Product Description

In the Southeast U.S. and other humid summer regions Daily Fuels systematically adjusts surface fuel models (Scott and Burgan 2005) based on daily soil moisture values determined by the Keetch-Byram Drought Index (KBDI, Res. Paper SE-38). The KBDI is a soil moisture deficiency index developed to characterize the impacts of drought on the flammability of surface fuel to better reflect increased fire suppression difficulties under unusually dry conditions.

The Daily Fuels, formerly called Daily MoD-FIS, products are generated automatically every evening in the LANDFIRE Map Viewer during a date range when the daily temperatures, on average, reach above the minimum temperature threshold that can support wildland fire, regardless of drought condition.

Concepts initially developed in the 1988 revisions of the National Fire Danger Rating System (NFDRS) and updated in the NFDRS 2016 version to address severe drought in the Southeast U.S. (NFDRS | NWCG) inform the ruleset used to build these daily maps. Fuel bed characteristics for each NFDRS fuel model along with suggested fuel load additions based on severe drought conditions inform the adjustments. KBDI values are used to proportion the additional available fuel loading into four drought increments or classes that are defined by drought severity (none, low, moderate, high). Formulas that calculate fuel weight in proportion to the fuel time-lag size classes for each fuel load addition and account for fuel bed depth (which increases along with fuel weight) are used to maintain the packing ratio of the fuel model.

To help identify the day-of-year in the map file name, here is a Day-of-Year Calendar.

LF Product Used: LF Fire Behavior Fuel Model 40 (FBFM40)

Links to download seasonal mosaics are to the left of each product.

Product Description

Starting in 2017, Seasonal Fuels, formerly called MoD-FIS, has provided adjusted fuel model (Scott and Burgan 2005) map data in the Great Basin and Southwest regions. Currently, fuel model adjustments are based on Landsat Normalized Difference Vegetation Index (NDVI) values acquired from Harmonized Landsat and Sentinel-2 (HLS) imagery. Because fine fuels, like grasses and shrubs, change rapidly based on seasonal moisture, these updates ensure that fire behavior models reflect more recent landscape conditions rather than outdated static snapshots. 

To capture these fluctuations, LANDFIRE produces composited, cloud-free maximum NDVI mosaics (using the 95th percentile) from Harmonized Landsat Sentinel-2 (HLS) imagery across western states four times each fire season. NDVI measures the density of "greenness" on the landscape. High NDVI values indicate lush, live vegetation, while lower values signify "browning" (senescence), dead material, or a lack of vegetation. Every pixel across the region is assigned a specific vegetation "greenness value" and by correlating these satellite observations with existing LANDFIRE herbaceous cover data, we can better quantify the status and abundance of fine fuels in near real-time. Ultimately, these data allow fire managers to adjust/utilize fuel models better suited to current ground conditions.