Determination of groundwater potential using electrical resistivity survey and borehole logging in sites I and III of Delta State University, Abraka Nigeria

Abstract

This study examines the aquifer properties and lithological structure of Abraka, Nigeria, specifically the Delta State University Site I and III environs. Ten Schlumberger geoelectric soundings, geophysical well logging and pumping test method were employed using an ABEM Terrameter. A drilled water well and existing borehole data were used for this study. The result of the lithological study revealed that the subsurface formations consist of topsoil, lateritic sand, fine and medium grain sand mixed with clay. The topsoil is brownish with thickness of 2 m, the laterite is reddish with thickness of 4 m, the fine sand is whitish with thickness of 10 m, and the medium sand is also whitish with thickness >12 m. The results of the evaluation of the geoelectric data using curve matching and Win Resist computer iteration was in strong agreement with that of the well record, with a subsurface that is composed of 4 to 6 geo-electric layers. The depth ranges from 13.5m to 97.8m while the resistivity ranges from 1021.2 Ωm to 9092.4 Ωm. A core soil sample collected at an interval of 5m, spontaneous potential and resistivity logs were carried out on the well. The hydraulic conductivity, well's transmissivity, storativity, and specific capacity are 102.7m²/day, 5.14 m/day, 0.00062 and 0.39 m³/m respectively. It is recommended that a drill depth of 30 m and above should be accessed for potable water in the area. From the result of this survey, we infer that this aquifer is confined and capable of supplying the people with adequate and good quality drinking water.