Vol. 5(12), pp. 687-696, December, 2013
DOI: 10.5897/IJWREE2013.0424
ISSN 2141-6613 © 2013 Academic Journals
http://www.academicjournals.org/IJWREE
International Journal of Water Resources and
Environmental Engineering
Full Length Research Paper
Hydro-geoelectric study of Ijare town, southwestern
Nigeria
Oladapo, Michael Ilesanmi
Department of Applied Geophysics, Federal University of Technology, Akure, Nigeria.
Accepted 11 November, 2013
Geoelectric study involving fifty four (54) Vertical Electrical Soundings (VES) has been undertaken
within Ijare, southwestern Nigeria with the aim of evolving the hydrogeologic setting of the town. Ijare is
underlain by the Precambrian Crystalline Basement Complex rocks with inhabited parts of the town
underlain by migmatite gneiss and fine-grained biotite granite while inselbergs of older granites suites
adjoins the town on all sides. Based on the hydro-geoelectric characteristics obtained from geoelectric
sections and maps, the study area is classified into low, moderate and high groundwater potential
zones. Four geoelectric subsurface layers delineated from the study are the topsoil, weathered
basement, fractured basement and the presumably fresh bedrock. The concealed ‘basement complex’
morphology is rugged in the town with concealed ridges underlying the central areas while the eastern
and northwestern areas are underlain by irregular concealed depressions. The zones of concealed
basement depressions with resultant significant overburden thickness constitute target areas for
groundwater development in the town. Arising from the general classifications undertaken using the
results of the geoelectric soundings, sustainable groundwater development schemes for Ijare is
considered feasible on the eastern and northwestern flanks where groundwater potential rating varies
from moderate to high.
Key words: Geoelectric, groundwater, basement, ridge, depression, overburden, fracture.
INTRODUCTION
Over the years, potable water supply to Ijare community
in Ondo State Nigeria through surface supply scheme
has ceased due to non-functioning of the pipe-borne
water system. The community at the time of study relies
on water fetched from streams, ponds, shallow hand-dug
wells and a few and inadequate motorized boreholes.
However, the quality and wholesomeness of these water
sources (perhaps with the exception of the motorized
boreholes) are very much uncertain and many of the
populace stands the risk of infection through water borne
diseases. This is because the existing domestic water
sources are vulnerable to contamination arising from
disposal of refuse and faeces close to the
aforementioned water sources. Groundwater pollution through
human activities is considered worse than natural
pollution as it renders water less suitable for use than its
original state (Ishaku and Abdulhakeem, 2010; Abimbola
et al., 2005). Also, seasonal variations greatly affect the
quantity available from the sources significantly to the
extent that they sometimes dry up. In view of this,
groundwater development becomes a viable option for
portable water provision all year round for the Ijare
community. Thus, this study examines the hydrogeologic
setting within Ijare town with a view of hydro-geophysical
characterization of the town for future groundwater
development scheme that may be envisioned.
Delineation of areas of safe and adequate groundwater to
meet the general needs of inhabitants of Ijare town in
E-mail: oladapom@yahoo.co.uk