HYDRAULICS IN GRAVEL BED RIVER WITH BOULDERS

Abstract

In steep gravel bed rivers, cobbles and boulders play an important role on stability of the river bed. So we have to consider the resistance of boulders existing on the river bed as well as bed forms in gravel bed rivers. It is important to assess the channel geometry as width and depth formed as a function of flow rate, bed slope and bed materials in gravel bed river. In this study, we used the results of field experiments carried out in the flood plain of the Joganji River. At frrst, we clarified characteristics of the stable bed form in a gravel bed river with boulders. Secondly we estimated frictional and form resistances and bed geometry in gravel bed rivers from observed data.