Research On Public Traffic Spatial Distribution Characteristic And Accessibility Of Xi’an Ancient City Based On GIS

In recent years,with the increase of the number of urban motor vehicle ownership,urban transport systems are increasingly unable to meet the demand of growing traffic.The popularization of cars will make the urban society and economy suffers the impact of the deterioration of traffic.Therefore,the public transport focusing on mobility is the fundamental solution in metropolitan area.The development of public traffic system directly related to the improvement of living standards and the efficiency of urban development.In this paper,the geographic information system(GIS)technology is used to analyze the spatial characteristics and the comprehensive measure of accessibility of public transport system in Xi’an ancient city.On the theoretical study,the paper recommends the introduction of geographic information systems and the concept and application of accessibility combined with domestic and foreign research.On this basis,the public transportation geodatabase of Xi’an is established based on the basic data of urban public transport and the external environment data,and the fields and definitions of the feature class in the database are described,which provide the data foundation for the later analysis.In the aspect of public spatial characteristics analysis,the basic situation of the study area and the current situation of traffic development are introduced.Secondly,the site average station distance,site coverage,the line length,the non-linear coefficient,and the line network density indicators are selected from the urban public transport system planning index system to analyze and evaluate the current situation of public transportation network in Xi’an ancient city.We can reach the density of public transportation network slightly lower,the site average station distance slightly higher and repetition coefficient too high is the main problem in the public transportation network.In terms of public transport accessibility,based on the comparison of five kinds of accessibility models,a combination model of public transportation system is proposed,and the calculation process of accessibility based on GIS is established,including data processing and traffic impedance calculation,accessibility value calculation,and visualization of results.Finally,this paper analyzes the spatial characteristics and time reachability of the public transport network,and puts forward the tentative suggestions on the optimization of the public transport system in the ancient city of Xi’an,with a view to providing decision-making reference for the urban public transport planning and the sustainable development of urban traffic.Taking the ancient city of Xi’an as an example,it analyzes the influence of the urban public transportation system on the different spatial forms of the urban area,and can realize the automatic measure of the reachability level of each spatial location,so as to realize the purpose of guiding the urban planning work.