THE ROLE OF STONES ON THE RIVER BED STABILITY IN STONY BED RIVERS

Abstract

River cross sectional form had settled in the dynamic equilibrium form at the relationship between discharge, the river bed slope and bed material when river improvement is not progressing so much. But, river channels do not seem to satisfy the equilibrium condition of sediment transport due to river improvement work in progress. As the result, many problems have arisen on river management. Sediment transport became discontinuous by the dam and removing large size of bed materials as stones and gravel from rivers is mentioned. In this study, we describe the bed stabilization mechanism of the stony bed rivers found by the field experiment of the Joganji River and the difference in sediment transport mechanism of the stony bed river and the gravel bed river. Moreover, we insist on the problem on washing out of dam reservoir sediment and the necessity for the new bed variation analysis method in the stony bed rivers.