WASHINGTON, D.C. — The lengthening wildfire season in the U.S. is straining resources and people.
"It's a glorified camping trip that's costing way too much money, and I just want to go home," said California resident Leslie Rogers.
About 4.5 million homes in the U.S. are considered at high or extreme risk for wildfire damage.
Since the start of the year, there have been more than 40,474 wildfires compared to about 35,000 by this time last year, according to the National Interagency Fire Center. Approximately 4 million acres have burned so far this year, compared to 2.4 million by this time last year. In the West, 98.5 percent of all the land in the Western U.S. is experiencing a moderate or severe drought.
Now, researchers are starting to look into what may be one of the most destructive--but poorly understood--parts of a wildfire.
“Think of a charcoal glowing in your charcoal pit, but flying through the air, where it can now start other fires,” said Prof. Peter Sunderland, with the Department of Fire Protection Engineering at the University of Maryland. “This is a problem that's increasing exponentially.”
They’re called firebrands, and they are the focus of new wildfire research.
“All the rage now in wildland fire research is these firebrands. We finally understand how fire spreads from tree-to-tree, grasses-spread, kind of along in the nice line. And that's well understood,” Prof. Sunderland said. “Firebrands are changing the whole game.”
Different from embers, firebrands are about the size of a quarter. They reach temperatures of more than 1700 degrees Fahrenheit and “jump” miles ahead of a wildfire, starting new ones. However, little else is known about them.
“We're realizing now how important these are for fire spread,” Prof. Sunderland said.
At the University of Maryland lab, researchers created firebrands inside a wind tunnel and observed them.
“Firebrands tend to accumulate in one place,” he said. “And this is when you start to get trouble.”
As firebrands get increasing amounts of attention from researchers, they’re also looking for solutions, particularly, what can best protect homes and businesses in vulnerable wildfire areas.
“Once the deck catches fire, usually the whole house will be burned,” Prof. Sunderland said.
That is why they are also looking at how firebrands interact with particular materials, like wood, wood composite, and even plastic composites, to see if building codes might need to be changed to better resist firebrands.
“That's really the objective of the business, is to get into the fire codes, the communities that adopt these codes,” Prof. Sunderland said, “and that makes the wildland interface a safer place for everybody.”