Urban renewal simulation with spatial, economic and policy dynamics: The rent-gap theory-based model and the case study of Chongqing

Urban renewal has been an essential strategy for urban development in China. The decision to redevelop land in the process of urban renewal will help to optimize urban spatial layout, guide functional positioning, and improve the physical environment, to solve the urban land resource shortage problem and achieve sustainable development. This research aims to simulate the dynamic trend of land-use change by using the Cellular Automata (CA) model; with various complex settings, the actual urban renewal status, as well as three scenarios for future development, are simulated and analysed in the case study of Chongqing to assist and support stakeholders in making proper decisions for future urban planning. The study proposes a method to embed the rent gap theory, which states that when the value gap between the potential ground rent and actual ground rent is larger, the attractiveness of investing capital in land redevelopment is larger. In the process of CA simulation, the rent gap theory, as a transition rules of land-use change, can reflect the internal mechanism of urban development. When the location-based spatial characteristics are used, the macro-economic factors, such as GDP, interest rate and depreciation rates, can quantify the rent gap in the CA model. In addition, based on the background of China's "government-led" development, combined with the real situation, the endogenous and exogenous influencing factors of the policy are used as the quantitative factors of the rent gap theory and the second type of transition rule of land evolution, respectively, which can accurately reflect the urban development. The results show that the dynamics in the land redevelopment of Chongqing are well described by the model; additionally, the policy implications to manage the urban renewal are discussed in the research.