The offshore waters of the Changjiang Estuary are the transitional areas where river-supplied water and sediment are transported to the sea, and material exchanges occur with the neighbored Hangzhou Bay and the Jiangs...The offshore waters of the Changjiang Estuary are the transitional areas where river-supplied water and sediment are transported to the sea, and material exchanges occur with the neighbored Hangzhou Bay and the Jiangsu waters. Field observations of currents and sediment properties were conducted to study temporal and spatial distributions of suspended sediments under various dynamical conditions. The high sediment concentrations were found to occur in the western and southern waters of the offshore, and the low concentrations occurred in the eastern and northern waters. This pattern of the suspended sediment concentration （SSC） distribution is obviously influ- enced by the runoff and tidal current. The significant difference of along-estuary SSC distribution indicates that the SSC is reduced gradually from the west to the east, and that in the spring tide is obviously higher than in the neap tide. The methods of mechanism analysis and equal-area grids were used to calculate the suspended sediment fluxes at the typical cross sections. It was found that 44 percent of total suspended sediments from the Changjiang River were deposited in the submarine delta, and more than 27 percent of sediments were transported southernly into the Hangzhou Bay, and only 9 percent of sediments was supplied and exchanged with the northern Jiangsu waters, and about 20 percent of sediments was delivered offshore to the sea.展开更多
Sediment convergence and resuspension are the two major mechanisms in forming turbidity maximum (TM) in the Changjiang Estuary. Sediment convergence is mainly controlled by the interaction between runoff and tidal cu...Sediment convergence and resuspension are the two major mechanisms in forming turbidity maximum (TM) in the Changjiang Estuary. Sediment convergence is mainly controlled by the interaction between runoff and tidal current, the mixing of freshwater and salt water, the former forming tidal TM, whereas the latter forming brackish TM. The TM in the Changjiang Estuary is characterized by a combination of tidal TM and brackish TM, which varies temporally and spatially.展开更多
基金The Science and Technology Commission of Shanghai Municipality Point Project under contract No 07DJ14003
文摘The offshore waters of the Changjiang Estuary are the transitional areas where river-supplied water and sediment are transported to the sea, and material exchanges occur with the neighbored Hangzhou Bay and the Jiangsu waters. Field observations of currents and sediment properties were conducted to study temporal and spatial distributions of suspended sediments under various dynamical conditions. The high sediment concentrations were found to occur in the western and southern waters of the offshore, and the low concentrations occurred in the eastern and northern waters. This pattern of the suspended sediment concentration （SSC） distribution is obviously influ- enced by the runoff and tidal current. The significant difference of along-estuary SSC distribution indicates that the SSC is reduced gradually from the west to the east, and that in the spring tide is obviously higher than in the neap tide. The methods of mechanism analysis and equal-area grids were used to calculate the suspended sediment fluxes at the typical cross sections. It was found that 44 percent of total suspended sediments from the Changjiang River were deposited in the submarine delta, and more than 27 percent of sediments were transported southernly into the Hangzhou Bay, and only 9 percent of sediments was supplied and exchanged with the northern Jiangsu waters, and about 20 percent of sediments was delivered offshore to the sea.
基金the National Natural Science Foundation of China under contract! No. 9487005.
文摘Sediment convergence and resuspension are the two major mechanisms in forming turbidity maximum (TM) in the Changjiang Estuary. Sediment convergence is mainly controlled by the interaction between runoff and tidal current, the mixing of freshwater and salt water, the former forming tidal TM, whereas the latter forming brackish TM. The TM in the Changjiang Estuary is characterized by a combination of tidal TM and brackish TM, which varies temporally and spatially.
