Review of wildfire indices: Indices applicable for a Swedish context

Wildfire risk indices can be used in order to be better prepared for wildfires. In Sweden, the Canadian Fire Weather Index (FWI) is currently used to predict fire behaviour based on meteorological data such as wind velocity, temperature and rainfall. Additionally, the HBV model, used to calculate moisture content in soil layers, serves to predict the ignition risk in Sweden. There are however many different wildfire indices used in the world and this study aims to review and identify wildfire risk indices that could also be applicable for a Swedish context. Eleven wildfire risk indices or methods were discovered through a comprehensive literature review. These are described in the report, including required input parameters, information about testing or validation of the method and finally advantages and disadvantages of the method with regards to its potential use in a Swedish context. Four indices were deemed more relevant and suggested for further analysis including evaluation against wildfire data in Sweden: the Fire Weather Index (FWI), the Fosberg Fire Weather Index (FFWI), the Keetch-Byram Drought Index (KBDI) and the Nesterov Index.