Application of Three Electrical Resistivity Arrays to Evaluate Resolution Capacity of Fractured Zones at Apatara Farms, Iwo, Osun State, Nigeria
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Date
2017
Authors
Adeoti, L
Afolabi, O.S
Ojo, A
Ishola, S.K
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Applied Sciences and Environmental Management
Abstract
The study applied three different electrical resistivity arrays (Wenner, dipole-dipole, and Pole-dipole)
based on their resolution capacity to delineate fractured zones at Apatara Farm in Iwo, Osun State, Nigeria. Theoretical
apparent resistivity data were computed for each model and contaminated with 5% Gaussian noise as a further
concession to real field conditions. The simulated results revealed that the Wenner array gave the least error in trying to
reconstruct the true model when the fractured zone is placed near the subsurface. However, when the fractured zone is
placed at a depth beyond 5 m, the Dipole-Dipole array gave a better resolution than Pole-Dipole and Wenner array in
decreasing order of resolution. The study further revealed that the Wenner array is less susceptible to edge effect at
shallow depth while Dipole-dipole is more susceptible to edge effect at deeper depth followed by the Pole-dipole array.
2D electrical resistivity field measurements were carried out to confirm the results of the numerical simulation in the
same field using the same parameters. The inverted resistivity images showed that the fractured zones are well
delineated by the Dipole-dipole and Pole-dipole arrays but poorly resolved by the Wenner array. The study has
demonstrated the usefulness of numerical modelling for imaging of fractured zone necessary for hydrogeological
purpose and through modelling, the user has unlimited power to image or simulate a real-world scenario seamlessly
before carrying out the actual field survey.
Description
Keywords
Electrical resistivity array , fractured zones , finite element method , 2-D models , resolution , mean absolute error
Citation
Adeoti, L., Afolabi, O. S., Ojo, A., & Ishola, S. K. (2017). Application of Three Electrical Resistivity Arrays to Evaluate Resolution Capacity of Fractured Zones at Apatara Farms, Iwo, Osun State, Nigeria. Journal of Applied Sciences and Environmental Management, 21(6), 1213-1221.