The 24th IAHR-APD Congress (24th IAHR-APD Congress)

167 / 2024-02-25 18:33:26

The evolution and reason analysis of runoff yield capacity in cold region under climate change

cold region, runoff ratio, climate change, path analysis

To understanding the runoff yield capacity (RR, the ratio of annual runoff and precipitation) is one of key prerequisites for efficient water resource utilization. Under dramatic climate change, significant RR had been found in some cold catchments. However, there are still obvious differences about the evolution and reason of the RR, for which long-term hydrohydrometeorology data of 315 cold catchments had been collected. The results showed that in the catchments with RR passing the significance test, the proportion of catchments with negative trend of RR (∆RR < 0) gradually increased, and the basin stations with ∆RR ranged from 49% to 67%, respectively, reflecting the decrease of runoff production capacity in cold regions. Further path analysis shows that in catchments with significant changes in RR, the trend change of RR can be attributed to the change of evaporation capacity (EP) and storage capacity (TWSP). EP plays a dominant role in the change of RR, and the median relative contribution (C_EP) of EP is −0.77, while the median relative contribution of TWSP to RR (C_TWSP) is −0.34. The results show that the variation of water storage capacity in cold region has a non-negligible control effect on the decreasing trend of RR. The research will help to enhance the understanding of hydrological cycle in cold basin and enhance the ability of water resources management in basin.