Changes in the intra-annual distribution of precipitation and the dynamics of snowfall in the Kuznetsk Alatau Mountains

The article analyzes the changes in the annual precipitation on the western slope and in the axial part of the Kuznetsk Alatau Mountains from 1960 to 2020. This territory is interesting because it receives the largest annual precipitation for the whole of Western Siberia. Based on data of two meteorological stations operating in the area the climatic indicators of the amount of precipitation by months and average annual for the 30-year period from 1990 to 2020 are calculated. The results were compared with the data of the second half of the XX century. The results showed a steady upward trend in rainfall. So the average annual amount of precipitation according to the weather station “Nenastnaya” for the period 1950-1980 was 1,507 mm in the water layer and for the period 1990-2019 it was 1,650.7 mm. There is also a shift in precipitation towards the liquid phase. A pattern has been revealed: on average for the last 30 years, in the Kuznetsk Alatau Mountains 40% of the annual precipitation is accumulated in the snow cover and 60 % falls mainly in the liquid phase. The second part of the article describes the results of snow measurements in the Verkhnyaya Ters' river basin conducted from 2011 to 2020 within the most poorly studied and most humid part of the mountainous region. The literature data about the amount of precipitation in the near-watershed zone of the Kuznetsk Alatau is differ greatly: шn the “USSR Surface Water Resources” - up to 1,500 mm/year; by the calculation method by the flow modulus - up to 2,190 mm/year; according to the results of snow measurements in the southern part of the western slope of the Kuznetsk Alatau - up to 3,000 mm/year. Snow measurements showed that the height of the snow cover and liquid-water content in it on the western slope of the Kuznetsk Alatau directly depend on the absolute height of the place. From the foothills to the axial watershed, with an increase in the height of the place, the height of the snow cover and the liquidwater content in it is increase. Above 1,400 m, the depth of the snow cover decreases sharply due to the snow drift to the leeward slope, up to the complete absence of snow cover. In the subalpine zone of the windward western and southwestern slopes at the headwaters of the Verkhnyaya Ters' river, water content in the snow cover by mid-March accumulates up to 1,800 mm in the water layer. Thus, by the calculation method based on the updated climatic parameters, it can be assumed that the annual precipitation in 2020 can reach 3,000 mm per year or more. The results of snow measurements have shown that the maximum average annual precipitation in the Kuznetsk Alatau Mountains can be significantly higher than indicated in the climatic reference books. For the first time, the opinion that the value of the annual precipitation in the Kuznetsk Alatau Mountains reaches 3,000-3,500 mm and more was expressed by P.S. Spin. The results of the work confirm his assumption.

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