The Research On Quantitative Evaluation Of Street Spatial Quality In Commercial Blocks Based On Multi-source Data

With the acceleration of urbanization in our country,the transformation of the life style of the people,the urban development from the past incremental development to the stock development.However,in this process,a series of problems in urban public space are gradually exposed,such as traffic congestion,spatial quality decline,spatial vitality decline,low place identity and other problems.Streets are an important part of urban public space,and various urban problems are constantly reflected in the streets.Currently,commercial blocks,as an important public sphere of urban development and construction,bear the diversified needs of residents such as shopping,eating and entertainment.However,in the process of urban development,Its internal street space is also faced with traffic congestion,single functional forms,destruction of space quality and vitality decline and other problems,it is necessary to carry out reasonable optimization of its street space.In recent years,with the development of information technology,new data including multi-source data as well as new tools and methods are used to study the street space quality in commercial blocks,which brings new opportunities to improve the street space quality,enhance its spatial vitality and promote the development of commercial blocks.Based on this,this paper takes the street space quality in commercial blocks as the research object.Firstly,based on relevant theories and practices at home and abroad,from the perspective of space and people,two dimensions of objective street environment composition and users’ subjective psychological perception are determined,and the influencing factors of street space quality in commercial blocks are sorted out under the dual dimensions.Six elements of accessibility,morphological characteristics,functionality,safety,comfort and identity were determined.By referring to the existing research results,the quantitative evaluation indexes of street space quality in 12 commercial blocks were determined,including street accessibility,street width to height ratio,functional mixing degree,motor vehicle interference degree and street green vision rate.The quantitative evaluation system of street space quality in commercial blocks was completed.Subsequently,multi-source big data combined with field research data was used to determine the quantitative methods of each index by using image semantic segmentation and Arc Gis spatial analysis methods.In addition,the weights of each evaluation index were determined by combining with AHP,which was used for the subsequent comprehensive quantitative evaluation of street space quality in commercial blocks.Secondly,Zhengzhou Erqi Square commercial block is selected for the application research of the evaluation system,and the street space quality in the study area is quantified.Descriptive analysis and evaluation are carried out on the quantitative results,and the comprehensive quantitative evaluation results of the street space quality are obtained by combining the weights of each evaluation index determined in the previous paper.On this basis,the quantitative evaluation results are summarized.It is found that most of the street Spaces in the region have problems such as low walking accessibility,low mixing degree of business forms and functions,too high interference of motor vehicles,low street green vision rate,and some of the street space vitality decline,low degree of crowd clustering and color richness,lack of street identity and other problems,and the causes of these problems are analyzed.At the same time,the correlation analysis between the quantified value of the evaluation index and the comprehensive quantified value of the street spatial quality in the region is carried out.It is concluded that the interference degree of motor vehicles and the accessibility of walking are the most important indicators affecting the street spatial quality in the study area,and reasonable control of these two indicators can significantly improve the street spatial quality in the study area.In addition,the quality of street space can be effectively improved by improving single or multiple indicators such as street green sight rate,sky visibility and color richness.Finally,based on the overall quantitative evaluation results and correlation analysis results,combined with the relevant optimization principles,the optimization strategy of street space quality under the objective environment composition dimension and subjective psychological perception dimension is proposed respectively,in order to improve the street space quality in Erqi Square commercial block.It also provides some ideas and references for the improvement of street space quality of commercial blocks in Zhengzhou and other cities.