PROVO — The leaves of 14 shrub species burned in an experiment by Brigham Young University may lay the foundation for quicker predictions on how fast wildfires will burn — key information for wildland managers trying to get ahead of rapidly spreading fires.
As crews try to squelch the Snoqualmie Fire burning above east Layton and the Green Ravine Fire in Tooele County that has charred 1,000 acres, such information could prove invaluable with modeling that aims to give answers in 20 minutes, rather than existing modeling that takes two weeks.
“Very detailed models that already exist take up to two weeks to run on very big computers and by that time, the fire has moved and it’s not in the same place anymore,” said Thomas H. Fletcher, a professor of chemical engineering.
“We’re aiming toward giving answers on how a fire might propagate in the next 20 minutes or half-hour instead of the next two weeks,” he said.
The research, funded by the U.S. Department of Defense and published in the Journal of Analytical and Applied Pyrolysis, grew out of two experiments at BYU’s Fire Research Lab.
In the experiments, Fletcher and the study’s co-authors took the leaves from varying shrub species, such as dwarf palmetto and sparkleberry, and fed them into a device called a “thermogravimetric analyzer,” and slowly turned up the heat.
As they watched the leaves burn, they documented the pace at which the plants disintegrated and the type of chemicals released.
What they found, Fletcher said, is the specific chemistry of the plants plays a big role in the rate of how quickly they break down and combust.
Such information will prove helpful in shaping knowledge about how quickly a hillside might burn as flames move from vegetation to vegetation, researchers found.
Fletcher said the defense department has a keen interest in the science of wildfires because of bases throughout the southeast that occupy or are adjacent to heavily wooded forests with healthy undergrowth.
Like the Bureau of Land Management and the Forest Service in the West, the more information on how a prescribed burn will play out due to humidity, wind and soil moisture is key to keeping them from getting out of control.
“What they like to do is burn the shrubs under the forest every two to four years so it stays a manageable fire,” Fletcher said, adding that those types of fires are good for soil, good for wildlife habitat and good for the forest themselves.
Fletcher hopes to develop an intermediate scale model and focus on vegetation in the West to aid states like Utah.
The studies are especially relevant given Utah’s record-breaking year in 2018 that saw firefighting costs soar to $150 million.
“With all we’ve done to research them, fires are still out of control,” Fletcher said. “Our model can’t prevent a fire, but it can help with decisions on how to manage fires so that when a fire starts, it doesn’t blow up into a huge, uncontrollable fire.”
The Forest Service endured criticism from ranchers and residents alike last summer after the Pole Creek Fire burning in high terrain escalated out of control when it was left to smolder.
Pole Creek merged with the Bald Mountain Fire, leading to the evacuation of thousands of people, smoke-filled skies and dead livestock.
Prescribed fires performed under the right conditions with the right information about vegetation and predicting fire behavior are a critical tool for land managers, Fletcher added.
“There are lots of different people working on this from all angles,” he said. “Even in the West, people are thinking we need more prescribed fires.”