中文摘要：

幂次法则是普遍存在于自然科学和社会科学界的现象，而城市位序一规模法则是幂次法则在城市科学中的体现之一，然而特定城市规模分布一直缺乏完整的解释。本文尝试结合城市增长过程中土地开发行为的报酬递增规则与土地开发主体的风险认知行为，以城市增长的微观过程为切入视角模拟宏观城市聚落演化过程，进而探讨风险态度对城市聚落形态，尤其是对其规模分布的影响。研究结果表明：①即使城市聚落演化过程中存在多种风险态度，幂次法则在城市聚落的规模分布中仍保持着稳健性；②现实世界中城市聚落规模分布的变异和稳定可能来自城市主体风险态度的多样性。

英文摘要：

The power law is a phenomenon that can be widely observed in both natural and social environments, and rank-size rule of urban scale is an instance for the power law in urban science. This paper tries to integrate the increasing returns of land development and the risk perception of land developers into an urban growth model, which simulates the macroevolution of urban settlement systems based on microcosmic growth of single cities, and further reveal how risk attitudes of land developers affect the pattern, especially the size distribution of urban settlement systems. With the attraction effect controlled, the relationship between certain combination of risk attitudes and the size distribution of the generated urban settlement system can be explored. There are totally 76 treatments compared in our simulating experiment, consisting of 56 single-attitude treatments and 20 multi-attitudes treatments. The results suggest that： 1） the power law is pervasive in the size distributions of urban settlement systems regardless of land developers＇ various risk attitudes, indicating the robustness of this law, 2） the size distributions of urban settlement systems with different risk attitudes differ drastically from one another with regard to the degree of uniformity, probably corresponding to urban settlement systems with different endowment or at different stages in the real world, and 3） a phenomenon of ＂convergence＂ can be widely observed in multi-attitudes scenarios, implying cities with medium and small size may play an important role in the constancy of rank size distribution of urban settlement systems in real world.