MoD-FIS seasonally modulates fuel model data in the Great Basin and Southwest regions by incorporating seasonal variability of herbaceous cover. These fine fuel measurements are then used to capture changes to fire behavior fuel models based on the current fire season herbaceous production.
Starting in 2017, seasonally modified fuel model data have been developed for the Great Basin and Southwest regions based on the Normalized Difference Vegetation Index (NDVI). Yearly, the most recent 10 years of NDVI from Web-enabled Landsat Data (WELD) are analyzed to determine the average and range of vegetation greenness values for each pixel across each region. These values are correlated with measures of LF herbaceous cover to determine abundance of fine fuels.
A process was developed to create current year herbaceous cover using pre-fire season NDVI imagery and LF data, capturing the green-up of herbaceous vegetation. The resultant updated layers from this process are MoD-FIS Fuel Vegetation Cover and Height (MF_FVC and MF_FVH). This means that MoD-FIS data has capable fuels functionality.
Using the current year herbaceous cover, LF Total Fuel Change Tool can make fire behavior fuel model changes that reflect the current fire season herbaceous cover and resultant fuel availability. Modeling exercises were used to evaluate the seasonal fuel model data. Local fuels experts provided review of the process and resultant data. The final layer from this process is MoD-FIS Fire Behavior Fuel Model 40 (MV_F40).
Where available, LF recommends using MoD-FIS data for fire behavior modeling in prescribed burn plans and during wildfires as this data reflects more current fuel conditions. For risk assessments, users should look to the Fire Behavior Fuel Model 40 annual releases which represent fuel condition averages for a fire season.