青藏高原东部冻土分布特征

The Distributive Characteristics of Frozen Ground in the East of Qinghai-Xizang Plateau

研究区位于青藏高原多年冻土区的东部边缘带,发育着片状、岛状多年冻土和季节冻土。区内多年冻土面积144000km^2,占该区面积的61％。多年冻土分布主要受海拔控制,同时又呈现出纬向和经向地带性规律,平均纬度降低1°,多年冻土下界升高约130m。根据冻土平面分布的差异性,可将研究区分为四个冻土区。

The investigated area is located in the eastern fringe of permafrost area of Qinghai-Xizang Plateau, developed predominantly continous permafrost, isolated permafrost and seasonal frozen ground. The permafrost underlies an area of about 144 000 km2 or 61 % of the investigated area. The distribution of the permafrost depends chiefly on the vertical zonation, while the latitudinal zonation and longitudinal zonation, are also revealed in some extent. Generally, the lower limit of permafrost will be risen 130 m with 1 °decrease of latitude. Because of the difference in precipitation, the lower limit of permafrost in western investigated area is higher than that in eastern. According to areal differences in the frozen ground distribution as well as geomorphological and climatic factors, four regions may be recognized: Isolated permafrost region in the northeast mountain ares, predominantly continous permafrost region in the Burehanbuda Shan and Anymaqen Shan, predominatly continous permafrost region in the Bayankela Shan and sporadic permafrost region in the southeast mountain area.