Towards a networked open space for seismic resilience: a case study of Sulmona, a historic city in Italy

Sulmona is a fragile territory, given its exposure to frequent seismic attacks. With the densest fabric, its historic centre is the most vulnerable zone, compared to its new districts with dispersed fabric—with more open space (streets, squares, and parks) in preparedness for emergency evacuation and shelter. In the historic centre, more interconnected open space is required to ensure the safe gathering, emergency evacuation, and rescuing work. However, a contradiction exists between conserving the historic fabric and inserting more safe open space or/and modifying the existing open space for seismic resilience. Under this condition, our research tries to establish a networked open space through minimized interventions with maximum effects to raise the historic centre’s preparedness for response to earthquakes. Two stages are taken, combing space syntax and the cartographic study. First, a space syntax analysis of the existing road network is performed. It helps to identify the priority streets—which have higher spatial integration and whose suitability should be primarily achieved—for emergency evacuation. It is noteworthy that the configuration of these priority streets differs from that in the Emergency Plan by the municipality; possibilities to enhance the Emergency Plan exist. Meanwhile, it assists in locating the two most problematic areas within the historic centre, where inadequate connection to evacuation routes, insufficient safe open space, and fragmented and inaccessible open space are crucial issues to be solved. Secondly, a cartographic study of historical maps validates our choices of strategic locations for further interventions. Some certain boundary-modification and demolition is suggested to improve the circulation, insert more safe open space, and integrate the enclosed open space. The two stages allow us to plan a networked open space of the historic centre to strengthen its preparedness for earthquake response. And the approach is meant to be referential and adaptable to other similar cases in earthquakeprone territories.