2019 was one of the hottest years in recent decades,with widespread heatwaves over many parts of the world,including Africa.However,as a developing and vulnerable region,the understanding of recent heatwave events in ...2019 was one of the hottest years in recent decades,with widespread heatwaves over many parts of the world,including Africa.However,as a developing and vulnerable region,the understanding of recent heatwave events in Africa is limited.Here,the authors incorporated different climate datasets,satellite observations,and population estimates to investigate patterns and hotspots of major heatwave events over Africa in 2019.Overall,2019 was one of the years that experienced the strongest heatwaves in terms of intensity and duration since 1981 in Africa.Heatwave hotspots were clearly identified across western-coastal,northeastern,southern,and equatorial Africa,where major cities and human populations are located.The proportion of urban agglomerations(population)exposed to extreme(99 th percentile)heatwaves in the Northern Hemisphere and Southern Hemisphere rose from 4%(5 million people)and 15%(17 million people),respectively,in the baseline period of 1981-2010 to36%(43 million people)and 57%(53 million people),respectively,in 2019.Heatwave patterns and hotspots in 2019 were related to anomalous seasonal change in atmospheric circulation and above-normal sea surface temperature.Without adaptation to minimize susceptibility to the effects of heatwave events,the risks they pose in populated areas may increase rapidly in Africa.展开更多
Based on an urbanization research database,a bibliometric analysis of Chinese ecological environmental research on urbanization was conducted that examined output,focused fields,topics,theories and methods.Results sho...Based on an urbanization research database,a bibliometric analysis of Chinese ecological environmental research on urbanization was conducted that examined output,focused fields,topics,theories and methods.Results show that research output in this field has been increasing since 2005.Land and industry fields in resource research,economics in ecological research,and climate and urban environments in environmental research have been studied from 1992–2011.Keywords analysis discovered that ＂Land Use＂ and ＂Heat Island Effect＂ were major keywords,making up 0.15% and 0.09% of the total frequency,respectively.＂Heat Island Effect＂ and ＂Climate Change＂ were the most recent popular keywords.Main theories were derived from ecology,mathematics,resource environmental economics and environmental science.Ecological footprint has been a core theory since 2002.The stochastic impacts by regression on population,affluence and technology model（STIRPAT）,Environmental Kuznets Curve（EKC）,and slope,land use map,excluded area,urban area,transportation map and hillside area model（SLEUTH） are the latest popular theories.During 1992–2011,the main research methods can be divided into four groups： statistics（65.17%）,systems（13.11%）,mechanisms（11.79%） and evaluation（9.93%）.Grey System Analysis from system methods and rescaled range（R/S） analysis from evaluation are the latest popular methods.Topics from macro subfields,including land use,heat island effects,water resources and the agricultural ecological environment received more attention than micro subfields such as urban environmental health problems.As urbanization problems evolve,resource environmental economic comprehensive models will advance with modeling progress and some models,such as STIRPAT and land use change simulation models,will be developed for evaluation and simulation of the ecological environmental impacts of Chinese urbanization.展开更多
基金funded by the National Natural Science Foundation of China[grant numbers 41861124005 and 41675079]the first author was a recipient of a research studentship provided by the CAS-TWAS President fellowship。
文摘2019 was one of the hottest years in recent decades,with widespread heatwaves over many parts of the world,including Africa.However,as a developing and vulnerable region,the understanding of recent heatwave events in Africa is limited.Here,the authors incorporated different climate datasets,satellite observations,and population estimates to investigate patterns and hotspots of major heatwave events over Africa in 2019.Overall,2019 was one of the years that experienced the strongest heatwaves in terms of intensity and duration since 1981 in Africa.Heatwave hotspots were clearly identified across western-coastal,northeastern,southern,and equatorial Africa,where major cities and human populations are located.The proportion of urban agglomerations(population)exposed to extreme(99 th percentile)heatwaves in the Northern Hemisphere and Southern Hemisphere rose from 4%(5 million people)and 15%(17 million people),respectively,in the baseline period of 1981-2010 to36%(43 million people)and 57%(53 million people),respectively,in 2019.Heatwave patterns and hotspots in 2019 were related to anomalous seasonal change in atmospheric circulation and above-normal sea surface temperature.Without adaptation to minimize susceptibility to the effects of heatwave events,the risks they pose in populated areas may increase rapidly in Africa.
基金National Natural Science Foundation of China(4127155641101117)
文摘Based on an urbanization research database,a bibliometric analysis of Chinese ecological environmental research on urbanization was conducted that examined output,focused fields,topics,theories and methods.Results show that research output in this field has been increasing since 2005.Land and industry fields in resource research,economics in ecological research,and climate and urban environments in environmental research have been studied from 1992–2011.Keywords analysis discovered that ＂Land Use＂ and ＂Heat Island Effect＂ were major keywords,making up 0.15% and 0.09% of the total frequency,respectively.＂Heat Island Effect＂ and ＂Climate Change＂ were the most recent popular keywords.Main theories were derived from ecology,mathematics,resource environmental economics and environmental science.Ecological footprint has been a core theory since 2002.The stochastic impacts by regression on population,affluence and technology model（STIRPAT）,Environmental Kuznets Curve（EKC）,and slope,land use map,excluded area,urban area,transportation map and hillside area model（SLEUTH） are the latest popular theories.During 1992–2011,the main research methods can be divided into four groups： statistics（65.17%）,systems（13.11%）,mechanisms（11.79%） and evaluation（9.93%）.Grey System Analysis from system methods and rescaled range（R/S） analysis from evaluation are the latest popular methods.Topics from macro subfields,including land use,heat island effects,water resources and the agricultural ecological environment received more attention than micro subfields such as urban environmental health problems.As urbanization problems evolve,resource environmental economic comprehensive models will advance with modeling progress and some models,such as STIRPAT and land use change simulation models,will be developed for evaluation and simulation of the ecological environmental impacts of Chinese urbanization.
