Numerical Study of Topographic Changes of Intertidal Flat due to Tidal and Coastal Currents

Abstract

A three-dimensional numerical model to simulate the topographic change of intertidal flats of sand and cohesive sediments like mud due to tidal and coastal currents was applied to the field of the Shirakawa Intertidal Flat in the Ariake Sea. Numerical results showed good agreements qualitatively with observed results with regard to topographic changes around the mouth of river. They also showed that the simultaneous calculation of tidal and coastal currents including the wave-current interaction and the consideration of mud content were very important to simulate the topographic change of intertidal flats. Finaly, the sediment budget around the mouth of river were calculated and the results showed almost good agreements with the estimation by using filed data. These results show the validity of this model to calculate sediment transports and topographic changes of the intertidal flat.