Answering a burning question

A York University professor has devised a method of predicting the area burned by large-scale forest fires, which could help improve their management.

Justin Podur (left), a professor in York’s Faculty of Environmental Studies, has developed a simulation model of the growth and suppression of large fires in Ontario, based on fire and weather data from the Ontario Ministry of Natural Resources.

"Most of the area burned by forest fires in Canada is due to the few fires that escape initial attack and then spread out of control," says Podur. "Our study predicts how much such fires will burn under a range of weather and firefighting conditions."

The Ontario Ministry of Natural Resources (OMNR) defines an escaped fire as one that has not been brought under control by the morning after the initial attack. Podur, along with Professor David Martell from the University of Toronto, has modelled the growth of these escaped fires, with varying weather conditions and fire suppression resources.

"Previous models have dealt with initial attack," says Podur. "Our study looks at large fires in more detail."

Podur and Martell used historical weather scenarios from 1976-2003 to drive their simulation.

Right: Podur and Martell’s study looks at large forest fires in more detail

"Our model enabled us to test the impact of changes in weather, or climate, on the frequency and severity of large fires," Podur says.

They also modelled the allocation of resources to large fires, using realistic rules for dispatch and tactics of firefighting crews and air tankers.

"Initial attack fires are given priority for air support, but the OMNR does its best to fight large fires as well. We used their understanding and expertise in building our model," says Podur.

The large-fire growth and suppression simulation model is based on Ontario’s model of initial attack, known as LEOPARDS, with which Podur hopes to link his model. "Linkages between our model and LEOPARDS could provide us with an even better understanding of area burned, fire weather, and fire suppression," he says.

Podur notes that the Province of Ontario spends an average of $85 million annually on fire management, with large-fire management comprising a significant portion of this expense. Prevention is important in this equation, but some fires can’t be contained.

"Fire suppression makes a difference even with large fires, but if the weather is severe the area burned will be high no matter what we do."

The study, "A Simulation Model of the Growth and Suppression of Large Forest Fires in Ontario," was published in the International Journal of Wildland Fire, in July 2007.