Linking repeat lidar with Landsat products for large scale quantification of fire-induced permafrost thaw settlement in interior Alaska

• Published in: Environmental Research Letters
• Main Authors: Zhang, Caiyun, Douglas, Thomas A, Brodylo, David, Jorgenson, M Torre
• Other Authors: the U.S. Department of Energy, Office of Science, U.S. Department of Defense, U.S. Army Corps of Engineers Engineer Research and Development Center
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2023
• Subjects: Ice; permafrost; Alaska
• Online Access: http://dx.doi.org/10.1088/1748-9326/acabd6; https://iopscience.iop.org/article/10.1088/1748-9326/acabd6; https://iopscience.iop.org/article/10.1088/1748-9326/acabd6/pdf

Abstract The permafrost–fire–climate system has been a hotspot in research for decades under a warming climate scenario. Surface vegetation plays a dominant role in protecting permafrost from summer warmth, thus, any alteration of vegetation structure, particularly following severe wildfires, can cause dramatic top–down thaw. A challenge in understanding this is to quantify fire-induced thaw settlement at large scales (>1000 km 2 ). In this study, we explored the potential of using Landsat products for a large-scale estimation of fire-induced thaw settlement across a well-studied area representative of ice-rich lowland permafrost in interior Alaska. Six large fires have affected ∼1250 km 2 of the area since 2000. We first identified the linkage of fires, burn severity, and land cover response, and then developed an object-based machine learning ensemble approach to estimate fire-induced thaw settlement by relating airborne repeat lidar data to Landsat products. The model delineated thaw settlement patterns across the six fire scars and explained ∼65% of the variance in lidar-detected elevation change. Our results indicate a combined application of airborne repeat lidar and Landsat products is a valuable tool for large scale quantification of fire-induced thaw settlement.