On the Formation of Longitudinal Bed Profiles of Alluvial Rivers

The study focused on the type of river composed of a gravelbed reach with steep slope and a sand-bed reach with mild slope. Supplied sediment to the river during Holocene was investigated by measuring the volume and the grain size of a alluvium. The investigation showed that a gravel supply was much smaller than a sand supply and that the longitudinal profile of a sand-bed reach was almost the same as the equilibrium profile for the sand supply. Through the experiments and 1-D calculation on a alluvial process, mechanisms of the channel formation with the clear longitudinal sorting and the sediment transport mentioned above were estimated.