关键词: 塔河下游, 植被, 沙漠化, 地下水变化, 响应分析

Abstract:

Over the last 50 years, the human irrational exploitation and utilization to water, land and biological resources has lead to the drying up of lower reaches of Tarim River nearly 30 years, which intensified the deterioration of originally arid environment. The water table reduced from 3~5 min 1950s to 8~12 min 2000, and natural vegetations reduced year by year, only the serious degraded grassland area made up to 57.5% of the total grassland area in the lower reaches, both desertification area and desertification grade increased year by year. From May 2000 to October 2007, emergency water supply was carried out for nine times. Consequently, the groundwater level near the river bank rose to some extent; the natural vegetation gradually recovered, the biggest vegetation coverage was even larger than 90%; the living plant species increased from 3~4 kinds before the project to more than 10 species after the project. Besides, some of environmental factors which originally caused desertification changed advantageously, correspondingly the desertified area and its degree decreased.

Key words: lower reaches of Tarim River, vegetation, desertification, groundwater change, response