultural, urban, and storm runoff. To better understand the multiple processes affecting water quality, we used major solute and trace element concentrations with continuous measurements of flow rates and specific conductance to track temporal and spatial changes in surface water and groundwater solute inputs into the middle Provo River, located in northern Utah, USA. Thermal groundwater was the most important source of major solutes and trace elements to the middle Provo River, with concentrations of As, B, Cs, Li, Sr, and Rb increasing dramatically (twofold to tenfold) downstream of thermal water inputs in the Snake Creek tributary. Snake Creek accounted for only 20% of the flow to the Provo River but increased the As concentrations ~four-fold. Diffuse groundwater inputs, including thermal water, along the Provo River also contributed a measureable increase in solute concentrations. Mixing calculations indicate that groundwater contributed up to 10% of the total streamflow to the middle Provo River, causing an increase in thermal groundwater-derived trace element concentrations. In addition to natural groundwater inputs, water quality was impacted by anthropogenic trace and major element inputs from surface water tributaries. Nitrate, Ba, and V concentrations increased substantially downstream of agricultural/urban inputs. Specific conductance data showed that tributaries added solutes to the Provo River during runoff events, likely from the washoff of road salts. With evidence of both natural and anthropogenic inputs of trace and major elements to the middle Provo River, our study has implications for understanding water quality in complex coupled human–natural systems and demonstrates the influence of thermal groundwater inputs on water quality where such systems discharge.

Surge dynamics and lake outbursts of Kyagar Glacier, Karakoram

Abstract. The recent surge cycle of Kyagar Glacier, in the Chinese Karakoram, caused formation of an ice-dammed lake and subsequent glacial lake outburst floods (GLOFs) exceeding 40 million m3 in 2015 and 2016. GLOFs from Kyagar Glacier reached double this size in 2002 and earlier, but the role of glacier surging in GLOF formation was previously unrecognised. We present an integrative analysis of the glacier surge dynamics from 2011 to 2016, assessing surge mechanisms and evaluating the surge cycle impact on GLOFs. Over 80 glacier surface velocity fields were created from TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement), Sentinel-1A, and Landsat satellite data. Changes in ice thickness distribution were revealed by a time series of TanDEM-X elevation models. The analysis shows that, during a quiescence phase lasting at least 14 years, ice mass built up in a reservoir area at the top of the glacier tongue, and the terminus thinned by up to 100 m, but in the 2 years preceding the surge onset this pattern reversed. The surge initiated with the onset of the 2014 melt season, and in the following 15 months velocity evolved in a manner consistent with a hydrologically controlled surge mechanism. Dramatic accelerations coincided with melt seasons, winter deceleration was accompanied by subglacial drainage, and rapid surge termination occurred following the 2015 GLOF. Rapid basal motion during the surge is seemingly controlled by high water pressure, caused by input of surface water into either an inefficient subglacial drainage system or unstable subglacial till. The potential lake volume increased to more than 70 million m3 by late 2016, as a result of over 60 m of thickening at the terminus. Lake formation and the evolution of the ice dam height should be carefully monitored through remote sensing to anticipate large GLOFs in the near future.

Investigação da atividade estrogênica em águas subterrâneas do Estado de São Paulo

Os interferentes endócrinos são substâncias químicas de diversas naturezas como hormônios naturais (estrona - E1, estradiol - E2, estriol - E3), hormônios sintéticos (etinilestradiol - EE2, utilizado em anticoncepcionais), compostos orgânicos sintéticos como o bisfenol A, praguicidas organoclorados como o DDT, entre outros, capazes de interferir na ação dos hormônios. Com o atual quadro de demanda hídrica no Estado de São Paulo e consequente aumento da exploração de água subterrânea, o potencial de infiltração de água superficial contaminada por interferentes endócrinos na água subterrânea tem aumentado devido ao rebaixamento do lençol, especialmente nos locais onde poços de alta vazão estão localizados próximos às águas superficiais. As redes de esgotos danificadas e sistemas sépticos podem também levar a lixiviação desses compostos para as águas subterrâneas. Com objetivo de investigar a atividade estrogênica em águas subterrâneas do Estado de São Paulo, a CETESB utilizou no presente estudo o bioensaio BLYES (Bioluminescent Yeast Estrogen Screen), baseado em leveduras bioluminescentes, no período de 2011 a 2015. Dos 78 pontos de coleta da rede de monitoramento, 6 apresentaram atividade estrogênica superior ao limite de quantificação do método, entretanto, os valores ficaram abaixo do valor de referência de 3,8 ng E2 eq L-1, evidenciando que não há risco à saúde humana para consumo de água subterrânea a longo prazo. Os resultados mostram que as águas subterrâneas analisadas estão protegidas quanto à ocorrência de atividade estrogênica.

Petrological, geochemical and isotopic characteristics of the Collo ultramafic rocks (NE Algeria)

The ultramafic rocks of the Collo region in northeastern Algeria crop out as “stratified” masses that cut across older metamorphic formations of the Petite Kabylie basement. Based on petrological compositions and mineralogical observations, these rocks are mainly peridotites and serpentinites. The peridotites are identified as lherzolites, but dunites may occur rarely. The lherzolites are composed of olivine, orthopyroxene, clinopyroxene and chromian spinel. Their chemical composition shows high MgO (34.4–37.5 wt%), Cr (0.14–0.27 wt%), Ni (0.14–0.26 wt%) and Co (34–133 ppm) contents and low CaO and Al2O3 concentrations (0.02–2.2 wt% and 0.5 to 2.8 wt%, respectively). The chromite, which represents approximately 1–3% of the rock, is ubiquitous and shows two different generations: primary millimetric euhedral crystals and secondary fine xenomorphic grains and interstitial aggregates. The primary chromites are alumino-ferro-magnesian crystals that show high Al2O3 (25.77%–27.36%) and MgO (10.70%–13.36%). Cr# (100 × Cr/(Al + Cr)) ranges from 45 to 48, and Mg# (100 × Mg/(Mg + Fe2+)) from 49 to 59. The secondary interstitial grains are iron-rich chromites. They show low Al2O3 (4.67%–9.54%) and MgO (4.60%–4.65%). Cr# is relatively high (77–88), whereas Mg# shows relatively low values, ranging from 22 to 25. Primary chromite and whole-rock chemistry show that the Collo ultramafic rocks belong to Alpine-type peridotites that were emplaced within an orogenic setting. The oxygen isotopic composition of both peridotites and chromites is consistent with their derivation from a mantle source (δ18O ranges from +3.0 to +5.9‰). Low δ18O values (<+4.4‰) are recorded in serpentinites and are attributed to the effect of serpentinization processes through high-temperature metasomatic fluids. Magnesite-bearing serpentinites show the lowest δ18O values. These are interpreted as the result of surface water input.

Long-term (11 years) study of water balance, flushing times and water chemistry of a coastal wetland undergoing restoration, Everglades, Florida, USA

Upstream water diversions have significantly reduced freshwater flow to coastal wetlands of the Everglades. The purpose of this research was to investigate the water balance, flushing time, and water chemistry of Taylor Slough; one of the main natural waterways of the coastal Everglades, during its early stages of restoration. Both the water balance and flushing times were calculated on a monthly basis from 2001 to 2011. Surface water chemistry was analyzed using 3-day composite samples collected every 18h. Current restoration efforts have been able to increase surface water inputs to southern Taylor Slough, but rainfall was still the dominant water input. Flushing times varied between 3 and 78days, with the highest values occurring in December and the lowest in May. Flushing times were negatively correlated with evapotranspiration (ET), but were longer when surface water volume exceeded ET and shorter when ET exceeded water volume. Surface water concentrations of calcium and chloride along with total nitrogen and total phosphorus were negatively correlated with flushing times. The results herein suggest that in coastal wetlands with low quantities of surface water inputs, ET and surface water volume influenced by rainfall are the most dominant factors influencing flushing times and water chemistry. Increased surface water inflows with additional restoration efforts would be expected to increase surface water volumes into southern Taylor Slough, thereby increasing flushing times and decreasing ion and nutrient concentrations.

Does habitat restoration enhance spring biodiversity and ecosystem functions?

Degradation of groundwater-dependent ecosystems has raised a need for their restoration, but ecological responses to restoration are largely unknown. We evaluated the effectiveness of spring restoration using data from near-natural, restored, and human-impacted springs, the major impact being degradation of spring hydrology by forest drainage. We used both taxonomic (bryophytes, macroinvertebrates, and leaf-decomposing fungi) and functional (leaf breakdown) measures of restoration success. We expected that by reducing surface water input, restoration will improve spring hydrology and place spring ecosystems in a trajectory towards more natural conditions. Restored springs were thermally more stable than impacted springs and the contribution of surface water was greatly reduced. Bryophytes were more abundant in restored than in impacted springs but did not differ among restored and natural springs. Similarly, macroinvertebrate communities differed between restored and impacted springs whereas no difference was detected between restored and natural sites. Species diversity and functional attributes showed weaker responses to restoration. Our results suggest that restoration enhances spring habitat quality, and the first signs of biodiversity enhancement were also detectable only a few years post-restoration. Restoration clearly bears great promise as a conservation tool for the protection of this valuable component of regional freshwater biodiversity.

Surface water input from snowmelt and rain throughfall in western juniper: potential impacts of climate change and shifts in semi‐arid vegetation

AbstractIn the western USA, shifts from snow to rain precipitation regimes and increases in western juniper cover in shrub‐dominated landscapes can alter surface water input via changes in snowmelt and throughfall. To better understand how shifts in both precipitation and semi‐arid vegetation cover alter above‐ground hydrological processes, we assessed how rain interception differs between snow and rain surface water input; how western juniper alters snowpack dynamics; and how these above‐ground processes differ across western juniper, mountain big sagebrush and low sagebrush plant communities. We collected continuous surface water input with four large lysimeters, interspace and below‐canopy snow depth data and conducted periodic snow surveys for two consecutive water years (2013 and 2014). The ratio of interspace to below‐canopy surface water input was greater for snow relative to rain events, averaging 79.4% and 54.8%, respectively. The greater surface water input ratio for snow is in part due to increased deposition of redistributed snow under the canopy. We simulated above‐ground energy and water fluxes in western juniper, low sagebrush and mountain big sagebrush for two 8‐year periods under current and projected mid‐21st century warmer temperatures with the Simultaneous Heat and Water (SHAW) model. Juniper compared with low and mountain sagebrush reduced surface water input by an average of 138 mm or 24% of the total site water budget. Conversely, warming temperatures reduced surface water input by only an average of 14 mm across the three vegetation types. The future (warmer) simulations resulted in earlier snow disappearance and surface water input by 51 and 45 days, respectively, across juniper, low sagebrush and mountain sagebrush. Information from this study can help land managers in the sagebrush steppe understand how both shifts in climate and semi‐arid vegetation will alter fundamental hydrological processes. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Isotope and hydrochemistry reveal evolutionary processes of lake water in Qinghai Lake

Abstract Qinghai Lake is the largest lake in China and is one of more than 500 brackish lakes on the Tibet Plateau. This study investigated stable isotopes (δ 18 O and δ 2 H) and hydrochemistry of lake water in Qinghai Lake and surrounding lakes to understand the lakes' evolutionary processes. These processes help explain the formation and evolution of the brackish and salt lakes on the Tibetan Plateau. The original isotopic and chemical compositions of lake water were controlled by a mixture of water from river water, groundwater, and precipitation. The values of δ 18 O and δ 2 H of most of the lake water samples were greater than zero due to continuous strong evaporation. The cations were in the order Na + > Mg 2 + > K + > Ca 2 + , and anions were in the order Cl − > SO 4 2 − > HCO 3 − . The hydrochemical types of Qinghai Lake and surrounding lakes were Na + -Cl − . The lake water, excluding Erhai Lake, was saturated with CaCO 3 . There was significant aragonite precipitation, and the Ca 2 + concentration was relatively low. Haiyanwan Lake and Gahai Lake, which have no surface water inputs, had experienced stronger evaporation than Qinghai Lake since the lakes were isolated from Qinghai Lake due to the dropping lake level and the arid climate. Erhai Lake water had relatively low salinity due to the fresh water coming in from the Daotang River. With the continued strong evaporation of lake water, Qinghai Lake and surrounding lakes should become increasingly saline. However, the salinity of lakes on the Tibetan Plateau is likely to slowly decrease in future decades due to the increasing precipitation and runoff, which will dilute lake water. In the longer term, however, Qinghai Lake and the brackish lakes will likely still become more saline, given the continued contribution of chemical ions from river water and groundwater and strong evaporation from the lake surface.

Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts

Abstract. Degradation of coastal ecosystems by eutrophication is largely defined by nitrogen loading from land via surface water and groundwater flows. However, indicators of water quality are highly variable due to a myriad of other drivers, including temperature and precipitation. To evaluate these drivers, we examined spatial and temporal trends in a 22-year record of summer water quality data from 122 stations in 17 embayments within Buzzards Bay, MA (USA), collected through a citizen science monitoring program managed by Buzzards Bay Coalition. To identify spatial patterns across Buzzards Bay's embayments, we used a principle component and factor analysis and found that rotated factor loadings indicated little correlation between inorganic nutrients and organic matter or chlorophyll a (Chl a) concentration. Factor scores showed that embayment geomorphology in addition to nutrient loading was a strong driver of water quality, where embayments with surface water inputs showed larger biological impacts than embayments dominated by groundwater influx. A linear regression analysis of annual summertime water quality indicators over time revealed that from 1992 to 2013, most embayments (15 of 17) exhibited an increase in temperature (mean rate of 0.082 ± 0.025 (SD) °C yr−1) and Chl a (mean rate of 0.0171 ± 0.0088 log10 (Chl a; mg m−3) yr−1, equivalent to a 4.0 % increase per year). However, only seven embayments exhibited an increase in total nitrogen (TN) concentration (mean rate 0.32 ± 0.47 (SD) µM yr−1). Average summertime log10(TN) and log10(Chl a) were correlated with an indication that the yield of Chl a per unit total nitrogen increased with time suggesting the estuarine response to TN may have changed because of other stressors such as warming, altered precipitation patterns, or changing light levels. These findings affirm that nitrogen loading and physical aspects of embayments are essential in explaining the observed ecosystem response. However, climate-related stressors may also need to be considered by managers because increased temperature and precipitation may worsen water quality and partially offset benefits achieved by reducing nitrogen loading.

Stream Nitrogen Inputs Reflect Groundwater Across a Snowmelt-Dominated Montane to Urban Watershed.

Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream water isotopes (δ(2)H and δ(18)O) reflected a consistent snowmelt water source during baseflow. Near-chemostatic relationships between conservative ions and discharge implied that groundwater dominated discharge year-round across the montane and urban sites, challenging the conceptual emphasis on direct stormwater inputs to urban streams. Stream and groundwater NO3(-) concentrations remained consistently low during snowmelt and baseflow in most montane and urban stream reaches, indicating effective subsurface N retention or denitrification and minimal impact of fertilizer or deposition N sources. Rather, NO3(-) concentrations increased 50-fold following urban groundwater inputs, showing that subsurface flow paths potentially impact nutrient loading more than surficial land use. Isotopic composition of H2O and NO3(-) suggested that snowmelt-derived urban groundwater intercepted NO3(-) from leaking sewers. Sewer maintenance could potentially mitigate hotspots of stream N inputs at mountain/valley transitions, which have been largely overlooked in semiarid urban ecosystems.

Groundwater Isolation Governs Chemistry and Microbial Community Structure along Hydrologic Flowpaths.

This study deals with the effects of hydrodynamic functioning of hard-rock aquifers on microbial communities. In hard-rock aquifers, the heterogeneous hydrologic circulation strongly constrains groundwater residence time, hydrochemistry, and nutrient supply. Here, residence time and a wide range of environmental factors were used to test the influence of groundwater circulation on active microbial community composition, assessed by high throughput sequencing of 16S rRNA. Groundwater of different ages was sampled along hydrogeologic paths or loops, in three contrasting hard-rock aquifers in Brittany (France). Microbial community composition was driven by groundwater residence time and hydrogeologic loop position. In recent groundwater, in the upper section of the aquifers or in their recharge zone, surface water inputs caused high nitrate concentration and the predominance of putative denitrifiers. Although denitrification does not seem to fully decrease nitrate concentrations due to low dissolved organic carbon concentrations, nitrate input has a major effect on microbial communities. The occurrence of taxa possibly associated with the application of organic fertilizers was also noticed. In ancient isolated groundwater, an ecosystem based on Fe(II)/Fe(III) and S/SO4 redox cycling was observed down to several 100 of meters below the surface. In this depth section, microbial communities were dominated by iron oxidizing bacteria belonging to Gallionellaceae. The latter were associated to old groundwater with high Fe concentrations mixed to a small but not null percentage of recent groundwater inducing oxygen concentrations below 2.5 mg/L. These two types of microbial community were observed in the three sites, independently of site geology and aquifer geometry, indicating hydrogeologic circulation exercises a major control on microbial communities.

OPTIMAL OPERATION OF MULTIPURPOSE RESERVOIR FOR IRRIGATION PLANNING WITH CONJUNCTIVE USE OF SURFACE AND GROUNDWATER USING FUZZY RESOURCES

A Fuzzy Linear programming (FLP) model has been developed with the objective of maximizing the net benefits accrued from crops in a year and subjected to constraints on availability of surface water, groundwater, culturable area, and other inputs such as reservoir storages, water requirement of crops, canal capacity and reservoir continuity. It is a conjunctive use model of surface water and ground water to obtain the optimal operating policy for a multipurpose single reservoir by considering the fuzziness involved in the resources i.e. availability of surface water, groundwater and the culturable area. The linear membership function is developed to fuzzify the resources. The developed model is applied to the case study of Jayakwadi reservoir stage-I, built across the river Godavari, Maharashtra state, India. The final model is solved for the maximized degree of satisfaction (λ). The λ obtained is equal to 0.51 and corresponding values of the objective is 3438.439 million rupees.

Integration of an energy balance snowmelt model into an open source modeling framework

This paper presents a data model for organizing the inputs and outputs of an energy balance snowmelt model (the Utah Energy Balance Model, UEB) that provides a foundation for its integration into the EPA BASINS modeling framework and enables its coupling with other hydrologic models in this system. Having UEB as a BASINS component has facilitated its coupling with the Geospatial Streamflow Forecast Model (GeoSFM) to compute the melting of glaciers and subsequent streamflow in the Himalayas. The data model uses a combination of structured text and network Common Data Form (netCDF) files to represent parameters, geographical, time series, and gridded space-time data. We describe the design and structure of this data model, integration methodology of UEB and GeoSFM and illustrate the effectiveness of the resulting coupled models for the computation of surface water input and streamflow for a glaciated watershed in Nepal Himalayas.

Water Purification in Artificial Wetlands from Livestock and Farmland Wastewater

Volume 3 • Issue 3 • 1000e113 J Pollut Eff Cont ISSN:2375-4397 JPE, an open access journal The end-point treatment of point pollution sources is the best way to improve the quality of water and prevent pollution, all over the world. Nevertheless, non-point pollution sources that influence the quality of surface water are serious concerns. Wetlands receive surface water inputs from streams, surface runoff, precipitation, and overland flow and subsurface water inputs from surface infiltration, stream hyporheic zones, and ground water. In this study water source includes effluent from livestock farms and domestic wastewater. By monitoring and analyzing the variations in the water quality, the removal efficiency in different ponds of the artificial wetland for various pollution sources can be obtained. Factor analysis and cluster analysis are adopted to describe the spatial characteristics of the data and seasonal variations in the water quality respectively.

Will water scarcity in semiarid regions limit hydraulic fracturing of shale plays?

There is increasing concern about water constraints limiting oil and gas production using hydraulic fracturing (HF) in shale plays, particularly in semiarid regions and during droughts. Here we evaluate HF vulnerability by comparing HF water demand with supply in the semiarid Texas Eagle Ford play, the largest shale oil producer globally. Current HF water demand (18 billion gallons, bgal; 68 billion liters, bL in 2013) equates to ∼16% of total water consumption in the play area. Projected HF water demand of ∼330 bgal with ∼62 000 additional wells over the next 20 years equates to ∼10% of historic groundwater depletion from regional irrigation. Estimated potential freshwater supplies include ∼1000 bgal over 20 yr from recharge and ∼10 000 bgal from aquifer storage, with land-owner lease agreements often stipulating purchase of freshwater. However, pumpage has resulted in excessive drawdown locally with estimated declines of ∼100–200 ft in ∼6% of the western play area since HF began in 2009–2013. Non-freshwater sources include initial flowback water, which is ≤5% of HF water demand, limiting reuse/recycling. Operators report shifting to brackish groundwater with estimated groundwater storage of 80 000 bgal. Comparison with other semiarid plays indicates increasing brackish groundwater and produced water use in the Permian Basin and large surface water inputs from the Missouri River in the Bakken play. The variety of water sources in semiarid regions, with projected HF water demand representing ∼3% of fresh and ∼1% of brackish water storage in the Eagle Ford footprint indicates that, with appropriate management, water availability should not physically limit future shale energy production.