Abstract
A new flood control concept called ’Cascade method’ which permits multiple dams around an upstream region in a river basin to overflow from their emergency spillways has been suggested. In this study, Cascade method was compared with a conventional flood control method under conditions that multiple dry dams have the same reservoir capacity in order to understand the flood control mechanism of Cascade method. In the conventional method, upstream dams transform flood hydrograph horizontally and remain its peak partially at an end of the flood. Therefore, a downstream dam has to function again in order to reduce the remained peak. On the other hand, multiple dams in Cascade method transform the hydrograph vertically and reduce its peak linearly. In addition, empirical formulas were established to estimate quantitatively the flood control capability of multiple dry dams constructed in series in Cascade method.
