Spatial Identification And Evolution Analysis Of Urban Functions Based On Big Data

After the reform and opening up,China’s rapid social and economic development,the process of high-speed urbanization,many cities face the problem of renewal and reconfiguration of internal functional space.At this time,China’s cities urgently need to change the original rough and single sprawl development mode to a more refined and high-quality stock potential mining.Urban functional space is an important basic component of a city.Identifying urban functions,analyzing urban functional space structure and urban functional mix can reflect the actual situation of urban development,provide basic data for scientific and reasonable urban functional planning proposals,and achieve the goal of promoting the diversified development of urban functions.By using spatial big data such as POI,it can effectively solve the problems of difficult access to traditional data,high research cost and poor timeliness,and study urban space in depth and carry out fine analysis under the scale of fine granularity.Based on the crawled Gao De POI data of Zhengzhou City in 2012,2017 and 2022,this study explores the evolution of the functional space of Zhengzhou City between 2012 and 2022 by studying three aspects: identification of urban functional units,spatial characteristics of urban functional elements,and intensity and mix of functional elements,with the following main research contents:(1)Using a 500m×500m grid as the basic research unit,based on the POI data of 2012,2017 and 2022,a new method based on the combination of the number of POI points and the footprint of the represented elements is used to identify the urban functional units in Zhengzhou,and it is found that although the number of mixed functional units increases in Zhengzhou city in general during the10 years,the number of single functional units The number of single functional units is gradually smaller than that of mixed functional units,and the mix of urban functions develops in a more diversified direction,with the most commercial-business functional units,commercial-business-integrated service functional units,and commercial-business-residential living-integrated service functional units in 2012,and the most commercial-business-integrated service functional units in 2017,and in order to increase livability in 2022,commercial-business-residential living mixed functional units,commercial business-integrated service units,etc.,will continue to increase in 2022 in order to increase livability.(2)Three analysis methods,namely kernel density analysis,mean center,and standard deviation ellipse,were used to explore the characteristics of density clustering,center of gravity distribution,and spatial morphology of the six types of urban functional elements in Zhengzhou city: residential living,commercial and business,integrated services,industrial logistics,green space and leisure,and transportation hub in 2012,2017,and 2022.Among them,the transportation hub elements increase rapidly and gradually form a cluster area.(3)The locational entropy index was used to reflect the geographical concentration of six functional element types in 2012,2017 and 2022,and the information entropy model was used to describe the overall mix of urban functions in Zhengzhou in 2012,2017 and 2022,reflecting the development status of spatial units with both data.It is found that the old urban area within the third ring of Zhengzhou is more maturely developed from 2012 to 2022,and the old urban area is mainly a medium and high-mix area in 2012,which becomes a high-density area in 2017,and a small part of the old urban area decreases in mix in 2022,becoming a small part of medium and low mix and most of high mix.The spatial and temporal changes in the evolution of Zhengzhou city between 2012 and 2022 reflect a shift from a period of agglomeration toward the center of the old city to a pattern of suburban dispersion.(4)In response to the problems of concentration of Zhengzhou’s urban functional elements in the development of the old urban area,weakness of the peripheral areas,lack of regional supporting facilities,and incongruity between urban construction and traffic development,suggestions are made to improve the problems by constructing a reasonable and balanced spatial structure of urban functions,promoting reasonable functional mixing and integration of public services,creating a comprehensive transportation network,and shaping characteristic spaces with urban renewal as a grasp.