Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. iii Figures 1-4. Maps showing: 1. Study area, regions within the study area, and all well...

[1] In many coastal areas, land has been reclaimed by dumping fill materials into the sea. Land reclamation may have a significant effect on groundwater regimes, especially when the reclamation is at large scale. Analytical studies on the impact of land reclamation on steady-state ground water flow conditions were conducted previously, but transient analytical solutions are not yet available. T...

Mining throughout the Floridan aquifer system alters groundwater conditions. Determination of magnitude and extent of groundwater alterations in this regional karst aquifer system is difficult due to preferential flow paths, blasting, and widespread aquifer withdrawals and injections. Additionally, hydrologic models do not reveal subsurface impacts to the biotic environment, such as destruction...

Ground-water availability from the High Plains aquifer in Southwest Kansas Ground-water Management District 3 (GMD 3) is declining as it is elsewhere in the western part of the state (Figure 1). Water-use density, defined as the annual amount of water pumped from the aquifer per unit of land area, is high over much of the District and greatly exceeds annual recharge (McMahon et al., 2003). Subs...

[1] The estimation of catchment-averaged aquifer hydraulic conductivity values is usually performed through a base flow recession analysis. Relationships between the first time derivatives of the base flow and the base flow values themselves, derived for small and large values of time, are used for this purpose. However, in the derivation of the short-time equations, an initially fully saturate...

Groundwater environments provide habitats for diverse microbial communities, and although Archaea usually represent a minor fraction of communities, they are involved in key biogeochemical cycles. We analysed the archaeal diversity within a mixed carbonate-rock/siliciclastic-rock aquifer system, vertically from surface soils to subsurface groundwater including aquifer and aquitard rocks. Archae...

A sharp interface numerical model is developed to simulate saltwater intrusion in multilayered coastal aquifer systems. The model takes into account the flow dynamics of salt water and fresh water assuming a sharp interface between the two liquids. In contrast to previous two-fluid flow models which were formulated using the hydraulic heads of fresh water and salt water as the dependent variabl...

Overutilization of groundwater resources can put their quality under stress. It could be base on rapid declination in groundwater level leading to salt water intrusion in the coastal aquifers. The objective of this study was to map the vulnerability of salt water intrusion of the Urmia Lake, Iran to nearby coastal aquifer (Azarshahr) using GALDIT method. The GALDIT index based on six parameters...

Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a re...

This paper presents the analytical solution of groundwater response to tidal fluctuation in a coastal multilayer aquifer system consisting of a leaky confined aquifer, a semipermeable layer, and an unconfined aquifer. The semipermeable layer, or the roof of the leaky confined aquifer, extends under the sea. Comparisons are made with solutions derived previously, which considered only a single a...