认清长江中下游当前的防洪形势及其变化历程,对长江流域下一步的防洪治理和开发保护至关重要。水利工程建设是长江防洪形势改善的主要措施,同时河湖自然演变引起的江湖关系调整也会给防洪形势带来较大影响。基于此,分析了20世纪60年代以来不同时期长江中下游江湖关系变化,模拟分析江湖关系变化对长江防洪形势的影响,在此基础上分析了三峡水利工程及上游控制性水库群的投运对长江防洪形势的改善情况,得到不同时期长江中下游防洪形势的变化过程。根据当前长江防洪形势及其变化趋势,进一步探讨提高中下游防洪保障能力的措施,如完善防洪工程体系、提升水利工程联合调度管理能力等。

A clear perception on the current and historic flood control situation in the midstream and downstream of the Yangtze River is of crucial significance for future regulation and protection. The construction of water conservancy projects is a dominant measure of improving the flood control situation; in the meantime, the adaption of river-lake relation to natural evolution also affects the flood control situation. In view of this, the changes in river-lake relation in different periods since the 1960s are analyzed, and their influences on flood control situation are simulated.Furthermore, the favorable effect of water conservancy projects, in particular, the Three Gorges Project and its upstream control reservoirs, on flood control situation is examined; hence the variation process of flood control situation in the midstream and downstream of the Yangtze River is obtained. In addition, measures to improve flood control capacity, inclusive of upgrading project system, and enhancing joint scheduling ability, are discussed.