Assessment of Groundwater Potential in Ehime Mbano, Southeastern Nigeria

Abstract

The electrical resistivity method involving vertical electrical sounding procedure was employed in assessing the groundwater potentials of Ehime Mbano area with the aim of delineating aquifer for sustainable groundwater development. Over sixty vertical electrical sounding were acquired within the study area using the Schlumberger electrode configuration. The results show relatively less resistive northern portions and highly resistive southern parts based on the contrast in geoelectrical values. Occasional truncation of lateral continuity of the sands and sandstones by shaly sediments were observed around the southern parts of the study which influences groundwater circulation and may constitute a factor hindering the even distribution of groundwater resources in the area. Based on the results of the inverted resistivity models the depth to aquifer should be >90 m. The sands at this depth have the capacity to permit groundwater circulation. Dar Zarouk parameters were estimated and the results mimicked the geology of the area. Longitudinal conductance values were low in the southern portion dominated by sands and sandstones while the northern portion possessed high values of longitudinal conductance resulting from clays and shales. On the contrary, the transverse resistance show higher values in the northern part. Based on the sands and sandstones that dominate the southern portions and the values of the aquifer parameters estimated in the southern parts favours groundwater circulation and possesses good groundwater exploration prospects.