城市公园秋冬季典型天气和不同绿地对PM2.5浓度的影响

Effect of Weather and Green Space on PM2.5 Concentrations in Urban Park in Autumn and Winter

以杭州市临安区狮山公园中草坪、乔草和乔灌草3种不同植物配植类型样地为研究对象,在2019年秋、冬两季选择“连续晴天”“连续阴天”和“雨后晴天”3种典型天气,对公园内不同植物配植类型绿地的PM2.5浓度及气象因子(温度、相对湿度和风速)进行监测,探究天气条件和绿地对城市公园环境中PM2.5浓度的影响。结果表明,PM2.5浓度有明显的季节差异,冬季的PM2.5浓度高于秋季的;天气条件对PM2.5浓度变化作用明显,“连续阴天”的PM2.5日平均浓度显著高于其他2种天气的;在3种天气条件下,PM2.5浓度与温度之间呈极显著负相关、与相对湿度之间呈极显著正相关、与风速之间呈极显著负相关(除“连续阴天”以外),相对湿度是影响PM2.5浓度最主要的气象因子;公园内3种不同植物配植类型绿地的PM2.5浓度表现为草坪>乔草>乔灌草。

Determinations were implemented during September 2019 and January 2020 on PM2.5 concentration,air temperature,relative humidity and wind speed in different plant distribution sample plots under different weather conditions in Shishan Park of Lin’an,Zhejiang province.The results showed that the PM2.5 concentrations in winter were higher than that in autumn.The daily average PM2.5 concentration in continuous cloudy days was remarkably higher than that of the left.Under different weather conditions,there was extremely significant negative correlation between PM2.5 concentration with temperature and wind speed(except in continuous cloudy days),but significant positive one with relative humidity.The relative humidity was the main factor to influence PM2.5 concentration.The experiment demonstrated that concentration of PM2.5 in different green spaces was ordered by lawn>trees and grasses>trees,shrubs and lawn.