Towards a multi-risk assessment of Open Spaces and its users: a rapid survey form to collect and manage risk factors

The Built Environment (BE) with its users is increasingly prone to SUdden-Onset Disasters (SUODs), such as earthquakes and terrorist attacks, and SLow-Onset Disasters (SLODs), such as those related to pollutions and heatwaves. In this regard, historical centers represent vulnerable contexts due to their morphological complexity, construction peculiarities, and user-related characteristics. Therefore, risk assessment studies emphasize the importance of characterizing the BE from a holistic perspective to identify risk factors that interfere with disaster response. In particular, Open Spaces (OSs) (e.g., streets, squares) play a key role in increasing the overall BE resilience as elements that ensure the safety of BE users in emergency phases. This research is aimed at providing a quick OSs survey form to collect and manage the main risk factors according to a multi-risk approach. The form focuses on the critical users-BE interactions due to the OSs modifications during disasters and has been applied to 8 case studies in Italian historical city centers. Results show how the form can assess the OSs complexity and trace the main morphological, constructive, use-related, and context risk factors affecting the safety of OSs and their users. Promoted in the context of the Italian research project (PRIN) BE S2ECURe, the research succeeds in defining a quick methodology for risk factors collection, which can also support planners and local administrations in promoting effective mitigation strategies.