Assessment of Aquifer Vulnerability and Soil Corrosivity in Enugu and Environs, Southeastern Nigeria: Insights from Geo-Sounding Data

This study evaluates the vulnerability of aquifers in Enugu and its surrounding areas to contamination, using the IEC, GOD, and DRASTIC models. Additionally, soil corrosivity is assessed through resistivity measurements from 85 soundings conducted with the ABEM 4000 Terrameter. The IEC model classifies 88% of the area as extremely high vulnerability, 5% as moderate to high vulnerability, and only 1% as low to extremely low vulnerability. In contrast, the GOD model indicates that 60% of the area falls within the extremely low vulnerability category, 33% in the low vulnerability category, and 7% in the moderate vulnerability category. According to the DRASTIC model, 31% of the area is categorized as low vulnerability, 67% as moderate vulnerability, and 2% as high vulnerability. These combined findings suggest that the aquifer system in the study area has a low protective capacity, making it highly susceptible to contamination. In terms of soil corrosivity, 78% of the area is characterized as practically non-corrosive, with strata ranging from moderately to highly competent. Thirteen percent of the area shows slight corrosivity, corresponding to moderately competent to incompetent strata, while the remaining 9% exhibits moderate to very strong corrosivity, indicating incompetent strata. The study highlights the critical need for ongoing monitoring and management of groundwater resources in areas with varying levels of vulnerability and diverse soil characteristics.