東北地方太平洋沖地震津波による宮城県仙台湾南部海岸の海浜変形特性

抄録

We investigate beach morphology change of the Southern Sendai Coast due to 2011 Tsunami by analyzing beach topography before and after the tsunami and aerial video during the tsunami. The results show the characteristics such as erosion at the landward of seawall and landward sediment transport during tsunami runup, seaward sediment transport from shore during backwash, accumulation of sediment around detached breakwaters and T-shaped headland, and beach stabilization by seawall. At the seriously eroded Yamamoto Beach, more than half of the total amount of eroded shore sand above sea level is estimated to be transported seaward and accumulated at a depth of 2 to 15 m. Characteristics of beach morphology change and its mechanisms are demonstrated in this study