Recharge events that deliver electron acceptors such as O2, NO3, SO4, and Fe3+ to anaerobic, contaminated aquifers are likely important for natural attenuation processes. However, the specific influence of recharge on (bio)geochemical processes in ground water systems is not well understood. The impact of a moderate-sized recharge event on ground water chemistry was evaluated at a shallow, sand...

regarding to increased use of groundwater resources, it seems necessary to have more accurate knowledge of characteristics of aquifers in order to improved usage and accurate management of these resources. in this study, we simulated groundwater flow of qazvin aquifer usingvisual modflow model, collecting data and statistics, as well as using different studies. the simulation model has operated...

In this work, studies of underground gas storage (UGS) were performed on a partially depleted, naturally fractured gas reservoir through compositional simulation. Reservoir dynamic model was calibrated by history matching of about 20 years of researvoir production. Effects of fracture parameters, i.e. fracture shape factor, fracture permeability and porosity were studied. Results show...

this paper presents an analytical model characterizing unsteady groundwater flow in an unconfined aquifer resting on a sloping impervious bed. the aquifer is in contact with a constant water level at one end. the other end is connected to a stream whose level is increasing form an initial level to a final level at a known exponentially decaying function of time. moreover, the aquifer is repleni...

The loading efficiency (sometimes called the tidal efficiency) is often neglected when simulating the head response in an aquifer to water level changes in lakes and streams. This is not appropriate when the lake or stream only partially penetrates the aquifer. In such cases, the aquifer extends below the lake or stream and is hydraulically connected through a semiconfining layer of lower perme...

While tomographic inversion has been successfully applied to laboratory- and field-scale tests, here we address the new issue of scale that arises when extending the method to a basin. Specifically, we apply the hydraulic tomography (HT) concept to jointly interpret four multiwell aquifer tests in a synthetic basin to illustrate the superiority of this approach to a more traditional Theis analy...

More ecient methods are needed for the in situ evaluation of solute sorption to aquifer sediments. The objective of this study was to develop a simpli®ed method for estimating retardation factors for injected solutes from ``push±pull'' test extraction phase breakthrough curves (BTCs). Sensitivity analyses based on numerical simulations were used to evaluate the method performance for a variety...

The study focused on the seepage of uranium from unlined tailing dams into the alluvial aquifer in the Gawib River floodplain in Namibia where the region solely relies on groundwater for its economic activities as a result of arid climatic condition. The study reviewed previous works besides water sample collection and analyses for major ions, metals and environmental isotopes in addition to fi...

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...