祁连山是我国青藏高原东北部一个巨大的边缘山系。该山系位于甘肃、青海两省交界地,由数条平行山脉组成,长达八百余公里,最宽处超过250公里。山脉都呈北西西—南东东走向,最高峰团结峰达5,826.8米。

In recent 20 years, glaciers in the Qilian Shan have been retreating. In the Shiyang He basin in eastern part of the Qilian Shan, glaciers have been retreating 12.5-22.5 m/yr. The retreat of glaciers in western part of the Qilian Shan is rather small, 1.2-7.1 m/yr.Since 1975, our study on mass balance of some typical glaciers has proved that the nourishment to glaciers is’ increasing to a great extent. The firn line has descended obviously, as compared with that of twenty years ago. The biggest amplitude of descent in western part of the Qilian Shan reaches 250m. In last few years, our repeated surveys of glacier terminus have also shown that the retreat of glaciers in both western -ind eastern parts has been obviously slowing down.According to dendroclimatological analysis and statistics of soil and plants on moraines climatic data of Gansu Corridor, Glaciers as well as in the Qilian Shen advanced several times in 17th-19th centures. They began to retreat roughly in 1870 s. In general, temperature began to fall from 1950 s, and precipitation began rising after 1970. It is estimated that this trend will continue up to the end of this century.Based on above-mentioned facts and the phenomena of some glaciers with their snouts rising up and becoming steep, the retreating trend of glaciers in the Qilian Shan will soon come to an end. It will be replaced by a new period of advance.