HYDROGEOLOGIC INVESTIGATION USING VERTICAL ELECTRICAL SOUNDING METHOD IN AGBARHA OTOR, DELTA STATE NIGERIA

Abstract

Vertical resistivity sounding measurements were conducted at fifteen(15) locations in Agbarha-otor in Ughelli North Local Government Area in Delta State using Schlumberger electrode configuration. The field data where interpreted qualitatively as well as quantitatively. Five basic geoelectric layers were delineated in the area such as topsoil, laterite, fine sand and medium-coarse grain sand with resistivity ranging from 257- 3873!m, 479-3022!m, 519-3071!m and 1137-3735!m and a depth ranging from 0.6-1.5m, 3.8-9.5m, 11.6-51.6m respectively. The result of the study shows that, at a depth of 5.1-51.6m lies the aquifer in the area with resistivity ranging from 990-3071!m and the thickness of the aquifer in the area was observed to be between 9.1-47m. The NE part of the region is prone to contamination from human activity such as landfill as a result of the shallow depth to the top of the aquifer. Portable water can be obtained from VES8 and VES9 in NE-SW direction of the study area due to aquifer thickness of 47m and 43m respectively.