The study focused on understanding how changes in sediment size affect sediment transport in the Kurobe sediment flow system. By identifying the effective grain size ranges, researchers aimed to improve sediment management in the area. They found that certain grain sizes can cause shifts in sediment transport, leading to issues like sedimentation in dams and erosion of river beds and beaches. This study helps pinpoint the key grain sizes that influence sediment movement, which is crucial for managing sediment effectively in the Kurobe system.