Groundwater is one of the most important sources of drinking, industrial, and agricultural waterin arid and semi-arid regions, where the occurrence of droughts, rapid population growth, and thecorresponding increase in water demand threaten groundwater resources. Over-exploitation andmismanagement of groundwater resources result in environmental problems such as subsidenceand saltwater intrusion in coastal aquifers. The risk of saltwater intrusion threatens the Urmiaaquifer due to the proximity of the aquifer to Lake Urmia and severe groundwater decline. Thisstudy evaluates the vulnerability of saltwater intrusion by the GALDIT framework. The resultsshow the conservative vulnerability index with low efficiency, where vulnerable areas are limitedto a narrow strip near the coastline. Fuzzy membership functions were employed within theGALDIT framework to increase efficiency. The results of the modified GALDIT resolve theweakness of presenting conservative results in the basic GALDIT framework.
