The 40 Scott and Burgan Fire Behavior Fuel Model (FBFM40) layer represents distinct distributions of fuel loading found among surface fuel components (live and dead), size classes, and fuel types.
This set contains more fuel models in every fuel type (grass, shrub, timber, slash) than Anderson's set of 13. The number of fuel models representing relatively high dead fuel moisture content increased, and fuel models with an herbaceous component are now dynamic, meaning that loads shift between live and dead (to simulate curing of the herbaceous component) rather than remaining constant.
FBFM40 was produced through a series of workshops held across the nation with fire and fuels specialists to determine surface fuel model rule sets using unique combinations of existing vegetation type, cover, and height. The resultant spatial arrangement of surface fuel models are known as the calibrated FBFM40 layer.
The FBFM40 layer can serve as input to wildland fire prediction models.
Attribute tables for LANDFIRE grid data, served in CSV (comma separated values) file format, are available on the Data Distribution Site and landfire.gov. Generally, these attribute tables provide information pertaining to the grid class value along with class descriptions or labels for these values. Attribute tables, such as the Existing Vegetation Type, provide additional attribute fields that can provide crosswalk links to other classification themes. Color mapping fields are also provided within the attribute tables, providing a standardized, consistent LANDFIRE color mapping schema for these data layers. The attribute files are in comma separated value (csv) format that can be easily converted to other formats to meet user needs.
The attribute tables are provided as a convenience as calculations with grid data will automatically drop attributes. For example, if a grid is clipped, the rowid, value, and count are the only attributes retained. Attribute fields can be reattached to the grid using a join attribute function having the "value" attribute as the link.