We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),org...We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),organics(33%)constituted the largest fraction,followed by nitrate(30%),sulfate(18%),ammonium(15%),chloride(3%),and rBC(2%).Four organic aerosol(OA)subcomponents were identified,including two primary OA(POA)and two secondary OA(SOA).The less-oxidized SOA(LO-OOA)contributes the most to the total OA mass(59%).LO-OOA is tightly correlated with the tracer ion C_(2)H_(4)O_(2)^(+)from levoglucosan,and another aged biomass-burning derived species,K_(3)SO_(4)^(+),suggesting it was likely influenced by aged biomass-burning OA.Our study also revealed that fireworks during the Spring Festival have a detrimental impact on air quality,contributing to secondary formation and accumulation under static winter meteorological conditions,prolonging the pollution duration.Also,LO-OOA was found to have the strongest light-absorbing ability.Our results highlight that the light absorption of LO-OOA can mainly be attributed to the C_(x)H_(y)N^(+) family,increased with the double-bond equivalent value.The more-oxidized SOA(MO-OOA)exhibited a negligible light absorption and was strongly correlated with daytime photochemical processes,implying a light-bleaching effect.This study enhances our understanding of the regional contribution of biomass combustion and fireworks to PM_(1) pollution in Nanjing,a typical megacity in the Yangtze River Delta region,during winter,aiding in the development of strategies for long-term air quality improvement in the region.展开更多
Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environment...Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environmental factors.Therefore,we investigated the spatiotemporal characteristics of wetland ecological quality in the MYRB from 2001 to 2020.Utilizing the random forest(RF)regression algorithm and patch-generated land-use simulation(PLUS)model,we forecasted variations in wetland habitat quality and their determinants under the Shared Socioeconomic Pathway-Representative Concentration Pathway(SSPRCP)framework from 2035 to 2095.The main findings are as follows:(1)The RF algorithm was optimal for land-use and land-cover(LULC)classification in the MYRB from 2001 to 2020,when notable changes were observed in water bodies and buildings.However,the forested area exhibited an increase and decrease of 3.9%and 1.2%under the SSP1-2.6 and SSP5-8.5 scenarios,respectively,whereas farmland exhibited a diminishing trend.(2)Wetlands were primarily concentrated in the central and eastern MYRB,with counties in the southwest exhibiting superior ecological-environmental quality from 2001 to 2020.Notably,wetland coverage revealed significantly high level,significant changes,frequent but relatively minor changes under the SSP1-2.6,SSP2-4.5,and SSP 5-8.5 scenarios,respectively.(3)Regions with lower habitat quality were primarily concentrated in urbanized areas characterized by frequent human activities,indicating a clear degradation in habitat quality across different scenarios.In conclusion,we established a foundational framework for future investigations into the eco-hydrological processes and ecosystem quality of watersheds.展开更多
Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable developm...Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable development.This study analyzed the spatiotemporal evolution and landscape pattern change of construction land in the Yangtze River Delta(YRD)region from 1990 to 2018 by integrating Geographical Information System(GIS)spatial analysis and landscape pattern indices,and revealed its driving mechanism by XGBoost and SHapley Additive ex Planations(SHAP).Moreover,we compared the disparities in the core driving factors for construction land evolution in cities with diverse development orientations within the YRD region.Results show that:1)development intensity of construction land continued to increase from 7.54%in 1990 to 13.44%in 2018,primarily by occupying farmland.The landscape fragmentation of construction land in the YRD region decreased,and landscape dominance increased.Spatially,the eastern part of the YRD exhibits a high degree of spatial agglomeration of construction land,whereas the western part shows a high degree of fragmentation,revealing distinct spatial gradient differentiation characteristics.The landscape dominance of the construction land in the eastern region of the YRD is higher than that in the western and northern regions.2)Transportation and infrastructure exert the highest contribution rate on development intensity changes of construction land in the YRD.The industrial structure significantly influences the conversion of farmland to construction land.Additionally,infrastructure plays a crucial role in shaping the spatial agglomeration patterns of construction land.Population distribution is the dominant factor determining the regularity of the landscape shape of construction land.3)The core driving factors for the development intensity of construction land in central cities primarily lies in transportation,whereas for non-central cities,besides transportation,the year-end balance of per capita savings deposits of urban and rural residents also play a significant role.The area change of construction land occupying farmland in central and non-central cities is mainly driven by industrial structure and economic level,respectively.This study informs refined spatial optimization and regional high-quality integrated development.展开更多
This study focuses on the spatiotemporal distribution,urban-rural variations,and driving factors of ammonia Vertical Column Densities(VCDs)in China’s Yangtze River Delta region(YRD)from 2008 to 2020.Utilizing data fr...This study focuses on the spatiotemporal distribution,urban-rural variations,and driving factors of ammonia Vertical Column Densities(VCDs)in China’s Yangtze River Delta region(YRD)from 2008 to 2020.Utilizing data from the Infrared Atmospheric Sounding Interfer-ometer(IASI),Generalized Additive Models(GAM),and the GEOS-Chem chemical transport model,we observed a significant increase of NH_(3)VCDs in the YRD between 2014 and 2020.The spatial distribution analysis revealed higher NH_(3)concentrations in the northern part of the YRD region,primarily due to lower precipitation,alkaline soil,and intensive agricul-tural activities.NH_(3)VCDs in the YRD region increased significantly(65.18%)from 2008 to 2020.The highest growth rate occurs in the summer,with an annual average growth rate of 7.2%during the period from 2014 to 2020.Agricultural emissions dominated NH_(3)VCDs during spring and summer,with high concentrations primarily located in the agricultural areas adjacent to densely populated urban zones.Regions within several large urban areas have been discovered to exhibit relatively stable variations in NH_(3)VCDs.The rise in NH_(3)VCDs within the YRD region was primarily driven by the reduction of acidic gases like SO_(2),as emphasized by GAM modeling and sensitivity tests using the GEOS-Chem model.The concentration changes of acidic gases contribute to over 80%of the interannual variations in NH_(3)VCDs.This emphasizes the crucial role of environmental policies targeting the reduction of these acidic gases.Effective emission control is urgent tomitigate environmental hazards and secondary particulate matter,especially in the northern YRD.展开更多
Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the ...Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.展开更多
[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-l...Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological variables.The results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,respectively.The meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive areas.Based on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,respectively.The spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic conditions.The central urban agglomeration north and south of the YRD was particularly susceptible to local pollution.Among the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.展开更多
Tour Overview.“Yangtze River Fantasy Tour-Charm of the Yangtze”is a carefully crafted 6-night,7-day journey for you to fully experience the endless charm of China's Yangtze River.On this trip,tourists will embar...Tour Overview.“Yangtze River Fantasy Tour-Charm of the Yangtze”is a carefully crafted 6-night,7-day journey for you to fully experience the endless charm of China's Yangtze River.On this trip,tourists will embark on a top luxury cruise ship on China,s inland rivers,sailing through the Yangtze River,enjoying comfort and luxury.The modern design and complete facilities of the cruise ship not only provide first-class accommodation but also offer a variety of onboard entertainment activities,filling your journey with laughter and joy.展开更多
Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used...Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used stable isotopes of hydrogen and oxygen to quantitatively analyze the water contribution and nutrient source structure of the tributary backwater area.Results showed that the isotope content(δD:−54.7‰,δ^(18)O−7.8‰)in the Yangtze River was higher than that in the tributaries(δD:−74.2‰,δ^(18)O−17.0‰)in the non-flood season and lower than that in the tributaries in the flood season.The Yangtze River contributed more than 50%water volume of the tributary backwater area in the non-flood season.The total nitrogen and total phosphorus concentrations in the backwater area were estimated based on water contribution ratio,and the results were in good agreement with the monitoring results.Load estimation showed that the nitrogen and phosphorus contribution ratio of the Yangtze River to the tributary backwater area was approximately 40%-80%in the non-flood season,and approximately 20%-40%in the flood season,on average.This study showed that the interaction between the Xiaojiang River and the Yangtze River is significant,and that Yangtze River recharge is an important source of nutrients in the Xiaojiang backwater area,which may play a driving role in Xiaojiang River algal blooms.展开更多
Synthetic phenolic antioxidants(SPAs)and parabens,particularly the high-molecularweight(HMW)SPAs and long alkyl chain(LAC)parabens with higher environmental persistence and toxicities,are widely produced and applied w...Synthetic phenolic antioxidants(SPAs)and parabens,particularly the high-molecularweight(HMW)SPAs and long alkyl chain(LAC)parabens with higher environmental persistence and toxicities,are widely produced and applied worldwide.However,their occurrence and potential risks in aquatic environments remain largely unknown.This work investigated 11 HMW SPAs and 3 LAC parabens in the river and treated industrial wastewater samples along the Yangtze River,the largest river and most important source water in China.For convenience of comparison,6 short alkyl chain(SAC)parabens were also included.In 15 industrial wastewater treatment plant effluents(effluent-IWTPs)and 34 surface water monitoring sections along the river,19 out of 20 target compounds were detected with total concentrations(TCs)from 152.5 to 1955.5 ng/L and 141.3 to 1364.9 ng/L in effluent-IWTPs and surface water,respectively.HMW SPAs 1,3,5-tris-[(3,5-di–tert–butyl–4-hydroxyphenyl)methyl]-1,3,5-triazinane-2,4,6-trione(AO3114)and octadecyl 3-(3,5-di–tert–butyl–4-hydroxyphenyl)propionate(AO1076)were the dominant ones.HMWSPAs bis(3–tert–butyl–4–hydroxy-5-methylphenyl)propionate(AO245)and 4,4'-sulfanediylbis(2–tert–butyl–5-methylphenol)(AO-TBM6)and SAC parabens propylparaben(PrP)and butylparaben(BuP)posed medium to high potential ecological risks in 27 surface water monitoring sections.Additionally,AO-TBM6 also exhibited potential health risks in 2 out of 11 drinking water sources.Though the ecotoxicity data are very limited,the ubiquitous presence of the LAC parabens including hexylparaben(HeP)and octylparaben(OcP)in surface water should be of concern since these compounds usually exhibit stronger estrogen potencies than the SAC ones.Finally,kernel density analysis revealed that regulation of industrial discharges is necessary to mitigate the HMW SPA and paraben contamination.展开更多
Welcome to the China Travel column!This section is dedicated to providing both Chinese and international readers with a comprehensive platform to explore China's rich cultural and tourism resources.Here,we will pr...Welcome to the China Travel column!This section is dedicated to providing both Chinese and international readers with a comprehensive platform to explore China's rich cultural and tourism resources.Here,we will present China's natural landscapes,historic sites,folk customs,and modern developments in both Chinese and English.展开更多
The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the min...The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the mineralization-related mafic-ultramafic rocks,the intermediate-acid intrusive rocks are also exposed in the mining area,which is of great significance for the understanding the Neoproterozoic tectonic evolution of the Yangtze Block,but studies on these intermediate-acid rocks are scarce.The Bijigou mafic-ultramafic layered intrusion is surrounded by granite and cut by syenite veins.Here,we report new zircon U-Pb ages,Lu-Hf isotope composition and bulk rock geochemical data of the Bijigou syenite vein and wall-rock granite in the northwestern margin of the Yangtze Block.Laser ablation inductively coupled plasma mass spectrometry(LAICP-MS)zircon U-Pb dating results show that the Bijigou syenite vein and wall-rock granite formed at 770±3.5 Ma(MSWD=0.17,n=28)and 810±4 Ma(MSWD=0.84,n=26),respectively.The zirconεHf(t)values of the syenite veins range from+1.52 to+5.33(average of+3.05),combined with its high potassium contents,negative Nb–Ta anomalies and positive Pb anomalies,suggesting that they may have originated from mantle-derived basaltic magma,which was modified by materials from subducting oceanic slab.The zirconεHf(t)and T_(DM2)ages of the wall-rock granite range from+0.71 to+5.71(average+3.06)and 1344 to 1659 Ma(average 1519 Ma),respectively,indicating that the granite was produced by partial melting of juvenile crust.The geochemical characteristics of the Bijigou syenite and granite indicate that they were formed in a continental margin arc setting.Thus,combined with previous studies,it suggests that there was a major subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma,and the magmatism in the Hannan massif was divided into two episodes:(1)early magmatism(824-790 Ma),such as the Bijigou,Hongmiaozhen and Huangguanzhen granitoids,was derived from partial melting of the juvenile or pre-existing crust in a continental arc setting;(2)later magmatism(789-718 Ma),including Bijigou syenite,Wudumen,Erliba and Zushidian granitoids,formed in a subduction-related back-arc extensional environment.The long-term subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma suggests that the Yangtze Block was previously located at the periphery of the Rodinia supercontinent.展开更多
The Yangtze River,with a length of approximately 6300 km,holds the distinction of being the largest river in East Asia that empties into the Pacific Ocean.Its formation is intricately linked to regional tectonic activ...The Yangtze River,with a length of approximately 6300 km,holds the distinction of being the largest river in East Asia that empties into the Pacific Ocean.Its formation is intricately linked to regional tectonic activity and climate fluctuations.However,the exact timeline for the formation of the Yangtze River remains elusive.This study investigates the provenance of the Late Cenozoic strata in the Wangjiang Basin,situated in the Lower Yangtze River,through the application of detrital zircon U-Pb dating.Seven sand samples were analyzed,leading to the identification of new U-Pb detrital zircon ages(n=577).Our study reveals that the sand materials found in the Pliocene gravel beds of the Anqing Formation originate predominantly from the Yangtze River.The findings of our study,along with the provenance tracing of boreholes in the Yangtze River Basin and the shelf sea in East China,provide compelling evidence for the continuous presence of the Yangtze River throughout the Pliocene period.The development of the Yangtze River during the Pliocene is intricately connected to both the tectonic adjustments occurring at the southeastern margin of the Tibetan Plateau and the intensification of the Asian Monsoon.展开更多
Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few ...Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.展开更多
Urban lakes are vital components of the modern urban water system and landscape design.They play an important role in the construction of urban ecological civilization.However,in recent years,the urban lake ecosystem ...Urban lakes are vital components of the modern urban water system and landscape design.They play an important role in the construction of urban ecological civilization.However,in recent years,the urban lake ecosystem has been increasingly degraded,especially with the frequent cyanobacteria blooms,which directly threatens the maintenance of ecosystem service function and sustainable urban development.In this study,several sedimentary cores were collected from Hudie Lake located in the Yangtze River Delta in China that had not been dredged for centuries.Using one of the sediment cores that spans the past 200 years,we reconstructed the long-term environmental changes and examined the driving mechanisms of both human activities and natural factors affecting the lake's dynamics.Our results indicated that,with the growth of the city,organic matter and nutrients in the lake had gradually increased.Notably,the significant increase in phosphorus had been a key factor driving cyanobacteria blooms in Hudie Lake.Since the 1960s,urban development and changes in land use around the lake had severely disturbed its natural habitats,leading to peak nutrient levels during the period from 2000 to 2010.展开更多
Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-w...Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.展开更多
The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the mos...The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the most crucial conservation approach involves the establishment and management of both in-situ and ex-situ nature reserves.Since the 1990s,seven nature reserves have been established in the middle and lower reaches of the Yangtze River,covering nearly one-third of its main stream.Additionally,two nature reserves,one in the Dongting Lake and another in the Poyang Lake,have been set up;and three ex-situ nature reserves have been established in three oxbows respectively in Hunan,Hubei,and Anhui provinces.Through measures such as improving the ecological environment quality within the reserves,regulating human activities,and conducting continuous monitoring,the finless porpoise population showed a slight increase in 2022 for the first time.The ex-situ population has continued to grow,with four individuals being released back into the main stream of the Yangtze River after undergoing reintroduction training in 2023.Based on the population development lasting for over three decades,and predictions of future ecological changes,orderly establishment and scientific management of nature reserves have played a key role in and will remain an important basis for the sustaining growth of the finless porpoise population.展开更多
Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Ya...Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Yangtze area is considered a potential target for shale gas exploration;however,the fundamental geological conditions of shale gas have not been studied.Based on the first whole-cored scientific drilling borehole(CSDP-2)in the SYSB,detailed tests involving petrology,organic geochemistry,and reservoir physical properties were conducted to evaluate the shale gas potential of the Lower Permian.The Lower Permian is dominated by organic-rich siliceous,clay,and clay-mixed shales.The average total organic carbon content is 5.99%,and the organic matter is mainly type Ⅱ_(1)−Ⅱ_(2),which has entered the high-over mature evolution stage.The pore types of organic-rich shales mainly include organic pores,dissolution pores,and intergranular pores,of which the meso-/macropores are well developed.The average porosity is 3.04%,and the total specific surface area and pore volume are 3.47 m^(2)/g and 7.21×10^(−3) cm^(3)/g,respectively.The average Langmuir volume obtained from the methane adsorption isotherms is 2.70 cm^(3)/g,and methane is mainly adsorbed in the meso-/macropores.The lower Permian shales are rich in methane as indicated by gas logging results,with an average content of 7.3%,which can reach up to 65.9%.A comparison of the study area with typical shale gas fields shows that the Lower Permian is brittle and shallowly buried and has a high potential for shale gas exploration and low-cost development.The depression areas of the SYSB are overlain by thick Mesozoic-Cenozoic sediments,show higher organic matter maturity,and may have greater shale gas potential.The shale gas exploration breakthrough of the study area is of great significance to ensure the energy supply of economically developed areas on the east China.展开更多
Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking wa...Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.展开更多
The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present ...The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.展开更多
基金support from the Natural Science Foundation of Jiangsu Province(Grant No.BK20240036)the National Natural Science Foundation of China(Grant Nos.U24A20515,22276099,and 22361162668)Guangxi Key Research and Development Program,China(Grant No.Guike AB24010074)。
文摘We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),organics(33%)constituted the largest fraction,followed by nitrate(30%),sulfate(18%),ammonium(15%),chloride(3%),and rBC(2%).Four organic aerosol(OA)subcomponents were identified,including two primary OA(POA)and two secondary OA(SOA).The less-oxidized SOA(LO-OOA)contributes the most to the total OA mass(59%).LO-OOA is tightly correlated with the tracer ion C_(2)H_(4)O_(2)^(+)from levoglucosan,and another aged biomass-burning derived species,K_(3)SO_(4)^(+),suggesting it was likely influenced by aged biomass-burning OA.Our study also revealed that fireworks during the Spring Festival have a detrimental impact on air quality,contributing to secondary formation and accumulation under static winter meteorological conditions,prolonging the pollution duration.Also,LO-OOA was found to have the strongest light-absorbing ability.Our results highlight that the light absorption of LO-OOA can mainly be attributed to the C_(x)H_(y)N^(+) family,increased with the double-bond equivalent value.The more-oxidized SOA(MO-OOA)exhibited a negligible light absorption and was strongly correlated with daytime photochemical processes,implying a light-bleaching effect.This study enhances our understanding of the regional contribution of biomass combustion and fireworks to PM_(1) pollution in Nanjing,a typical megacity in the Yangtze River Delta region,during winter,aiding in the development of strategies for long-term air quality improvement in the region.
基金National Natural Science Foundation of China,No.42207078CUG Scholar-Scientific Research Funds at China University of Geosciences(Wuhan),No.2022166+1 种基金China Scholarship Council,No.202306410026Opening Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,No.IWHR-SKL-KF202217。
文摘Wetlands play a critical role in the global environment.The Middle Yangtze River Basin(MYRB),known for its abundant wetland resources,has experienced notable changes resulting from the complex interplay of environmental factors.Therefore,we investigated the spatiotemporal characteristics of wetland ecological quality in the MYRB from 2001 to 2020.Utilizing the random forest(RF)regression algorithm and patch-generated land-use simulation(PLUS)model,we forecasted variations in wetland habitat quality and their determinants under the Shared Socioeconomic Pathway-Representative Concentration Pathway(SSPRCP)framework from 2035 to 2095.The main findings are as follows:(1)The RF algorithm was optimal for land-use and land-cover(LULC)classification in the MYRB from 2001 to 2020,when notable changes were observed in water bodies and buildings.However,the forested area exhibited an increase and decrease of 3.9%and 1.2%under the SSP1-2.6 and SSP5-8.5 scenarios,respectively,whereas farmland exhibited a diminishing trend.(2)Wetlands were primarily concentrated in the central and eastern MYRB,with counties in the southwest exhibiting superior ecological-environmental quality from 2001 to 2020.Notably,wetland coverage revealed significantly high level,significant changes,frequent but relatively minor changes under the SSP1-2.6,SSP2-4.5,and SSP 5-8.5 scenarios,respectively.(3)Regions with lower habitat quality were primarily concentrated in urbanized areas characterized by frequent human activities,indicating a clear degradation in habitat quality across different scenarios.In conclusion,we established a foundational framework for future investigations into the eco-hydrological processes and ecosystem quality of watersheds.
基金Under the auspices of the National Natural Science Foundation of China(No.42301470,42171389)。
文摘Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable development.This study analyzed the spatiotemporal evolution and landscape pattern change of construction land in the Yangtze River Delta(YRD)region from 1990 to 2018 by integrating Geographical Information System(GIS)spatial analysis and landscape pattern indices,and revealed its driving mechanism by XGBoost and SHapley Additive ex Planations(SHAP).Moreover,we compared the disparities in the core driving factors for construction land evolution in cities with diverse development orientations within the YRD region.Results show that:1)development intensity of construction land continued to increase from 7.54%in 1990 to 13.44%in 2018,primarily by occupying farmland.The landscape fragmentation of construction land in the YRD region decreased,and landscape dominance increased.Spatially,the eastern part of the YRD exhibits a high degree of spatial agglomeration of construction land,whereas the western part shows a high degree of fragmentation,revealing distinct spatial gradient differentiation characteristics.The landscape dominance of the construction land in the eastern region of the YRD is higher than that in the western and northern regions.2)Transportation and infrastructure exert the highest contribution rate on development intensity changes of construction land in the YRD.The industrial structure significantly influences the conversion of farmland to construction land.Additionally,infrastructure plays a crucial role in shaping the spatial agglomeration patterns of construction land.Population distribution is the dominant factor determining the regularity of the landscape shape of construction land.3)The core driving factors for the development intensity of construction land in central cities primarily lies in transportation,whereas for non-central cities,besides transportation,the year-end balance of per capita savings deposits of urban and rural residents also play a significant role.The area change of construction land occupying farmland in central and non-central cities is mainly driven by industrial structure and economic level,respectively.This study informs refined spatial optimization and regional high-quality integrated development.
基金supported by the Joint Funds of the National Natural Science Foundation of China(No.U21A2027)the New Cornerstone Science Foundation through the XPLORER PRIZE(2023-1033).
文摘This study focuses on the spatiotemporal distribution,urban-rural variations,and driving factors of ammonia Vertical Column Densities(VCDs)in China’s Yangtze River Delta region(YRD)from 2008 to 2020.Utilizing data from the Infrared Atmospheric Sounding Interfer-ometer(IASI),Generalized Additive Models(GAM),and the GEOS-Chem chemical transport model,we observed a significant increase of NH_(3)VCDs in the YRD between 2014 and 2020.The spatial distribution analysis revealed higher NH_(3)concentrations in the northern part of the YRD region,primarily due to lower precipitation,alkaline soil,and intensive agricul-tural activities.NH_(3)VCDs in the YRD region increased significantly(65.18%)from 2008 to 2020.The highest growth rate occurs in the summer,with an annual average growth rate of 7.2%during the period from 2014 to 2020.Agricultural emissions dominated NH_(3)VCDs during spring and summer,with high concentrations primarily located in the agricultural areas adjacent to densely populated urban zones.Regions within several large urban areas have been discovered to exhibit relatively stable variations in NH_(3)VCDs.The rise in NH_(3)VCDs within the YRD region was primarily driven by the reduction of acidic gases like SO_(2),as emphasized by GAM modeling and sensitivity tests using the GEOS-Chem model.The concentration changes of acidic gases contribute to over 80%of the interannual variations in NH_(3)VCDs.This emphasizes the crucial role of environmental policies targeting the reduction of these acidic gases.Effective emission control is urgent tomitigate environmental hazards and secondary particulate matter,especially in the northern YRD.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750000)the National Natural Science Foundation of China(Nos.52270012 and 52470018)the Ministry of Science and Technology of China(Nos.2022YFC3203705 and2021YFC3200904)。
文摘Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
基金supported by the National Natural Science Foundation of China(No.42075177)the National Key Research and Development Program of China(No.2017YFC0210003).
文摘Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological variables.The results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,respectively.The meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive areas.Based on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,respectively.The spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic conditions.The central urban agglomeration north and south of the YRD was particularly susceptible to local pollution.Among the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.
文摘Tour Overview.“Yangtze River Fantasy Tour-Charm of the Yangtze”is a carefully crafted 6-night,7-day journey for you to fully experience the endless charm of China's Yangtze River.On this trip,tourists will embark on a top luxury cruise ship on China,s inland rivers,sailing through the Yangtze River,enjoying comfort and luxury.The modern design and complete facilities of the cruise ship not only provide first-class accommodation but also offer a variety of onboard entertainment activities,filling your journey with laughter and joy.
基金supported by the National Natural Science Foundation of China(No.U2040210).
文摘Interaction between the Yangtze River and its tributaries in the Three Gorges Reservoir has an important influence on tributary algal blooms.Taking the Xiaojiang River as a typical tributary,a binary mixing model used stable isotopes of hydrogen and oxygen to quantitatively analyze the water contribution and nutrient source structure of the tributary backwater area.Results showed that the isotope content(δD:−54.7‰,δ^(18)O−7.8‰)in the Yangtze River was higher than that in the tributaries(δD:−74.2‰,δ^(18)O−17.0‰)in the non-flood season and lower than that in the tributaries in the flood season.The Yangtze River contributed more than 50%water volume of the tributary backwater area in the non-flood season.The total nitrogen and total phosphorus concentrations in the backwater area were estimated based on water contribution ratio,and the results were in good agreement with the monitoring results.Load estimation showed that the nitrogen and phosphorus contribution ratio of the Yangtze River to the tributary backwater area was approximately 40%-80%in the non-flood season,and approximately 20%-40%in the flood season,on average.This study showed that the interaction between the Xiaojiang River and the Yangtze River is significant,and that Yangtze River recharge is an important source of nutrients in the Xiaojiang backwater area,which may play a driving role in Xiaojiang River algal blooms.
基金supported by the National Key Research and Development Program of China(Nos.2021YFC3200801 and 2021YFC3200804).
文摘Synthetic phenolic antioxidants(SPAs)and parabens,particularly the high-molecularweight(HMW)SPAs and long alkyl chain(LAC)parabens with higher environmental persistence and toxicities,are widely produced and applied worldwide.However,their occurrence and potential risks in aquatic environments remain largely unknown.This work investigated 11 HMW SPAs and 3 LAC parabens in the river and treated industrial wastewater samples along the Yangtze River,the largest river and most important source water in China.For convenience of comparison,6 short alkyl chain(SAC)parabens were also included.In 15 industrial wastewater treatment plant effluents(effluent-IWTPs)and 34 surface water monitoring sections along the river,19 out of 20 target compounds were detected with total concentrations(TCs)from 152.5 to 1955.5 ng/L and 141.3 to 1364.9 ng/L in effluent-IWTPs and surface water,respectively.HMW SPAs 1,3,5-tris-[(3,5-di–tert–butyl–4-hydroxyphenyl)methyl]-1,3,5-triazinane-2,4,6-trione(AO3114)and octadecyl 3-(3,5-di–tert–butyl–4-hydroxyphenyl)propionate(AO1076)were the dominant ones.HMWSPAs bis(3–tert–butyl–4–hydroxy-5-methylphenyl)propionate(AO245)and 4,4'-sulfanediylbis(2–tert–butyl–5-methylphenol)(AO-TBM6)and SAC parabens propylparaben(PrP)and butylparaben(BuP)posed medium to high potential ecological risks in 27 surface water monitoring sections.Additionally,AO-TBM6 also exhibited potential health risks in 2 out of 11 drinking water sources.Though the ecotoxicity data are very limited,the ubiquitous presence of the LAC parabens including hexylparaben(HeP)and octylparaben(OcP)in surface water should be of concern since these compounds usually exhibit stronger estrogen potencies than the SAC ones.Finally,kernel density analysis revealed that regulation of industrial discharges is necessary to mitigate the HMW SPA and paraben contamination.
文摘Welcome to the China Travel column!This section is dedicated to providing both Chinese and international readers with a comprehensive platform to explore China's rich cultural and tourism resources.Here,we will present China's natural landscapes,historic sites,folk customs,and modern developments in both Chinese and English.
基金jointly supported financially by the National Natural Science Foundation of China(No.41603040)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2023-JC-YB-239)Fundamental Research Funds for the Central Universities(S202310710204)。
文摘The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the mineralization-related mafic-ultramafic rocks,the intermediate-acid intrusive rocks are also exposed in the mining area,which is of great significance for the understanding the Neoproterozoic tectonic evolution of the Yangtze Block,but studies on these intermediate-acid rocks are scarce.The Bijigou mafic-ultramafic layered intrusion is surrounded by granite and cut by syenite veins.Here,we report new zircon U-Pb ages,Lu-Hf isotope composition and bulk rock geochemical data of the Bijigou syenite vein and wall-rock granite in the northwestern margin of the Yangtze Block.Laser ablation inductively coupled plasma mass spectrometry(LAICP-MS)zircon U-Pb dating results show that the Bijigou syenite vein and wall-rock granite formed at 770±3.5 Ma(MSWD=0.17,n=28)and 810±4 Ma(MSWD=0.84,n=26),respectively.The zirconεHf(t)values of the syenite veins range from+1.52 to+5.33(average of+3.05),combined with its high potassium contents,negative Nb–Ta anomalies and positive Pb anomalies,suggesting that they may have originated from mantle-derived basaltic magma,which was modified by materials from subducting oceanic slab.The zirconεHf(t)and T_(DM2)ages of the wall-rock granite range from+0.71 to+5.71(average+3.06)and 1344 to 1659 Ma(average 1519 Ma),respectively,indicating that the granite was produced by partial melting of juvenile crust.The geochemical characteristics of the Bijigou syenite and granite indicate that they were formed in a continental margin arc setting.Thus,combined with previous studies,it suggests that there was a major subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma,and the magmatism in the Hannan massif was divided into two episodes:(1)early magmatism(824-790 Ma),such as the Bijigou,Hongmiaozhen and Huangguanzhen granitoids,was derived from partial melting of the juvenile or pre-existing crust in a continental arc setting;(2)later magmatism(789-718 Ma),including Bijigou syenite,Wudumen,Erliba and Zushidian granitoids,formed in a subduction-related back-arc extensional environment.The long-term subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma suggests that the Yangtze Block was previously located at the periphery of the Rodinia supercontinent.
基金supported by the National Natural Science Foundation of China(Nos.42030305W2411033)Research Foundation of Chutian Scholars Program of Hubei Province(No.8210403)。
文摘The Yangtze River,with a length of approximately 6300 km,holds the distinction of being the largest river in East Asia that empties into the Pacific Ocean.Its formation is intricately linked to regional tectonic activity and climate fluctuations.However,the exact timeline for the formation of the Yangtze River remains elusive.This study investigates the provenance of the Late Cenozoic strata in the Wangjiang Basin,situated in the Lower Yangtze River,through the application of detrital zircon U-Pb dating.Seven sand samples were analyzed,leading to the identification of new U-Pb detrital zircon ages(n=577).Our study reveals that the sand materials found in the Pliocene gravel beds of the Anqing Formation originate predominantly from the Yangtze River.The findings of our study,along with the provenance tracing of boreholes in the Yangtze River Basin and the shelf sea in East China,provide compelling evidence for the continuous presence of the Yangtze River throughout the Pliocene period.The development of the Yangtze River during the Pliocene is intricately connected to both the tectonic adjustments occurring at the southeastern margin of the Tibetan Plateau and the intensification of the Asian Monsoon.
文摘Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.
基金State Key Laboratory of Lake and Watershed Science for Water Security,No.2024SKL016National Natural Science Foundation of China,No.42002204,No.42373060+1 种基金Innovative Training Program for University Students,No.2024219,No.2024224Jiangsu Provincial Government Scholarship Program for Studying Abroad,No.2024-075。
文摘Urban lakes are vital components of the modern urban water system and landscape design.They play an important role in the construction of urban ecological civilization.However,in recent years,the urban lake ecosystem has been increasingly degraded,especially with the frequent cyanobacteria blooms,which directly threatens the maintenance of ecosystem service function and sustainable urban development.In this study,several sedimentary cores were collected from Hudie Lake located in the Yangtze River Delta in China that had not been dredged for centuries.Using one of the sediment cores that spans the past 200 years,we reconstructed the long-term environmental changes and examined the driving mechanisms of both human activities and natural factors affecting the lake's dynamics.Our results indicated that,with the growth of the city,organic matter and nutrients in the lake had gradually increased.Notably,the significant increase in phosphorus had been a key factor driving cyanobacteria blooms in Hudie Lake.Since the 1960s,urban development and changes in land use around the lake had severely disturbed its natural habitats,leading to peak nutrient levels during the period from 2000 to 2010.
基金supported by the National Natural Science Foundation of China(Nos.42301029,42371354)the Scientific Research Start-up Fund for New Young Faculty,China University of Geosciences,Wuhan(No.CUGXQN2307)China Meteorological Administration Innovation and Development Project(No.CXFZ2023J051).
文摘Compound extreme climate events may profoundly affect human activity in the Yangtze River Basin.This study analyzed the long-term spatiotemporal distribution characteristics of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin using multi-period historical observation data and future scenario climate model data.It also examined the changes in population exposure to compound extreme climate events in the basin and their driving factors by combining population statistics and forecast data.The results show that the occurrence days of compound heatwave-drought and heatwave-waterlogging events in the Yangtze River Basin have shown a significant upward trend both in historical periods and future scenarios,accompanied by a marked expansion in the affected areas.Compared to historical periods,population exposure in the Yangtze River Basin under future scenarios is expected to increase by 1.5–2 times,primarily concentrated in the key urban areas of the basin.The main factors driving the changes in population exposure are the increased frequency of extreme climate events and population decline in future scenarios.These findings provide scientific evidence for early mitigation of meteorological disasters in the Yangtze River Basin.
基金supported by the National Natural Science Foundation of China(42225604,31500456,31430080)the 2023 Strategic Consultation Project of the Chinese National Committee for Man and the Biosphere,the National Key Programme of Research and Development of Ministry of Science and Technology of China(2022YFF1301603)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23040403).
文摘The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)is distributed in the main stream of the middle and lower reaches of the Yangtze River,as well as in Dongting and Poyang lakes.Currently,the most crucial conservation approach involves the establishment and management of both in-situ and ex-situ nature reserves.Since the 1990s,seven nature reserves have been established in the middle and lower reaches of the Yangtze River,covering nearly one-third of its main stream.Additionally,two nature reserves,one in the Dongting Lake and another in the Poyang Lake,have been set up;and three ex-situ nature reserves have been established in three oxbows respectively in Hunan,Hubei,and Anhui provinces.Through measures such as improving the ecological environment quality within the reserves,regulating human activities,and conducting continuous monitoring,the finless porpoise population showed a slight increase in 2022 for the first time.The ex-situ population has continued to grow,with four individuals being released back into the main stream of the Yangtze River after undergoing reintroduction training in 2023.Based on the population development lasting for over three decades,and predictions of future ecological changes,orderly establishment and scientific management of nature reserves have played a key role in and will remain an important basis for the sustaining growth of the finless porpoise population.
基金supported by the Natural Science Foundation of Shandong Province(ZR2023MD112)financially supported by Laoshan Laboratory(LSKJ202203401).
文摘Shale gas is abundant in the Paleozoic of the Yangtze Platform,and several high-yield shale gas fields have been built in the Upper Yangtze Platform,China.The Permian of the South Yellow Sea Basin(SYSB)in the Lower Yangtze area is considered a potential target for shale gas exploration;however,the fundamental geological conditions of shale gas have not been studied.Based on the first whole-cored scientific drilling borehole(CSDP-2)in the SYSB,detailed tests involving petrology,organic geochemistry,and reservoir physical properties were conducted to evaluate the shale gas potential of the Lower Permian.The Lower Permian is dominated by organic-rich siliceous,clay,and clay-mixed shales.The average total organic carbon content is 5.99%,and the organic matter is mainly type Ⅱ_(1)−Ⅱ_(2),which has entered the high-over mature evolution stage.The pore types of organic-rich shales mainly include organic pores,dissolution pores,and intergranular pores,of which the meso-/macropores are well developed.The average porosity is 3.04%,and the total specific surface area and pore volume are 3.47 m^(2)/g and 7.21×10^(−3) cm^(3)/g,respectively.The average Langmuir volume obtained from the methane adsorption isotherms is 2.70 cm^(3)/g,and methane is mainly adsorbed in the meso-/macropores.The lower Permian shales are rich in methane as indicated by gas logging results,with an average content of 7.3%,which can reach up to 65.9%.A comparison of the study area with typical shale gas fields shows that the Lower Permian is brittle and shallowly buried and has a high potential for shale gas exploration and low-cost development.The depression areas of the SYSB are overlain by thick Mesozoic-Cenozoic sediments,show higher organic matter maturity,and may have greater shale gas potential.The shale gas exploration breakthrough of the study area is of great significance to ensure the energy supply of economically developed areas on the east China.
基金supported by the National Key Research and Development Program of China(No.2019YFD1100203).
文摘Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF2023S1A5A2A01077716)。
文摘The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.
