Wildland Fire S-190/S-130 Questions And Answers

Fire Perimiter - ANS outer edge or boundary of fire Point of Origin - ANS location where competent ignition source came into contact with the material, first ignite, sustained combustion occured. Head - ANS most rapidly spreading portion of a fire's perimeter, usually to leeward or upslope. Flanks - ANS parts of a fire's perimeter that are roughly parallel to the main direction of the spread. Rear or Heel - ANS that portion of a fire edge opposite the head. Slowest spreading portion of a fire edge. Finger - ANS the long narrow extensions of a fire projecting from the main body. Pocket - ANS unburned indentations in the fire edge formed by fingers or slow burning areas. Island - ANS an unburned area within a fire perimeter. Spot - ANS fire ignited outside the perimeter of the main fire by a firebrand. Anchor Point - ANS an advantageous location, usually a barrier to fire spread, from which to start constructing a fire line. The anchor point is used to minimize the chance of being flanked by the fire while the line is being constructed. Control Line - ANS an inclusive term for all constructed or natural barriers and treated fire edges used to contain a fire. Fireline - ANS the part of a containment or control line that is scraped or dug to mineral soil. Mop up - ANS extinguishing or removing burning material near control lines, felling snags, an trenching logs to prevent rolling after an area has burned, to make fire safe, or to reduce residual smoke. Contained - ANS 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. Controlled - ANS 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 control lines. Cool down all hotspots that are immediate threats to the control line, until the lines can reasonably be expected to hold under the foreseeable conditins. Crowning - ANS Fire that advances from top to top of trees or shrubs (independent of a surface fire). Fire Triangle - ANS Oxygen, heat, and fuel. What is the material that is burning? - ANS Fuel (combustible material); especially petroleum-based products, and wild land fuels. Conduction - ANS Think of conduction as a spoon in a hot drink. Heat is conducted from one fuel particle to another to another in the same way, through direct contact. Since wood is a poor conductor (meaning heat will not travel through it easily), this process is less of a factor to fire behavior. Convection - ANS This occurs when lighter warm air moves upward. Think of convection as a smoke column above the fire. The hot gases and embers which compose the smoke column move and can dry and ignite other fuels. Radiation - ANS Radiant heat warms you as you stand close to a campfire or stand in the sunlight. Radiant heat can dry surrounding fuels and sometimes ignite them. Methods of heat transfer - ANS conduction, convection, radiation The transfer of heat through direct contact. The transfer of heat by the movement of a gas or liquid. Transfer of heat in a straight line through a gas or vacuum other than by heating of the intervening space. Wildland fuels are grouped into six fuel types - ANS 1. Grass 2. Shrub 3. Grass-Shrub 4. Timber Litter 5. Timber-Understory 6. Slash-Blowdown Size and shape classifications of fuels - ANS 0-1/4" diameter 1/4"-1" diameter 1"-3" diameter 3"-8" diameter Time lag rate classifications - ANS Fuels 0-1/4" in diameter = 1 hour Fuels 1/4"-1" in diameter = 10 hours Fuels 1"-3" in diameter = 100 hours Fuels 3"-8" in diameter = 1000 hours Fuel arrangement is divided into two primary categories - ANS Horizontal Continuity Vertical Arrangement Fuel Characteristics - ANS Fuel loading Chemical content Fuel arrangement Moisture content Size and shape Dry Bulb Temperature - ANS The temperature of the air measured in the shade, 4 to 8 feet above the ground. Wet Bulb Temperature - ANS The lowest temperature to which air can be cooled by evaporating water. Dew Point Temperature: - ANS The temperature to which air must be cooled to reach saturation. One of the most reliable methods for measuring atmospheric moisture. Relative Humidity (RH) - ANS The ratio of the amount of moisture in the air to the maximum amount of moisture that air would contain if it were saturated. Temperature and Relative Humidity: - ANS Temperature and relative humidity have an inverse relationship; when one goes up, the other goes down. Belt Weather Kit - ANS A Belt Weather Kit is a belt-mounted case with pockets fitted for anemometer, compass, sling psychrometer, slide rule, water bottle, pencils, and book of weather report forms. The Belt Weather Kit is one of the most common methods of obtaining weather observations in the field.• Use of a Belt Weather Kit is often referred to as slinging or spinning weather, due to the use of the sling psychrometer. Belt Weather Kits are used to take weather observations to provide on-site conditions to the fire weather forecaster or Fire Behavior Analyst (FBAN). - ANS Observations include air temperature, wind speed and direction, and relative humidity.