APPLICATION OF REMOTE SENSING FOR PERMAFROST MONITORING IN ALASKA

• Main Author: Tcibulnikova, Iuliia V.
• Format: Text
• Language: unknown
• Published: Digital Commons @ Michigan Tech 2021
• Subjects: remote sensing; NDWI; permafrost; thermokarst lakes; Alaska; Geological Engineering; Ice; Prudhoe Bay; Thermokarst; Tundra
• Online Access: https://digitalcommons.mtu.edu/etdr/1192; https://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=2349&context=etdr

Permafrost covers about 85% of the state of Alaska; it is a fragile cryogenic phenomenon prone to degradation under thermal and mechanical (natural and anthropogenic) influences. This research analyzes the application of remote sensing for permafrost monitoring in the Prudhoe Bay area, Alaska. Thawing thermokarst lakes are assessed as the signs of permafrost degradation. Normalized Difference Water Index (NDWI) was used to detect thaw lakes in Landsat-8 satellite imagery within the 529-km2 study area in 2013 and 2020. The lakes were then mapped according to their size and growth rate. Lakes do not grow uniformly; some lakes grow while other lakes decrease in size. Very small lakes are found to have higher growth rates; they are shallower, so their area rapidly increases with influx of precipitation. Lakes have been observed to merge together. Lakes are less abundant in the south-western part of the study area, where the ground surface elevation increases and ground ice content decreases from high to low. The network of roads in the study area was determined to affect the distribution of lakes. The cumulative area of thaw lakes has increased over the study period. However, the number of lakes has decreased. Factors affecting the spatial distribution of lakes were assessed, such as the ground ice content and cumulative precipitation. The NDWI method has proven itself useful for open water and wetland detection in the tundra plains setting. Limitations of the method’s application were documented.