Researchers: Ying Long, Xun Li, Kang Wu, Dongfeng Yang, Wei Zhu, Xueliang Zhang, Zhigang Li, Gonghao Cui, He Huang, Jiangping Zhou, Hong Leng, Peng jiang, Helin Liu, Xingjian Liu, Xinyue Ye, Kai Zhou, He Li, Tingting Chen, Xiaodi Zheng, Yuanjing Zhang, Shuqi Gao, Xiaoxiang Yi, Yue Wang, Zhichong Zou, Xiangfeng Meng, Quanchuan Fu, Pingjun Sun （按参加顺序：龙瀛，李郇，吴康，杨东峰，朱玮，张学良，李志刚，崔功豪，黄鹤，周江评，冷红，姜鹏，刘合林，刘行健，叶信岳，周恺，李鹤，陈婷婷，郑晓笛，张远景，高舒琦， 衣霄翔，王月，邹志翀，孟祥凤，付泉川，孙平军）
Volunteers: Biao Tong, Nawei Wu, Yang Ju, Jie Zhang, Yiyun Sun.
Calling for more volunteers. Please address your CV and interest to Dr Long via email@example.com (志愿者召集中)
城市人口的收缩由来已久，德国政府资助项目（Shrinking Cities）已经证实，全球范围内人口超过100万的450个城市地区，总体上失去了其城市人口的十分之一。德国学者近几年进行了开创性的探讨（发表在Environment and Planning A/B上），以居住人口作为评价指标已成为共识。总体上，国际上发生城市收缩的原因，主要在于，（1）全球化背景下从制造业到服务业的经济转型，以及由此造成的劳动力结构性失业和产业资本外流；（2）其他影响因素还包括郊区化、战争、自然或人为灾害、老龄化或低生育率，以及东欧国家社会主义制度的瓦解等。
Many cities across particular areas in Europe and North America have a dwindling population, emerging vacant spaces, and the underuse of existing urban infrastructure (Haase et al., 2014). As one of the more prosperous urbanized countries in the world, China has witnessed an unprecedented active stage of urban expansion (see the Beijing City Lab Ranking 8 for details, http://www.beijingcitylab.com/ranking/), which also attracted extensive attention from academics (Deng et al., 2010).
Our previous study on mushing Jiedaos (the basic administrative unit of a city proper) indicates that urbanization in China often involves a significant political dimension. Largely rural settlements (eg, Zhen) could be accorded with the city status (eg, Jiedao) overnight by administrative power, which further accelerates the urban process (Wu et al., 2015).
Meanwhile, some large cities and inshore developed cities in East China have attracted huge numbers of migrants from rural areas and small cities during the last ten years. Vacant villages have been widely reported in the context of China (Long et al., 2012), while we observe a shrinking phenomenon at township and city levels.
For all the townships in mainland China, we estimated their population (residents not Hukou) based on the Population Censuses of China in 2000 and 2010, respectively. We found that 19,882 among all 39,007 townships were losing their population during 2000-2010, and the total area was 3.24 million km2, which covered almost about one third territories of China (Figure 1). Those shrinking townships are distributed in both rural and urban areas. Among them are 1,147 urban townships with a total area of 47,420 km2 in 367 cities.
Besides shrinking townships observed, we further identify 180 shrinking cities in China including one provincial capital city Urumqi, 40 prefectural-level cities and 139 county-level cities (Figure 1). In addition, we use a cartogram to reveal population density in 2010 at the prefectural level, based on which shrinking prefectures are mapped (Figure 2).
More work is needed to understand these shrinking localities, the reasons behind the population falls, and possible policy tools. Both decision makers and city planners are accustomed to the urban growth and population increasing in China. We hope that these featured graphics will inform them of our findings. In addition, we have established the Chinese shrinking city research network (http://www.beijingcitylab.com/projects-1/15-shrinking-cities/) for exploring this important issue via proposing necessary planning rules for shrinking cities.
Shrinking Cities: International Perspectives and Policy Implications (Google eBook)
Shrinking Cities: A Global Perspective (Google eBook)
澎湃新闻 Pengpai in Chinese：石岭小镇看东北
美国国家地理 National Geographic ：The young and lonely hearts of China’s shrinking cities
As the focus of urban planning in China converts from incremental planning to stock-based planning, researches concerning shrinking cities become increasingly important. Street being one of the basic elements of cities, the changes of spatial quality of it are essential to the evaluation of the changes of shrinking cities. This study uses street views from the Tencent Maps to evaluate the changes of quality of street space in the central districts of Qiqihar from 2013 to 2015. The research reveals that the quality of street space of Qiqihar is getting better while the rapid change of commercial real estate under residential buildings suggests a decline in economy. Based on this finding, the“Population-Economy-Space Decline Lagging Phenomenon”is proposed to illustrate the change mode of population, economy and spatial quality during the shrinking process of cities.
We have published a Springer book entitled "Shrinking Cities in China: The Other Facet of Urbanization". More information is available online at Springer (https://www.springer.com/us/book/9789811326455).
This book offers an essential introduction to the phenomenon of shrinking cities in China, highlighting several case studies, qualitative and quantitative methods, and planning responses. As an emerging topic in urbanizing China, cities experiencing population loss have begun attracting increasing attention. All chapters of the book were contributed by leading researchers on the subject in China. Richly illustrated with photographs for a better visual understanding of the topic, the book will benefit a broad readership, ranging from researchers and students of urban planning, urban geography, urban economics, urban sociology and urban design, to practitioners in the areas of urban planning and design.
Although there has been a rapid urbanization in China since the 1980s, the simultaneous urban shrinkage phenomenon has existed for a long time. The study of shrinking cities is particularly important for China as the current urban development has changed from physical expansion to built-up area improvement. After redefining what constitutes a city (what we term a natural city), we compared the adjusted nightlight intensity of National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) data between 2013 and 2016 to accurately identify shrinking cities throughout China. The results indicate that there are 2,862 redefined natural cities in China and that the total area reaches 53,275 km2, about 0.5% of the national territory. Based on this, we identified 798 shrinking cities with a total area of 13,839 km . After analyzing the relative position of shrinking cities and internal shrinking pixels in the geometric space, the morphological characteristics of shrinking cities were systematically classified into six patterns. The majority of shrinking cities belong to scatter shrinkage, central shrinkage, and local shrinkage; only 5% are complete shrinkage; the rest are unilateral shrinkage and peripheral shrinkage. In addition, six shrinkage causes were quantitatively classified and summarized by referring to multiple-source urban data and municipal yearbooks. To enrich the methodological system for urban shrinkage, the research provides a reminder of the need to consider the other side of urbanization (i.e., dissolution of social networks) and proposes appropriate strategies and policies to address shrinkage issues.
emergence of perforated shrinkage. This study could provide scientific evidence for micro management of urban development, optimization of land use pattern, improvement of urban livability, and conduct of urban planning and design in the context of urban shrinkage.
compact cities would help achieve SDG 11 in consideration of the new urban shrinking landscape with multisource data like CO2 emissions and points of interests (POIs).
You can click the image above or the LINK for more information regarding our UABB work, including a well-prepared video.
More details are available online at https://mp.weixin.qq.com/s/EJdROT3QtfEhfmv_JF5rMQ
Global gridded population dataset in 2020 and 2100 under SSP2 can be open accessed at
https://doi.org/10.6084/m9.fifigshare.19608594.v2. NC boundaries in 2020 can be accessed at https://doi.pangaea.de/10.1594/PANGAEA.905890 or http://www.geosimulation.cn/GlobalSSPsUrbanProduct.html.