With the height of the 2021 wildfire season on the horizon, the U.S. Geological Survey is working to provide the research and data needed to plan for and respond to wildfire activity.
USGS EROS Supports Wildfire Science through Updates, Upgrades to Landscape Mapping
A recently released document outlines the agency’s five-year strategic plan to address wildfire threats, which will guide research in the development of remote sensing data on vegetative fuel loads and burn severity mapping, models of post-fire debris flow and more.
The Survey employs more than 100 fire scientists across multiple Mission Areas around the country, but in many ways the fire-related work of the USGS Earth Resources Observation and Science (EROS) Center ties nearly all of them together.
USGS EROS is the production facility for the Landscape Fire and Resource Management Planning Tools (LANDFIRE) program, a multi-agency partnership funded by the DOI Office of Wildland Fire and the US Forest Service that provides over 20 geospatial mapping layers across the U.S. and insular areas, from vegetation type and height to fire regimes and capable fuels data.
It’s also the production engine behind Monitoring Trends in Burn Severity (MTBS), which maps fire perimeters and burn severity across the U.S. from 1984 through the present. MTBS work is done in partnership with USFS personnel at the Geospatial Technology and Application Center (GTAC). The Burned Area Emergency Response (BAER) program is supported by scientists across the USGS, but EROS carries the responsibility for generating the Burned Area Reflectance Classification (BARC) maps for wildfires occurring on DOI lands. The BARC maps form the basis for soil burn severity maps that are used to inform post-fire mitigation plans developed by the BAER teams.
USGS EROS Geographer Birgit Peterson was a co-author of the strategic plan. Part of the work involved reaching out to the fire science community to ask questions about the available USGS fire science data. Peterson helped to organize some of those stakeholder meetings, looking for guidance from users on what is or isn’t working for them.
“The idea was to bring together USGS fire science to showcase what we can do and to engage stakeholders to see if they were using USGS fire science, how they were using it, and if they weren’t using it, why?” Peterson said. “Was it because they weren’t aware of it, or was it because what’s being done isn’t fitting the bill, so to speak?”
The surveys showed that the USGS is recognized as a leader in fire science. Users wanted more and better modeling for fires, however, and easier data access.
Peterson and others at USGS EROS are working to make that happen. Data teams are working to deliver fresher and more reliable mapping data to fire scientists and teams in the field at a much faster pace by leaning on new data sources, machine learning and artificial intelligence.
Peterson is among the USGS scientists investigating how to improve measurements for the height of a tree canopy, for example, using tools like terrestrial light detection and ranging (lidar) data, as well as data from satellite sensors used in NASA’s GEDI and ICESat-2 missions. USGS EROS is also looking into data from NASA’s Soil Moisture Active Passive (SMAP) mission, which measures soil moisture and freeze/thaw cycles, and from NASA’s ECOSTRESS mission, which measures plant temperature.
That work typically involves pilot projects. One such pilot is taking place in the Black Hills of South Dakota. Teams from USGS EROS collected on-the-ground measurements after the Legion Lake Fire of 2017 that will help them to better understand how different remote-sensing based height products scale from local to regional extent and how might best be integrated with spectral-based burn severity estimated derived from Landsat imagery. They physically measured trees, Peterson said, but they also gathered terrestrial lidar and available airborne lidar to get as much plot detail as possible.
Now the group is working to combine that information with data gathered from miles overhead by GEDI or ICESat-2 to create regional-scale maps. The question, Peterson said, is “what aspects of what we’re looking at scale well, and which ones do not scale well.”
Vegetation height and composition are critically important to fire science. Without the benefit of on-the-ground measurements for the entire country, remotely sensed height data from sensors like GEDI hold the promise of improving imagery-based, national-scale mapping efforts.
“If we learn something useful from it, maybe it can be useful in our building and beyond,” Peterson said. “In many cases, it’s looking at small scale studies and trying to figure out what these data have to offer. We know what they do in theory, but are they really going to address some of the questions that you have?”
Ultimately, the goal is to deliver even more detailed and relevant information to firefighters and land managers in fire-prone areas—information that’s meaningful to the protection of lives, property, and ecosystems.
The future involves not only improving LANDFIRE’s quality, but also speeding up the release of fresh data. LANDFIRE 2019 Limited is a step toward a goal of annual updates, set for a release in summer 2021. It adds contributed disturbances from 2017-2019 into several—but not all—of the LANDFIRE’s mapping layers. Over the next few mapping cycles, the program will move toward more robust updates, eventually offering full, annual updates from the previous year derived from Landsat and contributed landscape disturbances.
To improve access to other remotely sensed data sources, Peterson’s USGS EROS colleague Kurtis Nelson is leading the charge to create a burn severity portal that will serve as a sort of one-stop shop for products like MTBS or BAER.
“There’s always work being done (on the data access) side, as well,” Peterson said.