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

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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Identification of Regional Drought Processes in North China Using MCI Analysis

Land ◽

10.3390/land10121390 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1390

Author(s):

Xiuhua Cai ◽

Wenqian Zhang ◽

Xiaoyi Fang ◽

Qiang Zhang ◽

Cunjie Zhang ◽

...

Keyword(s):

North China ◽

Significance Test ◽

Severe Drought ◽

Average Intensity ◽

Process Identification ◽

Strength Assessment ◽

Affected Area ◽

The Past ◽

Identification Method ◽

Regional Drought

Comprehensive identification of drought events is of great significance for monitoring and evaluating drought processes. Based on the date of daily precipitation, temperature and drought-affected area of 403 meteorological stations in North China from 1960 to 2019, the Comprehensive Drought Process Intensity Index (CDPII) has been developed by using the Meteorological-drought Composite Index (MCI) and regional drought process identification method, as well as the EIDR theory method. The regional drought processes in the past 60 years in North China, including Beijing, Tianjin, Hebei, Shanxi and Middle Inner Mongolia, were analyzed and identified. The result shows that the distribution characteristic of droughts with different intensities is as follows: The number of days of all annual-average mild droughts, moderate droughts and severe droughts was highest in Tianjin and that of extreme droughts was highest in Shanxi. The number of days of mild droughts was highest in May and lowest in January. The number of days of moderate droughts was highest in June. The number of days with mild and moderate drought showed an overall increasing trend, while the number of days with severe drought and above showed an overall decreasing trend (through a 95% significance test). The number of drought days was the highest in the 1990s. The annual frequency of drought is between 66.7% and 86.7%; the drought frequency in Hebei is the highest at 86.7%, followed by Beijing at 80%. There were 75 regional drought processes in North China from 1960 to 2019, and the correlation coefficient between process intensity and the drought-affected area was 0.55, which passed the 99% significance test. The comprehensive intensity of drought process from 27 April to 1 September 1972 was the strongest. From 18 May to 31 October 1965, the drought lasted 167 days. The overall drought intensity had a slight weakening trend in the past 60 years. A total of 75 regional drought processes occurred in North China, and the process intensity showed a trend of wavy decline with a determination coefficient (R2) of 0.079 (95% significance test). Overall, the regional drought process identification method and strength assessment result tally with the drought disaster, which can better identify the regional drought process. Furthermore, including the last days, the average intensity, average scope comprehensive strength, there are many angles to monitor and evaluate the drought and drought process. These provide a reference for drought control and decision-making.

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The North China/Northeastern Asia Severe Summer Drought in 2014

Journal of Climate ◽

10.1175/jcli-d-15-0202.1 ◽

2015 ◽

Vol 28 (17) ◽

pp. 6667-6681 ◽

Cited By ~ 69

Author(s):

Huijun Wang ◽

Shengping He

Keyword(s):

North China ◽

East Asian ◽

Teleconnection Pattern ◽

Severe Drought ◽

European Continent ◽

The Past ◽

The North ◽

Asian Summer ◽

Silk Road Pattern ◽

The Silk Road

Abstract In summer 2014, north China and large areas of northeastern Asia (NCNEA) suffered from the most severe drought of the past 60 years. This study indicates that the East Asian summer precipitation in 2014 exhibited a tripole anomaly, with severe negative anomalies in NCNEA, strong positive anomalies in south China, South Korea, and Japan, and intense negative anomalies in the western North Pacific. Along with the severe tripole precipitation anomalies, there were strong intensities of the Silk Road pattern, the Pacific–Japan pattern, and the Eurasian teleconnection pattern, which were responsible for the strong precipitation anomaly in 2014 through changes to the western Pacific subtropical high (WPSH) and the East Asian trough. Further analysis indicates that the sea surface temperature (SST) in the North Pacific was nearly the warmest in the past 60 years and, together with the strong SST warming in the warm pool region, thus caused the strong Pacific–Japan teleconnection pattern, southward positioning of the WPSH, and weakened East Asian summer monsoon. Additionally, the summertime sea ice cover in the Arctic Ocean was anomalous, resulting in high SST in the Laptev–Kara Sea and, hence, triggering a strong Eurasian teleconnection pattern and contributing to the severe drought of NCNEA. Furthermore, the intense warming over the European Continent and Caspian Sea favored the Silk Road pattern, also contributing to the southward positioning of the WPSH and the NCNEA drought. The NCNEA severe drought was therefore the joint result of Pacific SST anomalies, Arctic sea ice anomalies, and warming over the European Continent and Caspian Sea.

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

Atmosphere ◽

10.3390/atmos10020095 ◽

2019 ◽

Vol 10 (2) ◽

pp. 95 ◽

Cited By ~ 6

Author(s):

Xinying Wu ◽

Zengchao Hao ◽

Fanghua Hao ◽

Chong Li ◽

Xuan Zhang

Keyword(s):

High Frequency ◽

North China ◽

Southwest China ◽

Temporal Variations ◽

Central China ◽

Spatial Extent ◽

Monthly Precipitation ◽

Regional Patterns ◽

Increasing Trend ◽

The Individual

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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Analysis on the Causes of Severe Drought in North China in Winter of 2008-2009

Arid Zone Research ◽

10.3724/sp.j.1148.2010.00182 ◽

2010 ◽

Vol 27 (2) ◽

pp. 182-187 ◽

Cited By ~ 2

Author(s):

Quan-liang CHEN ◽

Wei HUA ◽

Guang-ming XIONG ◽

Hui XU ◽

Xiao-ran LIU

Keyword(s):

North China ◽

Severe Drought

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The Kalam Cosmological Argument

10.1093/oso/9780190842215.003.0024 ◽

2018 ◽

Cited By ~ 1

Author(s):

William Lane Craig

Keyword(s):

Space Time ◽

Cosmological Argument ◽

Philosophical Literature ◽

The Past ◽

Classical Space ◽

Kalam Cosmological Argument ◽

Kalām Cosmological Argument ◽

The Universe

A survey of recent philosophical literature on the kalam cosmological argument reveals that arguments for the finitude of the past and, hence, the beginning of the universe remain robust. Plantinga’s brief criticisms of Kant’s argument in his First Antinomy concerning time are shown not to be problematic for the kalam argument. This chapter addresses, one by one, the two premises of the kalam, focusing on their philosophical aspects. The notion of infinity, both actual and potential, is discussed in relation to the coming into being of the universe. In addition, the scientific aspects of the two premises are also, briefly, addressed. Among these are the Borde-Guth-Vilenkin theorem, which proves that classical space-time cannot be extended to past infinity but must reach a boundary at some time in the finite past. This, among other factors, lends credence to the kalam argument’s second premise.

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Exploring the past of Mavrovouni forest in the Pindus Mountain range (Greece) using tree rings of Bosnian pines

Trees ◽

10.1007/s00468-021-02189-6 ◽

2021 ◽

Author(s):

Anastasia Christopoulou ◽

Nikolaos M. Fyllas ◽

Barbara Gmińska-Nowak ◽

Yasemin Özarslan ◽

Margarita Arianoutsou ◽

...

Keyword(s):

Fire History ◽

Ring Width ◽

Severe Drought ◽

Mountain Range ◽

Degree Days ◽

Mature Trees ◽

The Past ◽

Natural Agent ◽

Fire Ignition ◽

Animal Grazing

Abstract Key message Long Bosnian pine chronologies from different mountains are shaped by different climatic parameters and can help identify past drought events and reconstruct landscape histories. Abstract We developed a 735-year-long Pinus heldreichii chronology from the southern distribution limit of the species, expanding the available database of long Bosnian pine chronologies. Tree-ring growth was mainly positively correlated with growing degree days (GDD: r1950–2018 = 0.476) while higher temperatures during both winter and growing season also enhanced growth (TWT: r1950–2018 = 0.361 and TGS: 0.289, respectively). Annual precipitation, during both calendar and water years, had a negative but weaker impact on annual tree growth. The newly developed chronology correlates well with chronologies developed from the neighboring mountains. The years with ring width index (RWI) lower than the average were found to correspond to cool years with dry summers. Still, the newly developed chronology was able to capture severe drought events, such as those in 1660, 1687, and 1725. Several old living trees had internal scars presumably caused by fires. Therefore, old mature trees could be used for fire history reconstruction in addition to climate reconstruction. Although the presence of lightning scars indicates an important natural agent of fire ignition, human activities associated with animal grazing could also be an underlying reason for fires in the region.

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POS1280 SPINAL LOCATION OF TUBERCULOSIS: WHAT HAS CHANGED OVER THE LAST YEARS?

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.3365 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 923.3-923

Author(s):

S. Boussaid ◽

M. Mrabet ◽

S. Jemmali ◽

H. Sahli ◽

H. Ajlani ◽

...

Keyword(s):

Neurological Complications ◽

Developing Nations ◽

Lumbar Pain ◽

X Rays ◽

Resonance Imaging ◽

Vertebral Collapse ◽

The Past ◽

Significant Difference ◽

Tuberculous Spondylodiscitis ◽

Different Parts

Background:Tuberculosis (TB) is no longer a disease limited to developing nations and is still a major cause of significant morbidity and mortality worldwide. It can affect the different parts of the spine.Objectives:The aim of this study was to determine the preferred spinal location of TB.Methods:We conduct a retrospective and descriptive study in a single rheumatology department. Data were collected from observations of patients hospitalized in the past 20 years (2000-2020) who have been diagnosed with tuberculous spondylodiscitis (TS).Results:Fifty-two patients were included (37F/15M). Their mean age was 55.21 years ± 17.79 [19-91]. TS was more frequently unifocal (75%) than multifocal (25%). Lumbar spine involvement was the most common (57.7%) and more frequent in women (63.3%) but with no statistically significant difference (p = 0.2). Other localizations were described such as: dorso-lumbar (21.2%), dorsal (15.4%), lumbosacral (3.8%) and cervical (1.9%). Lumbar pain was present in 34 patients (65.4%) and 29 patients (55.8%) suffered from segmental lumbar stiffness. Imaging was contributive by showing the vertebral location using standard X-rays, computed tomography and magnetic resonance imaging. Disc pinch, erosion of vertebral plateaus and vertebral collapse were the major signs (82.7%, 65.4% and 67.3%, respectively).Conclusion:TS is a rare but serious clinical condition which may lead to severe deformity and early or late neurological complications. Spinal involvement is often unifocal and mostly diagnosed with lumbar pain or stiffness. Multifocal forms, touching several parts of the spine, however remain rare. Our findings remain consistent with those of the literature.Disclosure of Interests:None declared

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Urinary stone composition analysis and clinical characterization of 1520 patients in central China

Scientific Reports ◽

10.1038/s41598-021-85723-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daling Zhang ◽

Songchao Li ◽

Zhengguo Zhang ◽

Ningyang Li ◽

Xiang Yuan ◽

...

Keyword(s):

Calcium Oxalate ◽

Urinary Stone ◽

Geographic Region ◽

Central China ◽

Urinary Stones ◽

Composition Analysis ◽

Stone Composition ◽

Calcium Oxalate Stones ◽

Significant Difference ◽

Lower Urinary

AbstractA total of 1520 patients with urinary stones from central China were collected and analysed by Fourier transform infrared spectroscopy between October 1, 2016 and December 31, 2019. For all patients, age, sex, comorbidities, stone location, laboratory examination and geographic region were collected. The most common stone component was calcium oxalate (77.5%), followed by calcium phosphate (8.7%), infection stone (7.6%), uric acid (UA) stone (5.3%)and cystine (0.9%). The males had more calcium oxalate stones (p < 0.001), while infection stone and cystine stones occurred more frequently in females (p < 0.001). The prevalence peak occurred at 41–60 years in both men and women. UA stones occurred frequently in patients with lower urinary pH (p < 0.001), while neutral urine or alkaline urine (p < 0.001) and urinary infection (p < 0.001) were more likely to be associated with infection stone stones. Patients with high levels of serum creatinine were more likely to develop UA stones (p < 0.001). The proportion of UA stones in diabetics was higher (p < 0.001), and the incidence of hypertension was higher in patients with UA stones (p < 0.001). Compared to the other types, more calcium oxalate stones were detected in the kidneys and ureters (p < 0.001), whereas struvite stones were more frequently observed in the lower urinary tract (p = 0.001). There was no significant difference in stone composition across the Qinling-Huaihe line in central China except UA stones, which were more frequently observed in patients south of the line (p < 0.001).

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Levels of Evidence in Rhinology and Skull Base Surgery Research

Otolaryngology ◽

10.1177/0194599820987131 ◽

2021 ◽

pp. 019459982098713

Author(s):

Jennifer A. Silver ◽

Marco Mascarella ◽

George Tali ◽

Rickul Varshney ◽

Marc A. Tewfik ◽

...

Keyword(s):

Skull Base ◽

Skull Base Surgery ◽

Absolute Number ◽

High Quality ◽

Level Of Evidence ◽

Levels Of Evidence ◽

The Past ◽

Significant Difference ◽

Surgery Research ◽

Based Medicine

Objective The purpose of this study was to evaluate the quality of evidence of rhinology and rhinologic skull base surgery (RSBS) research and its evolution over the past decade. Study Design Review article. Setting We reviewed articles from 2007 to 2019 in 4 leading peer-reviewed otolaryngology journals and 3 rhinology-specific journals. Methods The articles were reviewed and levels of evidence were assigned using the Oxford Centre for Evidence-Based Medicine 2011 guidelines. High quality was defined as level of evidence 1 or 2. Results In total, 1835 articles were reviewed in this study spanning a 13-year period. Overall, the absolute number of RSBS publications increased significantly 22.6% per year, from 108 articles in 2007 to 481 in 2019 ( P < .001; 95% CI, 7.9-37.2). In 2007, only 13 articles, or 15%, were high quality, and this grew to 146 articles, or 39%, in 2019. A 14.0% per year exponential increase in the number of high-quality publications was found to be statistically significant ( P < .001; 95% CI, 7.2, 20.7). Overall, high-quality publications represented just 25.8% of RSBS articles overall. There was no significant difference in quality between rhinology-specific journals and general otolaryngology journals (χ2 = 3.1, P = .077). Conclusion The number of overall publications and of high-quality RSBS publications has significantly increased over the past decade. However, the proportion of high-quality studies continues to represent a minority of total RSBS research.

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Assessment of the Use of Humidified Nasal Cannulas for Oxygen Therapy in Patients with Epistaxis

ORL ◽

10.1159/000514460 ◽

2021 ◽

pp. 1-5

Author(s):

Jingjing Liu ◽

Tengfang Chen ◽

Zhenggang Lv ◽

Dezhong Wu

Keyword(s):

Flow Rate ◽

Oxygen Therapy ◽

Preliminary Investigation ◽

Nasal Cannula ◽

Low Flow ◽

Antiplatelet Drugs ◽

Flow Rates ◽

The Past ◽

Oxygen Inhalation ◽

Significant Difference

Introduction: In China, nasal cannula oxygen therapy is typically humidified. However, it is difficult to decide whether to suspend nasal cannula oxygen inhalation after the nosebleed has temporarily stopped. Therefore, we conducted a preliminary investigation on whether the use of humidified nasal cannulas in our hospital increases the incidence of epistaxis. Methods: We conducted a survey of 176,058 inpatients in our hospital and other city branches of our hospital over the past 3 years and obtained information concerning their use of humidified nasal cannulas for oxygen inhalation, nonhumidified nasal cannulas, anticoagulant and antiplatelet drugs, and oxygen inhalation flow rates. This information was compared with the data collected at consultation for epistaxis during these 3 years. Results: No significant difference was found between inpatients with humidified nasal cannulas and those without nasal cannula oxygen therapy in the incidence of consultations due to epistaxis (χ2 = 1.007, p > 0.05). The same trend was observed among hospitalized patients using anticoagulant and antiplatelet drugs (χ2 = 2.082, p > 0.05). Among the patients with an inhaled oxygen flow rate ≥5 L/min, the incidence of ear-nose-throat (ENT) consultations due to epistaxis was 0. No statistically significant difference was found between inpatients with a humidified oxygen inhalation flow rate <5 L/min and those without nasal cannula oxygen therapy in the incidence of ENT consultations due to epistaxis (χ2 = 0.838, p > 0.05). A statistically significant difference was observed in the incidence of ENT consultations due to epistaxis between the low-flow nonhumidified nasal cannula and nonnasal cannula oxygen inhalation groups (χ2 = 18.428, p < 0.001). The same trend was observed between the 2 groups of low-flow humidified and low-flow nonhumidified nasal cannula oxygen inhalation (χ2 = 26.194, p < 0.001). Discussion/Conclusion: Neither high-flow humidified nasal cannula oxygen inhalation nor low-flow humidified nasal cannula oxygen inhalation will increase the incidence of recurrent or serious epistaxis complications; the same trend was observed for patients who use anticoagulant and antiplatelet drugs. Humidification during low-flow nasal cannula oxygen inhalation can prevent severe and repeated epistaxis to a certain extent.

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