BEACH MORPHOLOGICAL CHANGES ON SENDAI COAST BY TYPHOON LIONROCK

Yuta Mitobe,Makoto Umeda,Hitoshi Tanaka,Akihiro Suzuki,Daisuke Komori,Yoshiya Touge

doi:10.9753/icce.v36.sediment.34

Yuta Mitobe, Makoto Umeda + Show 4 more

Open Access

https://doi.org/10.9753/icce.v36.sediment.34

Copy DOI

Abstract

In 2016, a few typhoons attacked Tohoku Area of Japan, and one of them, named Typhoon Lionrock, approached and hit Tohoku Area from the Pacific Coast, which is the first observed typhoon to have such a course in the observation history of Japan. In order to know magnitude of the storm surge and high waves induced by the typhoon and their influence on the coastal area, field surveys were conducted on the day of the typhoon arrival and also the next day. The target of the survey was Sendai Coast, which is a part of the Pacific Coast of Tohoku Area. The coast was severely affected by the 2011 Great East Japan Earthquake Tsunami, and its effect on the beach morphology still remains according to shoreline change analysis with aerial photographs by Hoang et al. (2016). In this paper, the shoreline changes by and after the typhoon were analyzed with the aerial photographs taken in every one or two months to understand its effect on the beach processes. And the results were combined with the shoreline data after the 2011 tsunami to see the impact of the typhoon on the beach processes under the recovery from the tsunami event.

Highlights

In 2016, a few typhoons attacked Tohoku Area of Japan, and one of them, named Typhoon Lionrock, approached and hit Tohoku Area from the Pacific Coast, which is the first observed typhoon to have such a course in the observation history of Japan
FIELD SURVEY Based on observation soon after the typhoon and the level of the debris deposited by high waves, the maximum run up height was estimated as approximately 4 m from the mean sea level
Predominant direction of longshore sediment transport is northward, and it was partly blocked by the river flow (Pradjoko and Tanaka, 2010)

Summary

Introduction

In 2016, a few typhoons attacked Tohoku Area of Japan, and one of them, named Typhoon Lionrock, approached and hit Tohoku Area from the Pacific Coast, which is the first observed typhoon to have such a course in the observation history of Japan. FIELD SURVEY Based on observation soon after the typhoon and the level of the debris deposited by high waves, the maximum run up height was estimated as approximately 4 m from the mean sea level. It is enough lower than the height of coastal dykes; about 5 m from MSL before the 2011 tsunami and 7 m currently.

Results

Conclusion