城市紧凑性测度指标研究及典型城市分析——以南京、苏州建设用地紧凑度为例

量化表征城市紧凑性是当前地理学界和规划领域共同关注的热点问题,明确紧凑性指标反映的实际意义与适用范围,成为构建测度体系的关键.当前已有众多研究提出数量相当可观的量化指标,本文结合国内外城市紧凑性定量研究进展,根据表征紧凑内涵的不同将其归纳为形状、规模、密度、结构、功能和过程6 类,分析了不同类型指标的适用范围,并以结构类指标为例,采用南京和苏州的实际建设用地数据,根据指标自身稳定特性识别的实用性和局限性,达到评判和筛选指标的目的.结果显示：指标能有效指示建设用地的实际空间结构特征;4 个指标受尺度变化的影响不强烈,具有良好的应用性能,其中Gini 系数和Moran’s I 在应用中,前提条件局限小,适用广泛;而连续度和向心度较直观,但在进行城市比较研究时限制条件较多.该研究结果能够为城市紧凑性量化研究提供一定的借鉴,并指导城市规划与管理政策制定.

Urban compactness index and its application:Compactness of built-up areasin Nanjing and Suzhou

As compact cities are being promoted in sustainable development policies in many countries, including the developing regions, research on urban compactness is still hampered by the lack of consensus on its meaning and negligence of the applicability of the indicators for compactness measurement. In this paper, we aim to clarify the confusions in the selection of indicators and their applications. Firstly, we introduced recent studies on the measurement of compactness from six different perspectives: shape, size, density, structure, function and process, and discussed the applicability of each individual indicator. Then, by analyzing the practicability and limitation of specific structural indicators based on their stability in reaction to the change of grain size, we evaluated the existing methods for the selection of evaluation indicators. Sample results from the cities of Nanjing and Suzhou showed that four selected indicators don't have so strong reactions to scale change, which qualifies them for reliable measurements. These results serve as a reference to the measurement of compact cities and provide guidance for urban planning and decision-making of management policies.