FW-I-8: Forest fire hazards and forest fires | Umweltbundesamt

FW-I-8: Forest fire hazards and forest fires

Between 1991 and 2017 the areas affected by forest fires declined significantly. Weather-related forest fire hazards remained mostly the same during that period although in some areas they have been increasing. However, in 2018 and 2019 the extreme hot-dry weather pattern was also clearly reflected in the forest fire scenario. There were considerably more and – in the north-eastern Länder – also more large-scale forest fires.

Forest fire hazards rising, forest fires again on the increase

Compared to damage in terms of windblown, wind-broken or pest-infested timber, damage caused by forest fires has so far played a secondary role in most regions of Germany. Brandenburg and regions such as Mecklenburg-Western Pomerania, Saxony, Saxony-Anhalt and Lower Saxony are characterised by a more continental climate. These regions are among the traditional areas of pine cultivation. In summer they are often exposed to extended dry periods, thus putting them at greater risk of forest fires which is therefore a very serious hazard in those regions. In view of the increase in forest fires in the particularly dry and hot years of 2018 and 2019, forest fire risks have again become the focus of greater attention.

Forest fires can be caused by numerous different factors. Major triggers are primarily negligent actions and arson. Whether the first ignition leads to a forest fire depends essentially on the amount of dry, flammable material available on site and thus on the weather pattern and stand structure. However, whether the fire is able to spread depends on wind speeds, fire monitoring and fire fighting capacities – in other words, the time it takes until a fire is tackled as well as the intensity of that fire. Apart from the weather, all the other causal factors usually change more gradually. However, when there are years with abrupt changes – as for instance in 2003 and latterly in the years of 2018 and 2019 – which witnessed frequent and some extensive forest fires – these can often be attributed especially to extreme weather conditions with intensive drought in the spring, summer and autumn months as well as great heat. In cases where these conditions are combined with strong dry wind, such extensive fires spread with particular rapidity.

Up until 2017, according to Federal forest fire statistics, both the number of forest fires and the size of forests affected in Germany declined significantly. The fact that the size of the burn area declined to a greater extent than the number of fires, indicated that there have been improvements in recognising incipient forest fires at an early stage and in containing them successfully. It is true to say that, with financial assistance from the EU, the Federal Länder have in recent years indeed invested considerably in forest fire prevention and in improving the infrastructure required for recognising and tackling forest fires at an early stage. For example, in the eastern Länder which are particularly at risk from forest fires and in the east of Lower Saxony, which is also at risk of forest fires, the old fire watch towers were replaced by digital and remote-controlled optical sensors which facilitate the immediate communication of alerts to forest fire alert centres. Furthermore, traditional precautionary measures such as the installation of firebreaks and water abstraction points were driven forward, and improvements were made regarding public information. While the latter is of importance in respect of negligent actions, it also furthers the willingness of recreation-seeking forest visitors to alert the fire brigade as soon as they spot a fire (typically by using their own mobiles) thus facilitating rapid intervention.

As global warming increases, the forest fire risk is rising too, given that it gets warmer and drier during the critical months. In Germany, the weather-related forest fire hazard is expressed by means of an index value. The higher this value is on the 5-level scale, the higher the forest fire hazard. Over recent years, the time series for the number of days on which high index values were reported at levels 4 and 5 is showing values that are rising significantly. During the particularly hot and dry year of 2018, there were on average 124 days on which the risk levels 4 and 5 were declared in areas which are in general much at risk from forest fires.

In the 1990s, forest fire prevention and fire fighting in the eastern Federal Länder underwent reorganisation which led to the creation of advanced and well-functioning structures. As a result, there was a distinct decline in damage from forest fires recorded during the examined time period up until 2017. However, in the dry years of 2003, 2006, 2015 and 2016 it is possible to see that there were higher risks of forest fires as well as more extensive areas affected by forest fires compared to other, less dry years. In the extremely dry year of 2018 a total of 2,349 ha of forest were either destroyed or severely damaged by 1,708 forest fires nationwide. In Brandenburg the forest fire season was particularly disastrous, with 512 forest fires affecting a terrain of 1,674 ha. The most extensive area affected by fire occurred in the environs of the town of Jüterborg, amounting to 573.72 ha, with privately-owned forest affected particularly badly. The greatest media attention was generated by a forest fire near Treuenbrietzen in August, which was exacerbated by gusts of wind and extinction problems – owing to world war munitions that were still in the ground – thus spreading rapidly to engulf 300 ha. Several villages had to be evacuated. The number of forest fires and affected areas of forest owned by the Federal government doubled in 2018 compared to a rather hot previous summer in 2016.

In 2019 the number of fires was slightly lower – amounting to 1,523 – than in the preceding year – but the area affected by these fires amounted to 2.711 ha. In this year too, the state-owned forest of Brandenburg topped the leaderboard with a total of 1,353 ha. The most extensive fire of that year occurred at the end of June, on the former military exercise terrain of Lübtheen in Mecklenburg-Western Pomerania. The fire extended to a total of 944 ha. The administrative district of Ludwigslust-Parchim declared this disaster. Temporarily, there were more than 3,000 emergency relief respondents involved who came from several Federal Länder. Several adjacent villages with a total of 700 inhabitants had to be evacuated. In the case of the Truppenübungsplatz Lübtheen (military exercise terrain) too, remnant munitions made the fire-fighting efforts more difficult.

As weather patterns give rise to more hazardous conditions, the challenges facing forest fire prevention and control are likely to increase rather than diminish. The continuous improvement of systems as well as the training and organisation of fire fighters have thus become a persistent challenge. Besides, the experience gained in disaster spots such as Treuenbrietzen, Lieberose and Lübtheen makes it ever-more urgent to carry out the clearance of remnant ordinance, thus facilitating any fire extinguishing efforts as required by the extent of a fire.