Premium
Stochastic Simulation of the Suspended Sediment Deposition in the Channel With Vegetation and Its Relevance to Turbulent Kinetic Energy
Author(s) -
Yang Liu,
Huai Wenxin,
Guo Yakun
Publication year - 2021
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2021wr030380
Subject(s) - deposition (geology) , turbulence kinetic energy , turbulence , sediment , vegetation (pathology) , hydrology (agriculture) , flow (mathematics) , geology , environmental science , kinetic energy , soil science , geomorphology , mechanics , geotechnical engineering , physics , medicine , pathology , quantum mechanics
The aquatic vegetation patch plays a significant role on sediment net deposition in the vegetated channels. Particularly, the flow is decelerated at the leading edge of a patch that tends to induce vertical updraft, that is, a diverging flow region, in which vegetation greatly affects the pattern of sediment net deposition. This study focuses on the simulation of the sediment net deposition in the whole vegetation patch region through an innovative random displacement model, a Lagrange method, with probability‐based boundary conditions, instead of the reflection or sorption boundary at the channel bottom. The probability model of deposition and resuspension is proposed according to the flow field characteristics in the different regions of the vegetation patch. The variation of the sediment deposition and resuspension with the turbulent kinetic energy is analyzed to illustrate the effect of the turbulence induced by vegetation, represented by the dimensionless turbulent kinetic energy ( ψ ), on the sediment deposition and resuspension. The sediment deposition predicted by the proposed model agrees well with the experimental measurements. Results show that the effect of vegetation on the sediment deposition and resuspension motions begins to prevail when the vegetation‐induced ψ is larger than its threshold, ψ * . The threshold of ψ is predicted to be within 6.8–10 according to the simulation results in this study. As the turbulent kinetic energy increases, the deposition probability decreases continuously when ψ > ψ * .