【摘要】 通过对孔隙度为40%的栅栏式棉秆沙障内风速和风蚀风积量的观测,发现栅栏式棉秆沙障不仅可以减弱风速,而且还有很好的固沙效果.在格状沙障内,风速的降低率最大可达32%.受主风向的影响,栅栏式棉秆沙障可形成与草方格沙障不同的跨障式凹曲面,沙障内积沙的最高点不在沙障部位,因此降低了沙障被沙埋的程度,延长了沙障的寿命,提高了防风固沙的效益.更多还原

【Abstract】 A field experiment on wind velocity and the volume of wind-eroding and sand-accumulated was conducted to analyze the benefit of fence-barrier with porosity 40 % made of cotton haulm.The results showed that the fence-barrier of cotton haulm could not only reduce wind velocity but also fix sand-shifting.In checkerboard sand-barriers,the maximum decreased ratio of wind velocity reached 32 %.Duo to long-term aeolian effects and accumulated-sand,a stable concave surface was formed in the checkerboard sand-barrier by erode-accumulate balance.The formation of such concave surface is the key factor to govern that sand barriers can or cannot play a role to prevent wind and fixing sand-shifting.For the prevail aeolian impact,a cross-barrier concave was formed in fence-barrier of cotton haulm,which was different to the concave surface of straw checkerboard barrier.The apogee accumulated sand did not occurred at the position of sand barriers,so as to prevent sand barriers from being covered and take longer used time,and consequently the benefit in wind prevention and sand fixation increased and keep permanent.更多还原