scholarly journals Identification of Regional Drought Processes in North China Using MCI Analysis

Land ◽  
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.

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

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.

Comprehensive assessment and variation characteristics of the drought intensity in North China based on EID

2022 ◽  
Keyword(s):  
North China ◽  
Maximum Intensity ◽  
Stage I ◽  
Stage Ii ◽  
Severe Drought ◽  
Average Intensity ◽  
Drought Frequency ◽  
Drought Intensity ◽  
Increasing Trend ◽  
Variation Characteristics

Abstract Under the new background of climate change, it is very important to identify the characteristics of drought in North China. Based on the daily Meteorological Drought Comprehensive Index from 494 national meteorological stations in North China during 1961–2019, the drought processes and their intensity are identified by applying the ‘extreme’ intensity-duration theory. Then, the stage variation characteristics of the drought trend, the average drought intensity and the drought frequency are analyzed. The results show that among the five drought intensity indexes the process maximum intensity demonstrates the greatest correlation coefficient with the disaster rate of drought in North China. Therefore, the process maximum intensity of drought is selected as the annual drought intensity to analyze the drought characteristics in North China. According to the climate warming trends, the study period is divided into three stages, i.e., 1951–1984 (stage I), 1985–1997 (stage II) and 1998–2019(stage III). The comprehensive results show that the drought intensity in North China has significant stage characteristics. In stage I, the drought shows an increasing trend in most parts of North China, but its average intensity is relatively weaker, with a lower severe drought frequency. The drought also shows an increasing trend in most parts in stage II, with a more significant increase rate than that in stage I, and the average drought intensity is the strongest and the severe drought frequency is the highest. In stage III, the drought shows a decreasing trend in some areas, and the average intensity is the weakest, with a lower severe drought frequency.

scholarly journals The North China/Northeastern Asia Severe Summer Drought in 2014

2015 ◽  
Vol 28 (17) ◽  
pp. 6667-6681 ◽  
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.

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

2010 ◽  
Vol 27 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Quan-liang CHEN ◽  
Wei HUA ◽  
Guang-ming XIONG ◽  
Hui XU ◽  
Xiao-ran LIU
Keyword(s):  
North China ◽  
Severe Drought

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

Trees ◽  
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.

scholarly journals Denitrifying pathways dominate nitrous oxide emissions from managed grassland during drought and rewetting

2021 ◽  
Vol 7 (6) ◽  
pp. eabb7118
Author(s):  
E. Harris ◽  
E. Diaz-Pines ◽  
E. Stoll ◽  
M. Schloter ◽  
S. Schulz ◽  
...  
Keyword(s):  
Growth Rate ◽  
Nitrous Oxide ◽  
N Fertilization ◽  
High Variability ◽  
Nitrous Oxide Emissions ◽  
Severe Drought ◽  
Total N ◽  
The Past ◽  
Precipitation Changes ◽  
Isotopic Measurements

Nitrous oxide is a powerful greenhouse gas whose atmospheric growth rate has accelerated over the past decade. Most anthropogenic N2O emissions result from soil N fertilization, which is converted to N2O via oxic nitrification and anoxic denitrification pathways. Drought-affected soils are expected to be well oxygenated; however, using high-resolution isotopic measurements, we found that denitrifying pathways dominated N2O emissions during a severe drought applied to managed grassland. This was due to a reversible, drought-induced enrichment in nitrogen-bearing organic matter on soil microaggregates and suggested a strong role for chemo- or codenitrification. Throughout rewetting, denitrification dominated emissions, despite high variability in fluxes. Total N2O flux and denitrification contribution were significantly higher during rewetting than for control plots at the same soil moisture range. The observed feedbacks between precipitation changes induced by climate change and N2O emission pathways are sufficient to account for the accelerating N2O growth rate observed over the past decade.

scholarly journals Over-Optimistic Projected Future Wheat Yield Potential in the North China Plain: The Role of Future Climate Extremes

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 145
Author(s):  
Rui Yang ◽  
Panhong Dai ◽  
Bin Wang ◽  
Tao Jin ◽  
Ke Liu ◽  
...  
Keyword(s):  
Drought Stress ◽  
North China Plain ◽  
North China ◽  
Crop Yields ◽  
Wheat Yield ◽  
Yield Potential ◽  
Severe Drought ◽  
The North ◽  
The North China Plain ◽  
Stress Environments

Global warming and altered precipitation patterns pose a serious threat to crop production in the North China Plain (NCP). Quantifying the frequency of adverse climate events (e.g., frost, heat and drought) under future climates and assessing how those climatic extreme events would affect yield are important to effectively inform and make science-based adaptation options for agriculture in a changing climate. In this study, we evaluated the effects of heat and frost stress during sensitive phenological stages at four representative sites in the NCP using the APSIM-wheat model. climate data included historical and future climates, the latter being informed by projections from 22 Global Climate Models (GCMs) in the Coupled Model Inter-comparison Project phase 6 (CMIP6) for the period 2031–2060 (2050s). Our results show that current projections of future wheat yield potential in the North China Plain may be overestimated; after more accurately accounting for the effects of frost and heat stress in the model, yield projections for 2031-60 decreased from 31% to 9%. Clustering of common drought-stress seasonal patterns into key groups revealed that moderate drought stress environments are likely to be alleviated in the future, although the frequency of severe drought-stress environments would remain similar (25%) to that occurring under the current climate. We highlight the importance of mechanistically accounting for temperature stress on crop physiology, enabling more robust projections of crop yields under future the burgeoning climate crisis.

Drought dynamics and variability over Bundelkhand region of central India: Past, Present and Future

2021 ◽  
Author(s):  
Md Saquib Saharwardi ◽  
Aditya Kumar Dubey ◽  
Pankaj Kumar ◽  
Dmitry V. Sein
Keyword(s):  
Climate Model ◽  
Monsoon Season ◽  
Science And Technology ◽  
Regional Climate ◽  
Standardized Precipitation Index ◽  
Central India ◽  
Severe Drought ◽  
Future Projection ◽  
Russian Science ◽  
Regional Drought

<p>In the present study, an evaluation of the past, present, and future variability of droughts in the Bundelkhand region of Central India are analyzed. Bundelkhand is a severe drought-prone region with intense water stress, where in the last five years four were drought. Therefore, understanding the drivers of drought over the region and its future projection is quite crucial for regional water management. The assessment has been made by analyzing the observational dataset from 1951-2018 to understand the regional drought dynamics. The future projection is made using a multi-model ensemble from a regional climate model over the CORDEX South-Asia domain under the highest emission scenario. The Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) indices are used to understand present drought and its future projection. In addition to this, drought driving parameters like precipitation, temperature, sea-surface temperature wind circulation has been assessed to understand the regional drought dynamics. The composite analysis of drought indicates that the moisture-laden low-level jet from the Arabian Sea branch generally weakened compared to Bay of Bengal branch for monsoon season. Teleconnections of drought over Bundelkhand region shows that nearly half of the droughts are linked to El-Nino events that have become stronger in recent past. The model result reveals that regional climate variability is reasonably captured over the region. In addition, we found increasing drought frequency since the beginning of the 21<sup>st</sup> century. The detailed results from the analysis will be shown briefly in the general assembly.</p><p><strong>Acknowledgement: </strong>This work is jointly supported by the Department of Science and Technology (DST), Govt. of India, grant number DST/INT/RUS/RSF/P-33/G and the Russian Science Foundation (Project No.: 19-47-02015). The first author is also thankful to the Department of Science and Technology (DST), Govt. of India for providing DST INSPIRE fellowship (Grant No. IF160281).</p>

scholarly journals Evaluation of temporal drought variation and projection in a tropical river basin of Kerala

2020 ◽  
Vol 11 (S1) ◽  
pp. 115-132 ◽  
Author(s):  
M. A. Jincy Rose ◽  
N. R. Chithra
Keyword(s):  
River Basin ◽  
Standardized Precipitation Index ◽  
Drought Severity ◽  
Climate Projections ◽  
Severe Drought ◽  
Tropical River ◽  
The Past ◽  
Drought Conditions ◽  
The Future ◽  
The Standardized Precipitation Index

Abstract Temperature is an indispensable parameter of climate that triggers evapotranspiration and has vital importance in aggravating drought severity. This paper analyses the existence and persistence of drought conditions which are said to prevail in a tropical river basin which was once perennial. Past observed data and future climate projections of precipitation and temperature were used for this purpose. The assessment and projection of this study employ the Standardized Precipitation Evapotranspiration Index (SPEI) compared with that of the Standardized Precipitation Index (SPI). The results indicate the existence of drought in the past and the drought conditions that may persist in the future according to RCP 4.5 and 8.5 scenarios. The past drought years identified in the study were compared with the drought declared years in the state and were found to be matching. The evaluation of the future scenarios unveils the occurrence of drought in the basin ranging from mild to extreme conditions. It has been noted that the number of moderate and severe drought months has increased based on SPEI compared to SPI, indicating the importance of temperature in drought studies. The study can be considered as a plausible scientific remark helpful in risk management and application decisions.

Sign in / Sign up

Export Citation Format

Share Document