2019 Volume 75 Issue 2 Pages I_343-I_348
In this study, movable bed experiments on topography change caused by large-scale tsunami eddy were implemented to understand the influence of the grain size ratio of bed material on the topography change. Measurements were performed changing the mixing ratio of sand with two kinds of grain sizes.
The experimental results revealed that the amount of topography change is different depending on the grain size although the difference of the grain size has little influence on the spatial distribution of the erosion and deposition. It was also found that the smaller the content rate of coarse sand is, the larger the amount of topography change is. The results implied that the topography change for mixed grain size sand could be estimated by conducting linear superposition of the amount of topography change for each single-size sand based on the mixing ratio of sand. Coarse sand was confirmed to tend to deposit in the area where deposition occurs near sediment sources.