Laser-focused on the future: Researchers share new 3D scanning protocol for monitoring fire effects
An image of a forest generated with terrestrial laser scan data points.
According to USDA Forest Service researcher Louise Loudermilk, ecosystem monitoring is like “money in the bank: you don’t need it until you need it.”
Terrestrial laser scanning, or TLS, is a technology that presents new possibilities for making monitoring more efficient, accurate, and affordable.
Loudermilk and forester M.C. Murphy say TLS is especially important for advancing fire science. They, along with a group of fire scientists, managers, and other colleagues, developed a protocol to streamline TLS data capture, processing, and sharing. The protocol and associated research were recently published as a General Technical Report.
The new protocol explains how to use TLS for fast and accurate fire effects monitoring. One application quantifies changes in fuel conditions after a wildfire or prescribed burn. Consistent monitoring also allows scientists to identify trends and develop hypotheses about wildfire risk factors.
As the team discusses in the GTR, other fire effects monitoring systems measure a limited set of variables. These monitoring systems may also require specific skillsets for sampling, such as vegetation identification. These limitations increase the possibility of error and inconsistency, preventing scientists from seeing the whole picture when it comes to the impact of fires on forest ecosystems.
The new sampling protocol lays out steps for efficient, accurate use of the portable, push-button TLS at research field sites. TLS can capture the structure of an entire ecosystem plot in 3D and high resolution, producing images that are both visually appealing and quantifiable. It can even provide precise measurements of up to 200 individual forest characteristics, including surface fuel biomass and the volume of surface, ladder, and canopy fuels. To calibrate TLS estimates, researchers take direct measurements on the plots, including tree height and diameter, woody debris, shrub height, and more.
Forest Service researcher Louise Loudermilk standing with a terrestrial laser scanner in a recently burned forest.
“It’s been a long time coming,” says Murphy about TLS. “Forest Service researchers and collaborators have been working on this technology for over a decade, and it’s an exciting time to be a part of it.”
Estimates of pre- and post-burn biomass are critical inputs for next generation fuel maps and fire behavior models like FastFuels, QUIC-Fire, and BurnPro 3D. The 3D images generated by TLS data points can also be used as a communication tool and to create “immersive forest experiences” that allow scientists to virtually revisit the plots they are monitoring.
Loudermilk and Murphy hope to establish additional TLS monitoring sites to build national data models. This broad-scale system would make monitoring data more consistent across the country. Current data, metadata, and training resources for TLS are available on the Interagency Ecosystem LiDAR Monitoring (IntELiMon) web portal.
For Loudermilk, fulfilling this scientific need makes her work worthwhile. “When you see your research really being applied, and then also getting the feedback to continually make it better ... I mean that’s really rewarding,” she said.
For more information, email Louise Loudermilk at eva.l.loudermilk@usda.gov or M.C. Murphy at mary.murphy@usda.gov.