The purpose of this paper is to assess the risk of post-earthquake fire (PEF) in the historic city centre of Aveiro, Portugal, by integrating seismic vulnerability analysis, fire risk assessment and GIS-based spatial modelling. Through building surveys and scenario-based analysis, the study identifies ignition risks, fire spread potential and road blockage hazards following a seismic event. It further evaluates the impact of mitigation strategies, such as automatic gas shut-off valves, to enhance urban resilience. The findings aim to support emergency planning and inform public policies for disaster risk reduction in historic urban areas.
The study combines field surveys, photographic documentation and GIS mapping to assess PEF risk in Aveiro's historic centre. Seismic vulnerability was evaluated using index-based methods for masonry and reinforced concrete buildings. Fire risk was quantified using a modified ARICA fire risk index method, while PEF scenarios were developed by correlating damage levels with ignition risks. Fire spread was modelled using an elliptical propagation model considering wind and urban density. Road blockage risk was assessed based on building collapse potential. Mitigation measures, including automatic gas shut-off valves, were simulated to evaluate their impact on fire ignition and spread.
The study found that 51% of buildings in Aveiro's historic centre face moderate to very high PEF risk under EMS-98 intensity VIII, with masonry structures being significantly more vulnerable than reinforced concrete ones. Fire spread analysis showed rapid escalation, affecting 2% of buildings within 15 min and 19% within 30 min. Additionally, 23% of roads were classified as high risk for blockage, potentially hindering emergency response. Implementation of automatic gas shut-off valves reduced ignition risk in some buildings but had limited overall impact due to broad risk classification intervals. Key vulnerable zones were identified for targeted mitigation and planning.
This study presents a novel, integrated approach to PEF risk assessment at the urban scale, combining seismic vulnerability, fire risk, fire spread and road blockage analyses within a GIS framework. Applied to Aveiro's historic centre, it uniquely incorporates real building data and explores the impact of mitigation strategies such as automatic gas shut-off valves. The methodology's adaptability to other European historic urban areas enhances its relevance. By identifying high-risk zones and infrastructure weaknesses, the study provides valuable insights for urban planners, policymakers and emergency services aiming to improve resilience and reduce cascading disaster risks in historic city centres.
