Diurnal variations in the mass concentration of suspended Particulate Matter 2.5 (PM2.5) of different urban green space
Guo Hanwen, Ding Guodong, Zhao Yuanyuan, Gao Guanglei, Chen Mingxiu, Wang Haiyong, Lai Wenhao
(Key Lab. of Soil & Water Conservation and Combating Desertification, Ministry of Education, College of Soil and Water Conservation, Beijing Forestry University, 100083, Beijing, China)
Abstract:Taking the Beijing Forestry University campus (BFU) (the green coverage is 42.2%), Olympics Forest Park (OFP) (the green coverage is 70.3%) and Jiufeng National Forest Park (JNFP) (the green coverage is 96.2%) as the study area, and their surrounding main roads as the contrast, the diurnal variation characteristics of Particulate Matter 2.5 (PM2.5) of different urban green spaces were analyzed by observation means. The results indicated that: 1) The PM2.5 mass concentrations decreased progressively with the increase of green coverage rate. The highest values of PM2.5 mass concentrations in BFU, OFP and JNFP were 140, 62 and 48μg/m3 respectively, which were strongly higher than the national annual average standard of China (35μg/m3). 2) There was no significant difference in the PM2.5 mass concentration between urban green space and the corresponding surrounding roads. 3) Weather conditions strongly influenced the PM2.5 mass concentrations. The mass concentrations were much higher in cloudy days (80-110μg/m3), but significantly decreased by approximately 80% after precipitation.