THE RESPONSE OF SOIL MOISTURE TO PRECIPITATION IN FIXED SAND DUNES OF ARTEMISIA ORDOSICA COMMUNITY IN MU US SANDY LAND

For a thorough analysis of the response of soil water content to precipitation, rainfall infiltration characteristics and the replenishment of precipitation to soil moisture in fixed sand dunes of Artemisia Ordosica community in Mu Us sandy land, we used AR-5 soil moisture automatic monitoring system for a long-term and continuous monitoring of soil moisture measuring, and a new rainfall sensor monitoring system named AV-3665R was also used in this study. The results showed :(1) In the study area, the accumulative rainfall, which was 332.75mm in the growing season, had a significant on the soil water content at 0-120cm soil layer. The precipitation before August only affected the soil water content above 80cm soil layer; from August to October, the precipitation of had a significant effect on the soil water content at 0-120cm soil layer. (2) When the initial soil water content was low, the infiltration depth of the rainfall occurred on May 19th was between 80-100cm, and the soil water content at 0-40cm soil layer could reach the peak value. When the initial water content of soil was high, the infiltration depth of the rainfall occurred on August 20th was between 120-160cm, and the soil water content at 0-80cm soil layer could reach the peak valve. Both of the precipitation had a significant effect on soil water content. (3) The soil storage volume at 0-200cm soil layer increased by 16.3mm in the growing season, accounting for 6.1% of the rainfall in the same period. The results showed that the precipitation in the study area had a certain amount of recharge to soil moisture at different soil layers.