Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop...Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop cultivation. Increases in the frequency of these rare events in a future warmer climate would have significant societal impact. This study uses an ensemble of 10 Coupled Model Intercomparison Project(CMIP) models to investigate the projected change in agricultural flash drought during the 21st century. Comparison across geographical regions and climatic zones indicates that individual events are preceded by anomalously low relative humidity and precipitation, with long-term trends governed by changes in temperature, relative humidity, and soil moisture. As a result of these processes, the frequency of both upperlevel and root-zone flash drought is projected to more than double in the mid-and high latitudes over the 21st century, with hot spots developing in the temperate regions of Europe, and humid regions of South America, Europe, and southern Africa.展开更多
Flash drought is a rapidly intensifying drought with abnormally high temperature,which has greatly threatened crop yields and water supply,and aroused wide public concern in a warming climate.However,the preferable hy...Flash drought is a rapidly intensifying drought with abnormally high temperature,which has greatly threatened crop yields and water supply,and aroused wide public concern in a warming climate.However,the preferable hydrometeorological conditions for flash drought and its association with conventional drought at longer time scales remain unclear.Here,we investigate two types of flash drought over China:one is high-temperature driven(Type Ⅰ),while the other is water-deficit driven(Type Ⅱ).Results show that the frequencies of the two types of flash drought averaged over China during the growing season are comparable.Type I flash drought tends to occur over southern China,where moisture supply is sufficient,while Type Ⅱ is more likely to occur over semi-arid regions such as northern China.Both types of flash drought increase significantly(p<0.01)during 1979–2010,with a doubled rise in Type Ⅰ as compared with Type Ⅱ.Composite analysis shows that high temperature quickly increases evapotranspiration(ET)and reduces soil moisture from two pentads before the onset of Type Ⅰ flash drought.In contrast,there are larger soil moisture deficits two pentads before the onset of Type Ⅱ flash drought,leading to a decrease in ET and increase in temperature.For flash drought associated with seasonal drought,there is a greater likelihood of occurrence during the onset and recovery phases of seasonal drought,suggesting perfect conditions for flash drought during transition periods.This study provides a basis for the early warning of flash drought by connecting multiscale drought phenomena.展开更多
In a globally warming world,subtropical regions are generally expected to become drier while the tropics and mid–high latitudes become wetter.In line with this,Southwest China,close to 25?N,is expected to become incr...In a globally warming world,subtropical regions are generally expected to become drier while the tropics and mid–high latitudes become wetter.In line with this,Southwest China,close to 25?N,is expected to become increasingly prone to drought if annual mean precipitation decreases.However,despite this trend,changes in the temporal distribution of moisture supply might actually result in increased extreme rainfall in the region,whose climate is characterized by distinct dry and wet seasons.Using hourly and daily gauge observations,rainfall intensity changes since 1971 are examined for a network of 142 locations in the region.From the analysis,dry season changes are negligible but wet season changes exhibit a significantly strong downward trend [-2.4%(10 yr)^(-1)],particularly during the past 15 years [-17.7%(10 yr)^(-1)].However,the intensity of events during the wettest of 5% hours appears to steadily increase during the whole period [1.4%(10 yr)^(-1)],tying in with government statistical reports of recent droughts and flooding.If the opposing trends are a consequence of a warming climate,it is reasonable to expect the contradictory trend to continue with an enhanced risk of flash flooding in coming decades in the region concerned.展开更多
Drought is one of the most serious and extensive natural hazards in the world.Subject to monsoon climate variability,China is particularly influenced by drought hazards,especially meteorological drought.Based on a com...Drought is one of the most serious and extensive natural hazards in the world.Subject to monsoon climate variability,China is particularly influenced by drought hazards,especially meteorological drought.Based on a comprehensive understanding of the current status of international drought research,this paper systematically reviews the history and achievements of drought research in China since the founding of the People’s Republic of China,from four main perspectives:characteristics and spatiotemporal distribution of historical and recent drought events,drought formation mechanism and change trend,drought hazard risk,and the particular flash drought.The progress and problems of drought research in China are analyzed and future prospects are proposed,with emphasis on the multi-factor synergetic effect for drought formation;the effect of land-atmosphere interaction;identification,monitoring,and prediction of flash drought;categorization of drought and characteristics among various types of drought;the agricultural drought development;drought response to climate warming;and assessment of drought hazard risks.It is suggested that strengthening scientific experimental research on drought in China is imperative.The present review is conducive to strategic planning of drought research and application,and may facilitate further development of drought research in China.展开更多
基金supported by the National Centre for Atmospheric Science through the NERC National Capability International Programmes Award (NE/ X006263/1)the Global Challenges Research Fund, via Atmospheric hazard in developing Countries: Risk assessment and Early Warning (ACREW) (NE/R000034/1)the Natural Environmental Research Council and the Department for Foreign International Development through the Sat WIN-ALERT project (NE/ R014116/1)。
文摘Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop cultivation. Increases in the frequency of these rare events in a future warmer climate would have significant societal impact. This study uses an ensemble of 10 Coupled Model Intercomparison Project(CMIP) models to investigate the projected change in agricultural flash drought during the 21st century. Comparison across geographical regions and climatic zones indicates that individual events are preceded by anomalously low relative humidity and precipitation, with long-term trends governed by changes in temperature, relative humidity, and soil moisture. As a result of these processes, the frequency of both upperlevel and root-zone flash drought is projected to more than double in the mid-and high latitudes over the 21st century, with hot spots developing in the temperate regions of Europe, and humid regions of South America, Europe, and southern Africa.
基金supported by the National Key R&D Program of China (2018YFA0606002)the National Natural Science Foundation of China (91547103)+1 种基金the China Special Fund for Meteorological Research in the Public Interest (Grant No. GYHY201506001)the General Financial Grant from the China Postdoctoral Science Foundation (2018M631553)
文摘Flash drought is a rapidly intensifying drought with abnormally high temperature,which has greatly threatened crop yields and water supply,and aroused wide public concern in a warming climate.However,the preferable hydrometeorological conditions for flash drought and its association with conventional drought at longer time scales remain unclear.Here,we investigate two types of flash drought over China:one is high-temperature driven(Type Ⅰ),while the other is water-deficit driven(Type Ⅱ).Results show that the frequencies of the two types of flash drought averaged over China during the growing season are comparable.Type I flash drought tends to occur over southern China,where moisture supply is sufficient,while Type Ⅱ is more likely to occur over semi-arid regions such as northern China.Both types of flash drought increase significantly(p<0.01)during 1979–2010,with a doubled rise in Type Ⅰ as compared with Type Ⅱ.Composite analysis shows that high temperature quickly increases evapotranspiration(ET)and reduces soil moisture from two pentads before the onset of Type Ⅰ flash drought.In contrast,there are larger soil moisture deficits two pentads before the onset of Type Ⅱ flash drought,leading to a decrease in ET and increase in temperature.For flash drought associated with seasonal drought,there is a greater likelihood of occurrence during the onset and recovery phases of seasonal drought,suggesting perfect conditions for flash drought during transition periods.This study provides a basis for the early warning of flash drought by connecting multiscale drought phenomena.
基金supported by the National Natural Science Foundation of China[grant number 41875105]the National Key R&D Program of China[grant number 2018YFA0606002]the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars[grant number BK20211540]。
基金jointly supported by the National Key R&D Program of China(Grant Nos.2016YFE0102400 and 2017YFC1502701)the UK-China Research & Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP) China as part of the Newton Fund
文摘In a globally warming world,subtropical regions are generally expected to become drier while the tropics and mid–high latitudes become wetter.In line with this,Southwest China,close to 25?N,is expected to become increasingly prone to drought if annual mean precipitation decreases.However,despite this trend,changes in the temporal distribution of moisture supply might actually result in increased extreme rainfall in the region,whose climate is characterized by distinct dry and wet seasons.Using hourly and daily gauge observations,rainfall intensity changes since 1971 are examined for a network of 142 locations in the region.From the analysis,dry season changes are negligible but wet season changes exhibit a significantly strong downward trend [-2.4%(10 yr)^(-1)],particularly during the past 15 years [-17.7%(10 yr)^(-1)].However,the intensity of events during the wettest of 5% hours appears to steadily increase during the whole period [1.4%(10 yr)^(-1)],tying in with government statistical reports of recent droughts and flooding.If the opposing trends are a consequence of a warming climate,it is reasonable to expect the contradictory trend to continue with an enhanced risk of flash flooding in coming decades in the region concerned.
基金Supported by the National Natural Science Foundation of China(41630426 and 41575149)China Meteorological Administration Special Public Welfare Research Fund(GYHY201506001-6)。
文摘Drought is one of the most serious and extensive natural hazards in the world.Subject to monsoon climate variability,China is particularly influenced by drought hazards,especially meteorological drought.Based on a comprehensive understanding of the current status of international drought research,this paper systematically reviews the history and achievements of drought research in China since the founding of the People’s Republic of China,from four main perspectives:characteristics and spatiotemporal distribution of historical and recent drought events,drought formation mechanism and change trend,drought hazard risk,and the particular flash drought.The progress and problems of drought research in China are analyzed and future prospects are proposed,with emphasis on the multi-factor synergetic effect for drought formation;the effect of land-atmosphere interaction;identification,monitoring,and prediction of flash drought;categorization of drought and characteristics among various types of drought;the agricultural drought development;drought response to climate warming;and assessment of drought hazard risks.It is suggested that strengthening scientific experimental research on drought in China is imperative.The present review is conducive to strategic planning of drought research and application,and may facilitate further development of drought research in China.
