The preservation of historical and cultural heritage from seismic risk is a question of interest in Italy. However, too little has been done to deal with this problem. First of all, the seismic safety of cultural heri...The preservation of historical and cultural heritage from seismic risk is a question of interest in Italy. However, too little has been done to deal with this problem. First of all, the seismic safety of cultural heritage should be a topic of prevention. The research described in the paper presents a multi-approach procedure to address risk assessment of large-scale urban systems with the aim to contribute at the development of risk mitigation policies for historical centers buildings. The observation of the earthquakes effects in Italy clearly highlights the role of the high vulnerability of the existing building on the consequences in terms of casualties and damage, rather than the severity of seismic events, especially in historical contexts. Unlike the new buildings which should be planned and designed to respect seismic safety requirements, existing buildings require a careful safety assessment on the basis of their susceptibility to damage which depends on building techniques, past damage events, maintenance, changes, etc.展开更多
Fifty cases of regional yearly extreme precipitation events （RYEPEs） were identified over the Yangtze-Huaihe River Valley （YHRV） during 1979-2016 applying the statistical percentile method. There were five types o...Fifty cases of regional yearly extreme precipitation events （RYEPEs） were identified over the Yangtze-Huaihe River Valley （YHRV） during 1979-2016 applying the statistical percentile method. There were five types of RYEPEs, namely Yangtze Meiyu （YM-RYEPE）, Huaihe Meiyu （HM-RYEPE）, southwest-northeast-oriented Meiyu （SWNE-RYEPE） and typhoon I and II （TC-RYEPE） types of RYEPEs. Potential vorticity diagnosis showed that propagation trajectories of the RYEPEs along the Western Pacific Subtropical High and its steering flow were concentrated over the southern YHRV. As a result, the strongest and most frequently RYEPEs events, about 16-21 cases with average rainfall above 100 mm, occurred in the southern YHRV, particularly in the Nanjing metropolitan area. There have been 14 cases of flood-inducing RYEPEs since 1979, with the submerged area exceeding 120 km2 as simulated by the FloodArea hydraulic model, comprising six HM-RYEPEs, five YM- RYEPEs, two TC-RYEPEs, and one SWNE-RYEPE. The combination of evolving RYEPEs and rapid expansion of urban agglomeration is most likely to change the flood risk distribution over the Nanjing metropolitan area in the future. In the RCP6.0 （RCPS.5） scenario, the built-up area increases at a rate of about 10.41 km2 （10 yr）-t（24.67 km2 （10 yr）-1） from 2010 to 2100, and the area of high flood risk correspondingly increases from 3.86 km2（3.86 km2） to 9.00 kin2（13.51 km2）. Areas of high flood risk are mainly located at Chishan Lake in Jurong, Lukou International Airport in Nanjing, Dongshan in Jiangning District, Lishui District and other low-lying areas. The accurate simulation of flood scenarios can help reduce losses due to torrential flooding and improve early warnings, evacuation planning and risk analysis. More attention should be paid to the projected high flood risk because of the concentrated population, industrial zones and social wealth throughout the Nanjing metropolitan area.展开更多
Carbonyl-containing volatile organic compounds （cVOCs） are important precursors of atmospheric photochemical reactions in the formation of ozone, smog and other air pollutants. China＇s megacities are economically d...Carbonyl-containing volatile organic compounds （cVOCs） are important precursors of atmospheric photochemical reactions in the formation of ozone, smog and other air pollutants. China＇s megacities are economically developed and densely populated metropolitan areas, usually with a population over ten million; they drive the rapid growth of surrounding urban clusters. So far, 21 cVOCs have been detected in the atmosphere of these megacities. The average annual total concentration of cVOCs is 55.6 μg/m^3, an alarmingly high level. Vehicle emissions, industrial discharges, excessive use of organic solvents and other factors have led to a situation where hazardous formaldehyde, acetaldehyde and acetone account for 62.4 percent of the total atmospheric concentration of cVOC in Chinese cities. In a quantitative evaluation using daily exposure levels, cancer risk and hazardquotient, we found that the excessive levels of atmospheric cVOCs in Beijing, Shanghai and Guangzhou pose serious health risks to their inhabitants. Air pollution persists, despite the brief improvements in air quality brought about by the air quality campaign undertaken during major intemational events like the 2008 Olympic Games, the 2010 Asian Games, and the 2010 World Expo. The health risks caused by atmospheric cVOCs in Chinese cities require close attention.展开更多
文摘The preservation of historical and cultural heritage from seismic risk is a question of interest in Italy. However, too little has been done to deal with this problem. First of all, the seismic safety of cultural heritage should be a topic of prevention. The research described in the paper presents a multi-approach procedure to address risk assessment of large-scale urban systems with the aim to contribute at the development of risk mitigation policies for historical centers buildings. The observation of the earthquakes effects in Italy clearly highlights the role of the high vulnerability of the existing building on the consequences in terms of casualties and damage, rather than the severity of seismic events, especially in historical contexts. Unlike the new buildings which should be planned and designed to respect seismic safety requirements, existing buildings require a careful safety assessment on the basis of their susceptibility to damage which depends on building techniques, past damage events, maintenance, changes, etc.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41205063 & 41330529)the China Meteorological Administration Special Public Welfare Research Fund (Grant No. GYHY201506006)+1 种基金the Project of Development of Key Techniques in Meteorological Forecasting Operation (Grant No. CMAHX20160404)the Huaihe Basin Meteorological Research Foundation (Grant No. HRM201605)
文摘Fifty cases of regional yearly extreme precipitation events （RYEPEs） were identified over the Yangtze-Huaihe River Valley （YHRV） during 1979-2016 applying the statistical percentile method. There were five types of RYEPEs, namely Yangtze Meiyu （YM-RYEPE）, Huaihe Meiyu （HM-RYEPE）, southwest-northeast-oriented Meiyu （SWNE-RYEPE） and typhoon I and II （TC-RYEPE） types of RYEPEs. Potential vorticity diagnosis showed that propagation trajectories of the RYEPEs along the Western Pacific Subtropical High and its steering flow were concentrated over the southern YHRV. As a result, the strongest and most frequently RYEPEs events, about 16-21 cases with average rainfall above 100 mm, occurred in the southern YHRV, particularly in the Nanjing metropolitan area. There have been 14 cases of flood-inducing RYEPEs since 1979, with the submerged area exceeding 120 km2 as simulated by the FloodArea hydraulic model, comprising six HM-RYEPEs, five YM- RYEPEs, two TC-RYEPEs, and one SWNE-RYEPE. The combination of evolving RYEPEs and rapid expansion of urban agglomeration is most likely to change the flood risk distribution over the Nanjing metropolitan area in the future. In the RCP6.0 （RCPS.5） scenario, the built-up area increases at a rate of about 10.41 km2 （10 yr）-t（24.67 km2 （10 yr）-1） from 2010 to 2100, and the area of high flood risk correspondingly increases from 3.86 km2（3.86 km2） to 9.00 kin2（13.51 km2）. Areas of high flood risk are mainly located at Chishan Lake in Jurong, Lukou International Airport in Nanjing, Dongshan in Jiangning District, Lishui District and other low-lying areas. The accurate simulation of flood scenarios can help reduce losses due to torrential flooding and improve early warnings, evacuation planning and risk analysis. More attention should be paid to the projected high flood risk because of the concentrated population, industrial zones and social wealth throughout the Nanjing metropolitan area.
基金supported by the National Natural Science Foundation of China Fund(No.40975077)the National Natural Science Foundation of China and Guangdong Province Joint Fund(No.U1201232)
文摘Carbonyl-containing volatile organic compounds （cVOCs） are important precursors of atmospheric photochemical reactions in the formation of ozone, smog and other air pollutants. China＇s megacities are economically developed and densely populated metropolitan areas, usually with a population over ten million; they drive the rapid growth of surrounding urban clusters. So far, 21 cVOCs have been detected in the atmosphere of these megacities. The average annual total concentration of cVOCs is 55.6 μg/m^3, an alarmingly high level. Vehicle emissions, industrial discharges, excessive use of organic solvents and other factors have led to a situation where hazardous formaldehyde, acetaldehyde and acetone account for 62.4 percent of the total atmospheric concentration of cVOC in Chinese cities. In a quantitative evaluation using daily exposure levels, cancer risk and hazardquotient, we found that the excessive levels of atmospheric cVOCs in Beijing, Shanghai and Guangzhou pose serious health risks to their inhabitants. Air pollution persists, despite the brief improvements in air quality brought about by the air quality campaign undertaken during major intemational events like the 2008 Olympic Games, the 2010 Asian Games, and the 2010 World Expo. The health risks caused by atmospheric cVOCs in Chinese cities require close attention.
