The evolving process of the land urbanization bubble: Evidence from Hangzhou, China

A significant cause of economic recession and environmental change that has attracted the extensive attention of researchers and policy-makers worldwide is the land urbanization bubble (LUB) – a rapid and catastrophic growth and decline in urban development fueled by a mixture of misplaced exuberance and speculation. It is also an important topic for sustainable urban development and urban renewal, and is of particular interest to China, as one of the countries with the largest amount of urban land, most drastic change, and most prominent land urbanization conflicts in the world. This study analyzes the characteristics and presence of dynamic change in LUBs during China's urbanization process through a case study of the changing space-time rules in Hangzhou in Zhejiang province over the years 2004, 2007, 2010, 2015, and 2020. Based on a literature review and analysis of the mechanism driving Hangzhou's LUBs, we design a method for their classification and measurement. This reveals the existence of an overall 18.24 km² LUB in 2010 and a predicted 40.62 km² LUB in 2020. Locally, the Jianggan and Yuhang districts are expected to have a higher LUB risk by 2020, the Bingjiang and Xiaoshan districts a medium risk, the Shangcheng and Xiacheng districts a low risk, and the Xihu district having no LUB risk. Finally, three policy recommendations are proposed in consideration of Hangzhou's economic development and land use characteristics, comprising (1) reducing LUBs by promoting intensive urban expansion, (2) reducing the possibility of LUBs by building a market-oriented control system for construction land expansion, and (3) the dynamic control of LUB risks by differential regulation of the expansion of urban construction land.