The accelerated growth of the vehicular fleet, the modernization of large urban centers, and the few adjustments to the road network in Fortaleza have intensified the problems of traffic and emissions of atmospheric p...The accelerated growth of the vehicular fleet, the modernization of large urban centers, and the few adjustments to the road network in Fortaleza have intensified the problems of traffic and emissions of atmospheric pollutants, highlighting the necessity for strategic urban planning initiatives to address the escalating issues of traffic and pollution. With the objective of analyzing the indices of concentrations of atmospheric pollutants and estimating how these levels can affect human health, this work consists of a study of the analysis of air quality in the intense trade region of Fortaleza. For this, the analysis zone was divided into three perimeters (Major - Medium - Minor), where each perimeter was analyzed at 7 am, 12 noon and 5 pm. Concentrations of the type of O<sub>3</sub>, particulate matter (PM<sub>2.5</sub> and PM<sub>10</sub>), CO<sub>2</sub> and HCHO were collected. Our results demonstrate that most of the analyses are within the limits of current legislation;however, at certain times and perimeters, the analyses of CO<sub>2</sub> and HCHO exceeded the established limits. In view of the above, we conclude that public policies to control air quality are necessary to reduce the damage to human health and the environment caused by pollutants.展开更多
The influence of reduction in emissions on the inherent temporal characteristics of PMand NOconcentration time series in six urban cities of India is assessed by computing the Hurst exponent using Detrended Fluctuatio...The influence of reduction in emissions on the inherent temporal characteristics of PMand NOconcentration time series in six urban cities of India is assessed by computing the Hurst exponent using Detrended Fluctuation Analysis(DFA) during the lockdown period(March 24–April 20, 2020) and the corresponding period during the previous two years(i.e., 2018 and 2019). The analysis suggests the anticipated impact of confinement on the PMand NOconcentration in urban cities, causing low concentrations. It is observed that the original PMand NOconcentration time series is persistent but filtering the time series by fitting the autoregressive process of order 1 on the actual time series and subtracting it changes the persistence property significantly. It indicates the presence of linear correlations in the PMand NOconcentrations. Hurst exponent of the PMand NOconcentration during the lockdown period and previous two years shows that the inherent temporal characteristics of the short-term air pollutant concentrations(APCs) time series do not change even after withholding the emissions. The meteorological variations also do not change over the three time periods. The finding helps in developing the prediction models for future policy decisions to improve urban air quality across cities.展开更多
This paper takes a comprehensive view at transportationrelated air pollution problems and solution options. While the transport infrastructure in major Chinese cities is briefed, the environmental impacts of transp...This paper takes a comprehensive view at transportationrelated air pollution problems and solution options. While the transport infrastructure in major Chinese cities is briefed, the environmental impacts of transport activities on urban air quality are discussed in detail. Not only the contribution of automotive emissions to the CO, NMHC and NO\-x pollution in urban areas is reviewed, but also concerns over the carcinogenic emissions, lead deposition and noise are presented. From a lifecycle view point, the impacts of motorway construction, as well as those from scrapped cars, car batteries and old tires in China have been taken into account. In the second part of this paper, the current technical efforts to curb vehicular emissions are evaluated. The performances of unleaded petrol, domestic catalytic converters, and fuel injection systems have been assessed. Options of cleaner alternative fuels and “green” vehicles are discussed, with both the life-cycle impacts and economic feasibility emphasized. Policy and management aspects for effective pollution control are tackled. In particular, speculations about potential economic incentives and legislative measures for vehicular pollution control are presented.展开更多
Urban areas around the world, particularly in emerging nations such as China, India, and Brazil are experiencing high levels of air pollution due to increased population, economy, spending, and consumption, all of whi...Urban areas around the world, particularly in emerging nations such as China, India, and Brazil are experiencing high levels of air pollution due to increased population, economy, spending, and consumption, all of which contribute to deterioration in environmental and public health conditions in urban areas. This paper briefly discusses important sources of air pollution, air pollutants of concern, public health impacts, and proposed strategies to combat urban air pollution and promote sustainable urban living. A team of researchers under the mentorship of the main author is working on a number of air quality projects that involve air quality monitoring (sources, ambient, indoor, and occupational), emissions modeling, atmospheric dispersion modeling, air pollution control, and development of knowledge-based systems to manage air quality.? This paper presents potential strategies that could help address the growing public health concerns in urban areas and promote sustainable and healthy living.展开更多
In this study, a new method for a comprehensive evaluation of air quality in urban agglomerations was developed based on a prototype used to solve the spatial Steiner-Weber point. With this method, the air quality inf...In this study, a new method for a comprehensive evaluation of air quality in urban agglomerations was developed based on a prototype used to solve the spatial Steiner-Weber point. With this method, the air quality information of each city in the city group is aggregated into an optimal gathering point, and then the air quality of the city group is then dynamically evaluated each year. According to the relevant data of the China Statistical Yearbook 2018, we applied this method to aggregate the air quality indices of the major cities in the Beijing-Tianjin-Hebei urban agglomeration from 2014 to 2017. Using the plant growth simulation algorithm (PGSA), the optimal assembly points were calculated to be of a higher accuracy, compared to the traditional mean value aggregation method. Finally, the air quality of the Beijing-Tianjin-Hebei urban agglomeration during each year was evaluated dynamically based on the obtained assembly points. The results show that the air quality of the urban agglomeration is ranked as follows: <span>Y2016<img src="Edit_28ddcae1-12ec-4d20-a4e9-77309c996766.bmp" alt="" /></span><span></span><span>Y2015<img src="Edit_5f164e96-55aa-4e37-98e1-6833665979d1.bmp" alt="" /></span><span></span><span>Y2017<img src="Edit_cfc0da49-7e3a-4aa8-82ac-ede99621d1ec.bmp" alt="" /></span><span></span><span>Y2014.</span>展开更多
Various postulations on the relationship between urban morphology and air quality are qualitative.This fails to establish the strength of the contributions of each morphological parameter in the spatial distribution o...Various postulations on the relationship between urban morphology and air quality are qualitative.This fails to establish the strength of the contributions of each morphological parameter in the spatial distribution of the air quality.It is this gap in knowledge that this study sought to fill by modelling the correlation existing between the urban morphological variables of development density,land uses,biomass index and air quality values of Nairobi city.While 30 development zones of the city constituted the target population,IKONOS satellite imagery of the city for the year 2015 was utilised in establishing the development densities,land uses and biomass index.The parameters were transformed into numerical surrogates ranging from 1 to 10 with lower values accorded to zones with low biomass index,the highest development density,noxious land uses,high gaseous concentrations and vice-versa.Pearson’s correlation coefficients(r),coefficients of determination(R),t-tests and the Analysis of Variance(F-tests)with levels of significance being 95%were used to determine the strengths,significances and consistencies of the established relationships.The study established that development density is the most significant morphological variable influencing the distribution of air quality.This is followed by biomass index and to a weaker extent,land uses.展开更多
A monitoring campaign of BTEX (benzene, toluene, ethylbenzene, o- m- and p-xylene) was carried out nearby two tunnel portals in the urban area of Naples with the aim to verify air quality in this kind of urban sites...A monitoring campaign of BTEX (benzene, toluene, ethylbenzene, o- m- and p-xylene) was carried out nearby two tunnel portals in the urban area of Naples with the aim to verify air quality in this kind of urban sites. Sampling was carried out using the active adsorption technique. Sampling time was 1 h. Ambient temperature and traffic flow measurements were carried out during each sampling operation. The results indicate that average benzene concentrations at both sites exceed the limit value of 10 μg/Nm^3 established by the European Community (EC) (Dir. 2000/69). Concentration levels of other BTEX are relatively high as well. A correlation between BTEX concentration and two wheeler vehicle flow was observed.展开更多
As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality e...As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality exceedances, common in large cities across Europe, particularly for NO2. Modeling air quality in urban areas is rather complex since observed concentration values are a consequence of the interaction of multiple sources and processes that involve a wide range of spatial and temporal scales. Besides a consistent and robust multi-scale modeling system, comprehensive and flexible emission inventories are needed. This paper discusses the application of the WRF-SMOKE-CMAQ system to the Madrid city (Spain) to assess the contribution of the main emitting sectors in the region. A detailed emission inventory was compiled for this purpose. This inventory relies on bottom-up methods for the most important sources. It is coupled with the regional traffic model and it makes use of an extensive database of industrial, commercial and residential combustion plants. Less relevant sources are downscaled from national or regional inventories. This paper reports the methodology and main results of the source apportionment study performed to understand the origin of pollution (main sectors and geographical areas) and define clear targets for the abatement strategy. Finally the structure of the air quality monitoring is analyzed and discussed to identify options to improve the monitoring strategy not only in the Madrid city but the whole metropolitan area.展开更多
ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we br...ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we briefly describe the ADMS dispersion models and give an overview of their use in China. And it describes in more detail the use of ADMS-Urban in Fushun in Liaoning province and in Jinan in Shangdong province respectively, for studies of urban air quality. Finally the conclusions are presented.展开更多
Based on measurements at the Beijing 325-m Meteorological Tower,this study reports an analysis of atmospheric stability conditions and turbulent exchange during consecutive episodes of particle air pollution in Beijin...Based on measurements at the Beijing 325-m Meteorological Tower,this study reports an analysis of atmospheric stability conditions and turbulent exchange during consecutive episodes of particle air pollution in Beijing(China),primarily due to haze and dust events(15–30 April 2012).Of particular interest were relevant vertical variations within the lower urban boundary layer(UBL).First,the haze and dust events were characterized by different atmospheric conditions,as quite low wind speed and high humidity are typically observed during haze events.In addition,for the description of stability conditions,the bulk Richardson number(RiB) was calculated for three different height intervals: 8–47,47–140,and 140–280 m.The values of RiB indicated an apparent increase in the occurrence frequency of stably-stratified air layers in the upper height interval—for the 140–280-m height interval,positive values of RiB occurred for about 85% of the time.The downward turbulent exchange of sensible heat was observed at 280 m for the full diurnal cycle,which,by contrast,was rarely seen at 140 m during daytime.These results reinforce the importance of implementing high-resolution UBL profile observations and addressing issues related to stably-stratified flows.展开更多
Freely available data of sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) observed in Arctic cities (north of 59.99 N) between 1972 and 2016 were compiled into an ai...Freely available data of sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) observed in Arctic cities (north of 59.99 N) between 1972 and 2016 were compiled into an air-quality inventory of samples taken for limited periods. For cities with multiple years of data, air-quality climatology was determined in terms of daily means in the annual course. Mean urban air-quality climatology was calculated for regions of similar insolation, emission standards, topography, Köppen-Geiger classification, and city size. Urban concentrations of PM precursors (SO2, NH3, NO2), PM2.5 and PM10 (PM with diameter less than 2.5 and 10 μm) were assessed in the sense of climatology with evidence from current knowledge. Typically, annual SO2 and NO2 means were lower for small than large Arctic cities, but can vary more than an order of magnitude over short distance. Cities seeing seasonal sea-ice had W-shaped mean annual courses of daily O3, while other cities had a spring maximum. Typically, annual means of urban pollutants in North America exceeded those in Scandinavia except for O3, where the opposite was true. Annual mean urban PM2.5 and PM10 concentrations varied from 1.6 to 21.2 μg·m-3 and 2 to 18.2 μg·m-3, respectively. Since PM10 encompasses PM2.5, annual PM10 means must be at least 21.2 μg·m-3. According to rural-to-urban ratios of species, seasonal transport of pollutants from wildfires, shipping, and the Kola Peninsula mining area occurred at some sites in Interior Alaska, western and northern Norway, respectively. Concurrent SO2 and PM or NO2 and PM measurements revealed combustion or traffic as major contributors to urban concentrations. Recommendations for potential future measurements of Arctic urban air quality were given based on the assessments of climatology and inventory.展开更多
[ Objective] The research aimed to study variation of the urban heat island (UHI) intensity and its relationships with air pollutants in Kunming. [ Method] Observation data of the air temperature series from Kunming...[ Objective] The research aimed to study variation of the urban heat island (UHI) intensity and its relationships with air pollutants in Kunming. [ Method] Observation data of the air temperature series from Kunming station and surrounding Taihuashan meteorological station were used to investigate the variation characteristics of UHI intensity in Kunming during 2001 -2010. Meanwhile, relationship between UHI intensity and air quality on the basis of concentration data for primary air pollutants (SO2, NO2 and PMlo ) from environmental monitoring station of Kunming was studied in this paper. [Result] Annual mean UHI intensity increased at the rate of 0.110 ℃/10 a, and UHI intensity was higher in dry season than that in rainy season. The change trend of air pollutants level in Kunming was in accordance with that of the UHI intensity. When UHI intensity reached peak value, air pollutants showed high concentration. UHI intensity had significantly positive correlation with air pollutants level. Annual mean UHI intensity had significantly positive correlation with PMlo level under the likelihood of 95%, but monthly mean UHI intensity had significantly positive correlation with NO2 level under the likelihood of 99%. In addition, annual statistics days with Grade I air quality obviously decreased with the strengthenment of UHI intensity. Therefore, air quality in Kunming City tumed more deteriorated with the enhancement of UHI intensity. [ Conclusion] The research findings provided a valid scientific basis for the mitigation of UHI and improvement of the atmospheric environment in Kunming.展开更多
Rwanda is a landlocked republic in Equatorial Africa. The capital Kigali (1°57'S, 30°04'E) can be mentioned as a typical African city due to its rising population and the rising rate of motorization....Rwanda is a landlocked republic in Equatorial Africa. The capital Kigali (1°57'S, 30°04'E) can be mentioned as a typical African city due to its rising population and the rising rate of motorization. Different pollutants produced e.g. by a highusage rate of mopeds or open fireplaces burning wood for cooking and household chores could be detected. Climatological parameters as well as air pollutants were measured within the urban area. Additionally, highly frequented spatial and temporal mobile measurements of particulate matter were taken during different dry seasons regarding different conditions. These values indicated an urban heat island, which tended to rise for the last four decades. A temporary phenomenon for the air pollution indicators is visible during clear and calm weather situations, e.g. the distinctive relief caused an accumulation within small valleys called “Marais” in the night time. Unfortunately, these are the favourite places for living and agriculture. So there is no infrequence in values of PM10 > 1.000 μg·m-3. The origin of the different airborne particles was verified by using a scanning electron microscope and it could be mentioned that most particles were from the combustion of biomass and traffic.展开更多
Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric pow...Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric power plants enter the lungs and pollute the blood of urban residents leading to a burden of disease with more than 3 million premature deaths per year attributed to outdoor air pollution. Welfare losses including premature deaths associated with air pollution were about $5 trillion in 2013. A global transition to electric vehicles, and the generation of electricity without combustion emissions would improve air quality significantly and reduce greenhouse gas emissions. This transition is in progress in many parts of the world with more than 2 million electric vehicles in service in 2017. Electric bus and electric taxi sales are increasing, and many large cities have multiple programs to improve air quality. When health costs are considered, it is very appropriate for communities to take action to improve air quality and health. This work reviews and reports many positive actions that are in progress in larger cities.展开更多
近年来城市形态对空气质量的影响研究引起了国内学者的广泛关注,获得了大量研究成果,但仍然缺乏系统梳理。作者以中国期刊全文数据库(CNKI)和美国科学情报研究所Web of Science核心合集为数据源,采用文献归纳法和CiteSpace软件,对2000至...近年来城市形态对空气质量的影响研究引起了国内学者的广泛关注,获得了大量研究成果,但仍然缺乏系统梳理。作者以中国期刊全文数据库(CNKI)和美国科学情报研究所Web of Science核心合集为数据源,采用文献归纳法和CiteSpace软件,对2000至2022年发表的我国城市形态对空气质量影响的文献进行了系统分析。研究发现:年度发文量整体呈上升趋势,2017年后英文文献发文量高于中文文献量,中英文研究机构重合度较低,缺少合作研究;研究主要以区域尺度和局地尺度为主,微观尺度街谷和西部的研究偏少;研究方法以统计分析、遥感和GIS的融合应用为主,数值模拟方法应用较少;城市规划与环境保护、空气污染与影响是研究热点,城市形态测度指标、城市形态对空气质量影响因素、相关性分析是主要的研究内容;土地审批、交通排放、人口分布、城市设计、植被覆盖是缓解空气污染的重要途径。展开更多
文摘The accelerated growth of the vehicular fleet, the modernization of large urban centers, and the few adjustments to the road network in Fortaleza have intensified the problems of traffic and emissions of atmospheric pollutants, highlighting the necessity for strategic urban planning initiatives to address the escalating issues of traffic and pollution. With the objective of analyzing the indices of concentrations of atmospheric pollutants and estimating how these levels can affect human health, this work consists of a study of the analysis of air quality in the intense trade region of Fortaleza. For this, the analysis zone was divided into three perimeters (Major - Medium - Minor), where each perimeter was analyzed at 7 am, 12 noon and 5 pm. Concentrations of the type of O<sub>3</sub>, particulate matter (PM<sub>2.5</sub> and PM<sub>10</sub>), CO<sub>2</sub> and HCHO were collected. Our results demonstrate that most of the analyses are within the limits of current legislation;however, at certain times and perimeters, the analyses of CO<sub>2</sub> and HCHO exceeded the established limits. In view of the above, we conclude that public policies to control air quality are necessary to reduce the damage to human health and the environment caused by pollutants.
文摘The influence of reduction in emissions on the inherent temporal characteristics of PMand NOconcentration time series in six urban cities of India is assessed by computing the Hurst exponent using Detrended Fluctuation Analysis(DFA) during the lockdown period(March 24–April 20, 2020) and the corresponding period during the previous two years(i.e., 2018 and 2019). The analysis suggests the anticipated impact of confinement on the PMand NOconcentration in urban cities, causing low concentrations. It is observed that the original PMand NOconcentration time series is persistent but filtering the time series by fitting the autoregressive process of order 1 on the actual time series and subtracting it changes the persistence property significantly. It indicates the presence of linear correlations in the PMand NOconcentrations. Hurst exponent of the PMand NOconcentration during the lockdown period and previous two years shows that the inherent temporal characteristics of the short-term air pollutant concentrations(APCs) time series do not change even after withholding the emissions. The meteorological variations also do not change over the three time periods. The finding helps in developing the prediction models for future policy decisions to improve urban air quality across cities.
文摘This paper takes a comprehensive view at transportationrelated air pollution problems and solution options. While the transport infrastructure in major Chinese cities is briefed, the environmental impacts of transport activities on urban air quality are discussed in detail. Not only the contribution of automotive emissions to the CO, NMHC and NO\-x pollution in urban areas is reviewed, but also concerns over the carcinogenic emissions, lead deposition and noise are presented. From a lifecycle view point, the impacts of motorway construction, as well as those from scrapped cars, car batteries and old tires in China have been taken into account. In the second part of this paper, the current technical efforts to curb vehicular emissions are evaluated. The performances of unleaded petrol, domestic catalytic converters, and fuel injection systems have been assessed. Options of cleaner alternative fuels and “green” vehicles are discussed, with both the life-cycle impacts and economic feasibility emphasized. Policy and management aspects for effective pollution control are tackled. In particular, speculations about potential economic incentives and legislative measures for vehicular pollution control are presented.
文摘Urban areas around the world, particularly in emerging nations such as China, India, and Brazil are experiencing high levels of air pollution due to increased population, economy, spending, and consumption, all of which contribute to deterioration in environmental and public health conditions in urban areas. This paper briefly discusses important sources of air pollution, air pollutants of concern, public health impacts, and proposed strategies to combat urban air pollution and promote sustainable urban living. A team of researchers under the mentorship of the main author is working on a number of air quality projects that involve air quality monitoring (sources, ambient, indoor, and occupational), emissions modeling, atmospheric dispersion modeling, air pollution control, and development of knowledge-based systems to manage air quality.? This paper presents potential strategies that could help address the growing public health concerns in urban areas and promote sustainable and healthy living.
文摘In this study, a new method for a comprehensive evaluation of air quality in urban agglomerations was developed based on a prototype used to solve the spatial Steiner-Weber point. With this method, the air quality information of each city in the city group is aggregated into an optimal gathering point, and then the air quality of the city group is then dynamically evaluated each year. According to the relevant data of the China Statistical Yearbook 2018, we applied this method to aggregate the air quality indices of the major cities in the Beijing-Tianjin-Hebei urban agglomeration from 2014 to 2017. Using the plant growth simulation algorithm (PGSA), the optimal assembly points were calculated to be of a higher accuracy, compared to the traditional mean value aggregation method. Finally, the air quality of the Beijing-Tianjin-Hebei urban agglomeration during each year was evaluated dynamically based on the obtained assembly points. The results show that the air quality of the urban agglomeration is ranked as follows: <span>Y2016<img src="Edit_28ddcae1-12ec-4d20-a4e9-77309c996766.bmp" alt="" /></span><span></span><span>Y2015<img src="Edit_5f164e96-55aa-4e37-98e1-6833665979d1.bmp" alt="" /></span><span></span><span>Y2017<img src="Edit_cfc0da49-7e3a-4aa8-82ac-ede99621d1ec.bmp" alt="" /></span><span></span><span>Y2014.</span>
文摘Various postulations on the relationship between urban morphology and air quality are qualitative.This fails to establish the strength of the contributions of each morphological parameter in the spatial distribution of the air quality.It is this gap in knowledge that this study sought to fill by modelling the correlation existing between the urban morphological variables of development density,land uses,biomass index and air quality values of Nairobi city.While 30 development zones of the city constituted the target population,IKONOS satellite imagery of the city for the year 2015 was utilised in establishing the development densities,land uses and biomass index.The parameters were transformed into numerical surrogates ranging from 1 to 10 with lower values accorded to zones with low biomass index,the highest development density,noxious land uses,high gaseous concentrations and vice-versa.Pearson’s correlation coefficients(r),coefficients of determination(R),t-tests and the Analysis of Variance(F-tests)with levels of significance being 95%were used to determine the strengths,significances and consistencies of the established relationships.The study established that development density is the most significant morphological variable influencing the distribution of air quality.This is followed by biomass index and to a weaker extent,land uses.
文摘A monitoring campaign of BTEX (benzene, toluene, ethylbenzene, o- m- and p-xylene) was carried out nearby two tunnel portals in the urban area of Naples with the aim to verify air quality in this kind of urban sites. Sampling was carried out using the active adsorption technique. Sampling time was 1 h. Ambient temperature and traffic flow measurements were carried out during each sampling operation. The results indicate that average benzene concentrations at both sites exceed the limit value of 10 μg/Nm^3 established by the European Community (EC) (Dir. 2000/69). Concentration levels of other BTEX are relatively high as well. A correlation between BTEX concentration and two wheeler vehicle flow was observed.
文摘As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality exceedances, common in large cities across Europe, particularly for NO2. Modeling air quality in urban areas is rather complex since observed concentration values are a consequence of the interaction of multiple sources and processes that involve a wide range of spatial and temporal scales. Besides a consistent and robust multi-scale modeling system, comprehensive and flexible emission inventories are needed. This paper discusses the application of the WRF-SMOKE-CMAQ system to the Madrid city (Spain) to assess the contribution of the main emitting sectors in the region. A detailed emission inventory was compiled for this purpose. This inventory relies on bottom-up methods for the most important sources. It is coupled with the regional traffic model and it makes use of an extensive database of industrial, commercial and residential combustion plants. Less relevant sources are downscaled from national or regional inventories. This paper reports the methodology and main results of the source apportionment study performed to understand the origin of pollution (main sectors and geographical areas) and define clear targets for the abatement strategy. Finally the structure of the air quality monitoring is analyzed and discussed to identify options to improve the monitoring strategy not only in the Madrid city but the whole metropolitan area.
文摘ADMS-Urban is the most widely used advanced dispersion model for urban areas, being used extensively in China and worldwide, providing a practical tool for assessing and managing urban air quality. In this paper we briefly describe the ADMS dispersion models and give an overview of their use in China. And it describes in more detail the use of ADMS-Urban in Fushun in Liaoning province and in Jinan in Shangdong province respectively, for studies of urban air quality. Finally the conclusions are presented.
基金funded by the National Basic Research Program of China (Grant No.2014CB447900)Xiaofeng GUO acknowledges the support of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences (Grant No.LAPC-KF-2009-02)
文摘Based on measurements at the Beijing 325-m Meteorological Tower,this study reports an analysis of atmospheric stability conditions and turbulent exchange during consecutive episodes of particle air pollution in Beijing(China),primarily due to haze and dust events(15–30 April 2012).Of particular interest were relevant vertical variations within the lower urban boundary layer(UBL).First,the haze and dust events were characterized by different atmospheric conditions,as quite low wind speed and high humidity are typically observed during haze events.In addition,for the description of stability conditions,the bulk Richardson number(RiB) was calculated for three different height intervals: 8–47,47–140,and 140–280 m.The values of RiB indicated an apparent increase in the occurrence frequency of stably-stratified air layers in the upper height interval—for the 140–280-m height interval,positive values of RiB occurred for about 85% of the time.The downward turbulent exchange of sensible heat was observed at 280 m for the full diurnal cycle,which,by contrast,was rarely seen at 140 m during daytime.These results reinforce the importance of implementing high-resolution UBL profile observations and addressing issues related to stably-stratified flows.
文摘Freely available data of sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM) observed in Arctic cities (north of 59.99 N) between 1972 and 2016 were compiled into an air-quality inventory of samples taken for limited periods. For cities with multiple years of data, air-quality climatology was determined in terms of daily means in the annual course. Mean urban air-quality climatology was calculated for regions of similar insolation, emission standards, topography, Köppen-Geiger classification, and city size. Urban concentrations of PM precursors (SO2, NH3, NO2), PM2.5 and PM10 (PM with diameter less than 2.5 and 10 μm) were assessed in the sense of climatology with evidence from current knowledge. Typically, annual SO2 and NO2 means were lower for small than large Arctic cities, but can vary more than an order of magnitude over short distance. Cities seeing seasonal sea-ice had W-shaped mean annual courses of daily O3, while other cities had a spring maximum. Typically, annual means of urban pollutants in North America exceeded those in Scandinavia except for O3, where the opposite was true. Annual mean urban PM2.5 and PM10 concentrations varied from 1.6 to 21.2 μg·m-3 and 2 to 18.2 μg·m-3, respectively. Since PM10 encompasses PM2.5, annual PM10 means must be at least 21.2 μg·m-3. According to rural-to-urban ratios of species, seasonal transport of pollutants from wildfires, shipping, and the Kola Peninsula mining area occurred at some sites in Interior Alaska, western and northern Norway, respectively. Concurrent SO2 and PM or NO2 and PM measurements revealed combustion or traffic as major contributors to urban concentrations. Recommendations for potential future measurements of Arctic urban air quality were given based on the assessments of climatology and inventory.
基金Supported by Yunnan Provincial Natural Science Foundation(2011FB009)Scientific Research Fund of Yunnan Provincial Education Department (2012Y485)
文摘[ Objective] The research aimed to study variation of the urban heat island (UHI) intensity and its relationships with air pollutants in Kunming. [ Method] Observation data of the air temperature series from Kunming station and surrounding Taihuashan meteorological station were used to investigate the variation characteristics of UHI intensity in Kunming during 2001 -2010. Meanwhile, relationship between UHI intensity and air quality on the basis of concentration data for primary air pollutants (SO2, NO2 and PMlo ) from environmental monitoring station of Kunming was studied in this paper. [Result] Annual mean UHI intensity increased at the rate of 0.110 ℃/10 a, and UHI intensity was higher in dry season than that in rainy season. The change trend of air pollutants level in Kunming was in accordance with that of the UHI intensity. When UHI intensity reached peak value, air pollutants showed high concentration. UHI intensity had significantly positive correlation with air pollutants level. Annual mean UHI intensity had significantly positive correlation with PMlo level under the likelihood of 95%, but monthly mean UHI intensity had significantly positive correlation with NO2 level under the likelihood of 99%. In addition, annual statistics days with Grade I air quality obviously decreased with the strengthenment of UHI intensity. Therefore, air quality in Kunming City tumed more deteriorated with the enhancement of UHI intensity. [ Conclusion] The research findings provided a valid scientific basis for the mitigation of UHI and improvement of the atmospheric environment in Kunming.
文摘Rwanda is a landlocked republic in Equatorial Africa. The capital Kigali (1°57'S, 30°04'E) can be mentioned as a typical African city due to its rising population and the rising rate of motorization. Different pollutants produced e.g. by a highusage rate of mopeds or open fireplaces burning wood for cooking and household chores could be detected. Climatological parameters as well as air pollutants were measured within the urban area. Additionally, highly frequented spatial and temporal mobile measurements of particulate matter were taken during different dry seasons regarding different conditions. These values indicated an urban heat island, which tended to rise for the last four decades. A temporary phenomenon for the air pollution indicators is visible during clear and calm weather situations, e.g. the distinctive relief caused an accumulation within small valleys called “Marais” in the night time. Unfortunately, these are the favourite places for living and agriculture. So there is no infrequence in values of PM10 > 1.000 μg·m-3. The origin of the different airborne particles was verified by using a scanning electron microscope and it could be mentioned that most particles were from the combustion of biomass and traffic.
文摘Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric power plants enter the lungs and pollute the blood of urban residents leading to a burden of disease with more than 3 million premature deaths per year attributed to outdoor air pollution. Welfare losses including premature deaths associated with air pollution were about $5 trillion in 2013. A global transition to electric vehicles, and the generation of electricity without combustion emissions would improve air quality significantly and reduce greenhouse gas emissions. This transition is in progress in many parts of the world with more than 2 million electric vehicles in service in 2017. Electric bus and electric taxi sales are increasing, and many large cities have multiple programs to improve air quality. When health costs are considered, it is very appropriate for communities to take action to improve air quality and health. This work reviews and reports many positive actions that are in progress in larger cities.
文摘近年来城市形态对空气质量的影响研究引起了国内学者的广泛关注,获得了大量研究成果,但仍然缺乏系统梳理。作者以中国期刊全文数据库(CNKI)和美国科学情报研究所Web of Science核心合集为数据源,采用文献归纳法和CiteSpace软件,对2000至2022年发表的我国城市形态对空气质量影响的文献进行了系统分析。研究发现:年度发文量整体呈上升趋势,2017年后英文文献发文量高于中文文献量,中英文研究机构重合度较低,缺少合作研究;研究主要以区域尺度和局地尺度为主,微观尺度街谷和西部的研究偏少;研究方法以统计分析、遥感和GIS的融合应用为主,数值模拟方法应用较少;城市规划与环境保护、空气污染与影响是研究热点,城市形态测度指标、城市形态对空气质量影响因素、相关性分析是主要的研究内容;土地审批、交通排放、人口分布、城市设计、植被覆盖是缓解空气污染的重要途径。