Abstract
The 2011 tsunami flushed sand spit in front of the Nanakita River mouth, Sendai Coast, Miyagi Prefecture. It also caused severe erosion of sand barrier which is adjacent to the left side of the river mouth. These damages formed concave shoreline at this area after the tsunami. The morphological recovery of this area is presented through analysis of aerial photography. The recovery time of morphology is evaluated from analytical solution of one-line model. Results indicate that coastal structures at both ends have major impact on the shoreline evolution. Moreover, the dimensionless recovery time of morphology is depended on the ratio of total length of adjacent sandy coast to the concave width. A new analytical solution of one-line model, which describes the evolution of shoreline of concave landform bounded by rigid boundaries, has been introduced. Good agreement between measured shoreline positions and simulated results is also obtained.
