Recently, the sea level rise due to global warming is apprehensive, and the sea level rise increases vulnerability to inundation in coastal areas due to storm surges and tsunamis. A flap gate is useful as one countermeasure against the storm surges and tsunamis. We are performing the studies for design and construction by considering the hydraulic and hydrodynamic characteristics for the new type flap gate. This paper presents the results derived by the hydraulic model tests using the 2-dimennsional channel with a wave maker and the model of scale 1: 35, in order to investigate the characteristics of the gate behavior during rise and sink and the floodgate effects on hydrodynamics given by various conditions of wave motion and tidal movement.
