The role of urban configuration during disasters. A scenario-based methodology for the post-earthquake emergency management of Italian historic centres

摘要

Earthquakes have high impact in Italian historic centres, and the complex disaster chain still causes considerable casualties and damage to the built environment. In these contexts, the seismic risk assessment is a challenging task. Therefore, the emergency management offers a mitigation strategy to reduce or avoid the potential losses associated to a seismic event. Despite the efforts in developing procedures to improve the emergency planning, the peculiarities of historic centres have been so far neglected. This paper assumes that the urban configuration and morphology of historic settlements have a key role in the definition of urban safety and resilience. By adopting an interdisciplinary approach, the research aims at implementing the spatio-configurational aspects into the post-seismic emergency management of Italian historic centres. The application of a scenario-based method offers a predictive approach to emergencies which embeds the uncertainties of the effects of earthquakes. The methodology is based on the development of road network's scenarios and their analysis by means of space syntax techniques. It starts from the evaluation of vulnerabilities and the mapping of the emergency system. Then, it analyses the road network in order to identify the more attractive routes of the configuration. Finally, different simulations of inaccessibility scenarios are proposed and expressed in terms of interferences with the road network. The methodology has been applied to the historic centre of Lucignano, in the Central Italy, demonstrating the effectiveness of spatial analyses in addressing the route-finding decision making during the evacuation process and in selecting the location of emergency areas.