Study On The Denefits Of Vertical Sunflower Stalk Strip Sand Darrier Wind And Sand Darrier

Based on field observations and wind tunnel experiments,this study investigates the changes of wind speed,flow field distribution,sand transport and surface erosion characteristics of near-surface wind and sand transport under different vertical sunflower straw strip sand barrier configurations(barrier height-H,porosity-P,row spacing-R).The wind velocity,flow field distribution,wind and sand transport and surface erosion characteristics of different vertical sunflower straw sand barriers are studied to clarify the mechanisms of barrier height,porosity and row spacing on the wind and sand transport patterns near the surface,and to reveal the effect of wind and sand control.The study also quantitatively evaluates the wind and sand control benefits of different vertical sunflower straw sand barricade configurations and optimizes the vertical sunflower straw sand barricade configurations in order to provide theoretical basis and practical guidance for regional engineering measures to prevent and control sand,and to achieve a win-win situation for agricultural waste resource utilization and desertification control.The research results showed that:1.After laying the ribbon-like sand barrier of sunflower stalks,different degrees of weak wind areas will be formed on the windward side and leeward side,and the weak wind area will decrease with the decrease of barrier height and the increase of porosity.Among them,barrier height is the key factor affecting the effective protection distance of the barrier,porosity is the key factor affecting the wind speed of the barrier at close range,and the effective protection distance of the vertical sunflower stalk sand barrier with different configurations is between 6～10 H*(barrier height times).The average wind speed near the surface decreased by 5.43%～62.63%,and the roughness increased by 3.89～225.66 times after laying the sunflower stalk sand barrier,and this effect was negatively correlated with porosity and row spacing,and positively correlated with barrier height.2.The near-surface sand transport rate of vertical sunflower stalk sand barrier with different configurations with height distribution conforms to the three-parameter index function.The lower the barrier height and the greater the porosity,the greater the creeping sand transport rate in the sand barrier,the faster the decay rate with the increase of height,and the closer the sand material transport is to the surface,and vice versa.After laying the sunflower stalk sand barrier,45.16%～97.38% of the transit sand transport was intercepted by different configurations of sand barrier,and the sand barrier effect was the most affected by porosity,followed by row spacing,and the barrier height was the smallest.3.The overall difference between roughness,windproof effect and sand barrier effect under field measurement and wind tunnel observation was small,and there was no significant difference(P>0.05),which shows that the above wind tunnel observation results are accurate and can provide technical support for field observation.4.Based on the above mechanism analysis,the effect of barrier height(H),porosity(P)and row spacing(R)on the effect of wind and sand resistance was summarized,and combined with the cost analysis,it was concluded that the three configuration sand barriers H40cm-P40%-R2 m,H40cm-P40%-R3 m and H40cm-P50%-R3 m had better wind and sand control benefits,and the weighted comprehensive scores of wind and sand prevention benefits reached 0.75,0.80 and 0.74,respectively,and the evaluation grades were above good and had promotion potential.