DETERMINATION OF AQUIFER THICKNESS IN SAPELE ROAD AREA IN BENIN CITY, EDO STATE USING VERTICAL ELECTRICAL SOUNDING(VES) METHOD.

ABSTRACT

A geophysical survey using vertical electrical sounding (VES) was undertaken along Sapele Road Area of Benin city in an attempt to ascertain aquifer thickness for groundwater exploitation. Four (4) vertical electrical soundings with electrode spacing of 316m AB/2 were occupied along the traverse, with the aid of ABEM SAS 300C Terrameter set. The data were interpreted using computer – assisted iterative interpretation based on IP12 WINREST Package. The subsurface stratigraphy is as follows; (47.2-587.8Ωm); topsoil, (210.8-326.1Ωm); Clayey Sand, (447.0-1115.7Ωm); Latertic Sand, (394.4-1055.9Ωm); sand, (1524.0-1898.0Ωm and 576.0-1858.0 Ωm); dry sand, and (845.5-1586.5Ωm); as saturated sand (aquifer). The results reveal depth to water table ranges of 58.6- 105.3m. The range of values of thickness of the aquifer across the VES is from 45.2-57.5m.