未来气候变化对东江流域径流的影响预估

Estimation of the Effect of Future Climate Change on the Runoff of Dongjiang River Basin

基于基准期(1986—2005年)观测数据和未来近期(2023—2042年)、中期(2051—2070年)和远期(2079—2098年)气候模式预估数据,采用分布式水文模型(SWAT模型),预估了未来气候变化对东江流域径流的影响。结果表明:流域径流总体呈增加趋势,RCP8.5情景下径流增加速率大于RCP4.5。除RCP4.5情景下在未来中期径流较基准期减少6.2%外,其他时期和情景下径流较基准期增加2.8%~12.7%;RCP8.5情景下,在未来不同时期的第2季度和第3季度径流均较基准期增加,流域出现洪涝灾害风险加大;第1季度和第4季度径流均较基准期减少,叠加气候变暖背景,未来高排放情景下可能会加剧东江流域冬春季的水资源短缺。

Based on the observations for a base period(1986-2005)and the estimations by a climate model for the near future(2023-2042),intermediate future(2051-2070)and distant future(2079-2098),this work uses the SWAT,a distributed watershed hydrological model,to estimate the effect of future climate change on the runoff of the Dongjiang River basin.The results are shown as follows.The basin runoff shows a generally increasing trend by rates larger with the scenario of RCP8.5 than with that of RCP4.5.Except for the RCP4.5 scenario under which the runoff is expected to lessen by 6.2%than the base period in the intermediate future,it will be 2.8%to 12.7%more than the base period in the remaining periods and scenarios.Under the scenario of RCP8.5,the runoff for the second and third season of the year will all be more than the base period for all future periods,increasing the risk for the basin to have flooding damage.The runoff for the first and fourth season will be less than the base period.With the background of climate warming taken into account,it may escalate the shortage of water resources in the winter and spring of the Dongjiang River basin under the scenario of high emission levels.