The cryosphere change will intensify the summer drought in Qilian Mountains, northeastern of the Tibetan plateau

Abstract

Study regionThis study focuses on the upper reaches of Shule river (URSLH) and Heihe river (URHH) basins and Taolai river (URTLH) basin in Qilian Mountains. Study focusThe impact of the cryosphere changes on runoff components in basins with different cryosphere ratios. New hydrological insights for the regionTotal runoff (TR) increased in URSLH and URHH and decreased in URTLH, snowmelt runoff (SR) decreased in each basin, glacier runoff (GR) increased in URSLH and URTLH but decreased in URHH during 1980–2015. In the future, GR will increase under SSP585 and slightly decrease under SSP126 in 2040–2060 in URSLH and decrease in URHH and URSLH. The peak time of SR will advance by a month in each basin. In the future, GR (The ratio of the coefficient of variation (cv) of TR to cv of non-glacial runoff) will decrease, indicating hydrological regulation of glaciers will be weakened in these basins. SR and Rs (The ratio of summer runoff to spring runoff) will show downward trends, the processes of TR increase will be smoother. Rr (The ratio of maximum to minimum monthly runoff) will show downward trends under SSPs. TR will become smoother in each basin. Furthermore, the change of each runoff components will make TR tends to be smoother in the future and reduce TR especially in summer.