Yuki OKUYAMA and Takahisa MIZUYAMA
Shutter sabo dams let sediment flow past on typical days; at other times, they retain sediment that may cause trouble downstream. This paper describes the conditions under which shutter sabo dams are applicable. These dams can be used in the bedload transport reaches of most torrents. Fixed]open]type sabo dams are appropriate in torrents where debris flows are infrequent, e. g., once every few decades or longer. In torrents where the ordinary sediment discharge causes problems downstream, closed]type sabo dams should be installed and must be excavated regularly. The operation of the shutters is also discussed. The shutter should be set or closed when new landslides occur or when natural landslide dams form upstream and create sediment discharge that may cause sedimentation problems downstream.
Key wordsFshutter, sabo dam, sediment control, debris flow