西安市灰尘循环模式及搬运沉积

CYCLIC MODEL,TRANSPORT AND DEPOSITION OF URBAN DUST IN XI'AN CITY

城市灰尘的搬运沉积方式与其粒径组成密切相关。一般说来 ,粗颗粒物多以滚动方式搬运 ;中细颗粒物多以跳跃方式搬运 ;极细颗粒物多以悬浮方式搬运。西安市灰尘颗粒物主要来源于以跳跃方式搬运的中远距离颗粒物 ,其次为以滚动方式搬运的近源颗粒物 ,而以悬浮方式搬运的远距离颗粒物约占 12 %。

The transport and deposition of urban dust are highly relevant to the composition of its grain diameters. Generally speaking, coarse grains, mediate to fine grains and extremely fine grains are transported in the forms of rolling, skipping, and suspending, respectively. Urban dust grains in Xi'an come primarily from particles transported by means of skipping through relatively long or great distance, next from those transported by means of rolling from a short distance away, and, to a lesser amount, from those carried in the form of suspending through a long distance, with the last form only accounting for approximately 12% of the total grains.