Evaluation of Groundwater Vulnerability to Pollution Using the DRASTIC Model and GIS in the Plain Part of the Khazir River Basin, Northern Iraq

Abstract

For its vastness and range of crops, the Khazir River Basin is an important agricultural region. Since groundwater supplies domestic and agricultural water, it is heavily pumped there. This study maps groundwater contamination risk and identifies high-risk locations. GIS was utilized for computations and producing maps of vulnerable water-bearing units. The most influential factors that play a major role in groundwater pollution have been considered and are the heart of DRASTIC model. A Digital Elevation Model (DEM) of 30 meters resolution was used to create the slope map (Topography map) of the area. Due to the fact that the land in the study area is intensively utilized for agricultural purposes where fertilizers are always used for improving crop production, two types of DRASTIC models have been run, i.e., under two scenarios, one as a standard, following as (S-DRASIC) and the other as a pesticide DRASTIC approach denoted as (P-DRASTIC). The results clearly show that the areas of; shallow groundwater depths, porous aquifer media, highly permeable soil media, low slope terrains, thin and permeable vadose zone, and finally an aquifer of high hydraulic conductivity reveal high vulnerability to contamination.