نتایج جستجو برای: aquifers

تعداد نتایج: 4722  

Journal: :journal of mining and environment 2010
r. n. singh a.s. atkins a.g. pathan

ground water and surface water create a range of problems in lignite mining utilizing surface mining methods. in order to create a safe and economic mining environment, it is essential to carry out mining after dewatering the rock mass surrounding the lignite mines by advance dewatering techniques. this paper briefly describes the ground water regimes including pressure gradients associated wit...

Journal: :Water resources research 2015
Alexandra S Richey Brian F Thomas Min-Hui Lo John T Reager James S Famiglietti Katalyn Voss Sean Swenson Matthew Rodell

Renewable groundwater stress is quantified in the world's largest aquifersCharacteristic stress regimes are defined to determine the severity of stressOverstressed aquifers are mainly in rangeland biomes with some croplands.

ژورنال: علوم آب و خاک 2020

Understanding the quality of groundwater resources, which are the largest available freshwater reservoir, is one of the needs in planning and developing water resources. The purpose of this research was to study the quality changes of groundwater resources in the upstream aquifers of Zayandehrood Dam (1995-2016) and to evaluate water quality in terms of drinking and agricultural consumption and...

2011
RL Johnson BR Clark MK Landon LJ Kauffman SM Eberts

Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single inactive multi-aquifer well can contribute near...

2017
Vitaly A. Zlotnik Glenn Ledder Vitaly Zlotnik

A theory of dipole flow is developed to model flow induced by a vertical circulation well consisting of injection and extraction chambers in a single borehole. Included in the theory are an analytical description of the kinematic flow structure around a vertical circulation well and the drawdown in the well chambers. Using Stokes' stream function, simple criteria are derived to determine the re...

Journal: :Environmental science & technology 2007
Mark A Borchardt Kenneth R Bradbury Madeline B Gotkowitz John A Cherry Beth L Parker

Confined aquifers are overlain by low-permeability aquitards that are commonly assumed to protect underlying aquifers from microbial contaminants. However, empirical data on microbial contamination beneath aquitards is limited. This study determined the occurrence of human pathogenic viruses in well water from a deep sandstone aquifer confined by a regionally extensive shale aquitard. Three pub...

2017
Jadwiga R. Ziolkowska Reuben Reyes Athanasios Loukas

In the past decade, extreme and exceptional droughts have significantly impacted many economic sectors in the US, especially in California, Oklahoma, and Texas. The record drought of 2011–2014 affected almost 90% of Texas areas and 95% of Oklahoma state areas. In 2011 alone, around $1.6 billion in agricultural production were lost as a result of drought in Oklahoma, and $7.6 billion in Texas. T...

Journal: :Ground water 2007
Emily Godfrey William W Woessner Mark J Benotti

Human use of pharmaceuticals results in the excretion and disposal of compounds that become part of municipal and domestic waste streams. On-site waste water disposal and leaking city sewer systems can provide avenues for the migration of effluent to the underlying aquifers. This research assessed the occurrence and persistence of 22 target pharmaceuticals in septic tank effluent and two shallo...

Journal: :Ground water 2007
Calvin D Miller Deanna Durnford Mary R Halstead Jon Altenhofen Val Flory

A semianalytical method commonly used for quantifying stream depletion caused by ground water pumping was reviewed for applicability in narrow alluvial aquifers. This stream depletion factor (SDF) method is based on the analytic Glover model, but uses a numerical model-derived input parameter, called the SDF, to partly account for mathematically nonideal conditions such as variable transmissivi...

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