同一水系内ダム群の長期的な治水機能維持を目指した土砂マネジメント手法の検討

Abstract

In Japan it has been difficult to construct new dams because of environmental and financial restrictions. So it is important to maintain existing dams suitably. Especially reservoir sedimentation is one of the most important problems for securing long term functions of dams. It is, therefore, necessary to plan and carry out efficient and economically feasible asset management for existing dam reservoirs. In this study, we focused on long-term effectiveness of reservoir sedimentation management on maintaining flood mitigation functions by several dams in the same river basin. We compared several scenarios based on sedimentation management options and reducing flood risks on the target river sections in the Oyodo River Basin, Miyazaki Prefecture. As the result, we could obtain prioritized reservoir sedimentation management strategy covering all river basin.