Research On The Evaluation And Influencing Factors Of Street Space Quality In Karst Mountain Cities Based On Street Urbanism

In recent years,with the continuous advancement of China ’ s urbanization process,the continuous impact of new technologies and new methods,the scale of domestic cities has been expanding rapidly and the density is increasing.At the same time,street space has become a forgotten urban public space.The lack of vitality,quality decline and lack of characteristics of streets have gradually emerged in the process of rapid urban construction.The improvement of urban public space quality has become an important part of modern urban construction and an important factor affecting urban sustainable development.On the basis of the continuous evolution and application of new technologies and the intersection of various disciplines,urban problems have new research perspectives and solutions.Under this background,this paper took the street urbanism as the research idea,with the street space of karst mountainous city as the research object and the central city of Guiyang as a case.Through the mining and analysis of big data,this paper evaluated the street space quality of the central city of Guiyang from the theoretical and empirical aspects and analyzed the internal and external influencing factors.First of all,in the theoretical research,the relevant theories of urban street space quality and urban planning big data are summarized and combed,and the related concepts are defined.At the same time,the research object has been clarified.Seventeen evaluation indexes are selected by using the Delphi method to evaluate the street space quality of the central urban area of Guiyang,and the weight of each index is assigned through the analytic hierarchy process.Subsequently,in the empirical study,the road network data,construction data,format POI data and streetscape image data of the central urban area of Guiyang are obtained by legal means on the network,and the basic database of quantitative research on street space quality of the central urban area of Guiyang is established.The relevant indicators of street space quality are calculated and summarized by means of spatial syntax under s DNA,kernel density analysis method,and streetscape image element recognition,so as to quantitatively evaluate the street space quality of the central urban area of Guiyang and analyze the distribution characteristics of space quality.Finally,the external influencing factors of street space in the central urban area of Guiyang are explored,including urban location,urban construction scale,historical culture and natural landscape.At the same time,the correlation between internal influencing factors and street space quality is calculated by SPSS software,and the internal and external influencing mechanisms are analyzed.Five street composition modes are proposed,including commuting oriented street,public service oriented street,daily life oriented street,landscape comfort oriented street and comprehensive oriented street.The representative streets in the central urban area of Guiyang are selected for case analysis.The main conclusions of the study are as follows :(1)This paper found that the current research on the quality of street space in karst mountainous cities was not prominent in quantity and degree.Under the environment of new data and new technology,this paper determined the research object and research idea.Through theoretical and empirical analysis,17 evaluation indexes were selected from the four dimensions of network accessibility,functional diversity,spatial comfort and street safety to construct the evaluation system.And through legal meaned to obtain urban road network data,urban construction data,format POI data and Baidu street picture data,a quantitative analysis database is established for the evaluation index system.(2)In this paper,the indicators were calculated and visualized through the Arcgis platform,and it was found that the spatial quality of streets in the central urban area of Guiyang presents a’ trapezoidal’ distribution trend in the numerical distribution.The number of low-quality and medium-quality streets is similar,and the number of high-quality streets is small.The numerical distribution of medium-quality streets is relatively average.The farther the average center value is,the less the distribution is.On the spatial distribution,it shows the spatial distribution characteristics of ’ single-core multi-center axis radiation ’ and ’ west is better than east,north is higher than south ’.(3)This paper analyzed the influencing factors and influencing mechanism of street space quality from both internal and external aspects.The external influencing factors include urban location,urban construction scale,history and culture,and natural landscape,which mainly affect the quality of street space from three aspects,namely,the degree of central aggregation,the degree of new and old cities,and the diversity of business forms.Among the internal factors,service function density,sky openness and other indicators are strongly correlated with street space quality,and street network intermediary centrality,traffic facilities richness and other indicators are weakly correlated with street space quality.(4)In this paper,by integrating the relationship between the various influencing factors,summed up the commuter factors,service function factors,space comfort factors and street safety factors of these four street space quality factors.On this basis,the street space is divided into commuting-oriented streets,public service-oriented streets,daily life-oriented streets,landscape-comfort-oriented streets and comprehensive-oriented streets according to the combination of relevant guidance.Some streets in the central urban area of Guiyang are selected for empirical analysis,and optimization strategies are put forward for improving the spatial quality of each oriented street.Overall,under the idea of street urbanism,this paper establishes the evaluation method of urban street space quality from the four dimensions of network accessibility,functional diversity,spatial comfort and street safety through urban space big data,format POI data and Baidu street picture data.This paper aims to quantitatively analyze the street space of karst mountainous cities by means of data enhancement,and supplement the research in this field.At the same time,it is hoped that this study can provide reference and contribute to the urban research of Guiyang.