Damage to Seisho Bypass due to Storm Waves During Typhoon 0709
Takaaki Uda*, Toshiro San-nami**, and Toshinori Ishikawa*
*Public Works Research Center, 1-6-4 Taito, Taito, Tokyo 110-0016, Japan
**Coastal Engineering Laboratory Co., Ltd., 301, 1-22 Wakaba, Shinjuku, Tokyo 160-0011, Japan
Some 1.1 km of the Seisho Bypass along the Seisho coast was severely damaged on September 7, 2007, due to Typhoon 0709 storm waves, closing the road to traffic for emergency repairs. Damage to the highway, caused primarily through wave impact and secondarily by long-term shoreline recession due to decreased fluvial sand supply from the Sakawa River and sand loss into a submarine canyon, was investigated through field observations. A factor contributing further to shoreline recession was the obstruction of eastward longshore sand transport by the Ninomiya fishing port breakwater. Storm waves hit the coastline counterclockwise to normal to the shoreline, causing offshore and westward longshore sand transport with part of the sand transported by the longshore sand transport flowing into the submarine canyon, causing a net sand loss.
-  P. D. Komar, “Beach Processes and Sedimentation,” Second Edition, New Jersey, Prentice-Hall, pp. 544, 1998.
-  H. Mase, “Multidirectional random wave transformation model based on energy balance equation,” Coastal Eng. Jour., JSCE, Vol.43, No.4, pp.317-337, 2001.
-  T. Uda, “Beach erosion in Japan,” Sankaido Press, pp. 442, 1997 (in Japanese).
-  T. Uda, “Beach erosion arising from artificial land modification,” Jour. Disaster Res., Vol.2, No.1, pp. 29-36, 2007.
-  T. Uda and T. Ishikawa “Method of practical site observation for facilitating understanding of a coast,” Asian and Pacific Coasts 2007, Proc. 4th Int. Conf., pp. 1479-1489, 2007.
-  T. Uda, Y. Hoshigami, S. Seino, and H. Ozawa “Increase in disaster potential caused by excess use of land in coastal zone,” Jour. Coastal Res., SI 50 (Proc. 9th International Coastal Symposium), Gold Coast, Australia, pp. 140-146, 2007.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 International License.