- Metric Name:  Heavy Fuels

- Data Vintage:  2021

- Unit Of Measure: Short tons biomass/acre

Emissions (on which the modeled PFIRS and Smoke Spotter smoke plumes are based, and which are generated by the BlueSky Playground) are especially sensitive to changes in the coarse fraction of dead wood in the fuel bed, if those fractions are dry enough to be available. It is therefore important to map with project-scale detail where the heaviest fuels might be, so managers have a good estimate for operational smoke management and scenario planning at their project scale, and where perhaps the standard fuelbeds (and emissions estimates based on them) might be underestimating heat and smoke production that can drive unexpected fire behavior, plume loft, and/or smoke impacts.- Creation Method:  The F3 model generated several different raster surfaces of fuel loading estimates of the coarse woody debris by non-overlapping size classes; including 1, 10, 100, 1000-hour fuels (FLOAD_1-5). The model also produced estimates for coarse woody debris of heavy fuels by predefined non-overlapping size classes which are greater than the 1000-hour fuel size (greater than or equal to12”; FLOAD_6-9).

2019 to 2021 Update:  No adjustments were made for 2021 due to uncertainties in conversions based on the limits with which change detection information can quantify the individual components of this metric. For areas with disturbance 2019-2021 (defined as eDaRT MMI greater than or equal to 10% canopy cover loss), fuel values are not represented for 2021 (i.e., NULL). For areas undisturbed 2019-2021, it is a reasonable assumption that heavy fuel values did not change significantly over the course of two years.

This layer is derived from F3 layers (2021) using the following formula:

SUM(FLOAD_5-9)

- Credits:  F3 data outputs, Region 5, MARS Team
USDA Forest Service - Region 5 - Pacific Southwest Region