The Forest Canopy Base Height (CBH) layer describes the average height from the ground to a forest stand's canopy bottom. Specifically, it is the lowest height in a stand at which there is a sufficient amount of forest canopy fuel to propagate fire vertically into the canopy. These data are provided for forested areas only. CBH unit measurements are meters * 10.
CBH is generated using a predictive modeling approach that relates Landsat imagery and spatially explicit biophysical gradients to calculated values of CBH from field training sites.
CBH provides information for fire behavior models to determine areas in which a surface fire is likely to transition to a crown fire.
CSVs are used to make Attribute Tables
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.
