AN EXPERT SYSTEM TO EVALUATE ENVIRONMENTAL SENSITIVITY: A LOCAL - SCALE APPROACH TO DESERTIFICATION RISK

Under scenarios of increasing climate aridity and h uman pressure, Ecosystem Sensitivity to Desertification (ESD) is one of the most important targets for sustainable land management. This proce ss is particularly complex in the Mediterranean region since it involves multifaceted, interacting factor s that depend on endogenous conditions and exogenous pressures. Environmental indicators quantifying the ESD level at local scale should reflect the interac tion among biophysical and socioeconomic factors that are (directly or indirect) associated to soil and l and degradation. This paper illustrates a Geographi cal Information System (GIS) investigating the main fac tors determining ESD at land unit scale. This tool incorporates a Decision Support System (DSS) capable to simulate the effect of short-term environmenta l changes on the ESD (hereafter 'DSS-ESI'). The final output of the DSS-ESI is a composite index of land sensitivity to desertification (ESI) calculated sep arately for representative land cover types. The il lustrated system was supplemented by a web-based interface which estimates the overall level of land sensitivity under different climate, population, and policy sce narios. The paper illustrates the main results prod uced by the DSS-ESI in a study site application (Basilic ata, Italy) and comments about its applicability to other Mediterranean areas. Monitoring systems like the on e illustrated here may support local-scale response s to mitigate land degradation in the Mediterranean b asin.