CHARACTERISTICS OF WATER LEVEL RISE SPEED BY STORM SURGE AT INNER PART OF YATSUSHIRO BAY AND DISASTER REDUCTION ACTIVITY

Abstract

 The operation of tidal gate constructed in river is difficult when heavy rain is forecasted because flood risk is significant. The delay of operation caused overflow by storm surge in Yatsushiro Bay at August 2015. One of the reason was unexperienced high speed of water level rise. In this study, we analyzed the mechanism of this phenomena and compared to past storm surge events. Then we assessed the variance of water level rise speed from virtual tropical cyclone scenario. Finally, typical tropical cyclone tracks causing high water level rise were selected. Then one viewpoint to assess the possibility of dangerous storm surge event was shown.