Study On Urban Boundary Based On Human Activities In Shanghai

Urban boundary is an important foundation of cognitive city information.The definition of city boundaries is important for urban studies.With the expansion of urban space,different urban boundaries of the same city will get different statistical results of urban activities.It is also the basis for the layout of urban spatial structure and urban function partitions.Therefore,only by defining the boundary of a city can we objectively and accurately analyze a series of urban problems.In the context of rapid urbanization,many times the actual development scope of the city cannot coincide with the administrative region.With the advances in information technology,people's life is in constant change.As the main body of information technology,human activities have a great impact on the change of urban spatial structure,and human settlements have become an important perspective of urban space.As a result,it is of great significance to identify the urban entity boundary and the urban virtual boundary and compare them to analyze the actual development of urban space.In the past,the definition of urban boundary was mainly based on the analysis of traditional data such as population density statistics,economic data,remote sensing data.However,due to the limitations of traditional data collection methods,it is difficult to complete both the research scope and the precision,and it is difficult to accurately reflect the current situation of dynamic development.With the advent of the era of big data,big data makes up for the shortcomings of traditional data with the advantages of large amount,convenient access,fast update and strong periodicity,which greatly improves the timeliness of urban boundary research.Taking Shanghai as an example,this paper summarizes the temporal and spatial distribution characteristics of human settlement activities,and divides the urban entity boundary and activity boundary based on POI data and mobile signaling data.Based on the above research,the main conclusions are as follows:(1)The human settlement activities in Shanghai are characterized by centripetal in the daytime and centrifugal at night.(2)The human activities are divided into three types: living activities,employment activities and consumption leisure activities.The structure of residential activity circle is obvious,showing the distribution law of the central area,the suburb area and the suburb area decreasing in turn.The employment activities have the trend of centripetal agglomeration.The overall distribution trend of consumption and leisure activities tends to cluster in the central area of the city and spread in the periphery of the city,which reflects that there is acertain degree of "counter centralization" trend in the leisure space of Shanghai.On the whole,the urban activity boundary presents the spatial form of long east-west and narrow north-south.This includes the central city and surrounding areas,Songjiang New City,Qingpu new town,Jiading new town,Minhang new town and Baoshan new town,Shanghai harbor comprehensive economic development zone and Waigaoqiao exempt-zone.(4)The coverage area of urban entity boundary is smaller than that of central urban area,including Huangpu District,Jing'an District,Hongkou District,Zhabei District,southwest part of Yangpu District,north part of Xuhui District,east part of Changning District,south part of Putuo District,Pudong District.