多年冻土退化下黄河源区径流演变与退水分析OA

In recent years,global climate warming has led to permafrost degradation,which has signifi-cantly influenced the hydrological cycle.To quantify the effects of permafrost degradation on the evolution of runoff and groundwater,WaSiM,a water-heat coupled transfer model,was employed to simulate per-mafrost dynamics,runoff components and groundwater in the headwater region of the Yellow River(HW-YR)from 1980 to 2020.The results indicate that the degradation rate of permafrost coverage in HWYR reached 5%per decade.Permafrost degradation increased total runoff,direct runoff,baseflow,and groundwater depth,while reducing interflow.Complete permafrost degradation would increase total annu-al runoff by 784 million m3,and groundwater depth by 11.55 m in HWYR.Seasonal responses of runoff components exhibited marked variations;however,the magnitude of these responses weakened after 2000,with the most pronounced reduction observed in the seasonally frozen ground(SFG)region,indi-cating significant permafrost degradation.Permafrost degradation also slowed the recession process,there-by enhancing the catchment's capacity of runoff regulation;whereas its effect in SFG remained limited.The in-depth investigation into the responses of runoff components contributes to a better understanding of runoff characteristics and dynamics,providing a scientific basis for water resources management and eco-logical conservation.