Heavy snowfall no guarantee against forest fires
Mike W. Bryant
Northern News Services
Yellowknife (May 18/01) - The memories of 1998's devastating forest fire along the Ingraham Trail still rings fresh in many cabin owner's minds.
Even with the heavy snowfall experienced last winter forestry managers are reluctant to make any predictions for this summer's fire season.
According to Lance Schmidt, manager of forests for the North Slave region, Department of Resources, Wildlife and Economic Development (RWED), predicting the intensity of this year's fire season is simply too tough to call.
"We had about 120 to 140 per cent over normal precipitation over the winter, but that doesn't mean anything," Schmidt said.
"What happens with the snow is that a lot of it is lost through evaporation and sublimation."
As the days grow longer, the snow melts faster Schmidt explained. By the time summer hits, there might not be enough moisture left in the soil to significantly diminish the amount of forest fire outbreaks.
"Especially in the rock country," Schmidt said. "You have almost no soil depth and the snow runs off into the lakes."
Compared to some areas down south, like the flatlands of Alberta which has deep duff layers of between four to six inches, the duff layer north of Great Slave Lake is relatively thin, mere millimetres in depth.
Duff is the primary layer of soil on the forest floor. Mainly composed of decaying plant matter and other detritus, it helps to contain moisture in the soil. If the soil becomes parched, the potential for forest fires is increased.
"The best I think snow can do is slow it down (the time it takes for the forest fire season to begin)," Schmidt said.
"What is more important is rain, and if we were to get a couple days of rain a week throughout the summer, then we won't have much of a fire season."
Forest fire potential is calculated into a formula known as the drought code. It takes into account the amount of available fuel, such as trees and fallen logs, and the moisture contained within them. Drought codes begin at a value of zero and can go upwards of 1,000.
According to Schmidt, it's when drought code values rise above 400 that forestry managers become concerned.
The projected drought code this spring stands at approximately 130. The spring drought code in 1998, the year the Tibbitt Lake fire burned 165,000 hectares of forest, including several cabins on the Ingraham Trail, was even lower.
"I think a lot of the Ingraham Trail area, say around Harding Lake, is due for a fire," Schmidt said.
"Due to the natural fire regime, dead wood and accumulation of fine fuels - leaves, branches, moss - it keeps building up every year."
