Determination of the Groundwater Potential of Parts of Makurdi Sheet 251 SW, North Central Nigeria, Using Electrical Resistivity Method

Abstract

An integrated geological and geophysical studies were carried out to investigate the groundwater potential in part of Makurdi, North Central Nigeria. The schlumberger array was used for the geophysical investigation with a maximum AB/2 of 100m. A total of 20 Vertical Electrical Sounding (VES) stations were established. The model curve types obtained from the resistivity plots include Q, A and H curves. The study area constitutes three to four major lithologic units comprising the topsoil (laterite, clay or loose sand) and the subsequent layers comprising of either sandstone, clayey sandstone, clay or sandy clay. The best of these units as regards to groundwater potential is the uniform sandstone unit owing to its effective porosity and permeability. Isoresistivity maps at depths of 20, 30 and 50m respectively were generated and revealed that a dominant part of the study area has a very good groundwater potential at shallow depths of about 20 – 30m; while at a depth of 50m, only the North-Eastern and South-Eastern parts of the study area have a good groundwater potential. A groundwater potential map was generated at the end of the study dividing the study area into high, moderate and low groundwater potential zones denoted as A, B and C respectively on the map