摘要
风成沙广泛分布于我国干旱与半干旱地区，是我国风蚀与风沙活动的主要载体。风洞模拟实验发现：风成沙的风蚀可蚀性随粒度的变化服从分段函数，０．０９ｍｍ粒径者最易被风蚀。风成沙颗粒按可蚀性可以分为３种类型：＞０．７ｍｍ和＜０．０５ｍｍ为难蚀颗粒；０．７０．４ｍｍ，０．０７５０．０５ｍｍ为较难蚀颗粒；０．４０．０７５ｍｍ为易蚀颗粒。在相当粒径的条件下，混合沙粒较均匀粒径者易风蚀。风成沙的风蚀强度与实际作用风速／起动风速之比密切相关，可表达为：Ｅ＝Ａ＋Ｂ×ＥＸＰ〔－Ｃ×（Ｖ／Ｖｔ）〕，其中Ｅ为风蚀率，Ｖ为实际作用风速，Ｖｔ为起动风速，Ａ，Ｂ，Ｃ为回归常数。
Aeolian sand, distributed extensively around Chinas arid and semi arid zones, is the main bearing body of wind erosion in China. It is discovered that the change of wind erodibility of aeolian sand with its grain size complies with discontinuous function, 0.09mm sand being the most susceptible to wind erosion. The erodibility of aeolian sand can be divided into 3 extent categories: difficultly erodible, >0.7mm, and <0.05mm; moderately erodible, 0.7￣0.4mm, and 0.075￣0.05mm; most erodible, 0.4￣0.075mm.With similar grain size, the mix sized is more susceptible to wind erosion than the uniform sized. The wind erosion rate of aeolian sand is closely related to the ratio of acting wind velocity/threshold wind velocity,the function can be established, E=A+B× EXP -C(V/V t) , where E is wind erosion rate, V is acting wind velocity, V t is threshold wind velocity, A,B and C are regression constants.
