NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 1...NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007.The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part.As a result,relationships between an atmospheric heating source(hereafter called <Q_1>) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper.The results are shown as follows.The flood/drought to the north of Yangtze River(NYR) was mainly related to the <Q_1> over the East Asia summer monsoon region:when the <Q_1> over the Philippines through Western Pacific and the south China was weakened(strengthened),it would probably result in the flood(drought) in NYR;and the precipitation on the south side of Yangtze River(SYR)was related to the <Q_1> over the east Asia and Indian summer monsoon region:when the <Q_1> over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened(weakened),and the <Q_1> over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened(strengthened),it will lead to flood(drought) in SYR.展开更多
By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought duri...By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought during the annually first rainy season in south China. Results show that westem Pacific subtropical high and wind anomalies over the northeast of Lake Baikal and central Indian Ocean are important factors. Wind anomalies over the northem India in January and the northwest Pacific in March may be strong prediction signals. Study also shows that rainfall in south China bears a close relation to the geopotential height filed over the northern Pacific in March.展开更多
In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mit...In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.展开更多
Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance...Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.展开更多
Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food securit...Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food security.This study investi-gates the atmospheric and oceanic mechanisms that modulate JJAS rainfall us-ing composite analysis,probability evaluation of the Z-index,and correlation analysis with leading climate drivers,including sea surface temperatures(SSTs),wind circulation,and outgoing longwave radiation(OLR).The results show that 40.3%of JJAS rainfall is normal,29.5%and 30.2%are dry and wet,respectively.Wet years have sharply increased since 1998,showing a shift in the rainfall patterns.Wind circulation analysis shows that 850 hPa westerly and 200 hPa easterly winds occur during wet years,which enhance the transport of moisture and convection,whereas dry years have their wind patterns in re-verse,suppressing rainfall.The correlation of Sea Surface Temperature with rainfall in JJAS has a very significant negative correlation(-0.8)in central and eastern Pacific SSTs,indicating La Niña enhancing rainfall and El Niño deficit it.Conversely,a significant positive correlation(0.8)in the western Pacific modulating the regional SST anomaly Ethiopian rainfall.The Nino 3.4 Index shows a significant negative relationship(-0.5 to-0.8)with Ethiopia’s JJAS rain,especially in the northeast,central,and eastern regions,the key role of the ENSO in rainfall variability.Moreover,the negative OLR anomaly and high RH,promote cloudiness and precipitation,while dry years are distinguished by the higher OLR anomaly and reduced RH,which suppress convection.These results confirm the leading influence of the El Nino-Southern Oscillation(ENSO)in controlling Ethiopian rainfall variability and suggest that monitor-ing of SST structure,particularly the Nino 3.4 Index,might enhance seasonal rainfall prediction and inform the Ethiopian climatic change strategy.Future studies should incorporate high-resolution modeling,improved observations,advanced statistics,and Machine Learning to better comprehend Ethiopia’s cli-mate extremes.展开更多
Drought across Northwest China in late spring has exerted a vital effect on the local climate and agricultural production,and has been alleviated during the past decades.This study explored the influence of the preced...Drought across Northwest China in late spring has exerted a vital effect on the local climate and agricultural production,and has been alleviated during the past decades.This study explored the influence of the preceding Arctic sea ice on the May drought in Northwest China caused by the precipitation deficit.Further analysis indicated that when the Greenland Sea ice concentration is abnormally high during February to April,the dry conditions in Northwest China tend to be alleviated.The increase of sea ice in the Greenland Sea can excite a meridional circulation,which causes sea surface temperature(SST)anomalies in the North Atlantic via the sea-air interaction,manifested as significant warm SST anomalies over the south of Greenland and the subtropical North Atlantic,but negative SST anomalies over the west of the Azores.This abnormal SST pattern maintains to May and triggers a zonal wave train from the North Atlantic through Scandinavia and Central Asia to Northwest China,leading to abnormal cyclones in Northwest China.Consequently,Northwest China experiences a more humid climate than usual.展开更多
Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing p...Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing plants to resist recurrent severe drought stress.However,the underlying mechanisms remain unclear.Here,we subjected wheat plants to drought priming during the vegetative growth stage and to severe drought stress at 10 days after anthesis.We then collected leaf samples at the ends of the drought priming and recovery periods,and at the end of drought stress for transcriptome sequencing in combination with phenotypic and physiological analyses.The drought-primed wheat plants maintained a lower plant temperature,with higher stomatal openness and photosynthesis,thereby resulting in much lower 1,000-grain weight and grain yield losses under the later drought stress than the non-primed plants.Interestingly,416 genes,including 27 transcription factors(e.g.,MYB,NAC,HSF),seemed to be closely related to the improved drought tolerance as indicated by the dynamic transcriptome analysis.Moreover,the candidate genes showed six temporal expression patterns and were significantly enriched in several stress response related pathways,such as plant hormone signal transduction,starch and sucrose metabolism,arginine and proline metabolism,inositol phosphate metabolism,and wax synthesis.These findings provide new insights into the physiological and molecular mechanisms of the long-term effects of early drought priming that can effectively improve drought tolerance in wheat,and may provide potential approaches for addressing the challenges of increasing abiotic stresses and securing food safety under global warming scenarios.展开更多
The chalcone isomerase gene OsCHI,one of the key genes in the flavonoid biosynthesis pathway,plays an important role in rice(Oryza sativa)resistance to abiotic stresses.This study reveals how the chalcone isomerase ge...The chalcone isomerase gene OsCHI,one of the key genes in the flavonoid biosynthesis pathway,plays an important role in rice(Oryza sativa)resistance to abiotic stresses.This study reveals how the chalcone isomerase gene family member OsCHI3 participates in rice responses to drought stress through the regulation of flavonoid biosynthesis.Overexpression of OsCHI3 increased the tolerance of rice to drought stress.In contrast,CRISPR/Cas9-mediated deletion of OsCHI3 reduced the drought tolerance of rice,an effect that is reversed by exogenous ABA treatment.Transcriptomic and physiological biochemical analyses indicated that flavonoids regulated by OsCHI3 not only scavenge reactive oxygen species(ROS)but also increase drought tolerance in rice by stimulating ABA biosynthesis through the regulation of OsNCED1 and OsABA8ox3 expression.These findings demonstrate that OsCHI3 increases drought stress tolerance in rice by activating the antioxidant defense system and the ABA metabolic pathway,providing new clues for drought-resistant rice breeding research.展开更多
This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has ...This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has seen a remarkable run of extreme precipitation events and resulting impacts. Here, we provide an overview of the most notable extreme events of the year, including extreme precipitation and floods, tropical cyclones, and droughts. The characteristics and impacts of these extreme events are summarized, followed by discussion on the physical drivers and the role of global warming.Finally, we also discuss the future prospects in extreme event studies, including impact-based perspectives, challenges in attribution of precipitation extremes, and the existing gap to minimize impacts from climate extremes.展开更多
Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts o...Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.展开更多
Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restric...Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.展开更多
The historicity of China's first state-level government(the Xia Dynasty),during which a Great Flood is claimed to have swept through the core of northern China,remains a well-known yet unresolved issue.Archaeologi...The historicity of China's first state-level government(the Xia Dynasty),during which a Great Flood is claimed to have swept through the core of northern China,remains a well-known yet unresolved issue.Archaeologists hypothesize a connection between the legendary events of the Xia Dynasty and archaeological discoveries in the Central China Plains cultural area,encompassing late Neolithic and Bronze Age cultures such as Henan's Longshan,Xinzhai,Erlitou,and Erligang.The authenticity of these speculations has been challenging to substantiate due to the lack of systematic evidence for the Great Flood in the middle to lower Yellow River(YR)Basin.In this paper,we present high-resolution hydrological environmental proxy data,sedimentological remains,and paleontological evidence from the central North China Plain.Our findings provide isochronous evidence of the termination of a hundred-year-long flood period dated to approximately 2080±216 BC,consistent with the observations from lower YR flood plain and marginal marine sediments.These findings both spatially and temporally overlap with the framework of the Great Flood described in the Chinese classics.The alignment between the geoscientific and archaeological evidence and the information in the Chinese classics provides robust confirmation that the Great Flood occurred in the middle to lower YR region during the late Longshan era.展开更多
The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 k...The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 key-informants were surveyed, including water-well owners, well-digging companies, water-trucking suppliers, agricultural pharmacies, and service offices within local councils. The surveys covered all nine districts in northwestern Syria across the Aleppo and the Idleb governorates. The survey findings reveal significant shifts in water sources, an almost halving in water availability and per capita consumption, and a notable decrease in water quality. Coping mechanisms include random well drilling and reduced hygiene practices. Water pumping stations face challenges with functionality, and there is a shift towards clean energy sources, particularly solar energy. Challenges identified by the survey respondents include drought, fuel costs, and damaged water networks. The study highlights the urgency of addressing the potable water crisis in Northwest Syria and suggests specific interventions to enhance water sustainability and governance.展开更多
MIKE Flood模型在城市洪涝分析管理中已得到广泛应用,软件模块丰富,功能齐全,对城市洪涝风险分析提供了理论依据和技术支持。文章主要根据某建设项目所在排水区域的地形、排水管网、周边河道等基础资料,利用MIKE FLOOD软件进行建模,耦...MIKE Flood模型在城市洪涝分析管理中已得到广泛应用,软件模块丰富,功能齐全,对城市洪涝风险分析提供了理论依据和技术支持。文章主要根据某建设项目所在排水区域的地形、排水管网、周边河道等基础资料,利用MIKE FLOOD软件进行建模,耦合计算区域设计工况下洪涝水位、淹没水深、淹没范围,并提出相应工作建议,为城市防灾减灾工作提供支持。展开更多
In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier clim...In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier climate in the future. Predicting the yield loss due to an anticipated drought is crucial for wheat growers. A reliable way for predicting the drought-induced yield loss is to use a plant physiology-based drought index, such as Agricultural Reference Index for Drought (ARID). Since different wheat cultivars exhibit varying levels of sensitivity to water stress, the impact of drought could be different on the cultivars belonging to different drought sensitivity groups. The objective of this study was to develop the cultivar drought sensitivity (CDS) group-specific, ARID-based models for predicting the drought-induced yield loss of winter wheat in the Llano Estacado region in the southern United States by accounting for the phenological phase-specific sensitivity to drought. For the study, the historical (1947-2021) winter wheat grain yield and daily weather data of two locations in the region (Bushland, TX and Clovis, NM) were used. The logical values of the drought sensitivity parameters of the yield models, especially for the moderately-sensitive and highly-sensitive CDS groups, indicated that the yield models reflected the phenomenon of water stress decreasing the winter wheat yields in this region satisfactorily. The reasonable values of the Nash-Sutcliffe Index (0.65 and 0.72), the Willmott Index (0.88 and 0.92), and the percentage error (23 and 22) for the moderately-sensitive and highly-sensitive CDS groups, respectively, indicated that the yield models for these groups performed reasonably well. These models could be useful for predicting the drought-induced yield losses and scheduling irrigation allocation based on the phenological phase-specific drought sensitivity as influenced by cultivar genotype.展开更多
Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts ...Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.展开更多
Flooding remains one of the most destructive natural disasters,posing significant risks to both human lives and infrastructure.In India,where a large area is susceptible to flood hazards,the importance of accurate flo...Flooding remains one of the most destructive natural disasters,posing significant risks to both human lives and infrastructure.In India,where a large area is susceptible to flood hazards,the importance of accurate flood frequency analysis(FFA)and flood susceptibility mapping cannot be overstated.This study focuses on the Haora River basin in Tripura,a region prone to frequent flooding due to a combination of natural and anthropogenic factors.This study evaluates the suitability of the Log-Pearson Type Ⅲ(LP-Ⅲ)and Gumbel Extreme Value-1(EV-1)distributions for estimating peak discharges and delineates floodsusceptible zones in the Haora River basin,Tripura.Using 40 years of peak discharge data(1984-2023),the LP-Ⅲ distribution was identified as the most appropriate model based on goodness-of-fit tests.Flood susceptibility mapping,integrating 16 thematic layers through the Analytical Hierarchy Process,identified 8%,64%,and 26%of the area as high,moderate,and low susceptibility zones,respectively,with a model success rate of 0.81.The findings highlight the need for improved flood management strategies,such as enhancing river capacity and constructing flood spill channels.These insights are critical for designing targeted flood mitigation measures in the Haora basin and other flood-prone regions.展开更多
基金National Natural Science Foundation of China(41275080)China Meteorological Administration Special Public Welfare Research Fund(GYHY201306022)Open Research Fund Program of Plateau Atmosphere and Environment Key Laboratory of Sichuan Province(PAEKL-2010-C3)
文摘NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007.The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part.As a result,relationships between an atmospheric heating source(hereafter called <Q_1>) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper.The results are shown as follows.The flood/drought to the north of Yangtze River(NYR) was mainly related to the <Q_1> over the East Asia summer monsoon region:when the <Q_1> over the Philippines through Western Pacific and the south China was weakened(strengthened),it would probably result in the flood(drought) in NYR;and the precipitation on the south side of Yangtze River(SYR)was related to the <Q_1> over the east Asia and Indian summer monsoon region:when the <Q_1> over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened(weakened),and the <Q_1> over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened(strengthened),it will lead to flood(drought) in SYR.
基金Natural Science Foundation of China (40275028)Research Fund for the Science of Tropicaland Marine Meteorology
文摘By using the significance test of two-dimensional wind field anomalies and Monte Carlo simulation experiment scheme, the significance features of wind field anomalies are investigated in relation to flood/drought during the annually first rainy season in south China. Results show that westem Pacific subtropical high and wind anomalies over the northeast of Lake Baikal and central Indian Ocean are important factors. Wind anomalies over the northem India in January and the northwest Pacific in March may be strong prediction signals. Study also shows that rainfall in south China bears a close relation to the geopotential height filed over the northern Pacific in March.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3209800)the National Natural Science Foundation of China(Grant No.52279011).
文摘In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.
文摘Rice varieties tolerant to submergence regulate shoot elongation during short-term submergence by expressing the SUB1A gene.In contrast,the deep-rooted DRO1 is effectively expressed under drought conditions to enhance water and nutrient uptake.This study investigates the growth and yield of rice with both SUB1A and DRO1 in the background of IR64,under early-season flooding,and mid-season drought.The study used a randomized complete design with two factors:soil moisture treatments(submergence,drought,and their combination)and genotypes.The genotypes included IR64,and three near-isogenic lines(NILs):NIL-SUB1DRO1,NIL-SUB1,and NIL-DRO1.Complete submergence was imposed for 7 days on 14-day-old seedlings,while drought was imposed on control and submerged plants following a 21-day recovery period from submergence,using 42-day-old plants.Variables were measured before and after treatments(submergence and drought),and at harvest or grain maturity.The stresses negatively affected the genotypes.At harvest,IR64 and NIL-SUB1DRO1 under both stresses showed a significant reduction in tiller numbers,shoot dry weights,and yields compared to their control plants.IR64 exhibited a significant delay in reaching flowering under all stresses.The rice introgression lines showed significant improvements in tolerance to the stresses.The study showed no negative consequences of combining drought and submergence tolerance in rice.
文摘Understanding the major drivers of Ethiopian JJAS rainfall variability is crucial for monitoring climate extremes such as drought and flood events,which have serious implications for lives,livelihoods and food security.This study investi-gates the atmospheric and oceanic mechanisms that modulate JJAS rainfall us-ing composite analysis,probability evaluation of the Z-index,and correlation analysis with leading climate drivers,including sea surface temperatures(SSTs),wind circulation,and outgoing longwave radiation(OLR).The results show that 40.3%of JJAS rainfall is normal,29.5%and 30.2%are dry and wet,respectively.Wet years have sharply increased since 1998,showing a shift in the rainfall patterns.Wind circulation analysis shows that 850 hPa westerly and 200 hPa easterly winds occur during wet years,which enhance the transport of moisture and convection,whereas dry years have their wind patterns in re-verse,suppressing rainfall.The correlation of Sea Surface Temperature with rainfall in JJAS has a very significant negative correlation(-0.8)in central and eastern Pacific SSTs,indicating La Niña enhancing rainfall and El Niño deficit it.Conversely,a significant positive correlation(0.8)in the western Pacific modulating the regional SST anomaly Ethiopian rainfall.The Nino 3.4 Index shows a significant negative relationship(-0.5 to-0.8)with Ethiopia’s JJAS rain,especially in the northeast,central,and eastern regions,the key role of the ENSO in rainfall variability.Moreover,the negative OLR anomaly and high RH,promote cloudiness and precipitation,while dry years are distinguished by the higher OLR anomaly and reduced RH,which suppress convection.These results confirm the leading influence of the El Nino-Southern Oscillation(ENSO)in controlling Ethiopian rainfall variability and suggest that monitor-ing of SST structure,particularly the Nino 3.4 Index,might enhance seasonal rainfall prediction and inform the Ethiopian climatic change strategy.Future studies should incorporate high-resolution modeling,improved observations,advanced statistics,and Machine Learning to better comprehend Ethiopia’s cli-mate extremes.
基金supported by the National Natural Science Foun-dation of China [grant numbers 41991281 and 42005028]。
文摘Drought across Northwest China in late spring has exerted a vital effect on the local climate and agricultural production,and has been alleviated during the past decades.This study explored the influence of the preceding Arctic sea ice on the May drought in Northwest China caused by the precipitation deficit.Further analysis indicated that when the Greenland Sea ice concentration is abnormally high during February to April,the dry conditions in Northwest China tend to be alleviated.The increase of sea ice in the Greenland Sea can excite a meridional circulation,which causes sea surface temperature(SST)anomalies in the North Atlantic via the sea-air interaction,manifested as significant warm SST anomalies over the south of Greenland and the subtropical North Atlantic,but negative SST anomalies over the west of the Azores.This abnormal SST pattern maintains to May and triggers a zonal wave train from the North Atlantic through Scandinavia and Central Asia to Northwest China,leading to abnormal cyclones in Northwest China.Consequently,Northwest China experiences a more humid climate than usual.
基金supported by the projects of the National Key Research and Development Program of China(2023YFD2300202)the Natural Science Foundation of Jiangsu Province,China(BK20241543)+5 种基金the National Natural Science Foundation of China(32272213,32030076,U1803235,and 32021004)the Fundamental Research Funds for the Central Universities,China(XUEKEN2023013)the Jiangsu Innovation Support Program for International Science and Technology Cooperation Project,China(BZ2023049)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(22)1006)the China Agriculture Research System(CARS-03)the Jiangsu Collaborative Innovation Center for Modern Crop Production,China(JCIC-MCP)。
文摘Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing plants to resist recurrent severe drought stress.However,the underlying mechanisms remain unclear.Here,we subjected wheat plants to drought priming during the vegetative growth stage and to severe drought stress at 10 days after anthesis.We then collected leaf samples at the ends of the drought priming and recovery periods,and at the end of drought stress for transcriptome sequencing in combination with phenotypic and physiological analyses.The drought-primed wheat plants maintained a lower plant temperature,with higher stomatal openness and photosynthesis,thereby resulting in much lower 1,000-grain weight and grain yield losses under the later drought stress than the non-primed plants.Interestingly,416 genes,including 27 transcription factors(e.g.,MYB,NAC,HSF),seemed to be closely related to the improved drought tolerance as indicated by the dynamic transcriptome analysis.Moreover,the candidate genes showed six temporal expression patterns and were significantly enriched in several stress response related pathways,such as plant hormone signal transduction,starch and sucrose metabolism,arginine and proline metabolism,inositol phosphate metabolism,and wax synthesis.These findings provide new insights into the physiological and molecular mechanisms of the long-term effects of early drought priming that can effectively improve drought tolerance in wheat,and may provide potential approaches for addressing the challenges of increasing abiotic stresses and securing food safety under global warming scenarios.
基金supported by Science and Technology Innovation Program of Hunan province(2024NK1010,2023NK1010,2023ZJ1080)the National Natural Science Foundation of China(U21A20208).
文摘The chalcone isomerase gene OsCHI,one of the key genes in the flavonoid biosynthesis pathway,plays an important role in rice(Oryza sativa)resistance to abiotic stresses.This study reveals how the chalcone isomerase gene family member OsCHI3 participates in rice responses to drought stress through the regulation of flavonoid biosynthesis.Overexpression of OsCHI3 increased the tolerance of rice to drought stress.In contrast,CRISPR/Cas9-mediated deletion of OsCHI3 reduced the drought tolerance of rice,an effect that is reversed by exogenous ABA treatment.Transcriptomic and physiological biochemical analyses indicated that flavonoids regulated by OsCHI3 not only scavenge reactive oxygen species(ROS)but also increase drought tolerance in rice by stimulating ABA biosynthesis through the regulation of OsNCED1 and OsABA8ox3 expression.These findings demonstrate that OsCHI3 increases drought stress tolerance in rice by activating the antioxidant defense system and the ABA metabolic pathway,providing new clues for drought-resistant rice breeding research.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos.42422502 and 42275038)the China Meteorological Administration Climate Change Special Program (Grant No.QBZ202306)funded by the Met Office Climate Science for Service Partnership (CSSP) China project under the International Science Partnerships Fund (ISPF)。
文摘This past year, 2024, is on track to be the warmest year, joining 2023 as the two hottest years on record. With the exceptional heat, weather and climate extremes were common across the world. In particular, 2024 has seen a remarkable run of extreme precipitation events and resulting impacts. Here, we provide an overview of the most notable extreme events of the year, including extreme precipitation and floods, tropical cyclones, and droughts. The characteristics and impacts of these extreme events are summarized, followed by discussion on the physical drivers and the role of global warming.Finally, we also discuss the future prospects in extreme event studies, including impact-based perspectives, challenges in attribution of precipitation extremes, and the existing gap to minimize impacts from climate extremes.
基金funded by the National Key Research and Development Plan of China(No.2022YFE0127900)the National Natural Science Foundation of China(Nos.32071558,32171559)+2 种基金the Natural Science Foundation Key Project of Inner Mongolia Autonomous Region,China(No.2023ZD23)the Hulunbuir Science and Technology Plan Project(No.SF2022001)the Fundamental Research Funds of CAF(CAFYBB2023ZA002).
文摘Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.
基金supported by the National Key Research and Development Program of China(2021YFD1200703 and 2022YFF1001602)the National Science Foundation of China(32272024 and 32171940)+2 种基金the Pinduoduo-China Agricultural University Research Fund(PC2023B01001)the Chinese Universities Scientific Fund(2022TC142)the 2115 Talent Development Program of China Agricultural University。
文摘Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.
基金Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDB26000000National Natural Science Foundation of China,No.41888101,No.42072209Geological Survey Projects of China,No.DD20189629,No.DD20190370。
文摘The historicity of China's first state-level government(the Xia Dynasty),during which a Great Flood is claimed to have swept through the core of northern China,remains a well-known yet unresolved issue.Archaeologists hypothesize a connection between the legendary events of the Xia Dynasty and archaeological discoveries in the Central China Plains cultural area,encompassing late Neolithic and Bronze Age cultures such as Henan's Longshan,Xinzhai,Erlitou,and Erligang.The authenticity of these speculations has been challenging to substantiate due to the lack of systematic evidence for the Great Flood in the middle to lower Yellow River(YR)Basin.In this paper,we present high-resolution hydrological environmental proxy data,sedimentological remains,and paleontological evidence from the central North China Plain.Our findings provide isochronous evidence of the termination of a hundred-year-long flood period dated to approximately 2080±216 BC,consistent with the observations from lower YR flood plain and marginal marine sediments.These findings both spatially and temporally overlap with the framework of the Great Flood described in the Chinese classics.The alignment between the geoscientific and archaeological evidence and the information in the Chinese classics provides robust confirmation that the Great Flood occurred in the middle to lower YR region during the late Longshan era.
文摘The study investigates the impact of the Syrian crisis and the recent drought on the potable water situation in Northwest Syria, comparing various aspects of water availability and quality before and after 2011. 380 key-informants were surveyed, including water-well owners, well-digging companies, water-trucking suppliers, agricultural pharmacies, and service offices within local councils. The surveys covered all nine districts in northwestern Syria across the Aleppo and the Idleb governorates. The survey findings reveal significant shifts in water sources, an almost halving in water availability and per capita consumption, and a notable decrease in water quality. Coping mechanisms include random well drilling and reduced hygiene practices. Water pumping stations face challenges with functionality, and there is a shift towards clean energy sources, particularly solar energy. Challenges identified by the survey respondents include drought, fuel costs, and damaged water networks. The study highlights the urgency of addressing the potable water crisis in Northwest Syria and suggests specific interventions to enhance water sustainability and governance.
文摘In most agricultural areas in the semi-arid region of the southern United States, wheat (Triticum aestivum L.) production is a primary economic activity. This region is drought-prone and projected to have a drier climate in the future. Predicting the yield loss due to an anticipated drought is crucial for wheat growers. A reliable way for predicting the drought-induced yield loss is to use a plant physiology-based drought index, such as Agricultural Reference Index for Drought (ARID). Since different wheat cultivars exhibit varying levels of sensitivity to water stress, the impact of drought could be different on the cultivars belonging to different drought sensitivity groups. The objective of this study was to develop the cultivar drought sensitivity (CDS) group-specific, ARID-based models for predicting the drought-induced yield loss of winter wheat in the Llano Estacado region in the southern United States by accounting for the phenological phase-specific sensitivity to drought. For the study, the historical (1947-2021) winter wheat grain yield and daily weather data of two locations in the region (Bushland, TX and Clovis, NM) were used. The logical values of the drought sensitivity parameters of the yield models, especially for the moderately-sensitive and highly-sensitive CDS groups, indicated that the yield models reflected the phenomenon of water stress decreasing the winter wheat yields in this region satisfactorily. The reasonable values of the Nash-Sutcliffe Index (0.65 and 0.72), the Willmott Index (0.88 and 0.92), and the percentage error (23 and 22) for the moderately-sensitive and highly-sensitive CDS groups, respectively, indicated that the yield models for these groups performed reasonably well. These models could be useful for predicting the drought-induced yield losses and scheduling irrigation allocation based on the phenological phase-specific drought sensitivity as influenced by cultivar genotype.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3006505)the Fundamental Research Funds for the Central Universities of China(Grant No.B240203007)the National Key Laboratory of Water Disaster Prevention(Grant No.524015222)。
文摘Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.
文摘Flooding remains one of the most destructive natural disasters,posing significant risks to both human lives and infrastructure.In India,where a large area is susceptible to flood hazards,the importance of accurate flood frequency analysis(FFA)and flood susceptibility mapping cannot be overstated.This study focuses on the Haora River basin in Tripura,a region prone to frequent flooding due to a combination of natural and anthropogenic factors.This study evaluates the suitability of the Log-Pearson Type Ⅲ(LP-Ⅲ)and Gumbel Extreme Value-1(EV-1)distributions for estimating peak discharges and delineates floodsusceptible zones in the Haora River basin,Tripura.Using 40 years of peak discharge data(1984-2023),the LP-Ⅲ distribution was identified as the most appropriate model based on goodness-of-fit tests.Flood susceptibility mapping,integrating 16 thematic layers through the Analytical Hierarchy Process,identified 8%,64%,and 26%of the area as high,moderate,and low susceptibility zones,respectively,with a model success rate of 0.81.The findings highlight the need for improved flood management strategies,such as enhancing river capacity and constructing flood spill channels.These insights are critical for designing targeted flood mitigation measures in the Haora basin and other flood-prone regions.
