ИСТИНА

The state and transformation of the natural and natural-technogenic geosystems in permafrost zone are determined by interaction of geological medium with external Earth's spheres, primarily - with the atmosphere. The ascending brunch of the global climate fluctuations is documented up to date.Established at the turn of the centuries XX and XXI a slowdown of the tempreture increase both for air and for soils hasn't appeared to pe a top part of the sinusoid, as it was expected previously. This fact increases the relevance of the continuation of the observations. Comprehensively studied areas inside permafrost territory of Russia are specific “key sites”, which permit extrapolation and interpolation of the information with a help of geosystematic approach. Corresponding cartographic model is called to supply the information on background and current natural and technogenic conditions for any site of the territory with required precision and reliability as well as to serve as a basis for forecast of changes in permafrost zone. The monitoring observations provide iterative correction of permafrost cartographic models. General direction of changing of climate parameters is unfavourable for permafrost development. So a group of monitoring sites in the Western Siberia, compiling regional transect from Northern taiga to high latitude arctic tundra, has pointed out the rise of mean annual air and soil temperatures, increase of snow cover thickness as well as consequent increase of active layer thickness up to formation of residual thaw layer areas in Northern taiga and forest tundra. According to model forecasts in the Northern regions of Russia, including Yamal peninsular, mean annual air temperature can rise 1,5…2,5°С by 2030, 4°С - by the middle of XXI century and will exceed 5°С - by the end of XXI century! At the same time the forecast suggests the rise of snow cover thickness and estimates 10-15% precipitation amount increase by 2030. Together it will lead to significant decrease of ground strength and stability of landscapes. Already now 5-30% ground carrying capacity decrease is pointed out in permafrost zone of the North of Western Siberia, with maximal decrease being correspondent to the arc along the main cities (Salekhard, Nadym, New Urengoy and further in Norilsk city direction). It testifies that for constructions build about 25-40 years ago, with the reserve of strength varying in the range 1,2-1,4, the reserve of ground strength has been practically exhausted because temperatures of underplayed mineral rocks have approached 0°С. At the South margin of permafrost zone the thawing of permafrost islands is going on under peat deposits and frost mounds. This fact is of great significance for linear constructions. The study has been fulfilled due to support of RFBR (grants № 14-05-00956, 15-55-71004\15, 16-05-00249, 16-45-890257-ЯНАО), RSF (grant № 16-17-00102), international programs TSP, CALM, GTN-P, PEEX, SWIPA, GCW, administration of YANAO, GazpromDobychaNadym, GazpromDobychaUrengoy and Northgaz companies.