HexFire Model Notes

The original version of HexFire was described in the 2022 paper published in Land.

The current version of the HexFire model includes the following enhancements:

• HexFire now works correctly if the Fuel Barriers barrier map is a time series containing multiple images.

• The Fuel Breaks hexmap is no longer intended to be binary (0 vs. 1).  Previously, all fuels in the Relative Flammability hexmap were removed from any hexagon that had a nonzero value in the Fuel Breaks hexmap.  In the latest version of HexFire, values in the Fuel Breaks hexmap are used as coefficients that modify the Relative Flammability hexmap scores.  The coefficients used are actually set to 1.0 - X, where X is the score of a hexagon in the Fuel Breaks hexmap.  This ensures that a value of zero in the Fuel Breaks hexmap has no impact on fuel availability, while a value of 1.0 results in 100% of the available fuels being removed.