Groundwater Investigation using Dar Zarrouk Parameters for Hydrogeological Subsurface Assessment in Niger State Polytechnic, Zungeru

Groundwater Investigation, Dar Zarrouk Parameters, Vertical Electrical Sounding (VES), Hydrogeological Assessment

Abstract

Groundwater constitutes the principal source of water for domestic and institutional use at Niger State Polytechnic, Zungeru, necessitating a detailed evaluation of its hydrogeological potential. This study employed Dar Zarrouk parameters derived from Vertical Electrical Sounding (VES) data to characterize the subsurface and assess aquifer properties within the Polytechnic environment. A total of forty (40) VES stations were acquired using the Schlumberger array, and data interpretation through curve matching and computer iteration delineated subsurface layers and aquifer characteristics. Results identified three to four lithological units: topsoil/lateritic cover, clay, sandy clay, clayey sand, weathered basement, and fresh basement. Dar Zarrouk parameters, such as longitudinal conductance, transverse resistance, hydraulic conductivity, transmissivity, reflection coefficient, and anisotropy, provided insights into aquifer protective capacity and groundwater potential. Aquifer resistivity ranged from 2-402 Ωm, with thicknesses of 0.6-19.6 m, while basement resistivity exceeded 1,000 Ωm, confirming a crystalline bedrock. High transmissivity and hydraulic conductivity at VES 1, 6, 11, 25, and 36 denote productive aquifers, whereas clayey zones showed poor recharge. Groundwater occurrence is predominantly associated with weathered and fractured basement zones, which constitute the main aquifers. It is recommended that borehole development target these zones to ensure a sustainable water supply for the Polytechnic and surrounding communities.