南京城市扩展的遥感研究

卫星遥感影像为数据源， 以GIS为制图和数据提取的分析手段， 通过引入城市扩展强度、重心坐标、紧凑度、弹性系数等指标，研究了南京城市扩展的时空规律、形态特征以及与人口发展之间的协调关系；并应用回归分析，筛选了能够解释城市扩张的主要社会经济因子。结果表明：①南京城市扩展的时空分异特征明显，江南主城的东北-西南轴向和东南的江宁一带成为城市扩展最活跃的地区；②城市扩展过程中，紧凑度降低，空间形态向着趋于不稳定状态发展；③ 21世纪以来，城市扩展的弹性系数向着逐渐合理化的方向转变，但在1988~2001年，该指数与合理数值有一定差距，城市扩展与人口增长速度之间出现了不和谐现象；④国家和地方相关政策的引导及自然因素的影响对于南京城市扩展起了重要作用，职工年平均工资的增长和非农业人口的增加也是影响南京城市扩展的主要社会经济因子。

RESEARCH ON URBAN EXPANSION IN NANJING,CHINA USING RS AND GIS

Taking Landsat MSS/TM/ ETM satellite remote sensing images as data resource.and GIS as charting and analysis method,the relationship between the space and time rule and the shape characteristics of the urban construction land expansion of Nanjing City and the population development were analyzed in this paper,with such indexes as construction land expansion intensity,the centre coordinates,compact ratio,and elasticity coefficient.Using correlation analysis method,the main factors affecting the urban con- struction land expansion were also identified in this paper.It was revealed that the spatial-temporal varia- tion characteristics of Nanjing urban construction land were obvious from 2001 to 2004.and that Jiangnan main city northeast-southwest axial and the southeast Jiangning area were the most active expansion parts. Furthermore,during the urban expansion process,compact index reduced and the spatial shape developed to an unsteady state.Since the 21st century,the construction land expansion has been transforming gradually to rationalization direction;but from 1988 to 2001,the expansion elasticity coefficient was insufficiently rea- sonable;related policy guidance and natural factors were the main affecting factors,and the growth of aver- age salary and the increase of non-agricultural population also played an important role.