Read by QxMD icon Read

Ground Water

Muhammad Hasan, Yanjun Shang, Gulraiz Akhter, Weijun Jin
An integrated study using geophysical method in combination with pumping tests and geochemical method was carried out to delineate groundwater potential zones in Mian Channu area of Pakistan. Vertical electrical soundings (VES) using Schlumberger configuration with maximum current electrode spacing (AB/2 = 200 m) were conducted at 50 stations and 10 pumping tests at borehole sites were performed in close proximity to 10 of the VES stations. The aim of this study is to establish a correlation between the hydraulic parameters obtained from geophysical method and pumping tests so that the aquifer potential can be estimated from the geoelectrical surface measurements where no pumping tests exist...
November 17, 2017: Ground Water
Dylan J Irvine
No abstract text is available yet for this article.
November 16, 2017: Ground Water
Yizhi Sheng, Guangcai Wang, Dan Zhao, Chunbo Hao, Chenglong Liu, Linfeng Cui, Ge Zhang
Spatial distribution (horizonal and vertical) of groundwater microbial communities and the hydrogeochemistry in confined aquifers were studied approximately along the groundwater flow path from coteau to plain in the Nomhon area, Qinghai-Tibet plateau, China. The confined groundwater samples at different depths and locations were collected in three boreholes through a hydrogeological section in this arid and semi-arid area. The phylogenetic analysis of 16S rRNA genes and multivariate statistical analysis were used to elucidate similarities and differences between groundwater microbial communities and hydrogeochemical properties...
November 9, 2017: Ground Water
Xun Zhou, Xiaocui Wang, Jiajun Han, Qin Cao, Changlong Jiang, Juan Guo, Haiyan Zhou
Subsurface K-rich brines are important mineral resources for fertilizer production while the evolution of such brines is poorly documented. In the Sichuan Basin in southwest China, they are found mainly in the Middle and Lower Triassic marine carbonate aquifers. Total dissolved solids of the brines range from 176 to 378 g/L and K concentrations, from 1.9 to 53.3 g/L. We found that the brines are mainly of Cl-Na type, while Ba is absent in the brines. Comparison of the brine samples with both the trajectories of ions and the newly proposed trajectories of ion ratios of evaporated seawater suggests that the brines are enriched in Ca, Sr, Li, and I, depleted in SO4 and Mg, and neither enriched nor depleted in Cl and Na...
November 9, 2017: Ground Water
David Deming
No abstract text is available yet for this article.
November 9, 2017: Ground Water
Randal J Barnes
When is the impact of a sloping base large enough to justify more complex models for an unconfined aquifer? The intuitive answer that "it depends on the magnitude of the slope" is not wholly correct. Using recent mathematical results (the Lambert W function), we explicitly solve the simple sloping base problem. This explicit solution offers insights beyond those possible using Dupuit's, Polubarinov-Kochina's, Harr's, Child's, and others' implicit solutions. Specifically, it shows that the impact of the sloping base is best characterized by the saturated thickness divided by the change in base elevation, not by the slope...
November 9, 2017: Ground Water
Venkataramana Sridhar, Mirza M Billah, John W Hildreth
Many current watershed modeling efforts now incorporate surface water and groundwater for managing water resources since the exchanges between groundwater and surface water need a special focus considering the changing climate. The influence of groundwater dynamics on water and energy balance components is investigated in the Snake River Basin (SRB) by coupling the Variable Infiltration Capacity (VIC) and MODFLOW models (VIC-MF) for the period of 1986 through 2042. A 4.4% increase in base flows and a 10.3% decrease in peak flows are estimated by VIC-MF compared to the VIC model in SRB...
November 9, 2017: Ground Water
Nengfang Chao, Zhicai Luo, Zhengtao Wang, Taoyong Jin
Quantitative estimates of the groundwater depletion and droughts in the Tigris-Euphrates Basin (TEB) can be useful for sustainably managing its water resources. Here, data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are used to infer the monthly changes in the total water storage of the TEB from January 2003 to December 2015. Additionally, the data of altimetry and output from land surface models are used to remove the contributions from lake water changes and other hydrological factors to obtain the total groundwater depletion (TGWD), human-driven groundwater depletion (HGWD), and climate-driven groundwater depletion...
October 31, 2017: Ground Water
Roxana Darvari, Jean-Philippe Nicot, Bridget R Scanlon, Patrick Mickler, Kristine Uhlman
There is concern about adverse impacts of natural gas (primarily methane) production on groundwater quality; however, data on trace element concentrations are limited. The objective of this study was to compare the distribution of trace elements in groundwater samples with and without dissolved methane in aquifers overlying the Barnett Shale (Hood and Parker counties, 207 samples) and the Haynesville Shale (Panola County, 42 samples). Both shales have been subjected to intensive hydraulic fracturing for gas production...
October 30, 2017: Ground Water
Daoyong Wu, Xiangyang Zhou, Xingyuan Jiang
Water and salt transfer coupled with phase change may cause serious damage to engineering structures in saline soil regions. In this study, the migration of water and salt in silty clay collected from the Qinghai-Tibet Plateau is explored experimentally and numerically during freezing and thawing processes. The results revealed that there are significant differences in the variations of liquid water content and solution concentration for different initial salt contents, due to salt crystallization and dissolution...
October 17, 2017: Ground Water
Hiroaki Abe, Changyuan Tang, Nozomu Takeuchi, Akihiko Kondoh
Intensive groundwater development in the urban area of the Nagaoka Plain, Japan, has induced changes in the pH and saturation index of calcite in groundwater. To account for these chemical changes, it is important to determine seasonal variations of recharge and the groundwater flow system in the aquifer. This study identified the sources and flow system of groundwater in this urban area by a comprehensive method using stable isotope data and a numerical groundwater model of the Nagaoka Plain. Stable isotope evidence shows that the groundwater is recharged by meteoric water originating from low-elevation areas rather than the mountains surrounding the plain...
October 17, 2017: Ground Water
Remi Valois, Yohann Cousquer, Myriam Schmutz, Alexandre Pryet, Célestine Delbart, Alain Dupuy
Characterizing the interactions between streams and aquifers is a major challenge in hydrology. Electrical self-potential (SP) is sensitive to groundwater flow through the electrokinetic effect, which is proportional to Darcy velocity. SP surveys have been extensively used for the characterization of seepage flow in a variety of contexts. But to our knowledge, a model coupling SP and groundwater flow has never been implemented for the study of stream-aquifer interactions. To address the issue, we first implemented a two-dimensional model to a synthetic stream-aquifer cross section...
October 9, 2017: Ground Water
Yong Ge Zang, Dong Mei Sun, Ping Feng, Stephan Semprich
In this study, a water-air two-phase flow model was employed to investigate the formation, extension, and dissipation of groundwater ridging induced by recharge events in a hypothetical hillslope-riparian zone, considering interactions between the liquid and gas phases in soil voids. The simulation results show that, after a rain begins, the groundwater table near the stream is elevated instantaneously and significantly, thereby generating a pressure gradient driving water toward both the stream (the discharge of groundwater to the stream) and upslope (the extension of groundwater ridging into upslope)...
October 9, 2017: Ground Water
Sergey Ishutov, Franciszek J Hasiuk, Dawn Jobe, Susan Agar
Three-dimensional (3D) printing is capable of transforming intricate digital models into tangible objects, allowing geoscientists to replicate the geometry of 3D pore networks of sedimentary rocks. We provide a refined method for building scalable pore-network models ("proxies") using stereolithography 3D printing that can be used in repeated flow experiments (e.g., core flooding, permeametry, porosimetry). Typically, this workflow involves two steps, model design and 3D printing. In this study, we explore how the addition of post-processing and validation can reduce uncertainty in the 3D-printed proxy accuracy (difference of proxy geometry from the digital model)...
September 28, 2017: Ground Water
Richard B Winston, Joseph D Ayotte
Arsenic in groundwater is a serious problem in New England, particularly for domestic well owners drawing water from bedrock aquifers. The overlying glacial aquifer generally has waters with low arsenic concentrations but is less used because of frequent loss of well water during dry periods and the vulnerability to surface-sourced bacterial contamination. An alternative, novel design for shallow wells in glacial aquifers is intended to draw water primarily from unconsolidated glacial deposits, while being resistant to drought conditions and surface contamination...
September 26, 2017: Ground Water
Alexandra Gemitzi, Venkat Lakshmi
Groundwater is a resilient water source and its importance is even greater in periods of drought. Areas such as the Mediterranean where adverse climate change effects are expected are bell-weather locations for groundwater depletion and are of considerable interest. The present study evaluates renewable groundwater stress (RGS) as the ratio of groundwater use to groundwater availability, quantifying use as the trend in gravity recovery and climate experiment-derived (GRACE) subsurface anomalies (ΔGWtrend ) and renewable groundwater availability as mean annual recharge...
September 22, 2017: Ground Water
Liang Chen, Hang Lang, Fei Liu, Song Jin, Tao Yan
Antibiotics are widely used, and there is a serious concern about its adverse impacts on the environment and human health. To our knowledge, prior to this work, there was no evidence of the potential presence of antibiotics in groundwater in China, despite populous speculations. This study reported the detection of 35 target antibiotics of 6 groups (chloramphenicois, lincosamides, marcrolides, quinolones, sulfonamides, and tetracyclines), in shallow groundwater samples collected in northern and southwestern China...
September 21, 2017: Ground Water
Cara Nadler, Kip Allander, Greg Pohll, Eric Morway, Ramon Naranjo, Justin Huntington
The impact of groundwater withdrawal on surface water is a concern of water users and water managers, particularly in the arid western United States. Capture maps are useful tools to spatially assess the impact of groundwater pumping on water sources (e.g., streamflow depletion) and are being used more frequently for conjunctive management of surface water and groundwater. Capture maps have been derived using linear groundwater flow models and rely on the principle of superposition to demonstrate the effects of pumping in various locations on resources of interest...
September 21, 2017: Ground Water
John D Bredehoeft
No abstract text is available yet for this article.
September 21, 2017: Ground Water
Troels N Vilhelmsen, Ty P A Ferré
Hydrological models are often set up to provide specific forecasts of interest. Owing to the inherent uncertainty in data used to derive model structure and used to constrain parameter variations, the model forecasts will be uncertain. Additional data collection is often performed to minimize this forecast uncertainty. Given our common financial restrictions, it is critical that we identify data with maximal information content with respect to forecast of interest. In practice, this often devolves to qualitative decisions based on expert opinion...
September 15, 2017: Ground Water
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"