GENERATION AND PROPAGATION FORECAST OF STORM SURGE IN THE SETO INLAND SEA

The generation and propagation mechanism of storm surge in the Seto Inland Sea was investigated with observed meteorological records, tide records, and numerical analyses. The storm surge from two open boundaries propagates as a free long wave, and harmonizes in the middle of the Inland Sea as an antinode of a standing wave. Furthermore, the storm surge is amplified as a forced long wave by a fast-moving disturbance. If a typhoon passes by quickly or slowly, the astronomical high tide and storm surge peak can overlap somewhere within the Inland Sea. The mean sea level was estimated to rise by -5 cm•kg^-1•m^-3 due to the fresh water of river discharge and rainfall, and inflow of the Pacific water, using observed seawater density. The peak time delay at each tide station from observed storm surge at the Pacific coast was indicated for the storm surge forecast. The peak time delay was well estimated along the northern coast and the middle of the Inland Sea by modeling the moving disturbance of typhoon and the storm surge propagation from two open boundaries.