Research On Urban Tram Design And Evaluation Based On Niche Theory

With the rapid development of urbanization and motorization,China is vigorously promoting the construction of eco-cities,new-type towns and green transportation systems.With its green and low carbon characteristics,urban tram has gradually become the key public transportation mode in many cities in China.Urban tram,however,as a new urban rail transit,the reality of it for the coordination of urban ecological still exist,such as noise pollution,low operation efficiency,loss of cultural function,fuzzy function orientation and other issues.The main reason is that the existing urban trams lack the systematic consideration and insufficient attention to passenger perception,so that the development of trams in China lack reasonable functional positioning and systematic research at all levels,from the direction of the urban ecological development.Niche theory,as a powerful tool to explain the relationship between individuals and the whole in ecology,can be introduced into the study of urban tram to guide the design of urban tram at system level.Therefore,the basic theoretical framework of urban tram niche was established by reviewing the related research on urban tram,sorting out the basic theories of natural niche,and studying the relationship between urban tram and its ecological environment,which defined the definition,constituent elements,structural characteristics and evolution mechanism of urban tram niche.The evaluation mechanism and factors of urban tram were proposed,including the city tram niche suitability,overlapping and separation,width,situational and potential difference,expansion and compression and build strategy.The holistic design framework of urban tram from the perspective of niche was proposed,and the ecological niche index system of urban tram was established for passenger perception and the holistic design evaluation model of urban tram based on niche was constructed using cloud theory.The empirical study of Chengdu tram line 2 was carried out,and the ways and strategies for the niche improvement of Chengdu tram line 2 were discussed,which the feasibility of the method and model was verified.The paper focuses on the following issues:(1)The basic theory of urban tram niche was constructed.The definition,constituent elements,structure characteristics and evolution mechanism of urban tram niche were put forward,by studing the relationship between urban tram and its hosting environment,that is,urban compound ecological system,urban traffic subsystem,urban public transport community.The theoretical tools of urban tram ecological niche was discussed and the role and strategy of urban tram construction were proposed.(2)The generation approach of urban tram design scheme from the perspective of ecological niche was proposed.The evolvement law of realized niche search in the full-cycle design of urban tram was studied based on Markov Chain principle.Each link of the whole cycle will be taken as feedback points,and the key factors of the niche will be monitored and evaluated continuously,so as to form the design scheme of repeat trial-and-error and multiple verification,and provide scientific and reasonable guidance for the design of urban tram.Among them,continuous monitoring and evaluation are the basis of the design process.The niche evaluation provides technical support for the monitoring and evaluation in the urban tram design.(3)The urban tram niche index system driven by passenger perception was constructed.The urban tram’s ecological environment is complicated,affected by many factors.According to the existing research results,text content analysis is adopted to extract the key elements and design the questionnaire for passenger perception.Exploratory factor analysis was carried out on the survey data from passengers,the function of urban tram niche was identified,including technology,vehicles,environment and culture image,operation management and economic for five types of rule layer,36 indicators layer dimensions of ecological factors.The urban tram niche index system was established,and the weight of each index was determined by combination weighting method.(4)The evaluation model of urban tram design based on niche was estalished.Based on the natural niche theory,the basic models for evaluating the width,overlap degree and suitability of urban tram niche were constructed respectively.Face on the uncertainty of the urban tram niche,the urban tram cloud evaluation model of niche breadth,niche overlap degree and niche suitability were put forward,combined with the advantage of the cloud theory and TOPSIS method.Finally,the evaluation model of urban tram design based on niche was proposed.(5)A case study.The selection of chengdu trams rong line 2 as an example,examine the city trams niche and evaluation method is practical,proposed the chengdu rong tram line 2 of the optimization strategy,including bus structure optimization,suitable for transfer to preferential policy,lights,cultural image promotion,organization operation optimization,etc.,The effectiveness of the optimization scheme was verified based on Markov chain.It has a wide application prospect.In theory,the design and evaluation of urban tram driven by passenger perception from the perspective of niche provide a systematic and holistic perspective for the study of urban tram,and broaden the depth and breadth of the study of urban tram.In practice,the ecological constraints was put into the research of urban tram,for improving urban tram research and development.It has important significance in optimizing the design of the urban tram,improving the tram ability of survival and development of the city and promoting the overall ascension of urban ecological system and changing to the green economic development model.