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Geo-electrical Resistivity Evaluation of Groundwater Potential at University Of Benin Ugbowo Campus, Benin-City, Edo State of Nigeria, Using the Schlumberger Array
BASSEY, P; LAWRENCE, OO & AILEGO, J
Abstract
Geo-electrical resistivity survey was conducted in part of the University of Benin, Benin-City, Ovia
Northeast of Edo State, Nigeria, with a view to establishing the most dependable aquifer bearing zone and the lateral and
vertical variation of subsurface lithology with distance and depth respectively. In this study, the schlumberger electrode
configuration was employed for the acquisition of VES data in the field. A total of 6 VES stations were engaged within
the study area. A, H and HK resistivity curve types were identified, reflecting facies or lithological variations in the area.
Three patterns of geo-electrical resistivity curves obtained using IP2WIN software can be associated with different rock
formations in the study area. Dar Zarruk Parameters were tools used for aquifer characterization in determining the
groundwater potential of the area and capacity bearing rating, viz: Total transverse resistance (T) and Total longitudinal
conductance (S), Resistivity Contrast (RC) and Resistivity Reflection Coefficient (RRC). Results obtained shows that
VES 1 (coordinate N6o 23’56.69’’, E5o 37’ 32.83’’) with four layers and an A curve type is the most potential source for
groundwater compared to other VES points. It is a sandy clay layer of resistivity 198Ωm, with thickness to infinity and
well confined at the top by a laterite layer. VES 1 has the highest Total Traverse Resistance 690310 Ωm2 (showing a very
good transmmitivity of the layer), Resistivity Contrast (0.01) and Resistivity Reflection Coefficient (0.90), all parameters
falling within good prospect for groundwater development, but has a Total Longitudinal Conductance (S) value of 0.002
mho which shows that VES 1 has a poor bearing capacity. In summary, the results of the geo-electrical resistivity survey
conducted at the Vice Chancellor’s Lodge area of University of Benin using Schlumberger Array, revealed the most
dependable aquifer bearing zone and the lateral and vertical variation of subsurface lithology with distance and depth
respectively.
Keywords
Geo-electrical Resistivity; Aquifer; Subsurface Lithology; Benin-City
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