Presenter: Melanie Wheatley (University of Toronto)

Major Professor: Mike Wotton

Forest fire management agencies engage in fire suppression operations to mitigate the potential disastrous impacts from forest fires to communities and values. The goal of fire suppression is to reduce fireline intensity, limit fire growth, and extinguish the fire using resources from FireRanger crews with pump and hose, to aerial suppression, including helicopters and fixed wing aircraft that can drop large amounts of water. Deciding on the right resources to send to a fire is challenging as fire managers must consider the expected fire behaviour and requirements for fire containment and extinguishment, along with future demands for limited suppression resources throughout the day. Currently, much of this decision making is based on decades-old heuristics as well as individual fire manager’s experience. The goal of this current research was to provide evidence-based information that would assist fire managers in assessing fire suppression effectiveness across a range of spatial and temporal scales, ranging from the flame to landscape scale, and from minutes to full fire seasons. Extensive datasets of fire behaviour, fire weather, fire suppression activity, and infrared (IR) detection of fire radiative power were used to study the effectiveness of water applied to spreading fire at various scales. Replicated field-based experimental burning monitored by IR imaging technology characterized the effect of water delivered at ground level on combustion zone energy change and the duration of its effect at the flame scale. At the fireline scale, I used 14 years of suppression outcomes from Air Attack Officers in Ontario to characterize the impact of water drops from airtankers on spreading fires, and I showed that the current fire intensity and resource effectiveness heuristics used across Canada are in need of modification. At the landscape scale, I characterized the factors considered by fire managers in dispatching airtankers to support FireRanger crews on the ground and developed models which assessed the probability of suppression success on those fires that receive airtanker support. The outcomes of this thesis provide an evidence-based foundation for understanding suppression effectiveness in the boreal forest which will enhance fire manager’s ability to make informed decisions regarding fire suppression resource use and allocation.

(The presentation will not be recorded but the Alaska Fire Science Consortium hopes to organize a webinar soon.)