BOUSSINESQ MODEL CALCULATION OF INUNDATION DUE TO TIME-VARYING OVERFLOWING AND WAVE OVERTOPPING ON WHARF

Abstract

 While the typhoon Jebi passed through the Osaka Bay, although flooding on coastal areas was fortunately not occurred, the heavy storm surge caused inundation damage mainly in watersides such as harbor areas due to wave overtopping on quays. At a wharf including the quays, the overtopping water mass flows into the land side and it partially returns to the sea on backwash. Moreover, the situation of wave overtopping can depend on both the tide level and the wave condition varying by the passage of typhoon. In this study, a Boussinesq wave model is improved so that it can calculate flooding on wharves due to wave overtopping continuously, responding to the change of wave and tide level with time. On the calculation reproducing the inundation on the east-side of Rokko Island when typhoon Jebi was passing over, while the calculated inundation heights underestimate the trace heights obtained by site investigation, it is confirmed that the calculated inundation area varies reflecting the history of flooding and discharge on wharves.