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
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
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
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
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
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
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
This paper presents the development of an urban river water quality model which considers the physical-biochemical processes within rivers and the incorporated urban catchment rainfall-runoff process developed with th...This paper presents the development of an urban river water quality model which considers the physical-biochemical processes within rivers and the incorporated urban catchment rainfall-runoff process developed with the time-area method. Unlike other models that simulate the hydrological and receiving water quality processes in the rural areas of the watershed scale, the model developed here is typically efficient for simulating the water quality response to nonpoint loadings from urban drainage systems, where the hydrological process is disturbed by artificially pumped discharge in wet-weather periods. This model is employed to assess the river water quality restoration in Nanfei River in Hefei City, China, where the model is calibrated against the measured data(i.e., the COD, the BOD5, the NH3-N, and the DO) in 2010, and the model parameters are suggested. It is shown that the nonpoint pollutants from the urban catchments contribute 34%-47% of the total pollutant inputs(i.e., the COD, the BOD5, and the NH3-N), despite their low flow component of 13.4%. Apart from the improvement of the wastewater treatment plant effluent(i.e., Grade IV of the Surface Water Quality Standard), a nonpoint loading reduction of 27.2%, 25.1%, and 35.3% of the COD, the BOD5, and the NH3-N are anticipated to meet the designated surface water quality standards of Grade V.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
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
Increasing Chinese urbanization and industrialization has prompted greater attention to the study of human settlement and the human-land relationship in the fields of geography, architecture, and urban planning. We us...Increasing Chinese urbanization and industrialization has prompted greater attention to the study of human settlement and the human-land relationship in the fields of geography, architecture, and urban planning. We used bibliometric methods and statistical software to review 180 articles on human settlement in 16 Chinese geographical journals. We found that Chinese geographical human settlement research is characterized by the following:(1) Most research focuses on human settlement extension, valuation indicators, models for urban and rural settlements, theoretical exploration and the planning practices of single-factor, human settlement and complex, geographical livability in macro-scale, urban settlement differentiation and ideal patterns in medium scale, the comprehensive evaluation of settlement environment, and the planning of community units in micro-scale, community settlements; socio-cultural investigation and warnings about advancing human settlement.(2) No progress has been made in synthesizing and integrating method systems. PSR models and DPSIR models are used for targeting mechanisms, while the standard settlement evaluation system was composed of physical & economic indicators by questionnaire surveys. On the other hand, spatial clustering based on GIS has been a frequent focus in recent years. Pioneering research on human settlement and theoretical systems within the context of China's urbanization and industrialization will provide guidance on the sustainability of Chinese cities and regions. The following five aspects require greater attention:(1) Natural suitability research on human settlement, and a survey of human settlement demands to reflect the range of different demands concerning ecologically suitable settlements in urban environments, the corresponding valuation indicators, systems, and evolution, and the impact of the residents' socio-economic attributes.(2) Spatial-temporal evaluation and sustainability research on urban and rural human settlement at various scales, focusing on evolution and spatial differen-tiation at various scales such as city clusters and comparisons between cities, within the cities and communities.(3) Development of theory and technology for human settlement evolution research, including detection technology and methods, data mining measures, and forecasting and emulation of regional and urban human settlement evolution processes, mechanisms and patterns.(4) Research on the control of human settlement that focuses on optimization, patterns, and policies for effective management and development.(5) Estimating the human settlement system service value and establishing suitable human settlement systems, including social, economic, cultural and ecological service values.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.
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.
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.
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
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.
基金Project supported by the Major Science and Technology Program for Water Pollution Control and Treatment(Grant Nos.2011ZX07303-002,2013ZX07304-002)the Shanghai Science and Technology Commission(Grant No.13DZ2251700)
文摘This paper presents the development of an urban river water quality model which considers the physical-biochemical processes within rivers and the incorporated urban catchment rainfall-runoff process developed with the time-area method. Unlike other models that simulate the hydrological and receiving water quality processes in the rural areas of the watershed scale, the model developed here is typically efficient for simulating the water quality response to nonpoint loadings from urban drainage systems, where the hydrological process is disturbed by artificially pumped discharge in wet-weather periods. This model is employed to assess the river water quality restoration in Nanfei River in Hefei City, China, where the model is calibrated against the measured data(i.e., the COD, the BOD5, the NH3-N, and the DO) in 2010, and the model parameters are suggested. It is shown that the nonpoint pollutants from the urban catchments contribute 34%-47% of the total pollutant inputs(i.e., the COD, the BOD5, and the NH3-N), despite their low flow component of 13.4%. Apart from the improvement of the wastewater treatment plant effluent(i.e., Grade IV of the Surface Water Quality Standard), a nonpoint loading reduction of 27.2%, 25.1%, and 35.3% of the COD, the BOD5, and the NH3-N are anticipated to meet the designated surface water quality standards of Grade V.
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.41230632,No.41301110,No.41501119 Zhejiang Provincial Natural Science Foundation of China,No.LY16D010008,No.Y14D010007
文摘Increasing Chinese urbanization and industrialization has prompted greater attention to the study of human settlement and the human-land relationship in the fields of geography, architecture, and urban planning. We used bibliometric methods and statistical software to review 180 articles on human settlement in 16 Chinese geographical journals. We found that Chinese geographical human settlement research is characterized by the following:(1) Most research focuses on human settlement extension, valuation indicators, models for urban and rural settlements, theoretical exploration and the planning practices of single-factor, human settlement and complex, geographical livability in macro-scale, urban settlement differentiation and ideal patterns in medium scale, the comprehensive evaluation of settlement environment, and the planning of community units in micro-scale, community settlements; socio-cultural investigation and warnings about advancing human settlement.(2) No progress has been made in synthesizing and integrating method systems. PSR models and DPSIR models are used for targeting mechanisms, while the standard settlement evaluation system was composed of physical & economic indicators by questionnaire surveys. On the other hand, spatial clustering based on GIS has been a frequent focus in recent years. Pioneering research on human settlement and theoretical systems within the context of China's urbanization and industrialization will provide guidance on the sustainability of Chinese cities and regions. The following five aspects require greater attention:(1) Natural suitability research on human settlement, and a survey of human settlement demands to reflect the range of different demands concerning ecologically suitable settlements in urban environments, the corresponding valuation indicators, systems, and evolution, and the impact of the residents' socio-economic attributes.(2) Spatial-temporal evaluation and sustainability research on urban and rural human settlement at various scales, focusing on evolution and spatial differen-tiation at various scales such as city clusters and comparisons between cities, within the cities and communities.(3) Development of theory and technology for human settlement evolution research, including detection technology and methods, data mining measures, and forecasting and emulation of regional and urban human settlement evolution processes, mechanisms and patterns.(4) Research on the control of human settlement that focuses on optimization, patterns, and policies for effective management and development.(5) Estimating the human settlement system service value and establishing suitable human settlement systems, including social, economic, cultural and ecological service values.
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.