The Contribution of Soil Moisture to Dust Storm in Western and Central Inner Mongolia, China

Abstract

To recuperate the shortage of soil moisture, based on hourly soil moisture date observed from April 2001 to June 2003 in western and central Inner Mongolia of China, the change regulation of daily mean soil moisture and daily mean wind speed and their integrative contributions are analyzed in the paper. Then rationality of the statistic result is discussed, from which some interesting results can be drawn as follows: (1)The minimum value of daily mean wind speed for dust storm emission is 3.5m/s, and dust storm will occur when the wind speed over 8m/s in this area. (2)There are 18.4% of dust storms that occurred and 81.6% of non-dust storms that occurred in the total data collected when the wind speed was more than 3.5m/s. It indicated that dynamical factor with daily mean wind speed is not a most important one in the factors of dust storm emission. (3)If only soil moisture and wind speed are consider, when there is a inverse relation between daily mean soil moisture and daily mean wind speed, dust storm would occurred (r= -0.674). Otherwise, if their relation were not shown as this inverse, dust storm would not occur. The formation and development of dust storm is an integrative result of soil moisture and wind speed. Continuous data of soil moisture would be an avail index to study dust storm for showing the humid status of soil directly and for scaling the status of vegetation cover indirectly.