2-D Electrical Resistivity Imaging to Delineate Groundwater Aquifer In Ijebu-Igbo, Southwestern, Nigeria
DOI:
https://doi.org/10.46881/ajsn.v4i0.79Keywords:
Aquifer, Dipole – dipole configuration, fractured basement, Groundwater, Weathered zoneAbstract
Groundwater aquifer mapping is a scientific process, where in a combination of geologic, geophysical and hydrologic analyses are applied to characterize the quantity, quality and sustainability of groundwater in aquifers. The non-availability of good water supply to Ijebu-Igbo prompted this research work using electrical resistivity method to characterize the groundwater aquifer in the study area. A total of six profiles of 2-D electrical resistivity imaging technique with length varying from 240m – 320m were carried out, and it involves the dipole-dipole configuration. The 2-D inverse models of resistivity variation with depth carried out suggest the occurrence of potential aquifers mostly in weathered/fractured zones within the profile lines. The pseudo section of the inversion results shows two profiles with saturated fractured basement where adequate groundwater can be obtained. From the results of the 2-D electrical resistivity imaging, an Iso-Pach map of depth to basement shows the peak and high contour closures revealed around profile lines five and six. This suggests that the basement is deeper than the other areas as evident in the relief pattern of the area which gives good groundwater potential zone. The low closures revealed suggest that the basement is closer to the surface around profile lines one and two, with small overburden thickness interpreted as poor groundwater potential zone.
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