Author(s): Satomi Yamaguchi, Ryosuke Akahori, Hiroki Yabe
Linked Author(s): Satomi Yamaguchi
Keywords: Riverbed form, flow resistance, bedform observation, the Toyohira River, bedform evolution
Abstract: Small-scale riverbed forms enhance form resistance against channel flow and greatly affect a rising water level during flood, so it is quite important to comprehend changes in riverbed topography from the standpoint of river disaster prevention. Further, form resistance decreases tractive force, which greatly influences sediment movement during flood. Thus, the comprehension of riverbed topography during flood is all the more crucial in order to foresee inundated sediment movement. However, few studies have investigated the relation between small-scale riverbed forms and their form resistance on the basis of actual riverbed observation data because riverbed forms are difficult to measure during flood. In this study, the riverbed topography in the lower reach of the Toyohira River is investigated through the observation method proposed by the authors, with the aim of grasping the characteristics of riverbed forms during flood. Small-scale riverbed forms which developed during a relatively large-scale flood is observed and commensurate form resistance is examined
Year: 2017