4.2 Differences in seasonal snowmelt of the Western Sichuan Plateau
The Mamukao River exhibits a broad distribution of stable snow during spring (see Figure x). The region encompasses 1682 raster sample numbers, of which only 276 represent non-accumulating raster samples. The remaining raster samples, which account for 85.6% of the total, indicate snow accumulation. The lack of specificity in these measurements may result in diminished accuracy of the prediction model. Consequently, the spring maximum entropy prediction model employed in this study yielded low accuracy for the Mamukao River (Jiang et al. 2020,Shuying et al. 2015). However, it has also been shown that radiation, windblown snow, and precipitation all contribute to the snowpack to some degree, and the influencing factors may vary between seasons (Alonso-González et al. 2020,Ding et al. 2023). In the Tian Shan region of Xinjiang, the snowpack extent is significantly influenced by temperature in spring and summer, while precipitation plays a predominant role in winter. In the western Sichuan Plateau, despite lower temperatures during winter compared to spring, snow retention is better (see Fig x), but winter precipitation is limited, and there are more clear days with strong solar radiation. As a result, the snowpack melts faster due to radiation. Additionally, the winter season in the western Sichuan Plateau experiences strong winds, which can cause snow transport and redistribution to lower elevations or sublimation in the atmosphere. On the other hand, in spring, although temperatures are higher, the abundant precipitation and fewer clear days result in reduced ability of the snowpack to absorb solar radiation. Furthermore, lower-altitude areas experience higher temperatures, leading to faster snowmelt. However, these areas have less snow distribution, mainly due to precipitation, whereas higher-elevation mountainous areas receive more snowfall, resulting in a widespread snow distribution. Consequently, snow variations in these areas are relatively stable, leading to a slower snowmelt rate in spring compared to winter.