The methods of simulating the physical patterns of sediment exchange and bed coarsening and establishing long series river-bed sediment accumulation mathematical model were also given.
in the course of flood running, interaction effect occurs between the flood and river bed, and sediment exchange also occurs between water flow, river bed, flood plain and main channel;
the implementation of the channel project makes the sediment grain size in the project section channel coarser and the sediment grain size in the side shoal area and the downstream of project section finer, which refects the changes in shoal-channel sediment exchange after the implementation of the channel project.
In the suspended sediment field numerical model, the bottom shearing stress is computed to supply the bottom boundary condition and the suspended sediment concentration through aggradations and re-suspension supply the water and sediment exchange.
Based on the basic concept of sediment carrying capacity and the three methods of suspended sediment exchange with bed meterial, the formula of sediment carrying capacity have been obtained under Non-equilibrium and equilibrium conditions in this paper.
Based on a great amount of hydrological and sediment data and the submerged spit evolution analysis, this paper discusses the sediment exchange between the Yangtze Estuary and the Hangzhou Bay and sediment transport along the Nanhui Submerged Spit.
Based on the stochastic mechanistic model of non uniform sediment exchange near the river bed and the probabilistic distribution of fractional transport rate, a new bedload formula for any fraction of non uniform sediment is theoretically developed The parameters are determined from the relations proposed by the authors.
and 4) the secondary Changjiang River plume also plays an important role in the water and sediment exchange between the Changjiang River estuary and the Hangzhou Bay.
The reach downstream of Aishan is the weak link in the flood prevention system of the Lower Yellow River. Since more than thirty years, with an annual sedimentation of 0.1×108t, the total amount of 3.49×108t of sediment has been silted in the reach. The water level at 3000 m3/s has raised by 2.3m for Aishan Station, 2.4m for Luokou Station and 1.2m for Lijing Station. The tremendous sedimentation in this reach mainly occurred in the period from 1964 to 1973, because of concentrated incomin...
Based on the basic concept of sediment carrying capacity and the three methods of suspended sediment exchange with bed meterial, the formula of sediment carrying capacity have been obtained under Non-equilibrium and equilibrium conditions in this paper. The mechanism of Non-equilibrium transport sediment is represented also. The formulas can be widely used in one or two dimensional mathematical models.
his paper concludes the historical achievements in the regulation of the Qiantang estuary over the past 40 years. During this period about 64km unstable channels in the estuarine reach, were tidalbore takes place, have been narrowed and regulated. At the same time about 600 sq.km of tidalflats were reclaimed which has created a great wealth for the country. Nevertheless, the land reclamation along the south bank has pushed the tidal currents to the north bank which erode the sediments under the anc...