The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast deve...The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast developing and uncontrolled urbanization is behind the development of some negative side effects on the urban environment. Many studies demonstrate the ability of remote sensing and GIS （geographic information system） to monitor urban environment quality. Casablanca, Morocco＇s economical capital is facing a fast growing demographic development amplified by a massive rural depopulation and all this in an anarchic way. This growth of increased urban activity comes often with the proliferation of informal settlement and shantytown to the detriment of farming areas and green spaces. This study is made possible by using a SPOT-5 image of Casablanca city, taken March 16, 2004 merged with 2.5 m spatial resolution and census data. Indicators were defined and listed in social, economic and environmental categories. An index of environmental quality in Casablanca city for the 17 urban municipalities was calculated after the standardization and weighting of indicators used. The results may be useful to city managers and planners who are concerned with urban environment quality issues and sustainable development.展开更多
Urbanization development quality(UDQ) of urban agglomeration(UA) is one of the important indexes to evaluate if the UA urbanization speed is reasonable,if the population urbanization process is sound,if the economic u...Urbanization development quality(UDQ) of urban agglomeration(UA) is one of the important indexes to evaluate if the UA urbanization speed is reasonable,if the population urbanization process is sound,if the economic urbanization process is efficient,if the social urbanization process is harmonious and fair,which is generally composed of three parts,including economic urbanization development quality,social urbanization development quality and spa-tial urbanization security quality.With the research of evolution rules of UDQ,through the analysis on the interactive coordination relation between UDQ and urbanization level,the paper proposes three dimensional index ball and stan-dard value of comprehensive measures of UDQ,which is composed of three categories of indexes.By introducing At-kinson model,this paper constructs the sub-element measure model and segmental measure model of UDQ,and fur-ther makes an overall evaluation on the characteristic of UDQ of UAs in China.Results show that:1) UDQ of UAs lied at optimization and upgrading phase during 1995-2008 and the quality was low.Population urbanization level did not reflect the UDQ of UAs;2) the improving speed of the spatial urbanization security quality was higher than the so-cial urbanization development quality,and the improving speed of economic urbanization development quality was the lowest;3) the coordination between UDQ and urbanization level was not so good;4) there was a weak correlation re-lation between UDQ and UA scale,and it was not true that the bigger the UA was,the better the UDQ was.展开更多
Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have stu...Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4. The relation model between urban underlying surface temperature (UUST) and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City . Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection.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
The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations w...The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations where the air quality does not comply with the limit values and to assess possible emission reduction measures to decrease concentration levels. The Portuguese agglomeration of Porto Litoral is one of the several European Union urban areas that had to develop and implement AQPs to reduce particulate matter （PM10）. The AQPs were initially designed based on a scenario approach and using an air quality model, which was applied over the study region for the reference situation with the current PM10 emissions, and for a reduction scenario with PM10 emissions re-estimated considering the implementation of abatement measures. Aiming to cost-efficiently optimize Porto Litoral PM10 abatement measures, the assessment procedure was repeated using an optimization approach based on the RIAT ＋ （regional integrated assessment tool ＋）. Porto Litoral urban area＇s technical and non-technical measures were characterized （including associated costs） and, through the application of the air quality model to 20 emissions abatement scenarios, S-R （source-receptor） relationships were created. This paper comparatively describes the air quality plans designed to improve PM10 levels in the Porto Litoral agglomeration based on both the scenario analysis and the optimization approach.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
Based on sustainable development theory and the UN's Human Development Index, this thesis puts forward what the quality of urban life implies, makes a study of the world Expo's potential influences on the urba...Based on sustainable development theory and the UN's Human Development Index, this thesis puts forward what the quality of urban life implies, makes a study of the world Expo's potential influences on the urban life of Shanghai and advances the strategy and measures to strengthen the life-quality-facing urban展开更多
This paper presents an assessment of air quality of the Kathmandu valley, capital city of Nepal. This is the largest urbanized area in the country of about 300 km2. In the last two decades an intensive development of ...This paper presents an assessment of air quality of the Kathmandu valley, capital city of Nepal. This is the largest urbanized area in the country of about 300 km2. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degradation. In order to evaluate the urban air quality in Kathmandu, a field monitoring network for particle deposition, nitrogen dioxide （NO2） and sulphur dioxide （SO2） by passive sampling with high space resolution was implemented in co-operation with IVL-Sweden. The net work composed of 60 monitoring sites distributed in a grid of 1 × 1 km2 covering all over the main city and some rural valley. Monitoring were carried out for two seasons, rainy and dry as two campaign monitoring. The diffusive samplers were prepared and analyzed in IVL, Sweden. Good agreements in particle deposition between the two campaigns were observed. The particle deposition to the surrogate surface varied between 3 and 608 μg@cm2·monthl for the monitoring periods. The NOz concentrations on the other hand were quite similar in the two campaigns, and the SO2 concentrations were much lower in the first campaign compared to the second. The ranges of NO2 and SO2 concentrations were found to be from 5.6 to 52.6 μg/m3 and 0.6 to 23.4 μg·m-3 respectively. Arc Info/Arc map GIS 9.2 software was used for production of maps of spatial distribution of all the three parameters in the valley. Seasonal variation and traffic influence were also studied. Local meteorological effects in the distribution of pollutants were clearly observed and the NO2 concentrations were strictly related with traffic intensity.展开更多
Obesity and global warming are two major challengesthat affect communities’health and quality of life.Providing good walking environments,with appropriate pedestrian infrastructure,green areas and access to commercia...Obesity and global warming are two major challengesthat affect communities’health and quality of life.Providing good walking environments,with appropriate pedestrian infrastructure,green areas and access to commercial retail and transport hubs favour liveable,healthy,and sustainable cities.The Lisbon City Hall has implemented an intervention program in the public space as a strategy to improve environmental quality and mitigate the effects of climate change.The program“A square in each neighbourhood”intends not only to reinforce the economic base of Lisbon,namely tourism,restaurants,commerce,and creative activities but also to promote physical activity and improve the quality of living of all citizens.For studying the impact of the public space quality on the walking environment,Campolide,a typical Lisbon neighbourhood,Portugal,which includes one of the requalified squares,was selected.A two-step methodology based on spatial modelling is proposed.In the first step,the public space quality was evaluated based on a set of 13 urban quality attributes.Attributes,intended for the street level,were collected from open data platforms and complemented with a field survey.Then,through spatial analysis,these attributes were used to build the Pedestrian Environment Quality Indicator and the Priority Intervention Indicator.Using these indicators,walking-friendly streets were mapped and the most critical sites that require priority intervention were identified to prepare for the requalification planning process.The street with the highest quality in the study area according to the dimensions evaluated-connectivity,convenience,comfort,cleanliness,and conviviality-has a great offer of trees,bus stops,commercial establishments,commercial diversity,crossings,paper bins/eco points and esplanades.On the opposite side of the rank,the street with the lowest quality has no trees or green areas,transport stops,benches and tables,or commercial activity.The urban quality indicators constitute a helpful tool for city planners and policymakers when planning sustainable living neighbourhoods.展开更多
Support vector regression （SVR） method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study...Support vector regression （SVR） method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels. The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the most suitable parameters （insensitive loss function e, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ） are 0.001, 0.5, and 2 000, respectively.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
Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, g...Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, gross pollutants also contributes to degradation of river water quality and loss of aquatic habitat as it carries harmful pollutants such as oxygen demanding material, hydrocarbons and heavy metals. This study analyzed trend of gross pollutant generated from two urban residential areas located in Selangor, Malaysia. The median value of gross pollutant load obtained fi＇om the Amanah Apartment and Bandar Botanic are 347.41 kg/ha/year and 32.46 kg/ha/year, respectively. Relationship between gross pollutant wet load with rainfall depths was derived using regression equation. A significant trend of increasing gross pollutant wet load into drainage system with increasing rainfall depth was observed. The behavior of pollutant load is related to the one observed in Australia.展开更多
Air pollution is a serious problem brought by the rapid urbanization and economic development in China, imposing great challenges and threats to population health and the sustainability of the society. Based on the re...Air pollution is a serious problem brought by the rapid urbanization and economic development in China, imposing great challenges and threats to population health and the sustainability of the society. Based on the real-time air quality monitoring data obtained for each Chinese city from 2013 to 2014, the spatiotemporal characteristics of air pollution are analyzed using various exploratory spatial data analysis tools. With spatial econometric models, this paper further quantifies the influences of socioeconomic factors on air quality at both the national and regional scales. The results are as follows： （1） From 2013 to 2014, the percentage of days compliance of urban air quality increased but air pollution deteriorated and the worsening situation in regions with poor air quality became more obvious. （2） Changes of air quality show a clear temporal coupling with regional socioeconomic activities, basically ＂relatively poor at daytime and relatively good at night＂. （3） Urban air pollution shows a spatial pattern of ＂heavy in the east and light in the west, and heavy in the north and light in the south＂. （4） The overall extent and distribution of regional urban air pollution have clearly different characteristics. The formation and evolution of regional air pollution can be basically induced as ＂the pollution of key cities is aggravated--pollution of those cities spreads-- regional overall pollution is aggravated--the key cities lead in pollution governance--regional pollution joint prevention and control is implemented--regional overall pollution is reduced＂. （5） At the national level, energy consumption, industrialization and technological progress are the major factors in the worsening of urban air quality, economic development is a significant driver for the improvement of that quality. （6） Influenced by resources, environment and the development stage, the socioeconomic factors had strongly variable impacts on air quality, in both direction and intensity in different regions. Based on the conclusion, the regional differ- entiation and development idea of the relationship between economic development and en- vironmental changes in China are discussed.展开更多
It is of great theoretical and practical importance to carry out research on the spatio-temporal evolution of urban air pollution and its driving forces,which helps to facilitate a deeper understanding of the mutual f...It is of great theoretical and practical importance to carry out research on the spatio-temporal evolution of urban air pollution and its driving forces,which helps to facilitate a deeper understanding of the mutual feedback mechanisms between the urban environment and socio-economic systems.Comprehension of these mechanisms will contribute to the design and implementation of efficient environmental policies that ultimately will improve the quality of urbanization development.This paper illustrates the spatio-temporal evolutionary characteristics of six urban ambient air pollutant concentrations,namely,CO,NO_(2),O_(3),PM_(10),PM_(2.5),SO_(2),in 286 sample cities above the prefecture level in China from 2014 to 2019.The interactions between the pollutant concentrations are analyzed based on panel regression models.A random forest model is then employed to explore the correlations between the concentrations of these six pollutants and 13 natural and socio-economic impact factors to isolate the most crucial ones.The results reveal three aspects.First,within the research period,the average annual concentration of O_(3)increased while that of other pollutants decreased year by year.Second,there were significant interactions between concentrations of the six pollutants,leading to obvious compound air pollution in urban areas.Third,the impact of natural and socio-economic factors on urban air quality varied greatly among different air pollutants,with air temperature,vegetation coverage,urbanization level and traffic factors ranking high and the different response thresholds to the dominant influencing factors.In light of the limited ability of humans to control the natural environment and meteorological conditions,it is recommended that urban air quality be further improved by optimizing urban density,controlling anthropogenic emission sources,and implementing strict air pollution prevention and control measures.展开更多
Effectively monitoring urban air quality,and analyzing the source terms of the main atmospheric pollutants is important for public authorities to take air quality management actions.Previous works,such as long-term ob...Effectively monitoring urban air quality,and analyzing the source terms of the main atmospheric pollutants is important for public authorities to take air quality management actions.Previous works,such as long-term obser-vations by monitoring stations,cannot provide customized data services and in-time emergency response under urgent situations(gas leakage incidents).Therefore,we first review the up-to-date approaches(often machine learning and optimization methods)with respect to urban air quality monitoring and hazardous gas source anal-ysis.To bridge the gap between present solutions and practical requirements,we design a conceptual framework,namely MAsmed(Multi-Agents for sensing,monitoring,estimating and determining),to provide fine-grained concentration maps,customized data services,and on-demand emergency management.In this framework,we leverage the hybrid design of wireless sensor networks(WSNs)and mobile crowdsensing(MCS)to sense urban air quality and relevant data(e.g.traffic data,meteorological data,etc.);Using the sensed data,we can create a fine-grained air quality map for the authorities and relevant stakeholders,and provide on-demand source term estimation and source searching methods to estimate,seek,and determine the sources,thereby aiding decision-makers in emergency response(e.g.for evacuation).In this paper,we also identify several potential opportunities for future research.展开更多
Based on the gains and losses learned from the experience of the world urbanization over the last two centuries,this paper first of all evaluates China's urbanization quality at both the provincial and municipal l...Based on the gains and losses learned from the experience of the world urbanization over the last two centuries,this paper first of all evaluates China's urbanization quality at both the provincial and municipal levels. It then puts forward connotations of the new-type urbanization with Chinese characteristics which concern five aspects: the people-oriented principle,the interactions among industrialization,informatization,urbanization,and agricultural modernization,ecological civilization,rational layout,and culture promotion. It further predicts the economic and urbanization growth rates,the proportions of the primary,secondary,and tertiary industries,and the migrant population in future from the perspectives of the baseline,optimistic,and stable development scenarios,proposing that the Sciences of Human Settlements will play an important role in the process of the new-type urbanization.展开更多
Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this ...Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this study the impact of using two traditional land use classifications, the United States Geological Survey (USGS) and the Moderate-resolution Imaging Spectroradiometer (MODIS), were evaluated. The Weather Research and Forecasting model (WRF, version 3.2.1) was run for the period 18 - 22 August, 2014 (dry season) at a grid spacing of 3 km centered on the city of Manaus. The comparison between simulated and ground-based observed data revealed significant differences in the meteorological fields, for instance, the temperature. Compared to USGS, MODIS classification showed better skill in representing observed temperature for urban areas of Manaus, while the two files showed similar results for nearby areas. The analysis of the files suggests that the better quality of the simulations favorable to the MODIS file is straightly related to its better representation of urban class of land use, which is observed to be not adequately represented by USGS.展开更多
Urbanization interacts with land use through resource consumption and space en-croachment.Clarifying the spatial correlations of the interactive relationship between urbaniza-tion and land use,along with their spatiot...Urbanization interacts with land use through resource consumption and space en-croachment.Clarifying the spatial correlations of the interactive relationship between urbaniza-tion and land use,along with their spatiotemporal dynamics,is of vital importance for address-ing the complex interplay between urban development and land resources and identifying re-gional differences.However,previous studies have not sufficiently explored these issues.Herein,we introduce a coupling coordination degree(CCD)model and present the results of exploratory spatiotemporal analyses involving in-depth investigation of the CcD between ur-banization quality and land-use intensity in 290 Chinese cities.The results demonstrate that the CcD for most cities was at the transition-period or basic-coordination stage.The dynamics of the spatial correlation of the CCD was found to increase from the east to the central and west-ern regions,but this was found to decline overall.The movement direction and spatial de-pendence of the local spatial structure of the CcD exerted a dominant synergistic effect.The transition of the spatial correlation was mainly Type I(stable local and neighboring morphology),showing strong transfer inertia,path dependence,and locking features.Dynamic transitions occurred more in central and eastern cities.The results suggest that more cross-city coopera-tion could contribute to moderate land-resource exploitation for high-quality urbanization.展开更多
With rapid urbanization and energy consumption, environmental pollution and degradation have become increasingly serious problems in China. At the beginning of 2013, China implemented new ambient air quality standards...With rapid urbanization and energy consumption, environmental pollution and degradation have become increasingly serious problems in China. At the beginning of 2013, China implemented new ambient air quality standards（GB 3095-2012） in which the concentration of six pollutants including PM2.5, ozone, carbon monoxide, PM10, sulfur dioxide and nitrogen dioxide were monitored. This study gathered annual air pollutant concentration data for the six pollutants in 113 key environmental protection cites throughout China in 2014 and 2015 to explain spatial patterns of urban air pollution. Based on the Kernel density estimation method, spatial hotspots of air pollution were illustrated through which spatial cluster of each pollutants could be plotted. By employing an entropy evaluation system, urban air quality was assessed in terms of the six atmospheric pollutants. We conclude that, in general, CO and SO2 were two important pollutants in most Chinese cities, but this varied greatly among cities. The assessment results indicate that cities with the worst air quality were mainly located in northern and central provinces, dominantly in the Beijing-Tianjin-Hebei metropolitan area. Regression modeling showed that a combination of meteorological factors and human-related determinants, to say specifically, industrialization and urbanization factors, greatly influenced urban air quality variation in China. Results from spatial lag regression modeling confirmed that air pollution existed obvious spatial spillover effects among key cities. The spatial interdependence effects of urban air quality means that Chinese municipal governments should strengthen regional cooperation and deepen bilateral collaboration in terms of air regulation and pollution prevention.展开更多
During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect ...During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions （0.5-20μm） obtained using an aerodynamic particle sizer （model 3321, TSI, USA） in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 μm were （15.0±2.1） cm-3, （11.8±2.6） μm2/cm3 and （1.9±0.6） μm2/cm3, respectively, on the traffic-restricted day （Sunday）, which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 μm. Number and volume concentrations of particles in size range 0.5-1.0μm correlated well with the number of non-CNG （Compressed Natural Gas） powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.展开更多
文摘The urban environmental quality remains currently difficult to be assessed because of overlapping of several natural and anthropogenic factors having socio-economic and environmental outstanding impacts. The fast developing and uncontrolled urbanization is behind the development of some negative side effects on the urban environment. Many studies demonstrate the ability of remote sensing and GIS （geographic information system） to monitor urban environment quality. Casablanca, Morocco＇s economical capital is facing a fast growing demographic development amplified by a massive rural depopulation and all this in an anarchic way. This growth of increased urban activity comes often with the proliferation of informal settlement and shantytown to the detriment of farming areas and green spaces. This study is made possible by using a SPOT-5 image of Casablanca city, taken March 16, 2004 merged with 2.5 m spatial resolution and census data. Indicators were defined and listed in social, economic and environmental categories. An index of environmental quality in Casablanca city for the 17 urban municipalities was calculated after the standardization and weighting of indicators used. The results may be useful to city managers and planners who are concerned with urban environment quality issues and sustainable development.
基金Under the auspices of National Natural Science Foundation of China (No. 40971101)Key Direction in Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-321-05)
文摘Urbanization development quality(UDQ) of urban agglomeration(UA) is one of the important indexes to evaluate if the UA urbanization speed is reasonable,if the population urbanization process is sound,if the economic urbanization process is efficient,if the social urbanization process is harmonious and fair,which is generally composed of three parts,including economic urbanization development quality,social urbanization development quality and spa-tial urbanization security quality.With the research of evolution rules of UDQ,through the analysis on the interactive coordination relation between UDQ and urbanization level,the paper proposes three dimensional index ball and stan-dard value of comprehensive measures of UDQ,which is composed of three categories of indexes.By introducing At-kinson model,this paper constructs the sub-element measure model and segmental measure model of UDQ,and fur-ther makes an overall evaluation on the characteristic of UDQ of UAs in China.Results show that:1) UDQ of UAs lied at optimization and upgrading phase during 1995-2008 and the quality was low.Population urbanization level did not reflect the UDQ of UAs;2) the improving speed of the spatial urbanization security quality was higher than the so-cial urbanization development quality,and the improving speed of economic urbanization development quality was the lowest;3) the coordination between UDQ and urbanization level was not so good;4) there was a weak correlation re-lation between UDQ and UA scale,and it was not true that the bigger the UA was,the better the UDQ was.
基金Under the auspices of the National Natural Science Foundation of China (No.40001008).
文摘Urban heat environmental quality (UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4. The relation model between urban underlying surface temperature (UUST) and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City . Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection.
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The air quality directive （2008/50/EC （of the European Parliament and of the Council of 21 May 2008）） requires European Member States to design appropriate AQPs （air quality plans） for zones and agglomerations where the air quality does not comply with the limit values and to assess possible emission reduction measures to decrease concentration levels. The Portuguese agglomeration of Porto Litoral is one of the several European Union urban areas that had to develop and implement AQPs to reduce particulate matter （PM10）. The AQPs were initially designed based on a scenario approach and using an air quality model, which was applied over the study region for the reference situation with the current PM10 emissions, and for a reduction scenario with PM10 emissions re-estimated considering the implementation of abatement measures. Aiming to cost-efficiently optimize Porto Litoral PM10 abatement measures, the assessment procedure was repeated using an optimization approach based on the RIAT ＋ （regional integrated assessment tool ＋）. Porto Litoral urban area＇s technical and non-technical measures were characterized （including associated costs） and, through the application of the air quality model to 20 emissions abatement scenarios, S-R （source-receptor） relationships were created. This paper comparatively describes the air quality plans designed to improve PM10 levels in the Porto Litoral agglomeration based on both the scenario analysis and the optimization approach.
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Based on sustainable development theory and the UN's Human Development Index, this thesis puts forward what the quality of urban life implies, makes a study of the world Expo's potential influences on the urban life of Shanghai and advances the strategy and measures to strengthen the life-quality-facing urban
文摘This paper presents an assessment of air quality of the Kathmandu valley, capital city of Nepal. This is the largest urbanized area in the country of about 300 km2. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degradation. In order to evaluate the urban air quality in Kathmandu, a field monitoring network for particle deposition, nitrogen dioxide （NO2） and sulphur dioxide （SO2） by passive sampling with high space resolution was implemented in co-operation with IVL-Sweden. The net work composed of 60 monitoring sites distributed in a grid of 1 × 1 km2 covering all over the main city and some rural valley. Monitoring were carried out for two seasons, rainy and dry as two campaign monitoring. The diffusive samplers were prepared and analyzed in IVL, Sweden. Good agreements in particle deposition between the two campaigns were observed. The particle deposition to the surrogate surface varied between 3 and 608 μg@cm2·monthl for the monitoring periods. The NOz concentrations on the other hand were quite similar in the two campaigns, and the SO2 concentrations were much lower in the first campaign compared to the second. The ranges of NO2 and SO2 concentrations were found to be from 5.6 to 52.6 μg/m3 and 0.6 to 23.4 μg·m-3 respectively. Arc Info/Arc map GIS 9.2 software was used for production of maps of spatial distribution of all the three parameters in the valley. Seasonal variation and traffic influence were also studied. Local meteorological effects in the distribution of pollutants were clearly observed and the NO2 concentrations were strictly related with traffic intensity.
基金This work was financed by national funds through FCT-Foundation for Science and Technology,I.P.,within the scope of the project“UIDB/04647/2020”of CICS.NOVA-Interdisciplinary Centre of Social Sciences from Universidade NOVA de LisboaThe first author was financed by national funds through the FCT,under the Norma Transitória-DL 57/2016/CP1453/CT0004.
文摘Obesity and global warming are two major challengesthat affect communities’health and quality of life.Providing good walking environments,with appropriate pedestrian infrastructure,green areas and access to commercial retail and transport hubs favour liveable,healthy,and sustainable cities.The Lisbon City Hall has implemented an intervention program in the public space as a strategy to improve environmental quality and mitigate the effects of climate change.The program“A square in each neighbourhood”intends not only to reinforce the economic base of Lisbon,namely tourism,restaurants,commerce,and creative activities but also to promote physical activity and improve the quality of living of all citizens.For studying the impact of the public space quality on the walking environment,Campolide,a typical Lisbon neighbourhood,Portugal,which includes one of the requalified squares,was selected.A two-step methodology based on spatial modelling is proposed.In the first step,the public space quality was evaluated based on a set of 13 urban quality attributes.Attributes,intended for the street level,were collected from open data platforms and complemented with a field survey.Then,through spatial analysis,these attributes were used to build the Pedestrian Environment Quality Indicator and the Priority Intervention Indicator.Using these indicators,walking-friendly streets were mapped and the most critical sites that require priority intervention were identified to prepare for the requalification planning process.The street with the highest quality in the study area according to the dimensions evaluated-connectivity,convenience,comfort,cleanliness,and conviviality-has a great offer of trees,bus stops,commercial establishments,commercial diversity,crossings,paper bins/eco points and esplanades.On the opposite side of the rank,the street with the lowest quality has no trees or green areas,transport stops,benches and tables,or commercial activity.The urban quality indicators constitute a helpful tool for city planners and policymakers when planning sustainable living neighbourhoods.
基金Projects(2007JT3018, 2008JT1013, 2009FJ4056) supported by the Key Project in Hunan Science and Technology Program, ChinaProject(20090161120014) supported by the New Teachers Sustentation Fund in Doctoral Program, Ministry of Education, China
文摘Support vector regression （SVR） method is a novel type of learning machine algorithms, which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels. The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the most suitable parameters （insensitive loss function e, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ） are 0.001, 0.5, and 2 000, respectively.
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.
文摘Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, gross pollutants also contributes to degradation of river water quality and loss of aquatic habitat as it carries harmful pollutants such as oxygen demanding material, hydrocarbons and heavy metals. This study analyzed trend of gross pollutant generated from two urban residential areas located in Selangor, Malaysia. The median value of gross pollutant load obtained fi＇om the Amanah Apartment and Bandar Botanic are 347.41 kg/ha/year and 32.46 kg/ha/year, respectively. Relationship between gross pollutant wet load with rainfall depths was derived using regression equation. A significant trend of increasing gross pollutant wet load into drainage system with increasing rainfall depth was observed. The behavior of pollutant load is related to the one observed in Australia.
基金Key Program of National Natural Science Foundation of China,No.41430636Youth Program of the Humanities and Social Science Research of Ministry of Education,No.16YJC790056
文摘Air pollution is a serious problem brought by the rapid urbanization and economic development in China, imposing great challenges and threats to population health and the sustainability of the society. Based on the real-time air quality monitoring data obtained for each Chinese city from 2013 to 2014, the spatiotemporal characteristics of air pollution are analyzed using various exploratory spatial data analysis tools. With spatial econometric models, this paper further quantifies the influences of socioeconomic factors on air quality at both the national and regional scales. The results are as follows： （1） From 2013 to 2014, the percentage of days compliance of urban air quality increased but air pollution deteriorated and the worsening situation in regions with poor air quality became more obvious. （2） Changes of air quality show a clear temporal coupling with regional socioeconomic activities, basically ＂relatively poor at daytime and relatively good at night＂. （3） Urban air pollution shows a spatial pattern of ＂heavy in the east and light in the west, and heavy in the north and light in the south＂. （4） The overall extent and distribution of regional urban air pollution have clearly different characteristics. The formation and evolution of regional air pollution can be basically induced as ＂the pollution of key cities is aggravated--pollution of those cities spreads-- regional overall pollution is aggravated--the key cities lead in pollution governance--regional pollution joint prevention and control is implemented--regional overall pollution is reduced＂. （5） At the national level, energy consumption, industrialization and technological progress are the major factors in the worsening of urban air quality, economic development is a significant driver for the improvement of that quality. （6） Influenced by resources, environment and the development stage, the socioeconomic factors had strongly variable impacts on air quality, in both direction and intensity in different regions. Based on the conclusion, the regional differ- entiation and development idea of the relationship between economic development and en- vironmental changes in China are discussed.
基金National Natural Science Foundation of China,No.41771133,No.41822104The Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA19040403。
文摘It is of great theoretical and practical importance to carry out research on the spatio-temporal evolution of urban air pollution and its driving forces,which helps to facilitate a deeper understanding of the mutual feedback mechanisms between the urban environment and socio-economic systems.Comprehension of these mechanisms will contribute to the design and implementation of efficient environmental policies that ultimately will improve the quality of urbanization development.This paper illustrates the spatio-temporal evolutionary characteristics of six urban ambient air pollutant concentrations,namely,CO,NO_(2),O_(3),PM_(10),PM_(2.5),SO_(2),in 286 sample cities above the prefecture level in China from 2014 to 2019.The interactions between the pollutant concentrations are analyzed based on panel regression models.A random forest model is then employed to explore the correlations between the concentrations of these six pollutants and 13 natural and socio-economic impact factors to isolate the most crucial ones.The results reveal three aspects.First,within the research period,the average annual concentration of O_(3)increased while that of other pollutants decreased year by year.Second,there were significant interactions between concentrations of the six pollutants,leading to obvious compound air pollution in urban areas.Third,the impact of natural and socio-economic factors on urban air quality varied greatly among different air pollutants,with air temperature,vegetation coverage,urbanization level and traffic factors ranking high and the different response thresholds to the dominant influencing factors.In light of the limited ability of humans to control the natural environment and meteorological conditions,it is recommended that urban air quality be further improved by optimizing urban density,controlling anthropogenic emission sources,and implementing strict air pollution prevention and control measures.
基金This study is supported in part by the National Natural Science Foun-dation of China under Grant Nos.62173337,21808181,72071207in part by the National Social Science Foundation of China under Grant 17CGL047.
文摘Effectively monitoring urban air quality,and analyzing the source terms of the main atmospheric pollutants is important for public authorities to take air quality management actions.Previous works,such as long-term obser-vations by monitoring stations,cannot provide customized data services and in-time emergency response under urgent situations(gas leakage incidents).Therefore,we first review the up-to-date approaches(often machine learning and optimization methods)with respect to urban air quality monitoring and hazardous gas source anal-ysis.To bridge the gap between present solutions and practical requirements,we design a conceptual framework,namely MAsmed(Multi-Agents for sensing,monitoring,estimating and determining),to provide fine-grained concentration maps,customized data services,and on-demand emergency management.In this framework,we leverage the hybrid design of wireless sensor networks(WSNs)and mobile crowdsensing(MCS)to sense urban air quality and relevant data(e.g.traffic data,meteorological data,etc.);Using the sensed data,we can create a fine-grained air quality map for the authorities and relevant stakeholders,and provide on-demand source term estimation and source searching methods to estimate,seek,and determine the sources,thereby aiding decision-makers in emergency response(e.g.for evacuation).In this paper,we also identify several potential opportunities for future research.
文摘Based on the gains and losses learned from the experience of the world urbanization over the last two centuries,this paper first of all evaluates China's urbanization quality at both the provincial and municipal levels. It then puts forward connotations of the new-type urbanization with Chinese characteristics which concern five aspects: the people-oriented principle,the interactions among industrialization,informatization,urbanization,and agricultural modernization,ecological civilization,rational layout,and culture promotion. It further predicts the economic and urbanization growth rates,the proportions of the primary,secondary,and tertiary industries,and the migrant population in future from the perspectives of the baseline,optimistic,and stable development scenarios,proposing that the Sciences of Human Settlements will play an important role in the process of the new-type urbanization.
基金This work received funding support from CNPq(National Counsel of Technological and Scientific Development,process 404104/2013-4)CAPES(Coordination for the Improvement of Higher Education Personnel)and Araucária Foundation
文摘Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this study the impact of using two traditional land use classifications, the United States Geological Survey (USGS) and the Moderate-resolution Imaging Spectroradiometer (MODIS), were evaluated. The Weather Research and Forecasting model (WRF, version 3.2.1) was run for the period 18 - 22 August, 2014 (dry season) at a grid spacing of 3 km centered on the city of Manaus. The comparison between simulated and ground-based observed data revealed significant differences in the meteorological fields, for instance, the temperature. Compared to USGS, MODIS classification showed better skill in representing observed temperature for urban areas of Manaus, while the two files showed similar results for nearby areas. The analysis of the files suggests that the better quality of the simulations favorable to the MODIS file is straightly related to its better representation of urban class of land use, which is observed to be not adequately represented by USGS.
基金National Natural Science Foundation of China,No.42371286,No.42001206National Social Science Foundation of China,No.22CJY041+1 种基金The Key Laboratory for Law and Governance of the Ministry of Natural Resources,No.CUGFP-1904School of Public Administration at China University of Geosciences,No.CUGGG-2002。
文摘Urbanization interacts with land use through resource consumption and space en-croachment.Clarifying the spatial correlations of the interactive relationship between urbaniza-tion and land use,along with their spatiotemporal dynamics,is of vital importance for address-ing the complex interplay between urban development and land resources and identifying re-gional differences.However,previous studies have not sufficiently explored these issues.Herein,we introduce a coupling coordination degree(CCD)model and present the results of exploratory spatiotemporal analyses involving in-depth investigation of the CcD between ur-banization quality and land-use intensity in 290 Chinese cities.The results demonstrate that the CcD for most cities was at the transition-period or basic-coordination stage.The dynamics of the spatial correlation of the CCD was found to increase from the east to the central and west-ern regions,but this was found to decline overall.The movement direction and spatial de-pendence of the local spatial structure of the CcD exerted a dominant synergistic effect.The transition of the spatial correlation was mainly Type I(stable local and neighboring morphology),showing strong transfer inertia,path dependence,and locking features.Dynamic transitions occurred more in central and eastern cities.The results suggest that more cross-city coopera-tion could contribute to moderate land-resource exploitation for high-quality urbanization.
基金National Natural Science Foundation of China(41771133)Science and Technology Service Project of Chinese Academy of Sciences(Technical Regulations of Urban Planning:KFJ-EW-STS-089)
文摘With rapid urbanization and energy consumption, environmental pollution and degradation have become increasingly serious problems in China. At the beginning of 2013, China implemented new ambient air quality standards（GB 3095-2012） in which the concentration of six pollutants including PM2.5, ozone, carbon monoxide, PM10, sulfur dioxide and nitrogen dioxide were monitored. This study gathered annual air pollutant concentration data for the six pollutants in 113 key environmental protection cites throughout China in 2014 and 2015 to explain spatial patterns of urban air pollution. Based on the Kernel density estimation method, spatial hotspots of air pollution were illustrated through which spatial cluster of each pollutants could be plotted. By employing an entropy evaluation system, urban air quality was assessed in terms of the six atmospheric pollutants. We conclude that, in general, CO and SO2 were two important pollutants in most Chinese cities, but this varied greatly among cities. The assessment results indicate that cities with the worst air quality were mainly located in northern and central provinces, dominantly in the Beijing-Tianjin-Hebei metropolitan area. Regression modeling showed that a combination of meteorological factors and human-related determinants, to say specifically, industrialization and urbanization factors, greatly influenced urban air quality variation in China. Results from spatial lag regression modeling confirmed that air pollution existed obvious spatial spillover effects among key cities. The spatial interdependence effects of urban air quality means that Chinese municipal governments should strengthen regional cooperation and deepen bilateral collaboration in terms of air regulation and pollution prevention.
基金supported by the Hundred Talents Program of Chinese Academy of Sciences (No. 29O827631)
文摘During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions （0.5-20μm） obtained using an aerodynamic particle sizer （model 3321, TSI, USA） in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 μm were （15.0±2.1） cm-3, （11.8±2.6） μm2/cm3 and （1.9±0.6） μm2/cm3, respectively, on the traffic-restricted day （Sunday）, which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 μm. Number and volume concentrations of particles in size range 0.5-1.0μm correlated well with the number of non-CNG （Compressed Natural Gas） powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.
