A Study on the Influence of Submergence Ratio on the Transport of Suspended Sediment in a Partially Vegetated Channel Flow

Abstract

Aquatic or riparian vegetation strongly affects sediment transport in rivers, whose processes affect the relationship between nature and humanity (Västilä & Järvelä, 2018). Accordingly, national strategies or regulations from nations, such as the Ecological protection and high-quality development of the Yellow River (mother river) Basin,

A Numerical Study on the Influence of Riparian Vegetation Patch on the Transportation of Suspended Sediment in a U-Bend Channel Flow

“…As seen in Figure 8c,d, the PDF's level in the vegetated region, 0 < R/Bv < 1, (green subzone) is much less than in the neighboring region, of 1 < R/Bv < 2. This is opposite to that of the partially vegetated straight channel case [9,36]. In the straight channel case, the PDF in the spanwise (radius-wise) mixing layer is clearly smaller than that in the non-vegetated region, because the larger patch-scale eddies deplete particles out of the region [9,36].…”

“…This is opposite to that of the partially vegetated straight channel case [9,36]. In the straight channel case, the PDF in the spanwise (radius-wise) mixing layer is clearly smaller than that in the nonvegetated region, because the larger patch-scale eddies deplete particles out of the region [9,36]. However, the gathering of particles, in the partially vegetated U-bend channel, is still affected by the secondary flow.…”

“…Furthermore, Lelpi et al drew a significant conclusion that the anthropogenic removal of the vegetation cover in the meanders of rivers can speed up the migration rate to an order of magnitude compared to that of a vegetated meander channel [1]. The presence of vegetation plays an essential role not only in the morphology development for the long term but also in the instantaneous suspended sediment dispersion in the short term [8,9]. However, there are a very few investigations on the mechanism of the combined effects of riparian vegetation in bending channels on the dispersion of suspended sediments.…”

Flow Characteristics in Partly Vegetated Channels: An Experimental Investigation

“…Vegetation acts as an obstacle in the flow, causing increased friction and flow resistance which results in reduced flow velocities, increased flow depth, and altered flow patterns [5][6][7][8]. Moreover, vegetation plays an important role in stabilizing riverbanks and preventing erosion [9,10], improving water quality by acting as a natural filter [11], regulating water temperature [12], influencing sediment transport [13,14], providing important habitats for various aquatic organisms [15], and affecting flow structure and turbulence which in turn impact the transport processes and diffusion of dissolved species [16,17].…”

“…In vegetated channels, several properties need to be defined to understand the hydrodynamic flow structures, including flow regime, velocity distribution, vortical structures, turbulence intensities, shear stresses, mixing and dispersion, roughness, vegetation properties, and vegetative drag. Many previous studies have extensively investigated flow dynamics in open channels and their interactions with vegetation canopies [1][2][3][4]14,[16][17][18][19][20][21]. Various approaches, ranging from statistical methods to numerical models, were proposed in the literature to study and understand turbulent flows in vegetated channels.…”