The High Park wildfire in Colorado last month covered both rugged terrain and populated areas, moving in a particularly erratic way, at least partially because of the damage already done by bark beetles in the area. The resulting dead trees create more fuel more forest fires and change the forest canopy, which makes it more difficult to fight the fires.
A new computer modeling software called HIGRAD/FIRETEC has been developed through a partnership between the US Forest Service Rocky Mountain Research Station and Los Alamos National Laboratory (LANL) to help predict wildfire behavior in bark beetle-ravaged areas.LANL explains, "HIGRAD/FIRETEC is a physics-based, 3-D computer code designed to simulate the constantly changing, interactive relationship between fire and its environment. It does so by representing the interactions among fire, fuels, atmosphere and topography on a landscape scale. HIGRAD is a computational fluid-dynamics model that represents airflow and its adjustments to terrain, different types of fuel (vegetation) and the fire itself. FIRETEC combines physics models that represent combustion, heat transfer, aerodynamic drag and turbulence."
The software models fire behavior using data that researchers have collected in forests where bark beetles have done their damage. Their research is focusing right now on what fire behaviors are caused by the increase in dead fuel and what behaviors are caused by the changes in the forest canopy which allow high winds to push the fire more easily.
More importantly, HIGRAD/FIRETEC simulates the dynamic processes that occur within a fire and the way those processes feed off and alter each other. So, the models show how when a fire hits a patch of dead trees it accelerates tree-top fires that can consume live trees. Previous models have assumed a uniform moisture content throughout the forest, making them ineffective for forests where bark beetles have been
By figuring these differences out, firefighters will be better prepared to fight these more dangerous and erratic fires.