咸阳市区街道灰尘粒度特征分析

Analysis on Particle Size of Street Dusts in Xianyang City

对2008年4月咸阳市区采集的街道灰尘样品进行了粒度分析。结果表明,咸阳市街道灰尘粒度呈双峰分布特征,第一众数为35～75μm,第二众数为280～500μm,平均粒径为80μm;峰态较宽而且比较对称,分选性较好,与黄土和现代尘暴降尘的粒度分布模式相似。街道灰尘样品粒度由北西至南东无明显规律变化。街道灰尘沉积是由于大气环流对远、近不同距离粗细颗粒物的混合搬运的结果,应是风积作用的继续。在适当的大气动力条件下,咸阳市街道灰尘颗粒大约有56.7%可以进入大气悬浮搬运。

The analysis of particle size of street dusts in Xianyang City collected in April,2008 indicates a bimodal distribution spectrum with the first mode being 35~75 μm and the second,280~500μm.The averaged particle size is found to be 80 μm.The distribution is characterized by wide kurtosis,better symmetry,and better sorting,which is similar to the particle size distribution of loess and modern dust storms.This indicates that street dusts are a mixture of coarse particles derived from local area and fine partic...