数値計算による瀬戸内海の潮汐·潮流計算と海水交換について

抄録

This paper describes the numerical simulation results of tidal current and water exchange in the Seto Inland Sea. Two kinds of computational conditions were prescribed at the open boundary. One is the simple sinusoidal waves of M₂ component for Case-1, and another is the composite waves by 28 tidal components for Case-2. Then water exchange computations between the Seto Inland Sea water and Pacific Ocean water were carried out by using the computed flow field of Case-1. In this study, following conclusions are obtained. The computed tidal harmonic constants of M₂ component for both cases agree with the observed harmonic constants of M₂ component. Around narrow strait, tidal residual flow of Case-2 is larger than that of Case-1 because of the non-linearity of tidal current. The particles thrown into the computed flow field of Case-2 are more dispersed and transported than those of Case-1 by the influence of the non-linearity of tidal current and tidal residual flow. Comparing the computed salinity distribution with the observed salinity distribution, the case of the diffusion coefficient of 500 m²/s gives the most appropriate result. Using these computed flow field and substance dispersion result, the residence time of the Seto Inland Sea is estimated about 200 days.