Multi-sensor approach for analysis of extreme weather events affecting areas of cultural interest

In recent years, interest in the study of natural disasters has grown considerably, linked both to the increase in the number of such events and to the worsening of their impact on the territory. The conservation strategies of cultural heritage (whether it is movable or immovable), in response to damage resulting from the natural phenomena of aging and decay but also from the occurrence of disasters, inevitably require a methodological approach aimed at planned conservation and preparedness for the risk event of the cultural site. In this sense, the Mediterranean basin which is a unique environment for the occurrence of atmospheric phenomena, results to be a relevant example, considering that Italy currently has the largest number of sites inscribed on the World Heritage List. We examined with this aim some case studies in Italy. We have employed different meteorological data (Satellite-based observations, ERA5 model, NWP models, GNSS, Lightning detection network, Radar) to characterize events related to some case studies of potential interest. The meteorological events investigated, which caused flooding and damage in the Italian study areas, showed how the sites responded in different ways to the stresses. The architectural peculiarities, the reciprocal relationship between buildings and environment, typical of spontaneous architecture in the Mediterranean basin, and the perception of heritage by inhabitants strongly condition protection policies. In this context, the properties of buildings need to respond to three fundamental aspects: climate, building materials and the morphology of the territory. These distinctive properties have therefore contributed to sites resilience, as explored in more detail in the different works performed (UNESCO archeological site of Villa Romana del Casale, in Piazza Armerina (Sicily), UNESCO site of Sassi di Matera, Alberobello UNESCO site, Como UNESCO Creative City and Trabocchi Coast (Abruzzo) UNESCO intangible cultural heritage candidates). Results have shown the great potential of the multi-sensors approach to describe in the most complete and detailed way the intense meteorological events and to show the agreement between the products involved in the studies in order to evaluate the joint use of different platforms. Future multi-instrumental applications and potential use of some products (e.g., satellite-based) for the analysis of events of interest in areas not covered by operative tools is an issue that emerged. In particular, in all presented case studies, we started from a long-term and large-scale analysis concerning the climatology of the area, to a short-term and more local scale where we described the most acute phases of the events. Different responses to stresses have to indicate the most proper approach to face up the risks and plan the actions to preserve the cultural heritage (e.g. risk management plan, mandatory for each UNESCO site since 2019).