Abstract

Among the recently funded INCO projects several address the question of desertification of the Mediterranean basin. The approach followed in CAMELEO has been to document land surface changes on the long term and to relate them to the degradation patterns observed on the ground. Results of this study on the Tunisian test site evidence a strong variability of vegetation cover and even of soil surface composition, with important sand movements linked to dry periods. However field experiment have also shown that sand sheets at the surface increase the water infiltration and overall efficiency of the rain. Other studies have focused on determining the water fluxes of typical ecosystems, mainly with field measures. Aiming at merging the two approaches, an innovative project is currently undertaken on a test site of Morcocco to determine, with ground measurements of ETR, satellite-data and SVAT models, the impact of land surface changes on the water budget, and the water use efficiency in natural and cultivated systems. Those themes are of interest to several research teams from Mediterranean area and could be developped with them into a proposal of regional dimension, developping refined tools for the global management of water for agriculture in dry regions.