大同市冻土气候变化初探

利用大同市所辖8个站1962—2012年地面气象观测记录中的冻土资料，采用线性倾向估计、累积距平等方法，分析大同市土壤开始冻结期、完全解冻期、冻结期及最大冻土深度的变化特征及其影响因素。结果发现：51年中大同市冻土主要表现为最大冻土深度减小, 开始冻结期推迟,解冻期提前, 冻结持续期缩短的总体变化趋势，冻土除了受气温的影响外，局地因素对最大冻土深度的影响较大。

Variation of Frozen Soil in Datong in 1962-2008

Using the meteorological observation records of frozen soil from eight stations during the period of 1962 to 2008 in Datong, by means of linear trend estimation and accumulated anomaly methods, an analysis is made of the variation characteristics and influencing factors of frozen soil, such as the dates of beginning to freeze and completely defrosting, freezing duration, and the maximum depth of frozen soil. The results show that the largest permafrost depth reduced; the date of freezing beginning delayed; the date of defrosting advanced, the freezing duration shortened in general. Frozen soil is not only affected by the temperature, and local factors have great influence on the maximum depth of frozen soil.