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Deducing Leading Factors of Spatial Distribution of Carbon Reserves in Nanjing Metropolitan Area Based on Random Forest Model. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2022; 2022:3013620. [PMID: 36059423 PMCID: PMC9436533 DOI: 10.1155/2022/3013620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022]
Abstract
Improving carbon reserves is considered to be an important way to alleviate global warming. However, there is a lack of research work based on the perspective of metropolitan area, and there is also a lack of analysis on the leading influencing factors of spatial distribution of carbon storage in subregions of metropolitan area. In this study, Nanjing metropolitan area (NMA) is taken as the research area, and the InVEST model is used to calculate the spatial distribution of regional carbon reserves, and the evolution of carbon reserves distribution in recent 20 years is analyzed. Then, based on the random forest (RF) model, taking the whole study area and subareas as the research scope, a regression model of each selected impact factor and carbon reserves is established, and the leading factors of spatial distribution of carbon reserves in NMA are obtained. The results show that the overall carbon reserves level in the study area is in a downward trend. Through the application of the RF model, the leading factors of the spatial distribution of carbon reserves in NMA and its subareas are derived. The research proves that the application of the RF model in the analysis is helpful for city planners and governments to make plans and improve regional carbon storage more effectively.
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Chen C, Zhang H, Yan W, Wu N, Zhang Q, He K. Aerosol water content enhancement leads to changes in the major formation mechanisms of nitrate and secondary organic aerosols in winter over the North China Plain. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 287:117625. [PMID: 34186500 DOI: 10.1016/j.envpol.2021.117625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 06/12/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
In recent years, severe air pollution still frequently occurs in winter despite the effective implementation of clean air actions in China. Therefore, field measurements of particle composition and gas precursors were collected from December 1, 2018 to January 15, 2019 at an urban site in a central Chinese city to investigate the existing mechanisms of pollution. The hourly averaged PM2.5 concentration during the campaign was 92.7 μg m-3, with nitrate and organic aerosol (OA) demonstrated as the principal components. Generally, NO2 oxidation in the daytime was observed as the major mechanism for nitrate generation, and aerosol water content (AWC) showed its influential role with the associated increases in the nitrogen oxidation and nitrate partitioning ratios. When AWC increased from dozens to hundreds of μg m-3 after the afternoon, nocturnal N2O5 hydrolysis was demonstrated as the overriding mechanism and provoked extreme contamination of nitrates. Five sources of organic aerosols (OAs) were identified: hydrocarbon-like OAs (HOAs, 16.5%), coal combustion OAs (CCOAs, 19.2%), biomass burning OAs (BBOAs, 9.9%), semi-volatile oxygenated OAs (SV-OOAs, 29.4%), and low-volatile oxygenated OAs (LV-OOAs, 25.0%). SV-OOAs and LV-OOAs were identified as gasSOAs and aqSOAs according to their sensitivities to the atmospheric oxidation capacity and AWC. In addition, aqueous-phase processing was found to be the dominant pathway for SOA formation when the AWC concentration was higher than 80 μg m-3. As an influential factor for nitrate and SOA formation, AWC could be greatly affected by RH and the concentrations of inorganic species. Sulfate, which was mainly contributed by anthropogenic emissions, was demonstrated to be a significant factor for active aqueous phase reactions, although SO2 has been dramatically reduced in recent years. Above all, this study revealed the significant role of AWC in current pollution episode in winter, and will assist in establishing future measures for pollution mitigation.
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Affiliation(s)
- Chunrong Chen
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Haixu Zhang
- School of Environment, Tsinghua University, Beijing, 100084, China.
| | - Weijia Yan
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Nana Wu
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Qiang Zhang
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Kebin He
- School of Environment, Tsinghua University, Beijing, 100084, China
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Wang G, Zhu Z, Zhao N, Wei P, Li G, Zhang H. Variations in characteristics and transport pathways of PM 2.5 during heavy pollution episodes in 2013-2019 in Jinan, a central city in the north China Plain. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117450. [PMID: 34049162 DOI: 10.1016/j.envpol.2021.117450] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 05/24/2023]
Abstract
The characteristics and transport pathways of air masses vary during heavy pollution episodes (HPEs). Three categories of HPEs have been defined: HPE Ι, II, and III, corresponding to HPE durations of 1, 2, and at least 3 days, respectively. Sixty HPEs were investigated in this study. The number of HPEs decreased from 2013 to 2017 and then increased from 2017 to 2019, dominated by emission reductions and meteorological conditions. The average and maximum PM2.5 (i.e., aerodynamic diameter of <2.5 μm) concentrations during those HPEs in 2019 decreased by 5.6%-11.8% and 11.9%-38.5%, respectively, compared with those in 2013. The longer the duration of an HPE, the higher the PM2.5 concentration. Secondary inorganic aerosol concentrations and their contents in PM2.5 during HPE Ⅲ were found to be higher than those during HPEs Ι and Ⅱ, as secondary transformations of precursor gases are more intense during long-term HPEs. The dominant trajectories of airflow arriving in Jinan originated from the southern and southeastern regions during HPEs, realized using the Hybrid Single Particle Lagrangian Integrated Trajectory. The trajectories from the north and west of Jinan contained the highest PM2.5 concentrations of 323.3-432.1 μg/m3 during HPE Ⅲ, although these trajectories only contributed 5.6%-11.1% of the total dominant transport pathways, while those in trajectories from the northwest were highest during HPEs Ι and Ⅱ. The highest contributions of air masses from short distances were found during HPE Ⅲ, of 77.8%, while they were only 65.6% and 47.8% during HPEs Ι and II, respectively. More attention should be given to transport pathways within the short distance from Jinan. Therefore, enhancing regional cooperation in Jinan and surrounding regions (particularly in the south, southeast, northwest, west, and north) is critical for improving air quality in the North China Plain.
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Affiliation(s)
- Gang Wang
- Department of Environmental and Safety Engineering, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
| | - Zhongyi Zhu
- Department of Environmental and Safety Engineering, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Na Zhao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai, 200433, China
| | - Peng Wei
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Guohao Li
- Municipal Research Institute of Environmental Protection, Beijing, 100037, China; Key Laboratory of Beijing on VOC Pollution Control Technology and Application of Urban Atmosphere, Beijing, 100037, China
| | - Hanyu Zhang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China
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Wang T, Wang H, Chen J, Wang J, Ren D, Hu W, Wang H, Han W, Leng S, Zhang R, Zheng Y. Association between air pollution and lung development in schoolchildren in China. J Epidemiol Community Health 2020; 74:792-798. [PMID: 32527860 PMCID: PMC7577101 DOI: 10.1136/jech-2020-214283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/13/2020] [Accepted: 05/23/2020] [Indexed: 12/24/2022]
Abstract
Background China has been facing nationwide air pollution at unprecedented high levels primarily from fossil–fuel combustion in the past decade. However, few studies have been conducted on the adverse effect of severe air pollution on lung development in school-age children. Methods Using wellness check and air pollution data from 2014 to 2017, we conducted a retrospective analysis of lung development in 21 616 school-age children from Shijiazhuang and Qingdao from North China with severe vs mild air pollution. Linear mixed effects model was performed to assess the effect of air pollution on forced vital capacity (FVC) growth. Results Exposure to severe air pollution was associated with a dramatic reduction in annual FVC growth rate (−71.3 mL, p< 0.001). In addition, every 10 μg/m3 increase in annual PM2.5 level was associated with a reduction of annual FVC growth by 12.2 mL ( p< 0.001). Sex discrepancy (boys vs girls) in FVC growth was greater in Qingdao (35.4 mL/year, 95% CI: 26.0 to 44.7) than in Shijiazhuang (19.8 mL/year, 95% CI: 9.3 to 30.3) (p for interaction=0.063). Exposure to indoor coal- or wood-burning stove heating (−79.4 mL, p< 0.001) and secondhand smoke at home (−59.3 mL, p= 0.003) were inversely associated with FVC growth. Conclusion Our study raised serious alarm over the threat of severe air pollution to lung development in school-age children. Sex discrepancy in lung development was reduced dramatically in heavily polluted area.
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Affiliation(s)
- Tao Wang
- Department of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Haitao Wang
- Department of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Jian Chen
- Department of School Health, Qingdao Municipal Center for Disease Control and Prevention, Qingdao, China
| | - Jiansheng Wang
- Policy Research Center for Environment and Economy, Ministry of Ecology and Environment of the People's Republic of China, Beijing, China
| | - Dunqiang Ren
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Wei Hu
- Department of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Hongmei Wang
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Wei Han
- Department of Respiratory and Critical Care Medicine, Qingdao Municipal Hospital Group, Qingdao, China
| | - Shuguang Leng
- Department of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Rong Zhang
- Department of Toxicology, School of Public Health, Hebei Medical University, Shijiazhuang City, China
| | - Yuxin Zheng
- Department of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
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Research Progress of HP Characteristics, Hazards, Control Technologies, and Measures in China after 2013. ATMOSPHERE 2019. [DOI: 10.3390/atmos10120767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In recent years, hazy weather (hazy weather (HW) has frequently invaded peoples’ lives in China, resulting in the disturbance of social operation, so it is urgent to resolve the haze pollution (HP) problem. A comprehensive understanding of HP is essential to further effectively alleviate or even eliminate it. In this study, HP characteristics in China, after 2013, were presented. It was found that the situation of HP is getting better year by year while it has been a pattern of high levels in the north and low levels in the south. In most regions of China, the contribution of a secondary source for HP is relatively large, and that of traffic is greater in the regions with rapid economic development. Hazards of HP were then summarized. Not only does HP cause harm to human health, but it also has effects on human production and quality of life, furthermore, property and atmospheric environment cannot be ignored. Next, the source and non-source control technologies of HP were first reviewed to recognize the weakness of HP control in China. This review provides more systematic information about HP problems and the future development directions of HP research were proposed to further effectively control HP in China.
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Analysis of the Air Quality and the Effect of Governance Policies in China’s Pearl River Delta, 2015–2018. ATMOSPHERE 2019. [DOI: 10.3390/atmos10070412] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The evaluation of China’s air pollution and the effectiveness of its governance policies is currently a topic of general concern in the academic community. We have improved the traditional evaluation method to construct a comprehensive air quality assessment model based on China’s major air pollutants. Using the daily air pollutant data of 2015–2018, we calculated and analyzed the monthly air quality of nine cities in the Pearl River Delta of China, and conducted a comparative study on the effect of the air pollution control policies of the cities in the Pearl River Delta. We found that the air quality control policies in those nine cities were not consistent. Specifically, the pollution control policies of Guangzhou and Foshan have achieved more than 20% improvement. The pollution control policies of Dongguan and Zhaoqing have also achieved more than 10% improvement. However, due to the relative lag of the formulation and implementation of air pollution control policies, the air quality of Jiangmen, Zhuhai and Zhongshan has declined. Based on the analysis of the air quality assessment results and the effects of governance policies in each city during the study period, we propose suggestions for further improvement of the effectiveness of air pollution control policies in the region.
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Abstract
A heavy rainstorm occurred in Beijing on 19–20 July 2016. The Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem) was used to investigate the effects of anthropogenic aerosols on precipitation and microphysical processes. Three conditions were simulated by altering the anthropogenic emissions. When the anthropogenic emissions were increased by 10 times, the area-average accumulated rainfall amount and maximum accumulated rainfall amount both decreased. The cloud water mixing ratio increased and the rain mixing ratio decreased. The radii of cloud droplets decreased, and the collision efficiency of cloud water by rain and the autoconversion rate of cloud water into rain were both low. When the anthropogenic emission was 10% of the original emission, the area of accumulated rainfall amounts greater than 25 mm in the Beijing area was 10% larger than those of the other two tests. The collision efficiency and autoconversion rate of cloud water into rain were high for large contact areas and large cloud droplets. The graupel mixing ratio was the largest. Thus, the process of melting of graupel into rain was the largest. In the WRF-Chem model, the aerosols did not participate as ice nuclei (IN) in the ice-phase microphysical processes, and therefore the aerosols could influence only the warm rain processes and mix-phased processes near the freezing level line. For no influence on ice-phase microphysical processes, the snow and ice mixing ratios did not show many differences among the different tests.
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