National Atlas of Areas at Risk of Desertification — Impact Index: thin soils on strong slopes v2.0

The Ministry of the Environment and the Protection of the Territory has financed the Experimental Institute for the Study and Defense of the Soil for the Predisposition of National Atlas of areas at risk of desertification at the recognition scale (reference scale 1:100,000-1,250,000). The MATTM considers this Atlas a preparatory tool for the correct implementation of the National Plan for the Fight against Drought and Desertification, adopted by the Italian State in implementation of the United Nations Convention for the Fight against Drought and Desertification. The aforementioned act provides for the participation of the National Institute of Agricultural Economics in its specific areas of competence. The study area includes Abruzzo, Basilicata, Calabria, Campania, Lazio, Marche, Molise Puglia, Sardinia, Sicily, Tuscany, Umbria. The index of impact thin soils on steep slopes identifies areas where soils are vulnerable to water derosion processes. Areas with a slope greater than 15 % and without pedological information are classified as a lack of data. All other areas are classified as non-risk. The information layer was obtained by overlapping the two status indicators: thin soils and strong slopes. Thin soil status indicator: the thickness is a characteristic of the soil on which the derosion processes act directly, that is, determines the potential evolution towards a state of functional sterility. Soils considered potentially vulnerable are those with a rootable depth of less than 50 cm. A territorial component has been considered potentially vulnerable when at least 40 % of the soils describing it are vulnerable. Strong gradient status indicator: slope is an important factor for the triggering and dynamics of water derosion processes. Gradients greater than 15 % were considered to be strong.