Differentiation of urban-rural interface and its driving mechanism: A case study of Nanjing, China

The urban-rural interface is the frontier of urban expansion and rural development. Understanding the differentiation and driving mechanism of the urban-rural interface could help policy-makers mitigate negative impacts of development and promote integration through proper planning. Taking Nanjing as an example, this study provides new insights into the different types of urban-rural interfaces and what drives their. differentiation. We first built a conceptual framework to hypothesize how the urban-rural interface was differentiated. Based on multiple datasets, a two-step classification method (random forest model and k-medoids) and the multinomial logistic regression (MLR) model were then introduced to identify different urban-rural interfaces and explore influencing factors, respectively. The results show that 341 communities/villages were identified as belonging to the urban-rural interface, with 37 communities/villages as urban-dominant, 128 communities/ villages as intertwined, and 176 communities/villages as rural-dominant. Most mean values of land use, demographic, and socioeconomic characteristics decreased sequentially from urbandominant to intertwined and rural-dominant interfaces. MLR results indicated that transportation and economy were common drivers, while policy orientation, planning, and location accounted for the different urban-rural interfaces. In combination with the conceptual framework and additional investigations, this study concluded the driving mechanism of urban-rural interface differentiation in Nanjing. Specifically, the development of urban-dominant interface was mainly promoted by local governments; the development of intertwined interface was usually driven by complicated factors with the involvement of many stakeholders; policies facilitated by central/regional government accounted more for the development of rural-dominant interface. With the above analysis, this study further discussed the relationship between the urban-rural interface and planning system, and proposed differential development and management suggestions for the urban-rural interface.