Fire and Environmental Research Applications Team

The Fuel Characteristic Classification System

The ongoing development of more sophisticated fire behavior and fire effects software along with the implementation of wildland fire emission inventory and large landscape fuel and carbon assessments has demonstrated the need for a comprehensive software system to build, characterize, and classify fuelbeds to accurately capture the structural complexity and geographical diversity of fuel components across landscapes and provide the ability to assess elements of human (e.g. logging slash) and natural (e.g. insect and disease) change.

The Fire and Environmental Research Applications team (FERA) of the Pacific Northwest Research Station Pacific Wildland Fire Sciences Laboratory, U.S Department of Agriculture, Forest Service, has developed a National System of Fuel Characteristic Classification (FCCS) to accommodate this need.

"These outputs can be used by the forest managers/practitioners when developing various management scenarios that could impact timber sales, thinning projects, fuels treatment project activities and fire suppression/pre-suppression activities." (James 2012)

The system offers consistently organized fuels data along with numerical inputs to fire behavior, fire effects, and dynamic vegetation models.

• Users can access a fuelbed from the national fuelbed database within the FCCS that was compiled from published, unpublished literature, fuels photo series, fuels data sets and expert opinion or modify existing descriptions with enhanced information to create a set of fuelbeds to represent a particular scale of interest.
• When the user has completed editing the fuelbed data, FCCS reports the assigned and calculated fuel characteristics for each existing fuelbed component including the trees, shrubs, grasses, woody fuels, litter, and duff.
• The system also calculates a surface fire behavior, crown fire, and available fuel potential index between 0- 9 for each FCCS National or customized fuelbed. These FCCS fire potentials facilitate communication among users and provide an index representation of the intrinsic capacity of each fuelbed for surface fire behavior, crown fire and available consumption of fuels.

FCCS 2.2 improved these issues:

• User input screens are now offered in both metric and English measurement systems.
• Minor corrections were made to the total carbon report and to the fuel model crosswalk calculations.
• FCCS crown fire potentials were amended to more accurately represent recently dead trees with red foliage
• The FCCS batch mode interface was slightly modified to accommodate large batches of fuelbeds and to remove minor errors 
• A combustible-carbon report was added to the batch calculator.

FCCS v. 2.1 improvements were:

1. An important fix to the surface fire behavior equations that improves accounting of the influence of live and dead vegetation on surface fire reaction intensity.
2. Calculation of tree bole biomass and carbon.
3. Minor updates to user screens and reports.

FCCS v. 2.0 enhancements included:

1. The ability for a user to define environmental variables such as moisture
2. Predictions of surface fire behavior, based on both benchmark and user-specified environmental conditions.
3. Reports of carbon storage by fuelbed category and subcategory
4. Predictions of the amount of combustible carbon in each category and subcategory based on selected fuel moisture scenarios.
5. Reports in English and metric units
6. Ability for users to upload photos to represent each fuelbed
7. Batch mode to provide output on a set of fuelbeds.

FCCS v 1.1 offered the following modifications:

1. The program reports predicted surface fire behavior, including reaction intensity (BTU ft-2 min-1), flame length(ft), and rate of spread (ft min-1), under benchmark environmental conditions. Benchmark environmental conditions are:
   • 0% slope
   • 4 mph windspeed
   • Dry fuel conditions (D2L2 moisture scenario after Andrews et al. 2005).
2. Using a dry fuel moisture scenario (D2L2), FCCS suggests crosswalks
   from reported fuelbeds to the original 13 surface fire behavior fuel models
   and the 40 standard fuel models (Scott and Burgan 2005).
3. The FCCS webpage now includes references in PDF format for each of the FCCS fuelbeds.

Team Lead: Roger Ottmar