Quantitative Measurement Of Urban Compactness

With the rapid economic development, and continuous declining of land resources, urban compactness has been promoted in recent years in China. The development mode of compact city has received extensive attention by the society, driving the debate about whether the compact city is good for the economic sustainable development.what kind of city is a compact city? This is a difficult question to answer. As the promotion of the compact city is now enshrined in land-use planning policy, measuring urban compactness is crucial. Many scholars have done research in this field before, but most of them used the single index measuring method or qualitative assessment. Because the single index measuring method has some limitations, and qualitative assessment can't quantify the level of urban compactness, they both are not adequate. Therefore, multiple-indicator measurement methods emerged. Such a method can measure urban compactness from various aspects.This paper puts forward several index systems to measure urban compactness in terms of population density, land use, road network, accessibility, residential building density and so on. It also presents the models of urban comprehensive compactness index (CCI) and relatively comprehensive compactness index (RCCI),. A software module "Compactness" was developed as an extension to ArcMap. It can be used to measure urban compactness based on the index systems and, the urban comprehensive compactness index and relatively comprehensive compactness index models. Two applications were developed to test the software module. One was to measure the compactness of a hypothesized city-Zhong Gang in2005and2010, and the other assessed the compactness of a real city-ShangHai in China. The results demonstrateed that the system is effective and practical for urban compactness measurement and management. Finally, the paper analyses and looks into the urban compactness measures and the designed software package, and puts forward some directions for studying urban compactness in the future.