Modelling urban expansion guided by land ecological suitability: A case study of Changzhou City, China

Rapid urban expansion usually leads to the change of land use pattern and poses a severe threat to land resources with high ecological value, it is necessary to model the impact of urban development on surrounding environment. The aim of our study is to construct an effective model of simulating urban expansion with protecting ecological land, which could provide a decision-making reference for sustainable development of the city and promote the rational distribution of land resources. In this paper, we proposed an urban expansion model based on land ecological suitability (LES). The proposed model involves using the minimum cumulative resistance (MCR) method to evaluate and visualize the land ecological suitability of the study area. Next, the random forest (RF) algorithm and cellular automaton (CA) are combined to construct an RF-CA to simulate future growth of urban land. As a case study, the RF-CA was used to simulate the distribution of urban land in Changzhou City, eastern China in 2020. The LES evaluation results were then used as the basis of optimizing urban expansion and restrained the excessive sprawl of the city, which could reduce encroachment on land resources such as waterbody and farmland, thereby increasing the ecosystem services value (ESV) by 50.24 million RMB(1 RMB = 0.15 US dollar). It was observed that our model could reduce the spatial conflict between urban expansion and ecological land protection effectively. Therefore, we believe that the results of our case study can contribute to more reasonable urban planning.