封城前后绿地景观格局对气溶胶影响的比较

Comparison of Effects of Landscape Patterns of Green Space on Aerosol before and after City Closure

交通和工业排放是大气污染的主要来源。先前研究并未充分理解剔除交通和工业排放前后绿地景观格局对气溶胶光学厚度(AOD)的影响,比较分析了疫情封城前后社会经济、路网密度、绿地景观指数与AOD之间的因果关系,采用随机森林量化不同绿地景观百分比下影响AOD的主导因子,探测绿地景观指数和AOD的空间自相关特征,然后采用多尺度地理加权回归来量化绿地景观指数对AOD的影响。结果表明,在不同绿地景观百分比和疫情封城前后影响AOD的主导因子具有差异。与疫情封城之前相比较,封城后绿地景观指数削减气溶胶污染的能力被减弱了,但影响因子对AOD的相对重要性得到了增强。绿地景观指数和AOD均存在显著的空间集聚特征。绿地景观指数在疫情封城前后对AOD的影响大小和尺度存在差异。研究结果有助于基于缓解AOD下绿地景观格局优化和政策制定。

Traffic and industrial emissions are major sources of air pollution.As previous studies have not fully understood the effect of landscape patterns in green space on aerosol optical thickness(AOD)before and after removing traffic and industrial emissions,this study comparatively analyzed the causal relationships between socio-economy,road network density,landscape metrics in green space and AOD before and after the epidemic closure,used random forest to quantify the dominant factors affecting AOD under different percentage of green space landscape,explored the spatial autocorrelation characteristics of landscape metrics in green space and AOD,and then used multi-scale geographically weighted regression to quantify the effect of landscape metrics in green space on AOD.The results showed that the dominant factors affecting AOD were different under different green space landscape percentages and before and after the epidemic closure.Compared with the period before the epidemic closure,the ability of the landscape metrics in green space to reduce aerosol pollution was diminished after the closure,but the relative importance of the influencing factors on AOD was enhanced.There were significant spatial clustering characteristics of both landscape metrics in green space and AOD.There were differences in the magnitude and scale of the influence of landscape metrics in green space on AOD before and after the epidemic closure.The results of the study contribute to the optimization of landscape pattern in green space and policy formulation based on AOD mitigation.