Improved fire severity mapping in the North American boreal forest using a hybrid composite method

Remote Sensing in Ecology and Conservation
By: , and 



Fire severity is a key driver shaping the ecological structure and function of North American boreal ecosystems, a biome dominated by large, high-intensity wildfires. Satellite-derived burn severity maps have been an important tool in these remote landscapes for both fire and resource management. The conventional methodology to produce satellite-inferred fire severity maps generally involves comparing imagery from 1 year before and 1 year after a fire, yet environmental conditions unique to the boreal have limited the accuracy of resulting products. We introduce an alternative method – the ‘hybrid composite’ – based on deriving mean severity over time on a per-pixel basis within the cloud-computing environment of Google Earth Engine. It constructs the post-fire image from satellite data composited from all valid images (i.e., clear-sky and snow-free) acquired in the time period immediately after fire through the early growing season of the following year. We compare this approach to paired-scene and composite approaches where the post-fire time period is from the growing season 1 year after fire. Validation statistics based on field-derived data for 52 fires across Alaska and Canada indicate that the hybrid composite method outperforms the other approaches. This approach presents an efficient and cost-effective means to monitor and explore trends and patterns across broad spatial domains, and could be applied to fires in other regions, especially those with frequent cloud cover or rapid vegetation recovery.

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Publication type Article
Publication Subtype Journal Article
Title Improved fire severity mapping in the North American boreal forest using a hybrid composite method
Series title Remote Sensing in Ecology and Conservation
DOI 10.1002/rse2.238
Volume 8
Issue 2
Year Published 2022
Language English
Publisher Zoological Society of London
Contributing office(s) Alaska Science Center Geography
Description 14 p.
First page 222
Last page 235
Country Canada, United States
State Alaska
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