Geo-environmental risk analysis for a sustainable local territorial management.

The study focuses on the assessment of the potential damage to the elements at geoenvironmental risk in Ricasoli village (Municipality of Montevarchi in Arezzo Province, Tuscany Region, Italy), affected by landslides, and Stromboli island (Municipality of Lipari in Messina Province, Sicilian Region, Italy), affected by landslides, volcanic phenomena, tsunamis and earthquakes. The proposed methodological framework is the result of the intersection of two different approaches to the risk analysis: the geo-scientist approach and the approach developed by the Territorialist School of urban and regional planning and design. In order to implement strategies for prevention, reduction and mitigation of geo-environmental risks, the vulnerability and exposure were separately examined, even so maintaining a general overview. At the same time the hazard was necessarily considered a self-reproducing rule because it represents the keyelement for a sustainable and resilient Territorial Government wherever a natural event may occur, regardless of its variation in the probability of occurrence over time (e.g. floods or landslides are particularly dependent on climate changes). The preliminary analyses were mainly crucial to define the territorial heritage, which considerably influenced the exposure value and the potential damage to the elements at risk (i.e. buildings, infrastructures, land uses). Moreover, ex novo building-sheets and infrastructure-sheets were created in order to collect the proper data on the compositional characteristics of real estates, with the purpose to assess their physical vulnerability at intermediate scales (i.e. 1:2.000, 1:5.000, 1:10.000) as accurately as possible. Finally, semi-structured interviews and surveys to inhabitants and tourists were useful to make some preliminary consideration on risk perception and calibrate the future interventions. The main results of the study show the strong correlation between the high or moderate-high heritage value of the elements at risk and their high potential damage: the intrinsic value, which is related to the historical-cultural, social, identity and landscape values, considerably increased the initial market value (buildings), construction coast (infrastructures) and agricultural average value (land uses) of real estates, according different scenarios in both case studies.