Storm surge simulation in Nagasaki during the passage of 2012 Typhoon Sanba

As a result of global warming effect, storm surges generated by extreme weather events such as tropical cyclones, typhoons and hurricanes, significantly impact to the life and property in storm-surge prone coastal low-lying areas. Therefore, numerical modeling systems, comprising meteorological, hydrodynamic and wave simulation capabilities are essential for the storm surge hindcasting and forecasting phases in disaster mitigation and management processes. Accordingly, we assessed the applicability of two meteorological simulation methods; (1) Mesoscale Meteorological Model MM5 and (2) Delft Dashboard (DDB) Tropical Cyclone Tool, together with DelftBD FLOW-WAVE coupled modeling system to simulate the storm surges in Nagasaki coast during the passage of 2012 typhoon SANBA. Storm surge generated by MM5-Delft3D and DDB-Delft3D systems in Nagasaki area were reasonably agreed with the observations. Thus, applicability of both meteorological simulation techniques together with Delft3D FLOW-WAVE coupled modeling system to simulate the storm surge was validated with a reasonable level of accuracy. Further, compared to the MM5-Delft3D system, fast and easy simulation capability of DDB-Delft3D system was identified. However, in terms of accuracy, MM5-Delft3D system demonstrated much better performance in outer regions of the typhoon than the DDB-Delft3D system.