Multi-Hazard and Multi-vulnerability Analysis in Historical Urban Areas: Challenges and Opportunities

Natural hazards increasingly threaten urban areas, and single-risk analyses performed within different methodological frameworks are often not comparable with each other and pose some difficulties for decision-makers. This work highlights the challenges and opportunities of multi-hazard and multi-vulnerability assessment in historical urban areas with a multi-disciplinary approach. Two hazards, i.e., seismic and flood, are included in a multi-risk workflow based on common exposure, vulnerability, and risk metrics. The city center of Florence (Italy) is selected to demonstrate the methodology. The application suggests that estimating direct physical damages for earthquakes and floods requires a different characterisation of exposure and vulnerability parameters. The results show significant differences in the spatial distribution of multi-risk, mostly depending on the evolution of the constructive typologies from the Middle Ages to the XX century and the anthropic alteration of terrain morphology.