An accurate assessment of flood control capacity of a reservoir is a prerequisite for ensuring the safety of flood control works. This study used the method of adding side reservoirs and used MIKE11 to establish a one-dimensional hydrodynamic model of the Three Gorges Reservoir (TGR). Based on the combination of the dynamic reservoir capacity flood control and the separation of the outflow of the Jingjiang Three Outlets, the flood control capacity of the TGR was assessed. The results showed that the TGR can effectively withstand large floods below the magnitude of 100-year return period discharge. For a rare flood event in 1,000 years recurrence interval, it is necessary to use the Jingjiang flood diversion area for ensuring the safety of downstream floodplains along the main river course. As far as exceptionally large floods with the return frequency of 0.01% or lager magnitude concerned, this extreme high flow cannot be safely impounded by the TGR even if the Jingjiang flood diversion area is adopted. Therefore, a series of upstream cascade reservoirs are suggested to be fully utilized for a joint flood control strategy.

中文翻译：

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三峡工程对不同频率洪水的防洪能力

准确评估水库防洪能力是确保防洪工程安全的前提。本研究采用添加侧水库的方法，并利用MIKE11建立三峡水库(TGR)的一维水动力模型。结合动态库容防洪与靖江三口出水分离，对三峡大坝的防洪能力进行了评估。结果表明，TGR能有效抵御100年一遇泄洪量级以下的大洪水。对于每1000年一遇的罕见洪水事件，需要利用靖江分洪区来保障主要河道下游洪泛区的安全。对于返水频率为0.01%或更大的特大洪水，即使采用靖江分洪区，这种特大流量也不能被三峡大坝安全拦蓄。因此，建议充分利用一系列上游梯级水库作为联合防洪策略。