关键词: 民勤绿洲, 水资源变化, 生态系统退化

Abstract: Shiyanghe River Basin is a typical exemplification of ecological-balance being disturbed and ecosystem being degraded in inland river basin of arid and semi-arid zone of China. Through long-term observation and study on the runoff water exploitation and the oasis vicissitude in recent period, the allocation of water resources, the precipitation character and its effect on vegetation, the change of underground water table and water quality in lower reaches of the river basin, we find out that precipitation is not favorable to the growth of natural vegetation; the increase of population accompanied with the uneven distribution of water resources has resulted in the overuse of water and the abrupt descending of groundwater table, which caused the degeneration of ecosystem. In other word, the function of regional economic factors promotes the change of social factors, following the vicissitude of natural environment. The social, economic and natural factors interplay and by force of water resources variation to drive the ecosystem of Shiyanghe river basin to change continuously.

Key words: Miqin oasis, water resource change, ecosystem degeneration