Abstract
The purpose of this study is to clarify the infiltration mechanism of seawater by wave action in sheltered tidal flat and to quantify infiltration volume of seawater into sediments. We examined the infiltration behavior of seawater by wave and/or tidal action, infiltration velocity as a function of breaking wave height and slope of tidal flat and influence of wave and tidal action on infiltration volume of seawater. The results obtained were as follow:
1) The semi-circular type infiltration of seawater by wave into the saturated sediments was a new phenomenon that was not considered in previous studies on infiltraion mechanism as filling wedge mechanism.
2) The infiltration velocity of seawater was increased with increasing of breaking wave height and slope of tidal flat. However, the effect of the slope was bigger than that of breaking wave height on seawater infiltration into tidal flat sediments.
3) The one, man-made tidal flat, it was estimated that the infiltration volume was 0.072-0.111m3 · m-2 · d-1 by wave and tidal action and 90-94% of its volume was caused by wave action. The other, natural-like man-made tidal flat, it was 0.006-0.008m3 · m-2 · d-1 and 50-63% of its volume was caused by wave action.
