Since 1988,great efforts and enthusiasm had been paid by applied geochemists in the implementation of global geochemical mapping through the International Geological Correlation Program＇s Projects 259 and 360,and the...Since 1988,great efforts and enthusiasm had been paid by applied geochemists in the implementation of global geochemical mapping through the International Geological Correlation Program＇s Projects 259 and 360,and the Task Group on‘Global Geochemical Baselines＇ established by the International Union of Geological Sciences（IUGS）,in collaboration with the International Association of Geochemistry（IAGC）.But how to use extremely low-density sampling to obtain a global picture of the distribution of most elements in the periodic table in a reasonably short time is still a great challenge faced by the applied geochemistry community.It will depend on the continuous development of new mapping concept,and the advisable and courageous innovation of methodology for searching other suitable sample media and sampling layout.Based on the encouragement results obtained from the representativeness study of delta sediments conducted at the mouth of Yangtze River,and at the mouths of its four major tributary,it is expected to broadly apply the geochemical fractal self-similarity nature to main rivers and their estuaries with catchments up to hundreds of thousands or over a million square kilometers in the world.With this new mapping concept,a new outlines of a Global Geochemical Mapping Program was advanced and the establishment of an International Research Center of Global Geochemical Mapping was also suggested to facilitate the programs implementations.展开更多
The middle and lower reaches of the Yangtze River,a primary region for freshwater lakes in China,have undergone significant transformations throughout the Holocene.These changes,driven by factors such as sea-level ris...The middle and lower reaches of the Yangtze River,a primary region for freshwater lakes in China,have undergone significant transformations throughout the Holocene.These changes,driven by factors such as sea-level rise,climate change,and human activities,have led to the progressive elevation of water levels in this area.As a result,a floodplain has emerged,characterized by the formation of numerous shallow lakes along the river course.However,the pattern of water-level changes in the main channel of the Yangtze River during the Holocene remains unclear.This gap in knowledge poses challenges for understanding sediment transport dynamics,the interactions between the river and its adjacent lakes,and the prevention and control of flood disasters in the Yangtze River basin.To shed light on these issues,our study compiled data on the surface elevation and water depth of 81 lakes in the mid-lower reaches of the Yangtze River basin.Additionally,we analyzed historical water-level records from the 1900s to the 1970s at eight gauging stations from Shashi to Jiangyin along the river’s main stream.Our findings reveal that,particularly along the Jingjiang section,the basal elevation of most lakes is lower than the Yangtze River’s water level during the dry season.Conversely,the water level of the main stream exceeds that of both the floodplain and the lakes enclosed by the Jingjiang embankment.In the tidal reach,especially within the Taihu Lake basin,the basal elevation of lakes typically falls below sea level.Meanwhile,lakes located along the section from Chenglingji to Wuhu exhibit basal elevations that correspond with the Yangtze River’s annual average and dry season water levels.Given the widespread presence of lakes along the middle and lower reaches of the Yangtze River,our study introduces a new proxy for reconstructing the mean water level of the mid-lower Yangtze River in the Holocene.By analyzing sediments from Nanyi Lake and Chenyao Lake in the lower Yangtze River,we attempted to reconstruct the water level of展开更多
Seasonal variability of dissolved and particulate methylmercury（F-MeHg, P-MeHg） concentrations was studied in the waters of the Amazon River and its associated Curuai floodplain during hydrological year 2005–2006, ...Seasonal variability of dissolved and particulate methylmercury（F-MeHg, P-MeHg） concentrations was studied in the waters of the Amazon River and its associated Curuai floodplain during hydrological year 2005–2006, to understand the MeHg exchanges between these aquatic systems. In the oxic white water lakes, with neutral pH, high F-MeHg and P-MeHg concentrations were measured during the rising water stage（0.70 ± 0.37 pmol/L, n = 26） and flood peak（14.19 ± 9.32 pmol/g, n = 7） respectively, when the Amazon River water discharge into the lakes was at its maximum. The lowest mean values were reported during the dry season（0.18 ± 0.07 pmol/L F-MeHg, n = 10 and 1.35 ± 1.24 pmol/g P-MeHg, n = 8）, when water and suspended sediments were outflowing from the lakes into the River. In these lakes,the MeHg concentrations were associated to the aluminium and organic carbon/nitrogen changes. In the black water lakes, with acidic pH and reducing conditions, elevated MeHg concentrations were recorded（0.58 ± 0.32 pmol/L F-MeHg, n = 16 and 19.82 ± 15.13 pmol/g PMeHg, n = 6）, and correlated with the organic carbon and manganese concentrations. Elevated values of MeHg partition coefficient（4.87 〈 Kd〈 5.08 log（L/kg） indicate that MeHg is mainly transported associated with the particulate phase. The P-MeHg enrichment detected in all lakes suggests autochthonous MeHg inputs from the sediments into the water column. The MeHg mass balance showed that the Curuai floodplain is not the source of P-MeHg for the Amazon River.展开更多
Results obtained from the wide spaced floodplain sediments indicate that the abundances of Pt and Pd in floodplain sediments are 0.46 ng/g and 0.40 ng/g, respectively. Three geochemical provinces, Yunnan Guizhou, Xinj...Results obtained from the wide spaced floodplain sediments indicate that the abundances of Pt and Pd in floodplain sediments are 0.46 ng/g and 0.40 ng/g, respectively. Three geochemical provinces, Yunnan Guizhou, Xinjiang Gansu and Tibet of Pt and Pd with a content of 0.8 ng/g, were delineated.展开更多
To understand the pollution characteristics and distributions of microplastics in the Dagu River,an important inland river that flows to Jiaozhou Bay,the abundance,particle size,shape,color,and polymer type of micropl...To understand the pollution characteristics and distributions of microplastics in the Dagu River,an important inland river that flows to Jiaozhou Bay,the abundance,particle size,shape,color,and polymer type of microplastics in the surface waters and floodplain sediments were investigated.The results showed that the abundance of microplastics in the surface waters varied between 0.68 and 3.96 items L^(−1).The abundance of microplastics in the floodplain sediments varied between 115.5 and 495 items kg^(−1).The distribution of microplastics in the river has obvious characteristics:1)The abundance of microplastics downstream was significantly higher than that upstream.2)The abundance of microplastics decreased significantly in the estuary.3)The abundance of microplastics was higher in densely populated areas.4)Factors such as effluent discharge from sewage treatment plants and inflow of tributaries affect the abundance of microplastics in rivers.The main polymer types of microplastics were polypropylene(PP),polyethylene(PE),and polyvinyl chloride(PVC).Both the abundance and polymer types of microplastics show a positive correlation between the surface waters and floodplain sediment samples,indicating that the microplastics in surface waters and floodplain sediments come from the same source.The present study demonstrates that the abundance,distribution,and sources of microplastics might be affected by geology,hydrogeology,land use types,and anthropogenic activities.This study provides basic data for the study of microplastics in rivers and provides a reference for the establishment of microplastic control measures.展开更多
基金the China Geological Survey and the Ministry of Science and Technology for financial support(CGS 1212010911036,SinoProbe-04)support the new outline of global geochemical mapping programmeto the institutes and organizations which support the establishment of IRCGM in Langfang China.
文摘Since 1988,great efforts and enthusiasm had been paid by applied geochemists in the implementation of global geochemical mapping through the International Geological Correlation Program＇s Projects 259 and 360,and the Task Group on‘Global Geochemical Baselines＇ established by the International Union of Geological Sciences（IUGS）,in collaboration with the International Association of Geochemistry（IAGC）.But how to use extremely low-density sampling to obtain a global picture of the distribution of most elements in the periodic table in a reasonably short time is still a great challenge faced by the applied geochemistry community.It will depend on the continuous development of new mapping concept,and the advisable and courageous innovation of methodology for searching other suitable sample media and sampling layout.Based on the encouragement results obtained from the representativeness study of delta sediments conducted at the mouth of Yangtze River,and at the mouths of its four major tributary,it is expected to broadly apply the geochemical fractal self-similarity nature to main rivers and their estuaries with catchments up to hundreds of thousands or over a million square kilometers in the world.With this new mapping concept,a new outlines of a Global Geochemical Mapping Program was advanced and the establishment of an International Research Center of Global Geochemical Mapping was also suggested to facilitate the programs implementations.
基金supported by the National Natural Science Foundation of China(Grant No.41972194)the Study on the Origin of Chinese Civilization in Jiangsu Province。
文摘The middle and lower reaches of the Yangtze River,a primary region for freshwater lakes in China,have undergone significant transformations throughout the Holocene.These changes,driven by factors such as sea-level rise,climate change,and human activities,have led to the progressive elevation of water levels in this area.As a result,a floodplain has emerged,characterized by the formation of numerous shallow lakes along the river course.However,the pattern of water-level changes in the main channel of the Yangtze River during the Holocene remains unclear.This gap in knowledge poses challenges for understanding sediment transport dynamics,the interactions between the river and its adjacent lakes,and the prevention and control of flood disasters in the Yangtze River basin.To shed light on these issues,our study compiled data on the surface elevation and water depth of 81 lakes in the mid-lower reaches of the Yangtze River basin.Additionally,we analyzed historical water-level records from the 1900s to the 1970s at eight gauging stations from Shashi to Jiangyin along the river’s main stream.Our findings reveal that,particularly along the Jingjiang section,the basal elevation of most lakes is lower than the Yangtze River’s water level during the dry season.Conversely,the water level of the main stream exceeds that of both the floodplain and the lakes enclosed by the Jingjiang embankment.In the tidal reach,especially within the Taihu Lake basin,the basal elevation of lakes typically falls below sea level.Meanwhile,lakes located along the section from Chenglingji to Wuhu exhibit basal elevations that correspond with the Yangtze River’s annual average and dry season water levels.Given the widespread presence of lakes along the middle and lower reaches of the Yangtze River,our study introduces a new proxy for reconstructing the mean water level of the mid-lower Yangtze River in the Holocene.By analyzing sediments from Nanyi Lake and Chenyao Lake in the lower Yangtze River,we attempted to reconstruct the water level of
基金This work was supported by the Yellow River Engineering Consulting Co.,Ltd.(Grant No.2019GS007-WW03/20)the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin(Grant No.SKL2020ZY10).
基金a PhD grant delivered by the Alban Programthe European Union Program of High Level Scholarship for Latin American, scholarship no.E04D0445592BR
文摘Seasonal variability of dissolved and particulate methylmercury（F-MeHg, P-MeHg） concentrations was studied in the waters of the Amazon River and its associated Curuai floodplain during hydrological year 2005–2006, to understand the MeHg exchanges between these aquatic systems. In the oxic white water lakes, with neutral pH, high F-MeHg and P-MeHg concentrations were measured during the rising water stage（0.70 ± 0.37 pmol/L, n = 26） and flood peak（14.19 ± 9.32 pmol/g, n = 7） respectively, when the Amazon River water discharge into the lakes was at its maximum. The lowest mean values were reported during the dry season（0.18 ± 0.07 pmol/L F-MeHg, n = 10 and 1.35 ± 1.24 pmol/g P-MeHg, n = 8）, when water and suspended sediments were outflowing from the lakes into the River. In these lakes,the MeHg concentrations were associated to the aluminium and organic carbon/nitrogen changes. In the black water lakes, with acidic pH and reducing conditions, elevated MeHg concentrations were recorded（0.58 ± 0.32 pmol/L F-MeHg, n = 16 and 19.82 ± 15.13 pmol/g PMeHg, n = 6）, and correlated with the organic carbon and manganese concentrations. Elevated values of MeHg partition coefficient（4.87 〈 Kd〈 5.08 log（L/kg） indicate that MeHg is mainly transported associated with the particulate phase. The P-MeHg enrichment detected in all lakes suggests autochthonous MeHg inputs from the sediments into the water column. The MeHg mass balance showed that the Curuai floodplain is not the source of P-MeHg for the Amazon River.
文摘Results obtained from the wide spaced floodplain sediments indicate that the abundances of Pt and Pd in floodplain sediments are 0.46 ng/g and 0.40 ng/g, respectively. Three geochemical provinces, Yunnan Guizhou, Xinjiang Gansu and Tibet of Pt and Pd with a content of 0.8 ng/g, were delineated.
基金financially supported by the National Major Special Project for Water Pollution Treatment and Control ‘Technology Integration of Watershed Ecological Function Zoning Management’ Project (No. 2017ZX073 01-001)the National Key Research and Development Program of China (No. 2018YFC1407601)。
文摘To understand the pollution characteristics and distributions of microplastics in the Dagu River,an important inland river that flows to Jiaozhou Bay,the abundance,particle size,shape,color,and polymer type of microplastics in the surface waters and floodplain sediments were investigated.The results showed that the abundance of microplastics in the surface waters varied between 0.68 and 3.96 items L^(−1).The abundance of microplastics in the floodplain sediments varied between 115.5 and 495 items kg^(−1).The distribution of microplastics in the river has obvious characteristics:1)The abundance of microplastics downstream was significantly higher than that upstream.2)The abundance of microplastics decreased significantly in the estuary.3)The abundance of microplastics was higher in densely populated areas.4)Factors such as effluent discharge from sewage treatment plants and inflow of tributaries affect the abundance of microplastics in rivers.The main polymer types of microplastics were polypropylene(PP),polyethylene(PE),and polyvinyl chloride(PVC).Both the abundance and polymer types of microplastics show a positive correlation between the surface waters and floodplain sediment samples,indicating that the microplastics in surface waters and floodplain sediments come from the same source.The present study demonstrates that the abundance,distribution,and sources of microplastics might be affected by geology,hydrogeology,land use types,and anthropogenic activities.This study provides basic data for the study of microplastics in rivers and provides a reference for the establishment of microplastic control measures.
