建国以来南京城市扩展研究

论文以南京市为研究区,以1949、1976年航空影像,1988-2003年陆地卫星(MSS、TM、ETM+等传感器)遥感影像为数据源,利用遥感信息提取技术,获取南京市城市扩展信息。结合南京市经济社会数据,从扩展强度、人口-城市扩展指数、分形维数、扩展方向等方面分析了南京市城市扩展的时空变化特征,并从自然、经济、社会等方面探讨南京城市扩展的驱动力。研究结果表明:①1949-2003年南京城市规模扩展了10.15倍,城市扩展表现为3个阶段:1949-1976年为第一阶段,城市扩展表现为低强度的准圈层式外延;1976-1988年为第二阶段,城市扩展强度有所提高,圈层外延与跳跃式发展并存;第3阶段为1988-2003年,扩展强度达到18.79%,跳跃式发展和连接式发展表现突出;②城市扩展呈现沿轴线扩展的特征,扩展轴沿长江向东北-西南方向延伸,城市重心向北部振荡后向东南方向转移;③南京城市扩展在城区和郊区分别表现为紧密扩展和稀疏扩展,1949年以来,南京城市空间形态日趋复杂,但自进入21世纪后,城市空间形态趋于稳定,表明南京城市扩展存在由无序向有序发展的趋势;④城市扩展是多种因素综合作用的结果,在不同的扩展阶段,不同的因素组合占主导。总体上看,经济发展是城市规模扩展的主导因素,城市空间格局、空间形态的变化更多地受政策因素的影响。交通等基础设施的建设拉大了城市框架,行政区划调整为城市扩展提供了空间,城市总体规划为城市扩展提供了空间导向。

Urban Growth in Nanjing since 1949

The process of urbanization is speeding up along with the development of socio-economy.As a result,urban area grows rapidly.Research on urban growth using RS and GIS has become a focus in recent years by geographers,and it’s meaningful to put more emphases upon urban growth study and lead urban growth by constituting effective policies and measures.Urban boundary information of Nanjing was extracted from aerial photos (1949 and 1976),Landsat MSS (1988),TM(1997,2000 and 2001),and ETM+(2003)images with supervised classification after principal component analysis.Based on the urban growth intensity,the population-urban growth index,the fractal index,the urban growth orientation,the urban gravity transfer model,etc.,this paper analyzes characteristics of urban spatial-temporal change in Nanjing city,Jiangsu province. The driving force of urban growth in Nanjing is discussed form the view points of physical condition,social-economy,etc.,and we concluded that:(1)The urban area expanded by 10 times in Nanjing from 1949-2003.The urban growth process can be divided into three phases: the urban growth maintained slow from 1949 to 1976 with a pattern of quasi-loop expansion and an intensity of 1.85%;then it speeded up from 1976 to 1988,with an intensity of 8.55% and quasi-loop expansion existed together with a leap-forward pattern;subsequently,it kept rapid expansion after 1988,with a pattern of leap-forward and join and an intensity of 18.79%.(2)For the obstruct of the Yangtze River,urban growth presents an“Axis Mode”,and the growth axis is extending along the Yangtze River (viz.from north-east to south-west);meanwhile,the direction of the gravity transfers toward south-east after wavered toward north.(3)As a result of urban growth,morphology of the urban expansion maintained stable after becoming complex,and became more and more reasonable.Urban growth intensity in each district in different periods from 1949 to 2003 is different from each other,and urban growth kept loose in the suburbs and compact in the city proper.(4)The existing urban land border and shape were formed under the joint efforts of many forces,such as socio-economic force,physical condition,and so on.The dominant forces in different phases are different from each other.In the point of quantity of urban growth,development of economy was the leading driving force,and policies were the main factors influencing spatial pattern and spatial morphology.The improvement of infrastructure,especially,transportation extended urban frame, and the adjustment of regionalism provides space for urban growth which is oriented by general urban planning.