Investigation Of Basement Aquifer Hydraulics And Protective Capacity Within Jimgbe And Environs, North Central Nigeria

Abstract

Different geological elements, including faults/folds, fractures, and hydrogeological units, influence an area's groundwater availability. An evaluation of the study region's hydrological characteristics, such as groundwater availability, aquifer depth, the division of the subsurface into distinct geo-electric layers, and the categorization of the underlying geology as fresh basement, weathered basement, or fractured bedrock, is the goal of this study. Using the Schlumberger arrangement, Vertical Electric Sounding (VES) was used to collect data in 15 sites. A software called WinResist was used to process the data and plot it in order to create the curves. By doing this, the data's inherent noise and field inaccuracies are eliminated. Aquifer resistivity and thickness were calculated from the curves in order to determine the Dar Zarrouk characteristics. There are five (5) geo-electric strata, according to the results. Top soil with lateritic clay has resistivity and thickness between 9.9-288.8 Ωm and 0.9-6.6 m; the weathered basement layer has thickness and resistivity between 8.0-717 Ωm and 0.8-34.2 m; the confining fairly weathered basement has thickness and resistivity between 3.2-106.9 m and 63.6-70636.0 Ωm; and the weathered/fractured basement aquifer has thickness and resistivity between 299.1-1997.0 Ωm and 4.1-29.7 m. The resistivity of the newly constructed basement ranges from 2778.8 to 10,0000.0 Ωm, and its thickness is unknown. The range of values for the aquifer resistivity, hydraulic conductivity, and transmissivity is 299.1-5438.0 Ωm, 0.049-1.895 m/day, and 0.284-23.243 m2/day, respectively. Based on weathered and fractured aquifers, this showed that most VES areas have moderate to good groundwater potential. However, with values ranging from 0.0004-0.0405 mhom, its aquifer protection capacity is inadequate. This demonstrated the aquifer's susceptibility to pollution and the need for appropriate groundwater development both before and after drilling operations.