Research Article: Open Access Internatonal Journal of Earth Science and Geophysics VIBGYOR ISSN: 2631-5033 Citaton: Bayowa OG, Ogungbesan GO, Mudashir AW (2019) Geophysical Investgaton of Oba Earth-Fill Dam Embankment using Electrical Resistvity Method. Int J Earth Sci Geophys 5:027 Accepted: October 22, 2019; Published: October 24, 2019 Copyright: © 2019 Bayowa OG, et al. This is an open-access artcle distributed under the terms of the Creatve Commons Atributon License, which permits unrestricted use, distributon, and reproducton in any medium, provided the original author and source are credited. *Corresponding author: Bayowa OG, Department of Earth Sciences, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria, Tel: +2348030820291 Bayowa et al. Int J Earth Sci Geophys 2019, 5:027 Geophysical Investgaton of Oba Earth-Fill Dam Embankment using Electrical Resistvity Method Bayowa OG * , Ogungbesan GO and Mudashir AW Department of Earth Sciences, Ladoke Akintola University of Technology, Nigeria Abstract Contnual post-constructon checks on dam embankment are inevitable to forestall the possi- ble catastrophes associated with its structural failure. In view of this, electrical resistvity (ER) surveys involving vertcal electrical sounding (VES) and dipole-dipole profling were conducted along the Oba dam embankment as a part of routne deformaton monitoring for any possible seepage(s) around the dam embankment. Thirty-one vertcal electrical soundings and thirty-fve dipole-dipole horizontal profling data were carried out on a 350 m long (west-east trending) traverse established along dam embankment. The iterated VES curves were mainly KH-type suggestng that Oba dam embankment is underlain by four geoelectric layers; topsoil (caprock), fll (granite materials), core (plastc-clay/wet clay) and basement bedrock with resistvity val- ues range of between 53-249 Ωm, 205-1084 Ωm, 15-124 Ωm and 281-1375 Ωm, respectvely. The dipole-dipole 2-D resistvity structure along the dam embankment showed no evidence of structural distress/weakness within the underlying sequences. Therefore, by integratng results obtained from geoelectric secton and 2D resistvity structure based on the layer resistvity/ lithological compositon of the core materials (15-124 Ωm/plastc clay/clay/sandy clay), Oba earth-fll dam embankment integrity was good to very good indicatng no seepage zone(s). Keywords Geophysical, Electrical resistvity, Oba rarth-fll dam, Embankment, Ogbomoso ous bedrock overlain by a less impervious caprock [1]. The Oba dam which is the focus of the present study is an example of an earth-fll dam. Oba earth-fill dam was constructed in 1964 with a view to supplying the inhabitants of Og- bomoso and its environs potable water through a well-designed waterworks plants established close to the dam. The Oba reservoir (lake) de- rives its water content from river Oba in the area (Figure 1). The waterworks with expected life Introducton Dams are structures that prevent the fow of water and get it accumulated in a reservoir, river or stream, etc. Dams can be constructed from con- crete, stones, masonry, loosed rock, earth wood, metal, or a combinaton of these materials. Hence, gravity, butress and arch dams are possibly built. Earth-fll dams are examples of gravity dams which cosist of an impervious core made up of imperme- able earth materials such as clay overlying impervi- DOI: 10.35840/2631-5033/1827