Media Guide to Forest Fires - Glossary of Wildfire Terms

Air tanker — A fixed-wing aircraft fitted with tanks and equipment for dropping suppressants or retardants on wildfires.

Campaign Fire — A wildfire of such size, complexity and/or priority that its extinction requires a large organization, high resource commitment, significant expenditure, and prolonged suppression activity. (Synonym: Project Fire.)

Control a Fire — To complete a control line around a fire, any spot fires therefrom, and any interior island(s) to be saved; cooling down all hot spots that are immediate threats to the control line until the lines can be expected to hold under foreseeable conditions. (Stages of Control: see fire status.)

Control Line — A comprehensive term for all constructed or natural fire barriers and treated fire perimeter used to control a fire. (See Fireguard and Fireline.)

Fine Fuels — Fuels that ignite readily and are consumed rapidly by fire (e.g., cured grass, fallen leaves, needles, small twigs). Dead fine fuels also dry very quickly. (Synonym: Flash Fuels. Note Medium Fuels and Heavy Fuels.)

Fire Ban — A Ministerial Order issued by the provincial government to restrict the use of fire in areas of high hazard. The order describes what types of fires are allowed or may in fact entirely prohibit the use of any fire.

Fire Behaviour — 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.

Some common terms used to describe fire behaviour include the following:

  • Smouldering: A fire burning without flame and barely spreading.

  • Creeping: A fire spreading slowly over the ground, generally with a low flame.

  • Running: A fire rapidly spreading and with a well-defined head.

  • Torch or Torching: A single tree or a small clump of trees is said to "torch" when its foliage ignites and f ares up, usually from bottom to top. (Synonym - Candle or Candling.)

  • Spotting: A fire producing firebrands carried by the surface wind, a fire whirl, and/or convection column that fall beyond the main fire area.

  • Crowning: A fire ascending into the crowns of trees and spreading from crown to crown. (Note the three classes of Crown Fire under Wildfire.)

Fire Danger — A general term used to express an assessment of both fixed and variable factors of the fire environment that determine the ease of ignition, rate of spread, difficulty of control, and fire impact. (Note Fire Hazard, Fire Risk, and Burning Conditions.)

Fireguard — A strategically planned barrier, either manually or mechanically constructed, intended to stop or retard the rate of spread of a fire, and from which suppression action is carried out to control a fire. The constructed portion of a control line.

Fire Hand Tools — The principle hand tools used in wildf re suppression are:

  • Pulaski: A combination chopping and trenching tool, which combines a single-bitted axe-blade with a narrow adze-like trenching blade fitted to a straight handle. Useful for grubbing or trenching in duff and matted roots. Well-balanced for chopping.

  • Pump: An engine driven pump, usually gasoline powered, specifically designed for use in fire.

  • Shovel: A type of shovel specifically designed for use in constructing a fire line, having a tempered blade with both edges sharpened. Used for digging, scraping, grubbing and cutting.

  • Backtank: A plastic or metal container that holds water carried on the back of a firefighter. Water is sprayed out manually.

Fire Status:

  • Out-of-Control: A wildfire not responding or only responding on a limited basis to suppression action such that perimeter spread is not being contained. (Synonym: Not under Control)

  • Being Held (BH): Indicates that with currently committed resources, sufficient suppression action has been taken that the wildfire is not likely to spread beyond existent or predetermined boundaries under prevailing and forecasting conditions. (Synonym: Partial Control, Contained)

  • Under Control (UC): A wildfire having received sufficient suppression action to ensure no further spread of the fire.

  • Being Patrolled: In a state of mop-up: the wildfire area is being walked over and checked for hot spots.

  • Extinguished: Having been extinguished. (Synonym: Out)

Fire Suppression Tactics — Determine exactly where to establish control lines, what to do along these lines, and how best to use each firefighting resource group to cope with site-specific conditions and fire behaviour at the moment. This is a line function.

Hot Spot — Defined as follows:

  1. A particularly active part of a wildfire.
  2. A small area of smouldering or glowing combustion, which maybe exhibiting smoke, located on or within the wildf re perimeter; a term commonly used during the mop-up stage of a f re. (Synonym: Smudge.)

Incident Management Team — The Incident Commander and all incident operations at the incident site.

  • Incident Commander: The individual responsible for the management of all incident operations at the incident site.

  • Information Officer: A member of the Command Staff responsible for interfacing with the public and media or with other agencies requiring information directly from the incident. There is only one information officer per incident. The information officer may have assistants.

Initial Attack — The action taken to halt the spread or potential spread of a wildfire by the first firefighting force to arrive at the wildfire.

Infrared Scanner — An optical-electronic system for identifying or obtaining imagery of thermal infrared radiation to detect non-smoking wildfires or wildfire parameters through smoke. May also be used for mapping. The systems may be operated from an air craft or hand held unit.

Initial Attack Crew — Personnel trained, equipped and deployed to conduct suppression action to halt the spread or potential spread of a wildfire with in the first burning period. (Before 10:00 a.m. the next day).

Sustained Action Crew — Personnel trained, equipped and deployed to conduct suppression action on a wildfire for an extended period of time.

Rate of Spread (ROS) — The speed at which a wildfire extends its horizontal dimensions, expressed in terms of distance per unit of time. Generally thought of in terms of a wildfire's forward movement or head fire rate of spread, but also applicable to backfire and flank fire rate of spread.

Slash — Debris left as a result of forest and other vegetation being altered by forestry practices and other land use activities (e.g., timber harvesting thinning and pruning, road construction). Includes material such as logs, splinters or chips, tree branches and tops, uprooted stumps and broken or uprooted trees and shrubs.

Snag — A standing dead tree or part of a dead tree from which at least the smaller branches have fallen. (Synonym: chicot.)

Values at Risk — The specific or collective set of natural resources and human-made improvements/developments that have measurable or intrinsic worth and that could or may be destroyed or otherwise altered by wildfire in any given area (e.g., structures, logging, etc.)

Woods Closure — An area in which specified activities or entry are temporarily restricted by agency legislation to reduce risk of human-caused fire. An official order by a designated authority to close a specified forest area.

Forest Fire — Any wildfire that is burning in forested areas, grass or barren. (See Spot Fire.)
The main types of forest fire are:

  • Ground Fire: A fire that burns in the ground fuel layer. (Synonym: Subsurface Fire.)

  • Surface Fire: A fire that burns in the surface fuel layer, excluding the crowns of trees, as either a head fire, flank fire, or backfire.

  • Crown Fire: A fire that advances through the crown fuel layer, usually in conjunction with a surface fire. Crown fires can be classified according to the degree of dependence on the surface fire phase, as follows:

    1. Intermittent: A fire in which trees discontinuously torch, but rate of spread is controlled by the surface fire phase. (Synonym: Passive CrownFire.)

    2. Active Crown Fire: A fire that advances with a well-defined wall of flame extending from the ground surface to above the crown fuel layer. Probably most crown fires are of this class. Development of an active crown fire requires a substantial surface fire, and thereafter the surface and crown phases spread as a linked unit. (Synonym: Dependent Crown Fire.)

    3. Independent Crown Fire: A fire that advances in the crown fuel layer only. (Synonym: Running Crown