The Change of Urban Population Spatial Structure of Nanjing, 1982-2007 Based on ESDA, Density Function and GIS

The study of urban spatial structure has long been of interest to those concerned with urban studies and spatial data analysis. Urban population spatial structure is an important component of urban spatial structure. This paper explores the change of urban population structure based on methods of exploring spatial data analysis (ESDA), population density function, and GIS and aims to discover the features and change of urban population structure of Nanjing City sine 1980'. The paper organizes as three sections. In the first section, we reviewed the methods of the urban population spatial structure. The sub-centre of a city as an important indicator of urban spatial structure is often identified using threshold value, ESDA and population density function based on GIS technology. In the second section, we analyzed the features and change of urban population spatial structure using the methods reviewed above. Firstly, we pictured the features of urban population spatial structure using threshold value and GIS. Secondly, we carried out an ESDA on population density in order to identify possible population patterns of spatial heterogeneity and spatial autocorrelation in the study area. Next, we validated the result of ESDA using population density function. The third section summarized the key findings in this paper. The application of this procedure showed that the pattern of population structure of Nanjing City was single center in 1982; sub-center distribution appeared in 1990; and the pattern of sub-center strengthened in 2000. The multi-centric distribution of urban population was discovered through the ESDA analysis in 2007. In addition, through the modeling of urban population density, the polycentric population density function has been found to perform better than the mono-centric one, which demonstrated that the polycentric pattern of population density distribution has being emerged in Nanjing City during the period from 1982 to 2007.