中文摘要：

从第5次耦合模式比较计划（CMIP5）的47个全球气候模式中，根据模式对珠江流域降水模拟的相似性，筛选出5个相对独立的模式，耦合大尺度水文模型（VIC模型）模拟了21个主要干支流控制站日流量过程。以洪峰流量和洪水总量为指标，评估了IPCCRCP4．5情景下未来30年洪水对气候变化的响应。结果表明：2011—2040年洪峰流量和洪水总量在西江和粤西桂南沿海诸河可能呈增加趋势；而在北江（洪水总量）和东江多半可能呈减少趋势。与1970--1999年相比，郁江、桂江、东江及粤西桂南沿海诸河特大洪水可能呈增加趋势，红水河和北江多半可能呈增加趋势；柳江则可能或多半可能呈减少趋势。西江洪水与红水河、郁江关系将更为密切，北江与西江及红水河与柳江洪水遭遇的情况多半可能增加。

英文摘要：

Based on five relative independent global climate models from the multi-model ensemble of 47 global climate models within World Climate Research Program＇s Coupled Model Intercomparison Project Phase 5 （CMIP5） and the VIC （Variable Infiltration Capacity） model, flood response to climate change in the Pearl River＇ basin under the new Intergovernmental Panel on Climate Change （IPCC） representative con- centration pathways （RCPs） 4.5 scenario for the next three decades was assessed in this study. The results show that upward trends are likely detected on the results of Mann-Kendall test at most gauges in the Xiji- ang River and the coastal various rivers during 2011-2040, and downward trends are more likely than not found in the Noah River （for the annual maximum 15d mean stream flow series） and the East River dur- ing that period. But most of these trends are not significant. Relative to the baseline period （1970-1999）, the projected extraordinary flood would be likely increased in the Yujiang River, the Guijiang River, the West River and the coastal various rivers, and in the Hongshuihe River and the North River, there are more likely than not to increase. Only in the Liujiang River, the projected extraordinary flood would be likely or more likely than not to decrease. The source of flood at Gaoyao gauge would be likely more relat- ed to the Hongshuihe River and the Yujiang River. Flood encountering risk would be more likely than not to increase for the North River and the West River, and that is also found for the Hongshuihe River and the Liujiang River.