抄録
In Kurobe sediment flow system, several problems have been caused by change in the sediment balance, such as sedimentation in dam, river bed degradations, beach erosions and etc.. It has been necessary to resolve these problems and improve the sediment transport by the sediment management. In order to promote the sediment management, it is important to study sediment balance within effective grain size ranges and to know a grain size range which causes the change of sediment transport. In this study, the effective grain size ranges is fixed in Kurobe sediment flow system, and the causes of the change of the sediment transport and issues of sediment management are confirmed in view of the sediment balance within the effective grain size ranges.