MODELING OF SEDIMENT TRANSPORT IN ALLUVIAL RIVERS WITH SPUR DYKES

摘要

Sediment transport models are proposed for alluvial rivers with structures such as spur dykes. In order to predict the bed shaping and bed sorting processes more precisely, the total sediment load is subdivided into bed load, suspended load and wash load. In contrast to previous studies, the motion of wash load is accentuated from the perspective of cohesive sediment transport. The river bed made of a mixture of coarse and fine particles, together with slopes in both longitudinal and transverse directions, has also received a special attention. The sediment transport models have been integrated with two hydrodynamic models: a 1D model is designed for the long-term and long-distance processes for the river system, and a 3D k-ε turbulence model has been developed to resolve the local bed variation. The model verification is carried out by application to the field data of the Yodo River system in West Japan and the experimental data of the local scouring around a series of non-submerged spur dykes.