The effect of fuel bed height in grass fire spread: addressing the findings and recommendations of Moinuddin et al. (2018)

Abstract

A recent numerical simulation study by Moinuddin et al. (2018) determined that over a specific range of Froude numbers defined by them as ‘plume mode’, grass fuel height has a strong inverse effect on the rate of fire spread in grasslands. They then suggested that a relationship for effect of fuel height derived from their simulation results could be used to support fire management decision-making. The present analysis used fire spread measurement data from two outdoor experimental burning studies in grass fuels where an explicit control of fuel height was imposed to verify the realism of their results. It was found that a reduction in grass height, with or without removal of the cut fuel and regardless of the Froude number, led to a significant reduction in rate of fire spread, a result opposite to the simulations obtained by Moinuddin et al. (2018).