To create the burn severity maps, Quayle and his colleagues first look into various databases for fires larger than 1,000 acres in the western
Looking at the near and short-wave infrared data on chosen Landsat images, MTBS analysts calculate the Normalized Burn Ratio for each image - a numerical measurement of how much vegetation remains. The Normalized Burn Ratio helps researchers make "apples-to-apples" comparisons of fire severity in the images. Analysts then subtract the post-fire normalized burn ratio from the pre-fire normalized burn ratio to assess the magnitude of change in vegetation. The calculation is similar to measuring a child's height at age three and four and only recording the difference.
The difference in vegetation condition is mapped and color-coded to show the impact of the fires. Green to yellow indicate a low to moderate severity that destroyed relatively less vegetation than red areas, where the fire may have consumed nearly all of the vegetation and left the ground bare. The burn severity map along with the pre- and post-fire Landsat images are available on the MTBS website.
"The big advantage to MTBS is that it maps all large fires on all U.S. lands. It captures public lands and private lands," said Dennison. "That's really nice to have as a researcher because it makes your analysis much more comprehensive."
Dennison and his team at the
He has analyzed over 6,000 fires using the MTBS data and has observed that fires larger than 1,000 acres are increasing by the rate of about six fires per year in the western
The data also has more immediate uses by fire management teams.
Before burn severity maps from the MTBS project, fire calculations and observations were much harder to make. Researchers often gathered data from field or aerial surveys- literally someone looking out over a ridge or in a helicopter and marking areas on topographic maps. Gdula noted that some of his observations would be near impossible to make without the Landsat-derived burn severity maps in MTBS. With Landsat 8, MTBS data continuity will continue for at least the duration of operational Landsat satellites.
"The sheer extensiveness of the data set, having that calibrated data, reaching back in the past and also ensuring that we have the data source well into the future so we can continue this exercise, is an outstanding benefit to resource management provided by Landsat," said Quayle.
Keywords for this news article include: Aerospace, National Parks, Government Agencies, Offices and Entities,
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2013, NewsRx LLC
Most Popular Stories
- Accenture Gets 8 Percent Bump in Q1
- Lockheed Martin Ends Gifts to Boy Scouts Over Gay Ban
- Texting With Vodka: Booze and Social Media Can Mix After All
- Menendez Pushes for Iran Sanctions
- Stripped-Down Defense Bill Creates Winners, Losers
- Mazda Leads the Pack for Fuel Efficiency
- Debt Ceiling Looms Again as Deadline Approaches
- How to Protect Yourself After Target Data Breach
- Deportation Threat Looms Larger Than Citizenship Among Hispanics
- Baucus May Be Next China Ambassador