从土地覆盖变化看塔里木河中下游天然草地的退化

Study on Grassland Degradation at the Middle and Lower Reaches of Tarim River by Monitoring Land Use

通过GIS技术和1990～2000年的TM影像图,分析了塔里木河中下游近10年的土地覆盖动态变化,结果显示:在塔里木河中下游地区,天然草地退化严重,高、中覆盖草地大幅减少,低覆盖草地的数量虽然增加但主要是流域河岸胡杨林群落退化后向荒漠灌丛草地演化的结果;而在自然环境更加恶劣的塔里木河下游地区,随着断流和地下水位的下降,天然草地正在向裸地和沙地演变。通过分析,提出了恢复塔里木河中下游天然草地的治理建议。

Based on GIS technology and TM images (during 1990～2000),the dynamic change of land use pattern at the middle and lower reaches of Tarim river is shown in this paper.The results indicate that the proportion of high coverage and middle coverage grassland is decreasing in this area,and the proportion lower coverage grassland increases at the expense of the natural Populus euphratica and the cultivated land wasted.At the same time,the natural grassland is disappearing and degrading toward desert at the lower reaches of Tarim river.In a word,the whole tendency of degradation is desertification.Some suggestions are discussed in this paper for restoring the degraded natural grassland in this region.