Spatial Delimitation of the Urban-Rural Fringe Based on POI and Nighttime Light Data: A Case Study of Wuhan City

Objectives: The boundary identification of urban-rural fringe is the basic work of urban-rural fine planning and governance, plays an important role in promoting the sustainable use of land, urban-rural integration and other processes. The purpose of this study is to solve the problems of single data source selection, difficulty in data acquisition, low temporal and spatial resolution in the past recognition of urban-rural fringe. Methods: Taking Wuhan as an example, this study uses the breakpoint analysis method to obtain the boundary of urban-rural fringe. Land use structure information entropy, NDVI and population density data are used to verify and compare the delineation results, and field visits and analysis are conducted for typical regions. Results: 1)NPP&POI can integrate the characteristics of difference in facility type, light intensity and resolution between POI and nighttime light, and has higher accuracy and timeliness compared with the boundary of urban-rural fringe identified by nighttime light, population density and other data alone. 2) Compared with land use, landscape and other data, NPP&POI can better represent the vitality of urban and rural development. It can quantitatively identify the potential urban and rural central areas and multi-layer structures. This result has reference significance for the research of urban and rural infrastructure allocation, industrial division, ecological function division, etc. 3) The second mutation rule of NPP&POI in urban and rural space confirms that the urban-rural fringe exists objectively as a regional entity generated in the process of urban expansion, providing empirical support for the theory of urban-rural ternary structure.