Estimation of Groundwater Potential and Aquifer Protective Capacity Within Old Ikenga Hotel, Nsukka, Enugu State, Nigeria.

Abstract:

A geophysical survey using electrical resistivity method was conducted around Old Ikenga Hotel, Nsukka in Enugu State, Nigeria to investigate the groundwater potential and aquifer protective capacity of the area. The project area lies within latitudes 6°50'4.0''N - 6°57'52.0"N and longitudes 7°21'6.3"E - 7°28'12.0"E, and covers an area of about 89.6 km2. Vertical Electrical Soundings (VES) were carried out with a digital read out resistivity meter (ABEM SAS 1000). The VES points were marked at 25 m and 75 m along a 100 m line. A total of eight soundings were carried out in the area. The VES data collected were interpreted using INTERPEX software and the results presented in terms of resistivity, thickness, depth and lithology. The lithology was inferred by correlating the result to the lithology log of the borehole drilled in the hotel and the geology of the study area. The VES result shows lithologic layers varying from 4 to 5. Aquiferous sand and Aquiferous sandy shale constitute the aquifer units in the area at depth of 30.26 m to 188.20 m, with their thickness ranging from 30 m to 74 m as shown by their isopach map. The aquifer protective capacity was determined by calculating for longitudinal conductance and matching the values to known standards. The calculated longitudinal conductance varies from 0.0409 to 3.1235 mhos. The interpreted VES results reveal poor, moderate, good and very good aquifer protective capacities of the overburden layers.