DETERMINATION OF WATER BEARING FORMATION

ABSTRACT

Electrical resistivity tomography surveys have been conducted to pinpoint and outline underground water resources while estimating their reserves. These surveys primarily measure and map the resistivity levels of subsurface materials. The Electrical Resistivity Survey method proves to be a suitable technique in areas with complex geological conditions where traditional resistivity sounding and other methods are inadequate for providing detailed subsurface information. The objective of the Electrical Resistivity Survey is to assess the distribution of subsurface resistivity by taking measurements at the ground surface. For this study, resistivity imaging measurements were conducted using the Dipole-dipole Electrode configuration, employing the ABEM SAS 1000 Terrameter and Electrode selector system ES464. The results obtained from this dipole-dipole array survey unveiled lateral variations in subsurface lithology concerning both distance and depth. Traverse six clearly show that the resistivity ranges from 194Ωm to about 2563Ωm with a depth of 50m.The computer interpretation of the observed curve resolved the penetrated rocks at the site into (4) geo-electric layers.The first layer resistivity value is 257Ωm with a depth of 0.3m is interpreted as Topsoil;the second layer resistivity value is 983Ωm of 1.2m is sand;third layer with a resistivity value of 719Ωm at a depth of 24m is Lateritic sand; while the fourth layer with Resistivity value of 3118.3Ωm at a depth of 130.60m is Dry sand,the water table is not suspected on this profile.