Italy is located in one of the most earthquake prone areas in Europe with one of the richest cultural legacy in the world. In the last decades, a series of seismic events caused considerable casualties and damage to the built environment in Italy, highlighting the need of undertaking proactive measures to limit the impact of any potential earthquake on the urban system. The most vulnerable areas are historical city centres whose complex current morphology is the result of a centuries-old processes of aggregation, space saturation and adaptation to the territory. Besides, the great number of historical buildings contributes to the built-up of high exposure to hazard. Since 2009, after the dramatic L’Aquila earthquake, the Civil Protection Department introduced and consolidated a disaster relief system based on top-down policies to deepen knowledge about site-specific hazard and address preventive planning, providing funding and assistance to local urban planners. Although the programme is still in progress, three points still emerge in the experience. First, the actions have been partially implemented with important shortcomings in the nationwide development of studies and plans. Secondly, the preventive planning has involved so far only strategic buildings while no initiative has been undertaken to improve the capacity of the urban system to cope with the consequences of the event. Third, emergency management plans do not encompass historical centres, thus neglecting their peculiarities and complexities.This paper introduces an interdisciplinary approach to implement the post-seismic emergency management into Italian historical centres and consequently address their preventive planning. The procedure combines space syntax techniques and vulnerability analyses to evaluate their resilience to earthquakes. The first step is the survey of the present-day configuration, with its historical assets, aggregates, critical infrastructures, urban functions and strategic activities. Then, the vulnerability analysis of the urban fabric supports the prediction of post-seismic damage scenarios, detecting possible debris that can obstruct routes causing their loss of accessibility. Finally, assuming that human behaviours are influenced by the townscape, the syntax analysis offers a measure of the resilience of the grid and allows selecting the “sensitive paths”, namely the more attractive routes of the configuration in terms of movement. This exploratory study considers different historical settlements in Tuscany, taking into account the influence of the spatial elements on urban resilience. For each case study five scenarios have been investigated, providing the routes that inhabitants or rescue teams would most likely follow during an emergency. The comparison between the spatial properties offers a measure of the influence of the configuration on the emergency management and is the starting point for the development of mitigation strategies. On this basis, it will be possible to rank priority intervention into a preventive plan in order to ensure free escape routes and clear access for the emergency services during the post-seismic phase.

URBAN GRID AND SEISMIC PREVENTION - A CONFIGURATIONAL APPROACH TO THE EMERGENCY MANAGEMENT OF ITALIAN HISTORIC CENTRES

Valerio Cutini;Anna De Falco;Francesca Giuliani
2019-01-01

Abstract

Italy is located in one of the most earthquake prone areas in Europe with one of the richest cultural legacy in the world. In the last decades, a series of seismic events caused considerable casualties and damage to the built environment in Italy, highlighting the need of undertaking proactive measures to limit the impact of any potential earthquake on the urban system. The most vulnerable areas are historical city centres whose complex current morphology is the result of a centuries-old processes of aggregation, space saturation and adaptation to the territory. Besides, the great number of historical buildings contributes to the built-up of high exposure to hazard. Since 2009, after the dramatic L’Aquila earthquake, the Civil Protection Department introduced and consolidated a disaster relief system based on top-down policies to deepen knowledge about site-specific hazard and address preventive planning, providing funding and assistance to local urban planners. Although the programme is still in progress, three points still emerge in the experience. First, the actions have been partially implemented with important shortcomings in the nationwide development of studies and plans. Secondly, the preventive planning has involved so far only strategic buildings while no initiative has been undertaken to improve the capacity of the urban system to cope with the consequences of the event. Third, emergency management plans do not encompass historical centres, thus neglecting their peculiarities and complexities.This paper introduces an interdisciplinary approach to implement the post-seismic emergency management into Italian historical centres and consequently address their preventive planning. The procedure combines space syntax techniques and vulnerability analyses to evaluate their resilience to earthquakes. The first step is the survey of the present-day configuration, with its historical assets, aggregates, critical infrastructures, urban functions and strategic activities. Then, the vulnerability analysis of the urban fabric supports the prediction of post-seismic damage scenarios, detecting possible debris that can obstruct routes causing their loss of accessibility. Finally, assuming that human behaviours are influenced by the townscape, the syntax analysis offers a measure of the resilience of the grid and allows selecting the “sensitive paths”, namely the more attractive routes of the configuration in terms of movement. This exploratory study considers different historical settlements in Tuscany, taking into account the influence of the spatial elements on urban resilience. For each case study five scenarios have been investigated, providing the routes that inhabitants or rescue teams would most likely follow during an emergency. The comparison between the spatial properties offers a measure of the influence of the configuration on the emergency management and is the starting point for the development of mitigation strategies. On this basis, it will be possible to rank priority intervention into a preventive plan in order to ensure free escape routes and clear access for the emergency services during the post-seismic phase.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/998578
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