小兴安岭黑大公路沿线多年冻土分布及退化状态  

Distribution and Degradation of Permafrost in Xiao Hinggan Mountains along the Heihe-Dalian Highway

作　　者：王彪 盛煜[2] 刘建平 

机构地区：[1]黑龙江省高速公路建设局,黑龙江哈尔滨150036 [2]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2001年第3期302-306,共5页Journal of Glaciology and Geocryology

摘　　要：黑大公路沿线多年冻土主要分布于黑河 -北安段 ,属小兴安岭岛状多年冻土区 .该区存在的多年冻土是晚全新世寒冷时期的产物 ,现处于欧亚多年冻土南界边缘 .多年冻土发育在低洼、地表积水、塔头草生长茂密、草炭和泥炭发育的沼泽化湿地当中 .沼泽湿地独特的热交换特性决定了其中发育的多年冻土处于退化的最晚阶段 ,冻土的退化在自然条件下可能依赖于由下至上的地下热流 .多年冻土的地温剖面表现为零梯度曲线且冻土温度接近于 0℃ ,由此决定了多年冻土对人为活动干扰的敏感性 .There exist island-permafrost in the Heihe-Bei'an Section of the Heihe-Dalian Highway. It was considered that the permafrost formed in the cold period of the Late Holocene, and has been degraded since the 19th Century. It is located in the margin of the south boundary of Eurasian permafrost at present. According to the meteorological observation at Sunwu Station, which is in the mid of the Heibei-Bei'an Section, air temperature was keeping a steady state from 1954 to 1980, and then obviously increases from the 1980s. This implies that there is a warming trend in the section. Field exploration indicated that the permafrost develops in swampy, waterlogged, hassock, flourishing and thick peat underlying lowland. However, it does not imply that permafrost must appear in all of swampy wetlands. The qualities of wetland, including water supply, peat thickness etc., have great significance in the degradation of permafrost. The special pattern of heat exchange on the swampy wetland surface decides that the underlying permafrost would be in the final stage of permafrost degradation. The degradation depends on the upward underground thermal flux under a natural condition. Temperature of the permafrost is very close to 0℃, with a temperature gradient near zero, showing that it is very vulnerable. To choose pre-thawing method instead of protecting permafrost from thawing is a good ideal. The method is an effective treatment in highway construction in such a permafrost region.

关 键 词：小兴安岭 多年冻土 分布 退化 地下热流 人为活动 地温剖面 

分 类 号：P642.14[天文地球—工程地质学]