Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Tempor...Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Temporal trends and spatial distribution patterns of extreme temperature and precipitation in this area were then analyzed using 12 extreme temperature and 7 extreme precipitation indices. The following results were obtained. 1) Over the past 50 years, extreme cold indices, excepting the monthly maximum temperature minimum value and monthly extreme minimum temperature, showed slight decreasing trends. These indices include the maximum number of consecutive frost days, icy days, cold-nighttime days, and cold-daytime days. 2) Extreme warm events generally showed significant increasing trends (P < 0.01), including the indices of summertime days, warm-nighttime days, warm-daytime days, monthly extreme maximum temperature, and monthly minimum temperature maximum value. 3) The spatial distributions of threshold values of extreme warm and cold events showed notable regional differences. A reducing trend of extreme cold events and an increase in extreme warm events has occurred mainly in northern Xinjiang. 4) For the past 50 years, six extreme precipitation indices, aside from consecutive dry days, showed significant increasing trends in Xinjiang (P < 0.05) and notable differences in spatial distribution. The increase in extreme precipitation events was more rapid at northern than at southern sites. Extreme precipitation intensity was greater in mountainous areas, and precipitation frequency increased in the plain region. 5) Factor analysis revealed good correlations among extreme temperature indices, excepting extreme temperature days.展开更多
Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology...Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology observation data to investigate the spatial distributions and temporal trends of agro-climatic resources and extreme climate events during the growing season for soybean in Northeast China(NEC).The results showed that during the soybean growing season,the thermal time increased while both the effective precipitation and photosynthetically active radiation(PAR)decreased.Within the growing season,the thermal time increased by 44.0°C day decade–1 during the vegetative stage but decreased by 16.5°C day decade–1 during the reproductive stage;the effective precipitation increased by 1.8 mm decade–1 during the vegetative stage but decreased by 7.3 mm decade–1 during the reproductive stage;PAR decreased by 6.5 and 11.9 MJ m–2 decade–1 during the vegetative and reproductive stages.The frequency of extreme cold days showed a decreasing trend during the four study phases of sowing to emergence,sowing–flowering,15 days before flowering–flowering,and pod to physiological maturity.During the soybean growing season,the frequency of extreme heat days and the maximum number of consecutive dry days(CDD)increased,and the maximum number of consecutive wet days(CWD)and heavy precipitation days decreased.The results of this study could be used in selecting optimal management in soybean production in order to take advantage of beneficial climatic elements.展开更多
To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitatio...To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitation from six meteorological stations in the Manas River basin as well as daily runoff data from the Kensiwate hydrologic stations during 1960-2010. By adopting the threshold value of extreme climatic events defined by ET ALDDMI and with the aid of nonparametric statistical tests, Pearson III methods, and others, the effect of extreme climatic events on extreme runoff in the past 50 years in the Manas River basin, Xinjiang, was analyzed. The results showed that in the past 50 years, 1) extreme warming events (annual extreme maximum temperature, warm-day and warm-night index) have risen significantly (P < 0.05). Among these the warm-day and warm-night indices decreased abruptly in 2001 and 1996, respectively. With respect to extreme cold events (annual extreme minimum temperature, cold-day and cold-night indices), the extreme minimum temperature was high after 1976, and the cold-day index weakened significantly, similar to the cold-night index. 2) Except for the continuous drought days (CDD), the other five indices of extreme precipitation events appeared to trend upward, with an abrupt change around 1993. 3) Flood events in 1990, mostly in summer, accounted for 42.9% of the total number of floods since 1960. Floods increased mainly because extremely high summer temperatures increased snowmelt, increasing inflow to the rivers, which combined with more precipitation to cause the increase in summer peak flood discharge.展开更多
Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene–Eocene of the Jianghan Basin.However,the basin history is still unclear concerning the potash enriching conditions and...Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene–Eocene of the Jianghan Basin.However,the basin history is still unclear concerning the potash enriching conditions and mechanism.The Well SKD1 is the first exploration well drilled in the Paleogene of Jianghan Basin with continuous coring,which was implemented in the展开更多
The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has be...The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has been observed in the Antarctic Peninsula and West Antarctica since 1979,with some parts of East Antarctica also experiencing warming.In 2022,the regional average temperature in Antarctica based on observational data was close to the long-term average(1991-2020).The Arctic,on the other hand,has experienced a warming trend at a rate of 0.63℃per decade from 1979 to 2022 based on CRA-40,which is 3.7 times the global mean during the same period(0.17℃per decade).In 2022,the overall temperature in the Arctic,using station data,was 1.10℃above the long-term average(1991-2020).In recent years,both the Antarctic and Arctic regions have witnessed an increase in the frequency and intensity of extreme weather events.In 2022,based on the sea ice extent from National Snow and Ice Data Center,USA,Antarctic sea ice reached its lowest extent on record since 1979,and on 18 March,the most rapid surface warming event ever recorded on Earth occurred in the Antarctic,with a temperature increase of 49℃within 3 d.This report has been integrated into China's National Climate Change Bulletin system,to contribute to raising public awareness of polar climate change and providing valuable scientific references to address climate change.展开更多
Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and ...Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and Semi-Arid Lands (ASALs). A small change in the mean climate condition can cause large changes in these production systems. There is a paucity of information on trends in climate and climate extremes in the country. However, a joint World Meteorological Commission for Climatology/World Climate Research Programme (WCPRP) project on climate Variability and Predictability (WMO CCl/CLIVAR) Expert Team (ET) on Climate Change Detection, Monitoring and Indices has defined 27 core climate indices mainly focusing on extreme events which can be derived through the use of RClimDex Software. In this study, therefore, the RClimDex software has been used to derive climate extreme indices for five stations in the ASALs of South-Eastern Kenya based on climate data for the period 1961 to 2009. The objective was to examine trends in these extremes to aid agricultural planning and practice. These indices have shown decreasing trends in annual rainfall, rainfall intensity and consecutive wet days but increasing trends in consecutive dry days. Steady warming patterns were evident in both the maximum and minimum temperature indices. This paper concludes that indeed significant changes in climate extremes are apparent in the ASALs of the country and recommends a re-thinking of planning and practice of rain-fed agriculture in the ASALs of South-Eastern Kenya.展开更多
China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity...China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity during the first half of the season in the western North Pacific(WNP).Sea surface temperature changes in the Pacific,Indian,and Atlantic Oceans all contributed to the heavy rainfall in China,but the Atlantic and Indian Oceans seem to have played dominant roles.Enhancement and movement of the Siberian High caused a wavier pattern in the jet stream that allowed cold polar air to reach southward,inducing cold surges in China.Large vertical wind shear and low humidity in the WNP were responsible for fewer typhoons in the first half of the typhoon season.Although it is known that global warming can increase the frequency of extreme weather and climate events,its influences on individual events still need to be quantified.Additionally,the extreme cold surge during 16–18 February 2021 in the United States shares similar mechanisms with the winter 2020/21 extreme cold surges in China.展开更多
An update on the climate norms each decade is recommended by the World Meteorological Organization(WMO)partly to keep pace with conditions as climate changes over time.In accordance with such update,this study documen...An update on the climate norms each decade is recommended by the World Meteorological Organization(WMO)partly to keep pace with conditions as climate changes over time.In accordance with such update,this study documents the features of the new climate normal defined for 1991-2020 and its impacts on climate monitoring and prediction in China.With on-site observation and model prediction datasets,our analysis reveals that the new normal of national average precipitation of China during winter and summer is respectively 3.0 and 10.8 mm higher than that of the period 1981-2010.As a result,precipitation observations during 1961-2020 consistently fall below the new normal.The adjustment of thresholds for precipitation extremes with new climate normals results in a decrease of extreme precipitation occurrence by 0.2-0.8 d on average over the winter and summer seasons during 1961-2020.Meanwhile,the application of new climate normals induces more pronounced negative temperature anomalies across most areas of China.The adjustments of extreme temperature thresholds have led to an increased occurrence of extremely cold days by 1-2 d on average over 1961-2020,while the frequency of extremely hot days decreases by more than 1.4 d.Furthermore,it is implied that with the development of global warming,the baselines for temperature and precipitation are rising.The application of the new climate normal may result in the omission of relative threshold based extreme events,promoting increased focus on climate risk reduction studies.Additionally,the average anomaly sign consistency rates(Pcs)of precipitation and temperature anomaly predictions,relative to the new normal and produced by the Beijing Climate Center,are consistently lower than those relative to the old normal.This decrease in Pcs implies new challenges for climate prediction,especially for temperature prediction.展开更多
Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nation...Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nationally effective responses to extreme climate events.However,related studies are still negligible,and the assessment urgently needs to be validated with actual health data after extreme weather events.We established health V&A indices through literature review and factor analyses.Then,we separately mapped the spatial distribution of flood exposure,social and public health sensitivity,and adaptive capacity before the 2016 flood in Anhui province and compared it with post-flood diarrhea risks by using the geographic information system method to assess health vulnerability.Finally,we validated the indices by exploring the relationship between health V&A indices and post-flood diarrhea risks by using the quantile regression model.Results revealed that health V&A can be framed and categorized as key components of exposure,sensitivity,and adaptive capacity.The remarkable differences in the spatial distribution of health vulnerability were generally consistent with the demographic sensitivity,geographic flooding exposure,and post-flood diarrhea risks in Anhui.In addition,health V&A indices exerted significant positive impacts on infectious diarrhea post-flooding at all quantiles and were significant across different percentiles.Moreover,the impacts of flood exposure on total infectious diarrhea were high and continuous,whereas the impacts of sensitivity were not obvious in the flood's early stage(Coeff=0.643;p<0.001)but high in the flood's middle(Coeff=0.997;p<0.001)and late stages(Coeff=0.975;p<0.001).However,the impacts of adaptive capacity were heterogeneous and high in the flood's early stage(Coeff=0.665;p<0.001 at the 25th percentile)and late stage(Coeff=1.296;p<0.001 at the 75th percentile)but were insignificant at the 50th percentile.This study contributed validated three-layered health V&A indices with 30 indicators and identified that the impacts of the key components on post-flood waterborne-disease risks are heterogeneous.For instance,local public health sensitivity and adaptive capacity are insufficient to reduce these risks in the long run.This study could be used to project population health risks after extreme weather events and thereby contributes to local government planning of health adaptation.展开更多
Background:Transitional economies in Southeast Asia—a distinct group of developing countries—have experienced rapid urbanization in the past several decades due to the economic transition that fundamentally changed ...Background:Transitional economies in Southeast Asia—a distinct group of developing countries—have experienced rapid urbanization in the past several decades due to the economic transition that fundamentally changed the function of their economies,societies and the environment.Myanmar,one of the least developed transitional economies in Southeast Asia,increased urbanization substantially from 25%in 1990 to 31%in 2019.However,major knowledge gaps exist in understanding the changes in urban land use and land cover and environment and their drivers in its cities.Methods:We studied Yangon,the largest city in Myanmar,for the urbanization,environmental changes,and the underlying driving forces in a radically transitioned economy in the developing world.Based on satellite imagery and historic land use maps,we quantified the expansion of urban built-up land and constructed the land conversion matrix from 1990 through 2020.We also used three air pollutants to illustrate the changes in environmental conditions.We analyzed the coupled dynamics among urbanization,economic development,and environmental changes.Through conducting a workshop with 20 local experts,we further analyzed the influence of human systems and natural systems on Yangon’s urbanization and sustainability.Results:The city of Yangon expanded urban built-up land rapidly from 1990 to 2000,slowed down from 2000 to 2010,but gained momentum again from 2010 to 2020,with most newly added urban built-up land appearing to be converted from farmland and green land in both 1990–2000 and 2010–2020.Furthermore,the air pollutant concen-tration of CO decreased,but that of NO_(2)and PM_(2.5)increased in recent years.A positive correlation exists between population and economic development and the concentration of PM_(2.5)is highly associated with population,the economy,and the number of vehicles.Finally,the expert panel also identified other potential drivers for urbanization,including the extreme climate event of Cyclone Nargis,capital relocation,and globalization.Conclusions:Our research highlights the dramatic expansion of urban land and degradation of urban environment measured by air pollutants and interdependent changes between urbanization,economic development,and environmental changes.展开更多
General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic ev...General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic events,due to its unique active tectonic environment and climatic complexity.Although these two major natural disasters have caused great damage to human society,it remains unclear whether and how they affect Chinese dynasty alternation on decadal(emperor)timescales.Based on detailed comparisons between abrupt climatic changes,catastrophic seismic activities,and the history of Chinese dynasty alternation from 1000–2000 AD,we conclude that on decadal timescales,extreme drought(and/or flood)events could indeed significantly reduce agricultural production,cause severe food shortages and famine,and result in increases in population exile,rising food prices and inflation,and insufficient supplies for military defense,which could exceed social resilience and eventually lead to financial risks and social upheavals of the dynasties.In addition,catastrophic seismic events in the densely populated,agricultural areas of China,including the 1303 surface wave magnitude(M_(s))8.0 Hongtong earthquake,the 1556 M_(s)8.25Huaxian earthquake and the 1920 M_(s)8.5 Haiyuan earthquake,caused more than 200,000casualties and millions of victims to live in exile which was almost equivalent to the order of magnitude of those extreme climatic events-induced refugees.The secondary geological hazards related to the earthquakes(e.g.,extensive landslides and soil erosion),which could last for decades,caused more casualties and reduced food production.Furthermore,great plague spread caused by the casualties could significantly increase psychological panic among the survivors,resulting in social instability.Therefore,catastrophic seismic events could also accelerate the collapse of the dynasties(e.g.,the Ming dynasty)without immediate mitigation measures.This study indicates that catastrophic seismic activities,as well as extreme climatic events,could have great effects on the social structures and thus on the Chinese dynasty alternation on decadal timescales,which highlights the far-reaching implications of geological hazard research.展开更多
文摘Daily maximum/minimum temperature and precipitation data from 35 weather stations in Xinjiang during 1961-2010 were examined using kriging spatial analysis, linear tendency estimation, and correlation analysis. Temporal trends and spatial distribution patterns of extreme temperature and precipitation in this area were then analyzed using 12 extreme temperature and 7 extreme precipitation indices. The following results were obtained. 1) Over the past 50 years, extreme cold indices, excepting the monthly maximum temperature minimum value and monthly extreme minimum temperature, showed slight decreasing trends. These indices include the maximum number of consecutive frost days, icy days, cold-nighttime days, and cold-daytime days. 2) Extreme warm events generally showed significant increasing trends (P < 0.01), including the indices of summertime days, warm-nighttime days, warm-daytime days, monthly extreme maximum temperature, and monthly minimum temperature maximum value. 3) The spatial distributions of threshold values of extreme warm and cold events showed notable regional differences. A reducing trend of extreme cold events and an increase in extreme warm events has occurred mainly in northern Xinjiang. 4) For the past 50 years, six extreme precipitation indices, aside from consecutive dry days, showed significant increasing trends in Xinjiang (P < 0.05) and notable differences in spatial distribution. The increase in extreme precipitation events was more rapid at northern than at southern sites. Extreme precipitation intensity was greater in mountainous areas, and precipitation frequency increased in the plain region. 5) Factor analysis revealed good correlations among extreme temperature indices, excepting extreme temperature days.
基金Supported by the National Key Research and Development Program of China(2019YFA0607402)。
文摘Soybean is an important oil crop.Agro-climatic resources and extreme climate events during the growing season directly affect the crop growth and grain yield.In this study,we used historical climate data and phenology observation data to investigate the spatial distributions and temporal trends of agro-climatic resources and extreme climate events during the growing season for soybean in Northeast China(NEC).The results showed that during the soybean growing season,the thermal time increased while both the effective precipitation and photosynthetically active radiation(PAR)decreased.Within the growing season,the thermal time increased by 44.0°C day decade–1 during the vegetative stage but decreased by 16.5°C day decade–1 during the reproductive stage;the effective precipitation increased by 1.8 mm decade–1 during the vegetative stage but decreased by 7.3 mm decade–1 during the reproductive stage;PAR decreased by 6.5 and 11.9 MJ m–2 decade–1 during the vegetative and reproductive stages.The frequency of extreme cold days showed a decreasing trend during the four study phases of sowing to emergence,sowing–flowering,15 days before flowering–flowering,and pod to physiological maturity.During the soybean growing season,the frequency of extreme heat days and the maximum number of consecutive dry days(CDD)increased,and the maximum number of consecutive wet days(CWD)and heavy precipitation days decreased.The results of this study could be used in selecting optimal management in soybean production in order to take advantage of beneficial climatic elements.
文摘To analyze extreme climatic change features and effects on runoff in the Manas River basin, Xinjiang, data were collected including daily mean temperature, daily highest and lowest temperatures, and daily precipitation from six meteorological stations in the Manas River basin as well as daily runoff data from the Kensiwate hydrologic stations during 1960-2010. By adopting the threshold value of extreme climatic events defined by ET ALDDMI and with the aid of nonparametric statistical tests, Pearson III methods, and others, the effect of extreme climatic events on extreme runoff in the past 50 years in the Manas River basin, Xinjiang, was analyzed. The results showed that in the past 50 years, 1) extreme warming events (annual extreme maximum temperature, warm-day and warm-night index) have risen significantly (P < 0.05). Among these the warm-day and warm-night indices decreased abruptly in 2001 and 1996, respectively. With respect to extreme cold events (annual extreme minimum temperature, cold-day and cold-night indices), the extreme minimum temperature was high after 1976, and the cold-day index weakened significantly, similar to the cold-night index. 2) Except for the continuous drought days (CDD), the other five indices of extreme precipitation events appeared to trend upward, with an abrupt change around 1993. 3) Flood events in 1990, mostly in summer, accounted for 42.9% of the total number of floods since 1960. Floods increased mainly because extremely high summer temperatures increased snowmelt, increasing inflow to the rivers, which combined with more precipitation to cause the increase in summer peak flood discharge.
基金the National Science Foundation of China(Grants No.41502089,41302059 and 41202059)for their financial support
文摘Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene–Eocene of the Jianghan Basin.However,the basin history is still unclear concerning the potash enriching conditions and mechanism.The Well SKD1 is the first exploration well drilled in the Paleogene of Jianghan Basin with continuous coring,which was implemented in the
基金supported by the National Science Foundation of China (Grant no.42122047)the Basic Fund of the Chinese Academy of Meteorological Sciences (Grant nos.2021Z006 and 2023Z025)。
文摘The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has been observed in the Antarctic Peninsula and West Antarctica since 1979,with some parts of East Antarctica also experiencing warming.In 2022,the regional average temperature in Antarctica based on observational data was close to the long-term average(1991-2020).The Arctic,on the other hand,has experienced a warming trend at a rate of 0.63℃per decade from 1979 to 2022 based on CRA-40,which is 3.7 times the global mean during the same period(0.17℃per decade).In 2022,the overall temperature in the Arctic,using station data,was 1.10℃above the long-term average(1991-2020).In recent years,both the Antarctic and Arctic regions have witnessed an increase in the frequency and intensity of extreme weather events.In 2022,based on the sea ice extent from National Snow and Ice Data Center,USA,Antarctic sea ice reached its lowest extent on record since 1979,and on 18 March,the most rapid surface warming event ever recorded on Earth occurred in the Antarctic,with a temperature increase of 49℃within 3 d.This report has been integrated into China's National Climate Change Bulletin system,to contribute to raising public awareness of polar climate change and providing valuable scientific references to address climate change.
文摘Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and Semi-Arid Lands (ASALs). A small change in the mean climate condition can cause large changes in these production systems. There is a paucity of information on trends in climate and climate extremes in the country. However, a joint World Meteorological Commission for Climatology/World Climate Research Programme (WCPRP) project on climate Variability and Predictability (WMO CCl/CLIVAR) Expert Team (ET) on Climate Change Detection, Monitoring and Indices has defined 27 core climate indices mainly focusing on extreme events which can be derived through the use of RClimDex Software. In this study, therefore, the RClimDex software has been used to derive climate extreme indices for five stations in the ASALs of South-Eastern Kenya based on climate data for the period 1961 to 2009. The objective was to examine trends in these extremes to aid agricultural planning and practice. These indices have shown decreasing trends in annual rainfall, rainfall intensity and consecutive wet days but increasing trends in consecutive dry days. Steady warming patterns were evident in both the maximum and minimum temperature indices. This paper concludes that indeed significant changes in climate extremes are apparent in the ASALs of the country and recommends a re-thinking of planning and practice of rain-fed agriculture in the ASALs of South-Eastern Kenya.
基金the National Natural Science Foundation of China(Grant No.41731173)the National Key R&D Program of China(Grant No.2019YFA0606701)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB42000000 and XDA20060502)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.GML2019ZD0306)the Innovation Academy of South China Sea Ecology and Environmental Engineering,the Chinese Academy of Sciences(Grant No.ISEE2018PY06)。
文摘China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity during the first half of the season in the western North Pacific(WNP).Sea surface temperature changes in the Pacific,Indian,and Atlantic Oceans all contributed to the heavy rainfall in China,but the Atlantic and Indian Oceans seem to have played dominant roles.Enhancement and movement of the Siberian High caused a wavier pattern in the jet stream that allowed cold polar air to reach southward,inducing cold surges in China.Large vertical wind shear and low humidity in the WNP were responsible for fewer typhoons in the first half of the typhoon season.Although it is known that global warming can increase the frequency of extreme weather and climate events,its influences on individual events still need to be quantified.Additionally,the extreme cold surge during 16–18 February 2021 in the United States shares similar mechanisms with the winter 2020/21 extreme cold surges in China.
基金supported by the National Natural Science Foundation of China Project (42130610,42075057,41875100,and 42275050)the National Key Research and Development Program of China (2022YFE0136000)the Innovative Team of the Intelligent Forecast of the Extended Range Important Weather Process (Hebei Meteorological Bureau official letter[2022]14).
文摘An update on the climate norms each decade is recommended by the World Meteorological Organization(WMO)partly to keep pace with conditions as climate changes over time.In accordance with such update,this study documents the features of the new climate normal defined for 1991-2020 and its impacts on climate monitoring and prediction in China.With on-site observation and model prediction datasets,our analysis reveals that the new normal of national average precipitation of China during winter and summer is respectively 3.0 and 10.8 mm higher than that of the period 1981-2010.As a result,precipitation observations during 1961-2020 consistently fall below the new normal.The adjustment of thresholds for precipitation extremes with new climate normals results in a decrease of extreme precipitation occurrence by 0.2-0.8 d on average over the winter and summer seasons during 1961-2020.Meanwhile,the application of new climate normals induces more pronounced negative temperature anomalies across most areas of China.The adjustments of extreme temperature thresholds have led to an increased occurrence of extremely cold days by 1-2 d on average over 1961-2020,while the frequency of extremely hot days decreases by more than 1.4 d.Furthermore,it is implied that with the development of global warming,the baselines for temperature and precipitation are rising.The application of the new climate normal may result in the omission of relative threshold based extreme events,promoting increased focus on climate risk reduction studies.Additionally,the average anomaly sign consistency rates(Pcs)of precipitation and temperature anomaly predictions,relative to the new normal and produced by the Beijing Climate Center,are consistently lower than those relative to the old normal.This decrease in Pcs implies new challenges for climate prediction,especially for temperature prediction.
基金This study was supported by grants from the National Natural Science Foundation of China(71774179)the National Key R&D Program of China(2018YFA0606200)+1 种基金National Natural Science Foundation of China(71804205)the Government Reform and Construction of Key Bases of Ministry of Education(16JJD630011).
文摘Climate change could intensify extreme weather events,such as flooding,which amplifies the public health threat of waterborne diseases.Thus,assessing health vulnerability and adaptation(V&A)could facilitate nationally effective responses to extreme climate events.However,related studies are still negligible,and the assessment urgently needs to be validated with actual health data after extreme weather events.We established health V&A indices through literature review and factor analyses.Then,we separately mapped the spatial distribution of flood exposure,social and public health sensitivity,and adaptive capacity before the 2016 flood in Anhui province and compared it with post-flood diarrhea risks by using the geographic information system method to assess health vulnerability.Finally,we validated the indices by exploring the relationship between health V&A indices and post-flood diarrhea risks by using the quantile regression model.Results revealed that health V&A can be framed and categorized as key components of exposure,sensitivity,and adaptive capacity.The remarkable differences in the spatial distribution of health vulnerability were generally consistent with the demographic sensitivity,geographic flooding exposure,and post-flood diarrhea risks in Anhui.In addition,health V&A indices exerted significant positive impacts on infectious diarrhea post-flooding at all quantiles and were significant across different percentiles.Moreover,the impacts of flood exposure on total infectious diarrhea were high and continuous,whereas the impacts of sensitivity were not obvious in the flood's early stage(Coeff=0.643;p<0.001)but high in the flood's middle(Coeff=0.997;p<0.001)and late stages(Coeff=0.975;p<0.001).However,the impacts of adaptive capacity were heterogeneous and high in the flood's early stage(Coeff=0.665;p<0.001 at the 25th percentile)and late stage(Coeff=1.296;p<0.001 at the 75th percentile)but were insignificant at the 50th percentile.This study contributed validated three-layered health V&A indices with 30 indicators and identified that the impacts of the key components on post-flood waterborne-disease risks are heterogeneous.For instance,local public health sensitivity and adaptive capacity are insufficient to reduce these risks in the long run.This study could be used to project population health risks after extreme weather events and thereby contributes to local government planning of health adaptation.
基金supported by the National Aeronautics and Space Administration(NASA)(Grant numbers:NNX15AD51G,80NSSC20K0740).
文摘Background:Transitional economies in Southeast Asia—a distinct group of developing countries—have experienced rapid urbanization in the past several decades due to the economic transition that fundamentally changed the function of their economies,societies and the environment.Myanmar,one of the least developed transitional economies in Southeast Asia,increased urbanization substantially from 25%in 1990 to 31%in 2019.However,major knowledge gaps exist in understanding the changes in urban land use and land cover and environment and their drivers in its cities.Methods:We studied Yangon,the largest city in Myanmar,for the urbanization,environmental changes,and the underlying driving forces in a radically transitioned economy in the developing world.Based on satellite imagery and historic land use maps,we quantified the expansion of urban built-up land and constructed the land conversion matrix from 1990 through 2020.We also used three air pollutants to illustrate the changes in environmental conditions.We analyzed the coupled dynamics among urbanization,economic development,and environmental changes.Through conducting a workshop with 20 local experts,we further analyzed the influence of human systems and natural systems on Yangon’s urbanization and sustainability.Results:The city of Yangon expanded urban built-up land rapidly from 1990 to 2000,slowed down from 2000 to 2010,but gained momentum again from 2010 to 2020,with most newly added urban built-up land appearing to be converted from farmland and green land in both 1990–2000 and 2010–2020.Furthermore,the air pollutant concen-tration of CO decreased,but that of NO_(2)and PM_(2.5)increased in recent years.A positive correlation exists between population and economic development and the concentration of PM_(2.5)is highly associated with population,the economy,and the number of vehicles.Finally,the expert panel also identified other potential drivers for urbanization,including the extreme climate event of Cyclone Nargis,capital relocation,and globalization.Conclusions:Our research highlights the dramatic expansion of urban land and degradation of urban environment measured by air pollutants and interdependent changes between urbanization,economic development,and environmental changes.
基金National Nonprofit Fundamental Research Grant of China,Institute of Geology,China Earthquake Administration,No.IGCEA2009。
文摘General history of disasters in China suggests that China has frequently experienced two major natural disasters in its long history,one is from catastrophic earthquake events,and the other is from extreme climatic events,due to its unique active tectonic environment and climatic complexity.Although these two major natural disasters have caused great damage to human society,it remains unclear whether and how they affect Chinese dynasty alternation on decadal(emperor)timescales.Based on detailed comparisons between abrupt climatic changes,catastrophic seismic activities,and the history of Chinese dynasty alternation from 1000–2000 AD,we conclude that on decadal timescales,extreme drought(and/or flood)events could indeed significantly reduce agricultural production,cause severe food shortages and famine,and result in increases in population exile,rising food prices and inflation,and insufficient supplies for military defense,which could exceed social resilience and eventually lead to financial risks and social upheavals of the dynasties.In addition,catastrophic seismic events in the densely populated,agricultural areas of China,including the 1303 surface wave magnitude(M_(s))8.0 Hongtong earthquake,the 1556 M_(s)8.25Huaxian earthquake and the 1920 M_(s)8.5 Haiyuan earthquake,caused more than 200,000casualties and millions of victims to live in exile which was almost equivalent to the order of magnitude of those extreme climatic events-induced refugees.The secondary geological hazards related to the earthquakes(e.g.,extensive landslides and soil erosion),which could last for decades,caused more casualties and reduced food production.Furthermore,great plague spread caused by the casualties could significantly increase psychological panic among the survivors,resulting in social instability.Therefore,catastrophic seismic events could also accelerate the collapse of the dynasties(e.g.,the Ming dynasty)without immediate mitigation measures.This study indicates that catastrophic seismic activities,as well as extreme climatic events,could have great effects on the social structures and thus on the Chinese dynasty alternation on decadal timescales,which highlights the far-reaching implications of geological hazard research.
