Multi-risk analysis on European cultural and natural UNESCO heritage sites

A multi-criteria risk analysis to identify and to rank the most critical UNESCO World Heritage Sites (WHSs) in Europe was implemented in the framework of the JPI-CH PROTHEGO project. The presented approach considers three natural geo-hazards (i.e. landsliding, seismic shaking and volcanic activity) for which homogenous European hazard maps are available. The methodology is based on a quantitative and reproducible heuristic assessment of risk through the development of a new UNESCO Risk Index (URI), which combines the level of hazard with a potential damage vector. The latter expresses the expected level of damage as a function of the type of heritage site (monuments, cultural routes, rock-art sites, cultural landscapes, earthworks/hominid sites, walls and natural sites), the position with respect to the ground (underground or overground) and the hazard type. The methodology was applied both to the entire WHS site and to the different properties that compose the site, with the purpose of identifying areas, inside the same site, with different level of risk. At European scale, the spatial distribution of risk reflects the fact that only three hazards were implemented in the analysis so far, with highest values in the Mediterranean area due to the importance of seismic hazard.