Research On Spatial Structure Identification And Distribution Characteristics Of Urban Functional Areas Based On POI Data

With the accelerated urbanization process,urban development has entered a critical stage,but a series of urban problems have also emerged.Scientific analysis of urban spatial structure characteristics is of great significance in solving urbanization problems and reasonably allocating urban space and resources.In recent years,with the development of big data technology,the use of POI data for the identification and analysis of urban spatial structures has gradually become a research hotspot.Based on the POI data and OSM road network data of the six districts in Tianjin,this research investigates the identification results and distribution characteristics of single/mixed functional areas and integrated functional central areas in the city to explore the characteristics of urban spatial structure and propose optimization measures.The main research contents and results are as follows:Firstly,use ArcGIS software to unify OSM data and POI data into the WGS-84 coordinate system,achieving the fusion of multi-source data.Filter,deduplicate,and reclassify the POI data of AMap,dividing it into six categories: residential,commercial,green and square,industrial,public management and public services,and transportation facilities.Using the OSM road network data that completed topology error modification to generate road spaces and remove them,the six districts in Tianjin were divided into 1960 block research units.Secondly,select an appropriate search radius to conduct kernel density estimation on the reclassified city’s functional POI data,and the distribution of functional core density shows a gradual dispersion from the center to the periphery.Using the multi-density spatial statistical method to introduce two indicators,public awareness,and spatial area characteristics,assign weights to POI data,and construct an urban functional area recognition model to divide urban functional areas.The identification results and distribution characteristics of functional areas are:commercial areas with a single function,public management,and public service areas are the most widely distributed,and many areas are mixed with multiple functions.The confusion matrix is introduced to evaluate and identify the results,and the overall accuracy of the urban functional area division is 79.44%,reaching a high level of consistency.Thirdly,Based on kernel density estimation,the principal component analysis method is used to integrate the core density of various functions of the city,and an contour tree is constructed to extract the urban comprehensive functional center area and explore the urban multi-center structure.The recognition results and distribution characteristics of the comprehensive functional central area are as follows: a total of 8comprehensive functional central areas have been extracted,presenting a multi-center distribution pattern in space,with the largest central area located in Heping District.Comparing the recognition results with the actual situation of the six districts in Tianjin in the Amap,it was found that the accuracy was relatively high.Finally,In response to the problems of an unsatisfactory urban living environment,incomplete urban transportation network,and imbalanced regional functional spatial structure in the six districts of Tianjin,the spatial structure of the six districts in Tianjin can be further optimized through strategies such as promoting coordinated development of residential spaces,strengthening the convenient connectivity of urban transportation,rational planning of urban functional layout,and fully leveraging the regulatory role of planning policies.