Preliminary risk assessment ai Ustica based on indicators of natural and human processes

Geomorphological phenomena have significant repercussions on environmental evolution, triggering changes in natural processes that might have a severe socio-economic impact. To date, vulnerability estimations have been primarily based on natural processes, and secondarily by combining the exposure resulting from socio- economic variables, which can assist in identifying areas under risk. The present investigation proposes a methodology to examine the risk from natural hazards by introducing social indicators as exposure factors. The methodology is based on a combination of socio-economic and natural indicators. In this work the different indicators form indices that are used to make holistic risk estimation for both inland areas and coastal areas. This approach includes four sub-indices that contribute to the overall risk estimation. The sub-indices refer to the geomorphological characteristics, together with natural forcing, coastal erosion for the estimation of the vulnerability and socio-economic indicators for the estimation of exposure. All variables are ranked on a 1-5 scale, with rank 5 indicating the highest, and are estimated in a GIS model. The main difficulty in making theseestimations lies in assessing and ranking the socio-economic indicators, and especially cultural heritage sites since their importance cannot be measured. The risk is estimated by using the vulnerability of the area and the socio-economic sub-index that function as the exposure variable in the estimations. This work is an initial approach as part of the Brains2Islands project funded by Fondazione con il Sud and aims to develop a best practice guide for cultural heritage resilience to natural hazards, that will be tested and validated through field studies, using as a case study the island of Ustica, an area of high cultural and economic value, with ancient monuments