NUMERICAL SIMULATION OF FLOW FIELD AND SEDIMENT TRANSPORT ON TIDAL FLAT

Abstract

 The Maejima Tombolo Tidal Flat located in Higashihazu-cho, Nishio City, Aichi Prefecture is a tidal flat without rivers to supply sediment. On this tidal flat, seasonal morphological changes and eastward of shallowest part movement of the tidal flat have been confirmed from before. In recent years, this morphological change has been large and it has begun that the characteristics of the change different from previous changes are shown. Local fishermen are concerned about the shrinkage, disappearance and environmental degradation of this tidal flat from now on. The target area repeats drying and submergence by tide. It is difficult to grasp detailed sediment transport and bathymetric change because the number of data acquisition and amount of data are limited only by field observation and analysis. In this study, investigation of the detailed morphological changes on the tidal flat is conducted by using field observation and numerical simulation together. As a result, it was demonstrated that the numerical simulation could mostly reproduce the flow field around the tidal flat. Sediment transport on the tidal flat only in one cycle of a tide was also confirmed by this numerical simulation.