Identification And Optimization Of Xi’an Urban Land Use Function Based On POI Data

The fast-paced industrialization procedure and the enlargement of urban & rural construction space have driven tremendous changes in China’s urban and rural structures,specifically,the urbanization rate of China’s resident population in 2019 is about 3.4 times higher than in1978,while the urban population is 4.9 times higher than in 1978.More than 40 years of "compressed " urbanization process has brought many problems to China’s urban development.Since the 19 th Party Congress,urban construction has begun to enter a new period of pursuing high-quality development.In the face of the comprehensive execution of National Land and Spatial Planning,identifying and delineating the dominant functions of different urban land uses is an important basis for determining the future development direction of cities,as well as an important basis for building a territorial spatial planning data system and upgrading the smooth development of territorial spatial planning.Based on the properties and status of Xi’an city,this article raises a research framework for identifying,verifying,analyzing and evaluating the current urban land use functions based on big data through a combination of big data mining and spatial analysis.The results of the current land use functions in the central city of Xi’an were obtained by reclassifying the POI data according to the "Guidelines for Land Use Classification of Land and Sea Use for Land Spatial Survey,Planning and Use Control(for Trial Implementation)" and identifying and labeling the dominant functions of the land parcels with machine learning methods,and proposing corresponding optimization strategies based on them.The main research contents and findings of this paper are described below in brief:(1)Integration and processing of urban big data.By pre-processing POI data and OSM electronic map data,unifying the coordinate system and sorting and integrating the road network data,2568 plot units are generated in the central urban areas of Xi’an based on the status blocks as the smallest research units for the identification of the status quo urban land functions.(2)Identification of nowaday land use functions in the central urban areas of Xi’an.The area and functional influence of the selected sites were weighted to the POI data,and the TF-IDF statistical method was used to construct a practical system for identifying the functions of the sites in the central city of Xi’an,and to complete the identification of the current site functions.The overall accuracy reached 79.44%.(3)Spatial traits of land utilization in the central urban areas of Xi’an.The identification of the current land use functions shows that the central city areas of Xi’an is dominated by residential and commercial functions;Lianhu District,Xincheng District and Beilin District have a high land use mixture;Gaoxin District,Qujiang New District and Longshouyuan have developed into secondary urban functional groups.(4)Optimization strategies of land use functions in the central city of Xi’an.In view of the problems in the functional organization,spatial formula and mixed land use in the central urban areas,the following suggestions are proposed: to carry out urban renewal in the central city,upgrade various substructure facilities and shape a well-run green landscape system;to tone up the construction and development of each group based on the pattern of "one core and many groups";to formulate corresponding standards for the phenomenon of mixed land use.The corresponding normative standards should be formulated.