Hydro climatic ranking of small Mediterranean islands

Islands are specific environments whose natural features form the basis of social and economic development. It is particularly distinct on small islands. In hydrological terms, these are islands with surface areas between 100 and 1000 km2. There are 40 small islands in the Mediterranean Basin. Most of these have very limited water resources, due to their geological structure and precipitation regime. This paper outlines the basic geographical and climatic features of small Mediterranean islands. It also suggests a ranking of islands with respect to an annual precipitation, precipitation surplus and hydrological size. In addition to an island's precipitation regime and geology, size and shape also influence its water potential. That effect, islands with a more elongated shape have more expressed water scarcity. Adriatic and Ionian islands share the most favorable hydro climatic conditions in the Mediterranean area, Tunisian islands and the Cyclades have the least favorable ones.