Hydro-geophysical investigations for groundwater at Atan/Odosenbora area, Southwestern Nigeria

Abstract

A hydro-geophysical evaluation of the groundwater potential of the Atan/Odosenhora area of Ogun State, Southwestern Nigeria was carried out. The investigation involved the Vertical Electrical Sounding (VES) technique that applied the Schlumberger array. The study area is located within the Basement Complex terrain of Southwestern Nigeria. Migmatitic gneisses and granitic rocks underlie the area predominantly.
The data acquired from the Ten (10) VES stations were interpreted using the partial curve matching method and later subjected to computer based iteration interpretation.
A maximum of five (5) subsurface layers comprises of topsail, sandy clay, weathered basement, fractured basement and fresh bedrock have been delineated in the study area. The depth to bedrock varies from 5.5 - 53.1m with resistivity values ranging between 61 -11,292 ohm-m. The hydro-geologic study focused on measurement of depth to water table and actual depth of the hand dug wells while the geological aspect of the work was hinged on a geologic mapping. The results of hydrogeologic study show that the actual depth of the hand-dug wells ranged between 2.5 and 8.3m while the static water level varied between 0,83 and 3.3 m.
The study gave an insight lo the ground water potential of the area with the southern part of the study area having the highest potential based on the geoelectric parameters calculated.


IFE Journal of Science Vol. 9 (1) 2007 pp. 87-92