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Inter-annual variations of dissolved oxygen and hypoxia off the northern Changjiang River(Yangtze River) Estuary in summer from 1997 to 2014
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作者 Anqi Liu Feng Zhou +6 位作者 Xiao Ma Qiang Zhao Guanghong Liao Yuntao Zhou Di Tian Xiaobo Ni Ruibin Ding 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期119-130,共12页
Hypoxia off the Changjiang River Estuary has been the subject of much attention,yet systematic observations have been lacking,resulting in a lack of knowledge regarding its long-term change and drivers.By revisiting t... Hypoxia off the Changjiang River Estuary has been the subject of much attention,yet systematic observations have been lacking,resulting in a lack of knowledge regarding its long-term change and drivers.By revisiting the repeated surveys of dissolved oxygen(DO) and other relevant hydrographic parameters along the section from the Changjiang River Estuary to the Jeju-do in the summer from 1997 to 2014,rather different trends were revealed for the dual low-DO cores.The nearshore low-DO core,located close to the river mouth and relatively stable,shows that hypoxia has become more severe with the lowest DO descen ding at a rate of -0.07 mg/(L·a) and the thickness of low-DO zone rising at a rate of 0.43 m/a.The offshore core,centered around 40-m isobath but moving back and forth between 123.5°-125°E,shows large fluctuations in the minimum DO concentration,with the thickness of low-DO zone falling at a rate of -1.55 m/a.The probable factors affecting the minimum DO concentration in the two regions also vary.In the nearshore region,the decreasing minimum DO is driven by the increase in both stratification and primary productivity,with the enhanced extension of the Changjiang River Diluted Water(CDW) strengthening stratification.In the offshore region,the fluctuating trend of the minimum DO concentration indicates that both DO loss and DO supplement are distinct.The DO loss is primarily attributed to bottom apparent oxygen utilization caused by the organic matter decay and is also relevant to the advection of low-DO water from the nearshore region.The DO supplement is primarily due to weakened stratification.Our analysis also shows that the minimum DO concentration in the nearshore region was extremely low in 1998,2003,2007 and 2010,related to El Ni?o signal in these summers. 展开更多
关键词 dissolved oxygen low-DO changjiang River Estuary interannual variations DUAL-CORE
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Morphological comparison and molecular marker screening of three Skeletonema species found in Changjiang(Yangtze)River Basin
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作者 Jingwen HU Yuxin YI +4 位作者 Zhengxin YANG John Patrick KOCIOLEK Pan YU Quanxi WANG Qingmin YOU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第3期923-942,共20页
In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River ... In our recent investigations of diatom diversity,we studied three species,namely,Skeletonema costatum,Skeletonema subsalsum,and Skeletonema potamos.Although they have been found frequently in Changjiang(Yangtze)River Basin,their morphological and molecular identification is difficult in taxonomy.Therefore,to integrate morphological and molecular biological approaches,we compared systematically their morphological characters and performed phylogenetic analysis.Twelve strains of Skeletonema were collected and isolated from Shanghai and Jiangsu,China,and their morphological characteristics were examined by light microscopy(LM)and the scanning electron microscopy(SEM).Based on morphological comparison,we determined that S.potamos is easy to distinguish from the other two species.The heavily silicified areolae,undulated or cleft distal ends of terminal fultoportula processes(TFPPs),absence of basal pores of fultoportula processes(FPPs),the rootlike protrusions of FPPs,and no interlocking connection are the stable characteristics that can be used to identify S.potamos.However,there are only two features that can distinguish S.costatum from S.subsalsum,namely the location of terminal rimoportulae(TRPs)and the distal shape of TFPPs.In addition,we amplified and sequenced nine common genetic markers from the strains,from which 101 sequences were obtained,constructed phylogenetic trees based on the nine genes and evaluated that seven genes can be used to identify S.potamos,and revealed that S.subsalsum is the closest known relative of S.costatum,and only ATP synthetase beta-subunit gene(atp B)is able to distinguish them from each other,which strongly support that it is an effective molecular marker for Skeletonema.This work provided a theoretical basis for the taxonomic study of Skeletonema. 展开更多
关键词 SKELETONEMA changjiang River morphological change distinguishing morphological characteristics molecular marker
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Effects of phosphorus limitation on sinking velocities of phytoplankton during summer in the Changjiang River Estuary
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作者 Xinchi You Qiang Hao +6 位作者 Jie Zhu Wei Zhang Haiyan Jin Dewang Li Huanhong Ji Yu Ke Feng Zhou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期131-141,共11页
The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted ... The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted during the summer of 2022 in the Changjiang River(Yangtze River) Estuary(CJE) and its adjacent waters.The settling column method was employed to measure the sinking velocity(SV) of different size fractions of phytoplankton at the surface of the sea and to analyze their environmental control mechanisms.The findings reveal significant spatial variation in phytoplankton SV(-0.55-2.41 m/d) within the CJE.High-speed sinking was predominantly observed in phosphate-depleted regions beyond the CJE front.At the same time,an upward trend was more commonly observed in the phosphate-rich regions near the CJE mouth.The SV ranges for different sizefractionated phytoplankton,including micro-(>20 μm),nano-(2-20 μm),and picophytoplankton(0.7-2 μm),were-0.50-4.74 m/d,-1.04-1.59 m/d,and-1.24-1.65 m/d,respectively.Correlation analysis revealed a significant negative correlation between SV and dissolved inorganic phosphorus(DIP),implying that the influence of DIP contributes to SV.The variations in phytoplankton alkaline phosphatase activity suggested a significant increase in SV across all size fractions in the event of phosphorus limitation.Phytoplankton communities with limited photo synthetic capacity(maximum photochemical efficience,Fv/Fm <0.3) were found to have higher SV than that of communities with strong capacity,suggesting a link between sinking and alterations in physiological conditions due to phosphate depletion.The findings from the in situ phosphate enrichment experiments confirmed a marked decrease in SV following phosphate supplementation.These findings suggest that phosphorus limitation is the primary driver of elevated SV in the CJE.This study enhances the comprehension of the potential mechanisms underlying hypoxic zone formation in the CJE,providing novel insights into how nearshore eutrophication influences organic carbon migration. 展开更多
关键词 PHYTOPLANKTON sinking velocity changjiang River Estuary phosphorus limitation alkaline phosphatase
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Responding of zooplankton to environmental factor changes in the Changjiang River estuarine regions in spring-summer from 2016 to 2020
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作者 Jieqing YANG Dongrong ZHANG +4 位作者 Yuange CHEN Longling OUYANG Yangyang YANG Jin ZHOU Yunrong SHI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第2期544-559,共16页
The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Ther... The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence. 展开更多
关键词 changjiang River estuary(CRE) ZOOPLANKTON dominant species ecological group environmental factor CO-EXISTENCE
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Coastal hypoxia response to the coupling of catastrophic flood,extreme marine heatwave and typhoon:a case study off the Changjiang River Estuary in summer 2020
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作者 Xiao Ma Qicheng Meng +8 位作者 Dewang Li Yuanli Zhu Xiaobo Ni Dingyong Zeng Di Tian Ting Huang Zhihao Jiang Haiyan Jin Feng Zhou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期107-118,共12页
Massive bodies of low-oxygen bottom waters are found in coastal areas worldwide,which are detrimental to coastal ecosystems.In summer 2020,the response of coastal hypoxia to extreme weather events,including a catastro... Massive bodies of low-oxygen bottom waters are found in coastal areas worldwide,which are detrimental to coastal ecosystems.In summer 2020,the response of coastal hypoxia to extreme weather events,including a catastrophic flooding,an extreme marine heatwave,and Typhoon Bavi,is investigated based on multiple satellite,four cruises,and mooring observations.The extensive fan-shaped hypoxia zone presents significant northward extension during July-September 2020,and is estimated as large as 13 000 km^(2) with rather low oxygen minimum(0.42 mg/L) during its peak in 28-30 August.This severe hypoxia is attributed to the persistent strong stratification,which is indicated by flood-induced larger amount of riverine freshwater input and subsequent marine heatwave off the Changjiang River Estuary.Moreover,the Typhoon Bavi has limited effect on the marine heatwave and coastal hypoxia in summer 2020. 展开更多
关键词 coastal hypoxia changjiang River Estuary extreme weather events seasonal evolution
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Spatiotemporal changes of biogenic elements in the Changjiang River Estuary and adjacent waters in summer over the last decade 被引量:2
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作者 Lu Yang Yujia Zhang +3 位作者 Xiaoli Wang Qiulu Wang Long He Xiao Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第1期83-90,共8页
The long-term spatiotemporal changes of surface biogenic elements in the Changjiang River Estuary and adjacent waters during the summer of 2008–2016 were analyzed in this study.The concentrations of dissolved inorgan... The long-term spatiotemporal changes of surface biogenic elements in the Changjiang River Estuary and adjacent waters during the summer of 2008–2016 were analyzed in this study.The concentrations of dissolved inorganic nitrogen(DIN),soluble reactive phosphate(PO_(4)^(3−))and silicate(SiO_(3)^(2−))were generally stable,with a slight decrease of DIN and PO_(4)^(3−),and a slight increase of SiO_(3)^(2−),which mainly occurred in the estuarine waters.The grey correlation analysis was carried out between biogenic elements and chlorophyll a(Chl-a).Results showed that compared with the absolute values of biogenic elements,the correlations between the concentration ratio of nitrogen to phosphorus(N/P),ratio of silicon to nitrogen(Si/N)and Chl-a were closer,indicating the important influence on phytoplankton by the structure of biogenic elements.The study area was generally in a state of potential P limitation,and could have potential impact on the phytoplankton community,triggering the shift of red tide dominant species from diatoms to dinoflagellates. 展开更多
关键词 changjiang River Estuary biogenic elements spatiotemporal changes
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数字孪生驱动的长江流域干旱防御平台设计与开发 被引量:1
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作者 李喆 向大享 +1 位作者 陈喆 崔长露 《长江科学院院报》 CSCD 北大核心 2024年第8期180-188,共9页
在全球气候变化的背景下,长江流域发生了多次严重的高温干旱灾害,流域抗旱管理面临着旱情监测告警效率较低、旱灾预报预警精度不高、抗旱预案推演能力不足等瓶颈,迫切需要开展数字化转型。从长江流域抗旱减灾业务管理和“四预”应用需... 在全球气候变化的背景下,长江流域发生了多次严重的高温干旱灾害,流域抗旱管理面临着旱情监测告警效率较低、旱灾预报预警精度不高、抗旱预案推演能力不足等瓶颈,迫切需要开展数字化转型。从长江流域抗旱减灾业务管理和“四预”应用需求出发,基于智慧水利和数字孪生建设的总体要求,综合运用WebGL、GIS等技术,建立了干旱防御数字孪生平台,研发了遥感干旱监测评估、干旱专业模型动态加载、旱警水位超限预警、抗旱预案可视化等关键技术,初步实现了“预报-预警-预演-预案”全链条贯通业务应用,切实提升了长江流域抗旱管理智能化、精细化水平,为流域干旱防灾减灾提供了技术支撑。 展开更多
关键词 长江流域 干旱防御信息平台 数字孪生 四预
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海温异常对长江流域夏季典型旱涝的影响研究 被引量:1
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作者 张灵 熊开国 +1 位作者 郭广芬 张俊 《人民长江》 北大核心 2024年第4期118-124,共7页
为研究长江流域夏季旱涝特征及其与海温异常之间的关联性,基于中国326个气象站降水量、NCEP/NCAR再分析资料等,采用合成分析、EOF分解等方法,分析了长江流域夏季典型旱涝年的降水分布、同期大气环流及前期海温特征,并以2018年为例,初步... 为研究长江流域夏季旱涝特征及其与海温异常之间的关联性,基于中国326个气象站降水量、NCEP/NCAR再分析资料等,采用合成分析、EOF分解等方法,分析了长江流域夏季典型旱涝年的降水分布、同期大气环流及前期海温特征,并以2018年为例,初步揭示了2018年前期海温异常对大气环流的可能影响。结果表明:①长江流域夏季典型旱年,仅嘉陵江和岷沱江会表现出局部偏涝,全国为典型的Ⅰ类雨型,多雨区位于黄河流域及以北地区。前期冬季赤道太平洋表现出类拉尼娜的东冷西暖分布,同时黑潮区海温偏低,西风漂流区海温偏暖。受多海域协同作用,同期欧亚环流场上自西北向东南呈现出“+-+”三极型分布,东亚地区为自北向南“-+-”的EAP负位相。长江流域典型涝年,全国多为典型的Ⅱ类和Ⅲ类雨型,环流及海温呈现出相反特征。②2018年为典型的长江中下游偏旱年,仅在岷沱江降水偏多近3成,为历史第4多,与长江流域夏季降水的主模态正位相类似,解释方差达24%。③2018年前冬出现弱拉尼娜、春末夏初西风漂流区异常偏暖、NAT异常正位相,三者共同作用,使得东亚副热带西风急流偏北,东亚沿岸出现EAP负位相,大陆热低压明显偏强,东亚夏季风为1961年以来最强,同时副高脊线最北,造成夏季降水主雨带北推至华北、西北地区,岷沱江、嘉陵江异常多,而长江中下游异常少,为典型的Ⅰ类雨型。研究成果可为长江流域旱涝预测、水资源调度提供参考。 展开更多
关键词 夏季典型旱涝 海温异常 Ⅰ类雨型 拉尼娜 西风漂流区 长江流域
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Diel,seasonal,and annual variations of fish assemblages in intertidal creeks of the Changjiang River estuary
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作者 Jiayi FAN Jiasheng YANG +1 位作者 Yuanwen HE Xiaodong JIANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第5期1849-1863,共15页
The use patterns of salt marsh habitats by fish assemblages were investigated in two welldeveloped intertidal creeks in the Changjiang(Yangtze)River estuary on spatial and temporal scales.Samples were collected using ... The use patterns of salt marsh habitats by fish assemblages were investigated in two welldeveloped intertidal creeks in the Changjiang(Yangtze)River estuary on spatial and temporal scales.Samples were collected using fyke nets at two sites during day and night in each season throughout four years.Notable changes in fish assemblages were detected over seasonal and interannual cycles,with many more marine species present in winter assemblages,whereas freshwater and estuarine species characterized the other seasonal samplings.The appearance of catadromous species in intertidal creeks mainly depended upon their specific physiological requirements,such as spawning migration.No significant diel shifts were observed in fish assemblages.This diel pattern may be a combined consequence of avian predation pressure and other drivers(i.e.,inherent living behaviors,food availability,and predation by piscivorous fishes).The spatial difference in fish community was insignificant even though the two intertidal creeks were different in size.Intertidal creeks with different size could possess similar ecological value for fish fauna.Redundancy analysis(RDA)showed that biological factors exerted greater effects on fish assemblages than physical variables.Temporal variations were strongly facilitated by food availability,but negatively impacted by avian predation.Salinity,water temperature,and river runoff had weak influence on temporal variations of fish communities.The lengthfrequency distribution showed that the fish collected in these two sites mainly consisted of young-of-year and juvenile fish,which confirmed that the creeks provided important nursery and forage roles in the process of fish ontogenetic development.Further,we proposed that salt marsh conservation management should be equally applied to all well-developed intertidal creeks regardless of creek size. 展开更多
关键词 FISH temporal variation intertidal creeks changjiang(Yangtze)River estuary
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Diatom-based dissolved inorganic nitrogen reconstruction in the Changjiang River estuary and its adjacent areas
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作者 Xin FAN Fangjin CHENG +1 位作者 Zhiming YU Xiuxian SONG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1464-1480,共17页
A five-component weighted average partial least squares(WA-PLS)calibration model was developed by analysing diatom assemblages in 34 surface sediment samples(collected in 2015)from the Changjiang River estuary(CRE)and... A five-component weighted average partial least squares(WA-PLS)calibration model was developed by analysing diatom assemblages in 34 surface sediment samples(collected in 2015)from the Changjiang River estuary(CRE)and its adjacent areas to infer dissolved inorganic nitrogen(DIN)concentrations.Eighteen additional sets of surface sediment diatoms and corresponding upper water DIN data(collected in 2012)were used to evaluate the accuracy of the model,and the relationship between observed and diatom-inferred DIN(DI-DIN)values(R2=0.85)illustrated the strong performance of the transfer function,indicating that precise reconstructions of former DIN are possible.The diatom-DIN transfer function was applied to the diatom record from a sediment core DH8-2(1962‒2012)collected in the Fujian-Zhejiang area south of the CRE.The reconstruction based on the DI-DIN model showed a significant DIN increase from 1962-2012,reflecting the influence of human activities on the very large increase in eutrophication.Three distinct periods can be seen from the changes in DIN and diatom taxa.In the 1962-1972 period,the DIN content was relatively low,with an average of 5.94μmol/L,and more than 80%of the diatom species identified were benthic taxa.In the 1972-2004 period,as the impact of human activities intensified,large nutrient inputs caused the DIN content to increase,with an average of 8.25μmol/L.The nutrient inputs also caused a significant change in the nutrient components and a distinct increase in small planktonic taxa.In the 2004-2012 period,the DIN content continued to rise,fluctuating at approximately 10μmol/L.A continuous increase in the frequency of planktonic taxa(up to 65.48%)indicated that eutrophication was further intensified,which was confirmed by the transformation from diatom-induced red tide to dinoflagellate-induced red tide during this period. 展开更多
关键词 changjiang River estuary dissolved inorganic nitrogen(DIN)reconstruction DIATOMS transfer function
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Prokaryotic diversity and community composition in the surface sediments of the Changjiang River Estuary in summer
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作者 Changfeng Qu Xixi Wang +5 位作者 Liping Zhang Huamao Yuan Xuegang Li Ning Li Fushan Chen Jinlai Miao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第9期113-124,共12页
Microorganisms are fundamental for the functioning of marine ecosystems and are involved in the decomposition of organic matter, transformation of nutrients and circulation of biologically-important chemicals. Based o... Microorganisms are fundamental for the functioning of marine ecosystems and are involved in the decomposition of organic matter, transformation of nutrients and circulation of biologically-important chemicals. Based on the complexity of the natural geographic characteristics of the Changjiang River Estuary, the geographic distribution of sedimentary microorganisms and the causes of this distribution are largely unexplored. In this work, the surface sediment samples from the adjacent sea area of the Changjiang River Estuary were collected. Their prokaryotic diversity was examined by high-throughput sequencing technology, and the environmental factors of the bacterial community were investigated. The results indicated that the distribution of prokaryotic communities in the sediments of the study areas showed obvious spatial heterogeneity. The sampling sequences divided the sample regions into three distinct clusters. Each geographic region had a unique community structure, although Proteobacteria, Bacteroidota, Desulfobacterota, Acidobacteriota, and Actinobacteriota all existed in these three branches. Canonical correspondence analysis demonstrated that prokaryotic diversity and community distribution were significantly correlated with the geographic location of sediment, seawater depth, and in particular, nutrient content(e.g., total phosphorus, total organic carbon and dissolved oxygen). Moreover, it was found for the first time that the metal ions obviously affected the composition and distribution of the prokaryotic community in this area. In general, this work provides new insights into the structural characteristics and driving factors of prokaryotic communities under the background of the ever-changing Changjiang River Estuary. 展开更多
关键词 prokaryotic diversity 16S rRNA gene geophysicochemical factors high-throughput sequencing(HTS) changjiang River Estuary
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Vertical structure of tidal currents in the Xuliujing Section of Changjiang River Estuary
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作者 Zhigao Chen Ya Ban +2 位作者 Xiaoye Chen Dajun Li Shengping Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第2期44-55,共12页
Three long-term fixed acoustic Doppler current profilers were first used for investigating the vertical structure of tidal currents in Xuliujing Section of Changjiang River Estuary.Moreover,three different periods(spr... Three long-term fixed acoustic Doppler current profilers were first used for investigating the vertical structure of tidal currents in Xuliujing Section of Changjiang River Estuary.Moreover,three different periods(spring,summer and fall)were also considered for investigating seasonal variations.The semi-diurnal tides were the most energetic,with along-channel speed of up to 80 cm/s for M_(2)constituent,which dominates at all stations with percent energy up to 65%–75%during seasons.The shape of tidal ellipses of the most energetic semi-diurnal constituent M_(2)showed obvious polarization of the flow paralleling to the riverbank,with the minor semi-axis being generally less than 20%of the major one.The maximum velocity of mean current is appeared in top layers at all the three stations,and the velocity decreased with the depth.The seasonal variations of direction are also observed,which is probably caused by complex local topography since the erosion and deposition in riverbed.Observed vertical variation of four parameters of M_(2)ellipses,agreed well with the optimally fit frictional solutions in top and middle layers.However,there was an obvious difference between frictional model and observed data in the lower water column.Discrepancies are probably on account of stratification,which strengthens in summer and fall due to the freshening influence of the Changjiang River Estuary outflow. 展开更多
关键词 vertical structure seasonal variations tidal current mean current acoustic Doppler current profiler changjiang River Estuary
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2016—2020年长江科学院发表的科技论文被SCI、EI和CPCI收录情况分析
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作者 聂文 陈元明 +1 位作者 沈晓莹 文振兴 《长江科学院院报》 CSCD 北大核心 2024年第2期198-202,共5页
利用SCI、EI和CPCI三大索引数据库对2016—2020年长江科学院所发表论文进行检索统计,运用文献计量法,从所收录论文的数量、专业、著者、作者群分布情况包括作者群年龄、学历、职称等方面进行统计、归纳和分析,并与前5 a统计数据比较,从... 利用SCI、EI和CPCI三大索引数据库对2016—2020年长江科学院所发表论文进行检索统计,运用文献计量法,从所收录论文的数量、专业、著者、作者群分布情况包括作者群年龄、学历、职称等方面进行统计、归纳和分析,并与前5 a统计数据比较,从产出论文这一侧面了解和反映长江科学院近几年来科研、专业和人才结构情况:科研实力和国际影响力得到较大增强,在保持传统专业科研实力的同时,新兴专业的科研实力也迅速提升,对外合作加强,拥有较高层次的科研人才队伍且趋于年轻化。研究结果可为长江科学院学科建设和科研绩效评估提供数据参考。 展开更多
关键词 论文收录 SCI EI CPCI 长江科学院 文献计量法 科学评估
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新情势下长江河口南槽河床冲淤演变特征
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作者 左书华 赵德招 +2 位作者 谢华亮 赵张益 杨华 《海洋地质前沿》 CSCD 北大核心 2024年第1期44-54,共11页
随着长江流域来沙的锐减、河口涉水工程的建设、生态环境保护力度的加大和通航环境的高效利用,长江口河势将面临着新一轮的调整。以长江口南槽河床冲淤演变为研究对象,采用河床演变分析的方法对南槽近十年来多次水下地形和航道水深数据... 随着长江流域来沙的锐减、河口涉水工程的建设、生态环境保护力度的加大和通航环境的高效利用,长江口河势将面临着新一轮的调整。以长江口南槽河床冲淤演变为研究对象,采用河床演变分析的方法对南槽近十年来多次水下地形和航道水深数据进行了分析,并对南槽航道治理一期工程效果进行了讨论。结果表明:2010-2018年,南槽主槽整体呈冲刷态势,江亚南沙头部窜沟冲刷发展,沙尾冲刷下延;2018年至今,江亚南沙头部窜沟由冲刷环境转化为淤积环境,其他区域冲淤形势基本未变;南槽断面主槽形态总体稳定,在主槽总体冲刷背景下,“拦门沙”逐渐被削平,加上南槽航道治理一期工程的作用,南槽6 m以深河槽容积明显扩大,且保持较好的稳定性。近期南槽河势变化是流域来水来沙和河口自然、人类活动影响的综合结果,南槽航道治理一期工程对近期江亚南沙的地形变化起到了重要影响,工程有效地控制了江亚南沙河势,遏制了局部冲刷发展的趋势,有利于稳定南槽航道的北侧边界。 展开更多
关键词 长江口 南槽 河势变化 南槽航道治理一期工程 江亚南沙
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Regulation of Water Masses to Hypoxia Zones in the Changjiang Estuary
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作者 YANG Xingxing FAN Haimei +6 位作者 ZHANG Hui CHEN Sisi YANG Ying JI Huanhong JIANG Xiaoshan DENG Bangping JIA Junhe 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第4期993-1002,共10页
The regulating ways of different water masses affecting the locations and intensities of hypoxia zones were studied based on the time-space continuum data from August 2011 to 2013–2017.The 6-year distribution of the ... The regulating ways of different water masses affecting the locations and intensities of hypoxia zones were studied based on the time-space continuum data from August 2011 to 2013–2017.The 6-year distribution of the hypoxic area in the Changjiang Estuary(CE)and its adjacent waters show that the hypoxic area can be divided into two segments.The southern segment is out of the south branch of the CE,whereas the northern segment is in the junction zone between the South Yellow Sea and the CE.The two segments were divided along the 31.5°–32°N latitude line.The northern and southern segments were dominated by the East China Sea shelf water(ECSSW)and Kuroshio subsurface water(KSW),respectively.When the KSW(salinity>34)intrusion reached the east of 123°E and south of 31°N,hypoxia zones mainly occurred in the southern segment covered by the Changjiang Diluted Water(CDW),meanwhile the Yellow Sea cold water mass may emerge in the northeastern area.When the KSW intensely invaded westward to the region between 122°and 122.5°E and northward to 31.5°N or further north,hypoxia zones appeared in the northern segment.The strength of the KSW with low dissolved oxygen concentration is the basic driving factor for the hypoxia occurrence in the CE.Moreover,the stratification is crucial for the southern segment,whereas the organic matter decomposition is dominated for the northern segment,even with severe hypoxia across the sea surface in the study area. 展开更多
关键词 changjiang Estuary(CE) HYPOXIA Kuroshio subsurface water(KSW) East China Sea shelf water(ECSSW) water masses
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长江流域青海区域水生生物完整性评价
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作者 王贺崐元 刘思嘉 +3 位作者 田菲 李柯懋 次成普措 赵凯 《人民长江》 北大核心 2024年第7期53-58,共6页
依据《长江流域水生生物完整性指数评价办法(试行)》的要求和指标,通过梳理历史记录和文献,厘清了长江流域青海区域水生生物完整性评价的基准值;于2022年开展全面系统地野外调查,并对研究区域的水生生物完整性进行了评价。结果显示:长... 依据《长江流域水生生物完整性指数评价办法(试行)》的要求和指标,通过梳理历史记录和文献,厘清了长江流域青海区域水生生物完整性评价的基准值;于2022年开展全面系统地野外调查,并对研究区域的水生生物完整性进行了评价。结果显示:长江流域青海区域鱼类种类基准值为20种,鱼类种类现状值为19种;长江在青海省境内的长江源河段、大渡河源河段,以及长江流域青海区域整体的水生生物完整性得分分别为88.22,82.67分和81.56分,完整性等级均为“良”。其中,长江源河段历史有记录以来的15种鱼类在此次调查中均被发现,反映长江源流域水生生物群落受人类干扰较少,重点保护物种完整。研究区域鱼类栖息地生境良好,但主要制约完整性的因素是水电站对河流的阻隔、外来物种入侵和关键物种川陕哲罗鲑的缺失。研究结果可为全面评估长江水生态完整性提供青海区域的基础数据,还可为科学评估长江十年禁捕成效、针对性开展水域生态修复提供科学依据。 展开更多
关键词 水生生物 生物多样性 生物完整性 珍稀濒危物种保护 水生态 青海省 长江流域
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粤北长江铀矿田隆升剥露历史和矿床保存——来自磷灰石裂变径迹热年代学的启示
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作者 陈柏林 高允 +2 位作者 王永 刘向冲 祁家明 《大地构造与成矿学》 EI CAS CSCD 北大核心 2024年第5期911-927,共17页
粤北长江铀矿田是中国南方最重要和最具代表性的花岗岩型铀矿田之一。前人关于长江铀矿田的研究工作主要涉及铀矿成因、成岩成矿时代和铀矿化机制等方面,关于控矿构造研究也集中在矿床形成过程方面(如导矿、运矿和储矿构造),对成矿后矿... 粤北长江铀矿田是中国南方最重要和最具代表性的花岗岩型铀矿田之一。前人关于长江铀矿田的研究工作主要涉及铀矿成因、成岩成矿时代和铀矿化机制等方面,关于控矿构造研究也集中在矿床形成过程方面(如导矿、运矿和储矿构造),对成矿后矿床的剥露历史和保存研究甚少。本文通过磷灰石裂变径迹测试,恢复了长江铀矿田热演化历史,结果显示晚白垩世末以来表现为单向隆升剥露降温过程,在约63~55 Ma和44~34 Ma存在两次快速隆升过程,约34~5 Ma冷却速率较慢,为构造平静期,5 Ma以来又发生了快速隆升。自75 Ma至今长江铀矿田的隆升剥蚀量为3 km左右。矿田内被NEE向棉花坑断裂和NWW向油洞断裂分割的书楼丘、棉花坑和长排三个矿区隆升剥蚀量差异非常微小,说明棉花坑断裂两侧和油洞断裂两侧在新生代时期没有明显的差异升降,也进一步佐证了棉花坑断裂和油洞断裂的活动性不大。结合控矿构造的发育特点、3.2~5.6 km的成矿深度以及相关的成矿温压条件,表明长江铀矿田深部资源保存良好,深部具有很大的找矿潜力。 展开更多
关键词 裂变径迹 低温热年代学 剥露 矿床保存 长江铀矿田 粤北
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基于GPR探测的长江源地区冰川与冻土厚度研究
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作者 周黎明 张杨 《长江科学院院报》 CSCD 北大核心 2024年第3期1-8,共8页
长江源地区的冰川变化揭示了青藏高原气候变化趋势。冰下地形探测作为冰川发育和运动过程研究的基础,对长江地区水土保持和淡水资源储量研究具有指导意义。长江科学院在长达10 a的江源科考基础上,分别于2022年、2023年采用探地雷达(GPR... 长江源地区的冰川变化揭示了青藏高原气候变化趋势。冰下地形探测作为冰川发育和运动过程研究的基础,对长江地区水土保持和淡水资源储量研究具有指导意义。长江科学院在长达10 a的江源科考基础上,分别于2022年、2023年采用探地雷达(GPR)技术对长江正源沱沱河发源地格拉丹东主峰的冰川厚度进行精准探测,并对查旦湿地冻土厚度上限进行了探测研究。结合多种冰川和冻土地质模型的GPR波场模拟结果,提高了GPR技术在长江源地区冰川和冻土探测的有效性和精准度。探测结果表明,格拉丹东主峰冰川厚度和查旦湿地冻土厚度上限均有不同程度降低,冰川厚度和冻土厚度上限观测是一个常年积累的结果,后续仍需持续进行观测,积累更多数据,分析变化趋势,以估算探测区域内冰储量,研究气候变化对冰川的影响效果。 展开更多
关键词 长江源 探地雷达(GPR) 冰川 冻土 气候变化 水土保持 淡水资源储量
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长江安徽段江湖连通性及生物通道恢复研究
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作者 刘宏高 熊昱 +3 位作者 李德旺 包琦琳 林国义 储涛 《人民长江》 北大核心 2024年第1期69-74,81,共7页
江湖阻隔是导致长江中下游江湖复合生态系统衰退的最主要原因,江湖连通和生物通道恢复是流域生态修复的重要措施之一。通过现场调查等方法研究了华阳河湖群、菜子湖、升金湖和安庆西江古道等与长江干流的阻隔现状及连通性特征,在此基础... 江湖阻隔是导致长江中下游江湖复合生态系统衰退的最主要原因,江湖连通和生物通道恢复是流域生态修复的重要措施之一。通过现场调查等方法研究了华阳河湖群、菜子湖、升金湖和安庆西江古道等与长江干流的阻隔现状及连通性特征,在此基础上探讨了技术和管理层面存在的问题并提出对策建议。结果发现:依托涉水工程建设开展恢复河湖生物通道的做法可以有效缓解江湖复合生态系统的衰退,尤其是以“过鱼设施建设、季节性灌江纳苗、生态水网建设”相结合的生物通道恢复方案具有技术可行性。相关成果可为长江中下游江湖连通性及生物通道恢复、国家水网建设提供有益的参考。 展开更多
关键词 江湖连通 生物通道 生态水网 灌江纳苗 过鱼设施 生态修复 长江中下游
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贵州黔西市长江煤矿可采煤层中微量元素地球化学特征及成煤环境分析
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作者 张博 杨维 《资源信息与工程》 2024年第1期59-62,共4页
煤中微量元素隐含着丰富的地质和成煤环境信息。研究煤中微量元素,对反演成煤环境、煤炭的高效清洁利用以及认识有害元素对人和生态环境的影响具有非常重要的意义。本文对贵州黔西市长江煤矿可采煤层中微量元素地球化学特征及成煤环境... 煤中微量元素隐含着丰富的地质和成煤环境信息。研究煤中微量元素,对反演成煤环境、煤炭的高效清洁利用以及认识有害元素对人和生态环境的影响具有非常重要的意义。本文对贵州黔西市长江煤矿可采煤层中微量元素地球化学特征及成煤环境进行了分析,结果表明:长江煤矿可采煤层形成于浅水富氧环境;可采煤层中Ga、Th、F相对富集;在煤层的开采利用过程中,应重视有害元素F的综合治理及生态环境保护。 展开更多
关键词 微量元素 有害元素 可采煤层 长江煤矿 成煤环境
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