试论青藏高原多年冻土类型的划分

本文采用综合分析与主导因素相结合的原则，以干燥度作为主要指标并参考年降水量，年平均相对湿度及气温较差等，结合地形因素将青藏庙的多年冻土划分为：湿润，亚湿润，半干旱，干旱和极干旱５种类型，并对各类型代表性和冻土地区进行分别论述。

ON THE CLASSIFICATION OF PERMAFROST ON QINGHAI-XINZANG PLATEAU

Qinghai-Xizang Plateau is a permafrost area with the highest elevation and largest area at the middle and low latitudes in the world. The causes of its permafrost formation are quite complicated. Controlled by many factors, there are the obvious regional differences on the permafrost distribution and structure, under ground ice, permafrost and periglacial phenomena, etc. Bases on the principle of synthetical analysis and dominant factors, this paper classifies the permafrost on Qinghai-Xizang Plateau into five types, i.e. humid, sub-humid, semi-arid, arid and extremely arid types by taking the aridity as a dominant index and annual precipitation, mean annual relative humidity, annual variation range of air temperature and lanforms as the auxiliary indexes. Each type of the permafrost is discussed separately in the paper. It is considered that the suitable conditions for the developmerit of the permafrost on the plateau are the long -term cold -dry climate, moderate amount of moisture in the surface soil, and vast land area.