青藏高原可可西里卓乃湖溃决出露湖底多年冻土形成过程的监测与模拟

利用可可西里卓乃湖综合监测场获取的气象、地温等数据资料，分析了卓乃湖溃决后出露湖底融区冻土的形成过程。结果表明卓乃湖溃决后的三年时间里，多年冻土下限深度分别达到4.9 m、5.4 m、5.7 m，呈现出不断增长的趋势。利用Lunardini构建的冻土形成过程模型模拟了多年冻土的形成速率和形成过程，并在此基础上初步分析了地表温度和土壤含水量对研究区多年冻土形成速率的影响。模型模拟结果显示研究区多年冻土将继续增长，多年冻土的形成速率呈现先快后慢的增长趋势并最终达到稳定状态。地表温度和土壤含水量是影响多年冻土形成的重要因素。随着温度的降低，多年冻土的形成速率逐渐加快。当地表温度不变时，在多年冻土形成初期，岩土含水量越小，多年冻土的形成速率越快。

The formation of permafrost in the bottom of the Zonag Lake in Hoh Xil on the Qinghai-Tibet Plateau after an outburst:monitoring and simulation

In September 2011,Lake Zonag,a famous lake in the Hoh Xil area,was broken after years of expansion and the lake body shrank dramatically.Permafrost developed on the bottom of the lake after the lake outburst.Based on the data of meteorological and ground temperature by the lake,the formation process of permafrost on the bottom of the lake was analyzed.Observation data indicated that the permafrost base increased to 4.9,5.4 and 5.7 m,respectively,in 2012,2013 and 2014 in borehole 1.By using numerical model,the rate and process of permafrost formation were simulated.Simulation results show that the thickness of the frozen soil layer increases with time,and that it will take 200 years for the frozen soil to reach 30 m.The lower the temperature,the faster the formation of frozen soil.When the surface temperature is unchanged,the rate of permafrost formation will decrease with the increase of soil water content.