毛乌素沙地流动沙丘土壤水分对降雨的响应

为探讨半干旱区流动沙丘土壤水分对降雨的响应,采用AV-3665R型雨量传感器、ECH₂O-5土壤水分传感器同步监测毛乌素沙地东北缘流动沙丘2013年降雨及0～200 cm深度土壤体积含水量动态,分析土壤水分含量变化特征、降雨入渗特征及降雨对土壤水的补给作用。结果表明:5-11月累积降雨399.4 mm,显著(p<0.01)影响0～200 cm深度土壤水分含量; 且0～200 cm深度土壤体积含水量较低(6.49%±1.12%)时53.8 mm降雨、较高(10.22%±1.96%)时24.2 mm降雨湿润锋能够到达200 cm; 试验期间399.4 mm累积降雨对土壤水有一定补给作用,其中45.7±14.1 mm降雨蓄存在0～200 cm深度土壤中,占同期降雨的(11.4%±3.5%,且随着时间的延长,蓄存水大部分将渗漏到200 cm以下补给深层土壤水。

Response of Soil Moisture to Rainfall in the Mobile Dunes of the Mu Us Sandy Land

To investigate soil water content to response time for rainfall in the semi-arid area of the mobile dunes. The AV-3665R-type rain sensor and ECH₂O-5 soil moisture sensor to quantitative monitor precipitation, soil water for 0-200 cm deep in the mobile dune of the Mu Us Sandy Land northeastern margin in 2013. Analysis of soil moisture variations, infiltration of rainfall and soil water recharges characteristics for rainfall. The results showed that cumulative rainfall 399.4 mm was significantly (p<0.01) affect 0-200 cm soil moisture in the mobile dune when lower average moisture of 0-200 cm (6.49%±1.12%), 53.8 mm rainfall was able to infiltration into the 200 cm soil, when higher average moisture of 0-200 cm (10.22%±1.96%), this value was 24.2 mm. Cumulative rainfall 399.4 mm have recharge the following soil moisture of 200 cm during the test, which 45.7±14.1 mm moisture accumulated in the soil, account for 11.4%±3.5% of the rainfall, and with the time increasing most of the soil accumulate water will leak into 200 cm and then recharge deep soil water.