Serious Erosion of the Southern Sendai Coast Due to the 2011 Tohoku Earthquake Tsunami and Its Recovery Process - Post-Tsunami Hazard: Reconstruction and Restoration - page 226

during the tsunami event. Namely, it was clarifi ed that (i) surging tsunami eroded
the land side of the seawalls and transported sediment landward, (ii) land sediment
was accreted in the sea area mainly due to return fl ow during backwash, and (iii)
deposition occurred in the vicinity of the breakwaters and headlands and erosion
due to backwash was suppressed by seawalls. It was estimated that more than half
of the total amount of shore sand above sea level was transported seaward on the
Yamamoto Coast where the erosion was especially severe. In addition to the charac-
teristics of coastal morphology changes and the mechanisms, post tsunami recon-
struction and restoration in the study area are shown. We hope that this study
contributes to further research for disaster reduction, post-disaster restoration, and
conservation of coasts.
In Japan, the Coast Act was established in 1956 to protect coasts from disasters,
and amended in 1999 to also conserve both the coastal environment and utilization.
In the study area, the seawalls are just being reconstructed for disaster prevention.
From the perspective of long-term coastal management, it is strongly required to
fi nd the vision of the future coast to also conserve the coastal environment and
utilization.
Acknowledgments The authors would like to thank Tohoku Regional Bureau for providing
topography data and aerial photographs used in this study. This research was supported by the
Special Project Research of IRIDeS (International Research Institute of Disaster Science), Tohoku
University and by the Environment Research and Technology Development Fund (S-8-1 (4)) of the
Ministry of the Environment, Japan.
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