Session2: Ports, Coastal Engineering and Management
Title: NUMERICAL ANALYSIS ON IMPACTS OF THE PROJECT OF NORTH BRANCH NARROWING ON SEDIMENT DISTRIBUTION
Guo Chuansheng, Tang Liqun, Wang Yuhai, Zhao Huiming
In order to analyze the effects of middling narrowing project in the north branch plane on the sediment transport in Yangtze estuary, a two-dimensional mathematical model of average tidal current and sediment in Yangtze estuary was established. Based on the verification of the model with measured data, the hydrodynamic and suspended sediment concentration changes before and after the middling narrowing project were simulated and analyzed. The results show that after the implementation of the middling narrowing project, the flow capacity of north branch entrance declined due to the water blocking and narrowing effects caused by the project; the speed of flood/ebb tide decreased in the downstream estuary; time lags appeared for flood/ebb tide comparing with the situation before the project; moreover, the sediment concentration in the north branch river channel decreased, with section peak sediment concentration decreasing 0.0%~-14.9%. The impairing effect of this project on the intensity of sediment transport in the north branch gradually increased from downstream to upstream, while the tide level, flow velocity, and sediment concentration in the south branch were less affected by the project.