塔里木河综合治理前后干流环境变化

Eco-environmental Change in the Main Stream Area of the Tarim River before and after Implementing the Comprehensive Management Project

采用TM卫星遥感影像数据,对塔里木河干流2000年和2010年的环境变化信息进行提取,分析了塔里木河近期综合治理工程实施前、后干流区土地覆盖/利用类型的变化状况,构建了塔里木河干流环境质量评价模型,对其治理前后环境状况进行了综合评价,并对比分析了塔里木河上、中、下游变化的差异性。结果表明:2000—2010年,塔里木河干流区耕地、草地、水域面积显著增加,林地和未利用地的面积显著减少,而建筑用地面积变化幅度较小;其中,林地、草地与未利用地向耕地的转化,林地向草地的转化,以及天然草地与未利用地向水域的转化是土地覆盖类型间的主要方向;塔里木河干流上、中、下游区各类型变化程度和速率存在显著差异。综合治理工程实施后,塔里木河干流环境质量总体表现出一定程度的好转,除上游处于一般级别外,其他地区仍然处于较差的环境级别;其中上、中游区环境质量评价指数(ecological index,EI)变化不明显,而下游区EI指数则显著增加,说明治理工程的实施使下游绿色走廊来水量增加,生态输水区的环境得到显著改善,地下水得到补充,两岸植被恢复明显。

In this study,the information about the environment change in the main stream area of the Tarim River Basin during the period from 2000 to 2010 was derived by using the multi-temporal Land sat TM images,and the land use / cover change in the study area was analyzed. In addition,a model of evaluating the eco-environmental quality was built to evaluate the eco-environmental change status before and after implementing the comprehensive management project. The results indicated that,during the period from 2000 to 2010,the areas of cultivated land,waters and grassland in the main stream area of the Tarim River Basin were obviously enlarged,those of woodland and unused land were reduced,and the area of construction land was changed in a small range. Moreover,the land use / cover change in the study area included mainly that the woodland,grassland and unused land were transferred to cultivated land,the woodland was transferred to grassland,and the grassland and unused land were transferred to waters. The range and speed of land use / cover change was different among the upper,middle and lower reaches of main stream of the Tarim River. Since the comprehensive management project is implemented in the study area,the waste of water resources has been reduced,the groundwater level has been raised,the natural vegetation has been regenerated,and the eco-environment has been improved.