Evaluation Of Urban Green Space In Environmental And Social Benefits Based On Quantitative Analysis

A series of urban diseases occur during the urbanization process,bringing more and more attention to the improvement of urban environment.Urban green space(UGS)plays an important role in creating livable urban space and maintaining the well-being of urban residents due to its diverse environmental and social benefits.Scientific measurement and evaluation of UGS is of great significance for urban fine management.Especially with the improvement of remote sensing spatial resolution,a variety of high-resolution remote sensing data supported the more detailed studies of UGS.However,previous studies mostly evaluated UGS from a single perspective,and the degree of quantification and refinement was not enough.This study focused on constructing UGS evaluation models based on quantitative analysis from the perspectives of environmental benefits and social benefits.Firstly,the characteristics of UGS landscape patter and type in the study area were extracted based on the high-resolution remote sensing data.Taking the urban thermal environment and residents’ travel preference as representatives,this study discussed the impact of UGS characteristics on its environmental and social benefits,according to which evaluation models were constructed and applied in the study area.The main research contents and conclusions are as follows:(1)In terms of UGS classification,this study explored a classification method based on feature optimization using GF-6 remote sensing data.The spectral,texture and geometric features of image objects were extracted,and the random forest algorithm was used for feature optimization and classification,obtaining a classification accuracy of 91.7%.The classification of UGS is conducive to the detailed analysis of landscape pattern characteristics,and provides input for the quantitative analysis of environmental and social benefits.(2)In terms of environmental benefit analysis,combined with thermal infrared remote sensing data,this study quantitatively analyzed the relationship between UGS landscape pattern and land surface temperature(LST)using geographical detector,so as to explore the influence of different landscape patterns on UGS thermal environmental benefit.The results show that: 1)spatial allocation and configuration of UGS impact LST at both landscape and class levels,and the impact varies significantly with different vegetation types and landscape patterns.2)The influence of each pair of driving factors on UGS thermal environmental benefits is mutually enhanced,indicating that urban greening can be improved across multiple dimensions.(3)In terms of social benefit analysis,combined with population heat map,this study discussed the impact of the quantity,quality and accessibility of UGS on residents’ travel preference.The results show that: 1)the influence of characteristics of UGS on population heat difference is accessibility > quantity > quality.2)The impact of the number of bus stations is equivalent to the road density,follewed by the number of subway stations.3)The influence of aggregation index of UGS is slightly greater than diversity.(4)In terms of UGS evaluation,according to the quantitative analysis results of environmental and social benefits,the green environmental benefit index and green social benefit index were constructed respectively.To improve the continuity and fineness of the evaluation results,the moving window method was used to calculate the evaluation indexes,and the evaluation results were analyzed and discussed from three levels: overall characteristics,sample cases and cold/hot spots.(5)This study proposed a construction method of UGS evaluation model based on quantitative analysis of the real situation of the city,providing a more scientific framework for UGS evaluation.At the same time,typical cases are provided in terms of environmental benefits and social benefits respectively.The results showed the effectiveness of geographical detector in revealing the complex relationship between UGS characteristics and urban thermal environment or residents’ travel preferences.The evaluation model based on the quantitative analysis results is scientific and reliable,and can objectively reflect the quality of urban green space.