Geophysical Determination of Water Bearing Formation Using 2-Dimensional Geo-Electrical Resistivity Imaging in Ologbo Area of Edo State

Abstract

Abstract
2-Dimensional Geoelectrical Resistivity Imaging Survey was carried out to locate water bearing formation at Ozolua road (line 12) and Lonestar area (line 19) in Ologbo, Ikpoba-Okha Local Government area of Edo State, Nigeria. Wenner – Schlumberger Array was carried out to map the electrical properties as an aid to characterizing the subsurface conditions using Petrozenith Earth Resistivity Meter. A total of seventy-eight soundings were obtained in each of the areas and the field data was processed and inverted using zondres2d software to obtain 2-dimensional true resistivity of the subsurface. In the first profile, the resistivity range lies between 350 to about 10000 Ωm, indicating variation in soil matrix, grain size distribution and water saturation. The decrease in resistivity at a depth below the top soil along the bottom right of the profile indicates the presence of saturated soil. In the second profile, the study reveals the range of spatial distribution of sand deposits with large quantity of gravel indicated by high resistivity of about 10000 Ωm. The resistivity of the study areas suggest that the near surface materials comprises of coarse sand and gravel while the underlying deeper materials also has high resistivity values. The resistivity values of the models probably indicates presence of water bearing formation in the survey area at greater depth of penetration. It is suggested that more research should be carried out so as to probe deeper into the formation in other to get to the aquifer table.
Keywords: 2D resistivity imaging, pseudosection, water, Ologbo

Cite this Article
Esangbedo J, Adagbon JE. Geophysical determination of water bearing formation using 2-dimensional geo-electrical resistivity imaging in ologbo area of edo state. Research & Reviews: Journal of Physics. 2015, 4(3): 11–22p.