Remote sensing of coastal erosion and thaw slump activities effected by heavy precipitation in West Alaska

• Main Author: Schäffler, Simon
• Format: Thesis
• Language: unknown
• Published: 2022
• Subjects: Arctic; Baldwin; Climate change; permafrost; Alaska
• Online Access: https://epic.awi.de/id/eprint/55775/; https://epic.awi.de/id/eprint/55775/1/Schaeffler_Bachelorarbeit.pdf; https://hdl.handle.net/10013/epic.7f3888b2-5854-45d3-8e4e-cd48525ade27; https://hdl.handle.net/

In this study the dynamics of retrogressive thaw slumps (RTS), which are main permafrost thawing features along the eroding coasts of the Arctic region, were investigated by using MACS airborne stereo ortho imagery of the 2021 Perma-X flight campaign in West Alaska. The attempt was a remote sensing change detection done by using digital terrain models for structure from motion photogrammetry. The developed workflow was applied at two study sites at the coast of the Baldwin Peninsula. At the time of the data acquisition in June and July 2021 the area was facing heavy rainfalls, which are assumed to occur more often and intensely due to climate change. The aim was to use the results of the digital terrain model differences for measuring the rainfall erosion and their impact on RTS activity. For processing images photogrammetrically and generating digital elevation models PIX4D was used. Image adjustments and the difference calculations were done with QGIS. Unfortunately the created digital terrain models show a lot of large and small scale failures, which were so severe that a successful DTM differencing was not possible. Mass movement and erosion can be seen at some locations in the DTM, but accurate detecting or measuring of RTS dynamics was not possible with the data and the developed workflow. Therefore the influence of the heavy rainfall event of Summer 2021 remains unclear up to this point.