On Oct. 30, 2015, Management Center of Transport Science and Technology, China Academy of Transportation Sciences organized an acceptance meeting in Shanghai to assess MoT Applied Basic Research Project “Dynamic Process of Fine Sediment and Waterway Back-Silting Mechanism at the Yangtze River Estuary”. NHRI participated in the research of Special Subject 5 of the project, Numerical Modeling of Waterway Back-Silting in North Passage of the Yangtze River Estuary. The expert panel consisted of experts with SDC Waterway Construction Co., Ltd., CCCC Shanghai Dredging Co., Ltd., Zhejiang Institute of Hydraulics & Estuary, East China Normal University, Shanghai Branch of Changjiang Institute of Survey, Planning, Design and Research, Changjiang Waterway Bureau, Zhejiang University, Hydrology and Water Resources Survey Bureau of the Yangtze River Estuary, etc. The project team members from the project lead agency of Shanghai Estuarine & Coastal Science Research Center, and the project participating agencies of Tianjin Research Institute of Water Transport Engineering, Nanjing Hydraulic Research Institute and Shanghai Waterway Engineering Design and Consulting Co., Ltd. attended the meeting. After listening to the report made by the project team and reviewing relevant technical document, the expert panel unanimously agreed that the project had reached the expected research targets with fulfilled research tasks and complete technical and financial files.

In order to break through the key issues in the study of water-sediment movement and back-silting of deep waterway of the Yangtze River Estuary, a series of focus problems in estuarine sediment study, such as flow field characteristics, near-bed kinetic characteristics of fine silt, sediment source of the North Passage, sediment flocculation and hydrodynamic features, waterway back-silting mechanism and numerical forecast of back-silting quantity under the context of tidal unsteady flow and sea water and freshwater intersection with the research measures of field observation, hydrological data analysis, in-door experiment and numerical modeling.   Research findings include: 1) Systematic disclosure of the dynamic process of flow and fine sediment in the North Passage of the Yangtze River Estuary, and the mechanism of large amount of deep waterway back-silting and its high concentration during flood season and at the middle of the waterway for the first time; 2) First revelation of the significant impact of sediment transportation over the south jetties on back-silting of deep waterway with the help of water and sediment fluxes analysis; 3) Gain of a series of kinetic property parameters and calculation formulae of fine silt by setting up the observation system of near-bed current and sediment at the Yangtze River Estuary for the first time incorporated with in-door experiments; 4) Independent development of 3D numerical model for suspended sediment to successfully simulate the transport process of near-bed high concentrated sediment and increase the forecast precision of waterway back-silting quantity, based on the in-depth study of vertical flow structure, and the physical process and parameterization of sediment exchange, with successful application to the dredging and maintenance of the deep waterway at the Yangtze River Estuary. These research findings, both of great significance in estuarine sediment transport theory and waterway engineering practice, have provided theoretical basis and technical support for the design, maintenance, construction and management of deep waterway sediment reducing works at the Yangtze River Estuary. Appraised by the expert panel, the research findings have overall reached the international leading level.