快速城市化地区的土地利用时空动态变化研究 --以南京市为例

20年来，在中国城市化快速发展的过程中，一系列与城市化相关的环境问题随之产生。六朝古都——南京，作为我国经济最发达的长江流域四大中心城市之一，其快速的城市化过程也不可避免地带来了同样的环境问题。为了研究南京市的城市化和土地利用变化规律及其对水文过程的影响，利用1987、1998、2000年的三期遥感数据，通过分层分类的方法对各土地利用类型进行专题信息提取，结合GIS技术，获得研究区1987~1998,1998~2000年两个时段的土地利用变化转移矩阵。据此全面分析了南京市的土地利用时空变化特征。结果表明：南京市13年来，城乡居民及建设用地以大量蚕食耕地而显著增加，年均增幅达到1.92％；耕地和未利用地则明显减少，年均减幅分别为0.62％ 和1.21％；林地和水域有所增加，主要来自未利用地的转变，剩余12.35％的未利用地则转化为城乡居民及建设用地。引起这一土地利用变化的主要驱动力是人口的增长和经济的发展以及政策制度的激励和导向作用。

SPATIAL-TEMPORAL CHANGES IN LAND USE PATTERNS IN FAST URBANIZATION REGIONS -A CASE STUDY IN NANJING,CHINA

Types of land uses are extracted from remote sensing images obtained in 1987, 1998 and 2000. The land use conversion matrixes in the study area over two periods, 1987-1998 and 1998-2000 were analyzed based on GIS. During the 1987-2000 period, the proportion of lands with conversions was as high as 5. 84% among the total lands. The settlement and built-up areas increased distinctly and farmlands decreased obviously in the last 13 years. There are two major types of land use changes-conversion from farmlands to settlement and built-up areas, water surface areas, tea gardens and orchards, and conversion from bare lands to forest lands. These two types of land use changes constitute about 89. 96% to the total changes. Farmlands loss has been the largest figure among different types of changes during this period. Nine thousand and two hundred ninety-four of farmlands lost in the study area, accounting for 9. 36% of the total farmlands. Smaller area underwent changes from water surface areas to farmlands, forest lands to farmlands, and bare lands to settlement and built-up areas, ponds and reservoirs. The main driving force of land use changes is the policy shifts due to the demand of social-economic development and population growth.