Olumuyiwa O. Falowo
Abstract. The study focused on the hydrogeology of Erinjiyan Ekiti, southwest Nigeria, with major lithological units consisting of migmatite, granite gneiss, and older granite. The study involved electrical resistivity; hydrological studies; hydraulic measurement/estimation; borehole logging; and hydrogeochemical analysis. The results indicate runoff, runoff coefficient, and expected groundwater recharge to be 925 mm, 61.7%, and 300 mm respectively. The combination of KH and HKH are the dominant curve types accounting for 80.9% of the curve types. The weathered layer and unconfined/confined fractured basement are the major water bearing units, and more prolific where there is basement depression. The longitudinal unit conductance (0.04-1.76 mhos; avg. 0.3895mhos) and reflection coefficient (0.38-0.99; avg. 0.7929) suggest poor protective capacity and good groundwater prospect respectively. The yield capacity (0.64-1.99 L/s), hydraulic conductivity (0.32-0.95 m/d), transmissivity (1.92-16.71 m²/d) also suggest clay-sand mixture aquifer depicting a semi-permeable material. Hydrochemical facies of the groundwater fall within strong acids exceed weak acids, and where no one cation-anion pair exceeds 50%. The physical and bacteriological characteristics of the water were above standard maximum permissible limits for drinking water, while the chemical parameters are within standard specification. Most parts (46 %) of the study area are characterized by moderate potential water bearing units and cut across the entire north eastern part of the study area. The areas with good groundwater zones recommended for drilling is only feasible in the southern part with an aerial coverage of 10%. However, water treatment is highly expedient before drinking.
Keywords: Erinjiyan, Hydrogeochemical, groundwater, borehole logging, hydrogeology, contamination
Cite in Nipponpub Style:
Falowo, O.O. (2022). Hydrogeological Investigation of Erinjiyan, Ekiti State, Nigeria. Nipp. J. Environ. Sci., 3(1), 002