Characterisation and comparison of spatial patterns in urban systems: A case study of U.S. cities

摘要

Understanding the morphology of an urban system is an important step towardunveiling the dynamical processes of its growth and development. At thefoundation of every urban system, transportation system is undeniably a crucialcomponent in powering the life of the entire urban system. In this work, westudy the spatial pattern of $73$ cities across the globe by analysing thedistribution of public transport points within the cities. The analysis revealsthat different spatial distributions of points could be classified into fourgroups with distinct features, indicating whether the points are clustered,dispersed or regularly distributed. From visual inspection, we observe that thecities with regularly distributed patterns do not have apparent centre incontrast to the other two types in which star-node structure, i.e. monocentric,can be clearly observed. Furthermore, the results provide evidence for theexistence of two different types of urban system: well-planned and organicallygrown. We also study the spatial distribution of another important urbanentity, the amenities, and find that it possesses universal propertiesregardless of the city's spatial pattern type. This result has one importantimplication that at small scale of locality, the urban dynamics cannot becontrolled even though the regulation can be done at large scale of the entireurban system. The relation between the distribution of amenities within thecity and its spatial pattern is also discussed.