1996 Volume 40 Pages 199-204
Without sediment supply from the upstream, the river is suffered by the so-called rotational degradation during flood. When the river is bordered by vegetation zone, the flow near the vegetated zone is retarded and the bed degradation is limited to the central zone. Then, during the period with small discharge after flood, some part of the width becomes dry, and it often allows the vegetated zone to invade there. On the next flood, the flow concentrates to the center zone more by the growth of vegetated zone and the degradation becomes severer. Such a process is discussed in a simple scheme experimentally and theoretically.
