Study On The Correlation Between Urban Green Space Pattern And PM_2.5Concentration Based On MSPA

As China’s urbanization rate is increasing year by year,urban PM_2.5 pollution is particularly serious due to the city’s overloaded industrial production,high-density building environment,and excessive vehicle exhaust emissions.A large number of research results show that urban green space can play a very positive role in mitigating PM_2.5 pollution.In the case of limited urban green space,the current research is generally focused on optimizing the urban green space landscape pattern to improve PM_2.5 pollution.This article takes the main urban area of Wuhan as an example and innovatively uses Morphological Spatial Pattern Analysis（MSPA）analyzes the distribution and area of each element of the green spatial pattern,deeply studies the quantitative relationship between the urban green spatial pattern and PM_2.5 concentration,and implements it in specific spaces,and proposes to reduce PM_2.5 pollution in urban green space Structure and layout optimization strategy.This paper uses PM_2.5 concentration data with fixed monitoring points and rich data sources.And the PM_2.5 concentration distribution in the main urban area was obtained based on the Land Use Regression（LUR）model.Using the remote sensing image of high resolution No.2 in the main urban area of Wuhan with a spatial resolution of 0.8m,using object-oriented classification to interpret the high-definition remote sensing image to obtain green spatial distribution data,and analyzing the green spatial pattern based on MSPA,can make up for the limitations of previous research Due to the numerical analysis of the green space landscape pattern,it is impossible to carry out spatial distribution analysis.Finally,based on the PM_2.5 distribution data and green spatial pattern distribution data in the main urban area,correlation analysis and regression analysis are performed on the two.The main results obtained in this study are as follows.（1）The spatial distribution of PM_2.5 concentration in the main urban area of Wuhan was obtained based on the LUR model.According to PM_2.5 data at monitoring points and factors such as spatial form,terrain,traffic,climate,etc.,a LUR model is constructed to obtain the spatial distribution of PM_2.5 concentration in summer in the main urban area of Wuhan.After testing,the accuracy of the model prediction results is high.The higher PM_2.5concentration areas in the main urban area are more concentrated in the three sections of the south,middle and north of the main urban area.From the perspective of high PM_2.5concentration areas,higher concentrations of PM_2.5 are mainly concentrated in high-density regional spaces,large transportation hub stations,and industrial production plant areas in the city.（2）Based on MSPA,the green space pattern of Wuhan’s main urban area is analyzed.The analysis results show that the order of the proportion of the area of each element in the main urban area of Wuhan is in the order of core>islet>edge>bridge>branch>loop>perforation.Within the main urban area,the core is partially clustered and unevenly distributed.The islet is concentrated in the second ring line and around the second ring line.The bridge and loop have a large area in the southeast area of the main city,with edge and perforation.Outside the Second Ring Line,they are clustered in local blocks,and the branches are mostly distributed in the center of the main urban area and the area north of the center.（3）Correlation analysis and regression analysis between urban green space pattern and PM_2.5 concentration.The correlation between the area proportion of the seven types of landscape structural elements and PM_2.5 concentration is as follows:core>bridge>edge>perforation>islet>loop,the proportion of branch has no significant correlation with PM_2.5concentration Sex.Among them,when the core ratio is not more than 48%,the PM_2.5concentration has a negative correlation with the core;the PM_2.5 concentration and the bridge ratio always have a negative correlation;when the edge ratio is not more than 8%,PM_2.5.The concentration is negatively correlated with the edge;when the proportion of perforation is not greater than 4%,the PM_2.5 concentration is negatively correlated with the pores;the PM_2.5 concentration is always positively correlated with the proportion of islet;the proportion of loop has a negative correlation with PM_2.5.Taking PM_2.5 concentration as the dependent variable,the model relationship between core,bridge and PM2.5concentration is:Y=53.23-15.85Xcore-33.45Xbridge.（4）Urban green spatial pattern planning strategy to reduce PM_2.5 concentration.Macro-proposed four green space pattern optimization strategies for the main urban area of Wuhan City:increase and protect large green patches;construct green corridors to connect large green patches;break up patches in series through road green belts;connect and extend riverside green along the banks of the river band.Microscopically analyzing and optimizing the green spatial pattern of the texture unit in the main urban area,the results show that the MSPA-based urban green spatial pattern planning strategy has positive significance for mitigating PM_2.5 pollution in the main urban area.