ABSTRACT
ABSTRACT: In arid countries, where water resources are scarce, the various aspects related to water management and water uses are interlinked at the national scale. Tunisia is fairly advanced in water resource planning and management and its scarce hydraulic resources are almost entirely mobilized. The country is therefore obliged to apply new concepts, new paradigms, to optimize the use of different types of water resources. A comprehensive model for water balance of Tunisia has been developed and adjusted from data at the national scale. This model takes into account all of water resources: the withdrawal water BlueWater, the Equivalent-Water of the rainfed agriculture GreenWater, and the net contribution in Equivalent-Water of the import-export food balanceVirtual Water. The model is used in order to simulate three scenarios for the prospective horizons 2025 and 2050. The first two scenarios are based on a traditional vision of the water resource which considers only the withdrawal water management Blue Water. The third scenario considers the total water resource potential involved in food production. The simulations indicate that the improvement of food safety will depend, in the future, on the capacity to manage all the available water resources, in particular by improving the potential of rainfed agriculture.
