Spatial Balance Of Park Green Space In Zhengzhou Based On Kernel Density Two-Step Floating Catchment Area Method

Urban park green space(PGS)is an important spatial indicator of urban public services,whose distribution plays an irreplaceable role in improving the environment,meeting residential recreation needs and improving residents' quality of life.With the rapid expansion of urban scale,there is a strong demand for construction land,which poses a serious threat to urban green land.In addition,the unbalanced distribution of urban PGS leads to the obvious "supply-demand dislocation" and "space mismatch" between the supply of urban PGS service facilities and residents' recreational demand.How to distinguish the spatial imbalance of urban PGS is the basis of optimizing the allocation of urban PGS in the new era.Under the background of old city reconstruction and urban renewal,the evaluation of urban PGS balance is helpful to clarify the spatial distribution law of urban PGS,and find out the problems existing in the planning and layout of urban PGS,and ultimately promote the city to a higher level of development.In this study,we selected 2494 residential areas and 106 PGSs in Zhengzhou's 4th ring region(including 1st-4th ring region)as an empirical case study.We integrated the location and navigation services of a web map API with a kernel density two-step floating catchment area method(KD2SFCA)to establish a refined evaluation framework for spatial balance of urban public service facilities.This paper compares and analyses the spatial balance of community,district and municipal PGS under various traffic modes(walking,bicycle,public transit,and private car).In addition,we identify imbalanced areas where resources are scarce.The research conclusions are as follows:(1)Under the four modes of travel,the number of opportunities for residents to choose PGS varies greatly in space,which is manifested by the attenuation from urban central area to peripheral area.In addition,from the perspective of travel time cost,under the four modes of transportation,the time cost from residential area to community PGS is the lowest,and the municipal PGS is the highest.(2)We find that there are significant differences in the spatial balance of community PGS,district PGS and municipal PGS under the four modes of travel.Specifically,the spatial balance of district PGS is highest,followed by that of community PGS.The overall spatial balance of urban municipal PGS is the lowest,under the walking mode,87.28% of the residents are in the state of "no supply",while under the bicycle and private car modes,more than 70.53% of the residents are in the state of "over supply".(3)Comprehensive evaluation results of spatial balance of all kinds of PGS,the overall spatial balance of urban PGS in Zhengzhou is poor.In the 1st and 2nd ring regions,the supply and demand balance is the best under the mode of public,but only 2.89% and 18.67% residents are in the "supply and demand balance" state respectively.In the 3rd and 4th ring regions,the supply and demand balance is the best under the mode of bicycle,but only 21.17% and 7.63% residents are in the "supply and demand balance" state respectively.(4)Under the four modes of travel,there is a big difference in the spatial imbalance of of community PGS,district PGS and municipal PGS.Specifically,the imbalance between the supply and demand of community PGS is the most serious under the walking mode.Among them,53.11% of residents are in the state of "no supply",while 32.10% are in the state of "over supply".In addition,under the walking mode,the higher the grade PGS of arrival,the higher the proportion of the population with "no supply".Under the bicycle and private car mode,the higher the grade PGS of arrival,the higher the proportion of population with "shortage of supply" and "over supply".The contribution of this study lies in relying on the web map API platform,meanwhile,real-time navigation data and the population data of building scale are included in the accessibility measurement model,thus more accurate and objectively evaluates the spatial balance of urban PGS.The research results can provide a scientific basis for more adequate and reasonable allocation of urban PGS and the optimization of transportation facilities.This work can also provide a more fine-scaled research perspective for studying urban infrastructure spatial balance.