CHARACTERISTICS OF SEDIMENT LOAD AND SHAPE OF ALTERNATIVE BARS WITH DIFFERENT WIDTH-DEPTH RATIO BASED ON FIELD MEASUREMENT OF SEDIMENT LOAD

Abstract

This study aims to clarify the relationships between the sediment load on the alternative bar and width- depth ratio of the bar. Four alternative bars in the Asa and Tone rivers were selected as field measurement sites. In each sites, several sticks and metal rings were installed to observe sediment load. In addition, 35 alternative bars from 7 rivers are investigated to check the relationships between bar morphology and width- depth ratio. As a result, at the area where dense vegetation are grown, the sediment load were less active. Thus, the width that determine the characteristics of alternative bar should be bare land and water surface areas. The width-depth ratio with bare land and water surface areas can represent the characteristics of sediment load on the bar and its shape, which was also confirmed by the two cases of experiments.