Hazard Assessment

The hazard in wildland fire is composed of the following:

Fire Behavior

Evaluate the current and expected fire behavior and rank the element Low, Moderate or High. Considerations include intensity, rates of spread, crowning; and profuse or long-range spotting.

The following guidelines can help you determine an appropriate selection for Fire Behavior:

Table 1: Determining Selection Values for Fire Behavior

Low

Moderate

High

  • Short duration flaming front with occasional torching.
  • Fuels are uniform and fire behavior can be easily predicted and tactics implemented.
  • Short range spotting occurring.
  • Moderate rates of spread are expected with mainly surface fire and torching.
  • Fuels and terrain are varied, but don’t pose significant problems in holding actions.
  • Long range spotting > mile.
  • Extreme rates of spread, and crown fire activity are possible.
  • Fuels, elevation, and topography vary throughout the fire area, creating high resistance to control.

Fuel Condition

Consider fuel conditions where fire is currently burning and where it will be burning and rank this element Low, Moderate or High. Evaluate fuel conditions that exhibit high ROS and intensity for your area, such as those caused by invasive species or insect/disease outbreaks; and/or continuity of fuels. 4047

The following guidelines can help you determine an appropriate selection for the Fuel Condition:

Table 1: Determining Selection Values for Fuel Condition

Low

Moderate

High

  • Fuel loading is low.
  • Large-scale fuel treatments have reduced continuous fuels.
  • No evidence of insect/disease outbreaks.
  • Changes resulting from insect and disease outbreaks are minimal.
  • Few if any fire return intervals have been missed and fuel complexes are similar to historic levels.
  • Invasive species do not contribute to increased fire spread or intensity.
  • Fuel load is moderate and supports active fire spread.
  • Past fuels treatments may no longer be effective, or recent treatments have temporarily increased dead fuel loading.
  • Evidence of insect/disease outbreaks (red needles, dead standing timber, etc.).
  • Some fire return intervals have been missed, fuel complexes have been altered and present potential for fires with severity and intensity levels in excess of historic levels.
  • Invasive species contribute to fire spread.
  • Fuels are continuous on the landscape and will readily support continued fire growth.
  • No fuels treatments have occurred.
  • Moderate to extensive insect/disease outbreaks and large stands of dead standing timber.
  • Significant vegetative changes from the historic situation have occurred.
  • The highly altered composition and structure of the vegetation predisposes the landscape to fire effects well outside the historic range of variability.
  • Invasive species greatly contribute to uncharacteristic fire spread and intensity.

Potential Fire Growth

Evaluate the potential fire growth, and rank this element Low, Moderate, or High. Considerations would include current and expected fire growth based on fire behavior analysis and the weather forecast and/or the ability to control the fire.

The following guidelines can help you determine an appropriate selection for Potential Fire Growth:

Table 1: Determining Selection Values for Potential Fire Growth

Small

Medium

Large

  • Little fire growth is expected.
  • Weather conditions (current and forecasted) are such that fire growth will be low.
  • Resistance to control, if implemented, for dominant fuel type is low.
  • Fire behavior leads to moderate fire growth.
  • Weather conditions are not forecasted to worsen.
  • Dominant fuel type is burning readily but is predictable and characteristic of the time of year and conditions.
  • Control efforts implemented are typically successful and resistance to control for dominant fuel type is moderate.
  • Fire growth is well beyond what is typical for the dominant fuel type.
  • Extreme fire behavior (torching, crowning, long range spotting, etc.) is occurring or predicted.
  • Weather conditions are predicted to worsen (hotter, drier, windier).
  • Dominant fuel type is burning more readily than usual and exhibiting greater than typical fire growth.
  • Resistance to control is high. Control efforts to date have been unsuccessful due to high rates of spread and rapid fire growth.