Wildfire Tribune: Are most wildfires arson?

Wildfire tribune: Society asks and our PCF Members answer

In this first article you asked us, among other questions, about the effects of climate change on forest fires, or if forest fires mostly occur because they are caused or if there are species in danger of extinction due to the fires that were last winter in Australia. Let's see what our experts have answered.

Your questions have been answered by the following PCF Members:

• MR: Martí Rosell (Forest Engineer)
• MP: Maria Pipió Adroher (Forest engineer of the Girona Provincial Council)
• FD: Ferran Dalmau Rovira (Forest Engineer)
• JM: Jordi Monge i Comas (Forest specialist technician. Preventive planning and social participation in forest fire prevention)

1.- Are the vast majority of forest fires caused?

2.- Is there an increase in the number of forest fires over the years? If so, is it due to climate change or change in the way society acts?

FD: Complex problems cannot always be explained with simple answers, and forest fires are complex. For fires to be worse, there need not be more ... it is enough that the territory through which they take place is worse ... Both climate change and the abandonment of the rural world have to do with the so-called Great Forest Fires. For providing data: 82,2% of the municipalities in Spain are rural but represent only 16,2% of the population.

JM: The number of fire "attempts" has not increased too much in recent years. What does vary is its intensity, and therefore the damage they cause. Climate change favors the fire to find drier vegetation, which burns more easily. Furthermore, as a society, for different reasons, we have stopped taking advantage of renewable forest resources. So what we no longer consume can be found and consumed by fire if a fire breaks out.

3.-I would like to know if the situation of confinement due to Covid-19 and the lack of intervention of human beings in the ecosystem are positive aspects for the prevention of forest fires. Or if, on the contrary, this lack of intervention in forestry work damages such prevention.

5.- When the fires manage to reach the urban-forest interface, the extinction work acquires an increasingly focused focus on the microscale. One of the main characteristics of the microscale is the heterogeneity that can exist in all the houses. In this context, how are the extinguishing media aware of what kind of scenarios they will have to face? Are previous studies carried out at this microscale level or is the extinction coordinated “in real time” from the control posts?

FD: 80% of the municipalities in high fire risk areas in Spain do not have specific prevention plans, so it is often necessary to work "in real time". To make them aware of what they can defend, and what they cannot, the extinguishing media are trained to be able to work with certain security, but many times it is not possible due to the lack of previous work. Prevention is the foundation on which the success of extinction rests.

6.- I would like to know if there is any application or web page that indicates the probability of fires by zones in real time and, if so, what parameters are used to assess said probability? Before going to the field / mountain it would be good to consult a reliable source that informs you on this topic.

FD: AEMET publishes information every day in http://www.aemet.es/es/eltiempo/prediccion/incendios and warn of how the situation is. Each Autonomous Community also usually publishes daily at risk level in their social profiles and some even have applications specific reports on the user's phone

7.- I would like to know the maximum distance that I can deforest around a dwelling inside forest land

MR : Depends on the legislation of your area (Country, region ...). There is no limit, as long as the corresponding cutting permit is available. If deforestation involves a change in use (from forest to agricultural, pastures are considered forest), the corresponding permit must be applied for.

FD: It depends on the autonomous community, on whether the house is in the middle of a slope, in a flat area, in a sunny or shady area,… it is advisable to act on the 30 meters that surround the house, and not always deforesting. Removing firewood stacked under a window, an awning attached to a balcony, putting shutters or choosing suitable species, is better in terms of fires, more aesthetic in terms of landscaping and better in terms of Climate Change (more shade, less temperature, more humidity ... )

JM: It is variable, it will depend on the forest regulations of each Autonomous Community. In most regulations, a security strip is specified, reducing the density of trees and scrub. These can also be complemented with measures regarding buildings, distances between tops, height of branches with respect to the ground… Although permits can always be requested beyond the fire regulations that allow us to further expand these strips. Consult specifically with forest agents in the area.

MP: The minimum distance that the perimeter strips of prevention must have around buildings located in forest land or less than 500 m from it is 25 m. However, they can be extended as long as the land on which it operates is owned by the same owner as the building to be protected or an agreement is reached with said owner. You can also expand the strip or modify its characteristics if there is a report from a forest practitioner that indicates it.

8.-Why does the fire go out with fire?

FD: Sometimes because there is no other choice =) bringing water to certain areas is impossible and using the technical fire allows the fuel (vegetation) to be consumed before the fire arrives. If you take away the food, the fire dies. There are also prescribed burns (sometimes proscribed =)) that consist of making controlled burns in winter with low temperatures, high humidity, little wind ... to generate discontinuities and that in case of fire the damage is less

JM: One of the attacks used in extinguishing a fire is the action on the fuel, with different methods, among which is its elimination. Knowledge-applied fire is a technique that allows us to reduce this fuel to directly affect the evolution of a fire. The increasing knowledge of fire extinguishing professionals by professionals increases the techniques, safety and efficiency of fire application.

9.- Why in Spain there is no unified criteria for the management of forest fire devices?

FD: The competence on forest fires rests with the governments of each Autonomous Community, for which each one has developed its prevention and extinction mechanisms. However, there are more and more meetings, seminars and conferences in which the different devices and methodologies are exposed and debated to improve coordination between teams from different backgrounds. There are organizations such as the Pau Costa Foundation that help to stimulate these positive exchange “forums”.

10.- In relation to the particles and other polluting substances that are released in a large fire. Are they well described? Are they harmful to health? Do you know how far they can go? Could they affect the health of nearby populations? If so, in what sense?

FD: The composition of smoke and particles is known. And there are "immission" models that explain where they land. They will go further or less, to some areas or others, depending on the wind, stability or atmospheric instability ... Children are especially vulnerable to environmental hazards derived from forest fires since they breathe more air than adults, are exposed to combustion by-products of wood, plastics, released chemicals and can cause problems

11.- After the images that have been seen of Australian fires, is there any estimate of the number of species at national and global level that are threatened or endangered by forest fires

FD: There's a lot. And the advance of the climate emergency worsens it. To give an example: in Spain there are more than 370.000 square kilometers at risk of serious desertification. If the desert advances, the current ecosystems are lost. The desert is another ecosystem, but the species that existed either adapt or leave or die. Great Forest Fires are a vector for the spread of desertification, hence the importance of preventing them.

If you don't see your question, don't worry about why it will appear in the next article. Every month we will publish the answers to your questions.