车尔臣河流域土地利用变化及生态环境效应分析

借助ArcGIS与ERDAS软件,以1990年、2000年、2010年遥感影像Landsat TM/ETM为数据源,提取3期车尔臣河流域土地利用/覆盖利用图.在土地利用类型与区域生态风险之间的经验联系基础上,推求出土地利用类型生态风险指数,进而获得研究区域生态安全指数,建立了车尔臣河土地利用类型与生态环境之间的数量关系.同时,在空间尺度上将研究区分为若干特定研究单元,并对整体及局部地区进行生态环境质量动态分析.结果表明:1990—2010年间,车尔臣河流域总体生态环境指数呈逐步升高趋势,但生态环境质量的改善与恶化两种趋势并存,并在特定研究单元上出现明显的区域分异特征;盐碱地向耕地、林地及低覆盖度草地的转化,低覆盖度草地向林地的转化和未利用地向耕地的转化是环境改善的主导因素,林地与中覆盖度草地向盐碱地和未利用地的转化是环境恶化的主导因素.

Land use change and eco-environment effect in Qarqan River basin

By using softwares such as ArcGIS and ERDAS and based on Landsat ETM/TM remote sensing image of 1990, 2000 and 2010 as data source, three stages of land use or cover pictures of Qarqan River are obtained in this paper. On the basis of the relationship between the type of land use and regional ecological risk, ecological risk index of the type of land use is calculated, regional ecological safety index is also acquired, and the quantitative relationship between the type of land use of Qarqan River and ecological environment is established. In this paper, the research area is divided into a number of specific research units on spatial scale, and dynamic analysis of ecological environment quality is conducted for the overall and local area. The result shows that the overall ecological environment index of Qarqan River has an upward tendency from 1990 to 2010, but improvement and deterioration of ecological environment coexist and the specific research units show significant spatial difference; transformations from saline soil to cultivated land, woodland and low coverage grassland, from low coverage grassland to woodland and from unused land to cultivated land are major factors of environmental improvement, whereas transformation from woodland and moderate coverage to saline-alkali soil and unused land is the major factor of environmental degradation.