THE EFFECTS OF RIVER BED GRAIN SIZE DISTRIBUTION AND GROUND SILL ON SEDIMENT DYNAMICS – A CASE STUDY OF MIDAIGAWA RIVER AND OOMUKAWA RIVER

Abstract

Understanding to sediment dynamics, especially in upstream, is not sufficient to precisely estimate amount and component of bed load. In this paper, two tributaries - Midaigawa River and Oomukawa River - having the same scale in high-sediment-producing Fujikawa River basin are compared. Flume experiment is held to clarify characteristics of mixed sand and influences of continuous drop structures. Thereafter how alluvial procedure determines riverbed materials and results to differences in grain size distribution is identified.