Characteristics of runoff changes and their climatic factors in two
different glacier-fed basins
The hydrological regulation function of glaciers in different watersheds
is different. This study took the Yanggong River Basin (YRB) and Urumqi
River Basin (URB) as two typical cases, to explore the runoff change
differences and their responses to climate factors during 1979-2017
using the Mann–Kendall test and correlation analysis method. In the
past 39 years , the annual runoff in the YRB showed
insignificant trend of increasing first and then decreasing. In
contrast, the URB’s increasing trend was significant. In the YRB, from
the 1980s to the 2010s, the monthly runoff extremum occurred earlier
than before, and the peak value is decreased. The time of monthly runoff
extremum in the URB has not changed, but the peak value is increasing.
Both basins showed an increasing trend in the annual temperature from
1979 to 2017, and the temperature rise in the URB was faster than in the
YRB. The precipitation in the two basins did not show a significant
increase or decrease trend from 1979 to 2017. The main influencing
factor of runoff change in the YRB is the precipitation during flood
season. The temperature rise causes an accelerated melting of the
glaciers and snow cover, which, in combination with the summer
precipitation change, contributed to the increase of runoff in the URB.
In continental glacier basins with many glaciers, the regulation
function of glaciers on total runoff is more significant.