PARAMETERS FOR ASSESSING THE SUBSURFACE WATER BEARING STRATA

Assessing the subsurface water-bearing strata is a critical task for ensuring efficient water resources management because the worth of underground water cannot be overemphasized. A clear knowledge of its occurrence and characteristics is imperative for resourceful exploitations of natural resources (groundwater). The features of the rocks hosting the underground water in the subsurface, i.e. Aquifer, were treated. Water-bearing layers are classified into aquifer, aquitard, aquiclude and aquifuge. An aquifer is categorized into unconfined, confined, leaky aquifer, perched aquifer and idealized. In addition to the recharge mode, physical parameters that determine the ability of an aquifer to retain and transmit water such as Porosity, Permeability, Transmissivity and Storativity were also discussed. This review also focuses on various techniques used for evaluating the subsurface water-bearing strata. Geophysical methods including the Schlumberger technique of Vertical Electrical Sounding in electrical resistivity and seismic refraction technique were considered as means of assessing the aquifer which provide relative information about the subsurface such as rock type and aquifer zone. Natural and artificial contaminants were finally discussed. This review aims to provide an overview of the various techniques that are suitable for assessing thesubsurface water-bearing strata.