Geoelectrical assessment of groundwater potential at Ewuloja and its environs in Simawa Area, southwestern Nigeria

Groundwater potential assessment using the vertical electrical sounding (VES) technique was carried out at at Ewuloja and its environs in Simawa Southwestern, Nigeria with a view to solving the problem of incessant failure of groundwater boreholes in the study area. A total of 40 VES were carried-out using Schlumberger electrode configuration. The data was interpreted quantitatively using the partial curve matching and computer iteration techniques to generate the first order geoelectric parameters. The borehole lithological log was used to constrain the conventional VES interpretation. The VES results aided by the borehole lithological log reveal four to seven distinct subsurface geologic layers which correspond to Top soil, Lateritic clayey sand, Sand, Sandstone and Consolidated sandstone. The analysis shows that sands at the upper layer within the depth of 2.3 - 76.2 m are unsaturated while sands at depth not less than 100 m in some sampling points are saturated and denote the aquifer units in the study area. Boreholes/deep wells could be cited at these points at depth interval 150 - 210 m. This study has provided an insight to the subsurface condition of the aquifer systems and delineated areas for probable groundwater development in Simawa community.Keywords: Vertical electrical sounding, aquifer, consolidated sandstone, earth resistivity, lateritic cla