Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the i...Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.展开更多
[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling pl...[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling plots investigation and route survey,and the whole Dongjiang River was covered.52 sampling points were set in the main streams,and 87 sampling points in tributaries streams,624 quadrats were set in total;multi-index comprehensive evaluation method was adopted for the risk assessment with 6 first-level indexes and 25 second-level indexes.[Result] Through the investigation on the riparian zone of Dongjiang River for 2 years,51 species of alien invasive plants were found,belonging to 17 families and 38 genera.The risk level assessment results of these 51 species showed that 18 species,such as Ageratum conyzoides,belonged to high-level risk with over 60 points;26 species,such as Chenopodium ambrosioides,were between 30 and 60 points which belonged to middle-level risk;7 species,such as Paspalum dilatatum,with less than 30 points belonged to low-level risk.[Conclusion] Basic data on the protection,water environmental management and functional zoning of riparian zone of Dongjiang River were provided.展开更多
In order to facilitate engineering design and coastal flooding protection, the potential storm surge induced by a typhoon is studied.Using an unstructured mesh, a coupled model which combines the advanced circulation ...In order to facilitate engineering design and coastal flooding protection, the potential storm surge induced by a typhoon is studied.Using an unstructured mesh, a coupled model which combines the advanced circulation （ ADCIRC ） hydrodynamic model and simulating waves nearshore （ SWAN ） model is applied to analyze the storm surge and waves on the coast of Jiangsu Province.The verifications of wind velocity, tidal levels and wave height show that this coupling model performs well to reflect the characteristics of the water levels and waves in the studied region.Results show that the effect of radiation stress on storm surge is significant, especially in shallow areas such as the coast of Jiangsu Province and the Yangtze estuary.By running the coupled model, the simulated potential flooding results can be employed in coastal engineering applications in the Jiangsu coastal area, such as storm surge warnings and extreme water level predictions.展开更多
1 INTRODUCTIONAs confirmed by many studies, sea surface pressure is of interannual variations in subtropical Southern Hemisphere, which is defined as the Southern-hemisphere Annual Mode （SAM）. It is in fact a seesaw...1 INTRODUCTIONAs confirmed by many studies, sea surface pressure is of interannual variations in subtropical Southern Hemisphere, which is defined as the Southern-hemisphere Annual Mode （SAM）. It is in fact a seesaw effect of sea surface pressure symmetric longitudinally between the South Pole region and austral middle latitudes. SAM is in fact a correction to the Antarctic Atmospheric Oscillation （AAO）. At present, more attention is paid to the structure of SAM and its influence on the climate in mid- and higherlatitudes of SH than to the links between SAM and anomalies of boreal general circulation and climate. This work focuses on the relation among SAM in boreal spring （April - May）, Mei-yu （sustaining rains） in the middle and lower reaches of the Yangtze River and East Asian monsoon.展开更多
The purpose of this research was to better understand the water quality status of the Xiangjiang River, China, and to evaluate the risks posed by the river water. Precisely, ten water quality parameters including p H,...The purpose of this research was to better understand the water quality status of the Xiangjiang River, China, and to evaluate the risks posed by the river water. Precisely, ten water quality parameters including p H, dissolved oxygen(DO), Escherichia coli(E. coli), potassium permanganate index(CODMn), dichromate oxidizability(CODCr), five-day biochemical oxygen demand(BOD5), ammonia nitrogen(NH4+-N), total phosphorus(TP) and fluoride(F-) as well as metal(loid)s(Pb, Hg, Cd, As, Zn, Cu and Se) were monitored monthly in 2016 at 12 sampling sites throughout the Hengyang section of the Xiangjiang River. Concentrations of all parameters were presented according to rainy and dry seasons. They were compared with Chinese surface water standards and WHO drinking water limits to assess the sustainability of the river water status. Principal component analysis(PCA) revealed different pollution sources in different seasons. Dual hierarchical cluster analysis(DHCA) was applied to further classify the water quality variables and sampling sites. Besides, a risk assessment was introduced to evaluate the carcinogenic and non-carcinogenic concerns of heavy metal(loid)s to human health. This research will help to optimize water monitoring locations and establish pollution reduction strategies on the preservation of public safety.展开更多
基金supported by the 2nd Scientific Expedition to the Qinghai–Tibet Plateau[grant number 2019QZKK0102]the National Natural Science Foundation of China[grant number 42275045,41975012]+3 种基金the West Light Foundation of the Chinese Academy of Sciences[grant number xbzg-zdsys-202215]the Science and Technology Research Plan of Gansu Province[grant number 20JR10RA070]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number QCH2019004]iLEAPs(integrated Land Ecosystem–Atmosphere Processes Study).
文摘Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.
基金Supported by National Water Pollution Control and Management Technology Major Project of ChinaEcological Function Partition Research of Level Three and Level Four in Key Watershed(2012ZX07501002)the Fundamental Work Project of Ministry ofScience and Technology (2006FY111000)~~
文摘[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling plots investigation and route survey,and the whole Dongjiang River was covered.52 sampling points were set in the main streams,and 87 sampling points in tributaries streams,624 quadrats were set in total;multi-index comprehensive evaluation method was adopted for the risk assessment with 6 first-level indexes and 25 second-level indexes.[Result] Through the investigation on the riparian zone of Dongjiang River for 2 years,51 species of alien invasive plants were found,belonging to 17 families and 38 genera.The risk level assessment results of these 51 species showed that 18 species,such as Ageratum conyzoides,belonged to high-level risk with over 60 points;26 species,such as Chenopodium ambrosioides,were between 30 and 60 points which belonged to middle-level risk;7 species,such as Paspalum dilatatum,with less than 30 points belonged to low-level risk.[Conclusion] Basic data on the protection,water environmental management and functional zoning of riparian zone of Dongjiang River were provided.
基金The National Natural Science Foundation of China(No.51209040,51279134)the Natural Science Foundation of Jiangsu Province(No.BK2012341)+1 种基金the Fundamental Research Funds for the Central Universities(No.SJLX_0087)the Research Fund of Nanjing Hydraulic Research Institute(No.Y213012)
文摘In order to facilitate engineering design and coastal flooding protection, the potential storm surge induced by a typhoon is studied.Using an unstructured mesh, a coupled model which combines the advanced circulation （ ADCIRC ） hydrodynamic model and simulating waves nearshore （ SWAN ） model is applied to analyze the storm surge and waves on the coast of Jiangsu Province.The verifications of wind velocity, tidal levels and wave height show that this coupling model performs well to reflect the characteristics of the water levels and waves in the studied region.Results show that the effect of radiation stress on storm surge is significant, especially in shallow areas such as the coast of Jiangsu Province and the Yangtze estuary.By running the coupled model, the simulated potential flooding results can be employed in coastal engineering applications in the Jiangsu coastal area, such as storm surge warnings and extreme water level predictions.
基金"Research on Subtropical Monsoon and Development of Relevant Forecasting Techniques"from Shanghai Meteorological Bureau
文摘1 INTRODUCTIONAs confirmed by many studies, sea surface pressure is of interannual variations in subtropical Southern Hemisphere, which is defined as the Southern-hemisphere Annual Mode （SAM）. It is in fact a seesaw effect of sea surface pressure symmetric longitudinally between the South Pole region and austral middle latitudes. SAM is in fact a correction to the Antarctic Atmospheric Oscillation （AAO）. At present, more attention is paid to the structure of SAM and its influence on the climate in mid- and higherlatitudes of SH than to the links between SAM and anomalies of boreal general circulation and climate. This work focuses on the relation among SAM in boreal spring （April - May）, Mei-yu （sustaining rains） in the middle and lower reaches of the Yangtze River and East Asian monsoon.
基金Projects(2018YFC1801805,2018YFC1903301)supported by National Key R&D Program of ChinaProject(51825403)supported by National Science Fund for Distinguished Young Scholars,ChinaProject(2019SK2281)supported by Key R&D Program of Hunan Province,China。
文摘The purpose of this research was to better understand the water quality status of the Xiangjiang River, China, and to evaluate the risks posed by the river water. Precisely, ten water quality parameters including p H, dissolved oxygen(DO), Escherichia coli(E. coli), potassium permanganate index(CODMn), dichromate oxidizability(CODCr), five-day biochemical oxygen demand(BOD5), ammonia nitrogen(NH4+-N), total phosphorus(TP) and fluoride(F-) as well as metal(loid)s(Pb, Hg, Cd, As, Zn, Cu and Se) were monitored monthly in 2016 at 12 sampling sites throughout the Hengyang section of the Xiangjiang River. Concentrations of all parameters were presented according to rainy and dry seasons. They were compared with Chinese surface water standards and WHO drinking water limits to assess the sustainability of the river water status. Principal component analysis(PCA) revealed different pollution sources in different seasons. Dual hierarchical cluster analysis(DHCA) was applied to further classify the water quality variables and sampling sites. Besides, a risk assessment was introduced to evaluate the carcinogenic and non-carcinogenic concerns of heavy metal(loid)s to human health. This research will help to optimize water monitoring locations and establish pollution reduction strategies on the preservation of public safety.
