ANALYSIS OF SHORELINE BEHAVIOR ON SENDAI COAST BEFORE AND AFTER THE 2011 TSUNAMI

Abstract

The earthquake and tsunami in 2011 caused serious damages on Sendai Coast, Miyagi Prefecture, Japan. Shoreline change characteristics for periods both before and after the tsunami are extracted from processing of aerial photographs together with conducting of Empirical Orthogonal Function (EOF) analysis. The evolution of shoreline at the Nanakita River mouth and the Natori River mouth areas both before and after the tsunami has been discussed. Shoreline change rates at both the river mouths reveal the recovery of morphology but in different aspect, the fast recovery at the Nanakita River mouth while very slow recovery at the Natori River mouth. The results of EOF analysis show that the dominant components of shoreline changes before and after the tsunami are different each other. The dominant component after the tsunami at the two river mouths is also different. The total contribution of the first and the second component is very high in the total contribution of all the components. The contribution of the first component after the tsunami is larger than the first component before the tsunami. The results also show the significant effect of the river mouth on the recovery of the morphology around.