Study reveals that it is urgent to adopt new constructive solutions to reduce the impacts of fires

It is urgent to change the way of construction and rehabilitation of buildings and infrastructures in the critical areas of the urban-forest interface (IUF), revealing the first results of a study by the University of Coimbra (UC) focused on promoting a sustainable, resistant and sustainable built environment. resilient to mitigate the direct and indirect economic, social and human impacts of forest fires.

Called INTERFACESEGURA, the project has funding of 299 thousand euros, attributed to the Foundation for Science and Technology (FCT), and adopts a holistic approach to the problem of fires at the urban-forest interface, bringing together several research groups from the UC (Engineering, Geography, Economics, and Law).

The main objective is «to respond directly to the serious problems that have arisen in recent decades due to lack of planning and land use planning, with excessive urban pressure on forested areas, with oversized urban perimeters devoid of public programming, the abandonment of rural spaces and primary activities that promoted the continuity of the fuel (absence of compartmentalization) and the rapid worsening of climate change», says Hélder Craveiro, project coordinator and researcher at the Civil Engineering Department of the Faculty of Science and Technology of the University of Coimbra (FCTUC).

To this end, this investigation has a very strong experimental component. Multiple real fire field trials have been carried out, in collaboration with the National School of Firefighters, benefiting from controlled fire training practices to the instrument and monitor fire behavior and assess its impact on buildings.

Com base na informação recolhida nos ensaios de campo e em ferramentas computacionais de simulação para avaliar o comportamento do fogo na macroescala (ao nível do concelho) e microescala (ao nível do edifício), já foi possível identificar, através de um caso de estudo, no concelho de Coimbra, «as zonas mais vulneráveis a incêndios na interface urbano-florestal. Esta abordagem permite simular o desenvolvimento e propagação de incêndios e avaliar com elevado nível de detalhe o impacto de cenários extremos, como os que estamos a viver, no ambiente construído, avaliando as vulnerabilidades de edifícios e infraestruturas», relata o investigador da FCTUC.

Os primeiros resultados do projeto revelam que a ocorrência de incêndios florestais junto de zonas urbanas «obriga ao desenvolvimento de novas soluções construtivas resistentes ao fogo em zonas urbanas de risco de exposição agravado, com a implementação de normas de construção para a interface urbano-florestal recorrendo a análises baseadas no desempenho, mitigando as vulnerabilidades dos edifícios a eventos extremos. Além disso, é fundamental caraterizar a envolvente dos perímetros urbanos, identificando a sua suscetibilidade a incêndios florestais, para implementação de medidas mitigadoras

Based on the information collected in field trials and on computer simulation tools to evaluate fire behavior at the macroscale (at the county level) and microscale (at the building level), it has already been possible to identify, through a case study, in the municipality of Coimbra, «the areas most vulnerable to fire at the urban-forest interface. This approach allows simulating the development and propagation of fires and evaluating in high detail the impact of extreme scenarios, such as the ones we are experiencing, on the built environment, assessing the vulnerabilities of buildings and infrastructures», reports the FCTUC researcher.

The first results of the project reveal that the occurrence of forest fires near urban areas «forces the development of new fire-resistant constructive solutions in urban areas with increased risk of exposure, with the implementation of construction standards for the urban-forest interface using performance-based analytics, mitigating building vulnerabilities to extreme events. In addition, it is essential to characterize the surroundings of urban perimeters, identifying their susceptibility to forest fires, in order to implement mitigating measures».

The team also identified which materials used in construction are more vulnerable to fire, which, according to Hélder Craveiro, «unfortunately, there is a proliferation in our country, for example, materials with an inappropriate fire behavior for their use in interface areas with risk compounded (eg sandwich panel with polyurethane core)».

In view of climate change, the study coordinator emphasizes that the «frequency and severity of fires will tend to increase, leading to the extreme need to implement measures and structural reforms in terms of the built environment and the forest in the urban-forest interface areas, mitigating direct and indirect impacts on communities. This approach makes it possible in the short/medium term to reduce risks for communities and makes possible a solid and effective forest reform (landscape reform, partitioning, and forest recovery), which will naturally take years to implement».

The study also highlights the need for «the more effective and intensive use of controlled fire to control the fuel load, as well as the development of methodologies to estimate socio-economic impacts, in the short term, for a scenario of reduction in final demand, aimed at the Portuguese economy. The paper pulp and derivatives industry was analyzed, and the results demonstrated the relevance of eucalyptus in this industry, despite the general apprehension surrounding its intensive exploitation in areas susceptible to forest fires», adds Hélder Craveiro.

Upon completion of the project, scheduled for the end of this year, the researchers involved intend to prepare and send to the Government and municipalities a document with recommendations for the implementation of policies, both from the point of view of the built environment and forest management in the vicinity of areas urban areas and in terms of resilience for communities.

Videos about some of the tests performed are available: here.