Impacts of Yangtze Estuary Deepwater Channel Project and Hengsha East Shoal Siltation and Reclamation Project on Stagnation Point

Abstract:

Variation of stagnation point has significant influence on mouth bar formation and sediment deposition. A threedimensional hydrodynamic and salinity transport model based on MIKE 3 which has well been validated through observation data of tidal level, velocity magnitude and direction, and salinity was established to simulate and analyze the movement of the stagnation points caused by the Yangtze estuary deepwater channel project and the Hengsha east shoal siltation and reclamation project. It reveals that, ①Position of stagnation point is determined by an improved bottom average unitwidth flux formula, and the verification of stagnation point is good. ②Water depth and current speed has increased after construction of the Yangtze estuary deepwater channel project, the increase of ebb discharge is obviously large than the increase of flood discharge, and stagnation points move downstream in all bifurcations. ③After the Hengsha east shoal siltation and reclamation project, stagnation point moves about 5 km downstream in the North Channel and moves about 1 km upstream in both North Passage and South Passage.