GEO-ELECTRICAL DELINEATION FOR GROUNDWATER RESOURCES OVER GIDAN-DOYA BASEMENT AREA, CENTRAL NIGERIA
Abstract:Groundwater development
is very important in the survival of the human. This research was carried out
in a newly developing area with population increase and agricultural
development hence the need for this study. The objective is to carry out a
geophysical investigation, delineate aquiferous zones, and groundwater
potential for the study area. An electrical resistivity method for groundwater
investigation using the Vertical electrical sounding (VES) technique was adopted.
The survey involved three profiling and seven VES points using the Schlumberger
configuration to delineate the subsurface lithologies and aquiferous zones
within the study area. It was observed that the study area is composed of
highly weathered and fractured rocks; hence there is a tendency for groundwater
migration and accumulation in the weathered fractured horizons. Two geo-electric
sections and a basement map were produced. The area generally showed four to
five lithology units; which include topsoil, laterite, weathered basement,
fractured basement, and the fresh basement. The thickness of the overburden
ranges from 0 - 12.8m and the saturated layers have resistivity values ranging
from 19.7Ωm - 849.8Ωm with depths to water range of 10.5m – 61.1m respectively.
VES points 2, 4, and 5 showed good potential
for groundwater with aquiferous unconfined zones ranging depths of about 45.0m -
60.0m. It was also deduced that areas, where thick overburden complemented with the presence of weathering and
fractures within the study area, are
zones for groundwater accumulation.