城市蔓延的多维度思考

半个多世纪以来，城市蔓延引起了广泛关注，取得了显著的研究进展，但也存在一些不足。本文就城市蔓延的内涵界定、测度方法、动力机制及中国大城市空间扩张的特殊性进行讨论与辨析，认为：城市蔓延是指那种盲目而无计划的、分散而非连续性的、用地功能单一且低密度的、过度依赖机动化出行且导致人地关系日趋紧张的不可持续的城市空间扩展模式；具有复杂性、阶段性、区域性、相对性等特点；是经济因素、制度因素、政策因素、技术因素、规划因素、社会因素、文化心理因素或行为因素等综合作用的结果；城市蔓延是过度郊区化的表征，是与特定的时空条件相联系的，需要从中心城区与郊区互动演进的视角来考察；中国大城市的交通拥堵和空气污染问题正在从城市中心向郊区扩展，新一轮城市规划必须对此给予足够的重视。

MULTI-DIMENSIONAL REFLECTIONS OF URBAN SPRAWL

More than half a century, the urban sprawl has attracted extensive attention of scholars from different disciplines,the significant researchprogress hasmade,however, there are still some shortages. In this paper, the authors discuss the connotation definition, measurement methods, dynamic mechanismof urban sprawl,and discriminatethe particularity of spatial expansion of Chinese big cities. The authors hold that city spread refers to the blind and unplanned, dispersed and discontinuous, the single-function and low density, over-reliance on motorized traveling and an increasingly tensepopulation and landrelationship,unsustainable model of urban spatial extension, which has the characteristics of complexity, stage, regional, and relativity, and is the result of comprehensive action such as economic, institutional, policy, technical, planning, social, cultural and psychological factors. City spread is characterized by excessive suburbanization, is associated with specific temporal-spatial conditions, and needs to be examined from interactive evolution perspective between the city center and suburbs.Traffic congestion and air pollution in China's big cities is not only anurban rather than a suburb problem, a new urban planning must pay enough attention to this.