A 20 m spatial resolution peatland extent map of Alaska

Area of Science:

• * Ecosystem mapping and remote sensing.
• * Geospatial analysis of terrestrial environments.

Background:

• * Peatlands are widespread in northern regions but existing remote sensing products have limited spatial resolution (1 km²).
• * This resolution often fails to capture sub-pixel heterogeneity and introduces uncertainties in peatland distribution mapping.
• * Accurate mapping is crucial for understanding peatland carbon, nutrient, and fire dynamics.

Purpose of the Study:

• * To develop a high-resolution (20 m) peatland map for Alaska.
• * To improve the accuracy of regional peatland distribution data.
• * To provide a foundational dataset for ecological studies in Alaska.

Main Methods:

• * Utilized a fusion of Sentinel-1 radar, Sentinel-2 multispectral imagery, and ArcticDEM data.
• * Employed machine learning classifiers trained with peat cores and ground observations.
• * Spatially constrained the mapping using a peatland suitability model.

Main Results:

• * Generated a ~1.5 million km² peatland map of Alaska at 20 m resolution.
• * Achieved an overall agreement of 85% for statewide peatland mapping.
• * Identified peatlands covering 7.3% of Alaska's total terrestrial area, with variations across ecoregions.

Conclusions:

• * The new high-resolution peatland map significantly enhances our understanding of peatland distribution in Alaska.
• * This dataset will improve ecological models of carbon, nutrient, and fire processes.
• * The findings underscore the importance of high-resolution mapping for characterizing heterogeneous landscapes.