3.1.1 Mamukao River
In the Mamukao River Basin, there are differences in snowmelt processes
between spring and winter. During spring (see Fig 3(a)), the rate of
snowpack ablation was slower. Snowfall increased the proportion of snow
cover in the watershed to 96.56%, and within 7 days after snowfall, the
snowpack changed more slowly, with the area decreasing by only 2.96%.
However, the rate of snow ablation accelerated during days 8-11, and the
area decreased by 3.24%. It started to level off at day 12, and then
the next snowfall occurred at day 14, causing the snowpack area to
rebound. This snow ablation process had an ablation rate of
-0.707%/day. During winter snowfall (see Fig. 3(b)), the snowfall
increased the proportion of snow area in the watershed to 99.18%, and
the proportion of snow cover on day 2 was 96.73%, which was less
variable. From day 3 onwards, the proportion of snow cover declined
sharply, and the snow-covered fraction (SCF) decreased by 75.16% in the
period of days 2-10, after which the trend of change became stable. The
rate of decline was -5.216%/day in 17 days, which was much larger than
the spring snow ablation rate. Therefore, the spring snow ablation rate
is less than the winter snow accumulation in the Mamukao River basin.