Research On TOD Station Area Evaluation For Mega-city

With the rapid development of urbanization and motorization in China,"big city disease" has become the main factor restricting the social and economic development of cities in China.However,in recent years,TOD mode(transits)has been widely used-Oriented development(public transport oriented urban development)is regarded by many planning and decisionmakers as an important grasp to solve the problem of supply and demand in big cities,and it is used as the basis for urban development strategy research.However,in the application practice of localization,because the implementation effect is not ideal,there is an urgent need for a set of TOD station evaluation index system for mega cities to optimize and guide the completed projects.In addition,it is also necessary to identify the spatial heterogeneity and importance of sites in the whole network,so as to make targeted policies for different types of sites.Firstly,this paper interprets the definition,origin,development practice and other basic concepts of TOD in detail through literature tracking method.By comparing many excellent experiences at home and abroad,it summarizes the aspects that need to be improved in TOD mode in China;Then,through combing the TOD evaluation literature,this paper makes a comparative analysis of the current evaluation research methods and index selection methods at home and abroad,finds out the shortcomings,and selects the node site model as the main evaluation research method of this paper;Next,according to the purpose of this paper,the concept of city scale,station scale and core area scale is defined;Referring to a variety of theoretical systems,six objectives and criteria of the index system are determined;Based on the objective criteria,four guiding index screening principles are formulated,and the station area index system is constructed by combining Delphi expert consultation method;Then,based on the node site evaluation model of 5D principle,this paper makes a qualitative classification evaluation of Beijing rail stations in 2019.A four step cycle inspection process is constructed to verify the applicability of the index system;Because the original model can not determine the partition threshold,this paper chooses K-means ++ The algorithm performs quantitative clustering and selects the contour coefficient to determine the number of clusters;Using nodes at the same time-The classification threshold was determined by the comprehensive mean value of the location;Compared with the existing research results,it is found that the current clustering evaluation method is difficult to reflect the spatial heterogeneity and importance of the site,and it needs to introduce the macro level analysis index.Finally,the macro network centrality is introduced to expand the node place model.The complex network method can be used to measure the spatial heterogeneity and network importance,and four kinds of centrality are the key indicators to evaluate the spatial characteristics of complex networks;Using the open source software gephi to calculate the centrality index of Beijing rail network,and analyze the spatial characteristics of four types of centrality.Finally,three macro centrality indexes are introduced to form a macro micro twolevel clustering method.Then,the cluster evaluation of Beijing Rail Station area is carried out,and the differences between the two types of micro clustering spatial characteristics and target criteria are analyzed the development suggestions are put forward from two aspects of the station,This paper considers that the introduction of macro network centrality index and macro micro two-layer clustering method is an effective means for TOD station evaluation in mega cities.At the same time,it is suggested that megacities should establish a station area classification standard based on the node site model,and carry out layout planning and updating according to local conditions according to the evaluation level of stations and the importance of line network.