Look for complete geospatial metadata in this layer's associated xml document available from the download link

* Metric Name: FRID Condition Class for Departure  

* Tier: 3  

* Data Vintage: 2022. Includes disturbances through the end of 2022.  

* Unit Of Measure: Categorical, departure condition  

* Represent element and pillar: No.  

* Type and distribution of data: Bimodal distribution representing categorical values. Raw data values range from -3 to 3.  

* Translation: Where is the fire return interval within +/-33% of the historical range?  

* Translation method and outcome: Raw data values translated to range from +1 to -1 representing more favorable to less favorable conditions, respectively. **** The proposition of more favorable is based on the objective of being within 33% (more or less frequent) of the average fire return interval. More favorable (translated to +1) set at –1 to +1 condition class (corresponding to -33% to 33% of the average fire return interval), and less favorable (translated to -1) set at -3 condition class for too frequent fire, and 3 for too infrequent fire. FRID itself is an interpretation of conditions that are expected to be more resilient based on historical fire regimes. 

Figure . Histogram and scoring criterion of mean condition class fire return
interval departure, across Southern California.

Figure . Histogram of translated mean condition class fire return interval
departure, across Southern California

Figure . Maps displaying raw metric and translated metric mean condition class
fire return interval departure, across Southern California

  

* Metric Definition and Relevance: This metric uses the mean percent FRID to a measure of the extent to which contemporary fires (i.e., since 1908) are burning at frequencies similar to the frequencies that occurred prior to Euro-American settlement, with the mean reference FRI binned into another basis for comparison. Mean PFRID is a metric of fire return interval departure (FRID) and measures the departure of current FRI from reference mean FRI in percent.  

* Credits: Fire History (2022), CAL FIRE; Existing Vegetation (CALVEG 2011), Region 5, MARS Team