ИСТИНА

Seasonal snow cover is a fundamental component of the global climate, energy and water cycles. In the southern regions of Siberia snow is an essential factor in runoff formation, sustainable agricultural production and ecosystem functioning. In recent decades snowpack duration has shown a tendency to decrease, as in many regions of the world. However, the average snow depth has been consistently increasing in open areas and decreasing in forested areas. Considering that snow cover is highly variable at multiple scales, it’s becoming increasingly difficult to predict watershed response to environmental change. Within the framework of the South Siberian Snow Cover project (SSSC), we are planning to focus on (1) estimating variability of snow cover at multiple scales, (2) comparing the features of snow accumulation in different landscapes (from dry steppe to low mountains), (3) collecting data of the main snow properties (depth, density and SWE), which will be available for further studies. The project will be implemented jointly by Lomonosov Moscow State University and the Institute for Water and Environmental Problems SB RAS in 2019 – 2022. The study area located in the Altai region, which is a large agricultural region with high population density in the South of Western Siberia. This territory is extremely diverse, there are areas both suffering from desertification and areas with high flood risk. Within the framework of the SSSC project, observations will be carried out in three catchments: Kuchuk (steppe), Kasmala (forest-steppe), Mayma (low mountains). In each catchment we are planning to use a stratified nested sampling design. The watershed will be stratified into several strata by topography, vegetation (land cover) and elevation (for the mountain catchment). Within each strata 60 snow depths and 12 snow densities will be measured along two perpendicular transects (60x60 m plots). Observations will be carried out once a month during the winter (November-March) at 4-5 key plots in each catchment. During the period of maximum snow accumulation (at the beginning of March), extended snow surveys will be conducted on all plots (30-40 plots per catchment). One of the specific objectives of the SSSC project is the integration of hydrological and landscape ecological methods in snow science. We are planning to assess the isotopic composition of snow (δ18О, δD) which is widely used as a tracer of internal fluxes. At some plots depth of soil freezing will be measured, which is also one of the most significant parameters of winter ecosystem functioning. Besides, it is planned to explore snow distribution depending on the landscape structure parameters calculated using landscape indices. The main potential results that we are planning plan to achieve are SWE distribution models, as well as the comparative analysis of the snow parameters variability at multiple scales (plot, catchment, between catchments). We suppose it necessary to make the observational data available to a wide range of researchers, taking into account that not so many studies dedicated to Siberian snow cover have been published.