【摘要】 根据我国东北部71个气象台站近30a各深度的月平均地温值,通过绘制冻结过程线,寻找出各站多年平均最大季节冻结深度值,并算出该深度处多年平均温度值(t(?))。分别建立(t(?))与多年平均气温、与多年平均气温较差的相关关系,并进行t(?)与气温、较差和多年平均1月最大积雪深度间的多元回归分析。借助关系式及基于以往对冻土温度状况的认识,划出各冻土分带的地温范围,勾画出各冻土带内冻土温度和分布的复杂状况。以冻土分布与气温和地温关系为基础,探讨在气候持续变暖情况下东北各冻土分带界线及南界的可能变动。更多还原

【Abstract】 Based on the mean monthly ground temperature during the past 30 years from the 71 meteorological stations in northeastern China, the mean annual maximum depths of seasonal freezing at each station are determined by the ground freezing curve, and the mean annual ground temperatures (tξ) at those depths are calculated. Good correlations exist among tξ, the mean annual air temperature (ta), the mean annual range of air temperature (Aa) and the mean annual maximum snow depth in Jan. (hs). The tξ shows positive correlation with ta and hs respectively, but tξand Aa show negative correlation. By the study on tξ, the ground temperature ranges in each permafrost zone are given and the complexity of permafrost temperature and permafrost distribution are delineated. The research results lead us to hold the opinion that in the northeastern permafrost region, the seasonal freezing and thawing processes belong mainly to the transitional and semi-transitional type, which is sensitive to the environmeatal changes and the temperature transitions from 0℃ occur easily. According to the relationship of permafrost distribution to air and ground temperature, the possible changes of permafrost under the influence of climate warming is estimated in this paper. The permafrost southern limit has retreated by 20-30 km northward for the past 100 years with a temperature rise of 0.7℃. Consequently, if the air temperature rises by 1 ℃ gradually until the middle of next century, the southern limit will retreat by 80-200 km northwardly and 32% of the present permafrost will disappear. Given a temperature rise of 3℃ until the end of next century, the permafrost southern limit will drawback to the north of Da Hinggan Ling, and only 36% of the present permafrost will be preserved then. This paper also points out the need of researches on the time lag of permafrost changes and the even stronger developping processes of some permafrost phenomena under the climate warming.更多还原