2022 Summer fires in the Living Lab in Nouvelle Aquitaine, France

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Summer conditions in Europe during summer 2022

The Technical report of the European Commission’s Joint Research Center points out that 47% of Europe is in warning condition due to a severe drought that caused low levels of soil moisture and vegetation stress during the summer of 2022.  Drought hazard has been increasing, especially in countries like Italy, Spain, Portugal, and, France. Regions like northern Italy and south-eastern France were already affected by drought in spring 2022. They are the ones with the most worsening conditions.

The characteristics of the Living Lab is “Landes de Gascogne” in Nouvelle-Aquitaine (FR)

One of these Living Lab is “Landes de Gascogne” in Nouvelle-Aquitaine (south-west of France). In this area of about 1 million ha, the forest surface covers 75% of the land. The forest is dominated by maritime pine stands mainly associated with oak.

The high afforestation rate leads to a strong continuity in fire fuel load across the landscape.  Most of the forest is managed as regular stands, with strong efforts at weed control to reduce fire risk and improve productivity. Since 1949, there is an extremely efficient prevention system in place with forest owners’ mandatory enrollment in municipal fire prevention associations (DFCI : défense des forêts contre les incendies). These associations are responsible for installing and maintaining a number of infrastructures such as  forest roads, fire breaks, and bridges. These infrastructures, combined with an increased firefighting capacity, led to the absence of significant fire events over the summer 2022 despite an ever-present risk. The fires that occurred in this area were mainly started by human activity, while lightning represented less than ten percent of fire ignitions in the last decade.


Landiras 1, Landiras 2 and La Teste-de-Buch fire events

The 2022 summer season has been characterized by an extremely long and dry period (August 2021 to May 2022 was the driest period since 1950 in France). Pines started to lose their needles in June,  making a deep litter. Three wildfires (Landiras 1, Landiras 2, and La Teste-de-Buch fire) started in early July when there were extremely high temperatures (around 40°C) and on an extremely dry day with air humidity below 10% for many hours. These conditions were extremely unusual for this area, even in summer. This warm and dry weather lasted for more than one week due to winds blowing from the east side. Eastern winds prevented the moisture from the ocean to reach the land, hence the formation of clouds and rain.

Landiras 1 (in blue) and Landiras 2 (in orange) fires La Teste-de-Buch

The Landiras 1 and La Teste-de-Buch fire were simultaneous events. The one in La Teste-de-Buch occurred in a very touristic and peri-urban zone with large campsites. This required the evacuation of 6.000 tourists and more than 30.000 inhabitants. Several strategies were put in place, which proved very effective to stop the fire progression and limit the burnt area to 7.000ha. Those strategies included the opening of large fire breaks[1] (in la Teste 300m*4km), tactic fires [2] on 20km, and backfires[3] on about 2km.
The Landiras 1 fire developed in a rural area dominated by forest. Many villages had to be evacuated (8.000 inhabitants in total) and it burned an area of 13.800 ha. About 1.700 firefighters and 6 aircraft were involved.

Surprisingly, on the 10th of August the fire at Landiras was reactivated (referred to as “Landiras 2”) on a 2km front with extreme heat and covered an unbelievable area of 6.000 ha in one night, requiring massive resources (1.300 firefighters and 100 fire trucks) to stop it before crossing the highway to Spain in one of the busiest week of the summer. 12.500 persons were evacuated. The total area burnt from the Landiras 2 fire was 7.400 ha.

[1] A firebreak is an area of open land in a forest that has been created to stop a fire from spreading.

[2] Tactical fire means the use of fire in the context of wildfire fighting. It consist in the ignition of a fire along a support zone with the aim of reducing the availability of fuel and thereby reducing the intensity of the fire, terminate or correct the extinction of a buffer zone so as to reduce the likelihood of recurrence or create a safety zone for the protection of persons and property.

[3] A back fire is a fire that is deliberately initiated in front of an active fire front, usually a forest fire, grass fire, or some other type of wildfire. The backfire consumes some of the combustible material and creates a fire belt that the wildfire has difficulty crossing.

Fire break opening in La Teste (300m*4km)

Unfortunately, forest fires did not stop during September. Although to a lesser extent, September remained an unusually warm month, and an additional area of 3400ha was burnt in the region of Saumos (northwest of Bordeaux). 1800 persons were evacuated and the fire lasted 3 days.


How can FIRES-RES contribute?

The wildfires that occurred in Aquitaine this summer resulted from very unusual extremely dry and hot weather that may occur more often in the future. This demonstrates that some structural changes are needed regarding land use organization in view of a proper post-fire restoration.

Some of the tasks planned by FIRE-RES aim at addressing the landscape structure and adjusting land use to limit the continuity of the fuel load taking advantage of existing infrastructures (eg., roads, railway lines, and powerlines, solar panels). This work will be possible thanks to the updated modeling tools developed jointly by INRAe and Canadian researcheers,  which are already in use in emergency services. Some of FIRE-RES tools will be also useful to improve the design of forest/urban areas interface, reinforce the importance of existing fire-break rules, and allow recommendations for urban planning and insurance schemes.