摘要
空气中的细颗粒物(PM_(2.5))是我国城市空气污染的主要污染物之一,严重威胁着城市居民的健康,限制城市发展的可持续性。PM_(2.5)去除的自然途径有两种,分别是干沉降和湿沉降,其中干沉降占据主导作用,且干沉降的过程和效率与城市森林紧密关联。目前针对城市森林对干沉降作用的研究主要是在小尺度中从不同树种、不同群落结构、不同景观类型等角度来估算并比较其滞尘量,较少关注其占空气污染总量的比率,从而可能影响对城市森林滞尘服务能力的判断。因此,利用城市森林效益(Urban Forest Effect,UFORE)模型中的大气污染干沉降模块的核心算法,以2015年为例,估算了我国主要城市辖区的城市森林一年内对大气中的PM_(2.5)削减量以及其占空气中PM_(2.5)污染总量的比重。结果显示:(1)2015年全国主要城市单位绿地面积日均滞尘量较高地区主要集中在华北地区、华东地区、以及东北地区。其中北京30.47mg/m^(2),苏州24.63mg/m^(2),沈阳28.55mg/m^(2)。(2)城市森林的滞尘效果具有明显的季节效应,冬季滞尘量明显高于夏季,而夏季滞尘率高于冬季。(3)虽然滞尘总量较大,但城市森林对城市空气污染物的滞尘量占空气PM_(2.5)污染总量的最大值不到4%,凸显出客观认识城市森林滞尘作用的必要性。本文的研究结果可为城市大气污染的生态解决方案和生态宜居城市建设提供一定的科学支撑。
Fine particulate matter(PM_(2.5))is one of the major contaminants of the urban air pollution in China,which seriously threatens the health of urban residents and affects the sustainability of urban development.There are two natural ways to remove it,namely dry deposition and wet deposition,in which dry deposition plays a leading role,and the process of dry deposition is inseparable from urban forest.At present,the research on the reduction effect of urban forest on air pollutants is mainly to estimate and compare its dust retention from the perspective of different tree species,different community structures and different landscape types on a small scale,and pays less attention to its ratio to the total air pollution,which may affect the judgment of urban forest dust retention service capacity.Therefore,using the core algorithm of air pollution dry deposition module in UFORE(urban forest effect)model and taking 2015 as an example,this paper estimated the reduction of PM_(2.5)in the atmosphere and its ratio to the total amount of pollutants in the air,i.e.dust retention rate in China.The results show that:(1)in 2015,the areas with high daily dust retention per unit green area in major cities in China were mainly concentrated in North China,East China and Northeast China,such as 30.47mg/m^(2)in Beijing,24.63mg/m^(2)in Suzhou,and 28.55mg/m^(2)in Shenyang.(2)The dust retention effect of urban forest has obviously seasonal effect.The dust retention amount in winter is significantly higher than that in summer,and the dust retention rate in summer is higher than that in winter.(3)Although the total amount of dust retention is large,the dust retention of urban forest to urban air pollutants accounts for less than 4%of the total amount of air pollution,highlighting the necessity of objectively understanding the dust retention function of urban green space.The research results of this paper can provide some scientific supports for urban air pollution prevention and ecological livable city construction.
作者
李家馨
韩立建
张志明
周伟奇
李伟峰
钱雨果
LI Jiaxin;HAN Lijian;ZHANG Zhiming;ZHOU Weiqi;LI Weifeng;QIAN Yuguo(School of Ecology and Environmental Science,Yunnan university,Kunming 650031,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《生态学报》
CAS
CSCD
北大核心
2023年第7期2640-2649,共10页
Acta Ecologica Sinica
基金
国家自然科学基金项目(32071579)。
