近10年来黑河流域生态环境变化特征分析

Features of Eco-Environmental Changes in Heihe River Basin over Recent 10 Years

对比分析黑河流域 13万km2 范围内 2 0 0 0年遥感影像数据资料及 1987年流域遥感影像资料 ,结果表明 :近 10年来黑河流域生态环境总体上仍然向恶化方向发展 ,流域内天然森林分布面积减少 6 .35 % ,中游取代下游成为流域沙漠化发展的主导区域 ,上游山区土地沙漠化发展最为迅速 ;下游草地生态退化十分强烈 ,草地面积减少达 2 0 95 .39km2 。但局部或生态环境的某些方面出现明显逆转。

Selecting the 13 items of land use or land cover index, which indict the changes of regional eco-environment, from the remote sensing data of 2000 over the whole river basin with an area of 13.0×104?km2. At the same time, the remote sensing data from 1987 was analyzed to output the eco-environmental index of 1987. Comparing with the two time phase analysis results of eco-environmental index, and integrating the field surveying results, the trends and extent of eco-environmental changes in the Heihe River basin were analyzed. The features of eco-environmental changes were quantitatively discussed. Those features showed that, in recent 10 years, the eco-environment of the Heihe River basin was degrading as a whole. Forest area in the river basin decreased by 6.35%. The middle reaches, which replaced the lower reach, was the most serious desertification region, and the upper reaches was the rapidly exacerbated desertification region. Grassland ecology showed a continuous degradation tendency in the lower reaches, the total area of degraded grassland occupied 2?095.39?km2. But in some regions of the river basin, the eco-environment was improved.