城市规模衡量、变动类型识别与空间联系——基于卫星灯光数据

A Measurement of Urban Scale,Expansion Types and Connection:Based on the Night-time Light Data

城市规模是城市经济、社会相互作用的产物,伴随经济和技术的快速发展,城市规模空间变化更具多样性。城市体系内原有的城与乡、新区与旧区、先进与落后、核心区与边缘区等内部异质性问题变得更加突出。为更好地反映城市空间变化带来的其所承载的经济、技术和社会活动变化,促进经济技术转型升级,需以新方法识别城市规模变动类型与空间联系变化。使用夜间卫星灯光光斑来衡量城市规模,将灯光光斑和地级市数据匹配后的研究结果显示,光斑衡量的城市规模与人口、土地总量显著正相关,表明在分析城市规模空间联系时,其作为城市规模的替代变量有一定合理性。将光斑分为亮、暗两区,根据相对变化方向和速度,识别城市规模变动类型,主要有"内聚型"和"蔓延型"两类,多数城市属后者。比较两类城市的空间联系,发现蔓延型城市间的空间联系比内聚型城市间要强,而分别用光斑和亮区衡量城市规模时,两类城市空间联系并不一致。结论印证了城市蔓延是普遍的空间现象,同时证实了城市蔓延"空间组织"能力强,是城市规模空间关系演化的主导力量。研究结论对新时期优化城市空间格局有一定参考意义。

This paper attempts to measure urban scale based on the night-time light data,and the facula is divided into bright and dark areas to analyze expansion types and connection. The results show there is a significant positive relationship between the facula and land or population,which indicates that it can be used as an alternative variable of urban scale. Based on the rate of change in the bright and dark areas,the cities can be divided into two types： centralized and decentralized. From the perspective of connection,the decentralized cities are stronger; from the perspective of competition between ＂bright areas＂,there is no significant difference between the two types cities. This means that the extensive incentive is too strong,while the intensive incentive is insufficient in terms of urban scale.