THE CAUSES AND DEVELOPMENTAL TREND OF DESERTIFICATION IN THE MIDDLE REACHES OF THE YARLUNG ZANGBO RIVER AND ITS TWO TRIBUTARIES IN XIZANG

Key words: 
• desertification /
• eco-environment /
• the Yarlung Zangbo River /
• Xizang

Abstract: The middle reaches of the Yarlung Zangbo River and its two tributaries are an important development and construction region in Xizang(Tibet) in recent years, but the fast development of desertification has caused immense damages to its social and economic development, so the study on desertification in this region is significant. The paper studies the causes and development trend of desertification in this region through analysis of natural and human factors as well as their relationship. It can be concluded that desertification in the study area is one process which is accelerated and intensified by human activities on the basis of the slow natural desertification process. It is resulted from the dislocation of irrational and intensive human activities, fragile eec-environment and meagre natural resources, and tends to become more wide and severe.