起沙风速的观测方式及其影响因素研究综述

起沙风速作为研究风沙运动规律、解决风沙工程问题的关键指标之一受到广泛关注。学者们根据研究目的及内容的不同总体主要采用两种研究方法:一是利用风速仪在野外进行直接测量;二是在之前学者研究的基础上,利用理论模型,通过计算临界摩擦速度等求得起沙风速。学者们在选择研究方法时会以研究内容作为参考,而起沙风速的影响因素是其中重要的一项。起沙风速受多种因素的影响,通常情况下:①起沙风速随粒径的增大而增大,但含水量变化会使这种现象发生改变;②植被覆盖度越大、植被类型越丰富、组合模式越复杂起沙风速越大;③地表结皮率、砾石覆盖度、地表粗糙度等均会对起沙风速产生影响。

Review on Observation Methods and Influencing Factors of the Threshold Wind Velocity

As one of the key indexes to study the law of sand movement and solve the issues of sand blowing engineering,the threshold wind velocity of sand movement has been widely concerned.According to different research purposes and contents,scholars mainly adopted two research methods.One was to use anemometer to measure directly in the field.Second was to use the theoretical model to calculate the critical friction velocity of sand movement on the basis of previous studies.When scholars chose research methods,they would take the research content as a reference and one of the important factors was the threshold wind velocity.The threshold wind velocity is affected by many factors,under normal conditions,it is that a)the threshold wind velocity increases with the increase of particle size,but it is changed by moisture content;b)the larger the vegetation coverage,the richer the vegetation types and the more complex the combined model is,the higher the threshold wind velocity is and;c)the factors of surface crust rate,gravel coverage and surface roughness all have an impact on the threshold wind velocity.