GEORGETOWN, Calif. — A wave of fire swept through a Sierra Nevada forest, billowing smoke and leaving charred vegetation — all under heavy-duty drone surveillance. Surrounding equipment caught a sample of charred particles jetting into the air.
The age-old practice of clearing forests of small trees, bushes, and other fire-starting sources, routine burning has received a 21st-century upgrade.
As climate change depletes land and increases the risk of wildfires, scientists are using cutting-edge technology and computer modeling to make controlled, low-intensity burns safer and more effective, helping to protect neighborhoods. We are starting to cause less disruption to the community.
As Tirtha Banerjee of the University of California, Irvine, watched a pile of dead tree branches go up in flames, she said, “Fire has civilized us, but we don’t fully understand it yet.
Although prescribed burning is effective in sustaining forests, it is difficult to enforce. It is costly, labor intensive and subject to narrow windows in good weather. And even well-planned burns can be disastrous, like when gusts turned a fire started by the U.S. Forest Service this spring into the largest wildfire on record in New Mexico. .
Scientists think we can do better. Several teams recently converged at the Blodgett Forest Institute northeast of Sacramento. The area is home to towering ponderosa pines, Douglas firs and incense cedars. Blodgett’s planned open burning provided a unique opportunity to gather data on the ground. The researchers packed the car with GoPro cameras, drone-mounted sensors to map terrain in detail, sonic anemometers to measure wind speed, and a variety of machinery. Collected airborne particles.
Researchers have long deployed sophisticated techniques to study the behavior of wildfires, but they often ask questions specific to prescribed fires, such as whether it is necessary to clear debris with chainsaws or bulldozers beforehand. Few people looked into it. Berkeley.
Pre-thinning allows air to blow through during combustion, creating a hotter flame that can be difficult to control. But it also helps burns consume more of their remaining feed, creating a longer-lasting buffer against wildfires.
“I really think everything about prescribed fire should be explored,” Dr. Banerjee said.
When Prometheus stole fire from the gods and gave it to humans, he probably had no idea how difficult it would be to work with it on a planet heated by burning fossil fuels.
Global warming has brought more extreme hot and dry conditions that can turn wildfires into deadly catastrophes. It burned down acres, but half a century ago, when the Forest Service and other agencies first developed mathematical models to predict how wildfires would break out, it gave scientists a glimpse of the big picture. it was not the department. expand.
James T. Landerson, a geoscientist at the University of California, Irvine, said scientists were “totally caught off guard by the speed of change.”
The Forest Service admits it’s not keeping up with global warming. agency research An investigation into an ill-fated wildfire in New Mexico this spring found that, despite being well planned, the resulting fire was more dangerous and progressing faster than expected. did.
J. Kevin Hiers, a fire scientist at the U.S. Geological Survey and Tall Timbers Research Station in Tallahassee, Florida, helps teach land managers how to burn open fields in an increasingly volatile landscape. To do so, he and other researchers spent several years working on a flight simulator — a video game-like training system that, as Dr. Hiers puts it, “a Minecraft-like Burn Boss experience.”
He said better fire modeling is important, but so is baking that knowledge into easy-to-use tools for combustion workers. “In a training environment, you should be able to express in a very sophisticated way what the fire should or might do long before you hit the match.”
Scientists visiting Blodgett’s Forest spent their first two days on site setting up equipment and carefully surveying the landscape before it was engulfed in flames.
Dr. Banerjee and his team of graduate students and postdoctoral researchers mapped the area using lidar, a technology that captures detailed three-dimensional images, and repeatedly flew drones. a thermal camera; a multispectral camera told me how dry my brushes were. By comparing before, during, and after images, Dr. Banerjee’s team was able to pinpoint exactly how the fires changed the forest floor.
In the evening, Dr. Banerjee’s team burned a small pile of dead wood and captured GoPro video of the flickering flames and embers that were launched into the air. The footage will help the team study how embers travel and may reveal how fires spread out of control.
In another section of the forest, Dr. Landerson and Ph.D. Audrey O’Dower. Candidates at the University of Irvine put twigs and pine needles in ziplock bags, as if collecting evidence from a crime scene. planned to burn the material in They also brought instruments to Blodgett to collect smoke samples. Odwuor said such a method could one day help assess how effectively a given fire burned the fuel it was supposed to remove.
Dr. York, who works for Blodgett most of the year, took the researchers through woodlands that hadn’t been burned in three years. Burning now helps keep the plot healthy and natural, even if all the planning, coordination, and effort wasn’t natural.
The morning of the burn was sunny and hot. The researchers donned flame-retardant shirts and helmets, and Dr. York led the group to high ground as the burn boss. As he lowered his drip torch, a thin stream of fuel dripped down, attaching a flame to the torch wick. A ray of fire sprang up from the dead brown earth. Burns have started.
Dr. York and a small experienced crew walked perpendicular to the forest slopes and used torches to draw lines of blazing flames over the hills. The landscape changed rapidly. Tall trees cast lustrous and dramatic shadows across a curtain of whitish-grey smoke. The crackling of burning bushes mingled with the low mechanical hum of drones overhead.
For a while the flame had a gentle, almost dainty quality. The plants were too wet to burn hard. But as the sun rose, fires began to rapidly blacken the mountainside. Scientists carefully observed the scene while the machine collected data.
By late afternoon, Dr. York and his team had burned about 13 acres and he sat down to catch his breath. His face was sticky with sweat and dirt. The forest was smoldering around him.
Dr. Landerson took a moment to admire the brutal raw power of fire they are studying. This is both a natural and unnatural way of protecting the land. “The older I get, the more I realize how science is like art,” he said.