大小兴安岭多年冻土的主导成因及分布模式

大小兴安岭海拔高度由北向南增高对纬度偏低带来的温升具有相对补偿功能,从而使冻土分区界线大大南凸。大兴安岭山地为一个连续的整体,不宜仅将南部视为山地多年冻土,而将中、北部划为高纬多年冻土。多年冻土南界应在黄岗梁山南麓通过。小兴安岭的多年冻土南界应在呼兰河源中山的南麓通过。大兴安岭北端断续多年冻土区应将伊勒呼里山平均海拔1000 m的中山部分包括在内;岛状融区多年冻土区南伸至阿尔山附近终结;小兴安岭南端汤旺河与呼兰河的河源区存在岛状融区多年冻土闭合圈。

Causes, South Borderline and Subareas of Permafrost in Da Hinggan Mountains and Xiao Hinggan Mountains

Based on other scholars' research,the paper establishes a new distributing pattern of permafrost in the Da Hinggan Mountains and Xiao Hinggan Mountains.It has made important progress in the formation causes and distribution pattern of the permafrost,but the conclusion that the permafrost was engendered mainly by latitudinal zonality,which was a part of Eurasian permafrost zone,should be discussed.The paper considers vertical zonality the dominant action in the formation of the permafrost. The elevation of the Da Hinggan Mountains and Xiao Hinggan Mountains heighten gradually from north to south.The descending temperature coming from elevation rising compensated the ascending temperature coming from low latitude relatively.The result made the types and subarea borderline protrude to south enormously.Taking the Da Hinggan Mountains as a whole,it was not feasible to take the south as mountain permafrost only.So,the south permafrost borderline of the Da Hinggan Mountains was in the south of Huanggangliang Mount and also 120 km south to Aer Mount.The south permafrost borderline of the Xiao Hinggan Mountains was in the south of middle mount nearby the Hulan River.The sheet permafrost subarea in the north of the Da Hinggan Mountains should include the region with an elevation of about 1000 m of Yilehuli Mount.That was to say,the east borderline of it was 70 km east to Xinlin.The insular thawy region of permafrost subarea in the Da Hinggan Mountains extend from middle chine of Yilehuli Mount to Aer Mount.And there were closed loops of insular thawy permafrost in middle mountains nearby the Wangtang River and the Hulan River in the south of the Xiao Hinggan Mountains.