关中平原城市群景观格局指数对PM_(2.5)模拟的影响

Effect of landscape pattern index on PM_(2.5) simulation in Guanzhong Plain Urban Agglomeration

可入肺颗粒物(PM_(2.5))与城市空气质量和人类健康密切相关,而土地利用景观格局是影响PM_(2.5)的关键因素之一,探究土地利用景观格局与PM_(2.5)之间的影响机制对环境保护和治理意义重大。基于PM_(2.5)监测站点数据和辅助数据,利用地理加权回归模型模拟分析关中平原城市群2015—2019年PM_(2.5)浓度,使用主成分分析筛选出表征城市群土地景观破碎度的景观蔓延度指数,将其引入地理加权回归模型分析景观格局指数对PM_(2.5)浓度模拟的影响,分别采用空气质量监测站点实测数据和第三方空气污染数据集(CHAP)进行模型精度验证。结果显示:加入景观蔓延度指数后,地理加权回归模型拟合实测数据能力更强,验证精度和稳定性较好,拟合优度综合提升4.65%;这表明引入景观指数所构建的地理加权回归模型能够以较高的空间分辨率和精度模拟关中平原城市群PM_(2.5)浓度。研究结果不仅有助于了解关中平原城市群PM_(2.5)的影响因素及其空间异质性,而且有助于更好地认识景观格局对PM_(2.5)的综合影响,为城市群在景观尺度的大气污染防控提供科学支撑。

PM_(2.5) is related to urban air quality,while human health and landscape pattern of land use is one of the key factors affecting PM_(2.5).As a spatial carrier of PM_(2.5),landscape pattern is inevitably affecting local and regional PM_(2.5) concentration.It is of great significance to explore the influence mechanism between landscape pattern and PM_(2.5) for environmental protection and air pollution control.Based on PM_(2.5) monitoring station data and auxiliary data,the geo-weighted regression model(GWR)was used to simulate conditions on the PM_(2.5) concentration in the Guanzhong Plain Urban Agglomeration from 2015 to 2019.Then the landscape sprawl index(CONTAG)was selected by the principal component analysis,and introduced into the GWR model to analyze the influence of landscape pattern index on the PM_(2.5) concentration simulation.The accuracy of the PM_(2.5) concentration modelling was validated with the observed data from air quality monitoring stations and third-party air pollution dataset(CHAP)respectively.The results show that CONTAG added makes the GWR model more suitable for the characteristics of the field-observed data itself with better validation accuracy and stability,and improves the goodness of fit by 4.65%.It was indicated that the GWR model with landscape index incorporated can simulate PM_(2.5) concentration in Guanzhong Plain Urban Agglomeration with high spatial resolution and accuracy.The results not only conduce to understand the influencing factors and spatial heterogeneity of PM_(2.5) especially the comprehensive impact of landscape pattern on PM_(2.5) in Guanzhong Plain Urban Agglomerations,but also sever the purpose of providing scientific support for air pollution prevention at the landscape scale in urban agglomerations.