Particulate matter(PM_(2.5))pollution in high emission regions will affect air quality,human health and climate change on both local and regional scales,and thus attract worldwide attention.In this study,a comprehensi...Particulate matter(PM_(2.5))pollution in high emission regions will affect air quality,human health and climate change on both local and regional scales,and thus attract worldwide attention.In this study,a comprehensive study on PM_(2.5)and its chemical composition were performed in Yuncheng(the most polluted city of Fen-Wei Plain of China)from November28,2020 to January 24,2021.The average concentration of PM_(2.5)was 87.8±52.0μg/m^(3),which were apparently lower than those observed during the same periods of past five years,attributable to the clean air action plan implemented in this region.NO_(3)^(-)and organic carbon(OC)were the dominant particulate components,which on average contributed 22.6%and16.5%to PM_(2.5)2.5,respectively.The fractions of NO_(3)^(-),NH_(4)^(+),OC and trace metals increased while those of crustal materials and elemental carbon decreased with the degradation of PM_(2.5)pollution.Six types of PM_(2.5)sources were identified by the PM_(2.5)F model,including secondary inorganic aerosol(35.3%),coal combustion(28.7%),vehicular emission(20.7%),electroplating industry(8.6%),smelt industry(3.9%)and dust(2.8%).Locations of each identified source were pinpointed based on conditional probability function,potential source contribution function and concentration weighted trajectory,which showed that the geographical distribution of the sources of PM_(2.5)roughly agreed with the areas of high emission.Overall,this study provides valuable information on atmospheric pollution and deems beneficial for policymakers to take informed action to sustainably improve air quality in highly polluted region.展开更多
This paper takes Fen-Wei Basin(FWB)as a case to study the ground fissures controlled by normal fault.Based on the field investigation,geophysical exploration,drilling,GNSS data and numerical calculation,the characteri...This paper takes Fen-Wei Basin(FWB)as a case to study the ground fissures controlled by normal fault.Based on the field investigation,geophysical exploration,drilling,GNSS data and numerical calculation,the characteristics and mechanism of ground fissures originated from the hanging wall of normal faults are revealed.The results show that the distribution of ground fissures in the hanging wall and heading wall of the active faults is not uniform.Ground fissures are mostly distributed in the hanging wall of active faults and show a linear distribution on the surface,their strike is consistent with the fault,mainly characterized by vertical offset and horizontal tension.Ground fissures destroy the farmland and building foundation through which they pass and cause the rupture or displacement.In profile section,the ground fissure shows the characteristics of normal faults and dislocates the strata,and is connected with the underlying faults.Numerical analysis shows that the vertical displacement of normal fault activity in hanging wall is much larger than that in heading wall,which is the reason that tectonic ground fissures mainly originate from hanging wall.The range of dangerous area of ground fissures is controlled by the depth of fault,the strength of the ground fissures disaster is mainly controlled by the activity of fault.The formation of the ground fissures originated from the hanging wall of the fault experienced three stages:the main fault activity stage,the secondary fault activity stage and the fissure formation stage.展开更多
Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood...Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood are natural disasters bringing about the most serious damage, and drought risk in east central Weihe Plain is serious. In Fen-wei Plain, precipitation tended to decrease, and temperature, drought days and intensity increased over the past 50 years. There were obvious differences between two decades in drought and flood. Drought was the severest in the 1990s, and flood was the most serious in Fenhe Plain in the 1960s and in Weihe Plain from the late 1970s to the early 1980s. Over the past ten years, precipitation and flood frequency increased, and temperature, drought days and intensity decreased. In Fen-wei Plain, temperature will rise and precipitation will increase slightly in next 20 -40 years. Monitoring and early warning capability of drought and flood in Fen-wei Plain have im- proved gradually, but some issues need to be paid more attention to and solved.展开更多
基金supported by the National Key Research and Development Program of China(No.2019YFC0214203)
文摘Particulate matter(PM_(2.5))pollution in high emission regions will affect air quality,human health and climate change on both local and regional scales,and thus attract worldwide attention.In this study,a comprehensive study on PM_(2.5)and its chemical composition were performed in Yuncheng(the most polluted city of Fen-Wei Plain of China)from November28,2020 to January 24,2021.The average concentration of PM_(2.5)was 87.8±52.0μg/m^(3),which were apparently lower than those observed during the same periods of past five years,attributable to the clean air action plan implemented in this region.NO_(3)^(-)and organic carbon(OC)were the dominant particulate components,which on average contributed 22.6%and16.5%to PM_(2.5)2.5,respectively.The fractions of NO_(3)^(-),NH_(4)^(+),OC and trace metals increased while those of crustal materials and elemental carbon decreased with the degradation of PM_(2.5)pollution.Six types of PM_(2.5)sources were identified by the PM_(2.5)F model,including secondary inorganic aerosol(35.3%),coal combustion(28.7%),vehicular emission(20.7%),electroplating industry(8.6%),smelt industry(3.9%)and dust(2.8%).Locations of each identified source were pinpointed based on conditional probability function,potential source contribution function and concentration weighted trajectory,which showed that the geographical distribution of the sources of PM_(2.5)roughly agreed with the areas of high emission.Overall,this study provides valuable information on atmospheric pollution and deems beneficial for policymakers to take informed action to sustainably improve air quality in highly polluted region.
基金supported by the National Science Foundation of China (Nos.41790441,41877250,41272284,41807234)the National Geological Survey of China (No.DD20160264)the Fundamental Research Funds for the Central University,CHD (No.300102261715)
文摘This paper takes Fen-Wei Basin(FWB)as a case to study the ground fissures controlled by normal fault.Based on the field investigation,geophysical exploration,drilling,GNSS data and numerical calculation,the characteristics and mechanism of ground fissures originated from the hanging wall of normal faults are revealed.The results show that the distribution of ground fissures in the hanging wall and heading wall of the active faults is not uniform.Ground fissures are mostly distributed in the hanging wall of active faults and show a linear distribution on the surface,their strike is consistent with the fault,mainly characterized by vertical offset and horizontal tension.Ground fissures destroy the farmland and building foundation through which they pass and cause the rupture or displacement.In profile section,the ground fissure shows the characteristics of normal faults and dislocates the strata,and is connected with the underlying faults.Numerical analysis shows that the vertical displacement of normal fault activity in hanging wall is much larger than that in heading wall,which is the reason that tectonic ground fissures mainly originate from hanging wall.The range of dangerous area of ground fissures is controlled by the depth of fault,the strength of the ground fissures disaster is mainly controlled by the activity of fault.The formation of the ground fissures originated from the hanging wall of the fault experienced three stages:the main fault activity stage,the secondary fault activity stage and the fissure formation stage.
基金Supported by the Major Consulting Project of the Chinese Academy of Engineering(2012-ZD-13)Science and Technology Research and Development Program of Shaanxi Province,China(2014k13-09)
文摘Based on the latest results and data of drought and flood in Fen-wei Plain, current situation and evolution of drought and flood in Fen-wei Plain were analyzed. The results show that in Fen-wei Plain drought and flood are natural disasters bringing about the most serious damage, and drought risk in east central Weihe Plain is serious. In Fen-wei Plain, precipitation tended to decrease, and temperature, drought days and intensity increased over the past 50 years. There were obvious differences between two decades in drought and flood. Drought was the severest in the 1990s, and flood was the most serious in Fenhe Plain in the 1960s and in Weihe Plain from the late 1970s to the early 1980s. Over the past ten years, precipitation and flood frequency increased, and temperature, drought days and intensity decreased. In Fen-wei Plain, temperature will rise and precipitation will increase slightly in next 20 -40 years. Monitoring and early warning capability of drought and flood in Fen-wei Plain have im- proved gradually, but some issues need to be paid more attention to and solved.
