摘要
大小兴安岭多年冻土处于欧亚大陆多年冻土带南缘, 地温高、厚度小、热稳定性差、对气候变暖的敏感性强.过去40 a来该区多年冻土退化主要表现为最大季节融化深度增大, 厚度减薄, 地温升高, 融区扩大, 多年冻土岛消失等.气候变暖及该区森林植被的锐减是导致多年冻土退化的普遍性和基础性因素, 而多种人为活动影响起了加速促进作用.依据多年冻土南界与多年平均气温的密切相关关系, 据1991-2000年平均气温-1.0～1.0 ℃等值线给出了现今多年冻土南界位置, 并探讨了未来40～50 a后气温升高1.0～1.5 ℃情况下多年冻土南界的可能北移情况.
In the southern margin of permafrost zone of the Eurasian continent, permafrost in the Da and Xiao Hinggan Mountains is warm, thin, thermally unstable and subsequently sensitive to climatic warming. During the past 40 years, permafrost has been degrading as evidenced by deepening active layer, thinning of permafrost, rising ground temperatures, expansion of taliks, and disappearance of permafrost islands. Detailed analyses indicate that climatic warming and sharp reduction of forest coverage during the past century are the general and basic reasons for the degradation of permafrost, and increasing human activities have been accelerating the retreat of permafrost. Based on the close correlations between the southern limit of permafrost （SLP） and decadal average air temperatures, present positions of the SLP are delineated using the multi--year average air tempera- ture isotherms of —1. 0-1. 0 ℃ during 1999—2000. The SLP would shift northwards upon a projected warming of 1.0- 1.5 ℃during the next 40- 50 years, but with significant uneven variations in different parts.
出处
《冰川冻土》
CSCD
北大核心
2006年第4期467-476,共10页
Journal of Glaciology and Geocryology
基金
中国科学院百人计划项目"气候变化条件下温暖多年冻土区线性工程稳定性"(2004407)资助
关键词
大小兴安岭
多年冻土南界
多年冻土退化趋势评估
气候变暖
森林采伐
Da and Xiao Hinggan Mountains
southern limit of permafrost
assessment of permafrost degradation trend
climate warming
deforestation
