Thermokarst Lakes of Taiga and Tundra Zones of the Siberian Arctic Based on Kanopus-V and Sentinel-2 Images

Abstract—The patterns of size distribution of thermokarst lakes in the tundra and taiga Arctic zones of northeastern Siberia have been studied based on space images from the Kanopus-V and Sentinel-2 satellites (with spatial resolutions of 2.1 and 20 m, respectively) acquired in the summer months of 2017–2021. The lakes are interpreted on a mosaic of Sentinel-2 satellite images and on 16 test plots (TPs) on Kanopus-V images in order to determine the number of lakes and their areas within each of the specified zones. Experimental histograms of distribution of the number and total areas of lakes by their sizes are obtained for the studied tundra and taiga zones in an extremely wide range of lake sizes from 50 to 10⁸ m² based on the integration of data from images of different spatial resolution. The histograms of the distribution of the number of lakes by their sizes demonstrate a similar behavior in both zones, manifested in the growth of the number of lakes as their sizes decrease. It is shown that the main contribution to the total area of lakes is made by large lakes (more than 200 000 m²), the share of which exceeds 80% of the total area of lakes (in the tundra 82% and in the taiga zone 85%). The contribution of small lakes (less than 500 m²) to the total area of Arctic lakes in both tundra and taiga zones is negligible and does not exceed 0.20–0.17%, respectively. The characteristics of lake density and the degree of lake coverage of the studied territories are studied. It is shown that the lake coverage and density in the tundra is 1.9 and 2.5 times higher than in the taiga zone.