Study On Wind Protection And Sand Fixation Effects Of Sand-bag Barrier

This article measured 1m×1m, 2m×2m, 3m×3m sand-bag barrier three specifications of sand-transporting quantity, ratio of reducing wind velocity, wind erosion and deposition three indicators, simulated sand-bag barrier wind velocity flow field, the barrier within the vegetation survey in the southeast edge of Ulan Buh Desert. To bare sand dunes and straw sand barrier as a contrast, comprehensive analysis of wind protection and sand fixation effects ofsand-bag barrier.(1) In height of 0~2cm, relative sediment contents of the same size straw sand barrier and sand-bag barrier were same, which accounted for 50% of bare sand dunes, 0~10cm height, relative sand-transporting quantity of straw sand barrier a were about 20% lower than that of sand-bag barrier, sand-bags barrier were 20% lower than bare sand dunes, accounted for 50% and 75% of bare sand dunes respectively. From the point of views of sand-transporting quantity, sand-bag barrier was inferior to straw sand barrier, but played a very important role for sand dune-fixing.(2) Windproof effect on sand-bag barrier, 1m×1m and 2m×2m, 1m×1m and 3m×3m existed a significant difference (P<0.01), the windproof effect of 2m×2m and 3m×3m was not significant (P>0.1); 1m×1m was the best of three for windproof, followed by 2m×2m, the worst was 3m×3m.(3) Based on the CFD simulation, the result of the windproof effect of sand-bag barrier: wind velocity and height is certain, the size of 1m×1m sand-bag barrier on the effect of wind more effective than 2m×2m and 3m×3m, the smaller the size of the greater wind disturbance. Size and height is certain, with the increase of wind velocity, wind velocity of near the surface barrier and outlet of 2m high is increased, and effects of windproof is decreased. Wind velocity and size is certain, with the increase in high barrier, the sand barrier on the near-surface winds are weakened.(4) From the point of views on wind erosion and deposition, with the same size of sand-bag barrier and straw sand barrier, compared to tow barrier of sand stability does not exist significant differences (P> 0.1).(5) In sand-bag barrier and straw sand barrier in the restoration of vegetation survey showed that two sand barrier on vegetation height, density and coverage of the impact there is no significant difference (P> 0.1).