城市蔓延定量表达和机理分析——以南京市为例

以南京市为例,将南京市分为城区和郊区,涵盖1996～2002以及2002～2008年2个时段,运用ArcGIS分别提取每年每个区的建设用地信息,对南京市11个地区的城市蔓延发生程度及其内在机理进行分析比较。蔓延发生的程度用蔓延指数表示,主要从增长弹性以及松散度2个方面测度,增长弹性用单位新增人口的建设用地消耗量计算,松散度则用每个区域的轮廓周长和面积之比计算,最后进行简单平均法得出每个区的综合蔓延指数,从结果可以看出南京市蔓延多发生在郊区,并且蔓延发生与人口增长、行政区划调整、大型项目用地与全球化密切相关。最后提出控制城市蔓延的对策。

Research on Quantitative Expression and Mechanism of Urban Sprawl with Nanjing as Example

Taking Nanjing as an example, dividing Nanjing into urban area and subway area, covering two periods of 1996 -2002 and 2002 - 2008, using ArcGIS, the construction land information of each region in each year was extracted. Urban sprawl degree and inner mechanism of 11 regions in Nanjing was compared and analyzed. The calculation of measurement includes growth elasticity and loose degree, growth elas- ticity means the rate of population increase and construction increase, loose degree means the rate of perimeter and area of every regional. Fi- nally, comprehensive sprawl index was obtained. From the result, sprawl mainly occurred in suburb and closely related with population growth, administrative division adjustment, large projects land, globalization. Several countermeasures for controlling urban sprawl were put forward.