Study On Comprehensive Assessment Of Street Walking Environment With Double-level Space Units Of Urban Areas And Routes

A well street walking environment is not only about the image of the city,but also helps people to travel greenly,reduce the frequency of car use and reduce air pollution.In recent years,research on the quality of street walking environment has gradually increased,and the research on walking environment assessment provides a quantitative basis for improving urban space quality.However,because the factors affecting walking are extremely complicated,the research involves multiple subject areas.The single assessment method of walking environment has many limitations,and a comprehensive assessment method is urgently needed.Based on the results of multidisciplinary research,this dissertation combined the walking impact factors of urban areas with routes.A comprehensive assessment system for urban street walking environment based on double-level space units of areas and routes was constructed.In the double-level spatial units comprehensive assessment system,its index differentiation and combination organization reflects the hierarchical differences and transitions between urban planning and architecture.The space unit of areas reflects the spatial network properties of the urban walking environment.And the space unit of routes reflects the visual environment element attributes of the pedestrian.Therefore,the comprehensive index system with doublelevel spatial units of areas and routes could reflect the characteristics of the walking environment more diversified and strengthen the comprehensiveness of assessment.Further expand the spatial hierarchy of the walking environment assessment unit,and highlight the actual impact of the physical element characteristics on the pedestrians from the visual environment.Making the assessment of the quality of the walking environment more objective,it also provides new ideas for the quantitative study of the walking environment.The main contents of this dissertation and related research results include:1.Focusing on the 4 characteristics of the current Chinese urban space walking environment,it penetrates the urban the meso-scale spatial features of urban areas with the micro-scale spatial features of urban routes in 4 dimensions including spatial scale and street network,human space and urban life,street type and balance between pedestrians and vehicles,human visual environment and design details.Refining the technical framework and theoretical basis for comprehensive assessment of street walking environment from the perspective of urban design to objectively examining and accurately analyzing urban space and walking environment.2.After repeated screening and verification with corresponding optimization,the index system and indicators'measurement method of the "Double-level Space Units Comprehensive Assessment System" were set up.It contains 32 indicators in four criteria layers including morphological structure,functional layout,traffic environment and visual detail.It formed a multi-dimensional,diversified research system.3.The index measurement technology and data structure constructed in this dissertation highlighted the quantification and measurement of physical attribute,and 27 indicators achieved the continuous variables measurement methods.The study found that the continuous variable greatly improved the accuracy of the assessment scores,which could optimize the score composition and strengthen the distinguishing ability of the samples.It highlighted the scientific and authentic advantages of objective physical attribute data in the process of information aggregation.4.The use of urban mapping data,street view image data,spatial element observation statistics and other advanced information technology platforms to collect data to achieved accurate measurement of physical attribute indicators.A scientific and objective measurement techniques and methods were introduced and validated.The system composition of the assessment results and the scores of the indicators indicated that the objective measurement and objective assessment could effectively link the urban design practice work,and could control and guide the design of the walking environment.At present,the objective measure is a breakthrough in deepening the study corelates walking.It has social and economic benefits with expanding the phsical indicators and the objective measure technology.5.The comprehensive assessment technology was introduced,and the model of"Comprehensive Assessment of Street Walking Environment with Double-Level Space Units in Urban Areas and Routes" was established.The entropy weight method of objective empowerment was used to empower the walking environment indicators.The difference of two assessment mechanism was analyze between entropy weight method and analytic hierarchy process.On this basis,the subjective and objective combination weighting method "entropyanalytic hierarchy process" was used to optimize the structure of the mathematical model,and explored the innovative technology of the comprehensive assessment method of street walking environment using fusion information between subjective and objective.Using mathematical analysis technology,a systematic assessment method of walking environment was established.Its system construction and standards setting are the advancement of the study of walking environmental analysis theory to urban development and practical application.6.Through the comprehensive assessment model constructed in this dissertation,the quality of the walking environment of 12 streets with different characteristics and different property in Wuhan was assessed.The objective analysis method and the perception questionnaire were applied to verify the assessment results of the objective entropy weight method.The results show that these three have well consistency.(1)According to the results,the systematic comparison analysis and comprehensive sorting were carried out.Then the corresponding optimization strategies were proposed.(2)According to the comprehensive value,12 streets in Wuhan were divided into three categories:The first category of comprehensive assessment score exceeds 0.48,and the four criteria are scored in a balanced and high excellent quality of the street walking environment.These streets were designed controlling by urban design project,with perfect functions,rich environmental elements and excellent space quality.The second is around 0.4,and the four criteria could be high or low.These streets has obvious defects in individual factors,and they were generally constructed in earlier time.Its street space continues the early design concept,lacks urban design elements,humanities and places.The third is lower than 0.30,and the scores of the four criteria are relatively low.Due to the defects of the walking environment,levels of quality differences were caused.These differences are the subject of urban design rectification and darning.(3)The index contribution analysis is a combination of the entropy weight method of objective weighting and the analytic hierarchy process of subjective weighting,and it was used to comprehensively analyze the indicators' contribution to the walking environment.The result found that 14 indicators have a prominent contribution to the quality of urban street walking environment.In the designing progress,the spatial elements of the 14 indicators should be designed in a focused manner.7.By calculating the index information entropy value,the discrimination degree of each indicator was obtained,and the characteristics of each assessment object in the system were reflected objectively.It effectively and accurately located the metrics that can be optimized in the quality of the walking environment.And the objective weighting method shows more complete objectivity.An analysis system consisting of a finite set of assessment objects,each element contained has a clear certainty,and its weight is information inherent to the sample indicator value,and thus exhibits a wider adaptability.8.The research carried out the correlation and integration analysis of indicators based on the quantitative characteristics of the walking environment.(1)Based on the indicator values of 12 streets in Wuhan,the correlation research was carried out according to the four dimensions of the index criteria layer.By calculating the indicators correlation coefficient of each criterion layer,the relationship between the physical elements of the urban street walking environment was found out.(2)Based on the data measured in this dissertation,according to the 4 dimensions of the index criteria layer,the 32 indicators were subjected to dimensionality reduction analysis,and the relationship of the factors were used for index integration research.Through the factor analysis model,the potential variables of the underlying indicators of each assessment criterion layer were found out,and a total of 12 rotating components were obtained.They explained the characteristics of the physical elements of the street walking environment and the composition of the indicators.The results were consistent with and confirmed the rationality and scientificity of the index setting system.