The first results of monitoring the development of polygonal relief in the peatland-lake interaction zone in the Northern Pur-Taz interfluve from 2021 to 2023

Since the last century, the monitoring of permafrost rocks, which involves observing changes in the depth of seasonal thawing and temperature, has been conducted across a wide geographical area. However, an increase in the cumulative average daily positive air temperatures and the average annual air temperature has significantly activated cryogenic processes in the northern part of Western Siberia. Since 2016, extensive and thorough research on permafrost polygonal peatlands has been undertaken in the Pur-Taz interfluve area. In 2021, a study was initiated to observe changes in polygonal relief and the upper layers of permafrost, which are affected by natural processes occurring in peatlands near lake shores. An assessment of changes in polygonal relief in the peatland–lake interaction zone of polygonal peatlands has been conducted as a result of exogenous processes against the background of modern climatic fluctuations. This study used field methods and approaches, including the establishment of monitoring sites to observe geocryological conditions and the use of unmanned aerial vehicles to assess changes in relief and manifestations of cryogenic processes along lake shores. The results of the field observations were analyzed using both classical statistical methods and specialized software for processing orthophotoplans and digital terrain models obtained from unmanned surveys. These findings were subsequently compared with satellite images. Several climatic and landscape factors affecting polygonal peatlands in the peatland-lake interaction zone were identified. Thus, the accumulated monitoring data from multiple sites within this zone, combined with results from key peatlands in the research area, allowed us to draw preliminary conclusions regarding the general dependence of polygonal peatland degradation along lake shores on the wave action of lake water, which is influenced by the wind rose of the research area. This degradation occurs against the background of contemporary climatic fluctuations and the differentiation of other contributing factors, including the landscape-geomorphological conditions of the monitoring sites.