Research article

Evaluation of Aquifer Protective Capacity and Soil Corrosivity Using Vertical Electrical Sounding Data in Umuahia North L.G.A., Abia, South-Eastern Nigeria

*Terhemba Emberga and Epuerie Emeka

Department of Physics/Electronics, Federal Polytechnic Nekede, Owerri

*Corresponding author: terhemba4sure@yahoo.com; Phone: 08037513494

Received 29 April, 2024                                            Accepted 15 August, 2024                                            Published 30 August, 2024

Abstract

A Geoelectric survey was carried out in Umuahia North Local Government Area of Abia State in South-Eastern Nigeria, with the aim of evaluating the aquifer protective capacity and soil corrosivity of overburden units in the study area using Vertical Electrical Sounding (VES) method. A resistivity meter (terrameter) was employed to obtain the field data of thirty (30) VES points within the study area. The information obtained from software modeling of the field data was used to evaluate longitudinal conductance and transmissivities of the layers. From the modeled VES data, it was observed that all the thirty VES points were having an average of ten layers. The minimum and maximum resistivity obtained in the study area ranges from 1.20Ωm to 42,300Ωm, representing shale and sandstone intercalated with gravel. There exists resistivity overlapping values between moderately resistive and highly conductive geo-materials. The apparent depths of the geo-electric layers ranged from 0.3 to 269 Metres, while thicknesses of the geo-electric layers varied between 0.3 to approximately 107 meters. The study area was deduced to be 35.7% essentially non-corrosive, 20% slightly corrosive, 3.3% moderately corrosive, 20% corrosive, 16.7% highly corrosive and 3.3% extremely corrosive. Also, the evaluation of the longitudinal conductance of the study area showed that it is characterized by poor aquifer protective capacity at 56.7%, weak aquifer protective capacity at 13.3%, moderate aquifer protective capacity at 16.7% and good aquifer protective capacity at 13.3%. These evaluations help to deduce suitable locations for the siting of boreholes as well as adequate measures to be taken in the process.

Keywords: Aquifer, Protective Capacity, Soil Corrosivity, Vertical Electrical Sounding