国家城市等级体系的世界格局

World pattern of national urban hierarchy system

为了克服首位度分析的简单化,避免位序-规模模式的不可比性,选取国家最大城市人口规模（P）、城市首位比（R）和城镇等级体系不平衡指数（S）3个指标来分析国家城市等级体系的世界格局.首先将156个国家的城市人口分为10～25万、25～50万、50～100万、100～500万以及500万以上5个等级,计算出城镇等级体系不平衡指数（S）和城市首位比（R）,剔除S=1的31个国家,然后对P,R和S采用系统聚类法（Hierarchical cluster）和自组织映射法（SOFM）来揭示国家城市等级体系的世界格局.结果表明,国家城市等级体系的空间格局可以分成6大类型：高级-中级平衡型、中级平衡型、初级平衡型、初-中级不平衡型、初级不平衡型和初级首位型.分类结果说明利用自组织特征映射法（SOFM）对国家城市等级体系进行分类,分类效果较好,可以反映城市等级体系国家间的异同.

In order to overcome the simplicity of the primacy index and the incommensurability of the ranksize model,this paper selects unbalanced index of the urban hierarchy system（S）,the population of the largest city（P）and urban primacy ratio（R）to study the world pattern of national urban hierarchy system.On this basis,firstly the 156 national city population is divided into 10～25million,25～50million,50～100million,100～500 million,more than 500 million of 5grade,calculating unbalanced index of the urban hierarchy system（S）and city primacy ratio（R）,removing 31 countries of S=1,at last using hierarchical cluster and SOFM to reveal the world pattern of national urban hierarchy system.The result shos,that the world pattern of national urban hierarchy system can be divided into 6types：the highermedium grade balance,the medium grade balance,the primary grade balance,the primary-medium grade unbalance,the primary grade unbalance and the primary primacy.Classification results show that the classification effect is good,and it can reflect the similarities and differences between the nations using.