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Impact of the Three Gorges Dam on reproduction of four major Chinese carps species in the middle reaches of the Changjiang River 被引量:20
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作者 黎明政 段中华 +2 位作者 高欣 曹文宣 刘焕章 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第5期885-893,共9页
Silver carp(Hypophthalmichthys molitrix),bighead carp(Aristichthys nobilis),grass carp(Ctenopharyngodon idella),and black carp(Mylopharyngodon piceus) are the four major Chinese carps and are commercially important aq... Silver carp(Hypophthalmichthys molitrix),bighead carp(Aristichthys nobilis),grass carp(Ctenopharyngodon idella),and black carp(Mylopharyngodon piceus) are the four major Chinese carps and are commercially important aquaculture species in China.Reproduction of these carp has declined since the construction of the Three Gorges Dam(TGD) due to an altered water flow and thermal regime in the Changjiang(Yangtze) River.However,details of the changes in reproduction of the four species are not well understood.To assess the impact of the TGD on reproduction of the four carp,we investigated their eggs and larvae at Yidu City,which is 80 km below the TGD,during 2005-2012.We examined differences in larval abundance of the four species in the Jianli section(350 km downstream of the TGD) before(1997-2002)and after(2003-2012) construction of the TGD.Based on these observations,the first spawning date of the four species was delayed a mean of about 25 days after the dam was constructed.Mean egg abundance in the Yidu section of the river was 249 million and mean larval abundance was 464 million,which were significant decreases since the 1980 s.Moreover,larval abundance in the Jianli section after the dam was constructed was significantly lower than that before construction(ANCOVA,P<0.05).The observed larval abundance accounted for only 24.66%of the predicted value in 2003 when the dam was first inundated.The present spawning grounds between the TGD and Yidu section of the river are very similar to those described in the 1980 s,and some spawning grounds exist upstream of the TGD.Large free-flowing stretches upstream of the TGD and the creation of artificially flooded downstream reaches are needed to stimulate spawning and effectively conserve these four major Chinese carps species. 展开更多
关键词 changjiang(yangtze) river Three Gorges Dam Chinese carp REPRODUCTION eggs and larvae
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长江溶存氧化亚氮的分布与释放 被引量:21
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作者 赵静 张桂玲 +1 位作者 吴莹 张经 《环境科学学报》 CAS CSCD 北大核心 2009年第9期1995-2002,共8页
于2008年1月对长江宜昌到徐六泾段干流以及部分湖泊和支流入江口进行了调查,并于2007年6月到2008年5月对长江徐六泾进行了逐月调查,采样测定了长江溶存N2O的浓度并选择合适的模型估算了其释放通量.结果表明,2008年1月长江表层河水中N2O... 于2008年1月对长江宜昌到徐六泾段干流以及部分湖泊和支流入江口进行了调查,并于2007年6月到2008年5月对长江徐六泾进行了逐月调查,采样测定了长江溶存N2O的浓度并选择合适的模型估算了其释放通量.结果表明,2008年1月长江表层河水中N2O的平均浓度为(22.0±3.5)nmo·lL-1,均处于过饱和状态,平均饱和度为180%±33%,长江向大气释放N2O通量平均为(13.7±14.6)μmol·m-·2d-1.冬季长江溶存N2O的分布规律为下游溶存N2O浓度高于中游,支流及湖泊高于干流.长江徐六泾段河水中N2O全年平均浓度为(19.4±7.3)nmol·L-1,呈现明显季节变化特征.长江徐六泾段河水中N2O平均释放通量为(43.9±24.9)μmol·m-2·d-1,夏季最高可达80.7μmol·m-·2d-1.初步估算出长江每年向大气释放N2O-N的量为12.0Gg·a-1,约占整个中国N2O排放量的1.1%.而长江输入东、黄海N2O-N的年通量为0.5Gg·a-1,对长江口及其邻近海域N2O分布及氮的生物地球化学循环有重要影响. 展开更多
关键词 长江 氧化亚氮(N20) 释放 分布 通量
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黄河与长江入海沉积物中碳酸盐含量和矿物颗粒形态特征及影响因素 被引量:16
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作者 杨作升 王海成 乔淑卿 《海洋与湖沼》 CAS CSCD 北大核心 2009年第6期674-681,共8页
利用X射线物相分析、扫描电镜及能谱分析等方法分析了长江和黄河入海沉积物矿物颗粒形态特征及不同粒级的碳酸盐矿物百分含量分布。结果表明,长江和黄河入海沉积物的碳酸盐矿物含量均在9%左右,差异不大。长江碳酸盐矿物含量在粗粒级较高... 利用X射线物相分析、扫描电镜及能谱分析等方法分析了长江和黄河入海沉积物矿物颗粒形态特征及不同粒级的碳酸盐矿物百分含量分布。结果表明,长江和黄河入海沉积物的碳酸盐矿物含量均在9%左右,差异不大。长江碳酸盐矿物含量在粗粒级较高,随着粒度变细波动式降低,黄河碳酸盐矿物含量则随粒度变细而逐步增加;黄河方解石含量高而白云石低,长江的情况正好相反。长江和黄河入海沉积物中的白云石颗粒大多比较完整,侵蚀沿完全解理面发生,菱面体形态明显。长江白云石上可以见到大量的磨蚀和溶蚀形态。黄河白云石保存较好,侵蚀程度较低,磨蚀和碰撞形态明显,溶蚀形态很少,发现典型的马鞍状白云石颗粒。长江和黄河的方解石均遭受强烈侵蚀。长江方解石溶蚀特征特别明显,深入矿物颗粒内部。黄河方解石侵蚀深度相对浅表,侵蚀形态多为磨蚀、碰撞和溶蚀等物理和化学综合侵蚀特征。长江某些方解石表面布满细小鲕状方解石颗粒,似为局部自由空间的胶体-陈化成因特征。黄河方解石呈现多个次生微晶集合体,显示其黄土粘粒空隙胶结物成因形态。碳酸盐矿物的菱面体形态和菱面体完全解理所特有的60°和120°交角,是其电镜下的最佳识别特征。长江和黄河沉积物物源、流域风化强度以及矿物晶体结构本身的特点,是两河沉积物中碳酸盐矿物含量及颗粒形态差异的主要影响因素。 展开更多
关键词 长江与黄河 沉积物 碳酸盐矿物 形态特征 风化
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长江中溶存甲烷的分布与释放 被引量:14
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作者 赵静 张桂玲 +1 位作者 吴莹 杨晶 《环境科学》 EI CAS CSCD 北大核心 2011年第1期18-25,共8页
2008年1月和9月对长江的中、下游和长江口进行了调查,2007年9月~2008年8月每月在长江徐六泾进行了调查,用吹扫捕集-气相色谱法测定了长江各站位水体中甲烷的浓度并用Wanninkhof公式估算向大气的甲烷释放通量.结果表明,2008年1月长江中... 2008年1月和9月对长江的中、下游和长江口进行了调查,2007年9月~2008年8月每月在长江徐六泾进行了调查,用吹扫捕集-气相色谱法测定了长江各站位水体中甲烷的浓度并用Wanninkhof公式估算向大气的甲烷释放通量.结果表明,2008年1月长江中、下游表层水中甲烷平均浓度为(330.8±186.9)nmol.L-1,2008年9月长江下游和河口表层水中甲烷平均浓度为(80.9±58.3)nmol.L-1,各站位底层水体中甲烷浓度与表层基本一致.长江中溶存甲烷均处于过饱和状态,是大气中甲烷的净源.长江向大气释放甲烷的平均通量为(385.1±278.0)μmol.(m2.d)-1.长江徐六泾表层水中甲烷的年平均浓度为(167.5±91.4)nmol.L-1,高值出现在2月和7月,向大气释放甲烷的年平均通量为(690.9±291.6)μmol.(m2.d)-1.长江中溶存甲烷浓度的空间分布呈现自中游向下沿江逐渐增大的趋势,最高值出现在鄱阳湖下游的孤山站,然后向下游呈递减趋势.支流及湖泊富甲烷水的输入对长江干流甲烷的浓度分布有明显的影响.长江口自徐六泾向外海方向,表层水中甲烷浓度迅速减小.本研究初步估算出长江每年向大气释放甲烷量为208 Gg.a-1,向东、黄海输入甲烷的量为112×106mol.a-1. 展开更多
关键词 长江 甲烷(CH4) 释放 分布 通量
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长江三角洲东缘晚新近纪沉积的孢粉与古环境研究 被引量:11
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作者 贾丽 张玉兰 《微体古生物学报》 CSCD 北大核心 2006年第1期70-76,共7页
作者对长江三角洲东缘地区的南汇鹤鸣孔(Hm)、东海1井、高桥G2孔3口钻井晚新近纪地层的孢粉作了研究和对比,划分出了6个孢粉组合带和3个亚带,恢复了本地区植被演替、气候波动的6个阶段:第1阶段为稀疏的针叶、落叶阔叶混交林,反映气候凉... 作者对长江三角洲东缘地区的南汇鹤鸣孔(Hm)、东海1井、高桥G2孔3口钻井晚新近纪地层的孢粉作了研究和对比,划分出了6个孢粉组合带和3个亚带,恢复了本地区植被演替、气候波动的6个阶段:第1阶段为稀疏的针叶、落叶阔叶混交林,反映气候凉冷稍湿;第2阶段为针叶阔叶混交林草地,反映气候温凉略湿;第3阶段为含常绿阔叶树的针叶阔叶混交林,反映气候温和略干;第4阶段为以常绿栎类、栲属、杨梅等为主的常绿阔叶林,反映气候热暖潮湿;第5阶段是以栎、松、禾本科为主的针叶、阔叶混交林,反映气候温暖略干;第6阶段是以落叶栎类、常绿栎类、松为主的落叶阔叶、常绿阔叶、针叶混交林草地,反映气候温暖湿润。这种气候波动与世界性气候变化相一致,为本地区的地层年代划分和对比提供了新的证据,为晚新近纪古植被、古气候、古环境的重建提供了重要的孢粉学资料。 展开更多
关键词 孢粉组合 古环境 晚新近纪 长江三角洲东缘地区
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Heavy metals in Changjiang estuarine and offshore sediments:responding to human activities 被引量:8
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作者 DONG Aiguo ZHAI Shikui +3 位作者 Matthias Zabel YU Zenghui ZHANG Huaijing LIU Feifei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第2期88-101,共14页
The Changjiang (Yangtze) estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions. Distributions of heavy metals show typical banded diffusion pattern, with high co... The Changjiang (Yangtze) estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions. Distributions of heavy metals show typical banded diffusion pattern, with high concentrations near the river mouth and following a decreasing trend in the offshore direction. According to chemical fractions, Fe/Mn oxide fraction is the major non-residual fraction in the Changjiang estuarine and offshore sediments, Higher percentage of non-residual fraction of Pb implies that, the industrial contaminations transported via the atmosphere and river input, may affect the non-residual fraction of heavy metals. Over past fifteen years, the concentration of Pb normalizing to A1 presents significant increasing trend, corresponding to the effect of human activities. By comparison of heavy metals fractions in 2003 to 2006, it has been realized that increasing water and sediment may cause a higher percentage non-residual fraction of Cu in the southern part of offshore muddy sediments. 展开更多
关键词 sediment heavy metal FRACTION changjiang yangtze river
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Changjiang River sediment delivering into the sea in response to water storage of Sanxia Reservoir in 2003 被引量:6
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作者 CHU Zhongxin ZHAI Shikui CHEN Xiufa 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第2期71-79,共9页
The Sanxia Reservoir on the Changjiang River stored water from 1 to 10 June and from 25 October to 5 November in 2003, elevating the water level to 135 and 139 m above mean sea level at the dam, respectively. A monthl... The Sanxia Reservoir on the Changjiang River stored water from 1 to 10 June and from 25 October to 5 November in 2003, elevating the water level to 135 and 139 m above mean sea level at the dam, respectively. A monthly dataset of water discharge, suspended sediment concentration (SSC) and sediment load of the Changjiang River from 1953 to 2003 measured at the Datong Hydrological Gauging Station of the downstreammost Changjiang River was mainly used to examine the Changjiang River sediment delivering into the sea in 2003 in response to the Sanxia Reservoir water storages in the same year. The results show that (1) compared with those in 2002, 2001, and the multi-yearly (1953-2000) average, both annual SSC and sediment load at Datong in 2003 were markedly reduced, and they were even smaller than the multi-yearly (1953-2000) minimum, although the annual runoff in 2003 did not change largely; and (2) compared with those in the corresponding months in 2002, 2001 and the multi-monthly average from 1953 to 2000, monthly SSC and sediment load at Datong both in June and November of 2003 were also markedly reduced, and those in June 2003 were even smaller than the multi-monthly minimum from 1953 to 2000. These may indicate that sediment sedimentation in the Sanxia Reservoir resulting from the Sanxia Reservoir water storage should be the main cause of the decreased annual and monthly SSC and sediment load of the Changjiang River into the sea in 2003. Besides, it seems that the Sanxia Reservoir water storage in the early June (flood season) of 2003 had more impacts on the decreased monthly SSC into the sea than that in the late October and early November (approximately non-flood season) of 2003. 展开更多
关键词 changjiang yangtze river Sanxia Reservoir water storage SEDIMENT
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基于文献计量的长江洪水研究态势分析 被引量:5
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作者 万洪秀 吴昊 郭娅 《长江科学院院报》 CSCD 北大核心 2019年第7期153-158,共6页
为揭示长江洪水研究的现状与发展趋势,运用文献计量学等方法,基于SCIE与CSCD文献数据库对长江洪水研究的发文年代、国际合作、研究机构、核心作者、期刊分布、热点关键词等方面进行了系统性的分析。结果表明:①SCIE与CSCD发文量在1998... 为揭示长江洪水研究的现状与发展趋势,运用文献计量学等方法,基于SCIE与CSCD文献数据库对长江洪水研究的发文年代、国际合作、研究机构、核心作者、期刊分布、热点关键词等方面进行了系统性的分析。结果表明:①SCIE与CSCD发文量在1998年后迅速增长,尤其是SCIE文献增长显著,中国与美国、德国等发达国家合作发文较多;②中国科学院的英文和中文文献数量均居于领先水平,约占SCIE与CSCD总文献的31%和23%,中、外文核心作者分别约占作者总数的21%和27%, SCIE文献发表在《Journal of Hydrology》期刊最多,各约占总文献的4%,CSCD文献发表在《长江流域资源与环境》和《长江科学院院报》的最多,各占全部文献的7.28%;③长江洪水研究热点关键词频次>20的主要是三峡、降水、气候变化、沉积、洪涝灾害等,这些热点关键词反映了长江洪水发生机制及灾害缓解研究的发展态势。研究成果可以为未来长江洪水相关研究提供参考。 展开更多
关键词 长江 洪水研究 SCIE CSCD 文献计量 定量分析 研究态势
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Assessment of trophic status in Changjiang (Yangtze) River estuary 被引量:3
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作者 WANG Baodong 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2007年第3期261-269,共9页
The integrated methodology for the assessment of estuarine trophic status(ASSETS),which was extended and refined from the United States National Estuarine Eutrophication Assessment(NEEA),is a multi-parameter assessmen... The integrated methodology for the assessment of estuarine trophic status(ASSETS),which was extended and refined from the United States National Estuarine Eutrophication Assessment(NEEA),is a multi-parameter assessment system and has been widely used in eutrophication assessment in estuarine and coastal waters.The ASSETS was applied to evaluate the trophic status of the Changjiang(Yangtze)River estuary,one of the largest estuaries in the world.The following main results were obtained:(i)The estuarine export potential is"moderate susceptibility"due to the"moderate"dilution potential and"moderate"flushing potential;(ii)The overall human influence(OHI)index classified the impact of nutrients in the system as"high"due to the high level of nutrient discharge by the river which channels anthropogenic impacts in the catchments to the estuarine system;(iii)The overall eutrophic condition(OEC)in the estuary was classified into the"high"category due to frequent occurrence of nuisance and toxic algal blooms in the mixing and seawater zones;(iv)Since the nutrient loadings(e.g.,DIN)in the river is expected to continue to increase in the near future following the population increase and rapid economic growth throughout the drainage basin,the nutrient-related symptoms in the estuary are likely to substantially worsen,which leads to the"worsen high"category for the definition of future outlook(DFO).The combinations of the three components(i.e.,OHI,OEC,and DFO)lead to an overall grade as"bad"for the trophic status in the Changjiang River estuary. 展开更多
关键词 EUTROPHICATION model ESTUARY changjiang(yangtze)river ASSETS index
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不同判别方法在长江水流挟沙力公式检验中的应用 被引量:3
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作者 高幼华 范北林 +1 位作者 侯卫国 胡石华 《长江科学院院报》 CSCD 北大核心 2009年第2期14-17,共4页
水流挟沙力是运用河流动力学原理进行河床冲淤计算的重要指标,对常见的水流挟沙力公式进行了检验,检验所采取的判别方法有:相关系数法、最小距离法、集中系数法、偏离系数法和聚类分析方法。结果表明:相关系数法、最小距离法、集中系数... 水流挟沙力是运用河流动力学原理进行河床冲淤计算的重要指标,对常见的水流挟沙力公式进行了检验,检验所采取的判别方法有:相关系数法、最小距离法、集中系数法、偏离系数法和聚类分析方法。结果表明:相关系数法、最小距离法、集中系数法、偏离系数法的检验结果在整体趋势上是一致的,但检验结果相互间存在一定的偏差;而聚类分析是根据聚类标准将不同的公式划分为不同类别,视同一类的计算效果相当,能将其他几种方法的结果较好地统一起来。 展开更多
关键词 水流挟沙力 长江 公式检验 聚类分析
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2015—2016年长江口及其邻近海域甲藻群落与阿米巴藻感染的周年变化 被引量:3
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作者 陈田田 宋书群 +1 位作者 刘云 李才文 《海洋与湖沼》 CAS CSCD 北大核心 2019年第1期139-148,共10页
通过2015年2月—2016年1月间在长江口及其邻近海域开展的10个航次调查,研究了该海域浮游甲藻的群落特征和时空变化,分析了寄生性甲藻阿米巴藻宿主种类及其感染率的周年变化。研究结果表明:调查海域浮游甲藻群落结构相对稳定,共检出浮游... 通过2015年2月—2016年1月间在长江口及其邻近海域开展的10个航次调查,研究了该海域浮游甲藻的群落特征和时空变化,分析了寄生性甲藻阿米巴藻宿主种类及其感染率的周年变化。研究结果表明:调查海域浮游甲藻群落结构相对稳定,共检出浮游甲藻类38种,膝沟藻目处于绝对优势,优势种全年既有交叉又有演替;各季节间浮游甲藻丰度差异不显著(P>0.05),但各月间浮游甲藻丰度差异显著(P<0.05);全年丰度在9.06×10~3—6.10×10~6cells/L之间,其中4月份甲藻丰度最高,2月的丰度最低,全年的平均丰度为6.62×10~5cells/L。调查海域阿米巴藻宿主甲藻种类繁多,14种浮游甲藻被寄生感染,感染率范围为0.006%—5.13%;该海域阿米巴藻宿主种类及感染率表现出明显的季节差异,夏、秋两季宿主种类较多,感染率也明显高于春、冬两季。 展开更多
关键词 长江口 浮游甲藻 群落结构 阿米巴藻 周年变化
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SIMULATION MODELLING OF THE IMPACTS OF SEA-LEVEL RISE SINCE THE LATEGLA-CIAL PERIOD ON THE CHANGJIANG(YANGTZE) RIVER, CHINA 被引量:1
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作者 方金琪 《Science China Chemistry》 SCIE EI CAS 1991年第10期1258-1269,共12页
Dramatic water stage rise and channel aggradation in the middle and lower reaches of the Changjiang (Yangtze) River have been recognized by previous studies. A further analysis of the data from geological, geomorpholo... Dramatic water stage rise and channel aggradation in the middle and lower reaches of the Changjiang (Yangtze) River have been recognized by previous studies. A further analysis of the data from geological, geomorphological, and paleohydrological surveys suggests that these changes might have resulted from sea-level rise since the Lateglacial period. So a mathematical model has been developed here, which reconstructs the processes of water-stage rise and channel aggradation of the Changjiang River as responses to sea-level rise since 12,100 a B.P. 展开更多
关键词 SEA-LEVEL rise changjiang (yangtze) river Lateglaeial period.
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Simulating the responses of a low-trophic ecosystem in the East China Sea to decadal changes in nutrient load from the Changjiang(Yangtze) River
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作者 王玉成 郭新宇 赵亮 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第1期48-61,共14页
Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the perio... Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the period of 1960–2005.Two major factors aff ected changes in nutrient load:changes in river discharge and the concentration of nutrients in the river water.Increasing or decreasing Changjiang discharge induced different responses in the concentrations of nutrients,phytoplankton,and detritus in the ECS.Changes in dissolved inorganic nitrogen(DIN),silicate(SIL),phytoplankton,and detritus could be identified over a large area of the ECS shelf,but changes in dissolved inorganic phosphate(DIP)were limited to a small area close to the river mouth.The high DIN:DIP and SIL:DIP ratios in the river water were likely associated with the diff erent responses in DIN,DIP,and SIL.As DIP is a candidate limiting nutrient,perturbations in DIP resulting from changes in the Changjiang discharge are quickly consumed through primary production.It is interesting that an increase in the Changjiang discharge did not always lead to an increase in phytoplankton levels in the ECS.Phytoplankton decreases could be found in some areas close to the river mouth.A likely cause of the reduction in phytoplankton was a change in the hydrodynamic field associated with the river plume,although the present model is not suitable for examining the possibility in detail.Increases in DIN and DIP concentrations in the river water primarily led to increases in DIN,DIP,phytoplankton,and detritus levels in the ECS,whereas decreases in the SIL concentration in river water led to lower SIL concentrations in the ECS,indicating that SIL is not a limiting nutrient for photosynthesis,based on our model results from 1960 to 2005.In both of the above-mentioned cases,the sediment accumulation rate of detritus exhibited a large spatial variation near the river mouth,suggesting that core sample data should be carefully interpreted. 展开更多
关键词 East China Sea changjiang(yangtze) river low-trophic ecosystem
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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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Larva fish assemblage structure in three-dimensional floating wetlands and non-floating wetlands in the Changjiang River estuary 被引量:1
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作者 Xiaofeng HUANG Feng ZHAO +3 位作者 Chao SONG Yi CHAI Qian WANG Ping ZHUANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第2期721-731,共11页
Fish populations have declined in many estuarine and freshwater ecosystems in part due to the loss of habitat in recent decades.Reconstructing lost habitat for larvae fish is a potential method for recovering larvae f... Fish populations have declined in many estuarine and freshwater ecosystems in part due to the loss of habitat in recent decades.Reconstructing lost habitat for larvae fish is a potential method for recovering larvae fish populations.Three-dimensional artificial floating wetlands(AFWs)on which Phragmites australis was planted were experimentally deployed to recover the lost habitat in the Changjiang(Yangtze)River estuary from May to July 2018.The AFW area was characterized by slow velocity,high transparency,low dissolved oxygen,and relatively constant water temperature.The total individuals of larvae fish in the AFW area(12122 in total)was higher than that in the non-AFW area(1250 in total),and the densities of most larvae fish species were higher in the AFW habitat than in the non-AFW area.The distributions of larvae fish species were positively influenced by habitat type because they were strongly related to the negative part of the first axis of the redundancy analysis,and Cyprinus carpio and Cyprinus auratus were inclined to habitat in the slow velocity and high transparency AFW habitat area.These results indicate that larvae fish species are inclined to inhabit the AFW habitat.The use of three-dimensional P.australis AFWs would be a potential method for enhancing the habitat of larvae fish in the degraded habitats along the estuary. 展开更多
关键词 habitat rehabilitation larvae fish biodiversity conservation artificial floating wetland changjiang(yangtze)river estuary
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中国长江上的桥梁建设
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作者 邹立中 周璞 《铁道工程学报》 EI 1997年第1期93-96,共4页
本文根据前苏联运输工程部一位局长н.м.柯洛柯洛夫的遗作编译而成,主要介绍苏联专家在解放初期援助我国铁路工程建设和长江上修建桥梁的一些情况。
关键词 长江大桥 建桥
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长江口河口锋区浮游动物生态研究Ⅰ生物量及优势种的平面分布 被引量:124
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作者 陈亚瞿 徐兆礼 +3 位作者 王云龙 胡方西 胡辉 谷国传 《中国水产科学》 CSCD 1995年第1期49-58,共10页
据1988年及1989年于长江口羽状流锋区调查及东海水产研究所多年调查资料综合分析研究结果表明,浮游动物生物量在丰水期(1988年8月)的平均生物量为438毫克/米 ̄3,变异系数为0.78;1989年8月平均生物量为... 据1988年及1989年于长江口羽状流锋区调查及东海水产研究所多年调查资料综合分析研究结果表明,浮游动物生物量在丰水期(1988年8月)的平均生物量为438毫克/米 ̄3,变异系数为0.78;1989年8月平均生物量为350毫克/米 ̄3。生物量分布呈现自西北向东南部水域递增的趋向。高生物量主要分布于122°20′─122°50E,30°50′─31°20′N范围内,平均生物量高达962毫克/米 ̄3,变异系数为0.32。生物量分布趋势与常年相同。而枯水期(1988年12月)的平均生物量低,仅为68.38毫克/米 ̄3,变异系数为1.5,高生物量区较小分布不均匀。优势种中华哲水蚤Calanussinicus、乌啄尖头Peniliaavirostris、肥胖三角Evadnetergeslina、真刺唇角水蚤Labidoceraeuchaeta、背针胸刺水蚤Centropagesdosispinatus、太平洋纺锤水蚤Acartiapacifica、虫肢歪水蚤Tortanusvermiculus、肥胖箭虫Sagittaenfla─ta、海龙箭虫Sagittanagae等多种浮游动物为长江口外的优势种,并对其数量分布进? 展开更多
关键词 长江口 河口锋区 浮游动物 生物量 优势种
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长江三角洲城市群发展展望 被引量:62
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作者 顾朝林 张敏 +3 位作者 张成 张晓明 汪淳 陈璐 《地理科学》 CSCD 北大核心 2007年第1期1-8,共8页
长江三角洲城市群是中国最大的城市群,其发展和演变对中国城市发展、中国沿海经济乃至亚太地区的发展均具有举足轻重的地位和作用。改革开放以来,中国经济的迅速增长,经济全球化过程的加速,均为长江三角洲城市群的发展提供难得的机遇与... 长江三角洲城市群是中国最大的城市群,其发展和演变对中国城市发展、中国沿海经济乃至亚太地区的发展均具有举足轻重的地位和作用。改革开放以来,中国经济的迅速增长,经济全球化过程的加速,均为长江三角洲城市群的发展提供难得的机遇与挑战。重点论述长江三角洲城市群发展展望。 展开更多
关键词 长江三角洲 城镇群
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长江口及邻近海域小型底栖生物丰度和生物量 被引量:54
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作者 华尔 张志南 张艳 《生态学报》 CAS CSCD 北大核心 2005年第9期2234-2242,共9页
“东方红2号”调查船于2003年6月在长江口外(28°N°至32°N,121°E至123°E)陆架浅海水域进行了小型底栖生物的取样。研究表明,小型底栖生物的平均丰度为(1971±583.9)ind10cm-2,平均生物量为(1393±516.1... “东方红2号”调查船于2003年6月在长江口外(28°N°至32°N,121°E至123°E)陆架浅海水域进行了小型底栖生物的取样。研究表明,小型底栖生物的平均丰度为(1971±583.9)ind10cm-2,平均生物量为(1393±516.1)μgdwt10cm-2,平均生产量为(12543±4644.7)μgdwt10cm-2a-1。共鉴定出21个小型生物类群,其中自由生活海洋线虫为最优势的类群,占小型生物总丰度的91%和总生物量的51%。其他数量上较重要的类群还有底栖桡足类、多毛类、动吻类和双壳类等。相关分析表明,小型底栖生物的数量分布与沉积物叶绿素和脱镁叶绿酸的含量呈高度显著相关。台风前后8号站线虫群落的比较研究表明,台风后线虫群落在丰度,生物量及种类组成上均发生了一定的变化,对台风的响应较为显著。典型站位自由生活海洋线虫种类组成的分析表明,长江入海口向外线虫优势度降低,多样性增加。 展开更多
关键词 小型底栖生物 自由生活海洋线虫 丰度 生物量 长江口
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东海赤潮高发区春季溶解氧和pH分布特征及影响因素探讨 被引量:50
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作者 石晓勇 王修林 +1 位作者 陆茸 孙霞 《海洋与湖沼》 CAS CSCD 北大核心 2005年第5期404-412,共9页
根据2002年4月27日—5月2日长江口邻近海域的大面调查,分析了东海溶解氧及pH值的分布特征,并对长江口外溶解氧低值区的成因及其与赤潮发生的关系进行了初步探讨。结果表明,调查海域pH值呈近岸低、外海高的分布趋势,溶解氧整体处于过饱... 根据2002年4月27日—5月2日长江口邻近海域的大面调查,分析了东海溶解氧及pH值的分布特征,并对长江口外溶解氧低值区的成因及其与赤潮发生的关系进行了初步探讨。结果表明,调查海域pH值呈近岸低、外海高的分布趋势,溶解氧整体处于过饱和状态,呈近岸高、外海低的分布趋势。4月下旬在调查海区东南部底层已开始出现溶解氧低值区,面积约为15400km2,该水域表观耗氧量AOU一般在1.50mg/L以上,并伴随有氧的亏损发生,形成原因主要是水交换较弱和有机物分解耗氧。溶解氧低值区可能是有机碎屑的沉降汇集区,随着夏季温度的升高及长江丰水期的到来,有机碎屑有可能在台湾暖流的影响下产生西、北向的爬升而造成溶解氧低值区扩大和溶解氧含量的进一步降低。 展开更多
关键词 溶解氧 溶解氧低值区 东海 长江口
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