Geoscience Reference
In-Depth Information
Fig. 3.5
Screen shot of FARSITE software. This is a simulation of a fire on Washington State's
Olympic Peninsula. (Graphics by Jacob Lesser)
agencies. FARSITE uses an intuitive graphical user interface and 2-dimensionl fire
growth and behavior models that calculate wildfire growth patterns across hetero-
geneous landscapes (Fig.
3.5
). It can even incorporate changing weather conditions
and fire suppression activities. This model can be particularly useful for analysts
using multiple scenario runs to explore possible outcomes that might result from
alternative firefighting strategies or changes in the weather.
FARSITE requires raster terrain data representing slope, elevation, and aspect. In
addition this model requires a fuel model data layer using the standard 13 models or
some other similar set of fuel models. FARSITE uses a wave propagation algorithm
based on ellipses to model the progress of the fire through a set of time steps. There
are many other optional inputs including weather variables such as precipitation,
temperature, humidity, wind speed, wind direction, and even cloud cover. Other
biophysical inputs can include canopy cover and fuel moisture. FARSITE outputs
include a set of rasters representing time of arrival, fireline intensity, flame length,
rate of spread, heat/area, reaction intensity, crown fire activity, and spread direction.
The FARSITE support website lists the following capability of the software:
•
Automatically computes wildfire growth and behavior for long time periods
under heterogeneous conditions of terrain, fuels, and weather.
•
Uses existing fire behavior models for surface and crown fires, post-frontal
combustion, and fuel moisture.
