Appraisal of Aquifer Protective Capacity and Soil Corrosivity Using Electrical Resistivity Method in Miango Area, Jos, Plateau State, Nigeria

Abstract

A geophysical survey was carried out in Miango area, Bassa Local Government Area of Plateau State, northcentral Nigeria using Electrical resistivity soundings. This study aimed at delineating zones that are very prone to groundwater contamination from surface contaminants and subsurface soils that are corrosive to utility pipes. Schlumberger configurations were employed to delineate the subsurface geologic layers, corrosivity level and aquifer protective capacity. Five (5) transverses were mapped out along which thirty-nine (39) Vertical Electrical Sounding (VES) data were acquired using D.C. SAS 2000 resistivity
meter with half-current electrode separation (AB/2) of 1 to 125 m. The interpretations of the data collected were aided by computer assisted iterative using 1-D inversion technique (IX1D), MS Excel 2016 and surfer 11 software. Sounding curve types observed in the area are mostly the QH, H, and HA curves. Five (5) distinct geoelectric layers were identified namely: topsoil, clayey layer, laterite, fractured basement and fresh basement. The measured overburden thickness ranges from 0.78 to 42 m and the longitudinal conductance of the overburden units ranging from 0.002142 to 1.260121 mhos. The pink colour region have
relatively high topsoil resistivity value and is practically noncorrosive, while the green colour region is slightly corrosive. Based on the longitudinal conductance values; poor, weak, moderate and good aquifer protective capacity zones were defined. The poor and weak protective capacity zones are vulnerable to surface contamination while the moderate and good protective capacity zones have higher protective property to prevent contaminated fluids infiltrations into the aquifer.