三峡工程建成后长江中游的防洪形势和解决方案（II）

 针对第I部分提出的三峡建成后长江中游防洪形势和问题，用相同模型研究了多种代表性措施的防洪效果，提出了应对长江中游防洪问题的综合解决方案。研究显示，牌洲裁弯、提高城陵矶设计洪水位和南北分洪等工程和调度措施单独使用，在三峡水库提供和《长江流域防洪规划》确定的条件下都难以保证长江中游再现1954年洪水的安全。按防御1954年洪水和保障荆江安全目标，本文通过大量方案计算比较，提出基于牌洲裁弯与南北分洪组合，以适当提高城陵矶设计洪水位为调度余地的综合方案。该方案在调度和运用条件等方面有较大的安全余地，可以更好适应三峡水库等影响下长江中游的河流变化。

The Mid-Yangtze Flood After the Commencement of the Three Gorges Project and the Countermeasures (Ⅱ)

To relieve the serious threat of flood in mid-Yangtze after the commencement of the Three Gorges Project (TGP) as predicted in the first part of this paper, some representative measures of mitigation so far proposed are simulated and analyzed with the same model for mid-Yangtze river-net. Such measures as to cutoff the Paizhou bend (CPB), to raise the stage of flood diversion at Chenglingji (RSD) and to divert flood in south and north sides of Jingjiang reach (DNS) are all shown to be effective but not enough for the safety of the mid-Yangtze if being applied separately with conditions provided by TGP and the designed Flood Diversion Areas (FDA) approved by the central government. Based on a great number of computations for many scheme combinations, a comprehensive scheme that combines CPB and DNS with RSD as auxiliary operation measures is proposed, which is shown to be capable of protecting the mid-Yangtze against the flood of 1954 and having enough rooms to cope with certain uncertainties of river deformation that might be brought about by the trapping of sediments and flow regulations of the TGP and others.