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Ground Water

Muhammad Hasan, Yanjun Shang, Gulraiz Akhter, Majid Khan
The importance of the study of fresh-saline water incursion cannot be over-emphasized. Borehole techniques have been widely used, but they are quite expensive, intrusive, and time consuming. The electrical resistivity method has proved very successful in groundwater assessment. This advanced technique uses the calculation of Dar-Zarrouk (D-Z) parameters, namely longitudinal unit conductance, transverse unit resistance, and longitudinal resistivity has been employed by using 50 vertical electrical sounding points to assess the groundwater and delineate the fresh-saline water interface over 1045 km(2) area of Khanewal in Southern Punjab of Pakistan...
May 12, 2017: Ground Water
Matthew J Knowling, Adrian D Werner
The estimation of recharge through groundwater model calibration is hampered by the nonuniqueness of recharge and aquifer parameter values. It has been shown recently that the estimability of spatially distributed recharge through calibration of steady-state models for practical situations (i.e., real-world, field-scale aquifer settings) is limited by the need for excessive amounts of hydraulic-parameter and groundwater-level data. However, the extent to which temporal recharge variability can be informed through transient model calibration, which involves larger water-level datasets, but requires the additional consideration of storage parameters, is presently unknown for practical situations...
May 12, 2017: Ground Water
Nawal Alfarrah, Gebremedhin Berhane, Abdelrahim Hweesh, Kristine Walraevens
The desert of eastern Libya forms one of the most arid regions of the Sahara. The Great Man-Made River Project (GMRP) was established. It transports millions of cubic meters of water a day from desert wellfields to the coastal cities, where over 80% of the population lives. The Tazerbo Wellfield is one of the wellfields designed within the GMRP, delivering water to the eastern coast of Libya through an underground pipe network. Tazerbo Wellfield consists of 108 production wells; each well was designed to pump 100 L/s...
May 12, 2017: Ground Water
Yun Yang, Jianfeng Wu, Jinguo Wang, Zhifang Zhou
This study presents a new multiobjective evolutionary algorithm (MOEA), the elitist multiobjective tabu search (EMOTS), and incorporates it with MODFLOW/MT3DMS to develop a groundwater simulation-optimization (SO) framework based on modular design for optimal design of groundwater remediation systems using pump-and-treat (PAT) technique. The most notable improvement of EMOTS over the original multiple objective tabu search (MOTS) lies in the elitist strategy, selection strategy, and neighborhood move rule. The elitist strategy is to maintain all nondominated solutions within later search process for better converging to the true Pareto front...
May 10, 2017: Ground Water
Daniel Franco, Kapo Coulibaly, Tanya Kunberger, Kristoph-Dietrich Kinzli, Sebastian Arbelaez, Thomas M Missimer
Mixed carbonate and siliciclastic marine sediments commonly become freshwater aquifers in eastern coastal regions of the United States and many other global locations. As these deposits age, the carbonate fraction of the sediment is commonly removed by dissolution and the aquifer can become a solely siliciclastic system or contain zones or beds of pure quartz sand. During aquifer evolution, the sediment grain size characteristics, hydraulic conductivity, and porosity change. An investigation of these changes using mixed carbonate/siliciclastic sediment samples collected from a modern barrier island beach in southern Florida showed that the average mean grain diameter decreased with removal of the carbonate fraction, but the average hydraulic conductivity and porosity increased slightly, but not to statistical significance...
May 10, 2017: Ground Water
Jean-Philippe Nicot
No abstract text is available yet for this article.
May 10, 2017: Ground Water
Yanmei He
China shares more than 20 transboundary aquifers with its coaquifer states, but they have not exploited their transboundary groundwater resources, and these resources have not been governed by any international agreements. Given the close interaction between surface water and groundwater, and the growing demands for transboundary groundwater in China and its coaquifer states, there is increasing necessity for these countries to undertake international cooperation on this issue. This article overviews China's transboundary aquifers, reviews the duty to cooperate on China's transboundary groundwater as well as the emerging transboundary aquifer law...
May 10, 2017: Ground Water
Rosario Sanchez, Gabriel Eckstein
Totally 36 aquifers have been identified along the Mexico-U.S. border. Of these, only 16 have adequate data to provide a reasonable level of confidence to categorize them as transboundary. Limited and/or contrasting data over the other aquifers in the region reflects the void in transboundary groundwater management and assessment mechanisms throughout much of the Mexico-U.S. border. This paper identifies management mechanisms, structures, and institutional prioritization related to transboundary aquifers shared between Mexico and the United States...
May 10, 2017: Ground Water
Vitaly A Zlotnik, Anvar Kacimov, Ali Al-Maktoumi
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...
May 2, 2017: Ground Water
Shawn M Paquette, Lisa J Molofsky, John A Connor, Kenneth L Walker, Harley Hopkins, Ayan Chakraborty
A suspected increase in the salinity of fresh water resources can trigger a site investigation to identify the source(s) of salinity and the extent of any impacts. These investigations can be complicated by the presence of naturally elevated total dissolved solids or chlorides concentrations, multiple potential sources of salinity, and incomplete data and information on both naturally occurring conditions and the characteristics of potential sources. As a result, data evaluation techniques that are effective at one site may not be effective at another...
April 25, 2017: Ground Water
Munawar Sultana, Taslin Jahan Mou, Santonu Kumar Sanyal, Farzana Diba, Zahid Hayat Mahmud, Anowar Khasru Parvez, M Anwar Hossain
Arsenotrophic bacteria contribute to the nutrient cycling in arsenic (As) affected groundwater. This study employed a culture-independent and -dependent investigation of arsenotrophic microbiomes in As affected groundwater samples collected from Madhabpur, Sonatengra, and Union Porishod in Singair Upazila, Manikganj, Bangladesh. Total As contents, detected by Atomic Absorption Spectrophotometry (AAS) of the samples, were 47 µg/L (Madhabpur, SNGW-1), 53 µg/L (Sonatengra, SNGW-2), and 12 µg/L (Union porishod, SNGW-3), whereas the control well (SNGW-4; depths >150 m) showed As content of 6 µg/L...
April 18, 2017: Ground Water
Colby M Steelman, Jessica R Meyer, Beth L Parker
Organic solvent (i.e., dense nonaqueous phase liquid, DNAPL) migration in the subsurface is known to be extremely sensitive to geologic heterogeneity. There is often a focus on heterogeneity that results from changing depositional conditions over short spatial scales. Similar or even more extreme spatial heterogeneity can result postdeposition due to erosional processes. This study applies a synergistic approach based on a combination of high-resolution lithologic logs of continuous cores, borehole geophysical logs, surface electrical resistivity, and seismic refraction tomography models to assess spatial heterogeneity in a shallow bedrock sequence subject to multiple unconformities and contaminated with a mixture of organic chemicals...
April 12, 2017: Ground Water
Nicholas A Procopio, Thomas B Atherholt, Sandra M Goodrow, Lori A Lester
The influence of precipitation on coliform bacteria detection rates in domestic wells was investigated using data collected through the New Jersey Private Well Testing Act. Measured precipitation data from the National Weather Service (NWS) monitoring stations was compared to estimated data from the Multisensor Precipitation Estimate (MPE) in order to determine which source of data to include in the analyses. A strong concordance existed between these two precipitations datasets; therefore, MPE data was utilized as it is geographically more specific to individual wells...
March 29, 2017: Ground Water
Shih-Jung Wang, Kuo-Chin Hsu, Chein-Lee Wang, Wen-Chi Lai, Liang-Tzu Hsu
The hydraulic properties of aquitards are not easily obtained because monitoring wells are usually installed in aquifers for groundwater resources management. Earthquake-induced crust stress (strain) triggers groundwater level variations over a short period of time in a large area. These groundwater anomalies can be used to investigate aquifer systems. This study uses a poroelastic model to fit the postseismic variations of groundwater level triggered by the Chi-Chi earthquake to evaluate the hydraulic properties of aquitards in the Jhoushuei River alluvial fan (JRAF), Taiwan...
March 23, 2017: Ground Water
Kai Su, Yafeng Zhou, Hegao Wu, Changzheng Shi, Li Zhou
Groundwater inflow estimation is essential for the design and construction of tunnel and the assessment of the environmental impacts. Analytical solutions used in current engineering practice do not adequately account for the effect of the excavation-induced drawdown, which leads to significant change in pore water pressure distribution and reductions of the water level beyond tunnel. Based on the numerical analysis results, this article proposes semianalytical method to predict the height of lowered water level and groundwater tunnel inflow...
March 22, 2017: Ground Water
Sarah A Vitale, Gary A Robbins
Determination of vertical flow rates in a fractured bedrock well can aid in planning and implementing hydraulic tests, water quality sampling, and improving interpretations of water quality data. Although flowmeters are highly accurate in flow rate measurement, the high cost and logistics may be limiting. In this study the dissolved oxygen alteration method (DOAM) is expanded upon as a low-cost alternative to determine vertical flow rates in crystalline bedrock wells. The method entails altering the dissolved oxygen content in the wellbore through bubbler aeration, and monitoring the vertical advective movement of the dissolved oxygen over time...
March 22, 2017: Ground Water
Xin Luo, King Lun Kwok, Yi Liu, Jimmy Jiao
To study the spatial and temporal variability of water dynamics and chemical reactions within the coastal groundwater mixing zones (CGMZs), high-resolution periodical and spatial groundwater sampling within CGMZs is needed. However, current samplers and sampling systems may require heavy driving machines to install. There is also possible contamination from the metal materials for current samplers and sampling systems. Here, a permanent multilevel sampling system is designed to sample coastal groundwater within CGMZs...
March 15, 2017: Ground Water
Pin Shuai, Peter S K Knappett, Saddam Hossain, Alamgir Hosain, Kimberly Rhodes, Kazi Matin Ahmed, M Bayani Cardenas
Oceanic tidal fluctuations which propagate long distances up coastal rivers can be exploited to constrain hydraulic properties of riverbank aquifers. These estimates, however, may be sensitive to degree of aquifer confinement and aquifer anisotropy. We analyzed the hydraulic properties of a tidally influenced aquifer along the Meghna River in Bangladesh using: (1) slug tests combined with drilling logs and surface resistivity to estimate Transmissivity (T); (2) a pumping test to estimate T and Storativity (S) and thus Aquifer Diffusivity (DPT ); and (3) the observed reduction in the amplitude and velocity of a tidal pulse to calculate D using the Jacob-Ferris analytical solution...
March 8, 2017: Ground Water
Jean-Philippe Nicot, Toti Larson, Roxana Darvari, Patrick Mickler, Kristine Uhlman, Ruth Costley
Assessing natural vs. anthropogenic sources of methane in drinking water aquifers is a critical issue in areas of shale oil and gas production. The objective of this study was to determine controls on methane occurrences in aquifers in the Eagle Ford Shale play footprint. A total of 110 water wells were tested for dissolved light alkanes, isotopes of methane, and major ions, mostly in the eastern section of the play. Multiple aquifers were sampled with approximately 47 samples from the Carrizo-Wilcox Aquifer (250-1200 m depth range) and Queen City-Sparta Aquifer (150-900 m depth range) and 63 samples from other shallow aquifers but mostly from the Catahoula Formation (depth <150 m)...
March 2, 2017: Ground Water
Jean-Philippe Nicot, Patrick Mickler, Toti Larson, M Clara Castro, Roxana Darvari, Kristine Uhlman, Ruth Costley
Clusters of elevated methane concentrations in aquifers overlying the Barnett Shale play have been the focus of recent national attention as they relate to impacts of hydraulic fracturing. The objective of this study was to assess the spatial extent of high dissolved methane previously observed on the western edge of the play (Parker County) and to evaluate its most likely source. A total of 509 well water samples from 12 counties (14,500 km(2) ) were analyzed for methane, major ions, and carbon isotopes. Most samples were collected from the regional Trinity Aquifer and show only low levels of dissolved methane (85% of 457 unique locations <0...
March 1, 2017: Ground Water
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