Read by QxMD icon Read

Ground Water

Jean-Philippe Nicot, Toti Larson, Roxana Darvari, Patrick Mickler, Michael Slotten, Jordan Aldridge, Kristine Uhlman, Ruth Costley
Understanding the source of dissolved methane in drinking-water aquifers is critical for assessing potential contributions from hydraulic fracturing in shale plays. Shallow groundwater in the Texas portion of the Haynesville Shale area (13,000 km(2) ) was sampled (70 samples) for methane and other dissolved light alkanes. Most samples were derived from the fresh water bearing Wilcox formations and show little methane except in a localized cluster of 12 water wells (17% of total) in a approximately 30 × 30 km(2) area in Southern Panola County with dissolved methane concentrations less than 10 mg/L...
January 19, 2017: Ground Water
Fred J Molz
No abstract text is available yet for this article.
January 11, 2017: Ground Water
Kamini Singha
No abstract text is available yet for this article.
January 11, 2017: Ground Water
Chao Zhuang, Zhifang Zhou, Walter A Illman
The vertical hydraulic conductivity (Kv ), elastic (Sske ), and inelastic (Sskv ) skeletal specific storage of aquitards are three of the most critical parameters in land subsidence investigations. Two new analytic methods are proposed to estimate the three parameters. The first analytic method is based on a new concept of delay time ratio for estimating Kv and Sske of an aquitard subject to long-term stable, cyclic hydraulic head changes at boundaries. The second analytic method estimates the Sskv of the aquitard subject to linearly declining hydraulic heads at boundaries...
January 10, 2017: Ground Water
Vasileios E Katzourakis, Constantinos V Chrysikopoulos
No abstract text is available yet for this article.
January 6, 2017: Ground Water
Ziv Moreno, Amir Paster
Contaminant plumes whose characteristic length is smaller than the horizontal integral scale of the hydraulic conductivity, K, are abundant in shallow, phreatic aquifers. In such cases, the aquifer can be regarded as layered, with K being only a function of the vertical coordinate. The heterogeneity of K has a critical role upon the efficiency of remediation of such sites, for example, by Pump and Treat schemes. The expected efficiency is a random variable, with uncertainty. Quantifying this uncertainty can be of great importance to decision making...
January 3, 2017: Ground Water
Hubert J Morel-Seytoux, Calvin D Miller, Cinzia Miracapillo, Steffen Mehl
Flow exchange between surface and groundwater is of great importance be it for beneficial allocation and use of water resources or for the proper exercise of water rights. In large-scale regional studies, most numerical models use coarse grid sizes, which make it difficult to provide an accurate depiction of the phenomenon. In particular, a somewhat arbitrary leakance coefficient in a third type (i.e., Cauchy, General Head) boundary condition is used to calculate the seepage discharge as a function of the difference of head in the river and in the aquifer, whose value is often found by calibration...
December 20, 2016: Ground Water
Yong Ge Zang, Dong Mei Sun, Ping Feng, Stephan Semprich
An investigation of groundwater table fluctuations induced by rainfall should consider interactions between the liquid and gas phases in soils. In this study, a water-air two-phase flow model was initially verified by simulating an infiltration experiment. It was then employed to model the interactions between liquid and gas phases regarding actions of airflow on the groundwater table and the fluctuations of the phreatic level and water level in the well induced by rainfall. The effects of airflo7w caused by rainfall on phreatic level fluctuations were also studied quantitatively by comparing the results obtained using the proposed model with those obtained from a water single-phase flow model...
December 20, 2016: Ground Water
Tariq Laattoe, Vincent E A Post, Adrian D Werner
The assumption of spatial repetition is commonly made when producing bedform scale models of the hyporheic zone. Two popular solute transport codes, MT3DMS and PHT3D, do not currently provide the necessary boundary condition required to simulate spatial periodicity in hyporheic zone transport problems. In this study, we develop a spatially periodic boundary (SPB) for solutes that is compatible with a SPB that was previously developed for MODFLOW to simulate the flow component of spatially periodic problems...
December 14, 2016: Ground Water
P G Cook, A Miller, M Shanafield, C T Simmons
The rapid expansion in unconventional gas development over the past two decades has led to concerns over the potential impacts on groundwater resources. Although numerical models are invaluable for assessing likelihood of impacts at particular sites, simpler analytical models are also useful because they help develop hydrological understanding. Analytical approaches are also valuable for preliminary assessments and to determine where more complex models are warranted. In this article, we present simple analytical solutions that can be used to predict: (1) the spatial extent of drawdown from horizontal wells drilled into the gas-bearing formation, and rate of recovery after gas production ceases; (2) the potential for upward transport of contaminants from the gas-bearing formation to shallow aquifers during hydraulic fracturing operations when pressures in the gas-bearing formation are greatly increased; and (3) the potential downward leakage of water from shallow aquifers during depressurization of gas-bearing formations...
December 12, 2016: Ground Water
Warren W Wood, J K Böhlke
Subsurface brines with high nitrate (NO3(-) ) concentration are common in desert environments as atmospheric nitrogen is concentrated by the evaporation of precipitation and little nitrogen uptake. However, in addition to having an elevated mean concentration of ∼525 mg/L (as N), NO3- in the coastal sabkhas of Abu Dhabi is enriched in (15) N (mean δ(15) N ∼17‰), which is an enigma. A NO3(-) solute mass balance analysis of the sabkha aquifer system suggests that more than 90% of the nitrogen is from local atmospheric deposition and the remainder from ascending brine...
November 28, 2016: Ground Water
Lee J Florea, Dave Hart, James Tinjum, Chris Choi
No abstract text is available yet for this article.
November 17, 2016: Ground Water
Ilaria Butera, Claudia Soffia
In practical situations concerning aquifers, time and/or economic restraints often make it impossible to construct numerical models, and in these cases simple methodologies could be useful, at least for feasibility studies. In this context, the present manuscript deals with the use of a straightforward cokriging method to use data acquired from a monitoring network (transmissivity, piezometric head and trajectory data) in order to obtain useful information about the characteristics of the aquifer. Two issues have been addressed: estimation of the solute path and estimation of the transmissivity...
November 10, 2016: Ground Water
(no author information available yet)
No abstract text is available yet for this article.
November 2016: Ground Water
Rebecca Louise Nelson, Debra Perrone
The Sustainable Groundwater Management Act (SGMA) aims to control, for the first time in California's history, the state's significant use and depletion of groundwater. SGMA gives local agencies a high degree of discretion in relation to a new permitting power, but the discretion is a double-edged sword: agencies gain maximum flexibility to tailor their regime to local conditions, yet the statute provides no direction on appropriate components of a groundwater permitting regime. We introduce SGMA and the broader legislative context to its permitting power, and we explain the continuing common law context in which the legislation operates...
November 2016: Ground Water
Carl Hauge
No abstract text is available yet for this article.
November 2016: Ground Water
Rebecca Nelson, Debra Perrone
No abstract text is available yet for this article.
November 2016: Ground Water
William M Alley, Lisa Beutler, Michael E Campana, Sharon B Megdal, John C Tracy
No abstract text is available yet for this article.
November 2016: Ground Water
Shrikant Daji Limaye
No abstract text is available yet for this article.
November 2016: Ground Water
Vicki Kretsinger Grabert, Dawn Samara Kaback
No abstract text is available yet for this article.
November 2016: 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"