STUDY ON TRANSPORT MECHANISM OF SAND-DUST STORM AND THE ENVIRONMENTAL FEATURES OF ITS SOURCE GROUND

In the present paper, the origin, transport and the geographical environment of sand-dust storm are investigated deeply. The results show that the origin of the sand-dust storm depends mostly on the natural factors such as soil feature on the ground, climate condition and vegetation states on the ground. The dry and loose sand-dust particles on the recovered land are the base material forming sand-dust storm. Rare rainfall and dry air are the climate factors by which the sand-dust storm could formed. The hot cyclone is a starting force of sand-dust. The atmospheric circulation is the transporting force of the sand-dust storm. There are three transport patterns of the sand-dust particles on the ground. They are wriggling, transition, and suspension. The distance and the direction of sand-dust transport depend on the atmospheric circulation. There are the source grounds of sand-dust storm mostly in the hinterland in China. There are some characters in the area of the source grounds of sand-dust storm such as wide and plain lands, grit and sand composted soils, uncovered, dry and loose soils on the ground. There is not nearly vegetation in the source grounds of sand-dust storm. The climate of the source grounds of sand-dust storm is dry, and the rainfall is rare. There is strong wind in winter and spring. The human activities make the desert areas become larger than before and the sand-dust storm become more and more serious.