Influence of submerged vegetation on flow structure and sediment deposition

被引：3
|
作者：
Sun Z.-L. [1 ]
Zheng J.-Y. [1 ]
Zhu L.-L. [1 ]
Chong L. [1 ]
Liu J. [1 ]
Luo J.-Y. [1 ]
机构：
[1] Ocean College, Zhejiang University, Hangzhou
来源：
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | 2021年 / 55卷 / 01期
关键词：
Sediment deposition; Submerged vegetation; Turbulence intensity; Velocity profile;
D O I：
10.3785/j.issn.1008-973X.2021.01.009
中图分类号：
TQ [化学工业];
学科分类号：
0817 ;
摘要：
Thirty-three sets of flume experiments were conducted under turbid water and submerged vegetation with different arrangements in order to analyze the influence of vegetation on flow structure and sediment deposition. Results showed that the velocity profile was parabola below the canopy of short vegetation while that was logarithmic above it. A bi-Gaussian distribution formula for turbulence intensity in short vegetation zone was established considering plant spacing. The predicted values of velocity and turbulence intensity accorded well with the measured values. Velocity profile is C-type while the largest turbulence is near the canopy in tall vegetation zone. Average velocity below canopy in mixed vegetation with three kinds of plant spacing was 32.5%-72.3% of that without vegetation. The nonlinear relation of relative deposition increment with flow intensity and plant spacing in short vegetation zone was proposed under small Froude number (Fr≤0.18). The deposition in mixed vegetation zone was the largest with 7 times of that without vegetation under the same flow and plant spacing, followed by that in tall vegetation zone. Effects of tall and mixed vegetation on deposition increased with the decrease of plant spacing. Copyright ©2021 Journal of Zhejiang University (Engineering Science). All rights reserved.
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收藏
页码：71 / 80
页数：9
相关论文
共 15 条
  • [1] QU Geng, ZHANG Xiao-feng, CHEN Dong, Et al., Experimental study on flow resistance characteristics in open channel with flexible vegetation, Journal of Hydraulic Engineering, 46, 11, pp. 1344-1351, (2015)
  • [2] HUAI W X, CHEN Z B, HAN J, Et al., Mathematical model for the flow with submerged and emerged rigid vegetation, Journal of Hydrodynamics, 21, 5, pp. 722-729, (2009)
  • [3] WANG Cun, WANG Chao, Turbulent characteristics in open-channel flow with emergent and submerged macrophytes, Advances in Water Science, 21, 6, pp. 816-822, (2010)
  • [4] LIGHTBODY A, NEPF H., Prediction of velocity profiles and longitudinal dispersion in emergent salt marsh vegetation, Limnology and Oceanography, 51, 1, pp. 218-228, (2006)
  • [5] YANG W, CHOI S U., A two-layer approach for depth-limited open-channel flows with submerged vegetation, Journal of Hydraulic Research, 48, 4, pp. 466-475, (2010)
  • [6] KLOPSTRA D, BARNEVELD H J, NOORTWIJK J M, Et al., Analytical model for hydraulic roughness of submerged vegetation, Proceedings of the 27th Congress-International Association for Hydraulic Research, pp. 775-780, (1997)
  • [7] HUTHOFF F, AUGUSTIJN D, HULSCHER S J M H., Analytical solution of the depth-averaged flow velocity in case of submerged rigid cylindrical vegetation, Water Resources Research, 43, 6, (2007)
  • [8] SHI H R, LIANG X R, HUAI W X., Predicting the bulk average velocity of open-channel flow with submerged rigid vegetation, Journal of Hydrology, 572, pp. 213-225, (2019)
  • [9] NEPF H., Flow and transport in regions with aquatic vegetation, Annual Reviews of Fluid Mechanic, 44, pp. 123-142, (2012)
  • [10] SCHULZ M, KOZERSKI H P, PLUNTKE T, Et al., The influence of macrophytes on sedimentation and nutrient retention in the lower river spree (Germany), Water Research, 37, 3, pp. 569-578, (2003)
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