Impacts Of Subway Construction Mode On Urban Vitality Of Central Business District

Since the end of last century,Chinese cities have entered the era of subway construction.Central business district is the key functional area of urban planning to create urban vitality.What kind of mode to introduce subway construction is very important for the cultivation of CBD urban vitality.Firstly,this study constructs subway construction mode from three dimensions: construction sequence,connection type and layout mode.The construction sequence is divided into two modes: filling mode and guiding mode.The former is to introduce Metro when the old CBD is updated,and the latter is to plan to drive the development of new CBD with Metro as the guide.The connection type is divided into different modes according to whether the underground is connected between stations and whether the station is connected with the Metro property.The above model reflects the difference of Metro land use integration within the scope of station area.The subway layout mode rises to the overall level of CBD,and the mode is divided by the density of stations and the diversity of connection types.Secondly,for the description of urban vitality,this study measures the heat of vitality by pedestrian volume,identifies the types of vitality by K-means clustering of pedestrian and spatial elements,and uses social network analysis method to increase the measurement of spatial interaction potential.Then,this study takes Guangzhou gold mine CBD(filling type)and Tianhe North CBD(guiding type)as cases,and carries out research from local and global spatial scales.In the local scale,the subway station area is taken as the research scope,and each section of street is taken as the analysis unit.The correlation analysis and linear regression methods are used to analyze the influence and difference of subway construction mode on the station area vitality.In the global scale,the whole CBD is taken as the research scope,and the plot is taken as the analysis unit.The linear regression and network community discovery methods are used to analyze the subway construction mode on the CBD global vitality impact and differences.Firstly,it is found that subway has a positive pulling effect on the vitality and heat of the station area,but the pulling effect is affected by the construction mode,and the order of the strength is in the order of guiding connected station group,guiding connected isolated station,guiding unconnected isolated station and filling unconnected isolated station;at the same time,the permeability of street interface and the centrality of street network affect the station area activity Distribution of heat and force.Second,the station group has an absolute advantage in the heat and type of cultivating the vitality of the station area and the overall situation;the cultivation of the urban vitality of isolated stations is affected by the connection type,the higher the connection degree between stations and between stations and the Metro property,the higher the heat and type of vitality.Thirdly,from the perspective of layout,the high-density and multi type composite subway construction mode is conducive to cultivating higher vitality and more abundant vitality types,and the urban planning can better explain the spatial distribution characteristics of CBD vitality by enabling spatial interaction.It can be seen that urban planning can create a more dynamic CBD by optimizing the integration of subway and land use and improving the potential of spatial interaction,which has reference value and practical significance for urban planning practice.