Depiction of Aquifer plausible zones and protective capacity using hydraulic parameters in Modomo/Kajola, Ile-Ife, Southwestern, Nigeria

Abstract

This study is intended at depicting the aquifer plausible zones in Modomo/Kajola, Ile-Ife using Dar Zarrouk parameters. The study area is situated amid latitudes 830,00–830,500 mN and longitudes 663,500–664,000 mE, overlying pegmatite and granite gneiss in the basement complex terrain. Twenty-eight (28) Schlumberger-array vertical electric soundings (VES) were carried out within the study area with the help of Terrameter SAS 300C. The VES interpretation result reveals three to five geo-electric layers: topsoil, clay/sand/lateritic layer, weathered layer, fractured basement, and fresh basement. The geoelectric sections showed the main aquifers to be unconfined, semi-confined, and confined composed of sandy clay, clayey sand, and sand with different thicknesses (aquifer thickness varying from 3.3 m to 15.8 m with a mean value of 9.9 m). The aquifer hydraulic characteristics show that the longitudinal conductance (L) varies from 0.014 Ωm to 1.000 Ωm with a mean value of 0.132 Ωm, the transverse resistance (T), varies from 677.4 Ωm2 to 6465.7 Ωm2 with a mean value of 2291.2 Ωm2. The Hydraulic conductivity (K) values vary from 29.4 m/day to 126.9 m/day with a mean value of 50.5 m/day. The transmissivity (Tr) values attained at many layers vary from 418.7 m2 /day to 465.1 m2 /day, with a mean value of 449.4 m2 /day. The GSLI values vary from 2.25 to 4.25 with a mean value of 2.9. Three aquifer plausible zones were depicted involving sandy clay, clayey sand, and sand.