Evaluation of Groundwater Potential of Part of Phase one, Federal University Oye-Ekiti using Electromagnetics and Electrical Resistivity Methods

Abstract

Geophysical investigation was carried out at Innovation area of phase 1,
Federal University Oye-Ekiti. It was aimed at evaluating the groundwater
potential of the area. Very Low Frequency Electromagnetic (VLF-EM) and
Electrical Resistivity (ER) methods were adopted for the investigation. Six (6)
VLF-EM profiles were generated and conductive zones characterized by linear
structures which serve as conduit for underground fluid transmission and
storage were delineated. Twelve (12) Vertical Electrical Soundings (VES)
guided by the EM-VLF results to target the identified conductive zones were
occupied. Two (2) factors that can serve as good indicators for the existence of
promising groundwater were used to rate the potential of groundwater in the
area. The results show that the geoelectric type curves which characterised the
area are the H and KH. Three (3) geologic units comprising of topsoil/laterite,
weathered layer and fresh basement were delineated. The weathered layer
constitutes the aquifer unit in the study area. The resistivity and thickness of the
weathered layer ranged from 40 to 223 Ωm and 7.2 to 23.1 m respectively.
Generally, the groundwater potential of the study area is rated low in the north
and medium in the south around VES 9, 8 and 1 which have weathered layer
thicknesses of 23.1, 15.4 and 11.9 m and resistivity values of 223, 95 and 87 Ωm
respectively and show prominent zones for groundwater abstraction