Investigation of Dam Integrity from Electrical Resistivity Methods: A Case of Erelu Dam, Southwestern Nigeria

Authors

  • Nurudeen Kolawole Olasunkanmi Department of Physics and Material Science, Kwara State University, Malete, Kwara State,, Nigeria
  • L.A. Sunmonu Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso, Oyo State,, Nigeria
  • D.T. Owolabi Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso, Oyo State,, Nigeria
  • M. Bawallah Department of Applied Geophysics, Federal University of Technology, Akure, Ondo State,, Nigeria
  • Azizat Oyelami Department of Water Resource Management and Agro-meteorology, Federal University, Oye-Ekiti,, Nigeria

DOI:

https://doi.org/10.17014/ijog.8.2.265-274

Keywords:

Water supply, seepage, geologic structures, reservoir level, dam failure.

Abstract

DOI:10.17014/ijog.8.2.265-274

Erelu dam is geologically within the Precambrian Basement Complex of southwestern Nigeria, which serves a principal source of water supply to an increasing population; currently at about 779,318. In an attempt to investigate the integrity of the dam, horizontal resistivity profiling (HRP) of dipole-dipole and Schlumberger’s vertical electrical sounding (VES) approaches were explored to delineate the lithologic layers, facies, and geologic structures in the subsurface of the dam. The HRP revealed changes in subsurface conductivity that depicts lateritic hard pan and saturated rock blankets at shallow depth. The vertical geo-electric section delineated predominant four lithologic units. The regolith is 7 m thick and constitutes the vertical rock fill impervious cores of the dam, which is underlained by saprolitic and fresh bedrock. The region of weathered rock depression coincided the shallow saturated anomalous zone and showed surface manifestation of fractured or unconsolidated terrain within the embankment. The fracture serves as conduit for seepage which could be responsible for possible loss in the reservoir water and increases its susceptibility to failure. It is recommended to keep monitoring the seepage with reservoir levels, by periodical geophysical and geotechnical measurements for the two (dry and wet) seasons.

Author Biography

Nurudeen Kolawole Olasunkanmi, Department of Physics and Material Science, Kwara State University, Malete, Kwara State,

Physics and Materials Science Department

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Published

09-07-2021

How to Cite

Olasunkanmi, N. K., Sunmonu, L., Owolabi, D., Bawallah, M., & Oyelami, A. (2021). Investigation of Dam Integrity from Electrical Resistivity Methods: A Case of Erelu Dam, Southwestern Nigeria. Indonesian Journal on Geoscience, 8(2), 265–274. https://doi.org/10.17014/ijog.8.2.265-274

Issue

Vol. 8 No. 2 (2021)

Section

Articles

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IJOG as the journal holds copyright of the published papers.

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