中文摘要：

以北江飞来峡水库上游为研究对象,构建了网格分辨率为0.25°×0.25°的VIC（Variable Infiltration Capacity）水文模型,应用CMIP5多模式输出的降尺度结果与VIC模型耦合,对RCP2.6、RCP4.5和RCP8.5情景下未来时期（2020—2050年）飞来峡水库的入库洪水进行预估,并根据IPCC第5次评估报告处理和表达不确定性的方法来描述预估结论的可信度。结果表明,2020—2050年飞来峡水库年最大洪峰流量和年最大7日、15日洪量在RCP2.6情景下＂大约可能＂呈增加趋势,在RCP4.5和RCP8.5情景下＂较为可能＂呈增加趋势,水库防洪安全风险增大。与历史时期（1970—2000年）相比,未来水库极端入库洪水增加的可能性从大到小依次为RCP4.5、RCP2.6和RCP8.5情景,其中设计洪水100年、50年和20年一遇的洪峰流量在3种排放情景下均呈上升趋势,100年、50年和20年一遇的最大7日、15日洪量在RCP4.5情景下以上升为主,而在RCP2.6和RCP8.5情景下则主要呈减少态势。

英文摘要：

In this paper,the downscaling results of the multi-model dataset from the Coupled Model Intercomparison Project Phase 5（ CMIP5） were coupled with the Variable Infiltration Capacity（ VIC） model to predict future floods of the Feilaixia reservoir in the Beijiang River basin under RCP2. 6,RCP4. 5,and RCP8. 5 scenarios. Credibility of the projected changes in floods is described using an uncertainty expression approach,as recommended by the Fifth Assessment Report（ AR5） of the Intergovernmental Panel on Climate Change（ IPCC）. The results indicate that annual maximum flood peak and maximum 7-day and 15-day flood volumes during 2020—2050 would be ＂about as likely as not＂to show an upward trend under the RCP2. 6 scenario and ＂more likely than not＂to show an upward trend under the RCP4. 5 and RCP8. 5 scenarios. Compared with the 1970—2000 historical period,the flood peaks in the 100 a,50 a,and 20 a return periods are projected to increase under all future scenarios. In contrast,the maximum 7-day and15-day flood volumes in the 100 a,50 a,and 20 a return periods would increase under the RCP4. 5 scenario and decrease under the RCP2. 6 and RCP8. 5 scenarios.