17 years of wildfire detection and management supported by an optical sensor system: field report from Germany’s Brandenburg national forest, one of Europe’s top wildfire regions at risk

Abstract

When it comes to wildfires in Europe, people usually think about southern countries, such as Spain, Portugal or Italy. However, parts of northern and northeastern Germany have been classified by the European Union as top regions at risk of wildfires. The state of Brandenburg has more than one million hectares of forest, which is equal to 37% of the state area. Dry and sandy soil means poor growth conditions, and only undemanding plants may be cultivated with reasonable effort. That’s why monoculture pine forests make up 78% of all woods in this area. Precipitation easily permeates the sandy soil while fires burn the extremely dry ground, fueled by liquid resin, needles and forest litter that does not decompose. This is particularly problematic since Brandenburg was a battleground of the final phase of World War II and a military training ground for more than 100 years. The region was contaminated by hundreds of thousands of tons of unexploded artillery grenades and bombs. About 36% of the entire state and 50% of the woodland is still heavily polluted with old weapons posing major risks to the civilian population and particularly to fire fighters. Early wildfire detection is crucial under these circumstances, and generations of human fire spotters worked for decades using a dense network of watchtowers. Due to extremely high maintenance costs of these watchtowers and due to difficult labor legislation, the automatic remote surveillance system FireWatch was introduced in 2001. Today human fire spotting is history; 108 sensors are operating successfully and have proven to be technologically efficient. Plenty of detailed statistics haven been collected for decades giving evidence that the burnt area per hectare of a fire has been reduced tremendously since the installation of FireWatch and that the system has clearly outperformed the human spotter from a long-term perspective.