道路绿地对PM2.5等颗粒物的作用效果及影响机制  

Effects of road green space on concentrations of particulate matters such as PM2.5 and its mechanism

作　　者：丁文[1] 贾忠奎[1] 席本野[1] 施侃侃[1] 施晓灯 DING Wen;JIA Zhongkui;XI Benye;SHI Kankan;SHI Xiaodeng(Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学省部共建森林培育学科与保护重点实验室,北京100083

出　　处：《福建农林大学学报（自然科学版）》2018年第6期729-735,共7页Journal of Fujian Agriculture and Forestry University:Natural Science Edition

基　　金：北京市海淀区支农专项基金资助项目

摘　　要：选取北京市北四环西路两处不同结构的道路绿地(密集型、疏透型),根据绿地与道路的垂直距离(绿地深度),分别在0～60 m选定5个观测点,对PM1、PM2.5、PM10等不同粒径颗粒物浓度进行实时监测,并同步测定风速、风向、温度与相对湿度等.结果表明:(1)不同空气污染级别下,绿地内PM2.5等颗粒物浓度没有表现出统一的日变化规律.不同粒径颗粒物之间呈高度正相关(P<0.01),粒径差异越小,相关系数越大;但严重大气污染下PM1与PM2.5等其它粒径颗粒物表现出相反的变化趋势.(2)绿地内颗粒物浓度与相对湿度表现出较强的正相关性(P<0.01),相关系数表现为PM1>PM2.5>PM4>PM10>TSP;颗粒物浓度与温度呈负相关(P<0.05),相关性表现为PM2.5<PM4<PM10<TSP,而PM1与温度不相关;颗粒物浓度与风向风速不相关.(3)不同结构绿地和绿地深度对风速影响显著(P<0.01),对相对湿度、温度、风向影响不显著;绿地对气象因子的影响主要表现为对气流的阻挡作用.(4)不同结构绿地之间颗粒物浓度差异不显著,不同绿地深度之间颗粒物浓度差异不显著;只有在空气质量状况为优时(PM2.5<35μg·m^(-3)),绿地颗粒物浓度(PM1除外)低于对照空地(比例为4.5%～23.0%),并且疏透型绿地净化效果优于密集型绿地(净化率高出6.0%);颗粒物粒径越大,对绿地的作用效果越显著.In order to figure out whether green space along city roads positively reduces particulate matters （PMs） such as PM2.5,and the method to make the most of it, 2 green spaces with distinct canopy density on the Forth Ring Road in Beijing were monitoredon PMs concentrations including PM1, PM2.5, PM10, etc. Five monitoring spots were set up based on distances between greenspace and the road within 60 m. And meteorological factors such as wind, humidity and temperature were also recorded. No patternwas found on daily PM variations under different polluted conditions. PMs in different sizes showed highly positive correlation （P〈0.01）,smaller the differences between particle sizes, higher the correlation coefficients became. But correlations reduced under ex-tremely polluted situation. PMs were positively related with relative humidity （P〈0.01）, with correlation coefficient in a descendingorder being PM1, PM2.5, PM4, PM10, TSP. While PMs showed negative relation with temperature except PM1, with correlationcoefficients in an ascending order being PM2.5, PM4, PM10, TSP. No correlation was found on wind speed and wind direction withPMs. Structure and depth of green spaces affected wind speed （P〈0.01）, but no obvious effect was observed on humidity, tempera-ture, and wind direction. Blocking air circulation was the main reason for green space＇s effect on meteorological factors. No signifi-cant differences was found on PMs concentrations from dense and sparse green spaces （P〉0.05）, neither green spaces with differentdepths. Only under good weather condition （PM2.5〈35 μg,m-3）, PMs concentrations except PM1 in green spaces were 4.5%-23.0% lower than those in the open area. Sparse green space was averagely 6.0% better than the dense one on purificating air. Andgreen space was more efficient in purificating PM with bigger size.

关 键 词：PM2.5 大气颗粒物 道路绿地 气象因子 

分 类 号：S731.2[农业科学—林学]