Soil Moisture Distribution and Moisture Restoration in Dried Soil Layer in Northern Qinghai Lake

According to the determination of soil moisture content at Shaliuhe town in the northern Qinghai lake,this paper researches problems of the soil moisture content and the recovery of dried soil layer.Results show that with the increase of depth,the content of soil water decreases in Shaliuhe town,when the annual precipitation was slightly more than 400 mm,the moisture content of most dried soil layers recovered,dried soil layers disappeared,but there still existed few dried soil layers.After 2009,the year of the precipitation increase,the recovery of soil moisture reached 1.3 m depth in 2011.In 2011 the content of soil water was significantly higher than that in 2009.When the annual precipitation was about 410 mm,the recovery of soil moisture that reached 1.3 m depth needs about two years.The water movement is slow in this area,so the recovery of dried soil layer needs significantly longer time than that on the Loess Plateau,and the depth of soil moisture recovery is smaller,which is mainly determined by the longer soil freezing period.The recovery of soil moisture shows that the output of water was slightly less than the input from 2009 till now in this area.