Provisional IA

Provisional Initial Assessments

These products were produced using the methods of the Monitoring Trends in Burn Severity Program (MTBS), however this fire may not meet the criteria for an MTBS initial assessment. The MTBS Program assesses the frequency, extent, and magnitude (size and severity) of all large wildland fires (wildfires and prescribed fires) in the conterminous United States (CONUS), Alaska, Hawaii, and Puerto Rico for the period 1984 and beyond. MTBS typically maps fires using an initial assessment (immediately after the fire) or an extended assessment (peak of green the season after the fire) for low-biomass and high-biomass fires respectively. Refer to MTBS.gov for more information on MTBS methods and criteria. Fires reported as greater than 40,000 acres in burned area and/or are of particular significance are mapped on a provisional basis, using an initial assessment strategy regardless of vegetation type or density, provided suitable imagery is available. Once imagery for an extended assessment is available, this fire will be assessed under the MTBS program and an official MTBS initial or extended assessment product will be published under that program.

Timeline

3 to 6 weeks after fire containment

Data Available

2020-2023

Audience

This product is provided to users of burn severity data that require access to burn severity assessments for significant fires faster than those produced by the MTBS protocols. The MTBS program typically releases data 6 to 12 months after the event. This product provides a provisional product to bridge that release delay.

Mapping Method

Burn Severity layers are created by first calculating spectral indices from pre- and post-fire satellite imagery that are sensitive to changes caused by fire.  The two images are then subtracted showing the difference between them which is then thresholded into burn severity classes.

Deliverables

  • Pre- and post-fire satellite imagery
  • Burn area boundary shapefile
  • Differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (continuous)
  • 6-class thematic thresholded dNBR
  • Metadata
  • Visualization products