Delineation of Aquifer Fluids for Groundwater Prospecting Using a Digital-Analogue Terrameter in Rumuosi, Rivers State

Abstract

Groundwater remains the most reliable source of potable water in the Niger Delta due to inadequate public supply and increasing urbanization. This study focuses on the delineation of aquifer fluids for groundwater prospecting in Rumuosi, Rivers State, using a digital–analogue terrameter. The aim was to characterize subsurface aquifer zones, evaluate fluid properties, and recommend viable groundwater prospects. Electrical resistivity surveys were conducted using the Schlumberger configuration for Vertical Electrical Sounding (VES) and selected 2D profiles. Data acquisition involved systematic electrode expansion to probe shallow and deeper subsurface horizons, with resistivity inversion applied to generate geoelectric models. The results revealed shallow conductive zones (0–20m) associated with contaminant plumes and clay-rich sediments, overlying more resistive aquiferous layers between 22–45m. Productive confined aquifers were delineated at depths beyond 45m, with the most promising horizons occurring between 50–110m and extending laterally up to 90m horizontal spread. These resistive zones correspond to freshwater aquifers with high porosity and permeability, suitable for sustainable borehole development. However, vulnerability was noted in areas where conductive plumes migrate downward, threatening aquifer integrity in the long term. The study concludes that deeper confined aquifers in Rumuosi remain viable for groundwater exploitation, provided protective casing and monitoring are implemented. This research demonstrates the effectiveness of resistivity methods in aquifer fluid delineation, supporting sustainable water resource planning in the Niger Delta.