LANDFIRE (LF) c2001 (National LF 1.0.0) Canopy Base Height Too High for Simulating Crown Fire: Internal and external review has suggested that LF canopy base height estimates are too high for proper simulation of crown fire activity.

Background:

Internal and external review of the canopy base height layer has suggested that, in many areas, LF canopy base height estimates are too high and as a result, fire does not transition from surface to crown in the models as analysts expect. In the LF canopy fuel mapping process, canopy base height is computed by first analyzing tree list data provided mainly by the Forest Inventory Analysis (FIA) program. Depending on the state and vintage in which the data were collected, compacted and un-compacted estimates of height to live crown can be present in the same mapping zone. Compacted height to live crown estimates can lead to overestimates of canopy base height.

Advice:

The LF Fuel Team is investigating the sensitivity of the FuelCalc program to compacted versus un-compacted height to live crown estimates. If users desire to reduce canopy base height values, the LF fuel team recommends using the following equation,

where CBHred is the reduced canopy base height value and CBHorig is the original canopy base height value.

CBHred = int(Ceil(CBHorig * 0.6106))

Conditions vary and data should be evaluated prior to use for fire behavior analyses in new situations.