Integration of aeromagnetic and electrical resistivity imaging for groundwater potential assessments of coastal plain sands area of Ado-Odo/Ota in southwest Nigeria

Abstract

This study aims to investigate the groundwater potential of Coastal Plain Sands area of Ado-Odo/Ota within Dahomey Basin using the integration of aeromagnetic method and electrical resistivity imaging. The aeromagnetic method is applied to reveal the possible hydrogeological structures (such as lineament or fracture) buried in the subsurface. The lineaments which are interconnected are observed in the eastern part of the study area while the western part is void of the interconnectivity of lineaments. Resistivity technique is applied in regions where there are interconnectivity and non-interconnectivity of lineament to delineate occurrence of groundwater about the observed lineament. The depths to magnetic sources range between 102.6 and 1965.2 m. Furthermore, the result of resistivity technique shows that the depth to aquifer ranges from 40 to 100 m with corresponding resistivity values that range between 150.0 and 350.0 Ωm in the region of the interconnectivity of lineament, which is the eastern part of the study area (Igboloye-Covenant University area) and had high groundwater potential. The western part which is void of the interconnectivity of lineaments (Alapoti area) ranges from 80 to 130 m with resistivity values that range between 250.0 and 450.0 Ωm suggesting that the area has low groundwater potential. The study, therefore, shows that the occurrence of groundwater in Ado-Odo/Ota community is a function of hydrogeological structures such as lineaments or fractures, and as a result, this information could serve as guide for borehole drillers, civil engineers and resident of the study area for proper planning before siting borehole either for domestic or industrial use.