The impact of certain unregulated land-use activities harms the quality of water resources and reduce the sufficiency of drinking water in many developing countries. This study aimed to capture the impact of such activities and evaluate the specific groundwater vulnerability using a modified DRASTIC approach. The DRASTIC-LuPa was proposed and implemented for Aba City, Nigeria by incorporating land-use and the impact of pumping layers to the “intrinsic” DRASTIC parameters. The results of the analysis revealed that the area classified as “low” was 15%, 79.1 % as “medium” and 5.9 % as “high” vulnerability classes for the DRASTIC. Whereas for the DRASTIC-LuPa model 3.2 % for “low”, 54.3 % for “medium”, 41.8 % for “high” and 0.7 % for “very high” were found. The transitions in the vulnerability classes of areas displaying “high” and “very high” found in the DRASTIC-LuPa model represent the impact of urban hotspots observed in the area. This result implies that groundwater protection measures should be implemented in the area designated with “low”, and “medium” vulnerability classes and used for abstracting clean water for drinking purposes. The proposed model enhances the predictability and guarantees better transferability of the approach in urban settings with similar urban trends.
Keywords: Drinking water, DRASTIC, Groundwater, Groundwater vulnerability assessment, Nigeria