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* Metric Name: Time Since Last Fire *  

* Tier: 2  

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

* Unit Of Measure: Years  

* Represent element and pillar: Yes  

* Type and distribution of data: Left-skewed, beta-like distribution representing percentages. Raw data values range from 0 to 113 years.  

* Translation: Where has fire occurred within the fire return interval?  

* 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 < 133% of the average fire return interval (i.e., mean FRI + (0.333 * mean FRI)). More favorable (translated to +1) set at time since last fire being no more than 33% longer than the average fire return interval, less favorable (translated to -1) set at > 67% longer than the average fire return interval. 

Figure . Histogram and scoring of time since last fire in Southern California

Figure . Histogram of translated time since last fire in Southern California

Figure . Maps displaying raw metric and translated metric time since last fire
in Southern California

  

* Metric Definition and Relevance: Time Since Last Fire (TSLF), from the Fire Return Interval Departure (FRID) map, provides information (in years) to indicate the length of time since an area last burned. The raw values of this data could not be translated to condition scores for current conditions.  

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