5 Conclusions
In this study, we compared the formation process and distribution pattern of stable snowpack during winter and spring in two typical areas of the western Sichuan Plateau: the Mamukao River Basin and the Hanliu River Basin. We utilized the MODIS day-by-day cloud-free snow cover dataset for our analysis. Additionally, we comprehensively analyzed 33 environmental factors to identify the dominant factors influencing the distribution of stable snowpack in the two basins during winter and spring. The following conclusions were drawn:
(1) The snow ablation rate is higher in winter compared to spring on the western Sichuan Plateau, with the Mamukao River Basin experiencing a greater ablation rate than the alpine valley area. In spring, the snow ablation rate generally decreases with increasing altitude in both the Mamukao River Basin and the Hanliu River Basin. Conversely, in the Hanliu River Basin during winter, higher altitudes correspond to a faster snow ablation rate. Furthermore, the ablation rate in the Mamukao River Basin exhibits little variation across different slope directions during winter and spring, whereas the Hanliu River Basin shows significant variation in ablation rate across different slope directions during these seasons.
(2) During seasons other than winter in the Hanliu River Basin, the stable snowpack is predominantly found in high-altitude areas. Moreover, the area covered by stable snowpack increases with higher altitudes. However, in the Hanliu River Basin during winter, the stable snow cover is primarily distributed in areas with altitudes ranging from 4000-5000m.
(3) Elevation is a dominant factor influencing both the Mamukao and Hanliu River basins during winter and spring, although the impact of other factors varies across different seasons and regions. Specifically, the Mamukao River Basin is more significantly affected by wind speed, radiation, and precipitation, whereas the type of subsurface plays a major role in influencing the Hanliu River Basin.