The forest fire of Las Tablas, which in February of 2024 took the lives of at least 135 people and destroyed thousands of houses in the cities of Viña del Mar and Quilpué, continues to be the subject of academic analysis in order to understand its structural causes and prevent future tragedies. In this context, a recent international study published in the scientific Journal of Pyrogeography analyzed the dynamics that transformed this event into the second deadliest urban conflagration at the global level in the modern era, since Black Saturday fires in Australia in 2009.
We use the term urban conflagration to refer to a fire of great magnitude that spreads rapidly and destroys multiple buildings, blocks or entire areas of a city. Unlike a common structural fire, this phenomenon completely exceeds the response capacity of local departments due to its magnitude and speed of movement.
The study was developed by the Master’s in Geography graduate from the Pontificia Universidad Católica de Valparaíso (PUCV), Manuela Penas, together with professors Andrés Moreira, Rosa Zamora and Luis Álvarez, from the Institute of Geography at the PUCV; and researchers from the University of Concepción and the Universidad Merced in California. This team of national and international experts recreated the advance of the fire minute-by-minute and identified the main biophysical and social factors that resulted in this disaster.
The perfect storm: Climate change and extreme conditions
The study analyzed how the prolonged mega-draught in the central area of Chile since 2010, in addition to extreme heat waves and dry winds, created the ideal scenario for the fire to behave without control. During the day on February 2, 2024, the temperature exceeded the historical average by 30% and the relative humidity fell under 30%, which results in what is known in Chile as the “30-30-30” scenario, favorable for forest fires.
“The climate crisis is causing the days with favorable conditions for the occurrence of events to increase within the fire season and these, at the same time, are becoming longer. Days with extreme heat and low atmospheric humidity associated with heat waves are more frequent, which in addition to predominant wind, creates ideal conditions for the development of events that can have disastrous results”, Manuela Penas noted.
Social Vulnerability and planning deficit
In addition to the climate variable, a determining factor appeared: the vulnerability of the territory. The study addressed how non-regulated urban expansion, the proliferation of informal settlements or hillside camps and the building with light materials complicated the evacuation and rescue process, making this event a deadly trap.
To this respect, the PUCV scholar Andrés Moreira explained that in the greater Valparaíso area, planning usually only considers urban areas, which disregards the great extensions of land in the urban-forest transition areas. “Planning arrives late, but it is also leaving areas that are key in regard to the dissemination/control of fires. The urban/forest interface area is where vegetation exists, especially exotic, and it mixes with buildings. Those areas where the density of houses is high and materials are highly flammable become extremely vulnerable to fire occurrence, which is also added to the change in local micro-climate conditions that produce the exotic species such as the pine and eucalyptus, which totally modify the availability of humidity on the ground and surface, and also present physiognomic evolutive characteristics que tend to combustion”, he added.
Along the same line, Manuela Penas explained that there is another category of fuel that is also relevant and that must be managed given its importance for the spreading of the fire: seasonal vegetation as a result of winter rain.
“To determine safe evacuation routes is the responsibility of municipalities especially in these areas with high density, and that continue to expand, where they must be thought of and implemented according to the local realities that are, above all, extremely dynamic. Planning should also consider everything that has to do with the irregular disposing of waste”, Penas noted.
Challenges for the Pyrocene
Research concluded that Chile is immersed in the Pyrocene or the Age of fire, a new geological era that is characterized by the proliferation of massive fires fed by human activity and global warming.
In this scenario, Moreira and Penas agree that being a part of the paradigm change is to acknowledge that the climate crisis is a reality and that this requires the development of research that updates the understanding of the phenomenon “and incorporates the different sectors of the society, that are involved in the different phases associated to fires, so that actions are developed from the field”.
Finally, the authors emphasized that it is urgent to adapt the mitigation policies, strengthen the early alert systems and update building regulations in areas where the city meets the vegetation.
“One of the lessons we can take from the 2024 mega fire is that the conditions that foster the occurrence of these events are and will be more frequent, so there is an important percentage that has to do with the threat that we are not able to control and cannot have influence. It is fundamental to point to those risk components so that we can have some influence and reduce the negative impact, such as the control of available flammable material, fire control mechanisms (water availability, firewall networks, accessibility for organisms), evacuation routes, and especially in our region, to move forward in definitive housing solutions and the reduction of squatters and camps”, the PUCV Institute of Geography scholar, and co-author of the work, Luis Álvarez, added.
To access the article, please visit: https://www.sciencedirect.com/science/article/pii/S3051067826000195
By Erika Schubert
Strategic Communications Deparment
