Abstract:
Geophysical investigation involving the use of Electrical Resistivity method using Modified
Wenner Array Configuration has been adopted for shallow groundwater potential evaluation
over a floodplain at AULE, Akure southwestern Nigeria for irrigation purposes. The research
presents the result from the quantitative interpretation of forty eight vertical electrical sounding
(VES) obtained from the survey area which has helped in the identification of aquiferous units
and has provided an understanding of aquifer characteristics especially the thickness and depth to
fractured zones which are required for locating points with high potentials for groundwater
occurrence. The Vertical Electrical Sounding technique result delineated three to six (3-6)
subsurface geologic layers (top soil, clay, clay, weathered layer, partly weathered layer and
bedrock) with different depth ranges (0.04m to 10.0m). The lithology of the subsurface strata is
mainly clay (expansive clay) which justifies the dominance of low resistivity values and explains
why the runoff water via flood doesn’t infiltrate the soil. The overburden thickness and aquifer
resistivity were used in classifying the groundwater potential of the study area. Areas having
moderate overburden with thickness between 5m and 10m with weathered layer above 4 ?m
such as VES 1, 3, 13, 28, 32, 39, 40, 41, 43 and 44 are delineated to be promising sites for
shallow wells. |
