THE ORIGIN AND THE DISTRIBUTION OF THE SOURCES OF THE SAND-DUST STORMS

Sand-dust storms are a disastrous weather generated by strong winds, which carry a large amount of sand and dust from the surface of the earth into the sky. The level visibility is below 1000 meters when a sand-dust storm takes place. Sand-dust storms increase the process of the desertification of the farming land and is also a concrete symbol of the degrees of the desertification of the farming land. The origin of the sand and dust in the sand-dust storm forms the indispensable material condition.The factors of the formation of the sand-dust storms, the sorts and the distribution of the sand and dust, the origin of the sand and dust and the latest study progress were summarized on the basis of the analysis of the recent documents in this field.