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GEOPHYSICAL INVESTIGATION OF GROUNDWATER
RESOURCES IN OGUME AREA OF NDOKWA LAND DELTA STATE, NIGERIA.
Oseji, J. O.
Department of Physics,
Delta State University, Abraka,
Delta State
oseji2002@yahoo.com
ABSTRACT
Vertical Electrical Sounding
data were acquired from 7 locations evenly distributed within Ogume
communities. The apparent resistively values obtained in the field were
plotted against half current electrode spacing. Interpretation of data
were done both quantitatively and qualitatively and bringing in to bare
the knowledge of the local geology of Ogune. Based on the geoelectric
section, which shows the relationship between the drillers log and the
resistively measurements at common depth of penetration, there layers of
near surface aquifer that are not confined were identified in Ogume. It
is therefore recommended that boreholes for sustainable water supply
within Ogume and environs should be drilled to the fourth geoelectric
layer at a depth of 50.00m, while in areas within Obiogwa Ogbe-Ogume, a
depth of 80.00m is required and a minimum depth of 30.00m could be
sufficient for groundwater development in the rest part of Ogebe-Ogume.
These depts. Correspond to the third and best layer of aquifer in Ogume
and environs with a very good quantity of groundwater. The resistively
of this layer is between 1000.00
Ωm
– 4000.00
Ωm with an undefined
thickness since it is the last layer and it consist of medium-gained
sand formation. Although, the derivatives of clay seems to have
confining effects on the groundwater within Ogume and environs, the
concentration and thickness is not enough to act as a confining layer,
hence Ogume and environs has an unconfined aquifer, in the event of
pollution, groundwater may be easily contaminate.
KEY WORDS:
Groundwater potential, Vertical Electrical Sounding, Aquifer, Contour
map, Drillers log and Geoelectric Section. |
