Journal of Tropical Oceanography >
Study of the erosion and deposition in a sandbar-lagoon system influenced by submerged vegetation under erosion wave conditions
Copy editor: YAO Yantao
Received date: 2021-06-24
Revised date: 2021-08-31
Online published: 2021-09-06
Supported by
National Natural Science Foundation of China(41976159)
National Key Research and Development Project of China(2019YFC1407900)
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.
CONG Xin , KUANG Cuiping , WU Yunlong , XIA Zilong . Study of the erosion and deposition in a sandbar-lagoon system influenced by submerged vegetation under erosion wave conditions[J]. Journal of Tropical Oceanography, 2022 , 41(4) : 31 -37 . DOI: 10.11978/2021079
表1 工况设计Tab. 1 Design of experimental tests |
工况名称 | 入射波高IWH/m | 波周期/s | 有无植被 | ||
---|---|---|---|---|---|
模型 | 原型 | 模型 | 原型 | ||
T1 | 0.13 | 1.30 | 1.68 | 5.30 | 无(光滩) |
T2 | 0.13 | 1.30 | 1.68 | 5.30 | 有 |
T3 | 0.16 | 1.60 | 1.80 | 5.70 | 无(光滩) |
T4 | 0.16 | 1.60 | 1.80 | 5.70 | 有 |
表2 不同工况下波浪的反射、透射和耗散系数Tab. 2 Wave reflection, transmission and dissipation coefficients |
工况名称 | 反射系数Kr | 透射系数Kt | 耗散系数Kd |
---|---|---|---|
T1 | 0.28 | 0.46 | 0.84 |
T2 | 0.22 | 0.36 | 0.91 |
T3 | 0.36 | 0.48 | 0.80 |
T4 | 0.29 | 0.42 | 0.86 |
表3 最大淤积厚度和最大侵蚀厚度Tab. 3 Maximum deposition thickness and maximum erosion thickness |
位置 | 最大淤积厚度/cm | 最大侵蚀厚度/cm | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
IWH=0.13m | IWH=0.16m | IWH=0.13m | IWH=0.16m | |||||||
T1 | T2 | T3 | T4 | T1 | T2 | T3 | T4 | |||
沙坝 | 5.30 | 6.55 | 6.30 | 6.86 | 13.69 | 12.60 | 16.64 | 14.79 | ||
潟湖 | 7.20 | 5.49 | 6.42 | 6.58 | 0 | 0 | 0 | 0 | ||
前丘 | 7.20 | 5.49 | 6.35 | 6.58 | 14.80 | 13.18 | 15.28 | 13.88 |
表4 沙坝-潟湖系统各区域单宽输沙量Tab. 4 Sediment transporting load per unit width in the sandbar-lagoon system |
单宽输沙量/(cm3·cm-1) | IWH=0.13m | IWH=0.16m | |||||
---|---|---|---|---|---|---|---|
沙坝 | 潟湖 | 前丘 | 沙坝 | 潟湖 | 前丘 | ||
光滩 | 淤积量 | 211.98 | 371.18 | 166.37 | 197.64 | 532.50 | 94.25 |
侵蚀量 | 1393.77 | 0 | 392.93 | 1730.21 | 0 | 404.06 | |
净输沙量 | -1181.79 | 371.18 | -226.56 | -1532.57 | 532.50 | -309.81 | |
总输沙量 | -1037.17 | -1309.88 | |||||
含植被 | 淤积量 | 195.55 | 314.03 | 140.06 | 204.32 | 402.28 | 137.44 |
侵蚀量 | 1216.27 | 0 | 263.48 | 1564.21 | 0 | 329.55 | |
净输沙量 | -1020.72 | 314.03 | -123.42 | -1359.88 | 402.28 | -192.11 | |
总输沙量 | -830.11 | -1149.71 |
[1] |
董凤午, 1981. 沙质海岸岸滩坡度的确定[J]. 水利水运科学研究, (1): 91-102. (in Chinese)
|
[2] |
黄光玮, 丛新, 夏子龙, 等, 2021. 一种挺水植物群砂质动床模型布置方法: 中国, 112681215A[P](in Chinese)
|
[3] |
蒋昌波, 管喆, 陈杰, 等, 2017. 红树林对规则波作用下岸滩剖面变化影响实验研究[J]. 热带海洋学报, 36(1): 95-105.
|
[4] |
邱大洪, 2011. 工程水文学[M]. 4版. 北京: 人民交通出版社: 131 (in Chinese)
|
[5] |
尹硕, 潘毅, 陈永平, 2017. 基于局部拟合法的低能沙质海岸比尺设计[J]. 水利水运工程学报, (4): 43-51.
|
[6] |
|
[7] |
|
[8] |
|
[9] |
|
[10] |
|
[11] |
|
[12] |
|
[13] |
|
[14] |
|
[15] |
|
[16] |
|
[17] |
|
[18] |
|
[19] |
|
[20] |
|
[21] |
|
[22] |
|
/
〈 |
|
〉 |