Investigation of Groundwater Potential Using Electrical Resistivity Method, in Iddo Community Grammar School, Iddo-Okpella, Edo State

Abstract

Vertical electrical sounding (VES) resistivity technique was used to investigate the ground water potential at Iddo Community Grammar School, Iddo-Okpella, Edo State, Nigeria. A total of 36 VES points consisting of six profiles with six VES points per profile were covered. Data from the Schlumberger vertical electrical sounding were presented as geo- electric sections, iso-resistivity maps, regolith and depth to basement maps. The resistivity field data were interpreted using partial curve matching approach and iterative resistivity sounding interpretation software-WinResist Version 1.0. The results from the interpretations showed that three to four geoelectric sections were delineated: the top layer has a thickness ranging from 0.2 m to 2.1 m with resistivity range of 91.5 Ωm to 1195.5 Ωm, the thickness of the second layer ranges from 2.0 to 14.2 m with resistivity values ranging from 20.5 Ωm to 916.80 Ωm and the thickness of the third layer ranges from 2.7 m to 14.7 m with resistivity values between 8.0 Ωm and 4328.10 Ωm and resistivity of the basement has the maximum of 4328.10 Ωm. VES C6, D3, D6, E4, E5, F1, F2 and F5 in the study area have relatively high regolith thickness and high conductivity values. Considering the aquifer characteristics in terms of thickness-resistivity values, it is recommended that groundwater developments should be concentrated around VES C6 (10.6m), D3(9.0m), D6(15.0m), E4(12.8m), E5(16.7m), F1(10.8m), F2(11.1m) and F5(12.1m) of the study area.