近三十年来昆明市建成区扩展遥感监测与分析

以遥感影像为数据源,借助GIS技术提取了6个时期的昆明市建成区扩展及对周边土地占用的信息.在此基础上,利用扩展弹性系数、分形维数等方法分析了昆明市1974～2004年建成区扩展的时空特征、土地利用类型演变过程,以及与人口增长之间的协调关系,并应用相关分析和主成分分析方法,对影响昆明市建成区扩展的社会经济因素进行分析.结果表明:30年来昆明市建成区扩展了3.07倍,1974～1988年的14年间,仅增加了13.36km²,而1988～2004年的16年,增加了144.07km².其增长速度与市区人口增长速度相比,有时超前有时滞后.建成区是以老城区为核心沿东北、西南、东南三个方向呈“星形”扩展.其扩展占用的土地主要是耕地.自然因素对建成区的扩展形态起着限制作用,社会经济因素是建成区扩展的内在推动力,政策和规划对建成区扩展起着引导和促进作用.

Remote Sensing Monitoring and Analyzing of the Urban Built-up Land Expansion in Kunming in 1974 ～ 2004

Urban expansion influences the regional environment remarkably because there are many human activities concentrating on it. This paper took Kunming which is a major city locating on the Yunnan-Guizhou Plateau as a study area. The expansion of Kunming urban area in different periods during 1974 -2004 was obtained by using one Landsat MSS image and five Landsat TM images. The spatial-temporal features of the urban expansion and the relationship between population growth and urban expansion during the 30-year period were analyzed by using expansion speed, expansion elasticity and fractal dimension. The research shows that the built-up area in 2004 is 3.07 times larger than that of in 1974. The expansion rate is distinct from each other and Kunming has experienced two fast expansion stages in 1992 - 1996 and in 2000 -2004. Considering the relationship between the construction land area and population, the urban sprawl rate of Kunming did not match urban population growth during the study years. The increase of the fractal dimension value before 1992 shows that the built-up land sprawled out from inner city in a radial way while the decreasing value after 1992 shows the city sprawls by the way of low-density fill between main roads. ＇The cultivated land is the primary land use type converted to urban land use which accounts for one half of the urban area increment in each stage during 1974 -2004. The natural environment is the limiting factor to the urban expansion. The economic development especially the increase of GDP and the growth of average salary is the fundamental driving force. The policy and the urban planning are the guidance of extension of the urban built-up land.