Abstract
By analyzing the detailed water measurement data sets outside/inside of rivers in Tohoku District which were caused by the 2010 Chilean Tsunami, the influences of this tsunami event are estimated. Based on the topographical river mouth, the relationship between river characteristics and tsunami wave height reduction can be derived empirically. This study indicates that the tsunami propagation distance into the river upstream is not only depended on the river mouth geographical features such as river mouth width and depth but also on the tidal level. The larger river entrance, the easier tsunami intrudes. In some narrow and shallow river mouths, the tsunami can only pass through the entrance during the high tide. The empirical relationship between tsunami height and river width has a correlation to the Green's Law
