Hazardous Fuels and Vegetation Treatment Processes and Tools
Under Development by R5, PNW Research Station and RM Research Station
1. Tool Name : Fire Effects Tradeoff Model (FETM)
2. Brief Description of Tool: FETM is a landscape-scale disturbance model designed to simulate the
effects of alternative land management practices on future landscape conditions over long periods of
time and under diverse environmental conditions, natural fire regimes, and fuel and fire management
strategies. The model is based on a classical stationary Markov formulation (Feller 1968), which
utilize matrices of empirically determined probabilities to predict vegetation class replacement, and
therefore composition, over time.
FETM accounts for both natural and management related disturbances. Natural disturbances include:
wildfire (for different fire intensity levels), insects and disease, and other user-specified disturbances.
Management related disturbances include: harvesting, mechanical fuel treatments, prescribed fire,
firewood collection, and other user-specified activities. Management activities and acres are
scheduled in FETM. The user enters the number of acres by fuel characteristic class per year or range
of years.
Disturbance effects, whether natural or man caused, are represented as a change in surface loading, a
change in fuel bed configuration, a change in vegetation age or structure, or any combination of the
above.
FETM is dynamic, predicting annual changes in landscape composition and effects over any time
period ranging from one to 300 years. For each independent run, the starting composition in any year
of simulation is linked to the previous year’s results. The model is stochastic; random variables
include wildfire frequencies in each of the four National Fire Danger Rating System (NFDRS;
Bradshaw and others 1983) weather classes, and the potential wildfire size in the event that fuel
loadings exceed the range of historical variability. FETM is a non-spatial model, capable of predicting
disturbance effects within an area by vegetation class, but not capable of predicting where those
impacts will occur on the landscape or whether the impacts are contiguous or dispersed.
One feature that differentiates FETM from other landscape models is its use of fire behavior
algorithms to determine the size and intensity of fire events. Rather than relying exclusively on
historical fire data as the basis for determining future fire sizes and effects, FETM integrates aspects of
physical fire behavior modeling into its simulations. This integration of classical fire behavior
modeling into landscape simulation modeling allows FETM users to evaluate the consequences of
changes in the fire environment (e.g., fuel loading, canopy structure, weather, topography) on wildfire
area and other fire effects. For example, FETM can evaluate the effect of a change in surface fuel
loading or stand configuration on the potential for crown fires. Integration of fire behavior modeling
also offers an opportunity to quantify the level of fuel consumption and smoke emissions over time,
which is an increasingly important factor in implementing management activities across the landscape.
3. Scale Tool is Applicable: FETM was designed as a landscape-scale model. A rule-of-thumb is that
the modeling domain should be not less than 10 times the area of the largest fire that is expected to
occur within the simulation period.
Disclaimer: The views in this report (presentation) are these of the author(s) do not necessarily represent the views of the
Forest Service.
4. Analyst Requirement: Medium (M) – Requires a mid-level analyst or GIS specialist in order to run
the model or tool or make it usable for local situations. More information on team requirements is
available in the FETM users guide available at:
http://www.fs.fed.us/r6/aq/fetm/FETM_Downloads/Manual_060403.pdf
5. Data Inputs: Inputs include:
• Delineation of Administrative Units included in analysis area
• PCHA and IIAA database files for each included Administrative Unit (major source of required
input data for FETM)
• Initial acres by fuel characteristic class (FCC)
• Fuel bed description for each FCC
• Stand description (if applicable) for each FCC
• User-specific disturbance effects pathways and coefficients
• Mean fire frequency for low, moderate, high, and extreme NFDRS weather classes
• Relationship between expected final fire size and rate of spread from wildfire case history data
• Description of alternatives, including fire suppression program option
• Schedules of treatment activities, including prescribed fire
• Simulation time period
• Number of model iterations to average results over
All of these data are normally available at the local level. No specialized pre-processing of input data
is required.
6. Model Outputs: Graphical and tabular model outputs include, but are not limited to, the following:
• Annual landscape composition (acres by FCC)
• Annual wildfire acres, total and by fire intensity level
• Annual fuel treatment acres (both targeted and accomplished)
• Annual smoke emissions from wildfire, prescribed fire (seven pollutants)
• Smoke emissions by prescribed fire treatment intensity in any future year
• Net present value of future costs and benefits from wildfire and prescribed fire
7. Application of Model for Fuel Treatment work: FETM was designed to evaluate the effects of
alternative land management practices, including fuel treatments, over long periods of time and under
diverse environmental conditions and natural fire regimes. FETM was the dynamic simulation model
used to evaluate fuel treatment alternatives for the Boundary Waters Canoe Area Wilderness Fuel
Treatment Final Environmental Impact Statement, Superior National Forest, Minnesota (2001).
8. Linkage to Other Models/Tools: FETM has the capability to link up to Administrative Unit-specific
PCHA and IIAA database files. In addition, FETM utilizes the key functionality and algorithms from
several other state-of-the-science models, including: CONSUME 2.1 (fuel consumption and
emissions), CrownMass (predicting canopy structure and loading), BEHAVE (predicting crown fire
rates of spread), PCHA (provides access to fire weather and history data; algorithms used to compute
new weather-based outputs), IIAA (provides access to fire suppression organization costs and benefits
data; algorithms used to compute new breakpoint rates of spread for fires burning in different
Disclaimer: The views in this report (presentation) are these of the author(s) do not necessarily represent the views of the
Forest Service.
derivative fuel models), and NFDRCalc (algorithms used to compute NFDRS fire output parameters),
and others.
9. Partners: FETM was developed in part by a grant from the U.S. Joint Fire Science Program and in
partnership with the USDA Forest Service, Pacific Northwest Region (Air Quality and Fire and
Aviation Management Programs), and the Oregon State Office of the Bureau of Land Management,
U.S. Department of the Interior.
10. Current Status: FETM is currently available for use by any organization or individual, public or
private. A complete description of FETM, along with the model setup files, a user guide, technical
documentation, brochure, and a series of currently published papers, may be found at:
http://www.fs.fed.us/r6/aq/fetm.
11. Training Availability: Training is available on an as-needed basis. For more information on
training, please contact John Szymoniak or Mark Schaaf at the numbers below.
12. Tool Contacts: John Szymoniak, Technical Transfer Specialist, PSW Riverside Fire Laboratory,
3833 S. Development Avenue, Boise, ID 83705, phone (208) 387-5748, email jszymoniak@fs.fed.us;
or Dr. Mark Schaaf, Program Developer, Air Sciences Inc., 421 SW 6th Avenue, Suite 1400, Portland,
OR 97204, phone (503) 525-9394 ext. 11, email mschaaf@airsci.com.
13. Example of Model/Tool Application: Two example FETM applications are found on the FETM web
site at: http://www.fs.fed.us/r6/aq/fetm/Applications.htm. One of the example applications is the
Boundary Waters Canoe Area Wilderness Fuel Treatment Final Environmental Impact Statement,
Superior National Forest, Minnesota (2001). The other is an analysis of fuel treatment and fire
suppression strategies for the Angeles National Forest, California (2004). FETM is currently being
applied at numerous other sites around the contiguous United States and Alaska.
Disclaimer: The views in this report (presentation) are these of the author(s) do not necessarily represent the views of the
Forest Service.