Investigation of Aquifer Vulnerability in Damaturu Using Electrical Resistivity Method

Abstract

Agada Livinus Emeka  and Saleh Mustapha Babagana

The rapid growth in anthropogenic activities in both cities and rural areas has contributed immensely to aquifer vulnerability. Aquifer vulnerability has a significant impact on groundwater quality, groundwater recharge status and the vadose zone. Different geological environments may have diverse statuses of aquifer vulnerability. Therefore, to provide baseline information on aquifer vulnerability regarding Damaturu, the present study was designed to investigate the vulnerability of aquifers in Damaturu. The study area consisted of five geologic layers, which included the topsoil, clay, sand, sandy-clay and sand. Two aquifers were delineated in the study area. The first Aquifer was unconfined in some parts of the study area and it is also semi-confined in some parts of the study area. The first Aquifer is overlain by thin overburden units, which were not thick enough to protect it from invasion by infiltrating contaminants from the surface. The second Aquifer is confined by a thick sandy-clay formation with an appreciable thickness which enables it to possess quality groundwater.   The longitudinal conductance of the first Aquifer in the study area ranged from 0.53 to 1.45 mΩ^-1, with an average value of 0.93 mΩ^-1. It is shallow and has an average depth of 50 m. The aquifer protective capacity was 93% good and 7% moderate. These results clearly showed that the first Aquifer in the study area is vulnerable to contamination by leachate and any other percolating fluids. The second Aquifer is overlain by a thick sandy-clay formation which protects it from pollution by leachate. It is the most appropriate for quality groundwater abstraction in the study area. Due to the proximity of the first Aquifer to the surface, there is a need for regular monitoring of the groundwater to protect it from pollution. A proper groundwater monitoring system is imperative in the study area to protect the population from the dangers of consumption of contaminated water.