Determination of groundwater potential in Asaba, Nigeria using surface geoelectric sounding

Abstract

Providing potable water has been a major concern to the people of Asaba the capital city of Delta State, Nigeria. This study which is aimed at identifying formations that present fresh and healthy aquifer water for the people employed the use of the geoelectric sounding to probe the subsurface. Data collected were interpreted in terms of the true resistivity and thickness of subsurface layers and result correlated with record from existing borehole. Results indicate that there are four to five distinct formations in the study area. Analyses of the data suggest that water bearing formation exist in the third formation having resistivity range of 318 to 567 Ωm. The thickness of the aquifer ranges from 20.4 to 33.9 m, while the depth range is from 43.5 to 52.8 m. The study therefore indicates the presence of thick and highly prolific aquifer zone which is an indication of adequate water resource in the area. It is recommended that boreholes for good drinking water and water scheme be drilled to the third layer of the various locations investigated. Key words: Schlumberger array, groundwater, geoelectric sounding, electrical resistivity, aquifer, electrode separation.