Abstract: Urban expansion models are a useful tool for understanding urbanization process and have been given much attention. However, urban expansion is a complicated socioeconomic phenomenon that is affected by complex and volatile factors involving in great uncertainties. Most dynamic models focus on the interaction between the urban expansion and various influencing factors, and have continuously evolved for greater nuance and precision. However, accurately simulating the urban expansion process remains ambiguous. In this paper, we try to solve such uncertainties through a reversal process and view the urban expansion as a process in which the urban landscape competes with other landscapes for control by overcoming ecological resistance. We apply an innovative method based on the minimum cumulative resistance (MCR) model to construct an urban expansion ecological resistance (UEER) model and then to apply it to the urban expansion in Guangzhou. The results indicate that the ecological resistance surface generated by the UEER model reflects comprehensively the ecological resistance for the urban expansion and indicates spatial trends in the urban expansion. Thus it can be used as an effective model for the urban expansion and compensates for the inadequacies in most dynamic models that ignore ecological constraints to a certain extent. Compared with simulation results to the conventional MCRbased model, the simulation results from the UEER-based model are more realistic and accurately reflect ecological protection requirements. Based on the scale control of the urban expansion, simulation results better accord with the actual demand and reflect the land development policy. Considering the urban form and its relationship with ecological factors, all of the important ecological elements are preserved in the process of simulation. The ecological barriers act as ecological isolations, prevent the urban sprawl and result in the group urban form.

Key words: Guangzhou, urban expansion, model, ecological resistance surface, simulation