Flood Risk Assessment of Cultural Heritage: A Comparative Study in Two European Countries

Floods are a very threatening natural hazards for cultural heritage, thus risk assessment is a crucial step to develop effective mitigation strategies. This study presents a comparative flood risk assessment for cultural heritage over Portugal and Po River Basin in Italy with the aim to evaluate the impact of using different resolution hazard maps in the risk estimation. Furthermore, it is proposed an improvement of the framework developed by Figueireido et al. (2019) by trying to find a common procedure to estimate flood risk on cultural heritage on a large-scale application for two different countries. Cultural heritage database and hazard maps were collected in a GIS environment, thus spatial analyses were performed by applying GIS techniques to develop hazard and exposure maps with a multiple comparison. Cultural heritage vulnerability is evaluated by applying a simple depth-damage function throughout the calculation of a vulnerability index (HFI index), which requires the extrapolation of water depth values associated to each asset. The results suggest that global hazard maps are not able to correctly represent neither the inundated area nor the exposed cultural heritage elements. Continental hazard maps reach a better agreement with the official hazard maps, but they are very sensitive on the area considered, given the limitation of the original hydraulic model. This work could be used as a basis for decision-makers to set the priority among cultural heritage sites, that needs further investigation.