Research On Layout Evaluation And Optimization Strategy Of Urban Park Green Space In Hefei Based On POI Data

As an important part of creating a good urban environment,the construction of urban park green space not only undertakes the responsibility of improving the urban ecological environment,but also provides a place for residents to play,exercise and rest activities.In recent years,the construction of urban ecological civilization and green development has been put on a new height.As an indispensable part of urban ecological civilization construction,urban park green space has attracted the attention of all sectors of society.In the past,many well-received urban parks and urban park systems have been built with the intuition and accumulated experience of planners.However,traditional methods are often considered from the perspective of supply.Under the background of the current smart city construction and the rapid development of big data,urban residents ’ lifestyles and recreation needs can be better collected through big data services,and are gradually applied in the field of planning.How to rely on effective data to analyze the recreation needs of urban residents,how to use quantitative analysis from the supply side and demand side two angles,the park green space service level and urban residents ’ recreation needs are combined to analyze and evaluate whether it can reach the balance of supply and demand,is a new idea for optimizing the layout of urban park green space.As one of the categories of big data,POI data not only has advantages in the number of data,but also has high timeliness and richness,and can effectively reflect population activities.As a data source,POI data can provide objective and effective quantitative support for planning and design.In this study,the urban area of Hefei is taken as the research scope,and a set of park green space layout evaluation model is established based on the summary of relevant research methods at home and abroad.The model is based on POI data,with quantitative and qualitative analysis as the main line,and the supply and demand balance of urban park green space as the foothold.Firstly,using kernel density estimation analysis,standard deviation ellipse analysis,nearest neighbor distance analysis to analyze the distribution characteristics of urban park green space in Hefei,including the overall distribution characteristics and spatial distribution agglomeration characteristics.Secondly,using service pressure index and park green space demand analysis to evaluate the fairness of urban park green space layout in Hefei from the existing supply and demand.Finally,the service pressure of the existing green space and the residents ’ demand evaluation of the park green space are comprehensively analyzed and field research is carried out.The existing problems are summarized,and the options for adding various types of parks in the future are given.The corresponding optimization strategies are put forward in order to provide certain scientific basis for the planning evaluation and adjustment and optimization of the urban park green space system.The main conclusions are as follows :(1)Selecting POI data as the support of quantitative analysis of this study,using POI data to analyze the distribution characteristics,service pressure and demand evaluation of urban park green space,and the results are visually presented through visualization.(2)The urban park green space in Hefei is characterized by the spatial imbalance distribution of ‘ multi-center and group ’.In addition,Hefei urban park green space at 0.01 level in the northwest-southeast direction distribution is more intensive.(3)The allocation of park green space resources in some areas of Hefei urban area is unreasonable.Urban parks with 10-50 hectares and more than 50 hectares bear greater service pressure than other types of parks.Parks with less than 2 hectares and 2-10 hectares have more service pressure concentrated in the first and second levels.Areas with higher pressure are less.The overall number of upstream parks and community parks is less and the distribution is uneven.(4)In the urban area of Hefei,the park demand is the highest in the boundary of the four districts,mainly concentrated in the old urban area.Several prominent high points are the inner ring area of the ring park,and the intersection area of the North First Loop and the Zhanxi Road.(5)The corresponding optimization strategies for the spatial layout of urban park green space in Hefei are put forward : constructing a more perfect urban park system,adding various types of parks when there are conditions for the addition of urban parks,and giving the options for the future addition of park green space;layout adjustment of park green space combined with public travel mode,public transport and urban public service facilities;upgrading the existing parks;provide more effective park green space for vulnerable groups.