Toward a spatially explicit analysis of land vulnerability to degradation: a country-level approach supporting policy strategies.

Abstract

Vulnerability to land degradation in Mediterranean Europe increased substantially in the last decades because of the latent interplay of climate and land-use change, progressive soil deterioration, and rising human pressure. The present study provides a quantitative evaluation of the intrinsic change over time in the level of vulnerability to land degradation over a representative Mediterranean area (Italy) using a normative indicator, the percentage of land classified as 'critical' in total area. This indicator derives from a spatially explicit elaboration of the ESA (Environmental Sensitive Area) Index (ESAI), a standard methodology of land classification considering different levels of vulnerability to degradation at a particularly refined spatial scale (1 km2). This indicator was calculated over a relatively long time interval (1960-2010) and aggregated at the geographical scale of administrative regions in Italy, a relevant domain in the implementation of the National Action Plan (NAP) to combat desertification and the adoption of individual Regional Action Plans (RAP). A significant - but spatially heterogeneous - increase in 'critical' land was observed in Italy, leading to distinctive dynamics in northern/central regions and southern regions. Climate aridity and anthropogenic pressure leveraged the sudden vulnerability in some marginal land of Northern Italy - a region classified as unexposed to desertification risk - paralleling the levels observed in some districts of Southern Italy, an 'affected' region to desertification risk. These results suggest a re-thinking of mitigation policies proposed in the Italian NAP and a redesign of the RAPs toward place-specific adaptation measures, especially in the 'less exposed' Northern Italian region.