Abstract: A model based on nonlinear dynamics is proposed to characterize the urbanization process of China. Then a universal model of urbanization process is presented by combining the above mentioned model with the United Notions' model, which can be used to describe the United States' urbanization process. The time series data of urbanization level in China from 1949 to 2000 is employed to verify the new model, and the result is satisfying. The model bears an analogy with the Lotka-Volterra model of predator prey ecological interaction, one of the most widely discussed examples of a non linear system in two dimensions. The difference lies in that one of the parameters is zero. Extensions of such models should help us understand Holland's question: why predator prey ecological interaction exhibit strong oscillations, whereas the interactions that form a city are typically more stable.

Key words: urbanization, spatial dynamics, Lotka-Volterra model

摘要： 提出了刻画中国城市化过程的非线性动力学模型，并将该模型与描述美国城市化进程的模型在形式上进行了统一，得到城市化非线性动力学的一般模型。借助中国1949?2000年的城乡人口数据从经验上证实了模型的有效性，同时给出美国模型的数据拟合过程作为参照。中国的城市化动力学模型与生态学的Lotka-Volterra模型同构，但参数不同，由此可以解释城市演化的Holland问题。另一方面，中国的城市化动力学模型与西方的城市化模型参数性质不同，由此可以揭示中国城市化进程中存在的问题和优化的方向。

关键词: 城市化, 空间动力学, Lotka-Volterra模型