Abstract
The meander bends in the alluvial lowlands of the Kitakami, the Oirase, the Gonohe and the Shichinohe Rivers were observed and experiments were made on the work of flowing water using a model flume.
Typical and changeful meander bends appear in the transitional part from alluvial fan to delta In that part flood plains are located between meander scars or between the meander scar and the river channel. The first is point bars changing seasonally, the second is flood plain higher than the point bar transformed only by the high submerged in extraordinarily high water
There are spindle-shaped mounds on the flood plain and point bar, and the form of the mounds are more complicated downstream. The changes are associated with the changes of the meander channels nearby. The upper ends of most meander bends are higher than the lower ends and the outer, sides are higher than inner sides. This lower end functions to discharge overflowing water from inner part. From the result of experiments and observation, it is concluded that these topographies are the products of high water in flood.
