Measurement Of Urban Vitality And Analysis Of Influencing Factors

In the context of rapid urbanization,urban population expansion,traffic congestion,poor environmental quality and other problems are becoming more and more common.Studying the mechanism of vitality creation is helpful to improve the level and efficiency of urban construction management and promote the sustainable development of the city,which is of great significance to urban planning,design,construction and operation and maintenance management.In this paper,the main urban area of Nanchang city as the research area,based on POI data,OSM road network data,Baidu thermal map data,building vector data and other multi-source data to study and analyze the vitality of the city.Firstly,the main urban area of Nanchang is divided into block units,and the function types of each block are identified.Then,the vitality intensity measurement model,vitality standard deviation model and vitality pole identification model are constructed to characterize the vitality of the city.Secondly,the paper analyzes the spatial distribution of urban vitality in the main urban area of Nanchang city,and analyzes the evolution difference of vitality from two time dimensions: the whole day of different characteristic days(three types of days)and different time periods within a day.On this basis,the differences of urban vitality between residential blocks and commercial blocks in time and space dimension are analyzed.Thirdly,based on the existing literature and the factors that create urban vitality,this paper constructs the index system of influencing factors of urban vitality.Based on the quantitative results of each index,this paper uses the geographic detector model and Pearson correlation analysis to study the differences between the overall influencing mechanism of urban vitality and the influencing factors of typical functional areas.The main research results are as follows:(1)Urban block segmentation and block function identification: the study area contains a total of 762 independent blocks,304 blocks with single function,356 blocks with mixed function and 99 blocks without function.(2)Spatial distribution of urban vitality: Generally speaking,the intensity of urban vitality spreads from the central area of Nanchang city to the peripheral area,showing a trend of gradual decline.The areas with high urban vitality intensity tend to promote the vitality of the surrounding blocks and make them show the pattern of flaky distribution.In addition,a large number of mixed blocks are often gathered.The area of the blocks is small,reflecting the characteristics of high road network density.The distribution of standard deviation of urban vitality is similar to that of vitality intensity,and the two show a certain positive correlation.The hot spots of urban vitality are mainly distributed in large areas near the axis on both sides of Xiangshan North Road,while the cold spots of urban vitality are scattered in the edge of the study area.(3)Evolution characteristics of urban vitality over time: By analyzing the difference of heat area of different grades on June 3,2022(festival),June 7,2022(working day)and June12,2022(weekend),the proportion of high heat and low heat area on working day is higher than the corresponding proportion on weekend and festival.The area proportion of ordinary and general heat on weekends and festivals is slightly larger than that on working days.The area proportion of high heat activity changes relatively gently on working days,while the corresponding area proportion of low heat activity changes sharply and accounts for a relatively high proportion on working days and weekends,but has little change on festivals.The proportion of common area increases and decreases repeatedly in festivals and weekends,with peaks occurring several times,while changes are relatively gentle in working days.(4)Analysis of influencing mechanism of urban vitality: All secondary factors detected by geographical detector factors are the main influencing factors of urban vitality.According to the interactive detection,the degree of economic construction,regional functional characteristics,residents’ psychological feelings,the degree of traffic construction and the degree of commercial construction are the main factors affecting the vitality of the city.From high to low,the order of interpretation degree of each secondary index for urban vitality is service construction degree,functional density or cultural construction degree,land development degree,building density,public transportation convenience or commercial construction degree,functional mixing degree of surrounding blocks,greening degree,global integration degree of traffic,functional diversity index,compactness degree,sub-dimension and hydrophilicity degree.There are some differences in the influencing mechanism of urban vitality in different typical spatial functions.The common feature of urban vitality of residential and commercial areas is that the vitality level of both areas is positively correlated with the functional density factor of the block and the construction degree factor of the block service industry.The corresponding vitality of residential category is also highly correlated with the degree of cultural construction,the convenience of public transportation,and the degree of commercial construction.It is weakly correlated with the compactness,fractal dimension,functional diversity index,and greening index,and the correlation degree with other indicators is different according to the functional characteristics of the block.However,the relationship between commercial areas and compactness,sub-dimension and functional diversity index is weak,and other factors are affected by specific conditions.The main innovation points of this paper are as follows: First,this paper takes block as the basic unit of research,considering the characteristics of urban vitality in space dimension and time dimension;This paper studies the influence of spatial function on urban vitality,and analyzes the characteristics of urban vitality of typical functional blocks.Secondly,this paper combines a variety of open source big data to analyze the distribution and evolution characteristics of urban vitality from the two dimensions of time and space.Finally,when studying the mechanism of building urban vitality,various indicators such as environmental comfort and residents’ psychological feelings are added to further improve the existing research index system.