The Fire Return Interval (FRI) layer quantifies the average period between fires under the presumed historical fire regime. FRI is intended to describe one component of historical fire regime characteristics in the context of the broader historical time period represented by the LANDFIRE (LF) Biophysical Settings (BpS) layer and BpS Model documentation.
LF Remap FRI is an output of the recently revised Biophysical Settings (BpS) models for LF Remap (LF 2.0.0) and is now provided as an attribute of the BPS spatial layer. In previous versions available to the public, FRI was referenced by Mean Fire Return Interval (MFRI), and was an output of the original BpS models and was provided as a separate spatial layer.
The comma separated value (CSV) file used for the raster attribute table is included in the LF product download in database file (DBF) format.
(Why is the CSV important?)