FAQs

RAVG assessments are based on regression equations that relate imagery-derived indices to field-based burn severity measures for forest vegetation. They are not calibrated for other vegetation types and other disturbances. Although RAVG data may indicate the relative severity of other disturbances or in other vegetation types, the burn severity values cannot be directly applied to such cases.

For a list of standard RAVG data products, see the Products section on the Background, Products and Applications page. The metadata file associated with each RAVG assessment also includes product descriptions.

For MTBS data, go to www.mtbs.gov(link is external).

For BAER-related data, go to https://burnseverity.cr.usgs.gov/baer/baer-imagery-support-data-download.

The RAVG, MTBS and BAER Imagery Support programs are three distinct but related post-fire assessment activities managed, at least in part, by GTAC. MTBS is conducted jointly with the USGS EROS Center. For BAER imagery support, GTAC responds to requests from Forest Service BAER teams and EROS responds to requests from Department of the Interior teams. The three programs have many similarities, such as the use of moderate resolution multispectral satellite imagery, but differ in their methods and protocols, as well as in their intended audiences. For more information about the MTBS and BAER imagery support programs, see https://www.mtbs.gov and https://burnseverity.cr.usgs.gov/baer respectively.

For annual national mosaics of raster products and combined perimeter layers, see the National Datasets section of the Data Access page.

Forest Service units can request non-standard assessments by contacting the RAVG program (see the Contact Us page). Requests will be considered on a case-by-case basis.

There are several possible reasons for a fire being absent from this website:

1. The fire doesn't meet program criteria. Generally only wildland fires that meet the standard RAVG criteria have data published on the RAVG website. The primary criterion is that the fire include at least 1000 acres of forested National Forest System land (500 acres for Regions 8 and 9).

2. Suitable imagery is not yet available. Sufficiently clear pre- and post-fire imagery is required for each RAVG assessment. In order to improve the assessment quality, the analyst may choose to wait for near-ideal post-fire imagery rather than using an earlier but less-than-ideal scene. Most fires are assessed using imagery acquired no later than 45 days after fire containment; however, for fires that burn into the Fall or that occur during winter or early Spring, the presence of snow and/or excessive terrain shadows may dictate waiting until late Spring or Summer for imagery. The Mapping Status page shows the status of fires that are expected to meet RAVG criteria but that have not yet been assessed.

3. The fire is included with another assessment. If two or more large fires merge and are assessed as a single burned area, they will appear in the database under the name of only one of the original fires. Similarly, fires in a named complex may appear under the name of the complex or under individual fire names.

4. The fire pre-dates RAVG. The RAVG program was implemented on a national scale in 2007. Fires from years before 2007 are not included in the RAVG database.

5. The fire severity was extremely low. Occasionally the signature of a low-severity fire will be undetectable in satellite imagery. This is more likely for a surface fire under closed canopy cover. In this situation, the RAVG analyst may choose not to conduct the assessment.

For additional information about missing fires, contact the RAVG program (see the Contact Us page).

Use the data query tool on the Data Access page to search for RAVG data by fire name. If multiple fires merged into a single footprint, they may be published as a single dataset under the name of one of the original fires. Likewise, if the fire was part of a named complex, it may be published under the name of the complex.

The colors represent distinct ranges of the several burn metrics (e.g., 75-100% basal area loss). "Warm" colors (i.e., reds and yellows) indicate greater change and "cool" colors indicate lesser change. Color definitions for each class are available in the attribute table for GeoTIFFs and in legends associated with other graphic products.

"Classic" versions (2021 and earlier)

Current (CVD-friendly, Section 508 update)

As of the 2022 fire season, classified RAVG products use a new color scheme designed to meet the intent of Section 508 of the Rehabilitation Act. Specifically, it is intended to be more accessible to those with common color vision deficiencies ("color blindness"). As before, higher values are represented in "warm" colors (i.e., reds and yellows) and lower values in "cool" colors (i.e., blue and blue-green colors). Color definitions for each value are available in the attribute table for GeoTIFFs and in legends associated with other graphic products.