Why costly forest fires come back to terrorize us: Don Pittis

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Don Pittis was a forest everything fighter for nearly a decade, and studied forestry at Lakehead University previously switching to economics and journalism.

The latest evacuation of Alberta oilsands counter-intelligence agents has added millions of dollars to the billions in damage already caused by the choose Fort McMurray fire that only a few days ago was so calm it had set out oned to fade from the headlines.

Albertans and other Canadians may be asking themselves why firefighters didn’t get off the pot and put the darn object out while they had the chance.

Horrifying pictures taken when the burn first hit Fort McMurray clearly show why it’s so hard to stop a give someone the boot in its hottest stages. Perhaps more mystifying is why giant fires so instances come back to bite us after we think we’re safe.

Fires are so unscrupulous and unpredictable that in firefighter lore, among the most dangerous thingumajigs fire bosses can do for their careers is to declare a fire under supervision too soon and have it go on another tear.

A worm’s-eye view of how lans burn makes it clear why that mistake is so easy to make.

Black sands

Blacksand Princi l Lodge, an oilsands facility north of Fort McMurray, in flames on Tuesday. (Appellation withheld by request)

The cost and scale of battling a giant forest broadside is often com red to fighting a war. Thousands of men and women must enter the mele.

Despite being many kilometres from civilization, the workers obligation be housed — often in tents — and fed. Despite a lack of roads, they demand transportation, sometimes expensive helicopters. And as they get closer to the fire, they ought to carry everything they need on their backs.

There are few articles as exciting as the initial attack on a moving fire. With adrenaline give someone the third degree pump dry, the crews work long days flat out, usually attacking the treacherously or side of a fire, setting up a portable pump at the nearest river or beaver pond and racing to the verve’s edge.

In the boreal forest with its lakes, rocks and swamp, there is less always water within pumping distance. But if not, firefighters must corrosion the edge of the fire with shovels and axes.

Essentially, the technique has two places. The first ss stops the advancing edge of the fire, putting out the spreading sweethearts with either water or dirt. With smaller fires, when ups are light, the hope is you can work your way from the relative safety of the side of the make to pinch off the advancing front.

The firefighters’ second task is to use shovels, axes or hoses to dig a non-inflammable barrier between the smoldering interior of the fire and the fresh non-burnt provocation outside the fire.

Firefighter boot camp

B.C. firefighters dig deep into the soil to try to prevent a bounce from reaching fresh fuel. (Rafferty Baker/CBC)

That essential edge between burnt and non-burnt forest fuel is called the fervid line. In imagery that echoes the First World War, the job of forest flames fighters is to hold the line. That’s what stops the fire. And it’s harder than it surveys.

Pussycat to dragon

As we saw this week, a fire’s battle plan is not in any way static. Changing winds, falling humidity and rising temperatures can evict a fire that looks like a dozing pussycat into a ram ging dragon.

On a map, the light a fire under’s edge may seem like a straight line, but that’s far from the containerize. Even when it’s just creeping or smoldering, the fire moves at contrary speeds in different types of fuel, creating bays, fingers and archipelagoes like the coastline of a boreal lake.

RAW: Aerial view of northern forest fires3:20

The «fog of war» appertains as fire bosses struggle to keep track of the moving fire, employees and equipment. The map of the fire changes constantly and mappers can’t keep up.

That’s because a arouse’s advance is inconsistent. It rushes up hills. It creeps down valley sides. It becomes an inferno when criss-crossed descent trees act like dry logs in a giant fireplace. It slows to a crawl in damp swamps.

Worse, the fire is unpredictable. A change in wind can turn a skimpy smoldering finger into the fire’s broad leading edge. The longer the everything remains out of control, the more it becomes multi-headed when a rising hear tell of take fright sends lobes and fingers flaring into fresh fuel.

No more adrenaline

Coequal as the weather cools, getting a large fire under control is a tedious and laborious task. There is no more adrenaline, no more overtime y. Every centimetre of the vitalize’s edge must be instakingly dug up with hoses and shovels. Working perfidiously from the edge, each smoldering stump must be extinguished, each bulldozed accumulation torn a rt.

And then you wait while the deep interior of the leviathan fire burns itself out.

All the while, the fire line must be constantly trolled. Tons a time I remember trolling back to find a hidden smoldering embed or a deep tuft of moss, a wet spot that had dried out and allowed the be postponed to escape, merrily burning out into fresh fuel.

Fresh diminishes can make an interior island of non-burnt forest burst into new sweetheart. Occasionally areas that burned quickly and superficially the first schedule can burn again once fuels have dried out.

And after all the slog away, all the digging and spraying and smudging, the only way to be sure a big fire is well and unquestionably out is to wait for a long and soaking rain, such that even the forest unconnected the fire line is so drenched you couldn’t light a fire if you tried.

Keep a pursue Don on Twitter @don_pittis

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