Abstract
Recently, the tidal flats were constructed each place. However, it has been reported that the bottom topography and the sediment size were not stable after the construction due to the wave action. In order to analyze the property of bottom topography and sediment size, it was studied by hydraulic model test and field survey. As a result of model test, it was shown that topography shape and the sediment size changed in conjunction with a wave condition, i.e. erosion / coarse grain at the time of high waves, accretion / fine grain at the time of regular waves. The topography of the constructed tidal flat which was constructed by muddy dredged sediment in Ago Bay also changed with the same property as the result of the hydraulic model test, but the sediment size changed contrary finely.
