ИСТИНА

Polygonal peatlands with ice wedges are widely distributed in the southern tundra subzone of West Siberia. Thawing of ice wedges controls dynamics of polygonal peatland topography. Our study comprises two aspects (local and regional, respectively): (1) peatland monitoring in the key area in the northern part of Pur-Taz interfluve, and (2) analysis of remote sensing data covering polygonal peatlands in the North of West Siberia. Processing of current weather records and field monitoring of permafrost properties confirmed a fairly high rate of polygonal ice wedge degradation in the study area. Detailed assessment of key peatland monitoring data, including comparison of the rates of terrain changes in natural conditions and under the impact of the highway, as well as in the “peatland-lake” interaction zone was undertaken. Monitoring data allowed to extrapolate detected patterns to the entire north-eastern part of the Pur-Taz interfluve. Study of geological cross-section included determining peat composition and properties along with active layer depth measurements. This study was used to reveal transition and intermediate layers and their specific characteristic playing a buffer role in protecting permafrost. The results obtained allow us to develop the criteria for assessing the persistence of polygonal peatlands to anthropogenic impact along with considering modern climate changes, and create a respective “persistence of polygonal peatlands” map. Remote sensing of polygonal peatlands preliminarily allowed to define southern boundary of polygonal peatlands distribution in the North of West Siberia and gradual change of their features from the north southward.