Delineation of aquifer systems and aquifer vulnerability using geoelectrical parameters: A case study of Ashaka cement factory

Abstract

The rapid growth of population in the sub-Sahara Africa, coupled with increasing industrial activities leads to greater demand for safe water for domestic use. Thus, aquifer system and vulnerability studies is of paramount important and a responsibilities of current researchers. This study intends to delineate aquifer systems and aquifer vulnerability using geoelectrical parameters around Ashaka cement industry. The Ashaka area is part of the Gongola Sub-basin of the Upper Benue Trough that include sandstone, shale, and limestone. The oldest stratigraphic units is Bima Formation which occurs on the floor and is overlain by Pindiga Formation. To delineate the aquifer systems and evaluate the vulnerability of aquifers around the research location, 35 Vertical Electrical soundings were undertaken. The Vertical Electrical Soundings measurements results suggests a maximum of five geo electrical layers which indicates that the aquiferours layer lies between fourth to fifth layers. The transmissivity values ranges from moderate (110.137 m2/day) to high (893.57 m2/day) potentials and the hydraulic conductivity ranges between 4.551 m/day and 29.789 m/day with an average of 17.650 m/day. Correlation of borehole lithology with the interpreted lithologies from the VES revealed that the aquifer systems are unconfined to semi-confined, consisting of sandstone and weathered limestone of various thicknesses. Longitudinal conductance was computed to evaluate the aquifer vulnerability which shows values ranging from between 0.20701 and 1.43308 with an average of 0.75298, and thus indicates that the area is free from surface contamination having moderate to good aquifer protective capacity.