Towards an integrated forest fire danger assessment system for the European Alps

In recent years the European Alps experienced higher temperatures, more heatwaves, and more severe wildfires. Improving fire danger assessment for these sensitive ecosystems is a core element of future-oriented fire management strategies in the face of climate change. While meteorological systems are common to predict fire danger in many countries, other factors such as vegetation, topography, lightning occurrence and human impact are generally not considered. We introduce an Integrated forest Fire Danger assessment System (IFDS) for the Alpine country Austria that includes i) daily fire weather index data, ii) a countrywide hazard map for fire ignition through human activities, iii) a lightning fire hazard map, iv) a high-resolution fuel type map, and v) a topography-based estimation of the fire hazard. The system was implemented as an online Web-GIS prototype. The objectives of this contribution are to describe the conceptual approach for the IFDS, to understand the predictive power of different data layers in fire danger rating and to identify potential improvements, especially regarding the role of vegetation and human influence. A first validation was done with 2018-2019 forest fire data. Some variants of the IFDS produced better overall prediction accuracy regarding forest fire ignitions compared to common fire weather indices. They typically performed relatively better when considering the number of false alerts as well. However, correlation between larger burned areas and higher index values was low. Conclusions for the implementation of the IFDS in other Alpine countries are discussed and recommendations for necessary and reliable datasets at high resolution are given.