【摘要】 研究气候变化对长江源区地表径流的影响，为长江源区水资源开发与保护提供依据.基于1980—2021年地表径流数据，运用线性回归法对地表径流年际、年内变化趋势进行分析，运用CMIP5模型中的21种模式的模拟结果，结合RCP_S的三种气候情景(RCP2.6、RCP4.5、RCP8.5)并耦合SWAT模型下，预测未来(2022—2100年)长江源区地表径流的变化趋势.结果表明：1980—2021年地表径流年际变化较大，在2009年年际径流最大，总体呈现上升趋势；3—7月地表径流量上升，7—12月径流量逐渐下降，12—3月径流量平稳.除1980—1982年、1983—1985年降水量与径流量相关性不显著外，其余年份均呈显著状态(P<0.05).用建立好的SWAT模型在长江源区进行模拟，率定期的决定系数为0.81,模拟径流量与实测径流量误差为6.44%,验证期的决定系数为0.86,误差为4.60%,模拟数值符合度较高，SWAT模型在长江源区较为适用.三种气候情景下，地表径流的年际变化较大，总体呈现下降趋势；RCP2.6情景下，2048年径流量最大；RCP4.5情景下，2035年径流量最大；RCP8.5情景下，2036年径流量最大.三种气候情景下，地表径流年内变化较大，且年内分配不均匀，3—8月径流量上升，8—12月径流量下降，12—3月保持平稳；RCP4.5中径流变化最大，RCP8.5中径流变化最小.未来气候情景下，长江源区径流量将下降，加强水资源保护迫在眉睫.更多还原

【Abstract】 The impact of climate change on surface runoff in the source area of the Yangtze River is studied to provide a basis for water resources development and protection in the source area of the Yangtze River. Based on the surface runoff data from 1980 to 2021,the linear regression method is used to analyze the inter-and intra-annual trends of surface runoff, and the simulation results of 21 models in the CMIP5 model are used to predict the future(2022-2100)trends of surface runoff in the Yangtze source area River under three climate scenarios(RCP2.6,RCP4.5,RCP8.5)of RCP_S and coupled with the SWAT model. The results show that the interannual variation of surface runoff from 1980 to 2021 is large, and the interannual runoff is the largest in 2009,with an overall increasing trend, the surface runoff increases from March to July, decreases gradually from July to December, and is stable from December to March. The correlation between precipitation and runoff was significant(P<0.05)in all years except for 1980-1982 and 1983-1985,correlation was not significant. The established SWAT model was used to simulate in the source area of the Yangtze River. The coefficient of determination for the rate period was 0.81,the error between the simulated runoff and the measured runoff was 6.44%,and the coefficient of determination for the verification period was 0.86 and the error was 4.60% higher, the SWAT model is more applicable in the source area of the Yangtze River. Under the three climate scenarios, the interannual variability of surface runoff is large, and the overall trend is decreasing, the maximum runoff is in 2048 under RCP2.6,2035 under RCP4.5,and 2036 under RCP8.5. Under the three climate scenarios, surface runoff varies greatly within the year and is unevenly distributed within the year, with runoff increasing from March to August, decreasing from August to December, and remaining stable from December to March; runoff varies the most in RCP4.5 and the least in RCP8.5. Under the future climate scenario, the runoff in the source area of the Yangtze River will decrease, and it is urgent to strengthen water conservation.更多还原