Integration of water contamination indicators and vulnerability indices on groundwater management in Menzel Habib area, south-eastern Tunisia

Abstract

Groundwater salinization is a major problem throughout arid and semi-arid areas due to different natural processes and anthropogenic activities and has caused irreparable environmental and economic effects. The objective of this study is to evaluate groundwater vulnerability of Menzel Habib which has been firstly assessed using multiple methods such as DRASTIC, DRASTIC pesticide, SINTACS and SI models. These indices are based on combination of intrinsic and specific characteristics of the aquifer. Almost the area presents a low to moderate vulnerability with the highest vulnerability on the western region, associated to lower deep of groundwater and evaporation processes, with consequent salinity increase. Total Dissolved solids, chloride, sodium, sulfate, calcium, and magnesium water contents were determined in a total of twenty-five groundwater samples from Menzel Habib aquifer. The accuracy of the best robust model was evaluated by the correlation between the different vulnerability indices and contamination water indicators. The main aim of this study is the development of a modified vulnerability index, DRASTIC_Sal, which includes the contribution of total dissolved solids from Menzel Habib groundwater. DRASTIC_Sal index is a simple approach for aquifer salinization vulnerability assessment, particularly for inland aquifers from arid and semi-arid regions with associated agricultural activities.