黄河源区土地利用/覆被变化及其生态环境效应

应用1989年TM影像和2005年ETM+影像提取黄河源区两期土地利用/覆被数据,并利用GIS的空间叠加分析对两期土地利用图进行土地利用动态信息的提取。在建立黄河源区土地利用数据库的基础上,采用生态环境质量指数模型建立各土地利用类型与生态环境质量之间的数量关系,定量的分析土地利用变化对生态环境质量的影响。结果表明:①黄河源区1989-2005年间,土地利用变化缓慢而匀速,存在着生态环境的恶化和改善两种相反的趋势。在大尺度范围内,生态环境质量相对稳定,有轻微的恶化,但是在研究区局部范围内,生态环境质量变化显著;②植被是影响黄河源区生态环境质量的主要因素,其中草地对环境质量的影响处于主导地位;③利用生态环境质量指数模型不仅可以从整体上了解研究区生态环境质量,也可以发现影响区域环境质量的主要驱动力。

Land Use/Cover Change and Associated Effects on Eco-environment in Source Region of Yellow River

Through interpreting TM image in 1989 and ETM+ image in 2005, the land use/cover database of the source region of the Yellow river had been established, and then the land use/cover dynamic information was derived by overlaying the database of land use/cover. Based on the land use/cover database, an eco-environment quality index model was used to establish the quantitative relation between land use/cover type eco-environment effect. The results show as follows: ①The change of land and its use/cover was slow and moderate, and two contrary changing trends of degradation and improvement in eco-environment coexisted. In the large region scale, the eco-environment quality kept relatively stable in the period of 1989-2005, but changed significantly in the small scale.②Vegetation was the major factor that affected the eco-environment quality in the source region of the Yellow River, followed by grassland factor. ③The eco-environment quality index model can not only be used to study the eco-environment quality in the region scale, but also to find the main driving force of affecting the eco-environment quality.