Burning Index (BI) is a number used by the National Oceanic and Atmospheric Administration (NOAA) to describe the potential amount of effort needed to contain a single fire in a particular fuel type within a rating area.
The National Fire Danger Rating System (NFDRS) uses a modified version of Bryam's equation for flame length – based on the Spread Component (SC) and the available energy (ERC) – to calculate flame length from which the Burning Index is computed.
is the Burning Index scaling factor of (10/ft).
Therefore, dividing the Burning Index by 10 produces a reasonable estimate of the flame length at the head of a fire.
A unique Burning Index (BI) table is required for each fuel model.