PARENT SESSION
Oral Session #55: Fire Ecology. Presiding: M. Moritz.
Wednesday, August 8, 2001. 1:00 PM to 5:00 PM. Hall of Ideas H.
Interactions of wildfire components: Modeling the Cerro Grande Fire.
Koch, Steven1, Balice, Randy1, 1
ABSTRACT- Last summer's 47,000 acre Cerro Grande Fire provided a natural experiment to better understand the abilities and limitations of a fire behavior model (FARSITE) to predict fire spread and fire characteristics in a complex ecosystem. Using fuel loadings and forest structure data collected over three years, we tested the ability of the model to generate a catastrophic wildfire. We did this by examining the sensitivity of the system to changes in selected model parameter settings. The wind speed, the distance between the ground and the base of the live fuel canopies, and the fuel model were varied as part of this analysis. Other parameters, including slope, canopy cover, crown bulk density, and canopy height were held constant. The results of the sensitivity analysis display a clear interaction between the windspeed, the crown base heights, and the fuel model. For instance, continuous canopy fires were observed for Fuel Models 1 and 2 with short distance between the ground fuels and the crown fuels (less then 1 m) and high wind speeds (24 mph), but not under other conditions. The FARSITE model is widely used in wildfire fighting operations and prescribed fire planning. Understanding model behavior under complex conditions leads to improved practical application and improved understanding of wildfire component interactions.
KEY WORDS: wildfire, FARSITE, fire behavior, modeling