A new model of fine sediment transport for the Fraser river /

The existing models of fine sediment transport assume that the fine sediments behave in the same manner as the coarse-grained sediment and use transport theories developed for the coarse sediment to treat the fine sediment. [...] Among the many differences between the two types of sediments, the most crucial is the difference in the critical condition for initiation and cessation of sediment motion in a flowing medium. [...] In other words, in deposition process of fine sediment, the amount of sediment that would deposit under a particular bed shear stress is a function of the amount of sediment introduced to the system initially, and the fraction of the sediment that would deposit is constant as long as the bed shear stress is held constant. [...] Note that the critical shear stress for erosion is almost two and a half times the critical shear stress for deposition, confirming the earlier result that the fine sediments of the Fraser River behave in a manner similar to that of the cohesive sediment. [...] The sediment quantity coming from the upstream segment will be subjected to the deposition only when the shear stress in the control segment is lower than that in the upstream segment.