Research On Urban Spatial Interaction Of Wuhan City Based On Taxi Trajectory Data

A city is a complex system in perpetual motion,and its internal material elements cannot be independent of the system.That is to say,all the areas and regions in a city are bound to interact with each other through the flow of people,materials and information,that is,the spatial interaction.On the one hand,the geographical conditions and historical background of the city will affect the formation of spatial interaction;on the other hand,the spatial interaction between regions can reflect the social and economic layout of the city.In this important period of urbanization transformation,it is the theoretical and scientific basis for the future new-type urbanization construction to deeply understand the interactive and the structural characteristics of the city.It is also of great significance to the planning of Urban Economy and development.Based on the monthly taxi trajectory data of Wuhan in 2014,this paper extracts the passenger-carrying trajectories,and constructs the Wuhan Urban Spatial Interactive Network with the blocks as nodes and the tracks between the blocks as edges.Combined with the function attribute of block unit,Urban Spatial Interactive Network Based is analyzed through the theory of complex network.The main research contents and conclusions are as follows:(1)A Two-step Function Zone Identification Algorithm based on POIIn this paper,the traditional method of urban functional area identification based on POI is improved.The recognition process is divided into two steps.First,single functional areas are identified according to the density ratio of POI,and then the cluster analysis of POI density vector is carried out for the complex areas with mixed functions.The result shows that we can get a more precise and detailed classification of functional areas,which lays a foundation for the follow-up research on the relationship between spatial interaction and functional attributes of unit.(2)Research on Urban Spatial Interactive Network based on network centrality.The index of centrality in complex network theory is used to evaluate and analyze the urban spatial interaction network as a whole,and a comprehensive evaluation index of importance is constructed based on these basic attributes.Through these indicators,it can find out the key nodes which play an important role in the network and analyze the status and influence of the regions with different functionality.The results show that the importance of nodes in network is mainly influenced by their geographical location and functional attributes.The important railway stations and the comprehensive areas dominated by medical services are the key nodes of the urban population flow,and their spatial interactions constitute the basic framework of the network.(3)Community structure discovery of Urban Spatial Interactive NetworkThis paper makes a comprehensive analysis of the functional composition,internal interaction and external interaction characteristics of each community to classify different types of communities and interaction modes,and reveals the multi-central spatial interaction structure in Wuhan.The results show that there are differences between the community boundaries and the original administrative territorial entity of Wuhan.The population density,economic development and geographical conditions are the reasons for the differences.Each community,because of its geographical location,internal function composition,shows different interactive features.In general,the "three main,three deputies,multi-node" spatial interactive structure is presented in Wuhan city.The Two-step Function Zone Identification Algorithm based on POI proposed in this paper can further identify the areas with fuzzy function attributes and obtain more detailed classification results.It has theoretical and practical value for understanding the distribution and interaction characteristics of function zones.The results of the research on spatial interaction network in wuhan city reveal the characteristics of urban interaction structure and regional agglomeration,which can provide support for urban planning and relevant government decision.