GEO-ELECTRIC ASSESSMENT OF GROUNDWATER POTENTIAL OF THE BASEMENT COMPLEX WITHIN THE FEDERAL POLYTECHNIC EDE AND ENVIRONS, OSUN STATE, SOUTH-WEST, NIGERIA

Abstract

An assessment of the groundwater potential of the basement complex within the Federal Polytechnic, Ede, south-west Nigeria, was conducted. Twenty-five points were systematically chosen within the North campus of the Federal Polytechnic and its environs, and assessed for aquifer’s groundwater potentials, groundwater development, and reasons for the failure of some abandoned wells within the study area. The study was conducted using some geological investigations and electrical resistivity methods such as horizontal profiling and vertical electrical sounding using the Wenner array and Schlumberger configuration. Indications from the result show that the electrical resistivity values of the study area range from 40 to 85Ωm, 90 to 120 and 120 to 1,230Ωm. Further analysis of the result using specific interpretative models classified the study area into three potential groundwater zones, namely high groundwater potential terrain, low to medium groundwater potential terrain and poor to lean potential groundwater terrain. The investigation also revealed that the failure of the boreholes situated within the sports complex beside the rector’s office and the one at the staff club were the result of sinking the boreholes in a poor to lean potential groundwater terrain. Similarly, boreholes sank within the high groundwater potential and sourced their water from the weathered and fractured zone, which formed the aquifer within the basement complex of the study area.