Building An Urban Green Space Regulation Index System Based On 3D Green Volume

With the continuous improvement of urban construction and industrialization,the frequent occurrence of urban ecological environment problems,the importance and urgency of protecting the urban green environment have gradually been widely recognized and accepted.Consensus on the quality of urban green space construction.The scientific evaluation of the level of urban green space construction helps to more accurately measure and evaluate the quality of urban green space and the benefits of ecological services,and facilitates the dynamic monitoring and scientific management of the entire process of urban green space planning and design after implementation.Compared with the single vegetation space types such as forest,grassland and farmland,the urban green space environment has obvious multidimensional spatial structure and diversity of vegetation types.However,in the current related research,the spatial pattern analysis and construction level evaluation of urban green space are still mainly limited to two-dimensional space,and it is difficult to truly reflect the spatial characteristics of urban green space,a three-dimensional green space.Therefore,it is necessary to start with three-dimensional space.Three-dimensional green quantity and three-dimensional indicators are introduced to realize the comprehensive consideration of urban green space environment construction quality,spatial characteristics and ecological benefits.At present,there is no research related to three-dimensional green quantity evaluation indicators at home and abroad,and there is a lack of standards or norms to measure the level of urban garden construction and greening benefits from threedimensional space nationwide.This study intends to propose a method to quickly realize the quantification of three-dimensional green volume in large-scale sites by sorting out the research status and application status of three-dimensional green volume at home and abroad.And take this as the core to build a three-dimensional control index system for urban green space based on three-dimensional green volume.Taking 413 domestic cities as the research object,on the basis of independently establishing the scope of urban built-up areas,from the perspective of two-dimensional and three-dimensional space,with the help of GIS technology,combined with the 2020NPP/VIIRS global night light data,impermeable surface data and global canopy height data,carry out the calculation of urban green space area and urban three-dimensional green volume,and put forward corresponding measures for the main statistical indicators of urban green space,including urban green space rate,green coverage rate of built-up areas,and per capita park area.Three-dimensional statistical indicators and related analysis,including three-dimensional green volume per capita,threedimensional green volume per unit area,three-dimensional green volume per unit green area,and three-dimensional green volume per unit area in urban and rural areas,so as to explore the relationship between urban green space volume distribution and urban green space distribution Through visual analysis,establish a three-dimensional evaluation index system for urban green space that can scientifically evaluate the level of urban greening construction,guide the healthy development of urban green space,and provide reference for urban green space planning and design and beautiful city construction.In this study,through the analysis and thinking of the results of the twodimensional green space index and the three-dimensional green volume index of 413 cities across the country,the factors that affect the three-dimensional green volume of the city are summarized,and the strategy of optimizing the urban green space is proposed,aiming at The spatial planning of urban green space to maximize the ecological benefits of urban green space provides a scientific basis.The results show that:(1)There are large differences in the index data among different cities.Under the large-scale research area,the vegetation volume is selected as the threedimensional green volume index of urban built-up areas,and the total threedimensional green volume of 413 urban built-up areas in the country in 2020 is168,299,925,364 m3,and the average three-dimensional green volume of each urban built-up area is 407,505,872.6 m3,the city with the lowest three-dimensional green volume is Rushan City,Shandong,at 8,031,100 m3;the city with the highest threedimensional green volume is Shanghai,at 7,116,784,500 m3,and the data varies greatly among different cities.The total three-dimensional green volume per capita is189,216.77m3,and the average per capita three-dimensional green volume is 458.15m3;the total three-dimensional green volume per unit area is 1154.95m3/m2,with an average of 2.80m3/㎡;the total three-dimensional green volume per unit green area is3935.02 m3 /m2,with an average of 9.53m3/m2;the total three-dimensional green volume per unit area in urban and rural areas is 5322.50m3/m2,with an average of12.89m3/m2.(2)The spatial distribution characteristics of urban three-dimensional green quantity are obvious.According to the division of geographical regions in my country,cities with high three-dimensional green quantity and high three-dimensional index values are concentrated in the eastern and southwestern regions,and there are also a small number of cities in some parts of Guangdong Province and the northeastern region.Cities with low three-dimensional green quantity and three-dimensional index values are concentrated in the central region.In other words,the three-dimensional green quantity and various three-dimensional indicators of cities in Northwest China,North China and Central China are generally low,while those in East China,Southwest China and South China are relatively high.(3)The correlation between the three-dimensional index and the two-dimensional index is low.Although the spatial distribution of the three data sets of green area and threedimensional green volume,per capita green area and per capita three-dimensional green volume,and green area rate and unit area three-dimensional green volume are roughly similar,the correlation presented by linear analysis is relatively low.,and the correlation of the three sets of data decreases successively,that is,there are more cities with high two-dimensional indicators but relatively low three-dimensional indicators.For example,in Shenmu City,Haiyang City,Shuozhou City,Linqing City,Weihai City,Rongcheng City and other regions,the green area is high and the three-dimensional green volume is relatively low.Another example is Luzhou City and Yingkou City.The green area rate of Luzhou City is 36.01%,and that of Yingkou City is 35.99%.m3/m2).It can be seen that the existence of three-dimensional green quantity and threedimensional indicators can avoid the irrationality in the evaluation of urban green space that the ecological benefits are greatly different due to the same green area rate or green area.Consideration of differences in ecological benefits and functional levels.Therefore,when evaluating the level of urban green space construction,it is necessary to introduce three-dimensional indicators with three-dimensional green quantity as the core,because there are certain limitations in relying only on two-dimensional indicators.