行政边界对城市群城市用地空间扩张的影响——基于京津冀城市群的实证研究

作为静态的抽象地理要素,行政边界如何影响城市用地的空间扩张过程?以城市群为研究对象,从理论的角度出发,构造符合中国城市群发展历程的行政边界效应阶段模型,并根据城市群发育过程中行政边界对城市用地空间扩张的影响,将其分为四个阶段：隐形阶段、异化阶段、疏导阶段和消融阶段,分析不同阶段城市群城市用地扩张的空间特征和动力机制。研究以京津冀城市群为实证案例,采用趋同分析和β回归方程测度不同类型行政边界对城市用地扩张的边界效应。研究表明：行政级别跨度越大,边界效应越大,城市间城市用地扩张规模的差距也越大;行政边界对城市用地空间扩张的影响具有长期性和累积性的特点,时间越长,边界对城市用地扩张的影响效应越显著。为突破行政边界制约、合理划定城市开发边界、实现城市群城市用地理性扩张提供理论支撑和政策建议。

The influence of administrative boundary on the spatial expansion of urban land: A case study of Beijing-Tianjin-Hebei urban agglomeration

As the static and abstract geographic elements, its is a puzzle that how administrative boundaries affect the process of the urban land expansion. Based on the empirical research of Beijing-Tianjin-Hebei urban agglomeration and evolution theory of the regional spatial structure, we build the model of administrative border effects on the urban land expansion of different development periods of China's urban agglomerations. According to the developed model, we divide the process of urban land expansion into four phases, namely, the invisible stage, the dissimilation stage, the persuation stage and the disappearing stage. Different phases have different characteristics. In the first stage, the spatial distribution of urban land is in the low level state of equilibrium; After that, the urban land in growth pole areas expands rapidly in the dissimilation stage. Then, urban land in cities around growth pole become the rapid expansion areas in the third stage. In the disappearing stage, the border only plays a crucial role in the symbol of different administrative divisions, and cities in the urban agglomerations become a comprehensive organism. Then the research of the spatial characteristics and dynamic mechanism of urban land expansion of the urban agglomeration is carried out in our study. We introduce the conditional convergence analysis and the β regression equation into measuring the border effect of the urban land expansion measurements in the case of Beijing-Tianjin-Hebei urban agglomeration. According to the administrative level of different cities, the boundaries are divided into class A, class B, class C and class D. Border effect is measured in different time scales, including 20 years, 10 years and 5 years. It shows that: the greater the administrative level gap between two cities, the larger the border effect, and so there is the scale gap of the urban land expansion between two cities; the influence of border effect on urban land expansion is a long process, the longer it takes, the more significant the border effect is. The research will contribute to the theoretical support and policy recommendations in breaking the restriction of boundaries, delimiting the city development boundary and realizing the rational expansion of urban land.