青海湖北土壤水分分布与土壤干层恢复

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

通过对青海湖北沙柳河镇土壤含水量的测定,研究了该区土壤水分含量和土壤干层恢复等问题。结果表明:青海湖北沙柳河镇土壤含水量随着深度的增加而减少,在年降水量略多于400 mm的条件下,多数土壤干层中的水分得到了恢复,干层消失,少数土壤还有干层存在。在2009年降水增多,到2011年土壤水分恢复深度达到了1.3 m,2011年土壤含水量显著高于2009年。在年降水量为410 mm左右的条件下,土壤干层恢复到1.3 m深度需要的时间为2年左右。该区土壤水分运移缓慢,干层恢复比黄土高原缓慢,恢复的深度较小,这主要是该区土壤冻结期较长等决定的。土壤干层中水分的恢复表明,该区2009年以来草原土壤水分输出量略小于输入量。

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 pre-cipitation 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.