Groundwater Vulnerability Analysis via GALDIT-GIS Method to Seawater Intrusion, South of Iraq

Abstract

One of the most significant environmental problem that needed to be identified and managed is the intrusion of salty water into the aquifers. Human actions, such as excessive irrigation pumping, as well as the rising sea level, have generated a vulnerable state for seawater intrusion into aquifers. Six effective factors have been focused on evaluating seawater intrusion of groundwater Dibdibba aquifer in Basrah, south of Iraq mainly based on the GALDIT-GIS model involving the groundwater occurrence, aquifer hydraulic conductivity, groundwater levels above sea level, distance to shoreline, impact the existing status of seawater intrusion, and thickness of the aquifer. Water samples were collected for 19 wells over the area concerned. Chemical parameters including SO₄²ˉ, Clˉ, and Total Dissolved Solids were applied for modeling in addition to measuring depth to groundwater level. The results of the GALDIT model showed that the Dibdibba aquifer revealed three levels of vulnerabilities arranged according to risks: a high level which occupied Umm Qasr area and the near distance of Khor Al-Zubair to shoreline with an area of 76.87 Km² and 82.56 Km², moderate level represented the long distance of Khor Al-Zubair to shoreline and Safwan areas about 205.21Km² and 196.61 Km², and low level represented Al-Muwailihat area with 139.65Km² and 142.61 Km² for the wet and dry season, respectively.