Journal of Tropical Oceanography ›› 2022, Vol. 41 ›› Issue (4): 31-37.doi: 10.11978/2021079CSTR: 32234.14.2021079

• Marine geomorphology • Previous Articles     Next Articles

Study of the erosion and deposition in a sandbar-lagoon system influenced by submerged vegetation under erosion wave conditions

CONG Xin(), KUANG Cuiping(), WU Yunlong, XIA Zilong   

  1. Tongji University, Shanghai 200092, China
  • Received:2021-06-24 Revised:2021-08-31 Online:2022-07-10 Published:2021-09-06
  • Contact: KUANG Cuiping E-mail:congxin1992@foxmail.com;cpkuang@tongji.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41976159);National Key Research and Development Project of China(2019YFC1407900)

Abstract:

Global coastal ecological system is being threatened by climate change and human activities. Based on a typical profile of sandbar-lagoon system and designed wave flume experiments with moving bed, we carried out a quantitative analysis on the effects of submerged vegetation on erosion and deposition under erosion wave conditions. The results show that the submerged vegetation obviously weakens the wave height that increaes in the margin of surf zone on the fore slope of sandbar, and wave attenuation occurs behind the sandbar. Wave reflection and transmission coefficients reduce and wave dissipation coefficient increases due to submerged vegetation. Under the action of erosion waves, the sandbar crest was eroded distinctly, the lagoon showed a deposition trend, and the coastal foredune was eroded in a scarp form. With the influence of vegetation, the maximum erosion thickness of sandbar and foredune zone decreases. In general, vegetation can reduce the net sandbar erosion, the deposition in the lagoon and the offshore sediment transport, which has a good protective effect on the coastal foredune.

Key words: erosion wave, submerged vegetation, sandbar-lagoon, erosion and deposition, wave attenuation

CLC Number: 

  • P737.13