DFFM Wildfire Risk for Dewey-Humboldt

DFFM Wildfire Risk Arizona

Wildfire Risk

Wildfire Risk represents the possibility of loss or harm occurring from a wildfire and is displayed in the Arizona WRA by the Fire Risk Index. It is a primary output of the Arizona Wildfire Risk Assessment (Arizona WRA). Wildfire Risk combines the likelihood of a fire occurring (Threat), with those areas of most concern that are adversely impacted by fire (Fire Effects), to derive a single overall measure called the Wildfire Risk Index. It identifies areas with the greatest potential impacts from a wildfire considering the likelihood of an area burning and the impacts to values and assets aggregated together. Since all areas in Arizona have the Wildfire Risk Index calculated consistently, it allows for comparison and ordination of areas across the entire state.

Fire Threat is a measure that has been calculated which is closely related to the likelihood of an area burning. It is mapped as the Fire Threat Index in the Arizona WRA.

Fire Effects are comprised of two inputs: Values Impacted and Suppression Difficulty. The Fire Effects Index identifies those areas that have important values that could be adversely impacted by a wildfire and also might be in areas where fire suppression activities are difficult. Values Impacted in the Arizona WRA include Wildland Development Areas (WUI), Forest Assets, Riparian Assets, Drinking Water Importance Areas (watersheds) and Infrastructure Assets. Refer to the Values Impacted Rating for more information these values.

To aid in the use of Wildfire Risk for planning activities, the output values are categorized into nine (9) categories. These are given general descriptions from Lowest to Highest Risk.

DFFM Wildfire Threat for Dewey-Humboldt

DFFM Wildfire Threat for Arizona

Wildfire Threat

Wildfire Threat is a number that is closely related to the likelihood of an acre burning and is displayed in the Arizona WRA by the Fire Threat Index. The Fire Threat Index is derived from historical fire occurrence, landscape characteristics including surface fuels and canopy fuels, percentile weather derived from historical weather observations and terrain conditions. These inputs are combined using analysis techniques based on established fire science to develop resultant fire behavior.

The measure of Wildfire Threat used in the Arizona WRA is called Fire Threat Index (FTI). FTI combines the probability of an acre igniting (Fire Occurrence), the expected final fire size based on rate of spread in four weather percentile categories and the effectiveness of fire suppression resources. Since all areas in Arizona have FTI calculated consistently, it allows for comparison and ordination of areas across the entire state. For example, a high threat area in East Arizona is equivalent to a high threat area in West Arizona.

To aid in the use of Wildfire Threat for planning activities, the output values are categorized into nine (9) categories. These are given general descriptions from Lowest to Extreme Threat.

The Fire Threat map is derived at a 30 meter resolution. This scale of data was chosen to be consistent with the accuracy of the primary surface fuels dataset used in the assessment. With care, it can be used for site specific analysis as well as for regional, county or local protection mitigation or prevention planning.

DEWEY-HUMBLODT FIREWISE RECOGNIZED COMMUNITIES

Dewey-Humboldt Firewise 501(c)3

EIN: 84-3589586

P O Box 764

Humboldt AZ 86329