RCEES OpenIR  > 城市与区域生态国家重点实验室
北京市城郊空气质量差异研究
Alternative TitleStudy on urban-exurban differences of ambient air quality in Beijing
王姣
Subtype硕士
Thesis Advisor王效科
2011-05-25
Degree Grantor中国科学院研究生院
Place of Conferral北京
Degree Discipline生态学
Keyword空气污染 Air Pollution 城郊差异 Urban-exurban Differences 影响因素 Influencuing Factors 北京 Beijing
Abstract空气环境质量直接关系到一个城市的综合竞争力,直接影响到城市投资环境和居民健康以及城市可持续发展。北京作为我国的首都城市和社会经济政治中心,城市快速发展造成能源资源消费的剧增,机动车保有量的增加,建筑工地的遍布,将直接影响城市空气环境质量。本研究选取了北京市城区、近郊区和远郊区这三种典型区域为研究对象,于2008年至2010年期间进行了SO2、CO、NOx、O3和PM2.5的同步对比观测,研究城郊空气质量差异及影响因素,将为制定大气污染物控制措施提供科学依据。得到如下主要结论:
1)城区和近郊区空气质量对比:SO2、CO、NOx浓度的月变化和季节变化趋势相似,一般在1月、12月的浓度较高,在5月至8月的浓度较低,呈现冬季>秋季>春季>夏季的变化规律。近郊区的SO2、NOx浓度一般高于城区,与近郊区居民长期以煤作为日常生活和取暖的能源有关。两站点的CO浓度差异则不太明显,可能与CO的来源比较复杂有关。O3浓度也呈现出明显的月变化及季节变化规律。6月、7月、8月的O3浓度是1月、12月的1.9-5.5倍,O3浓度夏季最高,春季、秋季其次,冬季最低。城区和近郊区的O3浓度一般差别不大。2008年1月至2009年3月,近郊区的PM2.5平均浓度为59.1μg/m3,比城区低36%。2009年4月起,近郊区的PM2.5浓度开始超过城区,PM2.5的平均浓度为95.5μg/m3,比城区高60%。这种站点间PM2.5浓度的差别与站点周边建筑活动关系密切。总体上看,SO2、CO、NOx、O3在城区和近郊区的差异不显著(P>0.05),但PM2.5在两站点间的差异显著(P=0.027)。
2)城区、近郊区和远郊区空气质量对比:城区、近郊区大气中的SO2、CO、NOx浓度全年四季都呈双峰型日变化,而远郊区没有明显的日变化,主要与城区、近郊区人类活动的日变化有关。SO2、CO、NOx浓度在冬季明显高于夏季,主要是受北京冬季取暖以及低边界层等的影响。三个站点大气中的O3浓度在四季都呈单峰型日变化,表明局地光化学O3生成起主导作用。城区和近郊区的O3浓度夜间降至接近零,主要因为城区和近郊区夜间存在大量NO排放源,NO对O3的滴定作用导致O3浓度的极大降低。O3污染主要出现在春季和夏季,冬季O3污染较轻。城区PM2.5浓度的日变化呈双峰态势,在上午7:00-10:00和夜间0:00左右出现高峰。近郊区和远郊区PM2.5浓度一天内出现多个峰值,但7:00至11:00以及16:00至次日0:00浓度较高。远郊区PM2.5污染严重与其观测点周边的开山活动有关。从整体趋势上看,城区和近郊区大气中的SO2、CO、NOx 浓度明显高于远郊区,远郊区的O3浓度明显高于城区和近郊区,近郊区的PM2.5污染最重,远郊区次之,城区最轻。
3)空气污染物与气象因素的相关关系:SO2、CO、NO、NO2与温度、风速、太阳辐射负相关,与相对湿度、气压正相关。O3与气象因素的相关关系则与上述初级污染物相反。进一步研究表明,太阳辐射是影响白天O3浓度变化的最主要的气象因素。PM2.5与温度、风速、太阳辐射、气压的相关关系不显著。PM2.5与相对湿度显著正相关。
4)2010年5月至9月城区和近郊区PM2.5元素组成(Al、As、Ca、Cd、Co、Cr、Cu、Fe、K、Mg、Mn、Na、Ni、Pb、Se、V、Zn等)对比:地壳元素Al、Ca、Fe、K、Mg、Na浓度在两站点间的差异最大。近郊区其余污染元素(As、Cd、Co、Cr、Cu、Mn、Ni、Pb、Se、V、Zn)的富集因子一般也高于城区,尤其是Pb、As元素,这可能与被污染土壤和建筑物等的二次污染有关。来自地表和建筑工地的扬尘是造成两站点大气PM2.5中污染元素差异的主要原因。
5)北京市空气质量是自然因素和人为因素共同作用的结果,但当前北京市空气污染物的主要来源是人类活动,如燃煤、机动车尾气、建筑施工等。因此加强人类活动的管理和控制是治理北京市城区空气污染、提高空气环境质量的重要途径。
Other AbstractAir environment quality is closely related to urban comprehensive competitive power. It affects urban investment environment, residents’ health and sustainable urban development directly. As the capital city and economic and political centre of China, Beijing’s rapid development has caused soaring energy and resource demand, increasing motor vehicle quantities and spreading of constructions sites, which can affect urban air quality directly. In this study, the concentrations of air pollutants SO2, CO, NOx, O3 and PM2.5 in three representative regions of Beijing i.e. central urban, urban-fringe and exurban were analyzed based on the data from 2008 to 2010. Study on urban-exurban differences of air environment quality and its influencing factors is an important topic. It can provide scientific basis for the formulation of air pollution control measurements. Main results and conclusions are as follows:
1) Comparisons of air environment quality between central urban and urban-fringe regions: the monthly variation trends of SO2, CO and NOx were similar, so were the seasonal variation trends. Generally, the average concentrations in January and December were higher than those in other months, while the average concentrations from May to August were lower than those in other months. The seasonal variations of SO2, CO and NOx concentrations showed such patterns: winter > autumn > spring > summer. The SO2 and NOx concentrations in central urban region were generally lower than those in urban-fringe region due to the residents’ domestic use of coal burning in urban-fringe region. The differences of CO concentrations between the two regions were not obvious, which might be due to complicated CO sources. The O3 concentration also showed distinct changes over months and seasons. The average O3 concentrations from Jun to August were 1.9-5.5 times the concentrations in January and December. The O3 concentration was highest in summer, and lowest in winter. The O3 concentrations between the two regions had little differences.From January 2008 to March 2009, the average mass concentration of PM2.5 in urban-fringe region was 59.1μg/m3, which was 36% lower than that in central urban region. However, from March 2009 to December 2010, the average mass concentration of PM2.5 in urban-fringe region was 95.5μg/m3, which was 60% higher than that in central urban region. The differences of PM2.5 mass concentrations between the two regions were closely related to construction activities nearby. Overall, the differences of SO2, CO, NOx and O3 concentrations between central urban and urban-fringe regions were not significant (P>0.05). However, the difference of PM2.5 concentrations between the two regions was significant (P=0.027).
2) Comparisons of air pollutants in central urban, urban-fringe and exurban regions: the diurnal changes of SO2, CO and NOx concentration showed two peaks’ types in four seasons in central urban and urban-fringe regions, which were consistent with the characteristics of anthropogenic activities. However, no obvious diurnal variations in SO2, CO and NOx concentration were found in exurban region. The concentrations of SO2, CO, NOx were significantly higher in winter than those in summer, indicating the impact of winter heating in Beijing and low atmospheric boundary layer. Moreover, the diurnal change in O3 concentration showed one peak pattern at four seasons, suggesting the leading role of local photochemical formation. The O3 concentration in central urban and urban-fringe regions dropped to nearly zero at night. In central urban and urban-fringe regions, a large number of NO emission sources at night may play an important role in titration of O3, which can lead to great reduction of O3 concentration. Furthermore, the O3 pollution was serious in spring and summer, but light in winter. The diurnal variation of PM2.5 in central urban showed two peaks’ patterns with one peak from 7:00 to 10:00 in the morning, another around 0:00 at night. The PM2.5 concentrations in urban-fringe and exurban regions both had several peaks within a day. In these two regions, the PM2.5 concentrations from 7:00 to 11:00 and from 16:00 to next 0:00 were higher than those in other hours. The serious PM2.5 pollution in exurban might be related with mining activities nearby. Overall, the concentrations of SO2, CO, NOx in central urban and urban-fringe regions were higher than those in exurban region, whereas the O3 concentration showed an opposite distribution. The PM2.5 pollution in urban-fringe ergion was the most serious, followed by exurban. The PM2.5 pollution in central urban region was the lightest.
3) The correlations between air pollutants and meteorological factors: SO2, CO, NO and NO2 were negatively correlated with temperature, wind speed and solar radiation, but positively correlated with relative humidity and air pressure. O3 had opposite coefficients with above meteorological factors as apposed to these primary pollutants. Further research showed that solar radiation was the most important meteorological factor impacting O3 concentrations in the daytime. The correlation coefficients between PM2.5 concentration and temperature, wind speed, solar radiation and air pressure were not significant. PM2.5 concentration had significantly positive correlations with relative humidity.
4)Comparisons of elemental compositions (i.e. Al, As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, V and Zn) in central urban and urban-fringe regions: the differences of crustal elements Al, Ca, Fe, K ,Mg, Na concentrations in PM2.5 samples between the two regions were largest. The enrichment factors of the other elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, V and Zn) in urban-fringe region were generally higher those in central urban region, especially for Pb and As, which might be related to secondary pollution of contaminated soil and buildings near urban-fringe region. Dust from the surface and construction sites may be the main reason for the serious PM2.5 pollution in the two regions.
5)The urban-exurban differences of air environment quality in Beijing are effected by joint action of natural and anthropogenic factors. However, the main sources of air pollution in Beijing are human activities, such as coal burning, motor vehicle exhaust, construction. Thus, strengthening the management and restriction of human activities is an important way to control urban air pollution and improve the quality of air environment in Beijing.
Subject Area城市生态学
Language中文
Document Type学位论文
Identifierhttp://ir.rcees.ac.cn/handle/311016/728
Collection城市与区域生态国家重点实验室
Recommended Citation
GB/T 7714
王姣. 北京市城郊空气质量差异研究[D]. 北京. 中国科学院研究生院,2011.
Files in This Item:
File Name/Size DocType Version Access License
北京市城郊空气质量差异研究-王姣.pdf(1638KB) 开放获取LicenseApplication Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[王姣]'s Articles
Baidu academic
Similar articles in Baidu academic
[王姣]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[王姣]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.