山西最大冻土深度时空分布特征

基于山西68个气象观测站1960—2018年月最大冻土深度资料,应用EOF和小波分析等方法,研究山西年最大冻土深度的时空分布特征。结果表明:(1)1960—2018年山西68站平均年最大冻土深度平均值为71 cm,极端最大值为192 cm,极端最小值为7 cm。近59 a山西68站平均年最大冻土深度呈显著减小趋势,气候倾向率为-1.394 cm·(10 a)^(-1),且在1986年发生一次显著的气候突变。(2)山西68站平均年最大冻土深度存在准4 a周期。(3)山西年最大冻土深度空间分布整体上南浅北深、东浅西深。(4)山西年最大冻土深度EOF分解前2个模态的累积方差贡献率达58.4%,第1模态空间型为全省一致型,第2模态空间型为南北反向型。

Spatial-temporal distribution characteristics of maximum frozen soil depth in Shanxi Province

Based on the monthly maximum frozen soil depth at 68 meteorological stations in Shanxi Province during 1960-2018,the temporal and spatial distribution characteristics of the annual maximum frozen soil depth in Shanxi were studied by using EOF and wavelet analysis methods.The results are as follows:(1)The average annual maximum frozen soil depth at 68 stations in Shanxi during 1960-2018 was 71 cm,the extremely maximum value was 192 cm,and the extremely minimum value was 7 cm.In the past 59 years,the average annual maximum frozen soil depth at 68 stations in Shanxi showed a significantly decreasing trend with a climate tendency rate of-1.394 cm per decade,and it mutated in 1986.(2)The quasi-4-year period of average annual maximum frozen soil depth at 68 stations in Shanxi was detected.(3)The annual maximum frozen soil depth showed a spatial distribution characteristics with shallow in southern and deep in northern Shanxi,shallow in eastern and deep in western Shanxi.(4)The accumulated variance contribution rate of the first two modes of the annual maximum frozen soil depth in Shanxi reached 58.4%.The spatial pattern of the first mode was consistent in the whole province,while that of the second mode was reverse in southern and northern Shanxi.