Numerical Model for Flow Motion with Vegetation

Zhang, Jiantao; Su, Xiaohui

doi:10.1016/s1001-6058(08)60043-8

Cited by 25 publications

(10 citation statements)

References 11 publications

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“…Some approaches take into account the interactions between high velocity regions in the mainstream and slow velocity regions in the vegetated regions. In this context, Zhang and Su (2008) proposed three equations to determine appropriate drag coeffi cients in laminar, laminarturbulent and fully turbulent fl ow regimes.…”

Section: Theoretical Aspects Of Vegetated Fi Ltersmentioning

confidence: 99%

Vegetated filter effects on sedimentological connectivity of agricultural catchments in erosion modelling: a review

Gumière

Bissonnais

Raclot

et al. 2010

Earth Surf Processes Landf

114

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The sedimentological connectivity of agricultural catchments may be affected by anthropogenic structures (land management practices) established to reduce sediment exportation from agricultural plots to water streams. Distributed erosion models may in theory provide information about where and how these structures should be installed in catchments to reduce sediment exportation. The interaction between sediment exportation and land management practices is very complex from both theoretical and experimental points of view. Vegetated fi lters are a widely used land management practice. They interact with water fl ow, change turbulence conditions, and ultimately affect sediment transport and deposition processes. Experimental results have shown that the effi ciency of sediment trapping in vegetated fi lters is infl uenced by fl ow characteristics, sediment size, and vegetation type, as well as by the slope and width of the fi lter in the streamwise direction. At the catchment scale, the spatial organisation of management practices is crucial for the global sedimentological connectivity. Present-day erosion models propose different approaches to simulate the infl uence of management practices on soil loss and sediment export for agricultural catchments. Some of them use the Sediment Delivery Ratio (SDR) or P-factor to describe sediment transport from source to sink areas. Others, such as in the TRAVA and VSFMOD, rely on process-based descriptions involving changes in roughness and infi ltrability along fl ow paths to study the effect of management practices. From the literature review conducted herein, we identifi ed the lack of an approach of intermediate complexity, that would be more physically relevant than SDR and P-factor approaches, but simpler and easier to spatialise than TRAVA and VSFMOD-type models.

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Section: Theoretical Aspects Of Vegetated Fi Ltersmentioning

confidence: 99%

Vegetated filter effects on sedimentological connectivity of agricultural catchments in erosion modelling: a review

Gumière

Bissonnais

Raclot

et al. 2010

Earth Surf Processes Landf

114

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“…Vegetation can inhibit sediment suspension, purify the water environment, prevent water flow from eroding riverbanks, and have great practical value in maintaining the ecological function stability of river systems ( Kemp et al., 2000 ; Wu et al., 2007 ; Nept, 2012 ; Aberle and Järvelä, 2013 ; Boothroyd et al., 2017 ). However, the existence of vegetation changes the flow characteristics of the channel, affects the flow velocity and turbulence characteristics, and changes the relationship between the storage and discharge of the channel, thereby changing the process of river confluence ( Zhang and Su, 2008 ; Rominger and Nepf, 2011 ; Velísková et al., 2017 ), which has a non-negligible impact on the advancement of river flow, especially flood runoff in flood season ( Mulahasan and Stoesser, 2017 ; Nosrati et al., 2022 ).…”

Section: Introductionmentioning

confidence: 99%

Flow characteristics of open channels based on patch distribution of partially discontinuous rigid combined vegetation

Zhang

Wang

et al. 2022

Front. Plant Sci.

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To clarify the flow characteristics of open channels under the combined distribution of vegetation in a patch, this study used the computational fluid dynamics tool FLUENT and the Reynolds stress model to design four combined and four discrete distribution modes under two different inundation states (submerged and non-submerged). The flow characteristics of longitudinally discontinuous rigid vegetation patches occupying half the width of the channel were numerically simulated. The numerical model is verified by indoor open channel flume experiments, and the obtained model data is in good agreement with the measured data. The results showed that: 1) The diameter of vegetation is an important factor affecting the wake structure. Under the submerged condition. 2)The submerged state, distribution pattern and combination form of vegetation are important factors that affect the distribution of flow velocity and change the structure of water flow. That is, the influence of vegetation distribution pattern on flow velocity and turbulence intensity under submerged condition is significantly weaker than that under non-submerged condition, and the flow velocity in non-vegetation area is significantly higher than that in vegetation area. The increase in the combined vegetation comprehensive stem thickness and the discrete degree resulted in an increase in the difference in flow velocity and turbulence intensity. 3) As the water flowed downstream, the flow velocity along the vegetated area continuously decreased, while it increased continuously along the non-vegetated area, and the difference in flow velocity between the two areas became more apparent. 4) The inundation state and combination characteristics of vegetation were important factors affecting the Reynolds stress of the channel location in the patch area.

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“…Most works consider artificial vegetation, and the plants are simplified as cylinders (e.g. Zhang and Su, 2008); determination of frontal area is thus quite straightforward. However, this is not the case when natural vegetation is to be considered either in the laboratory or field.…”

Section: Introductionmentioning

confidence: 99%

“…Pedras and de Lemos (2003) reported that their study on modelling turbulent flow through porous media could be applied to natural systems such as forest and vegetation. Zhang and Su (2008) derived a mathematical model for turbulent flow in a vegetated channel by utilising the vegetation porosity parameter, given by…”

Section: Introductionmentioning

confidence: 99%

Estimation of vegetation porosity in vegetated waterways

Montakhab¹,

Yusuf²,

Ghazali³

et al. 2013

Proceedings of the Institution of Civil Engineers - Water Manag

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Vegetation porosity in a vegetated channel has been identified as the main parameter that contributes to the flow behaviour and resistance in the channel. Estimation of vegetation porosity is quite a challenging task due to the diverse characteristics of vegetation. In this study, several porosity measurement methods based on vegetation frontal area and vegetation volume were used to estimate the porosity of vegetation (Lepironia articulata) in a laboratory flume for various flow and vegetation characteristics. Digital image analysis was one of the methods used to estimate porosity. The study also involved measurements of velocity using a three-dimensional acoustic Doppler velocimeter and flow depths at different spatial locations along the flume. The volumetric method for porosity measurement, which considers the fraction of the actual volume of the vegetation to the volume of water, is considered more practical and accurate than the other methods that were studied. The results of this study indicate that, by assuming vegetation to be cylindrical in shape and considering only the frontal area of the most upstream vegetation, porosity could be underestimated by 14%. Digital image analysis gave a difference of only 5%. From the laboratory data, correlations between the mean velocity, water depth and vegetation porosity were established. It was observed that by reducing the vegetation porosity by 8%, the velocity could reduce by between 35-60% depending on flow rate.

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Numerical Model for Flow Motion with Vegetation

Cited by 25 publications

References 11 publications

Vegetated filter effects on sedimentological connectivity of agricultural catchments in erosion modelling: a review

Vegetated filter effects on sedimentological connectivity of agricultural catchments in erosion modelling: a review

Flow characteristics of open channels based on patch distribution of partially discontinuous rigid combined vegetation

Estimation of vegetation porosity in vegetated waterways

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