A temporally cyclic growth model of urban spatial morphology in China: Evidence from Kunming Metropolis

• Published in: Urban studies (Edinburgh, Scotland) Scotland), 2019-06, Vol.56 (8), p.1533-1553
• Main Authors: Wu, Qiyan, Cheng, Jianquan
• Format: Article
• Language: English
• Subjects: Case studies; Density; Economic models; Economic restructuring; Evolution; Expansion; Growth models; Indexes; Indicators; Infill; Infrastructure; Investment; Investments; Land; Mathematical morphology; Morphology; Public works; Redevelopment; Socioeconomic factors; Spatial data; Temporal variations; Urban areas; Urban development; Urban growth; Urban sprawl; Urbanization
• ISSN: 0042-0980; 1360-063X
• DOI: 10.1177/0042098018767614

Rapid urbanisation and complexity of political-economic transition in China has brought about continuous and remarkable changes of urban morphology over the past decades, which were driven by a mixture of spatial, social-economic and institutional forces. Understanding such urban morphological evolution requires new mixed evidence and holistic perspectives. In this paper, it is argued that two dominant types of urban growth in China: low-density expansion and high-density infill, might be driven by different forces at different stages. To interpret the processes of urban development, two easy-to-understand morphological indicators: ‘expansion-induced investment density index’ (EID) and ‘infill-induced investment density index’ (IID), are defined to measure the investment density per unit of developed land and used to compare the morphological changes between different phases in a long period by integrating spatial and socio-economic data. The temporal variation of these indicators suggests a cyclic growth model (CGM), which means the periodic switch between low-density expansion and high-density infill. Using Kunming metropolis as a case study, this paper has confirmed that its urban morphological evolution from 1950 to 2014 was periodically and reciprocally driven by a set of vis-á-vis dualistic dynamics, in which low-density expansion is led by pro-growth infrastructure-oriented public investment, while the high-density infill is activated by collective and rational actions of individual enterprises and their economic behaviours. It is concluded that the confirmed CGM model, together with two morphological indicators, offers a new holistic perspective and method to easily and integrally interpret urban morphological evolution and accordingly has potential theoretical implications for reasonably understanding the urbanisation in China. 中国的快速城市化和政治经济转型的复杂性在过去几十年引发了城市形态的持续而显着变化，这些变化是由空间，社会经济和制度力量的混合驱动的。了解这种城市形态的演变需要新的混合证据和整体观点。本文认为，中国城市增长的两种主要类型：低密度扩张和高密度填充，可能受不同阶段不同力量的驱动。为了解释城市发展的过程，我们定义了两个易于理解的形态指标：“扩张诱导投资密度指数”（EID）和“填充诱导投资密度指数”（IID），以衡量单位土地开发投资密度。我们还使用这两个指标，通过整合空间和社会经济数据，来比较在长期中不同阶段之间的形态变化。这些指标的时间变化显示了一种循环增长模型（CGM），这意味着低密度扩张和高密度填充之间的周期性转换。以昆明大都市作为案例研究，本文证实了1950年到2014年昆明的城市形态演变是由一系列形成对比的二元动力推动的，这两种动力周期性地交替，并且相互作用。其中，低密度扩张由以增长为导向的公共基础设施投资引领，而高密度填充则由个体企业的集体理性行为及其经济行为推动。我们得出的结论是，确认的CGM模型连同两个形态指标提供了一个新的整体视角和方法，可以很好地、整合地解释城市形态演变，因此对合理理解中国的城市化具有潜在的理论意义。