4.4 Dominant factors stabilising snowpack distribution
At large scales, temperature and precipitation are the primary factors that influence the distribution of snowpack. However, at regional scales, additional factors, such as topography, play a significant role in contributing to the heterogeneity of snowpack distribution (Jiang et al. 2020,Li et al. 2023,Saydi et al. 2020). In this study, elevation played a significant role as the influencing factor for the stable snowpack during both winter and spring in both basins. The areas with high elevation predominantly exhibited the presence of a stable snowpack. This finding aligns with Chu et al.’s study on the spatial distribution of snow cover on the Tibetan Plateau, which indicated a positive correlation between elevation and snow cover extent. Specifically, their study demonstrated that higher elevations experienced greater snow cover (Chu et al. 2017). Additionally, the findings of this study indicate that the distribution of a stable snowpack is influenced not only by elevation but also by factors such as wind speed, radiation, and the proportion of subsurface area. In the Mamukao River Basin, wind speed emerges as the primary determinant in the distribution of a stable snowpack during winter and spring. The prevalence of high wind speeds in this region increases the likelihood of ”wind-blown snow” phenomenon, which, in turn, leads to sublimation, ablation, or redistribution of the snowpack. Consequently, this process significantly impacts the overall distribution pattern of the stable snowpack (Fujita et al. 2010). Radiation has implications for the distribution pattern of stable snow in the region. Specifically, the Tibetan Plateau experiences the highest solar radiation levels in China (Qi et al. 2014),The Mamukao River Basin is located in the inland area of the Western Sichuan Plateau. It experiences low precipitation and frequent sunny days, which leads to rapid snowmelt due to high radiation. In the Hanliu River Basin, the stability of snow distribution patterns is mainly influenced by land cover types and precipitation. The Hanliu River is situated in the alpine canyon area of the Hengduan Mountains. The vertical zoning in this area plays a significant role in determining the type of subsurface, which, to some extent, reflects the water and heat conditions of the region. Additionally, the rate of snow melting varies depending on different subsurface conditions (Zhang et al. 2014); The Mamukao River Basin is primarily characterized by grassland ecosystems, and the specific type of land has a minimal impact on the distribution pattern of stable snow. Consequently, the influence of the Mamukao River Basin on the subsurface is relatively limited, while it exerts a greater influence on the Hanliu River Basin. (Note: Please double-check the APA style guide for specific formatting requirements related to citations and references.)