Aquifers Characterization in Agaie, North-Central Nigeria Using Electrical Resistivity Method and Borehole Lithologs

Abstract

The aquifer systems in Agaie area, North-Central Nigeria have been characterized using electrical resistivity technique and borehole lithologs. Electrical resistivity techniques of geophysical survey were used for data generation through Schulumberger and Wenner configuration. The acquired data were subjected to manual and computer aided interpretation methods which enabled the delineation of the lithological sequence of the subsurface. A total of nineteen boreholes were drilled and systematically logged during the drilling process. The geoelectric sections were overlaid with lithological logs and the result used in the characterization of the aquifer in the area. Information obtained from 98 hand-dug wells inventory and 19 drilled boreholes were used to supplement the geophysical investigation. The study revealed area with shallow and deep wells in relation to the groundwater flow direction of NE and SW corresponding to high groundwater potential while the southern portion of Agaie has medium groundwater potential. The geoelectric section and lithologs obtained presents two aquitards (sandy-clay and clayey-sand) and sandstone aquifer with fine to medium grained. The failure of most boreholes in the area was the inability to delineate aquifer from aquitard in the area. A minimum depth of 50-60m was recommended for borehole and 20-25m for hand-dug well in the study area. Siting of boreholes and hand-dug wells away from soakaway, toilet and dumpsite is advocated. Good hygiene practice is also suggested for the people of the area to avoid water borne disease in the future.