Abstract
Tsunami caused by 2011 Great East Japan Earthquake gave enormous damage to the plains where countermeasures against huge tsunami disaster was not done. In order to clarify the tsunami mitigation effect of coastal dune and fill, in this study, we surveyed inundation depth and structural damage in Asahi City, Chiba Prefecture and Natori City, Miyagi Prefecture. The results showed that coastal dune in which the height were comparable to tsunami height, decreased the inundation depth and structural damage in the hinterland of the dune. It means that the coastal dune and fill can be an effective countermeasure for tsunami disaster in the plains with sandy beach. These results were dominant in Asahi City with the coastal dune with the length more than 3km along the coastline.
