Fire and Environmental Research Applications Team

FCCS Restrictions and Limitations

Mapping FCCS for Fire Behavior

FCCS makes point-based calculations of fuel characteristics and potential fire behavior and does not simulate fire spread across landscapes. However, because fuelbeds have no inherent scale, FCCS outputs can be easily mapped in GIS by assigning polygons or raster cells with a unique fuelbed identification number. 

When mapping FCCS predictions across landscapes, it is important to consider that environmental variable inputs including moisture content (%) of live herbaceous and shrub fuels, 1-hr, 10-hr and 100-hr woody fuels, midflame windspeed, and slope gradient have a substantial impact on FCCS predictions of surface and crown fire behavior.  The default environmental variable scenario in FCCS is for dry fuel conditions (D2L2: 90% shrub FM, 60% herbaceous FM, 6% 1-hr FM, 7% 10-hr FM, and 8% 100-hr FM), 4mph midflame wind speeds, and 0% slope. 

If environmental conditions vary across your landscape, you will need to create custom fuelbeds with custom environmental variables.  The FCCS batch mode is best suited for large numbers of fuelbeds and can accommodate custom environmental variables.

Fuelbed Crosswalks and Environmental Conditions

As part of the surface fire behavior outputs, FCCS provides a crosswalk to one of the 13 original fire behavior fuel models and one of the 40 standard fuel models (Scott and Burgan 2005).  This is a static crosswalk based on predicted surface fire flame length and rate of spread under an input set of environmental variables (fuel moisture, midflame windspeed, and slope gradient). 

The crosswalk is invalid under any other environmental scenario and is generally not appropriate for simulating fire spread across landscapes (as in FARSITE). Fuel model crosswalks may be used in FlamMap as long as input wind, slope and fuel moistures remain the same as in the original FCCS prediction.