Formation of dust storms are required to have 4 conditions.Dust on the ground substance. It is the material basis of the formation of dust and sandstorms.Is the second winds. This is the formation of sand-dust storm power base, is also capable of long distance transportation of dust storms power guaranteed.Three unstable air. It is an important local thermal conditions. Dust storms occur in the afternoon on the importance of end of thermal conditions in the evening.Four is an arid climate environment. Spring dust storms occur in the North, and rainfall does not occur over time after dust storms is a very good evidence.Spring desert of edge area, due to long-term drought, and surface rare vegetation cover, dang has Gale comes of when surface of dust is easy was blowing since and was lost moved, but due to sand grain diameter larger, easily formed hanging moved (suspended moved, is small particles substances guarantee long distance lost moved of necessary), therefore cannot long distance lost moved, this is from dust more far of area only dust and rare Yang Sha of main causes. If the wind continues for very long, formed of suspended dust can be transported far away, area will appear along the sand-dust storm; when the winds diminished to a certain extent, dusty land, dust appears on the weather. If rainfall at this time, it will form the so-called "mud and rain".From sandstorm formed process by needed of 4 a conditions see, loess plateau, and vast of desert and the by man-made factors of damage are is desert of process in the of land, North spring late farming of land and the is construction process in the of based facilities (as Expressway,) for sandstorm of occurs provides has full of substances source; and Spring North area of drought, also makes sandstorm occurs of possibilities enhanced; Gale of produced is a complex of atmospheric phenomenon, main is front activities or Jingwei to circulation adjustment role of results. Thus results both dust storm was a variety of complex factors, destruction of nature by human activities leading to increased land desertification, had a very important role on occurrence of dust storms, and in recent years the global drought (the reason for this is not yet known) abnormal weather phenomena such as also played an invaluable role in occurrence of dust storms. So said human activity only for sandstorms play a role and it cannot be said that dust storms are caused by human factors.
Romy莎莎mei
