黄河流域复合型水文干旱-高温热浪事件变化及相对贡献分析OA

Based on the calibrated data of ten global climate models of CMIP6 using quantile mapping method,the VIC distributed hydrological model was driven to simulate the runoff of the Yellow River Basin.The standardized runoff index was used to characterize hydrological drought,and the heat wave intensity was used to characterize heat waves.The change characteristics of future compound hydrological drought-heat wave events(compound events)were characterized from three dimensions,including duration,frequency,and intensity.And the relative contribution of single events and their interactions to the changes in compound events was quantified.The results indicate that hydrological drought events have obvious regional characteristics in future changes.The hydrological drought risk in the upstream Ordos Plateau region may increase,and the estimated drought duration in some areas of the upper and middle reaches may be shortened by 1-2 months,with a 25%to 50%decrease in intensity,compared to historical periods.With the increase in greenhouse gas emissions concentration and the passage of time,the duration,frequency,and intensity of heat waves and compound events in the Yellow River Basin have shown an increasing trend.Under three scenarios of SSP1-2.6,SSP2-4.5,and SSP5-8.5,the duration of the composite event is prolonged by 0.1-12 d,the frequency increases by 0.1-2 times per year,and the intensity increases by 10%-230%.The increase in heat waves is the main reason for the changes in future compound events.In most areas of the Yellow River Basin,the relative contribution of heat waves in the near future is 60%or more,and in the long term it will rise to 70%.The relative contribution of interaction to the changes in compound events is relatively low,with a proportion of 20%or less in both the near and far future periods.