Author(s): Jueyi Sui; Bryan Karney; Jun Wang
Linked Author(s): Bryan W. Karney, Jun Wang
Keywords: Sediment concentration; Coarsening; Ice-cover
Abstract: The presence of ice, either as an ice cover or an ice jam in the water, affects hydrodynamic conditions in rivers through changes in both the river boundary conditions and the river’s thermal regime. The important processes of sediment transport and riverbed deformation in ice-covered rivers are therefore quite different from those experienced in conventional open channel flow. This paper discusses the impact of ice cover/jam on the features of sediment transportation based on physical arguments and field investigations at the Hequ gauge station of the Yellow River. Specifically, the features of sediment concentration in water and the grain size distribution are studied. The results show, the suspended load under ice-covered condition is much less than that under open water flow condition. Generally, the sediment concentration during stable ice-covered period is the least, much less than the sediment concentration before river breakup period and during the period immediately after river frozen-up. It is found, for the same cumulative percentage undersize, the suspended load is coarser during ice-covered condition than that under open water condition, although the flow rate is generally quite low under icecovered condition. The analyses show the dependence of sediment concentration on discharge capacity, the extent of riverbed scouring on the extent of ice jam/ice accumulation.
Year: 2004