关键词: 黑河流域, 不同类型土地沙漠化, 驱动力分析

Abstract: The history and present status of land desertification in Heihe river basin were analyzed. It was proved that the main cause of desertification forming and developing was irrational human economic activities, besides natural factors, such as such as fragile eco-environment, high evaporation, arid and windy climate, sparse precipitation and loose surface materials, etc. Irrational use of limited water resources has resulted in the overuse of water resource in the upstream basin, consequently, the downstream basin was short with water shortage, the vegetation degraded. In the long term land development processes, human economic activities severely disturbed the hydrological cyclic processes, caused a series of hydrological effect and eco-environmental changes: some lakes dwindled or dried up, river cannel shifted, discharge and salinity changed and land desertification took place. The geomorphologic conditions of arid oasis also affect oasis development. Natural disasters are often beyond man's control power and pose serious threat to human existence and development. The channel relocation is often a direct cause for the abandonment of oases. Wars also caused the alternation of farming and grazing and destroyed the farmland water projects. Policies could affect the immigration and emigration of people, the expansion or shrinkage of oases and the oasis structure and function, the management and use of water resources. In other word policy has a significant real-time effect on the oases. In a word, both the natural driving forces and human driving force play a great role in the desertification of the oasis but human activity is the leading factor.

Key words: Heihe river basin, different types of desertification lands, dynamic factor analysis