降尘过程指示的沙尘循环过程

 大气降尘过程受诸多因素的影响，如沙尘源区的性质、输送距离、降雨量等。利用甘肃省10个城市15 a间(1986—2000年)的降尘监测资料与气象资料，主要分析了沙漠戈壁区与黄土区降尘的差异及原因。结果表明：①西北干旱区的降尘量主要与沙尘事件频次有关；②沙漠戈壁区的大气降尘量大于黄土高原区；③降尘量在强沙尘源区，呈现出显著的高值中心。随着沙尘自西向东输送，降尘通量随输送距离的增加而减少。

Dust Cycle Process Indicated by the Dust Deposition Process

There are many factors influencing the process of dust deposition,such as features of the sand dust source areas,dust transporting distance,rainfall,and so on.Based on dust-fall data of ten cities in Gansu Province from 1986 to 2000,we analyzed the difference of dust-fall fluxes between desert/gobi area and Loess Plateau area,and illustrated the reasons that caused the difference.Results are as follows:(1)The dust deposition fluxes in arid area in Northwest China are major associated with dust event frequency;(2)The dust-fall amount in desert/gobi area is larger than in Loess Plateau area;(3)The dust deposition fluxes show high values in the major dust source areas and they reduce as the transportation distance increase when the dust transports from west to east.