Groundwater management based on GIS techniques, chemical indicators and vulnerability to seawater intrusion modelling: application to the Mahdia–Ksour Essaf aquifer, Tunisia

In arid and semi-arid countries worldwide, conflicts between human development activities and conservation of groundwater resources are widespread and attract many public debates. This research aims to propose groundwater management alternatives for a coastal aquifer by studying its vulnerability and in particularly the risk of seawater intrusion. An additional objective is to propose some agricultural policies aimed to conserve groundwater resources in Mahdia and Ksour Essaf. Intensive groundwater mining, for irrigation and for water drinking, has caused an overexploitation of the water resources. In addition, the degradation of water quality, caused by septic tanks and intensive agricultural activities, has given rise to notable crucial state of the groundwater resources. With the aim of tackling the groundwater degradation problem, integration into a common platform of vulnerability assessment, seawater intrusion modelling and hydrochemical analysis is proposed. This platform can considerably reflect the water resources state in order to propose some solutions reducing the contamination of the Mahdia–Ksour Essaf aquifer. The groundwater management alternatives, proposed in this study, were prepared within a geographical information system.