Fire Return Interval Departure (Frid) - Current Fire Return Interval -Since 1970

The fire return interval departure (FRID) analysis quantifies the difference between current and pre-settlement fire frequencies, allowing managers to target areas at high risk of threshold-type responses owing to altered fire regimes and interactions with other factors. This is a measure of the extent to which contemporary fires (i.e. since 1970) are burning at frequencies similar to the frequencies that occurred prior to Euro-American settlement, with the mean reference FRI as the basis for comparison. With this metric, mPFRID_1970, the same formulas are used as with meanPFRID but with 1970 as the baseline rather than 1908. Important note: because 1970 is the baseline for this measure, no fires before 1970 are taken into account and all PFRs start at a PFRID of zero beginning in 1970.

Data and Resources

Additional Info

Field Value
Version Version 5.0
Last Updated March 28, 2025, 08:36 (UTC)
Created March 7, 2025, 07:53 (UTC)
categorical_values {"53": 174306030, "26": 66235929, "18": 19116343, "13": 4144285, "11": 853996, "9": 167392, "8": 53077, "5": 2900, "7": 14279, "6": 6525, "4": 9}
category /Fire Dynamics/Functional Fire/Fire Return Interval Departure (FRID)
collection_name California Landscape Metrics
creation_method Current fire return interval 1970 is calculated by dividing the number of years in the fire record by the number of fires occurring between 1970 and the current year in a given area plus one. _CurrentFRI_1970 = Number of years/Number of Fires +1_
data_units Average Years
data_vintage 2022. Includes disturbances through the end of 2022.
date_updated August 2024
element Functional Fire
encoding utf8
file_name FRI_Current_19702022_202401_T1_v5
format GeoTiff
harvest_object_id 2dd1eec9-d0b8-46e4-9162-4c537a1e865f
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 53.0
metric_definition_and_relevance The fire return interval departure (FRID) analysis quantifies the difference between current and pre-settlement fire frequencies, allowing managers to target areas at high risk of threshold-type responses owing to altered fire regimes and interactions with other factors. This is a measure of the extent to which contemporary fires (i.e. since 1970) are burning at frequencies similar to the frequencies that occurred prior to Euro-American settlement, with the mean reference FRI as the basis for comparison. With this metric, mPFRID_1970, the same formulas are used as with meanPFRID but with 1970 as the baseline rather than 1908. Important note: because 1970 is the baseline for this measure, no fires before 1970 are taken into account and all PFRs start at a PFRID of zero beginning in 1970.
minimum_value 4.0
pillar Fire Dynamics
spatial {"type": "Polygon", "coordinates": [[[-124.5090833859125, 32.4242698701859], [-113.49380570277376, 32.4242698701859], [-113.49380570277376, 42.1119747450123], [-124.5090833859125, 42.1119747450123], [-124.5090833859125, 32.4242698701859]]]}
sub_element Fire Return Interval Departure (FRID)
tier 1