Modelling fuel moisture under climate change

Purpose - Fuel moisture is an important determinant of fire behaviour. Changes in climate will result in changes in fuel moisture and this will impact fire management by modifying the length and severity of the fire season and by changing opportunities for prescribed burning. This paper aims to examine the effect of climate on fuel moisture in Eucalypt forests. Design/methodology/approach - A climate model is used to predict weather for five Australian cities from 1961 to 2100 under a high-emissions scenario. Time series are extracted from the model and used as boundary conditions for a process-based fuel moisture model. Fuel moisture predictions are used to examine two management variables: the number of days suitable for prescribed burning in spring, and the number of days when fire could burn in summer. Findings - There were significantly more fire days in warmer-drier years. The number of days with extremely low fuel moisture was also higher in warmer-drier years. Variation in the number of burning days was narrower than for fire days but the number of burning days was lower in warmer-drier years. The lower number of burning days in warm years was due to a higher rate of fuel drying in these years. Research limitations/implications - Analysis was limited to Australian locations. In future, the work should be expanded to include Eucalypt plantations on other continents. Practical implications - The changes predicted will require changes to fire management practices, particularly the timing of prescribed burning. Originality/value - This paper uses a new, physically based method to examine the effect of climate change on fuel moisture. It will be useful to fire managers seeking to adapt to a changing climate.