Relation between Soil Moisture and Occurrence of Dust Storms in Central Inner Mongolia, China

抄録

　To study the influence of soil moisture on dust storms, the variety of daily mean soil moisture, daily mean wind speed and their integrative contributions are analyzed in the paper based on hourly soil moisture data observed from April 2001 to June 2003 and recorded meteorological data in central Inner Mongolia, China. The rationality of the statistic results were discussed, from which some interesting results can be drawn as follows: 1）The minimum value of daily mean wind speed during the dust storms is 3.5m/s, and a dust storm would certainly occur when the wind speed exceeds 8m/s in this area. 2）In 18.4% of the whole data, when dust storms occurred, and in 81.6% of the whole data when no-dust storm occurred when the wind speed was above 3.5m/s. This indicated that the dynamic factor of daily mean wind speed is not the most important influential factors for occurrence of dust storms. 3）Considering the soil moisture and wind speed only, when an inverse relation between daily mean soil moisture and daily mean wind speed comes into existence, dust storms would occurred (r=-0.674). Otherwise, dust storms would not occur. The result indicates that formation and development of dust storms is an integrative result of soil moisture and wind speed. Continuous data of soil moisture would be an effective index to research dust storm for showing the humid status of soil directly and for scaling the status of vegetation cover indirectly.