Characteristics of Spatial Connection Based on Intercity Passenger Traffic Flow in Harbin-Changchun Urban Agglomeration, China

With the continuous improvement of transportation facilities and information networks, the obstruction of distance in geographic space has gradually weakened, and the hotspots of urban geography research have gradually changed from the previous city hierarchy to the characteristics of urban connections and networks. As the main carrier and manifestation of elements’ mobility such as people and material, traffic flow is of great significance for understanding the characteristics of spatial connection. In this paper, Harbin-Changchun agglomeration proposed by China's New Urbanization Plan (2014-2020) is taken as a research object. With the data of intercity passenger traffic flow including highway and railway passenger trips between 73 county-level spatial units in the research area, a traffic flow model is constructed to measure the intensity of spatial connection. Using social network analysis method, the characteristics of spatial connection of Harbin-Changchun urban agglomeration are analyzed, and the results are visualized with ArcGIS technique. The results show that the spatial connection of the Harbin-Changchun urban agglomeration based on traffic flow presents a distance attenuation effect that weakens in the directions of "Harbin-Daqing-Qiqihar-Mudanjiang" and "Changchun-Jilin-Tumen"; the direction of the connection clearly points to the Heilongjiang’s provincial capital Harbin and Jilin’s provincial capital Changchun, which proves that the agglomeration effect with Harbin and Changchun districts as the core is significant; the connection strength of Harbin or Changchun districts and other spatial units is the strongest, follow by Daqing, Qiqihar or Jilin districts and other spatial units. However, counties and cities in the border areas of Heilongjiang and Jilin provinces have the lowest connection strength with other counties and cities, indicating that there are obvious regional differences in the spatial connection level of the Harbin-Changchun urban agglomeration, and the connection nodes present a dual-core-edge hierarchical distribution. The research can provide support for the proposal of regionally coordinated sustainable development strategies of Harbin-Changchun urban agglomeration.