Abstract: Construction procedure and closure gap site selection for the dike-closing project in a large flood channel play a decisive role in the beach stability and success of the project.According to Qingcaosha reservoir research and practice,the mechanism of the shape formation and thestability of the flood channel in tidal estuary is analyzed,the research route for the construction procedure and the closure gap site selection of the dike-closing engineeringis introduced.Based on the study of river hydrodynamics b...