青藏高原地理环境研究进展

经三纪青藏地区曾二次隆升与夷平，３，４Ｍａ以来经历了高原强烈隆起，现代季风形成，高原山地抬升、进入冰冻圈，环境剧烈波劝，高原内部干旱化及全新世环境波动变化等古寺理演化阶段。

PROGRESS IN STUDIES ON GEOGRAPHICAL ENVIRONMENTS OF THE QIANGHAI-XIZANG PLATEAU

The Qianghai-Xizang Plateau area was subject to twice cycles of uplift and planation in the Tertiary. Intense uplifting of the plateau area has given rise to drastic changes and differentiation of physical environment ofthe plateau proper since 3. 4 Ma B. P.. The plateau area rising to an elevation of 2000m a s1 at 2. 5 Ma B. P.had enhanced Asian Monsoon and resulted in lOess dePOsition. The tectonic movement during 1. 1 - 0. 6 Ma B.P. might raise the plateau area up to 3000 - 3500 mas and led the plateau entering the cryosphere and formingthe maximum glaciation. Significant environmental changes with dry tendency of the plateau proper occurredduring the last 150 ka B. P.By comparative study on several mountains of the plateau, two systems of the structure-type of the altitudinal belt are identified and may be subdivided into nine groups. A distributional model diagram relevante to highland uplift effect has been generalized. According to expeditions and studies in the 1980's , a number of strikinggeo-ecological phenomena and their spatial pattern such as moist corridor, dry valleys, high-cold shrub-meadowzone, and a high-cold arid core area are investigated and discussed. Based on the thermal conditions, moistregimes and variation in landforms, the plateau is sequentially demarcated. A tentative scheme of 2 temperaturebelts, 10 natural zones and 28 physical districts has been proposed, but not including southern slopes of the EastHimalayas.Characteristics of temperature and precipitation of the plateau since 2 ka B. P., temporal variation and spatial differentiation of air temperature and precipitation during the fifties and nineties of this century, and changes of glaciers, snow deposit and frozen ground of the plateau as well as their response to global change are dealt with in the present paper.