GIS-BASED GROUNDWATER POTENTIAL ZONATION AND AQUIFER CHARACTERIZATION IN OTUKPO AND ENVIRONS, BENUE STATE, NIGERIA
Water scarcity remains a perennial challenge in many parts of Sub-Saharan Africa, particularly in regions with high dependence on groundwater resources amid climate variability, population growth, and increasing anthropogenic pressures. Existing studies relied primarily on static geophysical and hydrochemical data, lacking the predictive capacity needed for dynamic management under various pumping and climate scenarios. This research addresses this critical gap by applying an integrated approach using geophysical surveys, pumping tests, GIS-based multi-criteria analysis to characterize the aquifer system, evaluate groundwater potential, and simulate flow dynamics for informed decision-making. This study combined 15 Vertical Electrical Sounding) surveys (Schlumberger array, AB/2 up to 217m) analyzed in IPI2WIN, 15 pumping tests evaluated via the Theis method in AQTESOLV, and GIS-based Multi-Criteria Decision Analysis (MCDA) using Analytic Hierarchy Process in ArcGIS. Hydraulic conductivity ranged from 7.59 to 54.09 m/day (mean 29.35 m/day), and transmissivity from 145.83 to 1167.50 m²/day (mean 740 m²/day). IDW interpolation, reclassification, and AHP-weighted overlay delineated Groundwater Potential Zones: 35.5% very high, 40.7% high, 17.5% moderate, and 6.2% low. A strong correlation (R = 0.998) between VES and pumping test parameters validated the approach. Zonal statistics and ANOVA confirmed significant head variability across zones (F = 395.2, p < 0.001). Recommendations prioritize 60–80 m boreholes (360–500 m³/day abstraction) in very high zones. This framework offers a replicable model for sustainable management in data-scarce sedimentary basins.
Authors : Omepa, C., Ankidawa, B.A., Tya, T.S.K., Inuwa A.M., Usman, M.N. and Chataimada, J.
Category : Open Access Volume (Issue) : 11(2) Date Uploaded : 24th September 2026