Study on Windproof Effect of Wind-Rolled Plant High Vertical Sand Barrier
Wind-rolling dispersal is an important form of plant seed dispersal and individual expansion,which has important ecological significance.Many wind-rolled plants exist in both grassland and sandy land,which move un-der the action of air flow in winter and spring and pile up around various obstacles.Among them,the wind-rolled barriers formed by net fences are more common,and such barriers also have obvious blocking effect on the transit wind sand.To investigate the windbreak effect of wind-rolled plant barrier,this study simulated the interception of different quantities of wind-rolled plants by net fences,and designed three kinds of sparse,medium,and dense wind-rolled plant vertical sand barriers(barriers with a height of 1 m),and studied the windbreak efficiency,wind-break sand dynamic roughness and wind speed flow field characteristics through field tests.The influence of sand barrier engineering parameters such as height and permeability on wind control efficiency was explored,which was intended to provide reference for new methods and technologies of sand control.The results showed that:(1)the vertical sand barrier of wind-rolling plants could affect the characteristics of the surrounding wind field up to the dis-tance of 7 H and the height range of 0-90 cm behind the barriers.(2)Dense,medium and sparse sand barriers were able to significantly reduce the intensity of transit wind speed,with good wind prevention efficiency.The minimum wind speed of the three sand barriers appeared at the distance of 3 H behind the barrier,but with the increase of thin-ning permeability,the wind protection efficiency of the sand barriers showed an increasing trend,and the maximum wind protection efficiency appeared at the distance of 10 cm behind the dense thinning permeability barrier,which could be up to 50%.(3)Dense,medium and sparse sand barriers could all increase the surface roughness,and the three sand barriers all showed a trend of dense>medium>sparse,and the maximum value of roughness appeared in the dense and sparse permeability,which could reach 2.97 cm.The high vertical sand barrier of wind-rolling plant could effectively affect the transit wind speed and had a good windproof effect,which can provide reference for the application of sand control.
sand barrierventil levelwind speed flow fieldMu Us Sandy Land
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