筑後川の旧蛇行部と支川流入による治水と利水への効果の検討

抄録

Chikugo River has a catchment area of 2,860km², a trunk length of 143km, and a tidal reach of 23km. In Chikugo River basin, damages due to floods frequently occurred. As a result, many cut-off channels were constructed to increase the capacity of flow rate of Chikugo River. After constructions of these cut-off channels, the old meandering waterways are still existing. Moreover, inflowing tributaries to the old meandering part of Chikugo River are not flowing into Chikugo River directly but they are once flowing into the old meandering waterway of Chikugo River.

In this study, we conducted a one-dimensional unsteady flow analysis and a two-dimensional inundation analysis in the downstream basin of Chikugo River including the old meandering waterway of Chikugo River and inflowing tributaries to clarify their functions with respect to the flood control and water utilization.