Application of Vertical Electrical Sounding Technique to Evaluate Aquifer Transmissivity in Amawbia and Its Environs, Awka South, Nigeria.

The DC electrical resistivity measurement employing Schlumberger electrode configuration was used to estimate the transmissivity of aquifer in Amawbia and its environs, Southeastern, Nigeria. Vertical electrical sounding (VES) data were collected at four different locations with maximum current electrode spacing of 600 m. The interpretation was done using software called IP2win. The result revealed that the lithology of the area comprised mainly of laterite, clayey sand, dry sand, shale and saturated sand. The result revealed that the first layer resistivity and thickness ranged between 284.30 and 1313.5 Ωm and between 2.29 m and 2.54 m. The resistivity and thickness of the second layer ranged between 87.87 and 1726.81 Ωm and between 1.57 m and 8.79 m. The third layer resistivity ranged between 15.57 and 1520.66 Ωm while the resistivity and thickness of the aquiferous layer ranged between 663.39 and 1528.17 Ωm and between 22.11 and 29.39 m respectively. The layer parameters (resistivity and thickness) obtained from the interpretation of the data were used to compute the longitudinal conductance and transverse resistance. Data analysis was done with the relationship between aquifer characteristics and Dar-Zarrouk parameters to obtain the transmissivity values. The calculated transmissivity values ranged from 4.12 to 9.63 m2/day.