Effect of staggered and square arrangements on surface shear stress and sand transport rate on tree vegetated surface
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 trans-port rate of rigid tree models in staggered and square arrangements are measured in wind tunnel,and the differ-ences 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 parameterβ of staggered arrangement(mean=220)is larger than that of square arrangement(mean=180),while the param-eter 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 ar-rangement.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.
surface shear stresssand transport ratearrangement modetree modelwind tunnel tests
NETL
NSTL
万方数据
维普
