Groundwater vulnerability assessment using a GIS-based DRASTIC method in the Erbil Dumpsite area (Kani Qirzhala), Central Erbil Basin, North Iraq

Groundwater vulnerability assessment is a crucial step in the efficient management of groundwater resources, especially in areas with intensive anthropogenic activities and groundwater pollution. In the present study, the DRASTIC method was applied using Geographic Information System (GIS) to delineate groundwater vulnerability zones in the Erbil Dumpsite area, Central Erbil Basin, North Iraq. Results showed that the area was classified into four vulnerability classes: Very low (16.97%), low (27.67%), moderate (36.55%) and high (18.81%). The southern, south-eastern and northern parts of the study area exhibited the highest vulnerability potential, while the central-northern, northern and north-western regions displayed the lowest vulnerability potential. Moreover, results of the single-parameter sensitivity analysis indicated that amongst the seven DRASTIC parameters, the unsaturated zone and the aquifer media were the most influencing parameters. In conclustion, the correlation of 25 nitrate concentration values with the final vulnerability map, assessed using the Pearson correlation coefficient, yielded a satisfactory result of R = 0.72.