Study On Spatial Structure Of Metropolitan Area Influenced Of Urban Railway Transit Network

The metropolitan area(MA)is the economic engine of the region and even the country.For China's mega-cities,the mode of motorized transportation is changing from road traffic to rail transit,and the mechanism of spatial organization is undergoing significant changes.At the same time,the prolonged travel time in the MA has also seriously affected people's happiness in life.From the experience of international development,improving the urban rail transit network and optimizing the spatial structure of land to improve the matching efficiency between economic factors such as population and industry and transportation are important ways to enhance the spatial efficiency of MA.This article starts with the above background of reality and theory.First of all,the thesis combs the definition of MA at home and abroad,and the space range is about 3500 km~2-120,000 km~2.It is considered that MA as a spatial and geographical form of urban development in advanced stage,and its essence still possesses the characteristics of urban attributes.Secondly,on the basis of combing the development history of metropolitan areas in foreign countries and summarizing the general laws,this paper establishes a benchmark for evaluating China's problems,and systematically combs and identifies the main problems existing in the synchronous development of metropolitan space evolution and rail transit in China.It is found that in the same period,the problems in the urban rail network planning and construction of similar-scale cities in China are highly convergent,and the causes are analyzed from the aspects of spatial development planning,rail network planning and their coordinated development..Thirdly,the dissertation studies the spatial evolution of Tokyo MA,Seoul MA and Paris MA in depth.It mainly studies the characteristics of population growth history and distribution,the spatial distribution of employment and the characteristics of the center system.It is considered that the population growth in MA is obviously characterized by"intractable".Under the support of rapid rail transit facilities,the separation of distance of employment and residences is a universal law.At the same time,the paper studies the optimization strategy of spatial structure of three MA from land space and rail transit.Fourthly,this paper systematically analyses the similarities and differences of the spatial structure of metropolitan areas at home and abroad,studies its formation mechanism,and holds that accessibility is an important spatial influencing factor.The center of metropolitan area is closely related to track loop and urban express rail.There are obvious network structure efficiency mechanism,network layout structure mechanism,travel behavior mechanism and organization mechanism.Fifthly,the dissertation analyzes the general characteristics and differences of spatial structure of MA at home and abroad systematically,analyzes its internal reasons,and holds that mega-cities in China establish the spatial structure of metro-oriented is inevitable.The dissertation puts forward MA has 3 to 4 level center systems.The structure of MA is divided into two types according to the spatial distance between CAZ and emerging CBD,and the corresponding spatial structure modes are respectively constructed.The spatial structure mode pays more attention to the role of urban rapid rail in spatial organization,and concerns about rapid rail on the supporting role between CAZ,CBD with large-scale hubs.Sixthly,The paper takes Xi'an metropolitan area as an example,puts forward Xi'an MA land space and rail transit optimization strategy.ArcGIS was used to evaluate the travel time distribution features and accessibility characteristics before and after the optimization of rail transit network.It is found new metropolitan rapid rail effectively supports the urban space development and the positioning of north-south axis line that metro line 2 lays,obviously improves the accessibility in the range of the city cent.The entire MA rail network accessibility is 1.12 times than that before optimization.