急流都市河川豊平川における河道内構造物の維持管理および植生管理に関する検討-平成23年9月出水を受けて-

抄録

Compound channel with a series of vertical groundsills in low water channel is popular countermeasure for flood and sediment control works in Japan, especially instep slope rivers. The main river flowing through the city of Sapporo, Toyohira River, has 7 groundsills in low water bed．The river environments of Toyohira River have been changed in recently. For example, the number of riparian trees has been increasing in low water channel and the bed degradation has been going on rapidly. The changes of the river environment give various problems from the point of view of operation and maintenance, especially for groundsills in low water channel in Toyohira River. In this study, we performed numerical simulations of flow and bed deformation with the groundsills and riparian trees in Toyohira River during the flood in September 2011. The results showed clearly the effect of the groundsills and riparian trees for the balance of sediment transport in low water channel in Toyohira River.