"Locally Relatively High": Expert Comments on Forest Fire Danger

The reason for this is a long warm weather period since the end of May. "It is still very early in the year, when everything should actually be much wetter," said the expert. Heavy downpours in between can do little to change the situation.

In some places, "stronger storms and thunderstorms have brought down more rain than one could wish for" in the past week, he said. But this only changed the situation for a few days. "If a heatwave and drought follow, the situation looks completely different again," said Kraxner. In addition, for example, it has not rained in Carinthia for several weeks. The forests there are therefore very dry.

On the positive side this year, it was relatively cool in April and May. "As a result, the soils were able to retain more moisture, and this has had an effect until now, early July," said the expert: "In Austria, we are therefore much better off than in Germany, where there has been an extreme drought for much longer." There, the risk of forest fires is "really extreme."

"Whether a forest fire breaks out or not depends on various factors"

"Whether a forest fire breaks out or not depends on various factors," explained Kraxner. For example, on the moisture of the air and the wood, but also on the composition of tree species, the density of the forest, and whether it is "healthy": A vital tree can draw a lot of water from deeper soil layers and partially release it into the air when it absorbs carbon dioxide from the air. This increases the moisture in the forest. This also happens through an intact, dense canopy that prevents excessive drying out.

In densely populated areas, it is very often "unwitting negligence" that leads to forest fires, said Kraxner. This includes activities such as smoking cigarettes or illegal barbecuing, for example, on riverbanks. According to the expert, the danger posed by glass bottles and shards, which can act as a magnifying glass and ignite dry leaves, is overestimated.

Open fires in the forest and embers from barbecuing are clearly more dangerous. "In France, a forest fire was recently caused by a still-cooling barbecue that was being transported on the back of a pickup truck," reported Kraxner: "The wind from driving spread the embers along the route."

A fire in the spring in the Rax area in Lower Austria was also caused by a car in the forest. It was there with permission for forestry work when a vehicle part on the underside overheated and ignited. "Although it was not a spectacularly large fire, especially along the ground, it meant an insane amount of work for all the fire departments in the area to extinguish it," recalled Kraxner: "They were on duty day and night, and helicopters also had to be deployed."

But torn high-voltage lines are also not so rarely the cause of a fire. In less densely populated areas, most forest fires, on the other hand, have natural causes such as lightning strikes.

Slope Inclination Plays a Role in Spread

How quickly a fire spreads in the forest strongly depends on the slope inclination, explained the expert: On flat terrain, it usually spreads less quickly than on a steep slope. There, the flames ignite the next tree much faster, and the thermals often carry them quickly upwards. When burning tree parts tumble down the slope, it can suddenly bring the flames downhill. "This is also extremely dangerous for the fire brigades, which of course have to fight the fire from below," he said.

In such mountainous regions, it is also very challenging to set up the logistics to extinguish a fire before it spreads over a large area: "For example, there must be a spot on the river where it is dammed, and water can be filled into collapsible containers for the helicopters." At the same time, a shuttle service with fire trucks is needed to fill water on site into an "intermediate basin" into which the fire hoses for firefighting are inserted on the ground.

Rapid extinguishing is only possible with the very well-established and dense network of local volunteer fire brigades in Austria, said Kraxner: "In other countries like South Korea, although they are equipped with even larger and better equipment like firefighting planes, they would probably only be able to stop such a forest fire much later because it takes far too long for the professional fire brigade to reach the affected area from the cities over much longer distances."

Significant Increase in Forest Fire Areas?

In the short term, the forest fire risk can actually only improve through more favorable weather conditions, meaning fewer prolonged high-pressure periods in the summer. There should be less of what is praised on the radio and television as "great swimming weather." In the medium to long term, the human-caused climate crisis must be curbed, said Kraxner: "To do this, at least the two-degree target must be achieved directly, meaning not allowing the temperature curve to rise more than two degrees Celsius compared to pre-industrial times." If greenhouse gas emissions and thus temperature increases are not stopped quickly, forest fire areas would double or triple by the end of the century according to model calculations.

Additionally, more awareness of the specific forest fire risk among the population and effective warning measures are needed, explained the expert. This would include early and year-round education by foresters and fire brigades starting in kindergartens and schools. Consideration should also be given to warning systems on hiking trails and forest roads, where the fire risk could be displayed in traffic light colors. In cases of extreme danger, even area-specific closures could be considered.

In the future, improved aerial surveillance measures will likely be necessary to quickly detect fires, said Kraxner: "For example, with satellites, cameras on towers, and drones that fly over the entire area controlled by artificial intelligence."

(APA/Red)

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