|Water Science and Engineering 2012, 5(2) 175-190 DOI: 10.3882/j.issn.1674-2370.2012.02.006 ISSN: 1674-2370 CN: 32-1785/TV|
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Experimental research on unstable movements of sandbars under wave actions
Jing YIN*1, Zhi-li ZOU1, Ping DONG2, Hai-fei ZHANG1, Guo-qiang WU1, Yi-nan PAN1
1. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, P. R. China
2. Department of Civil Engineering, School of Engineering, University of Dundee, Dundee DD1 4HN, UK
This study is motivated by recognition of complex sandbar evolution patterns under wave actions inside the surf zone. A series of physical model experiments were conducted in a wave flume to investigate sandbar migration under various wave conditions, including wave groups, regular waves, and random waves. It was observed that under certain wave conditions sandbars move alternately shoreward and seaward rather than continuously in the same direction. The measurements show that the unstable movement of sandbars is closely related to the amplitude modulation of waves. Smaller amplitude modulation tends to produce more intense unstable bar movements. Data analysis further shows that the sandbar migration does not seem to be a passive response of the sea bed to wave forcing, but is most likely caused by the feedback interaction between waves and bed topography.
|Keywords： unstable movement of sandbar sediment transport forced response wave action|
|Received 2011-07-26 Revised 2011-11-09 Online: 2012-06-26|
the National Natural Science Foundation of China (Grant No. 51079024).
|Corresponding Authors: Jing YIN|
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