以2002-2003年连续两年自行观测的内蒙古中西部地区二连浩特、乌拉特中旗和乌海的土壤水分为基础,重点分析了沙尘暴发生季节反映下垫面特征的土壤水分的时间变化以及大气影响对不同土壤类型(棕钙土,灰漠土,栗钙土)水分的作用。土壤水分的变化被分为3个阶段进行分析,分别是解冻期至沙尘暴开始的春季、雨期的秋季和冰雪覆盖的冬季。土壤水分受气象条件和土壤类型的影响较大。在气象条件的影响下,土壤水分含量在土壤融化期最低,在雨季达到最大值,其中以栗钙土受的影响最明显。沙尘暴发生依赖于土壤融化时间、土壤融化期的土壤条件和上年冬季的冻土深度。
Soil water content was observed continuously and automatically in Erlianhaote, Wulatezhongqi and Wuhai, northwestern Inner Mongolia, China for two years (2002-2003) in this paper. Based on the data, the temporal variation of soil water content was analyzed, which represented the characteristics of land surface. The effect on soil water content) influenced by atmosphere in different soil texture (Brown-calcium soil, Chestnut-calcium soil and Gray-desert soil) was compared. Seasonal variations of the soil water content were characterized into three stages, from thawing to active dust storm (spring), rainy (autumn) and snow cover (winter) period. The soil water content much depended .on meteorology condition. By these observations, it became clear that the soil water content was the lowest in the beginning thaw period, and was the highest in the rainy season. Differences in soil water content among the years depended on the lowest in the whole thaw period meteorological conditions The soil water content was lowest during the soil melt period, the variations of Chestnut-calcium soil was obvious under meteorology condition. The dust emission much influenced by thaw time of soil, soil wetness and the thaw period and depth of frozen soil.