Aquifer integrity test using the Dar Zarouk parameters in Emure Ekiti Southwestern Nigeria

The call for borehole drilling to exploit underground water in Emure Ekiti due to the failure/unavailability of pipe bone water engenders the application of the Dar Zarouk parameter for potential aquifer delineation, which is uncommon for the region. H and HA curve types are the most dominant sounding curves, revealing (3) to six (6) subsurface layers whose topsoil resistivity and thickness range from 42 Ω-m to 4965 Ω-m and 0.4 m and 2.1 m, respectively. The laterite layer resistivity and thickness range from 42 Ω-m to infinity (∞) and 2.9 m to 63.4 m, respectively. The fracture basement layer resistivity and thicknesses range between 112 Ω-m and ∞ , 8.1 m and 95.1 m, respectively. The weathered layer gave a resistivity value between 145 and 16100 Ω-m and a layer thickness of 61.5 m and ∞ . The fresh bedrock resistivity and depths range from 1537 Ω-m and 0.4 m to 132.4 m, respectively. The basement relief map reveals fairly deep basement depressions on the northeastern flank and basement ridges on the southwestern flank. Geoelectric parameters and maps classify the study area into poor/low, medium, and high groundwater potential zones. 80 % of Emure Ekiti is underlain by marginally thick overburden, thus constituting shallow aquifer units with poor to marginal groundwater potential. The weathered fractured basements constitute the aquifer unit. Partially weathered/fractured basements in isolated regions tend to have low to marginal groundwater yield around the northeastern flank. The results reasonably provide essential information that is expected to assist the town’s future development of groundwater resources.