Hydrogeological and Groundwater Potential Studies Around Oke-Oyi Area, Sheet 202 Sw, South-Western Nigeria
1,* Issa, U., 1,Ajadi, J., 1,Jimoh, A.Y., 2,Ibrahim, K.O and 3,Magaji, Y.
1Department of Geology and Mineral Science, Kwara State University, Malete, Ilorin, Kwara State, Nigeria.
2Department of Geology and Mineral Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria.
3Department of Geophysics, University of Ilorin, Ilorin, Kwara State, Nigeria
DOI: 10.36108/laujoces/6202.61.0111
Abstract
Geology of an area can serve as a key factor in the understanding of its hydrogeology. The geologic and Hydrogeological studies of the Oke-Oyi area and its environs were carried out, aimed at analyzing the petrography of different lithologies encountered in the area as well as evaluating its groundwater potential. The study involves geological mapping through footpath traversing using appropriate mapping tools. Groundwater levels were measured from fifty hand-dug wells in the area using a weighted surveyor’s tape, and employed to generate seasonal groundwater level maps. The hydraulic properties of aquifers which include hydraulic conductivity, transmissivity and storativity in the area were determined from their pumping test data using calculation methods with appropriate formulae. The lithologies observed in the area were biotite-granites and metasediments with open and infilled joints trending mostly in the NE-SW direction. The produced hydrogeological maps interpreted that groundwater flows through the relief pattern of the area and the flow is largely in a north-east direction. The hydraulic conductivity, transmissivity and storage coefficient ranged from 1.17×10-1 m/day to 8.60×10-2 m/day, 0.95 m2/day to 3.16 m2/day and 0.619 to 1.765 respectively. The crystalline rocks in the area can produce modest groundwater potential. Groundwater movement in the area is controlled by its hydraulic head and permeability of the material through which it flows. The declination in water levels indicates groundwater flow direction. The average value for the storage coefficient of the area indicated that the storage potential of the boreholes is low; hence, their recharge potential is low. Enhanced storage potential of the available boreholes through deepening of the borehole structure and artificial recharge should be encouraged.
Keywords: Aquifer, Conductivity, Granite-Gneiss, Hydrogeology, Transmissivity