DELINEATION OF QUATERNARY AQUIFER USING VERTICAL ELECTRICAL SOUNDING (VES) IN OGBIA AREA, BAYELSA STATE, NIGERIA
Abstract
Electrical resistivity method using the schlumberger configuration were employed to delineate the quaternary aquifer in Ogbia area of Bayelsa State, Nigeria. The aim of this research is to determine the viability of the aquifer for borehole drilling. 10 VES points were carried out in Ogbia Area. They were interpreted by the use of IP12Win software. The interpreted VES data revealed 4-5 delineated layers of silty-clay, clay, clayey sand, sandy-clay, fine to coarse sand. Five sounding curve types were identified in the study area and they are of the KA, HA, QH, AK, and HKH types. The 4-layer geo-electric section were dominant compare to the 5-layer. The first aquifers were delineated at average depth of 24m and 34m with thicknesses ranging from 9.2m to 26.5m and resistivity ranging from310 to 8254Ωm while the 2nd aquifer were delineated at average depth of 37m to 43m with thicknesses ranging from 19.2m to 27m and resistivity values ranging from 740 to 9086Ωm. The second aquifer in the area are more reliable as sources of groundwater because they are less vulnerable to infiltration of surface contaminants and as well as possess better indices for higher groundwater yield due to their texture and greater thickness when compare to the first aquifer.