An intercalated dual geoelectrical survey of an earlier study for groundwater at the planned Gidan Kwano Campus Development Phase II, Federal University of Technology, Minna, Nigeria

Abstract

The earlier study at the planned Gidan Kwano Campus was a sole vertical electrical sounding (VES) survey concerned with identifying aquifer prospects, as well as providing geotechnical 2 information for a 2km areal extent subsumed in the greater Phase II Development. The aim of the present study is to plug the knowledge gaps of geological information for the intervening 200m- spread station spacing of the earlier survey; the objectives herein are to validate the conclusions drawn with respect to aquifer prospects from the earlier survey using the earlier method and an IP discriminator and define a framework by which studies of this format (i.e. georeferenced) could easily be replicated. Because of the dual vertical electrical sounding-induced polarisation (IP) 2 nature of this survey, the areal extent of this project work was limited to 1km and survey proceeded in the transverse traverse (i.e. TT) sense for individual stations and a south-north profile. Initially, each of the thirty-six intercalated survey stations, six on a TT, were georeferenced in terms of their x, y, z variables (i.e. latitude, longitude, elevation) using the hand-held Garmin72 Global Positioning System (GPS) unit. The Schlumberger array of the VES mode was employed for both the resistivity and the induced polarisation surveys. The results obtained indicated that the following VES locations are considered good prospects for groundwater: TT1-2, TT1-3, TT1-4, TT1-6, TT2-1, TT2-2, TT2-3, TT2-4, TT3-1, TT3-2, TT3-3, TT3-4, TT3-5, TT4-1, TT4-2, TT4- 3, TT4-4, TT4-5, TT5-1 TT5-2, TT5-4, TT5-5, TT6-5, and TT6-6. The IP data set was used in a qualitative sense for this survey to constrain the conclusion drawn regarding the most promising VES locations of TT5-4, TT1-2, TT1-3, and TT2-2.