Effectiveness of geophysical assessment of boreholes drilled in basement complex terrain at Afe Babalola University, using Electromagnetic (E.M.) method

In this research, an Electromagnetic (E.M) method of groundwater investigations was used as an on-spot assessment tool to test the integrity of the  developed borehole in Afe Babalola University, Ado-Ekiti. Some randomly selected functional and abandoned boreholes developed by the Vertical Electrical Sounding (VES) methods were chosen for this study, with the aim to know the potential of the boreholes. Four transverses were  established across the institution consisting of two functional and two abandoned boreholes selected from the existing forty boreholes. These weresubjected to E.M method of groundwater investigation using a PQWT S500 series machines. The results obtained from this study produced curve graphs and subsurface profile maps of each transverse location. It was observed that boreholes TR 1 and TR 3, were accurately sited on vertical fractures and weathered formations while TR 2 and TR 4 were wrongly sited at the locations of poor groundwater yielding zone. Keywords: Electromagnetic, Vertical electrical Sounding, transverse, Groundwater