抄録
A new flood control concept called 'Cascade method' which permits a dam to overflow from an emergency spillway around an upstream region with multiple dams constructed in series in a river basin has been suggested. In this study, mechanism of Cascade method is investigated using dry dams for various inflow flood hydrographs. Cascade method has the following two effects to control flood. First, overflowing at upstream dams in Cascade method suddenly increase each inflow discharge when the water level in the following dam is still not so high. Second, a conventional method in upstream dams performs useless flood control in the second half of a flood. On the other hand, each dam in Cascade method efficiently reduces peak outflow discharge to the design high water discharge in the downstream dam which is the target outflow discharge for the river basin. In Cascade method the second effect is significant compared with the first one.
