松澧地区是澧水与长江分流道松滋河两水交汇的地区，历来为洞庭湖区洪涝灾害最为严重的地区之一。基于对澧水及长江洪水特征、两水洪水遭遇情况分析，论证了松滋口建闸对松澧洪水进行错峰调度具备水文基础条件，并提出了受下游水位顶托的松澧河网区河道安全泄量计算方法与结果、松澧地区超额洪量计算途径和松滋口闸错峰调度原则，在此基础上，分析了松滋口闸错峰调度对减少松澧地区典型年超额洪量的作用。结果表明，利用松滋口闸对松澧洪水进行错峰调度，可以大幅减少松澧地区大洪水年份超额洪量。

Song－Li Ｒegion is the confluence area of the Lishui Ｒiver and branch of the Yangtze Ｒiver，the Songzi Ｒiver，and it is among the regions of Dongting Lake which suffers from the flood disaster most seriously in history． Based on an analysis of the flood characteristics of the Lishui Ｒiver and Yangtze Ｒiver，and the flood encounter condition between two rivers，the hydrological basic conditions for peak alternation regulation of Songzi Ｒiver and Lishui Ｒiver flood with Songzi flood－regulating sluice is qualified，the calculation methods and results of safe discharge capacity of river channels influenced by downstream backwater in Song－Li Ｒiver network area，calculating approaches of excess flood volume of Song－Li Ｒegion and principles of flood peak alternation regulation by Songzi flood－regulating sluice are proposed． On this foundation，the reducing effect on the excess flood volume of Song－Li Ｒegion by flood peak alternation regulation with Songzi flood－regulating sluice in typical flood years is analyzed． The results show that the excess flood volume of Song－Li region in large flood years will be drastically reduced by peak alternation regulation of Songzi Ｒiver and Lishui Ｒiver flood with Songzi flood－regulating sluice．