Modelling Resilience to Floods in Art Cities: A Historical Perspective

Art cities are characterized by peculiar exposure and vulnerability aspects which are rarely addressed in flood risk studies. This works investigates art cities in terms of exposure and resilience by considering the effects of cultural heritage. Flood hazard considers a “what-if” scenario comparison based on an historical event as it occurred in the past and as it would occur today and in future with countermeasures in place. The analysis is carried out in the city of Florence (Italy), a UNESCO World heritage site, affected by the last flood in 1966. The results show that countermeasures have slightly reduced inundation extent (−7%) and depths. Exposure of buildings has increased (+17%), but the exposed residential population has decreased (−38%) due to gentrification. On the other side, the fluctuating population exposure has dramatically increased (+1511%). Finally, despite the limited flood hazard reduction, resilience has increased, with a reduction of post-event recovery time (−21%). In future, completed mitigations works will reduce substantially flood hazard and exposure of residents and tourists. It appears that cultural heritage plays a twofold and contrasting role. On the one hand, it attracts a fluctuating population, which increases exposure, and, on the other, it fosters the recovery.