Abstract
Saba River passing through Hofu City, Yamaguchi Prefecture has many weirs. Recently, the planning to disuse and integrate weirs has been discussed in order to improve the conveyance ability in Saba River. In this paper, the effect of the removed and built weirs on the river bed elevation change in Saba River is discussed. Firstly, the effect of the flood in 2009 on the river bed materials is studied using the observation data. It is found from the observation data analysis that the mean sediment diameters become smaller than that before the flood in 2009. Secondary, the river bed elevation change for 60 years is studied with the numerical simulations. It is found that it take the river bed elevation at least 8 years to be stable.
