Figure 3 Rate of snowmelt in the Mamukao River Basin during spring and winter precipitation(a: Spring; b: Winter)
The snowpack in the Mamukao River Basin exhibited varying rates of change across the four altitudinal zones. This is supported by the observation that as the altitude increased, the rate of snowmelt decreased. Furthermore, the rate of snow decline in the spring remained lower than that in the winter. In altitudes below 4400 m (Fig 4(a, b)), the snow ablation rates were the fastest, measuring at -3.935%/d in spring and -4.037%/d in winter. It is important to note that the fitted curves were averaged out due to the absence of snow cover on day 6 in winter, resulting in larger slopes of the fitted curves than in reality. For elevations between 4400-4600 m (Fig 4(c, d)), the rate of decline was -0.852%/d in spring and -5.66%/d in winter. During spring, the proportion of snow cover stabilized at 85%, whereas in winter, it approached 0. In the interval of 4600-4800 m (Fig 4(e, f)), the rate of decrease in the proportion of spring snow cover was only -0.278%/d, whereas in winter, it was -5.051%/d. For altitudes above 4800 m (Fig 4(g, h)), the change in snow cover remained stable, with a rate of decrease of -0.139%/d in spring. However, in winter, the rate of decrease was relatively faster at -2.752%/d.