Abstract
The purpose of this paper is to study the effect of dam construction on the middle reaches of alluvial rivers. The Nibutani dam was constructed on the Saru River, 21.4km upstream of its mouth in 1996. In this paper, the flow and sediment transport system is studied along the Saru River including field resoluts from the Nibutani dam and its reservoir. The sediment transport rate, bed material distribution, and bed elevation changes were investigated before, after and during a flood. A numerical model to predict the sediment transport rate and river bed changes are proposed and verified using the data obtained by field measurements. This study clarifies the effect of the dam on the river, and many useful information for river and dam management works are obtained.
