Wildland Fire Behavior S-190
Rear of fire
1. Portion spreading directly into the wind or down slope. 2. Portion opposite the head. 3. Slowest spreading portion of a fire edge, also called the heel.
1 acre
10 square chains
Crown fire
A fire that advances from top to top of trees or shrubs more or less independent of a surface fire. Types: running or dependent.
Creeping fire
Fire burning with a low flame and spreading slowly.
Spot fire
Fire ignited outside the perimeter of the main fire by a firebrand.
Torching
The burning of the foliage of a single tree or a small group of trees, from the bottom up.
Controlled
The completion of control line around a fire, any spot fires, and any interior islands to be saved. Burn out any unburned area adjacent to the fire side of the control lines. Cool down all hot spots that are immediate threats to the control line, until the lines can reasonably be expected to hold under the foreseeable conditions.
Fire perimeter
The entire outer edge or boundary of a fire
Flaming front
The zone of a moving fire where the combustion is primarily flaming. Light fuels have a shallow one, whereas heavy fuels have a deeper one.
Pockets of a fire
Unburned indentations in the fire edge formed by fingers or slow burning areas. Green or black
Chain
66 feet
Section
80 squared chains (80x80)
Smoldering
Fire burning without flame and barely spreading.
Control line
An inclusive term for all constructed or natural barriers and treated fire edges used to contain a fire.
Anchor point
An advantageous location, usually a barrier to fire spread, from which to start constructing a fireline. The anchor point is used to minimize the chance of being flanked by the fire while the line is being constructed.
Flare up
Any sudden acceleration in the ate of spread or intensification of the fire. Relatively short duration, does not change existing control plans.
Island/pocket/stringers
Area of unburned fuel inside the fire perimeter.
Spotting
Behavior of a fire producing sparks or embers that are carried by the wind and which start new fires beyond the zone of direct ignition by the main fire.
Running Fire
Behavior of a fire spreading rapidly with a well defined head.
Mop-up
Extinguishing or removing burning material near control lines, felling snags, and trenching logs to prevent rolling after an area has burned, to make a fire safe, or to reduce residual smoke.
Firewhirl
Spinning vortex column of ascending hot air and gases rising from a fire and carrying aloft smoke, debris, and flame. From 1' to 500' in diameter and can have the intensity of a small tornado.
Backing fire
That portion of the fire with slower rates of fire spread and lower intensity, normally moving into the wind and/or down slope. Heel fire
Fingers of a fire
The long narrow extensions of a fire projecting from the main body.
Fireline
The part of a containment or control line that is scraped or dug to mineral soil.
Flank of fire
The part of a fire's perimeter that is roughly parallel to the main direction of spread.
Head of fire
The part of a fire's perimeter that is roughly parallel to the main direction of spread.
Point of origin
The precise location where a competent ignition source came into contact with the material first ignited and sustained combustion occurred.
Contained
The status of a wildfire suppression action signifying that a control line has been completed around the fire, and any associated spot fires, which can reasonably be expected to stop the fire's spread.
80 chains
equals 1 mile/5280'
