基于TM图像和GIS的土地利用/覆被变化及其环境效应研究

Anylysis of land use/cover change and its environment effects based on TM imagery and GIS

选择黄河三角洲垦利县为研究区,采用1987～2000年4个时相的TM数字图像,以基于知识与规则的分类方法提取土地利用/覆被信息,分析研究区土地利用/覆被的时空变化.通过筛选环境脆弱性因子,建立评价指标体系,进行了研究区环境脆弱性评价.在此基础上,通过空间叠加、缓冲区及相关分析模型,系统分析了土地利用/覆被及其变化对环境脆弱性的影响.结果显示,从1987～2000年,研究区土地利用/覆被变化明显,尤其旱地、林草地、盐荒地和滩涂转换频繁,总体生态环境表现出较强的脆弱性及明显的空间规律性;环境脆弱程度与林草地、盐荒地、水域和滩涂4种类型的面积,以及与林草地-旱地、盐荒地,盐荒地-滩涂间的转换高度相关.同时土地利用/覆被与离黄河和渤海的距离及相关水土环境条件关系密切.该研究对环境脆弱区土地利用/覆被变化及其环境效应的定量研究有借鉴意义.

Choosing Kenli County in the Yellow River Delta as the study area, using four TM digital images from 1987-2000, land use/cover information was acquired by knowledge and rule based method, and land use/cover temporal and spatial changes were analyzed. Selecting environment vulnerable factors and establishing evaluation index system, the environment vulnerability of study area was evaluated. After that, the effects of land use/cover and its changes on environment vulnerability were systematically analyzed by overlay, buffer and correlation analysis model. The results showed that the land use/cover in the study area from 1987 to 2000 changed obviously, especially the conversion among dry land, forest and grassland, salty wasteland and shoal land. The overall ecological environment was highly vulnerable and spatially regulated well. The environment vulnerability has close relationship with four land use/cover areas of forest and grassland, salty wasteland, water area, shoal land, and with the conversions of forest and grassland to dry land, salty wasteland, and salty wasteland to shoal land. In addition, land use/cover also has close relationship with the distances to the Yellow River and Bo Sea and the condition of soil and water environment. Our study was significant to quantitative study on land use/cover change and its environment effects in the environmental vulnerable regions.