Integrated Geophysical Investigations For The Development Of A Sustainable Water Supply Scheme Within The Ekiti State University Campus Ado-Ekiti Southwestern Nigeria

ABSTRACT Reconnaissance and detailed geophysical investigations involving the Very Low Frequency Electromagnetic VLF-EM and the electrical resistivity methods have been carried out within the main campus of the Ekiti State University Ado-Ekiti. This was with a view of solving the present challenge of insufficient water supply in the University by delineating subsurface structures favourable to groundwater occurrence and upon which a sustainable water supply scheme can be developed. Forty-two 42 geophysical traverses were established and VLF-EM profiling were was carried out on the traverses at an interval of 10 m. The VLF-EM data were interpreted qualitatively and semi-quantitatively. Points on the profiles associated with structures of hydrogeological importance were selected for further investigation with the Vertical Electrical Sounding VES technique. Twenty-five 25 VES stations were occupied and the Schlumberger array was adopted with half-electrode spacing AB2 varying from 1 to 100 m. VES data were interpreted quantitatively by partial curve matching and computer modeling. The 3-layer A K and H 4-layer HA KH and QH and the 5-layer HKH depth sounding curves were obtained from the area. The 4-layer type curve is predominant having a 50 occurrence. The geoelectric sections delineated five lithologic units including the topsoil the lateritic layer the weathered layer the partly weatheredfractured basement and the fresh basement bedrock. The weathered layer and the partly weatheredfractured basement were identified as the main aquifer units in the area. VES 6 VES 11 VES 12 VES 19 and VES 22 positions were observed to possess aquifer characteristics that can only sustain low-demand water supply schemes while VES 24 and VES 25 were interpreted to have adequate aquifer characteristics that are suitable for the development of a sustainable water supply scheme.