中国城市人口分布的幂次现象

Power Law Distribution of Urban Population in China

摘要: 幂次法则是一个普遍存在于自然科学和社会科学中的现象，在城市中也不例外。尽管对于形成这种现象的幕后机制仍在试图理解之中，但城市中的幂次现象仍然有其重要的意义。这一现象是客观规律在城市人口分布整体特征中的自发涌现，不仅可以作为自上而下构建理论的依据，而且可以作为自下而上进行城市复杂系统模拟的基础，尤其可做为我国政府制定城乡均衡发展政策的参考。本文通过大量城市人口数据统计，发现我国城市人口分布的R2值很大，说明我国城市人口分布符合幂次法则。而且q值在1附近，说明符合位序–规模法则。从1999年到2009年的演化过程来看，我国城市人口分布的幂次现象日趋加强，斜率q最近几年远离−1，说明城市趋于不均衡发展。

Abstract: Power law is a common phenomenon in natural and social sciences, including cities. Though many attempts have been made to understand the underlying mechanisms of the power law phenomenon, it means a lot to cities. This phenomenon is a manifestation of an emerging, objective law in urban population distribution, which can serve as a basis not only for theory construction from the top down, but also for simulations on urban complex systems from the bottom up, in particular as a reference for urban and regional policy making in China. Through mass urban population statistics, we found in the present paper that the R2 values for the urban population distribution in China were high, indicating that distribution fulfills the requirement of the power law distribution. In addition, the q values scattered around unity, fulfilling the requirement of the rank-size rule. Starting from 1999 through 2009, the evolution toward the power law of the urban population distribution in China intensified, with the slope of q moving further away from −1, indicating imbalanced development of cities.