The Impact of Topography on Snow cover in China

Alpine snow plays a vital role in regional hydrological cycles and climate systems. Topographic factors exert a significant controlling effect on snow cover distribution in mountainous areas. Understanding the complex relationship between snowpack distribution and topography will be helpful for more effectively estimate high-spatial resolution snow depth distribution. In this study, the snow cover variation with topographic factors (elevation, aspect, and slope) at different periods are analyzed based on remote sensing snow coverage fraction data from August 1, 2000, to July 31, 2020. A new method based on the snow cover area increase rate, is utilized to divide a snow season into three periods (accumulation, stable and melt periods). The variations in snow cover fraction (SCF) and snow cover days (SCD) with topographic factors, as well as their inter-annual changes, in the three different periods are analyzed in the three typical snow regions of China (Xinjiang, Tibetan plateau, Northeast China). The results indicate that the the influence of topography on snow cover distribution display different characteristics in the three typical snow regions and in the three snow periods.