Scenarios of evolution of water consumption and groundwater management in the Gabes Jeffara – Tunisia

International audienceAbstract-The oases of Gabes, in the southeast of Tunisia, constitute an unique example of coastal ecosystem. The development of agricultural activity in recent decades, in a semi-arid climate subject to recurring droughts, has led to a very strong demand on groundwater ressources causing the drying of the springs supplying these oases and the lowering of the groundwater levels, with consequent salt intrusions and degradation of oases ecosystems. A hydrodynamic model has been developed for better management of the aquifer. The results of the simulations without management measures highlight the critical situation of groundwater resources related to a considerable increase in groundwater withdrawals since 1970. Different scenarios have been tested with the model, based on the use of alternative resources, on an improvement of irrigation techniques and on a reinforcement of groundwater recharge