| Although the basic mechanisms of sediment transport in sewers are the same as in rivers, it is not necessarily appropriate to use the many mode1s that have been developed for sediment transport in rivers also in sewers. Different reasons are: 1) sewer sediments are often mixtures of cohesive and non cohesive material, and the bed is often stratified: 2) due to consolidation of the (partly cohesive) bed material, the erosion resistance of the bed may vary with time; 3) the flow conditions in sewers are usually unsteady, which is not accounted for in the classical sediment transport mode1s; 4) existing models have been derived from experiments in rectangu1ar flumes: the results are not directly applicable to sewers with circular cross section where the... |
