Glossary of fire terminology
Burnout: is a technique used to complete a fireguard; forest fuels are burned out between a control line (e.g. road, ridge, river, fireline, or other existing breaks) and the fire's edge. This strengthens the fireguard and increases the safety of fire crews that may have to actively defend the fireguard.
Containment Area: is an area bounded by natural terrain features and forest fuel conditions that serve as fireguards, and within which a fire would pose relatively low risk to human life, property and other values. These properties allow a fire to be managed with minimal direct fire control resources and associated fire crew safety risks and costs. To provide a wide margin of safety, the containment area for a prescribed burn is much larger than the area expected to burn.
Crowning: a fire that spreads through the canopy of a forest, usually rapid.
Extreme fire behaviour: a level of fire behaviour that often precludes any fire suppression action. It usually involves one or more of the following characteristics: high rate of spread and frontal fire intensity, crowning, prolific spotting, presence of large fire whirls, and a well-established convection column. Fires exhibiting such phenomena often behave in an erratic, and sometimes dangerous, manner.
Forest Fuels: are categorized based on size and each has an index that helps determine the overall fire hazard rating.
Fine fuels: ignite readily and cause rapid fire spread (dry grass, dead leaves and tree needles, twigs and small trees).
Heavy fuels: large diameter woody or deep organic materials (logs, stumps, branch wood and deep duff) that are difficult to ignite, spread slower and burn longer.
Fire Behaviour: is the manner in which fuel ignites, flame develops and fire spreads and exhibits other related phenomena as determined by the interaction of fuels, weather, and topography.
Fireline: is used to separate the fire from forest fuels. It's dug down to mineral soils below the duff layer (about 15 cm) where a fire could smoulder and is cleared of forest fuels to a width that prevents the fire from spotting across and igniting fuels on the opposite side.
Fire Situation Analysis: an analysis of a fire and recommended management actions completed each time there is a significant change in any factor related to the fire.
Guiding principles for a Parks Canada Fire Analysis Process:
- Firefighter and public health/safety is the first priority in every fire management activity
- The role of wildland fire as a process integral to ecosystems will be incorporated into all fire management activities.
- Scientifically based risk management is the foundation of all fire management activities.
- Fire management activities will be based upon values to be protected, costs and park management objectives.
- Fire management activities require federal, First Nations, provincial / territorial and local interagency cooperation / coordination.
Ground fire: a fire that burns in the ground fuel layer.
Hectare (ha): one hectare (ha) = 100 m by 100 m area / 100 ha = one square kilometer
Humidity: the amount of water vapour or moisture in the air. Fire behaviour is dependent upon, and can be predicted from relative humidity.
Smouldering fire: a fire burning without flame and barely spreading.
Spotting: when sparks or flaming material from a fire are carried by surface wind or winds generated by the fire that fall beyond the main fire perimeter and result in spot fires.
Surface fire: a fire that burns in the surface fuel layer, excluding the crowns of the trees.
Torching: a single tree or a small clump of trees is said to "torch" when its foliage ignites and flares up.
Weather: is one of the most important factors affecting fire behaviour; its most important components are wind, temperature and humidity.