Spatial and Temporal Variations of Compound Droughts and Hot Extremes in China

Droughts and hot extremes may lead to tremendous impacts on the ecosystem and different sectors of the society. A variety of studies have been conducted on the variability of the individual drought or hot extreme in China. However, the evaluation of compound droughts and hot extremes, which may induce even larger impacts than the individual drought or hot extreme, is still lacking. The aim of this study is to investigate changes in the frequency and spatial extent of compound droughts and hot extremes during summer in China using monthly precipitation and daily temperature data from 1953 to 2012. Results show that a high frequency of compound droughts and hot extremes mostly occur in the regions stretching from northeast to southwest of China. There is an overall increase in the frequency of co-occurrence of droughts and hot extremes across most parts of China with distinct regional patterns. In addition, an increasing trend in the areas covered by compound extremes has been observed, especially after the 1990s. At regional scales, the increase of the frequency and spatial extent of compound extremes has been shown to be most profound in North China (NC), South China (SC), and Southwest China (SWC), while the decrease of compound extremes was found in Central China (CC). These results show the variability of compound droughts and hot extremes and could provide useful insights into the mitigation efforts of extreme events in China.

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Spatiotemporal pattern mining of drought in the last 40 years in China based on the SPEI index and space-time cube

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-21-0049.1 ◽

2021 ◽

Author(s):

Dehe Xu ◽

Qi Zhang ◽

Yan Ding ◽

De Zhang

Keyword(s):

North China ◽

Pattern Mining ◽

Space Time ◽

Central China ◽

Spatiotemporal Pattern ◽

Severe Drought ◽

Monthly Precipitation ◽

Hotspot Analysis ◽

The Past ◽

Significant Difference

AbstractDrought is a common natural disaster that greatly affects the crop yield and water supply in China. However, the spatiotemporal characteristics of drought in China are not well understood. This paper explores the spatial and temporal distributions of droughts in China over the past 40 years using multiscale standardized precipitation evapotranspiration index (SPEI) values calculated by monthly precipitation and temperature data from 612 meteorological stations in China from 1980 to 2019 and combines the space-time cube (STC), Mann-Kendall (M-K) test, emerging spatiotemporal hotspot analysis, spatiotemporal clustering and local outliers for the analysis. The results were as follows: 1) the drought frequency and STC show that there is a significant difference in the spatiotemporal distribution of drought in China, with the most severe drought in Northwest China, followed by the western part of Southwest China and the northern part of North China. 2) The emerging spatiotemporal hotspot analysis of SPEI6 over the past 40 years reveals two cold spots in subregion 4, indicating that future droughts in the region will be more severe. 3) A local outlier analysis of the multiscale SPEI yields a low-low outlier in western North China, indicating relatively more severe year-round drought in this area than in other areas. The low-high outlier in central China indicates that this region was not dry in the past and that drought will become more severe in this region in the future.

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Analysis on the Characteristics of Ordinary and More Serious Accidents in Building Projects in China from 2005 to 2016

MATEC Web of Conferences ◽

10.1051/matecconf/201820602012 ◽

2018 ◽

Vol 206 ◽

pp. 02012

Author(s):

Hui Zhang ◽

Xuewei Ji ◽

Aizhi Wu

Keyword(s):

Economic Growth ◽

Construction Projects ◽

North China ◽

Regional Economy ◽

Southwest China ◽

Central China ◽

Building Projects ◽

The Sustainable Development ◽

Low Incidence ◽

Pie Chart

In China, the frequent safety accidents in building projects seriously affect the sustainable development of construction projects. The paper makes a statistical analysis on the characteristics of ordinary and more serious accidents in building projects from the types of accidents, the trends of development and the characteristics of geographical distribution from 2005 to 2016 in China by using the histogram, trend chart, pie chart and table. It can be concluded that in the recent 12 years, the security situation of construction projects generally fluctuates in a big way and is still not optimistic. Among the five major types of accidents, the electric shock and the lifting accidents have been maintained at a relatively stable and low incidence, and the sloughing accidents have accounted for more than half of the proportion. Accidents concentrated in East China, Central China, North China and Southwest China. The economic development in all provinces and cities in China is positively related to the accident. The greater the total regional economy, the rate of economic growth and the demand for infrastructure construction, the more deaths and accidents in construction projects in the corresponding regions.

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Regional Temporal and Spatial Trends in Drought and Flood Disasters in China and Assessment of Economic Losses in Recent Years

10.20944/preprints201811.0340.v1 ◽

2018 ◽

Author(s):

Jieming Chou ◽

Tian Xian ◽

Wenjie Dong ◽

Yuan Xu

Keyword(s):

Extreme Precipitation ◽

Southwest China ◽

Yangtze River Basin ◽

Standardized Precipitation Index ◽

Central China ◽

Economic Losses ◽

Severe Drought ◽

Precipitation Trend ◽

Flood Disasters ◽

Increasing Trend

Understanding the distribution in drought and floods plays an important role in disaster risk management. The present study aims to explore the trends in the standardized precipitation index and extreme precipitation days in China, as well as to estimate the economic losses they cause. We found that in the Northeast China, northern of North China and northeast of Northwest China were severely affected by drought disasters (average damaged areas were 6.44 million hectares) and the most severe drought trend was located in West China. However, in the north of East China and Central China, the northeastern of the Southwest China was severely affected by flood disasters (average damaged areas were 3.97 million hectares) and the extreme precipitation trend is increasing in the northeastern of the Southwest China. In the Yangtze River basin, there were increasing trends in terms of drought and extreme precipitation, especially in the northeastern of the Southwest China, where accompanied by severe disaster losses. By combining the trends in drought and extreme precipitation days with the distribution of damaged areas, we found that the increasing trend in droughts shifted gradually from north to south, especially in the Southwest China, and the increasing trend in extreme precipitation gradually shifted from south to north.

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Relationship between psychological suzhi and internet addiction among chinese college students

Journal of Systems and Information Technology ◽

10.1108/jsit-07-2020-0127 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Yuan-yan Hu ◽

Peng Wang ◽

Xin-qiang Wang ◽

Tian-qiang Hu

Keyword(s):

College Students ◽

Internet Addiction ◽

North China ◽

Southwest China ◽

Significant Negative Correlation ◽

Hierarchical Regression ◽

Content Type ◽

Chinese College Students ◽

College Sample ◽

The Relationship

Purpose Despite concerns about the effect of internet addiction, little is known about how psychological suzhi impacts the internet addiction of college students. This paper aims to investigate the relationship between psychological suzhi and internet addiction among college students. Design/methodology/approach Using the college student psychological suzhi scale and internet addiction test, 2,070 college students from 11 universities in North China, East China, South China and Southwest China were tested. Findings The detection rate of internet addiction in this college sample of students was 18.8%. There was a significant negative correlation between students’ psychological suzhi and internet addiction (r = −0.408, p < 0.01). Hierarchical regression analysis showed that adaptability and individuality in psychological suzhi significantly negatively predicted college students’ internet addiction tendency (p < 0.001). Originality/value This study is the first to show a relationship between psychological suzhi and internet addiction in college students. In detail, the adaptability and individuality of college students’ psychological suzhi are protective factors related to internet addiction. The results also suggested that the authors can prevent and intervene in internet addiction by modifying college students’ adaptability and individuality.

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Pico de velocidade de crescimento em antropometria e composição corporal de escolares

Brazilian Journal of Kinanthropometry and Human Performance ◽

10.5007/1980-0037.2017v19n3p309 ◽

2017 ◽

Vol 19 (3) ◽

pp. 309

Author(s):

Edilson Hobold ◽

Lucinar Jupir Forner Flores ◽

Ricardo Brandt ◽

Oldemar Mazzardo Junior ◽

Miguel De Arruda

Keyword(s):

Body Composition ◽

Body Fat ◽

Linear Growth ◽

Linear Trend ◽

Peak Height ◽

Male Students ◽

Height Velocity ◽

Peak Height Velocity ◽

Increasing Trend ◽

The Individual

The aim of this study was to analyze the age of Peak Height Velocity (PHV), anthropometric variables and body composition of students from the western state of Paraná. he study included 1,011 male students aged 12-15 years from 11 municipalities located around the Itaipu lake. Anthropometric and body composition variables were obtained according to international criteria. Biological maturation was determined by age of PHV and for the purpose of analysis, it was categorized into developmental levels. The results reinforce, as expected, an increasing trend of variables analyzed as students advanced in maturity. hus, it was concluded that with the advancement of maturation, anthropometric variables maintain a linear growth observed in each PHV stratum. his linear trend is not observed in body composition. Body fat showed a decrease in average values as the individual approaches PHV.

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Impact of VOCs on the formation of ozone in a central China city during severe pollution periods

10.5194/acp-2018-397 ◽

2018 ◽

Author(s):

Bowei Li ◽

Steven Sai Hang Ho ◽

Sunling Gong ◽

Jingwei Ni ◽

Huairui Li ◽

...

Keyword(s):

Temporal Variations ◽

Central China ◽

Compressed Natural Gas ◽

Pmf Model ◽

Sampling Campaign ◽

Time Period ◽

Ozone Formation Potential ◽

Range Transport ◽

Volatile Organic ◽

First Time

Abstract. In this work, a five-month sampling campaign was conducted for volatile organic compounds (VOCs) for the first time in Zhengzhou City, Henan province, China, where ozone (O3) pollution has shown an increasing trend in recent years. Fifty-seven VOCs defined by the Photochemical Assessment Monitoring Stations (PAMS) were sampled using canister method. Meanwhile, other O3 precursor gases were monitored online at four different sites between the time period of May–September, 2017. The results indicated that the average mixing ratio of ΣPAMS (31.57 ± 23.35 ppbv) in Zhengzhou was lower than the other megacities in China, while alkyne was in a significantly higher proportion. The abundances, compositions and ratios of PAMS showed strong spatial and temporal variations. Alkenes were the largest contributors to the ozone formation potential (OFP). On clear days, higher O3 levels were often accompanied with high ΣPAMS/NOx ratio at each site, demonstrating that the VOCs were more sensitive during the O3 formation period in Zhengzhou. Furthermore, source apportionmemt was conducted with Positive Matrix Factorization (PMF) model, and it was found that the use of compressed natural gas (CNG), the evaporation of gasoline and the exhaust from vehicles were the important sources for ambient VOCs at all four sites. Besides, the meterological conditions and long-range transport from other surrounding provinces also had an impact on the air quality determined using the cluster analysis. It is worth mentioning that the reduction in VOCs' emissions is necessary to suppress the O3 pollution.

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Aurora and open magnetic flux during isolated substorms, sawteeth, and SMC events

Annales Geophysicae ◽

10.5194/angeo-25-1865-2007 ◽

2007 ◽

Vol 25 (8) ◽

pp. 1865-1876 ◽

Cited By ~ 30

Author(s):

A. D. DeJong ◽

X. Cai ◽

R. C. Clauer ◽

J. F. Spann

Keyword(s):

Magnetic Flux ◽

Temporal Variations ◽

Auroral Oval ◽

Polar Cap ◽

Expansion Phase ◽

Magnetospheric Convection ◽

Open Magnetic Flux ◽

Open Flux ◽

The Individual

Abstract. Using Polar UVI LBHl and IMAGE FUV WIC data, we have compared the auroral signatures and polar cap open flux for isolated substorms, sawteeth oscillations, and steady magnetospheric convection (SMC) events. First, a case study of each event type is performed, comparing auroral signatures and open magnetic fluxes to one another. The latitude location of the auroral oval is similar during isolated substorms and SMC events. The auroral intensity during SMC events is similar to that observed during the expansion phase of an isolated substorm. Examination of an individual sawtooth shows that the auroral intensity is much greater than the SMC or isolated substorm events and the auroral oval is displaced equatorward making a larger polar cap. The temporal variations observed during the individual sawtooth are similar to that observed during the isolated substorm, and while the change in polar cap flux measured during the sawtooth is larger, the percent change in flux is similar to that measured during the isolated substorm. These results are confirmed by a statistical analysis of events within these three classes. The results show that the auroral oval measured during individual sawteeth contains a polar cap with, on average, 150% more magnetic flux than the oval measured during isolated substorms or during SMC events. However, both isolated substorms and sawteeth show a 30% decrease in polar cap magnetic flux during the dipolarization (expansion) phase.

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Gaseous and particulate urban air pollution in the region of Vojvodina (Serbia)

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1528087m ◽

2015 ◽

pp. 87-97

Author(s):

Slavica Malinovic-Milicevic ◽

Dragutin Mihailovic ◽

Emilija Nikolic-Djoric ◽

Marija Jevtic

Keyword(s):

Air Pollution ◽

Urban Air Pollution ◽

Temporal Variations ◽

Heating Season ◽

Limit Values ◽

Substantial Impact ◽

Pollution Levels ◽

Positive Effects ◽

Increasing Trend ◽

Calm Wind

The present study focuses on interpretations of the temporal variations and variations between urban locations of sulfur dioxide (SO2), nitrogen dioxide (NO2) and black smoke (BS) during the period 2001-2008 in the Vojvodina Region of Serbia (VR_S). In this study we examined variations of pollutants concentrations during household heating and non-heating seasons and the effect of household heating, traffic, rainfall and wind speed on the air pollution levels of SO2, NO2 and BS in eight locations. The analyses showed that the annual limit values of these pollutants as recommended by the Serbian regulations and recommendations were not exceeded, unlike the daily limits. Higher SO2 concentrations during household heating season in four locations indicate the substantial impact of house?hold heating on air quality. Positive effects of the use of environmentally cleaner fuels were observed in only two locations. The growing impact of traffic on air pollution is shown by the increasing trend of NO2 during both seasons. Calm wind conditions and an absence of rainfall were found to have incremental effects on pollution levels in most locations.

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Supplemental Material: Late Triassic successive amalgamation between the South China and North China blocks: Insights from structural analysis and magnetic fabrics study of the Bikou Terrane and its adjacent area, northwestern Yangtze block, central China

10.1130/gsab.s.17124278.v1 ◽

2021 ◽

Author(s):

Zhenhua Xue ◽

Wei Lin ◽

et al.

Keyword(s):

North China ◽

Stereographic Projection ◽

Magnetic Hysteresis ◽

Central China ◽

Late Triassic ◽

Adjacent Area ◽

Yangtze Block ◽

Data Set ◽

Basic Principles ◽

Magnetic Fabrics

Text: Basic principles of anisotropy of magnetic susceptibility (AMS); Figure S1: Photographs of supplementary shearing indicators of the structural kinematics; Figure S2: Complete magnetic hysteresis data set for specimen selected from 34 sites; Figure S3: Measurements of isothermal remanent magnetization of specimen selected from 34 representative sites of the Bikou Terrane; Figure S4: Thermo-magnetic experiments of specimen selected from 12 representative sites; Figure S5: Mrs/Ms versus Hcr/Hc diagram from the selected specimen of the representative sites to define the size of magnetite; Figure S6: Stereographic projection of the AMS directional fabrics and structural fabrics.

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Spatial and temporal variations of CO<sub>2</sub> mole fractions observed at Beijing, Xianghe and Xinglong in North China

10.5194/acp-2021-103 ◽

2021 ◽

Author(s):

Yang Yang ◽

Minqiang Zhou ◽

Ting Wang ◽

Bo Yao ◽

Pengfei Han ◽

...

Keyword(s):

Seasonal Variations ◽

Human Activities ◽

North China ◽

Terrestrial Ecosystem ◽

Temporal Variations ◽

Spatial And Temporal Variations ◽

Boundary Layer Height ◽

The Mean ◽

The Impact ◽

First Time

Abstract. Atmospheric CO2 mole fractions are observed at Beijing (BJ), Xianghe (XH), and Xinglong (XL) in North China using the Picarro G2301 Cavity Ring-Down Spectroscopy instruments. The measurement system is described comprehensively for the first time. The geo-distances among these three sites are within 200 km, but they have very different surrounding environments: BJ is inside the megacity; XH is in the suburban area; XL is in the countryside on a mountain. The mean and standard deviation of CO2 mole fractions at BJ, XH, and XL between October 2018 and September 2019 are 448.4 ± 12.8 ppm, 436.0 ± 9.2 ppm and 420.6 ± 8.2 ppm, respectively. The seasonal variations of CO2 at these three sites are similar, with a maximum in winter and a minimum in summer, which is dominated by the terrestrial ecosystem. However, the seasonal variations of CO2 at BJ and XH are more affected by human activities as compared to XL. By using CO2 at XL as the background, CO2 enhancements are observed simultaneously at BJ and XH. The diurnal variations of CO2 are driven by the boundary layer height, photosynthesis and human activities at BJ, XH and XL. Moreover, we address the impact of the wind on the CO2 mole fractions at BJ and XL. This study provides an insight into the spatial and temporal variations of CO2 mole fractions in North China.

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