Hydro-Geophysical Assessment of Groundwater Resources Within Parts of Omu Aran, South Western Nigeria

Abstract

Hydro-geophysical assessment of groundwater resources in part of Omu Aran South Western Nigeria has been evaluated and analyzed with a view of delineating the groundwater potentials and aquifer characteristics within the study area. Eleven-(11) vertical electrical soundings (VES) were acquired with a maximum half current electrode spacing of 75 metres using ABEM 3000 SAS Tetrameter and the sounding data were processed and interpreted using partial curve matching method by the computer iteration techniques. Results from the geo-electric sections revealed the presence of three to five geo-electric layers. The depth to water table ranges between 2.59m and 71.9m and a resistivity of 89.9 to 3072 Ωm. The depth to Watertable is deepest around Omu area with depth of 71.9m. The result of the geophysical analysis correlates positively with themselves showing similarity in geology. The result shows that the weathered basement is a primary target for ground water exploration in the studied area, as the area is void of prominent fracture which is a target for ground water exploration. It is recommended that an average depth of 7.0m should be drilled for borehole within the northern part of the studied area and a depth of about 10.0m in the southern part of the study area. All these deductions were reached after qualitative and quantitative interpretation of the geophysical data, and considering geology of the area.