Geo-electrical Exploration for Groundwater in Jimba-Oja, Ifelodun Local Government Area of Kwara State, Nigeria

Abstract

Vertical Electrical Soundings (VES) and Horizontal Profilings (HP) forgroundwater exploration in the Agricultural and Rural Management TrainingInstitute (ARMTI) and National Centre for Agricultural Mechanization(NCAM), both located at Jimba-Oja, Ifelodun Local Government Area (LGA) ofKwara state, were carried out with a view to establishing the differentsubsurface geo-electric layers, the aquifer units and their hydrogeologicparameters. Data were collected from 25 VES stations situated within latitudes4 0 39’ and 4 0 41’ and longitudes 8 0 22’ and 8 0 23.5’, three of which have beendrilled. From the quantitative interpretation of the data collected, using theusual method of curve matching with the Orellana-Mooney Master curves and1-D forward modeling with WinResist 1.0 version software, four lithologic unitswere identified. These include: the topsoil, the lateritic layer, theweathered/fractured layer and the fresh basement. The weathered/fracturedbasement constitutes the main acquifer unit. The isopach map of theoverburden shows depth to the bedrock varying from 2.8 to 28m. Thegeoelectrical interpretation of data obtained in this area has permitted thedelineation of a lobe of low resistivity which constitutes the prospective zonefor water exploration in the area.