GEOPHYSICAL EVALUATION OF THE GROUNDWATER POTENTIAL AND AQUIFER PROTECTIVE CAPACITY IN PART OF OYE-EKITI, SOUTHWESTERN NIGERIA

Abstract

Assessment of groundwater potential and aquifer protective capacity in part of Oye-Ekiti, Southwestern Nigeria using the electrical resistivity method of geophysical prospecting was carried out. The study involved Vertical Electrical Sounding (VES) technique using the Schlumberger array with current electrode spacing (AB/2) of 100 m. Thirty-one (31) VES locations were obtained with the aid of ABEM SAS 300 Resistivity Meter and plotted on the double log graph as VES curves. The VES curves were interpreted quantitatively by partial
curve matching and assisted by 1-D forward modeling using the WinResist software. The VES interpretation results (layer and thickness) were used to generate maps of the study area. A, K, H, KH, HA, QH, AA, HKH, KQH and AKH-type curves were identified in the area. The overburden thickness ranged from thick (20 to 28 m), moderate (10 to 19.9 m) to low overburden (0 to 9.9 m). The bedrock relief shows areas of moderate/high (530.1 to 558 m) and low reliefs (514 to 530m).