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.

Taking the Yangtze River Source Basin (YRSB) and Shule River Basin (SRB) as two typical cases, the sustainability of the water resources in these two basins was evaluated using the Level of Water Stress (LWS) from Sustainable Development Goal (SDG) 6.4.2, and the regulating effect of the glacier runoff on the LWS was quantified. From 2000 to 2030, the level of socioeconomic development in the YRSB is low, and the total water consumption is only about 0.18×10 8 m 3 whereas the SRB has a relatively high level of socioeconomic development and total water consumption is about 10×10 8 m 3, i.e., 50 times higher than that in the YRSB. For the above reasons, the SRB’s LWS is much higher than the YRSB’s, resulting in a very low sustainability of water resources. As natural assets, glaciers flow downstream in runoff mode, so compensation at the watershed scale should be considered. In the basin, the optimal allocation of water resources is needed. At the inter-basin scale, the compensation mechanism of glacier water resources needs to be improved.