Author(s): Asako Takahashi; Yasuharu Watanabe; Yasuhiro Yoshikawa
Linked Author(s): Yasuharu Watanabe
Keywords: No Keywords
Abstract: The Great East Japan Earthquake occurred off the eastern coast of Japan on March 11,2011, triggering a massive tsunami that caused an unprecedented catastrophe in the northeast of the country. Huge waves ran inland up a number of rivers, causing widespread damage to the surrounding areas. Against this background, the authors conducted a field survey on the characteristics of tsunami run-up in eastern Hokkaido with a focus on the observation of an icecovered river in which the surface ice was broken and transported upstream. On this occasion, ice blocks were not transported outside the main channel of the river as they were by the 1952 Tokachi-oki earthquake tsunami, which caused huge damage to nearby residences. The potential damage that can be caused by tsunami running up ice-covered rivers makes it very important to understand the phenomenon. As a first step, the authors sought to clarify differences between tsunami run-up in ice-covered rivers and that in open rivers using a simple one-dimensional numerical simulation model capable of reproducing river ice development. The target of observation was the Ohoro River. Although further consideration regarding the validity of the results obtained is needed because the river in question is small and the effects of the tsunami were not large, it was found that the maximum run-up distance did not vary with the presence or absence of river ice. However, the tsunami wave height in ice-covered sections was found to be greater than that in open sections.
Year: 2012