Exploring transformation of small and medium-sized historical towns in China with network analysis and user-generated open data

Abstract

Ye ZHANG1, Xiangya XIE2, Jie ZHANG2 1 Department of Architecture, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117566 2 School of Architecture, Tsinghua University, Beijing100084, P. R. China E-mail: akizy@nus.edu.sg; xiexy15@mails.tsinghua.edu.cn; zjzhangjie@tinsghua.edu.cn Keywords (3-5): urban transformation, small and medium-sized historical Chinese cities, big data While an increasing number of research on transformation and conservation of historical areas of major Chinese cities have been witnessed in recent years (e.g. Whitehand et al, 2011; Whitehand et al 2014; Whitehand et al 2016, among many others), endeavours to studying more ordinary and small and medium-sized historical towns in China are rare. In the near future, those historical towns will be confronted with a new wave of developments, given that urbanisation of small and medium-sized cities and towns is high on China’s 13th five-year plan (2016-2020). This will pose a serious challenge to the conservation of their already vulnerable traditional urban fabric. This study aims to develop an accurate description of the transformation of built form, in particular street and block patterns, of the small and medium-sized historical towns, and how this is associated with the change of spatial distribution of urban activities. A total number of 36 towns in Zhejiang province, China are selected as case studies. Transformation of the urban fabric is examined based on cartographical maps of different historical periods using combined methods of urban network analysis and field survey. A large amount of user-generated geo-referenced open data, such as social media reviews, point-of-interest mapping, microblogs and night time illumination maps, are harnessed to produce a detailed description of urban activity patterns, of which the relationships to the transformation of urban form are investigated using multi-variate regression models. The results show how basic built form parameters such as spatial integration, between-ness centrality, block size and block depth can effectively and accurately describe the transformation of the small and medium-sized historical towns and how the formal changes are linked to the geographical shift of different urban activities. In which ways the findings can inform decision making in urban conservation practice to better address the tension between conservation and developments is discussed at the end.References: Whitehand Jeremy WR, Gu Kai, and Whitehand Susan M. (2011). "Fringe belts and socioeconomic change in China." Environment and Planning B: Planning and Design 38 (1):41-60 Whitehand Jeremy WR, Gu Kai, Conzen Michael P, and Whitehand Susan M. (2014). "The typological process and the morphological period: a cross-cultural assessment." Environment and Planning B: Planning and Design 41 (3):512-533. Whitehand Jeremy WR, Conzen Michael P, and Gu Kai. 2016. "Plan analysis of historical cities: a Sino-European comparison." Urban Morphology 20 (2):139-158.