PLUMES ABOVE LINE FIRES IN A CROSS-WIND

A model for the plume above a line fire in a cross wind is constructed . This problem is shown to reduce to numerically solving a system of 6 coupled ordinary differential equations for given initial conditions that depend upon the fire characteristics. The model is valid above th e flaming zone and takes inputs such as the width, velocity and temper ature of the plume at a given height above the flaming zone, Different horizontal ambient wind velocities are allowed for and a comparison i s made between some of these representative wind profiles. The plume t rajectory, width, velocity and temperature are calculated for these di fferent representative velocity profiles. This model has application t o the calculation of temperature-time exposures of vegetation above li ne fires and hence can be used in models that predict effects such as leaf scorch and canopy stored seed death. On a larger scale it has app lication to the problem of tracking burning brands which can cause spo tting ahead of the fire.