Groundwater Prospecting in Oru, Southeastern Nigeria Using Vertical Electrical Sounding Data

Abstract

Groundwater prospecting in Oru area, Southeastern Nigeria was carried out using Vertical Electrical Sounding (VES). The study area is located within the geographic coordinates: Latitude 5039IN to 5050IN and Longitude 6050IE to 6059IE. The aim of this work is to delineate the shallow aquifers from the deep zones. The study area is underlain by the Benin Formation which is within the Niger Delta Basin. Twenty-Seven (27) VES data were acquired using a Schlumberger array with a maximum electrode separation of AB/2=350 metres and interpreted using 2D-inverse interpretation resistivity software. The results revealed that the lithology of the area is mainly composed of sands and alternating sequence of clays and silts. The thickness of sands increases from Awo-Omamma to Ohakpu while it decreases towards Ura-Akatta and Amagu communities. Results show that the value of the apparent resistivity ranges from 2000?m to 22,000?m. The aquifer thickness in the study area varies from one location to another. In terms of depth of occurrence of the aquiferous layer/medium, there are shallow aquifers at Amagu and Amiri at 16m and 15m respectively; while at Ura-Akatta, Akwada-Aji, Ubachima etc, the aquifers occur at 32m, 39.9m and 38m respectively; but, at Umuokwe Awo-Omamma, Eziani-Mgbidi, Eziama-Ubulu, Umuezike Amadehi Oburu etc. the aquifers occur at 50.3m, 54m, 56.5m, and 63.5m respectively. Based on the information obtained from the resistivity models, it showed that the groundwater potential in the study area is very promising and prolific and this was based on the fact that the depth of occurrence of the aquifer and its thickness is large.

Keywords

References