Geo-Electrical Exploration for Groundwater in Eiyenkorin, Ajelanwa and Owa-Otun Communities in Kwara State, Nigeria

Schlumberger Vertical Electrical Soundings (VES) for groundwater exploration in Eiyenkorin, Ajelanwa and Owa-Otun communities in the Basement Complex terrain of the southwestern Nigeria were carried out with a view to establishing the different subsurface geoelectric layers and the aquifer units. Data were collected from 4, 5 and 15 VES stations at Ajelanwa, Owa-Otun and Eiyenkorin communities respectively. From the quantitative interpretations of the data collected, using the usual method of curve matching with the Orellana-Mooney Master curves and 1-D forward modeling with WinResist 1.0 version software, between four and five lithologic units were identified in these Communities. These include: the topsoil, the lateritic layer, the weathered layer, the partly weathered/fractured basement and the fresh basement. The weathered layer and the partly weathered/fractured basement constitute the main aquifer units. The depth to bedrock at the chosen VES locations vary from 3.7 to 23.8 m at Eiyenkorin, 6 to 30 m at Ajelanwa, and 7 to 13 m at Owa Otun communities. Some lobes or areas of low resistivity which constitute the prospective zones for water exploration in these areas have been delineated.