论述了三期明渠提前截流方案的综合比较分析及截流水力学试验研究成果。认为拟定的提前截流诸方案各有利弊，其截流难度较初设方案显著增加。对于截?quot;基本方案"及"比较方案"的成功实施，必须辅之以一定的工程技术措施降低截流难度。论述了三期明渠提前截流方案的综合比较分析及截流水力学试验研究成果。认为拟定的提前截流诸方案各有利弊，其截流难度较初设方案显著增加。对于截?quot;基本方案"及"比较方案"的成功实施，必须辅之以一定的工程技术措施降低截流难度。

The inadvance closure schemes and their reasearch findings on Three Gorges Project's (TGP's) 3rdstage open channel closure are discussed in the article. It is considered that there are some advantages and disadvantages for every closure scheme, but their construction difficulties obviously increasethan the original scheme. For successfully implementing the basic scheme and comparative scheme ahead of time, some measures to decrease the difficulties of closure must be adopted.