Development of a meandering channel caused by the planform shape of the river bank
Due to a typhoon and a stationary rain front, record amounts of rain fell in September 2011, and the largest class of discharge in recorded history was observed in the Otofuke River of eastern Hokkaido in Japan, and extensive bank erosion occurred in various parts of the river channel. Damages were...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2014-04-01
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Series: | Earth Surface Dynamics |
Online Access: | http://www.earth-surf-dynam.net/2/255/2014/esurf-2-255-2014.pdf |
Summary: | Due to a typhoon and a stationary rain front, record amounts of rain fell in
September 2011, and the largest class of discharge in recorded history was
observed in the Otofuke River of eastern Hokkaido in Japan, and extensive
bank erosion occurred in various parts of the river channel. Damages were
especially serious in the middle reaches, where part of a dike was washed
out. The results of a post-flood survey suggested that the direct cause of
the dike breach was lateral advance of the bank erosion associated with the
development of meandering channels. As the related development mechanism and
predominant factors have not yet been clarified, this remains a priority from
the viewpoint of disaster prevention. A past study on the development of
meandering channels was reported by Shimizu et al. (1996). In this study, the
meandering channel development process was reproduced using a slope failure
model that linked bank erosion with bed changes. The study attempted to
clarify the meandering development mechanism in the disaster and its
predominant factors by using this model. The analysis properly reproduced the
characteristics of the post-flood meandering waveforms. Therefore, it is
suggested that the development of meandering during the flood attributed to
the propagation of meandering downstream, which is triggered by the
meandering flow from the meandering channel in the upstream, which also
suggests that this propagated meandering then caused a gradual increase of
meandering amplitude accompanied by bank erosion in the recession period of
the flood. |
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ISSN: | 2196-6311 2196-632X |