新疆冬春季积雪及温度对冻土深度的影响分析

利用新疆64个气象台站1960-2010年的气象资料,分析了新疆50 a来冻土深度的变化趋势,并讨论了温度(平均地温、平均气温)、降水(冬春季年降水、平均积雪深度)与冻土深度(平均冻土深度、最大冻土深度)的相关关系.结果表明:以10 a时段的年代际变化分析,新疆50 a来平均冻土深度和最大冻土深度均呈明显减小趋势.50 a来平均冻土深度全疆、北疆、南疆分别减小了约7 cm、10 cm、4 cm,最大冻土深度则分别减小了约11 cm、16 cm、9 cm.新疆50 a来平均气温和平均地温均呈波动上升趋势,且与冻土深度均有着良好的相关性,其与平均冻土深度的相关系数分别达到了-0.67、-0.77,与最大冻土深度的相关系数也分别达到了-0.51、-0.65,地温与气温的上升对应着冻土深度的减小.新疆冬春季年降水与冻土深度有着较好的相关性,其与平均冻土深度、最大冻土深度的相关系数分别达到了-0.40、-0.37.新疆的平均积雪深度与冻土深度也有着一定的弱相关,其原因与积雪对地面的保温作用有关.

Analyzing the effect of snow cover in spring and winter and air temperature on frozen ground depth in Xinjiang

In this article, based on the meteorological data from 64 meteorological stations from 1960 to 2010, the changing trend of frozen ground over the past 50 years in Xinjiang are analyzed and the relations between temperatures (average ground temperature and air temperature), precipitation in spring and winter, average snow depth and frozen ground depths (averaged one and the maximum one) are discussed. The following conclusions can be drawn: (1) Viewed 10 years as a span, both the average frozen ground depth and the maximum frozen ground depth over the past 50 years have decreased steadily. The average frozen ground depth has decreased 7 cm, 10 cm and 4 cm, respectively, and the maximum frozen ground depth has decreased 11 cm, 16 cm and 9 cm, respectively, in Xinjiang, North Xinjiang and South Xinjiang; (2) Average air temperature and ground temperature in Xinjiang have increased undulately and have good correlation with frozen ground depth, with correlation coefficient of -0.67 and -0.77, respectively, with average frozen ground depth, and -0.51 and -0.65, respectively, with the maximum frozen ground depth. The rise of ground temperature and air temperature means decrease in frozen ground depth; (3) Annual precipitation in winter and spring has better correlation with frozen ground depth, with correlation coefficients with average frozen ground depth and the maximum frozen ground depth of -0.40 and -0.37, respectively. Besides, the average snow depth in Xinjiang has a few relativity with frozen ground depth, due to the insulating effect of snow on the ground.