FIGHTING FIRE WITHFIRE
HOW DO YOU FIGHT A FOREST FIRE? WITH FLAMES, SOMETIMES
There may be several hundred different wildfires in British Columbia — and each has unique characteristics.
A fire that’s burning in the tops of trees, for example, is basically unstoppable, said Mike Flannigan, a professor at the University of Alberta who researches fires.
A fire smouldering in the ground can burn for months, even years. A fire might just be left to burn, if it’s in an especially remote area or is in particularly difficult terrain where firefighters can’t get in and water bombers cannot fly, while others are subject to immediate, aggressive attacks to try to shut them down — especially if they’re at risk of torching towns.
The B.C. Wildfire Service is, as of Monday, fighting 550 fires across B.C.; smoke from these blazes has blanketed much of the west for the past week. Fifty-four of them are fires “of note,” the province said, meaning they warrant particular concern (might be very large) or could be threatening life or property. There are 48 evacuation alerts — be ready to leave — that affect 15,770 people, and 31 evacuation orders — leave right now — affecting 4,830 people.
Among those fires, there’s a huge variety in what can happen and how they burn. British Columbia has “a landscape that’s full of contiguous fuel,” said Robert Gray, a fire ecologist in Chilliwack, B.C., and each fire is unique, he said, because of the topography, weather and fuel. “There’s any number of potential combinations there,” said Gray.
When a fire goes through a major growth spurt, Gray said, it’s usually because of a handful of windy days. (As well, atmospheric conditions can lead to what amounts to a fire vortex, with so much energy that the fire “just goes,” Gray said.) “When it’s doing those runs, you just back off,” said Gray.
Flannigan said a fire can jump the size of a football field in about 15 minutes.
Fires can go back and forth between a wind-drive and a convection-style fire, Flannigan said, based on the available fuel and weather patterns.
“It doesn’t matter how much rain you’ve had in the spring or winter; once the snow’s gone, you give me a week of hot, dry, windy weather, I can give you a raging inferno,” Flannigan said.
Windy weather last week, for example, raised concerns that the Shovel Lake fire — the largest blaze at roughly 850 square kilometres, less than 10 kilometres from the village of Fraser Lake — was going to expand even more rapidly.
For many of the largest or most aggressive fires, the goal isn’t really to put them out: it’s to direct them or chip away at them, and keep them within a specific area, by creating guards by hand or with heavy equipment.
Another tactic for fighting huge, fast-burning fires is what’s called a back burn, basically, where a fire is lit in front of the wildfire. It then burns up all the fuel, in hopes that the big, outof-control fire dies out when it runs out of flammable material. That tactic’s been used fighting the Shovel Lake fire. Claire Allen, a fire information officer, said they’d lit six kilometres of perimeter to try to stall that fire. “Really, it is one of our primary firefighting tactics,” Allen said.
That fire can be lit by hand, or by combustible pellets dropped from a helicopter.
“When you see them in action, being used for a burn-off on a wide-scale operation, it’s pretty impressive,” Allen said.
Other tactics include retardant dropped from planes and helicopters, or water; crews dig fire breaks by hand or with machinery and try to use natural breaks, such as rivers and roads, to guide, fight and chip away at fires.
Last week, the B.C. government declared a state of emergency. More than 3,500 staff — firefighters and support staff — are working on the fires; 731 are from out of province, and more than 100 soldiers are included, too.
Fortunately, Ryan Turcot, a fire information officer, said, there’s been less lightning lately, which was one of the major factors in the spike in wildfires since the start of August.
In the best-case scenario, fires are attacked and extinguished rapidly.
But, that’s not always possible logistically. And besides, there are many ecological and practical benefits to forest fires. Practically speaking, a torched area won’t burn the next fire season, creating natural fire breaks that could last years, even decades, Flannigan said.
And so, sometimes, if there’s no real threat, provinces will just let the fires burn. “It’s just Mother Nature, cycle of life, and if anything, it may be beneficial to the forest,” Flannigan said.
GIVE ME A WEEK OF HOT, DRY, WINDY WEATHER, I CAN GIVE YOU A RAGING INFERNO.