3.3.2 Impact factor analysis
In Figure 12, the cumulative contribution of the top 10 environmental
factors in different seasons or regions is examined in relation to
stable snowpack. The results show that these top 10 factors account for
more than 85% of the overall contribution, suggesting their significant
influence on the distribution pattern of stable snowpack. Consequently,
this study focuses solely on analyzing the top 10 environmental factors
based on the magnitude of their contribution rate. In the Mamukao River
Basin (Fig 12(a,b)), there are variations in the dominant factors that
stabilize snowpack patterns during spring and winter. The three most
significant contributing factors in spring were Altitude (49.38%), Snow
Water Equivalent (Suwd) (21.72%), and Incoming Shortwave Radiation
(Asrad) (7.87%). Among these factors, Suwd (37.75%) and Altitude
(36.56%) had the highest replacement importance, indicating their
greater influence compared to other factors. The combined analysis of
contribution rates and replacement importance suggests that the
distribution pattern of stable snowpack in the Mamukao River during
spring is primarily influenced by Altitude, Suwd, and Asrad. In winter,
the top three contributing factors were Altitude (42.66%), Accumulated
Snow Depth (Awd) (17.2%), and Frozen Precipitation (Fpr) (7.81%).
Altitude (46.12%) and Fpr (33.45%) had the highest replacement
importance, indicating their significant influence on the distribution
pattern of stable snowpack in the Mamukao River during winter.
Therefore, the three main factors influencing the distribution pattern
of stable snowpack in winter in the Mamukao River are Altitude, Fpr, and
Awd.
In the Hanliu River basin (Fig 12(c,d)), the distribution pattern of
stable snowpack is influenced by different factors in spring and winter.
In spring, the three most significant contributing factors are Foa
(53.04%), Cra (27.58%), and Alt (13.63%), with Foa being the most
influential. The two factors with the highest replacement importance are
Alt (64.43%) and Foa (25.62%). Therefore, the dominant factors in
stabilizing the snowpack in the Hanliu River during spring are Foa, Cra,
and Alt. In winter, the three factors with the highest contributions are
Foa (29.58%), Wpr (20%), and Cra (14.14%), while the two factors with
the highest replacement importance are Alt (41.87%) and Und (26.43%).
Taking into account both the contribution rate and replacement
importance, the factors that have a greater influence on the spatial
distribution pattern of stable snowpack in winter are Foa, Wpr, Cra,
Alt, and Und.