Sensitivity of a fire behavior model to changes in live fuel moisture

Fire behavior models are used to assess the potential characteristics of wildland fires such as rates of spread, fireline intensity and flame length. These calculations help support suppression strategies while keeping fireline personnel safe. Live fuel moisture is an important component of fire behavior models but the sensitivity of existing models to live fuel moisture has not been thoroughly evaluated. We use the BehavePlus modeling system to estimate key fire behavior values over a range of live fuel moistures using all 53 fuel models. We show that fire behavior characteristics are highly sensitive to live fuel moisture but that the response is dependent on the proportion of live fuel in the particular fuel model. In some cases, small changes in live fuel moisture elicit drastic changes in predicted fire behavior. We suggest that model sensitivity to live fuel moisture should be considered when making decisions based on model-predicted fire behavior.