Journal of Applied Sciences 1812-5654 1812-5662 Asian Network for Scientific Information 10.3923/jas.2015.741.751 Abudulawal Lukuman Amidu Sikiru A. Apanpa Kasim A. Adeagbo Olusola A. Akinbiyi Olukole A. 5 2015 15 5 Acute drinkable-water shortage is an important problem confronting the people of Erunmu, a suburb of Ibadan, southwestern Nigeria. Geophysical survey was carried out to evaluate the groundwater potential of the basement complex and to delineate potential locations for siting boreholes in the study area. A total of twenty five Vertical Electrical Soundings (VES) were carried out. Data acquisition involved the use of the Schlumberger electrode configuration with half current electrode spacing (AB/2) ranging from 1-100 m. Interpretation of the geoelectrical data involved the use of curve matching technique and computer iteration. Geoelectrical cross sections and isoresistivity and 3D isopach maps were constructed based on lateral combination of inverted soundings from the VES surveys. Available lithologic data from hand-dug wells were used to evaluate geophysical results. The interpretation revealed three and four-model curves H-, HA-, A- and KH-types, with the the H-type curves being the dominant types. Four subsurface layers comprising top lateritic soil, weathered layer, fractured basement and fresh basement were inferred from the interpretation. The top soils are of varying thickness and resistivity values. The fractured and weathered basement with relatively lower resistivity are inferred to be the aquiferous zone and could bear productive water for groundwater supply. The basement was inferred as the lowermost infinitely thick layer with resistivity mostly greater than 1500 Ωm. The results of the soundings greatly contribute to the understanding of the hydrogeology of the basement complex. The fractured and weathered basement aquifers can be developed for sustainable water supply to Erunmu and adjacent communities.

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