Soil moisture variation in south Gurbantunggut Desert.

With soil moisture distribution profiles selected in the Gurbantunggut Desert,the soil moisture and environmental factors of the typical sandy dunes were analyzed with multiple comparison methods.Temporal variation characteristics of soil moisture were analyzed according to water-supplying period,desiccation period,frozen stagnant water period.The measurements of soil moisture were arranged in the following order: water-supplying period'sdesiccation period's frozen stagnant water period's.The coefficient of variation of soil moisture was put in following order: water-supplying period's frozen stagnant water period's and desiccation period's.The results of the study show as follows: there are significant differences(P0.05) in different aspect areas' soil moistures,the average soil moisture of north slope is larger than that of sunny slope's,and there are significant soil moisture differences(P0.05) among dune's different areas: the lower area between dunes is characterized by high soil moisture,large amplitude and deep variation depth;the dune top is characterized by low soil moisture,small amplitude and shallow variation depth;and both slopes of dunes are placed between lower area and dune top mentioned above relating to soil moisture.According to vertical variation of soil moisture,soil layers can be divided into three ones: active layer,transitional layer and stable layer.There are significant differences(P0.05) between the active layer and transitional layer(and stable layer).Rainfall and temperature are the important factors affecting the temporal distribution of soil moisture,to which the soil moisture is closely related(P0.05,F=0.02).