Suspended sediment concentration and deformation of riverbed in a frazil jammed reach

The presence of ice in rivers affects hydrodynamic conditions through chang es in both the river's boundary conditions and its thermal regime. Therefor e, the characteristics of sediment transport and the deformation of the riv er channel in ice-covered rivers are quite different from those experiencin g conventional open channel flow. The variables of ice behavior, ice jammin g extent, sediment transport, and deformation of the riverbed during ice pe riods are interrelated on the basis of both physical arguments and field ex periments of river ice jams in the Hequ Reach of the Yellow River. The char acteristics of sediment concentration in water, frazil ice, and ice cover a re described. Analyses have been made on the mechanism of the evolution of frazil jam and the associated adjustments in the riverbed. It has been foun d that the evolution of the ice jam and the deformation of the riverbed rei nforce each other. The interrelationship between the particular features of evolution of ice jam and deformation of riverbed is summarized here in the form of regression relationships relating the hydraulic parameters of wate r under ice jams to the deformation-extent of the riverbed and the jamming- extent.