Construction of Thermal Tunnel to study behaviour of large fires

 

Porto, Apr 23, 2023 (Lusa) – The specialist who studied the fires of 2017, Domingos Xavier Viegas, warned today that, despite the occurrence of large fires being more “probable” in the Centre and North regions of Portugal, these phenomena can happen “everywhere”.

“Our experience shows that they can occur practically everywhere. In the regions of Central and Northern Portugal, where the topography is more complex and the vegetation is more prone to fires, it is more likely, but we have already seen large fires in regions where, at the outset, it was not expected”, warned the researcher from the Coimbra University.

Recognizing that the country has learned some lessons from the fires of 2017, in which 114 people died, the specialist who was part of the Independent Technical Observatory and coordinated the studies requested by the Government on those fires considers, however, that it has not been “enough”, guessing “a long way to go”.

“From a scientific point of view, studying them and understanding them is better. Then, of course, preparing the operational community to face it – above all to do it safely – and, finally, to prevent and sensitize the population to, in its occurrence, avoid panic situations and last-minute escape attempts, as happened in Pedrógão Grande that caused loss of life”, he said

Four months later, on October 15, already after the so-called critical fire season, the worst day of the year in terms of the number of fires was recorded, with more than 500, with the flames reaching 27 municipalities in the Centre region in particular and causing 51 deaths. . In this case, more than a third of the fatal victims died at home, with many of them having been caught by fire while they were sleeping.

In an effort to better understand phenomena such as what happened in Pedrógão Grande, the Centre for Studies on Forest Fires (CEIF) at the University of Coimbra (UC) is building a thermal tunnel, whose assembly, said its coordinator, Xavier Viegas, is in advanced stage.

“We hope to run tests later this month. We are very hopeful that it will be equipment that will allow the study of processes [namely large fires] that are still poorly understood by the scientific community and also by the operational community exactly about the role of the vertical stability of the atmosphere in the propagation of fire”, he explained.

It is the conviction of the UC researcher that the importance given to the role played by the atmosphere is “exaggerated”, insofar as – mainly in large fires – there is sometimes the “development of a very strong convection – produced by the fire – and that, eventually, if there is an unstable atmosphere, it can potentiate it”.

With this equipment, the forest fire specialist hopes not only to understand fundamental aspects of fire behaviour, but also to contribute to the training of firefighters and civil protection agents to fight major fires, such as the one that broke out last year in Parque Natural from Serra da Estrela and spread between the 5th and the 23rd of August.

Classified as the 6th largest to occur in Portugal, since there are records, the fire reached 22 parishes, six municipalities, having consumed a total of 22 hectares in the Natural Park of Serra da Estrela.

In that fire, which “fortunately” did not have the proportions observed in Pedrógão, as in others that occurred last year, explains Xavier Viegas, it was possible to identify “situations of fronts meeting that produced a very large acceleration”, as is an example, from the fire in July 2022, in Murça, where a man and a woman, aged around 70, died when they tried to flee the fire by car.

“The accident was preceded by a meeting of two fire fronts which led to the fire spreading very quickly. In Serra da Estrela the same thing”, he indicated, stressing that “interaction with the atmosphere does not always play a fundamental role”, as happened in Pedrógão, where the thunderstorm influenced the behaviour of the fire.