Effect of staggered and square arrangements on surface shear stress and sand transport rate on tree vegetated surface

doi:10.7522/j.issn.1000-694X.2023.00074

Journal of Desert Research ›› 2024, Vol. 44 ›› Issue (1): 50-60.DOI: 10.7522/j.issn.1000-694X.2023.00074

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Effect of staggered and square arrangements on surface shear stress and sand transport rate on tree vegetated surface

Meng Zhang(), Liqiang Kang(), Xiaomei Wang

State Key Laboratory of Earth Surface Processes and Resource Ecology / Engineering Center of Desertification and Blown-Sand Control of Ministry of Education，Faculty of Geographical Science，Beijing Normal University，Beijing 100875，China

Received:2023-03-28 Revised:2023-05-16 Online:2024-01-20 Published:2023-12-26
Contact: Liqiang Kang

Abstract

Abstract:

Vegetation arrangement is an important factor affecting the wind shear action on the surface， and then affects the sand-proof effect. In this paper， the surface shear stress distribution， total shear stress and sand transport rate of rigid tree models in staggered and square arrangements are measured in wind tunnel， and the differences between the two arrangements are analyzed. The results show that under three plant densities （18， 32， 50 plants·m^-2）， the average surface shear stress in staggered arrangement is 8.5%-11.9%， 13.8%-16.5%， 15.3%-17.2% lower than that in square arrangement， respectively. In the shear-stress partitioning model， the parameter β of staggered arrangement （mean=220） is larger than that of square arrangement （mean=180）， while the parameter m of the two arrangements is very close. Under the same incoming wind speed and plant density， the sand transport rate in staggered arrangement is lower than that in square arrangement with an average reduction of 24%. However， the variation of sand transport rate with the average surface friction velocity is not affected by arrangement. The results of this paper are helpful to understand the role of vegetation arrangement in wind erosion control from the perspective of surface shear stress.

Key words: surface shear stress, sand transport rate, arrangement mode, tree model, wind tunnel tests

CLC Number:

X169

Meng Zhang, Liqiang Kang, Xiaomei Wang. Effect of staggered and square arrangements on surface shear stress and sand transport rate on tree vegetated surface[J]. Journal of Desert Research, 2024, 44(1): 50-60.

Figures/Tables 16

Fig.1 Wind speed profiles in wind tunnel

Fig.2 Rigid plastic plant model （h0=9 cm， σ=0.01）

Fig.3 Sketch of plant positions in staggered （A） and square （B） arrangements （32 plants per square meter）

Table 1 The row spacing and plant spacing under different plant densities and arrangements

排列方式	植株密度/（株·m^-2）	行距/m	株距/m
交错	18	0.167	0.333
	32	0.125	0.250
	50	0.100	0.200
矩形	18	0.236	0.236
	32	0.177	0.177
	50	0.141	0.141

Fig.4 Measurement system of surface shear stress （A） and total shear stress （B）

Fig.5 Measurement points of surface shear stress in staggered （A） and square （B） arrangements （air flows from left to right）

Fig.6 Comparison of surface shear stress distribution between staggered （A， C， E） and square （B， D， F） arrangements in different plant densities （the black dot is the position of plant model， uf0 is the incoming wind speed， τs is the surface shear stress）

Fig.7 Variation of average surface shear stress （τs'） with incoming wind speed in staggered and square arrangements

Table 2 Ratios of average surface shear stress， shear stress acting on roughness elements and total shear stress in staggered array to that in square array

植株密度 /(株·m^-2)	u_f0 /(m·s^-1)	$τ s, 交错' τ s, 矩形'$	$τ R, 交错 τ R, 矩形$	$τ 交错 τ 矩形$
18	8.0	0.915	1.035	1.017
	9.3	0.899	1.038	1.017
	10.8	0.902	1.037	1.018
	12.2	0.903	1.037	1.018
	13.6	0.881	1.040	1.017
32	8.0	0.862	1.071	1.050
	9.3	0.844	1.064	1.042
	10.8	0.836	1.055	1.035
	12.2	0.839	1.049	1.029
	13.6	0.835	1.043	1.024
50	8.0	0.828	1.101	1.081
	9.3	0.833	1.102	1.083
	10.8	0.846	1.103	1.086
	12.2	0.835	1.105	1.088
	13.6	0.847	1.105	1.089

Table 2 Ratios of average surface shear stress， shear stress acting on roughness elements and total shear stress in staggered array to that in square array

植株密度 /(株·m^-2)	u_f0 /(m·s^-1)	$τ s, 交错' τ s, 矩形'$	$τ R, 交错 τ R, 矩形$	$τ 交错 τ 矩形$
18	8.0	0.915	1.035	1.017
	9.3	0.899	1.038	1.017
	10.8	0.902	1.037	1.018
	12.2	0.903	1.037	1.018
	13.6	0.881	1.040	1.017
32	8.0	0.862	1.071	1.050
	9.3	0.844	1.064	1.042
	10.8	0.836	1.055	1.035
	12.2	0.839	1.049	1.029
	13.6	0.835	1.043	1.024
50	8.0	0.828	1.101	1.081
	9.3	0.833	1.102	1.083
	10.8	0.846	1.103	1.086
	12.2	0.835	1.105	1.088
	13.6	0.847	1.105	1.089

Fig.8 Variation of maximum surface shear stress （τs″） with incoming wind speed in staggered and square arrangements

Fig.9 Comparison of shear stress partitioning between staggered and square arrays

Fig.10 Variation of fitting parameters β and m with the incoming wind speed in staggered and square arrays

Fig.11 Comparison of the present data of shear stress partitioning with previous studies

Fig.12 Variation of sand transport rate on vegetated surface with the incoming wind speed in staggered and square arrays （the fitting curve is Eq.（3））

Fig.13 Variation of f （λ） with lateral cover in staggered and square arrays

Fig.14 Variation of sand transport rate on vegetated surface with the average surface friction velocity in staggered and square arrays （the fitting curve is Eq.（4））

References 19

1	Wolfe S A， Nickling W G.The protective role of sparse vegetation in wind erosion［J］.Progress in Physical Geography，1993，17（1）：50-68.
2	Cheng H， Liu C C， Kang L Q.Experimental study on the effect of plant spacing，number of rows and arrangement on the airflow field of forest belt in a wind tunnel［J］.Journal of Arid Environments，2020，178：104169.
3	屈志强，张莉，丁国栋，等.不同配置方式沙蒿灌丛对土壤风蚀影响的对比分析［J］.水土保持学报，2008，22（3）：1-4.
4	夏建新，石学峰，吉祖稳.植被覆盖条件下地表输沙率模型［J］.应用基础与工程科学学报，2006，14（2）：218-227.
5	杨文斌，卢琦，吴波，等.低覆盖度不同配置灌丛内风流结构与防风效果的风洞实验［J］.中国沙漠，2007，27（5）：791-796.
6	杨文斌，杨红艳，卢琦，等.低覆盖度灌木群丛的水平配置格局与固沙效果的风洞试验［J］.生态学报，2008，28（7）：2998-3007.
7	徐高兴，徐先英，王立，等.梭梭不同密度与配置固沙效果风洞模拟试验［J］.干旱区资源与环境，2019，33（9）：189-195.
8	Brown S， Nickling W G， Gillies J A.A wind tunnel examination of shear stress partitioning for an assortment of surface roughness distributions［J］.Journal of Geophysical Research，2008，113：F02S06.
9	Cheng H， Liu C C， Zou X Y，et al.Wind erosion rate for vegetated soil cover：a prediction model based on surface shear strength［J］.Catena，2020，187：104398.
10	Webb N P， Chappell A， LeGrand S L，et al.A note on the use of drag partition in aeolian transport models［J］.Aeolian Research，2020，42：100560.
11	Walter B， Voegeli C， Horender S.Estimating sediment mass fluxes on surfaces sheltered by live vegetation［J］.Boundary-Layer Meteorology，2017，163：273-286.
12	Zou X Y， Li H R， Kang L Q，et al.Soil wind erosion rate on rough surfaces：a dynamical model derived from an invariant pattern of the shear-stress probability density function of the soil surface［J］.Catena，2022，219：106633.
13	Webb N P， Okin G S， Brown S.The effect of roughness elements on wind erosion：the importance of surface shear stress distribution［J］.Journal of Geophysical Research-Atmospheres，2014，119：6066-6084.
14	Kang L Q， Zhang J J， Yang Z C，et al.Experimental investigation on shear-stress partitioning for flexible plants with approximately zero basal-to-frontal area ratio in a wind tunnel［J］.Boundary-Layer Meteorology，2018，169：251-273.
15	Raupach M R， Gillette D A， Leys J F.The effect of roughness elements on wind erosion threshold ［J］.Journal of Geophysical Research，1993，98：3023-3029.
16	Marshall J K.Drag measurements in roughness arrays of varying density and distribution［J］.Agricultural Meteorology，1971，8：269-292.
17	Crawley D M， Nickling W G.Drag partition for regularly-arrayed rough surfaces［J］.Boundary-Layer Meteorology，2002，107：445-468.
18	Walter B， Gromke C， Lehning M.Shear-stress partitioning in live plant canopies and modifications to Raupach's model［J］.Boundary-Layer Meteorology，2012，144：217-241.
19	Musick H B， Trujillo S M， Truman C R.Wind-tunnel modelling of the influence of vegetation structure on saltation threshold［J］.Earth Surface Processes and Landforms，1996，21：589-605.

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[14]	LIU Shu-lin;WANG Tao;GUO Jian. Characteristics of Blown Sand Activities in Hunshandake Sandy Land in Spring [J]. JOURNAL OF DESERT RESEARCH, 2006, 26(3): 356-361.
[15]	LI Zhen-shan;ZHANG Qi-feng. Evolution of Streamwise Sand Transport with Distance [J]. JOURNAL OF DESERT RESEARCH, 2006, 26(2): 189-193.

Effect of staggered and square arrangements on surface shear stress and sand transport rate on tree vegetated surface

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