scholarly journals The impact of traffic isolation in Wuhan on the spread of 2019-nCov

2020 ◽  
Author(s):  
Gehui Jin ◽  
Jiayu Yu ◽  
Liyuan Han ◽  
Shiwei Duan
Keyword(s):  
Mortality Rate ◽  
Chinese Spring ◽  
Mainland China ◽  
Hubei Province ◽  
Migrant Population ◽  
Migration Index ◽  
Spring Festival ◽  
The Impact

The 2019-nCoV outbreak occurred near the Chinese Spring Festival transport period in Wuhan. As an important transportation center, the migration of Wuhan accelerated the spread of 2019-nCoV across mainland China. Based on the cumulative Baidu migration index (CBMI), we first analyzed the proportion of Wuhan’s migrant population to other cities. Our results confirm that there is a significant correlation between the export population of Wuhan and reported cases in various regions. We subsequently found that the mortality rate in Hubei Province was much higher than that in other regions of mainland China, while the investigation of potential cases in Wuhan was far behind other provinces in Mainland China, which indicates the effectiveness of early isolation.

scholarly journals Interactions between Bus, Metro, and Taxi Use before and after the Chinese Spring Festival

2019 ◽  
Vol 8 (10) ◽  
pp. 445 ◽  
Author(s):  
Jianwei Huang ◽  
Xintao Liu ◽  
Pengxiang Zhao ◽  
Junwei Zhang ◽  
Mei-Po Kwan
Keyword(s):  
Built Environment ◽  
Chinese Spring ◽  
Small Scale ◽  
Demographic Changes ◽  
Interaction Patterns ◽  
Trajectory Data ◽  
Transport Services ◽  
Spring Festival ◽  
Before And After ◽  
The Impact

Public transport plays an important role in developing sustainable cities. A better understanding of how different public transit modes (bus, metro, and taxi) interact with each other will provide better sustainable strategies to transport and urban planners. However, most existing studies are either limited to small-scale surveys or focused on the identification of general interaction patterns during times of regular traffic. Transient demographic changes in a city (i.e., many people moving out and in) can lead to significant changes in such interaction patterns and provide a useful context for better investigating the changes in these patterns. Despite that, little has been done to explore how such interaction patterns change and how they are linked to the built environment from the perspective of transient demographic changes using urban big data. In this paper, the tap-in-tap-out smart card data of bus/metro and taxi GPS trajectory data before and after the Chinese Spring Festival in Shenzhen, China, are used to explore such interaction patterns. A time-series clustering method and an elasticity change index (ECI) are adopted to detect the changing transit mode patterns and the underlying dynamics. The findings indicate that the interactions between different transit modes vary over space and time and are competitive or complementary in different parts of the city. Both ordinary least-squares (OLS) and geographically weighted regression (GWR) models with built environment variables are used to reveal the impact of changes in different transit modes on ECIs and their linkage with the built environment. The results of this study will contribute to the planning and design of multi-modal transport services.

scholarly journals Aerosol composition and sources during the Chinese Spring Festival: fireworks, secondary aerosol, and holiday effects

2015 ◽  
Vol 15 (11) ◽  
pp. 6023-6034 ◽  
Author(s):  
Q. Jiang ◽  
Y. L. Sun ◽  
Z. Wang ◽  
Y. Yin
Keyword(s):  
Chinese Spring ◽  
Fine Particles ◽  
Nitrogen Monoxide ◽  
Primary Source ◽  
Organic Aerosol ◽  
Aerosol Composition ◽  
Secondary Aerosol ◽  
Particulate Pollution ◽  
Spring Festival ◽  
The Impact

Abstract. Aerosol particles were characterized by an Aerodyne aerosol chemical speciation monitor along with various collocated instruments in Beijing, China, to investigate the role of fireworks (FW) and secondary aerosol in particulate pollution during the Chinese Spring Festival of 2013. Three FW events, exerting significant and short-term impacts on fine particles (PM2.5), were observed on the days of Lunar New Year, Lunar Fifth Day, and Lantern Festival. The FW were shown to have a large impact on non-refractory potassium, chloride, sulfate, and organics in submicron aerosol (PM1), of which FW organics appeared to be emitted mainly in secondary, with its mass spectrum resembling that of secondary organic aerosol (SOA). Pollution events (PEs) and clean periods (CPs) alternated routinely throughout the study. Secondary particulate matter (SPM = SOA + sulfate + nitrate + ammonium) dominated the total PM1 mass on average, accounting for 63–82% during nine PEs in this study. The elevated contributions of secondary species during PEs resulted in a higher mass extinction efficiency of PM1 (6.4 m2 g-1) than during CPs (4.4 m2 g-1). The Chinese Spring Festival also provides a unique opportunity to study the impact of reduced anthropogenic emissions on aerosol chemistry in the city. Primary species showed ubiquitous reductions during the holiday period with the largest reduction being in cooking organic aerosol (OA; 69%), in nitrogen monoxide (54%), and in coal combustion OA (28%). Secondary sulfate, however, remained only slightly changed, and the SOA and the total PM2.5 even slightly increased. Our results have significant implications for controlling local primary source emissions during PEs, e.g., cooking and traffic activities. Controlling these factors might have a limited effect on improving air quality in the megacity of Beijing, due to the dominance of SPM from regional transport in aerosol particle composition.

scholarly journals Impact of anthropogenic emission on air quality over a megacity – revealed from an intensive atmospheric campaign during the Chinese Spring Festival

2012 ◽  
Vol 12 (23) ◽  
pp. 11631-11645 ◽  
Author(s):  
K. Huang ◽  
G. Zhuang ◽  
Y. Lin ◽  
Q. Wang ◽  
J. S. Fu ◽  
...  
Keyword(s):  
Air Quality ◽  
Human Activity ◽  
Public Transportation ◽  
Chinese Spring ◽  
Dominant Role ◽  
Organic Aerosol ◽  
Light Extinction ◽  
Vehicular Emissions ◽  
Spring Festival ◽  
The Impact

Abstract. The Chinese Spring Festival is one of the most important traditional festivals in China. The peak transport in the Spring Festival season (spring travel rush) provides a unique opportunity for investigating the impact of human activity on air quality in the Chinese megacities. Emission sources are varied and fluctuate greatly before, during and after the Festival. Increased vehicular emissions during the "spring travel rush" before the 2009 Festival resulted in high level pollutants of NOx (270 μg m−3), CO (2572 μg m−3), black carbon (BC) (8.5 μg m−3) and extremely low single scattering albedo of 0.76 in Shanghai, indicating strong, fresh combustion. Organics contributed most to PM2.5, followed by NO3−, NH4+, and SO42−. During the Chinese Lunar New Year's Eve and Day, widespread usage of fireworks caused heavy pollution of extremely high aerosol concentration, scattering coefficient, SO2, and NOx. Due to the "spring travel rush" after the festival, anthropogenic emissions gradually climbed and mirrored corresponding increases in the aerosol components and gaseous pollutants. Secondary inorganic aerosol (SO42−, NO3−, and NH4+) accounted for a dominant fraction of 74% in PM2.5 due to an increase in human activity. There was a greater demand for energy as vast numbers of people using public transportation or driving their own vehicles returned home after the Festival. Factories and constructions sites were operating again. The potential source contribution function (PSCF) analysis illustrated the possible source areas for air pollutants of Shanghai. The effects of regional and long-range transport were both revealed. Five major sources, i.e. natural sources, vehicular emissions, burning of fireworks, industrial and metallurgical emissions, and coal burning were identified using the principle component analysis. The average visibility during the whole study period was less than 6 km. It had been estimated that 50% of the total light extinction was due to the high water vapor in the atmosphere. This study demonstrates that organic aerosol was the largest contributor to aerosol extinction at 47%, followed by sulfate ammonium, nitrate ammonium, and EC at 22%, 14%, and 12%, respectively. Our results indicated the dominant role of traffic-related aerosol species (i.e. organic aerosol, nitrate and EC) on the formation of air pollution, and suggested the importance of controlling vehicle numbers and emissions in mega-cities of China as its population and economy continue to grow.

scholarly journals The impacts of firework burning at the Chinese Spring Festival on air quality: insights of tracers, source evolution and aging processes

2015 ◽  
Vol 15 (4) ◽  
pp. 2167-2184 ◽  
Author(s):  
S. F. Kong ◽  
L. Li ◽  
X. X. Li ◽  
Y. Yin ◽  
K. Chen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Air Quality ◽  
Human Health ◽  
Chinese Spring ◽  
Soot Formation ◽  
Water Soluble ◽  
Chemical Compositions ◽  
Spring Festival ◽  
Haze Pollution ◽  
The Impact

Abstract. To understand the impact of firework-burning (FW) particles on air quality and human health during the winter haze period, 39 elements, 10 water-soluble ions and 8 fractions of carbonaceous species in atmospheric PM2.5 in Nanjing were investigated during the 2014 Chinese Spring Festival (SF). Serious regional haze pollution persisted throughout the entire sampling period, with PM2.5 averaging at 113 ± 69 μg m−3 and visibility at 4.8 ± 3.2 km. The holiday effect led to almost all the chemical species decreasing during the SF, except for Al, K, Ba and Sr which were related to FW. The source contributions of coal combustion, vehicle emission and road dust decreased dramatically, whereas FW contributed to about half of the PM2.5 during the SF period. The intensive emission of FW particles on New Year's Eve accounted for 60.1% of the PM2.5. Fireworks also obviously modified the chemical compositions of PM2.5, with 39.3% contributed by increased organic matter, followed by steadily increased loadings of secondary inorganic ions. The aging processes of the FW particles lasted for about 4 days reflected by the variations of Ba, Sr, NH4+, NO3−, SO42− and K+, characterized by heterogeneous reactions of SO2 and NOx on crustal materials directly from FW, the replacement of Cl− by NO3− and SO42−, coating of NO3− and SO42− on soot, formation of secondary organic aerosols and metal-catalyzed formation of NO3− and SO42− at higher relative humidity. During aging, the main contributors to the extinction coefficient shifted from elemental carbon and organic matter to ammonium sulfate. The particles raised higher cancer risk of 1.62 × 10−6 by heavy metals (especially for Cd and As). This study provided detailed composition data and first comprehensive analysis of the aging processes of FW particles during the serious haze pollution period and their potential impact on human health.

scholarly journals Changing transmission dynamics of COVID-19 in China: a nationwide population-based piecewise mathematical modelling study

2020 ◽  
Author(s):  
Jiawen Hou ◽  
Jie Hong ◽  
Boyun Ji ◽  
Bowen Dong ◽  
Yue Chen ◽  
...  
Keyword(s):  
Mathematical Modelling ◽  
Reproduction Number ◽  
Mainland China ◽  
Hubei Province ◽  
Transmission Dynamics ◽  
Population Movement ◽  
Long Distance ◽  
Spring Festival ◽  
Travel Restrictions ◽  
Controlled Reproduction

AbstractBackgroundThe first case of COVID-19 atypical pneumonia was reported in Wuhan, China on December 1, 2019. Since then, at least 33 other countries have been affected and there is a possibility of a global outbreak. A tremendous amount of effort has been made to understand its transmission dynamics; however, the temporal and spatial transmission heterogeneity and changing epidemiology have been mostly ignored. The epidemic mechanism of COVID-19 remains largely unclear.MethodsEpidemiological data on COVID-19 in China and daily population movement data from Wuhan to other cities were obtained and analyzed. To describe the transmission dynamics of COVID-19 at different spatio-temporal scales, we used a three-stage continuous-time Susceptible-Exposed-Infectious-Recovered (SEIR) meta-population model based on the characteristics and transmission dynamics of each stage: 1) local epidemic from December 1, 2019 to January 9, 2020; 2) long-distance spread due to the Spring Festival travel rush from January 10 to 22, 2020; and 3) intra-provincial transmission from January 23, 2020 when travel restrictions were imposed. Together with the basic reproduction number (R0) for mathematical modelling, we also considered the variation in infectivity and introduced the controlled reproduction number (Rc) by assuming that exposed individuals to be infectious; we then simulated the future spread of COVID across Wuhan and all the provinces in mainland China. In addition, we built a novel source tracing algorithm to infer the initial exposed number of individuals in Wuhan on January 10, 2020, to estimate the number of infections early during this epidemic.FindingsThe spatial patterns of disease spread were heterogeneous. The estimated controlled reproduction number (Rc) in the neighboring provinces of Hubei province were relatively large, and the nationwide reproduction number ‐ except for Hubei ‐ ranged from 0.98 to 2.74 with an average of 1.79 (95% CI 1.77‐1.80). Infectivity was significantly greater for exposed than infectious individuals, and exposed individuals were predicted to have become the major source of infection after January 23. For the epidemic process, most provinces reached their epidemic peak before February 10, 2020. It is expected that the maximum number of infections will be approached by the end of March. The final infectious size is estimated to be about 58,000 for Wuhan, 20,800 for the rest of Hubei province, and 17,000 for the other provinces in mainland China. Moreover, the estimated number of the exposed individuals is much greater than the officially reported number of infectious individuals in Wuhan on January 10, 2020.InterpretationThe transmission dynamics of COVID-19 have been changing over time and were heterogeneous across regions. There was a substantial underestimation of the number of exposed individuals in Wuhan early in the epidemic, and the Spring Festival travel rush played an important role in enhancing and accelerating the spread of COVID-19. However, China’s unprecedented large-scale travel restrictions quickly reduced Rc. The next challenge for the control of COVID-19 will be the second great population movement brought by removing these travel restrictions.

scholarly journals The impacts of fireworks burning at Chinese Spring Festival on air quality and human health: insights of tracers, source evolution and aging processes

2014 ◽  
Vol 14 (21) ◽  
pp. 28609-28655 ◽  
Author(s):  
S. Kong ◽  
L. Li ◽  
X. Li ◽  
Y. Yin ◽  
K. Chen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Air Quality ◽  
Human Health ◽  
Chinese Spring ◽  
Soot Formation ◽  
Water Soluble ◽  
Chemical Compositions ◽  
Spring Festival ◽  
Haze Pollution ◽  
The Impact

Abstract. To understand the impact of fireworks burning (FW) particles on air quality and human health during winter haze period, thirty-nine elements, ten water-soluble ions and eight fractions of carbonaceous species in atmospheric PM2.5 at Nanjing were investigated during 2014 Chinese Spring Festival (SF). Serious regional haze pollution persisted throughout the entire sampling period, PM2.5 averaging at 113 ± 69 μg m−3 and visibility at 4.8 ± 3.2 km. The holiday effect led to almost all the chemical species decreasing during the SF, except for Al, K, Ba and Sr which were related to FW. The source contributions of coal combustion, vehicle emission and road dust descreased dramatically, whereas FW contributed to about half of the PM2.5 during SF period. The intensive emission of FW particles at New Year's Eve accounted for 60.1% of the PM2.5. They also significnatly modified the chemical compositions of PM2.5, with 39.3% contributed by increased organic matter, followed by steadly increased loadings of secondary inorganic ions. The aging processes of the FW particles lasted for at least six days reflected by the variation of SO42−, characterized by heterogeneous reactions of SO2 and NOx on crustal materials directly from FW, the replacement of Cl− by NO3− and SO42− coating of NO3− and SO42− on soot, formation of secondary organic aerosols and metal-catalyzed formation of NO3− and SO42− at higher relative humidity. During aging, the main contributors to the extinction coefficient shifted from elemental carbon and organic matter to sulfate ammonium. The particles raised higher cancer risks by heavy metals (especially for Cd and As) as 1.62 ×10−6. This study provided detailed composition data and first comprehensive analysis of the aging processes of FW particles at serious haze pollution period and their potential impact on human health.

scholarly journals Reductions of Migrant Population Reduces the Number of COVID-19 Epidemic: A Case Study in China

2020 ◽  
Author(s):  
Lizhen Han ◽  
Jinzhu Jia
Keyword(s):  
Population Density ◽  
Generalized Additive Model ◽  
Hot Spot ◽  
Additive Model ◽  
Hubei Province ◽  
Control Measures ◽  
Cumulative Number ◽  
Migrant Population ◽  
High Prevalence ◽  
The Impact

Abstract Background: The novel coronavirus disease (COVID-19) broke out worldwide in 2020. The purpose of this paper was to find out the impact of migrant population on the epidemic, aiming to provide data support and suggestions for control measures in various epidemic areas. Methods: Generalized additive model was utilized to model the relationship between migrant population and the cumulative number of confirmed cases of COVID-19. The difference of spatial distribution was analyzed through spatial autocorrelation and hot spot analysis. Results: Generalized additive model demonstrated that the cumulative number of confirmed cases was positively correlated with migration index and population density. The predictive results showed that if no travel restrictions are imposed on the migrant population as usual, the total cumulative number of confirmed cases of COVID-19 would have reached 27 483 (95% CI: 16 074, 48 097; the actual number was 23 177). The increase in one city (Jian) would be 577.23% (95% CI: 322.73%, 972.73%) compared to the real confirmed cases of COVID-19. The average increase in 73 cities was 85.53% (95% CI: 19.53%, 189.81%). Among the migration destinations, the number of cases in cities of Hubei province, Chongqing and Beijing was relatively high, and there were large-scale high-prevalence clusters in eastern Hubei province. Meanwhile, without restrictions on migration, the high prevalence areas in Hubei province and its surrounding areas will be further expanded. Conclusions: The reduced population mobility and population density can greatly slow down the spread of the epidemic. All epidemic areas should suspend the transportation between cities, comprehensively and strictly control the population travel and decrease the population density, so as to reduce the spread of COVID-19.

scholarly journals Should internal migrants be held accountable for spreading COVID-19?

2020 ◽  
Vol 52 (4) ◽  
pp. 695-697 ◽  
Author(s):  
Qiujie Shi ◽  
Tao Liu
Keyword(s):  
Internal Migration ◽  
Chinese Spring ◽  
Large Scale ◽  
Hubei Province ◽  
Major Contributor ◽  
Job Seekers ◽  
Business People ◽  
Spring Festival ◽  
Internal Migrants ◽  
Novel Coronavirus

The 2019 novel coronavirus disease (COVID-19) has quickly swept through China, and mass internal migration during the Chinese Spring Festival is now widely blamed for this. This statement, we argue, is misleading. Internal migrants should not be held responsible for the initial spread of COVID-19, as those cities first affected are megacities that connect with the epicentre Wuhan more with regard to business and tourism than migration. The scale of the epidemic can only be partially explained by internal migration. Severe outbreaks are not limited to cities that neighbour Hubei Province and that have large migration to Wuhan. They also occurred in provincial capitals that are neither contiguous with Hubei nor connected with Wuhan in terms of migration. Even though a few cities far away from the epicentre were hit severely by COVID-19 due to migration, the major contributor is not the migrant job seekers but business people. The responsibility of spreading COVD-19 so fast, on such a large scale and so far is by no means fully on internal migrants.

scholarly journals Impact of anthropogenic emission on air-quality over a megacity – revealed from an intensive atmospheric campaign during the Chinese Spring Festival

2012 ◽  
Vol 12 (7) ◽  
pp. 17151-17185 ◽  
Author(s):  
K. Huang ◽  
G. Zhuang ◽  
Y. Lin ◽  
Q. Wang ◽  
J. S. Fu ◽  
...  
Keyword(s):  
Air Quality ◽  
Public Transportation ◽  
Human Activities ◽  
Chinese Spring ◽  
Organic Aerosol ◽  
Light Extinction ◽  
Anthropogenic Emission ◽  
Aerosol Mass Concentration ◽  
Spring Festival ◽  
The Impact

Abstract. The Chinese Spring Festival is one of the most important traditional festivals in China. The peak transport in the Spring Festival season (spring travel rush) provides a unique opportunity for investigating the impact of human activities on air quality in the Chinese megacities as emission sources varied and fluctuated greatly prior to, during and after the festival. Enhanced vehicular emission during the spring travel rush before the festival resulted in high level pollutants of NOx (270 μg m−3), CO (2572 μg m−3), BC (8.5 μg m−3) and extremely low single scattering albedo of 0.70, indicating strong fresh combustion. Organics contributed most to PM2.5, followed by NO3−, NH4+, and SO42−. During the Chinese Lunar New Year's Eve and Day, widespread usage of fireworks burning caused heavy pollution of extremely high aerosol mass concentration, scattering coefficient, SO2 and NOx. Due to the spring travel rush after the festival, anthropogenic emission gradually climbed and mirrored corresponding increases in the aerosol components and gaseous pollutants. Secondary inorganic aerosol (SO42−, NO3−, and NH4+) accounted for a dominant fraction of 74% in PM2.5 due to the enhanced human activities, e.g. higher demand of energy usage from returned residents and re-open of factories and construction sites, more vehicle mileages due to returned workers and expanded public transportation. The average visibility during whole study period was less than 6 km. It was estimated that about 50% of the total light extinction was due to the high water vapor in the atmosphere. Of the aerosol extinction, organic aerosol had the largest contribution of 47%, followed by sulfate ammonium, nitrate ammonium and EC of 22%, 14%, and 12%, respectively. Our results indicated the dominant role of traffic-related aerosol species (i.e. organic aerosol, nitrate and EC) on the formation of air pollution, and suggested the importance of controlling vehicle numbers and emissions in mega-cities of China as its population and economy continue to grow.

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