Regional Aquifer-System Analysis Program of the U.S. Geological Survey, 1978-1992

Ground water in freshwater-saltwater environments of the Atlantic Coast

“…5). Although these multilayer, regional aquifer systems may be discontinuous locally, they act hydrologically as a single system on a regional scale (Sun and Johnston, 1994).…”

“…Because of their lower permeability, confining units restrict the movement of ground water into or out of adjoining aquifers. Aquifers and confining units are mapped on the basis of the degree of contrast in hydraulic conductivity among geologic units (Sun and Johnston, 1994). Generally, there is a close correlation between the type of geologic formation and its water-yielding properties.…”

Summary of hydrology of the regional aquifer systems, Gulf Coastal Plain, south-central United States

“…Many interim reports (Sun and Weeks, 1991) were released to describe progress or to document techniques, procedures, and data used during the study. Progress on the study was reported by Grubb (1985, 1986b, 1987, 1992); Wilson and Hosman (1988) described a geophysical well-log data base; Weiss and Williamson (1985) presented a method for vertically subdividing thick sedimentary units; and maps, sections, and diagrams of the geohydrologic framework were constructed by Hosman (1982Hosman ( , 1988; Arthur and Taylor (1986); Mesko (1988Mesko ( , 1990; Parks and Carmichael (1989, 1990b, 1990c; Taylor and Arthur (1989);.…”

Modeling Groundwater Flow System of a Drainage Basin in the Basement Complex Environment of Southwestern Nigera

“…For example, groundwater flow modeling could be employed to investigate groundwater system dynamics and flow patterns (Mallast et al, 2011); groundwater system response to stress ; groundwater recharge, discharge and aquifer storage processes as well as quantifying optimum aquifer yield (Freeze and Witherspoon, 1967); future anthropogenic impacts on groundwater resources (Oseji, 2010); groundwater development scenarios and alternative policies (Shao et al, 2009). In the same vein, groundwater flow model can serve as supporting planning tools for field investigations (Sun and Johnson, 1994) and as visualization tool for disseminating crucial research findings to the public and decision-makers (Sudicky et al, 1985;Sudicky, 1986). The rate and direction of groundwater flow within a given medium is controlled by hydraulic gradient, which in turn is a function of the extent of the aquifer system, the location as well as the rate of recharge and discharge (Ying et al, 2008).…”