关键词: 沙漠化, 发展程度

Abstract:

The middle reaches region of Yalutangpo River in Tibet is a part high-frigid areas of Qinghau-Xizang plateau. There are many environmental problems, in which the land desertification is a most out sanding problem. For. protecting and improving itself ecological environment, the desertification prevent and cured is first thing of all. Through the field investiagated and the map of desertification compiled. The paper disscuess that the classification of desertification degree and their indicators and distributive regulation. Based on the results of measures all kinds types desertified lands. The total area of desertified lands is 1860.9 sq kilimetres. According to the degree of desertified development, we divide desertified lands into slight, mediate, severe three types. The areas of the types respectively 530.5km², 752.8km², 578.6km², Acording to the land surface texture, the desertified lands can be divided into sandy and sandy-gravels the areas of the two types respectively 916.4km², 944.5km², In the respect of distributive regulation. The desertified lands mian distributs volley area, especially in the widen-volley of Yalutangpo River. The areas of desertified land are largest in the region. It also extends form volley beach to the pediment fluvial fan and hillside, meantime, the paper also raises the problems of cutivated lands erosion in the middle reaches region of Yalutangpo River.