The 3D Patten And Equitye Analysis Of Green Space In Wuhan Built-up Area

The accelerating urbanization process has changed the urban landscape and urban spatial structure,resulting in urban problems such as the decline of urban environmental quality and ecological concerns.Urban green space is an important component of urban space,and its role is not only as a green infrastructure of the city,but also as an important component of the urban ecosystem.The quality of urban green space is directly related to the sustainability of urban environment and the life of urban residents.Different types of urban green spaces have different vegetation distribution characteristics and spatial structures,but the criteria and indicators used in the current research on urban green spaces in China are usually based on two-dimensional indices of quantity and occupancy on the plane,which cannot truly reflect the vertical spatial structure of vegetation communities in urban green spaces.Some relevant studies have shown that there is a correlation between urban green space landscape pattern and the evolution of ecological processes.Combining the landscape pattern related indexes with urban green space evaluation indexes green space evaluation criteria can provide a more direct understanding of the evolution of urban green space spatial layout.The urban population density caused by urban development has increased dramatically,and the problem of fairness of urban green space allocation has become more and more prominent.This study proposes a new method for quantifying green space,starting from the three-dimensional space of green space,shifting from the previous green coverage to the occupancy of urban green space in the city,and combining with ecological landscape pattern analysis to more reasonably describe the distribution pattern and spatial heterogeneity of urban green space vegetation communities in three-dimensional space.The spatial distribution of the living vegetation volume in the city is combined with the spatial distribution of the city to explore its fairness.The range of built-up area of Wuhan city was taken as the research object,and the range of built-up area of Wuhan city was divided based on the definition of built-up area and the land cover type map of Wuhan city.Using the 10m high-resolution vegetation canopy height data,the living vegetation volume was measured in a spatial volume manner.The vegetation canopy height data were combined with the vegetation canopy height data to expand the landscape pattern index in three dimensions.A three-dimensional landscape pattern index system was constructed for the built-up area of Wuhan.The analysis of the living vegetation volume pattern of the built-up area is completed at four levels:living vegetation volume,patch,landscape and land type.Based on the living vegetation volume measurement,the fairness of the three-dimensional spatial resource allocation of green space in the built-up area is evaluated.Through the analysis,it is found that:(1)The living vegetation volume landscape pattern in the built-up area of WuhanThe total living vegetation volume in the built-up area is 7770362500 m~3,the per capita 3D green volume is 569.303 m~3,and the average unit green volume is 9.121 m~3/m~2.The total 3D green volume in the park green space is 746807000 m~3,and the per capita 3D green volume in the park green space is 54.71554484 m~3.The number of fishing nets,the number of patches and the volume of patches in Hongshan District are the largest among the jurisdictions,229,1793898 and 1696975523 m~3 respectively,and the smallest patch density is in Wuchang District,only 814986.276(m~3),the area with the highest maximum vegetation height is Hanyang District,with 41 m.The average vegetation height The highest average vegetation height was in Wuchang District with 11.017,and the highest plant Shannon diversity index was in Jiangan District with 0.635.The largest landscape percentage was in Hannan District with 95.52%,and the landscape segmentation in Hannan District with 0.821.The highest Shannon diversity index was in Hongshan District with a value of 0.762.The multi-index analysis concluded that at the patch level Wuchang District,Jiang’an District and Jianghan District,were more ecologically advantageous at the spatial The spatial level is more ecologically advantageous.and at the type level,Hongshan District,Jiang’an District and Jianghan District have more ecological advantages at the spatial level.At the landscape level,Hongshan District,Xinzhou District and Jangan District have more ecological advantages at the spatial level.(2)Fairness of green space based on living vegetation volumeThe Gini coefficient of living vegetation volume in the built-up area of Wuhan is 0.68,which indicates that the disparity in resource allocation within the area is very large.Within the built-up area,the largest Gini coefficient is 0.65 in Hongshan District,which has the lowest equity,and the smallest is 0.30 in Hannan District,which has the highest equity among the 13 jurisdictions and belongs to the more equitable range;among all jurisdictions,only two jurisdictions,Qingshan District and Hannan District,have a relatively equitable level of 3D green area distribution;the distribution of entropy levels in the built-up area of Wuhan City,in terms of area share,the area of high-ranking areas is more equitable.In terms of the distribution of area entropy levels in the built-up areas of Wuhan,the area share of high-grade areas is the largest,20.77%,and the area share of low-grade areas is the smallest,18.61%,while the population share of low-grade areas is the largest,49.66%,and the population share of high-grade areas is the smallest,only 2.35%.level.Finally,by summarizing and generalizing the names of the central sites within the ranked areas with different locational entropy values,it is concluded that the areas with low entropy values are mostly gathered in the residential areas in the center of the built-up areas,and the areas with high entropy values are mostly gathered in the areas such as urban parks and scenic recreational green areas with faster urban renewal development and better natural environment.