Skip to main content
U.S. flag

An official website of the United States government

This site is currently in beta, and your feedback is helping shape its ongoing development.

Return to search results

Terrestrial Condition Assessment (TCA) Alaska Uncharacteristic Fire Severity Moderate (Image Service)

Published by U.S. Forest Service | Department of Agriculture | Metadata Last Checked: January 27, 2026 | Last Modified: 2025-09-23
Direct Download (Raster Data Gateway) Objective: The TCA Uncharacteristic Disturbance Indicator identifies locations that have had recent catastrophic disturbance including uncharacteristically severe wildfires resulting in needs for reforestation, revegetation or other restoration work.Data: The LANDFIRE Historical Percent of Mixed Severity raster dataset for Alaska (AK_120_PMS) was combined with the Monitoring Trends in Burn Severity (MTBS) data (1984-most recent) and Composite Burn Index (Parks et al. 2018) data for the year prior to the assessment year derived from NIFC Fire Perimeters (>1000 ac) to identify areas that have experienced unnaturally severe wildfires in the recent past, since 1984. There is a 2-year lag between the most recent MTBS data and the TCA Assessment year (i.e. in the 2024 TCA Assessment, available MTBS data were from 1984-2022). To reduce this lag to 1 year, we compute the Composite Burn Index (CBI) for the year prior to the current assessment year using fire perimeters from National Interagency Fire Center (NIFC) with methods adapted from Parks et al. 2019. The CBI methods were added for the 2021 assessment. The “Moderate severity” metric (layer) represents areas mapped with a dominant condition of mixed severity fire (based on PMS) but had a high severity MTBS fire in that location. Data Format: Raster data are binary: (1) “unnaturally severe fire” or (0) otherSpatial Resolution: 30mSource data: MTBS fire severity, expected fire severity , CBI methods, National Interagency Fire Center Perimeters (for CBI)Additional Resources:Details on Method Changes and Source Data VersionsOverview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour PresentationExplore the results of the most recent assessment: TCA Interactive Data ViewerLearn more about the TCA KPI: TCA Dashboard*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request

data.gov

An official website of the GSA's Technology Transformation Services

Looking for U.S. government information and services?
Visit USA.gov