京津冀地区植被覆盖对大气颗粒物浓度的影响

Impact of Vegetation Cover on Atmospheric Particulate Matter Concentration in Beijing-Tianjin-Hebei Region

针对京津冀地区空气污染现象频发的问题,基于长时序NDVI、空气质量监测站等数据,从多种时间、空间尺度上分析植被覆盖对大气颗粒物浓度的影响。首先分析了NDVI的时空特征变化,然后探究了NDVI和颗粒物浓度的在时间和空间上相关性,最后比较了植被区和非植被区空气质量小时均值变化趋势。实验结果表明:NDVI月均值与颗粒物浓度变化趋势相关,研究区整体NDVI与PM2.5、PM10浓度月均值回归方程的R^(2)分别为0.580、0.601;植被覆盖对PM2.5和PM10浓度年均值的最佳影响尺度分别为3 km和2.5 km,各季节的最佳影响尺度中夏季最大、冬季最小;植被覆盖对颗粒物浓度升高有抑制作用,植被区颗粒物浓度的变化比非植被区更加平缓。

Aiming at the frequent air pollution in Beijing-Tianjin-Hebei region, based on the data of long-time NDVI and air quality monitoring stations, this paper analyzed the influence of vegetation cover on the concentration of atmospheric particulate matter from various time and space scales. Firstly, the temporal and spatial characteristics of NDVI were analyzed, and then the temporal and spatial correlation between NDVI and particulate matter concentration was explored. Finally, the hourly average change trend of air quality in vegetated and non-vegetated areas was compared. The results show that the monthly mean value of NDVI is related to the change trend of particulate matter concentration, and the R^(2) of the regression equation between the overall NDVI and the monthly mean values of PM2.5 and PM10 concentrations in the study area is 0.580 and 0.601,respectively. The best influence scales of vegetation cover on the annual mean values of PM2.5 and PM10 concentrations are 3 km and 2.5 km, respectively, and the best influence scales in each season are the largest in summer and the smallest in winter. Vegetation can inhibit the increase of particulate matter concentration, and the change of particulate matter concentration in vegetation area is gentler than that in non-vegetation area.