Aquifer Upper-Middle Pleistocene (qp2-3) vulnerability assessment using origin DRASTIC and improved AHP- DRASTIC in Ho Chi Minh City

Abstract

Groundwater protection against anthropogenic sources, including the exploitation and use of groundwater sources, the release of wastes into the soil environment, changes in land cover, and the process of groundwater recharge is of paramount importance for protecting human health by securing clean groundwater for drinking water production. The identification of a groundwater contamination risk zone has been found to be a necessary and useful approach for managing this valuable resources. In the present study, the improved DRASTIC index model with optimized AHP weights technique applied for the assessment of groundwater vulnerability in the Upper-Middle Pleistocene aquifer of Ho Chi Minh City. The dataset of AHP weights of the DRATIC component parameters calculated from the data of experts' evaluation of the characteristics of the study area, demonstrates very clearly the importance of the component parameters of the study area. The results of GIS and AHP- DRASTIC have showed three levels: the low vulnerability zone is 60,98%, medium and high vulnerability zones account for 25,64% and 13,38% of the total study area, respectively. According to the level of vulnerable zoning, the highly vulnerable area is one that has exposed aquifers or shallow aquifer roofs, significant recharge (added directly from rains or runoff from the surface flows in associated with contaminants from runoff flows), coverage rates, and extensive mining activities constitute a high-risk index for groundwater vulnerability. This result suggests that the GIS-based DRASTIC index model is a useful tool to assist policymakers in formulating solutions for the sensible use of water resources, as well as to identify regions where groundwater exploitation is limited.