Types and Characteristics of Modern Periglaciation along the Qinghai Xizang Highway
Wang Shaoling (Lanzhou Institute of Glaciology,and Geocryology, Academia Sinica)
This paper deals with thermal moisture regime and material conditions for the devel-opment of periglacial phenomenon in the permafrost area along the Qinghai-Xizang Highway. The external agent of modern periglaciation is very strong and the periglacial phenomenon are various in kind on the Qinghai-Xizang Plateau. The action of the external agent and distribution of the periglacial geomorphological patterns depend chiefly on the elevation as well as the latitude. The periglaciation on the plateau can be vertially classified into the following five zones: The high-mountainous snow-ice action zone, the strong frost weathering zone, the frost heave, freeze-thaw sorting and gravitation zone, the frost heave, freeze thaw and water flow action zone, and the seasonal frost and wind erosion zone. It is found that the zonation of periglaciation coincides with that of the natural landscape and that of the high-altitude permafrost.