尼龙网栅栏防沙效应研究

The effects of an A-typed nylon fence on Aeolian sand prevention

通过尼龙网栅栏防沙效应的野外监测与风洞模拟实验的系统研究 ,结果表明 ,A字形尼龙网栅栏防沙体系 ,不仅具有阻沙功能 ,而且具有良好的导沙功能 ,扩展了栅栏的应用范围 ,同时也为戈壁风沙的防治提供了成功的经验 .尼龙网栅栏兼有疏透和通风两种形式 ,是一种比木质栅栏更优良的防沙材料 .其最佳孔隙度为 4 0 %～ 4 5 % ,保护区达 30 H以上 ,积沙效率在中速时超过70 % ,在特大风时也超过 5 0 % .尼龙网栅栏具有导沙性能 ,其临界角为 4 5°,如果超过 4 5°。

The effects of an A-typed nylon net fence on Aeolian sand prevention were simulated in a wind tunnel and monitored for a longterm in field.The results indicated that the A-typed Nylon net fence could not only prevent saltating particles from moving forward,but also direct them toward a given direction.This new function can widely expand nylon net fence's usage range,and especially,present a successful method on sand control in Gobi areas.The nylon net fence,with its material finer than wood fence′s,have two types such as one with its porocity of around 67.4% and the other with its porocity of around 13.8%.However,the more suitable porocity is about 40%～45% and the relative protection distance is about thirty folds of the height of the nylon net fence.Generally,the sand collecting efficiency of the A-typed nylon net fence surpasses 70% during a moderate wind speed range.Even under a stuong wind condition,the efficiency may reach as high as 15%.As for its efficiency for directing sand moving,it is very related to the angle between the fence side and the wind direction.If this angle is over its threshold of 45°,the efficiency will get down quickly.