Hydrogeophysical Studies for the Delineation of Potential Groundwater Zones in Enugu State, Nigeria

Abstract

This report discusses the occurrence of groundwater in Enugu State, Nigeria, as indicated by results of 322
vertical electrical soundings(VES), supplemented by 123 well records. The project area lies within Longitudes
7° 6’ E - 7° 54’E and Latitudes 5°56’N- 6 °52’N, and covers an area of about 7161km
2
over eight main geological
formations. The thickness, lateral extent and transverse resistance of the aquiferous layers were determined
by the electrical survey. Water table information from borehole records was used to construct regional maps
of static water level depths and groundwater flow directions. The results show greater depth of the substratum
in the central part of the study area as indicated by high transverse resistance and thickness of the aquiferous
layers. Lower average values of these parameters were obtained in the southwestern and eastern parts of the
study area. Specific discharge and average linear groundwater velocity follow similar trend, generally
improving from the western and eastern parts to the central part of the study area. Regional maps of the
various geoelectrical and hydrogeological parameters have been produced and the overall results have been
used to delineate the study area into five groundwater potential zones for future development and choosing of
drilling sites.