MODELING A HISTORIC FOREST FIRE USING GIS AND FARSITE

Recent major wildfires may result from a combination of climate change and fuel buildup due to fire exclusion policies of the last century. Are such fires unique to the forests and climate of the 21st century or are they similar to historic fires? Historic fires are recorded primarily by eye witness accounts which seldom contain information needed to examine them with modern fire management tools. The September 1, 1894 fire near Hinckley, Minnesota has well documented accounts from many survivors that allow position of the flame front to be established for a number of times throughout the fire. These accounts allowed us to calibrate a FARSITE model to represent the progression of that fire. FARSITE is a modern fire spread rate simulation model. It requires spatial layers of elevation, slope, aspect, timber type, derived layers of fuel type, canopy cover, stand height, canopy base height, canopy bulk density, duff and coarse woody debris. In this paper we will discuss how we were able to combine present GIS data, historical map data, and present ecosystem properties to provide data needed for these layers. GIS output of FARSITE spread predictions were used to match flame front position to eyewitness accounts and model parameters (primarily, wind speed and direction and fuel model spread rate adjustments) were altered to produce a flame front location and time that matched eyewitness location and timing.