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Physical Modeling of Localized Scour for the yangtze estuary Waterway Improvement Project,Phase Ⅰ

China Ocean Engineering 2000年第4期15卷 473-484页

作者：贾建军卢无疆钱亚东 Ph. D. Candidate，School of Harbor，Waterway and Coast Engineering，Hohai University，Nanjing 210098 Institute of Oceanology，Chinese Academy of Sciences，Qingdao 266071，P. R. China Professor，School of Harbor，Waterway and Coast Engineering，Hohai University，Nanjing 210098，P. R. China Lecturer，School of Geographic Sciences，Nanjing Normal University，Nanjing 210097，P. R. China

In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the yangtze estuary Waterway Improvement Project, Phase I , an undistort-ed physical model on a geometric scale of 1:250 is built in this study, covering two groins and their adacent estuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model, the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredging leads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Construction of the upstream groin has some influence on the flow patterns near the downstream groin. Localized scour in front of the groin-heads is controlled mainly by ebb flow. In the case of a riverbed composed entirely of silt, the depths of localized scour in front of the two groin- heads are 27 m and 29 m, respectively. In reality, the underneath sediment of the prototype riverbed is clay whose threshold velocity is much higher than the stream velocity in the yangtze estuary; therefore, the depths of localized scour will not be much larger than the thickness of the silt layer, i. e. 7.4 m and 4.7 m, respectively. The designed aprons covering the riverbed in fron of the groin-heads are very effective in scour control. Aprons of slightly smaller size can also fulfill the task of protection, but the area of localized scour increases significantly.

关键词： yangtze estuary physical modelling localized scour waterway dredging groin

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Three Dimensional Baroclinic Numerical Model for Simulating Fresh and Salt Water Mixing in the yangtze estuary

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China Ocean Engineering 2002年第2期17卷 227-238页

作者：郑金海严以新诸裕良 Research Institute of Coastal and Ocean Engineering Hohai University

For simulating fresh and salt water mixing in estuaries, a three dimensional nonlinear baroclinic numerical model is developed, in which the gradients of horizontal pressure contain die gradient of barotropic pressure arising from the gradient of tidal level and the gradient of baroclinic pressure due to the gradient of salinity. The Eulerian-Lagrangian method is employed to descretize both the momentum equations of tidal motion and the equation of salt water diffusion so as to improve the computational stability and accuracy. The methods to provide the boundary conditions and the initial conditions are proposed, and the criterion for computational stability of the salinity fields is presented. The present model is used for modeling fresh and salt water mixing in the yangtze estuary. Computations show that the salinity distribution has the characteristics of partial mixing pattern, and that the present model is suitable for simulation of fresh and salt water mixing in the yangtze estuary.

关键词： fresh and salt water mixing numerical model baroclinic pressure Eulerian-Lagrangian method yangtze estuary

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Morphological Evolution and Its Response to the Navigational Improvements in the North Passage,yangtze estuary

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China Ocean Engineering 2007年第4期21卷 611-624页

作者：刘杰陈吉余徐志扬乐嘉海 State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai Estuarine and Coastal Science Research Center

By use of bathymetric chart, recent change of the riverbed in the North Passage of the yangtze estuary has been studied in this paper. The main channel of the upper, middle and lower （section） in the North Passage has been successively eroded and its groin field significantly deposited. At the same time, sediment has been deposited on the entrance region. Erosion and deposition had responded rapidly to the construction of the regulation engineering. There was about one year duration of lagging between erosion in the deep channel and the construction of the regulation engineering. The siltation lag of time in the groin field varied with the initial depth, but the average deposited thickness was about 0.5 m per year. Volumetric analysis demonstrates that there is a increasing trend of siltation in the North Passage after 2002, because of the difference in duration and quantity between erosion in the deep channel and deposition in the groin field. The water volume of the North Passage was reduced by =9% （280 million m^3） between 2002 and 2006. Sediment budget reveals that the main sediment deposited in the North Passage takes its source from the river and the ocean. The decreasing water volume was attributable to shoaling in the groin field. Its triggering factors for increased sedimentation are the navigational improvements（jetties and groins） after 1998, which altered the passage boundary and destroyed the equilibrium state on the average ebb and flood sediment fluxes. The establishment of a stable estuary is attributed to a reduction in depth of the groin field. The forecast on the sediment deposition quantity and continuous infilling time in the groin system is about 325 × 10^6m^3 and 6 - 7 years, respectively.

关键词： yangtze estuary North Passage navigational improvements bathymetric data

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Characteristics and Origins of Suspended Pyrite in the Mixing Zone of the yangtze estuary

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Journal of Ocean University of China 2020年第4期19卷 801-810页

作者： PANG Yue FAN Dejiang SUN Xiaoxia SUN Xueshi LIU Ming YANG Zuosheng Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of EducationOcean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology(QNLM)Qingdao 266061China Center for Isotope Geochemistry and Geochronology Qingdao National Laboratory for Marine Science and Technology(QNLM)Qingdao 266061China

For a long time,most studies about pyrite have focused on sediments while only a few have focused on pyrite in *** this study,a method that combines the scanning electron microscopy(SEM)and the energy dispersive X-ray spectrometry(EDS)was used to compare pyrite particles suspended in water to those in associated bottom sediments,both obtained from the mixing zone of the yangtze *** was found that the pyrite particles in the two media have similar morphologies and size *** particle morphology mainly includes two types,single crystal and aggregate,and the particle size mainly ranges from 0.5 to 2μ*** pyrite particles in water exhibit an increase in relative content towards the sea,and their transport and deposit processes are mainly affected by hydrodynamic *** is concluded that the pyrite particles in the suspended matter mainly derived from the resuspension of sediments,which are products of the early *** minerals may appear during the formation of pyrite,but are generally restricted by the diagenetic environment and local microenvironment.

关键词： yangtze estuary suspended matter pyrite resuspension authigenic mineral

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Hydrodynamic and morphological processes in yangtze estuary:State-of-the-art research and its applications by Hohai University

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Water Science and Engineering 2012年第4期5卷 383-398页

作者： Jin-hai ZHENG Yi-xin YAN Chao-feng TONG Zhi-yi LEI Chi ZHANG State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Harbor Coastal and Offshore EngineeringHohai University

This paper presents a review of the state-of-the-art research and its applications developed at Hohai University relating to the hydrodynamic and morphological processes in the yangtze estuary. Longitudinal, lateral, and horizontal flow circulations have been revealed based on the measurements with acoustic Doppler current profilers （ADCP）. The hydrodynamic mechanism at diversion points as well as the changing patterns of flow and sediment flux in the yangtze estuary has been investigated through long-term data analysis. A field survey has been carried out to detect the saltwater intrusion from the North Branch to South Branch. Different numerical models of flow motion, sediment transport, and saltwater intrusion have been developed to simulate the complicated processes and to evaluate the effects of engineering projects. The morphological processes of wetlands over a time scale of decades have been analyzed with an established database. Ideas for further research on the bio-geomorphological model system and long-term evolution mechanisms are put forward.

关键词： yangtze estuary hydrodynamic process morphological process saltwater intrusion,Hohai University

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In-Situ Observation of Fluid Mud in the North Passage of yangtze estuary, China

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海洋工程：英文版 2004年第1期18卷 149-156页

作者：李九发万新宁何青应铭时连强 S.M. Hutchinso State Key Laboratory for Estuarine and Coastal Research Telford Institute of Environmental Systems

Observations of fluid mud were made in the lower North Passage of the yangtze estuary in February 2000, on 10～11 August 2000, on 30～31 August 2000 (after two strong typhoons), on 21～24 August 2000 (neap tide) and on 3～6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.

关键词： fluid mud in situ observations north passage yangtze estuary China

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Diel vertical migration of dominant planktonic crustaceans in the south branch of yangtze estuary,China

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Aquaculture and Fisheries 2021年第4期6卷 414-423页

作者： Tianli Li Tonglin Liu Ruhan Liu Lijing Chen National Demonstration Center for Experimental Fisheries Science Education Shanghai Ocean UniversityShanghai201306China Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of AgricultureShanghai Ocean UniversityShanghai201306China Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding Shanghai Ocean UniversityShanghai201306China

Zooplanktons are important food organisms of fishes,and their spatial and temporal distribution pattern has an important influence on the growth and reproduction of fishes in local *** yangtze River estuary of China is rich in fishery resources,but the knowledge on the distribution pattern of zooplankton in this area is still very *** diel vertical migration(DVM)patterns and seasonal variations of the crustacean community,and their relationship with environmental factors were investigated in the south branch of the yangtze estuary,from June 2017 to May *** results showed that the dispersion patterns of dominant crustacean taxa in the yangtze estuary were mostly *** amplitudes of crustacean were greater in spring and summer than in autumn and winter,and different migratory patterns occurred in different *** dorrii,Schmackeria inopinus,Mesmackeria leuckarti,Bosmina longirostris,and ***,unlike ***,showed a significant *** DVM patterns of crustaceans was possibly influenced by light dentisy,temperature,and total dissolved solids in the water column,and the fish predation effect;whereas,the nutrient concentration and pH were not supposed to be key factors.

关键词： yangtze estuary Planktonic crustacean Dispersion pattern Diel vertical migration

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Journal of Geographical Sciences 2002年第4期12卷 489-494页

作者： LI Yuzhong, CHEN Shenliang(State Key Laboratory of Estuarine && Coastal Research, East China Normal University, Shanghai 200062, China) East China Normal University State Key Laboratory of Estuarine & Coastal Research Shanghai China (GRID:grid.22069.3f) (ISNI:***)

By analysis of published papers on the yangtze estuary and hydrological and sediments data in Yangshan Harbor area, many similarities are found between Yangshan Harbor area and the yangtze estuary. These similarities include the phenomenon of stagnating flow areas, the distributive characteristics of the highest suspended sediment concentration areas, superficial sediments and shoal bars. The stagnating flow area is the major similarity which causes other similarities. These similarities indicate that: 1) Turbidity Maximum and mouth bars in estuaries are mainly caused by the hydraulic balance of stagnating flow areas of estuaries; 2) The stagnating sand area of sands caused by stagnating flow area often locates on the narrower side of the stagnating flow area; 3) The location (or shape) of fine sediments area caused by stagnating flow area reflects the location (or shape) of the stagnating flow area. Both Yangshan Harbor area and the yangtze estuary are the important developmental areas in the future (man-made similarity). In-depth studies on these similarities between Yangshan Harbor area and the yangtze estuary will have momentous theoretical and practical significance.

关键词： Yangshan Harbor yangtze estuary similarity stagnating flow area turbidity maximum mouth bar

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Heavy metals and phosphorus in tidal flat sediments of the yangtze estuary

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Journal of Geographical Sciences 2002年第4期12卷 472-478页

作者： GAO Xiaojiang1, CHEN Zhenlou2, ZHANG Nianli1, XU Shiyuan2, CHEN Limin1(1. Dept. of Environmental Science and Engineering, Fudan University, Shanghai 200433, China 2. Department of Geography, East China Normal University, Shanghai 200062, China) Dept. of Environmental Science and Engineering Fudan University Shanghai China Department of Geography East China Normal University Shanghai China

Concentrations of heavy metals (Cu, Pb, Zn, Cr and Cd), and phosphorous (P) were determined in surface tidal flat sediments of the yangtze estuary and Shanghai coast. Results demonstrate that there were significant differences among the accumulation of the heavy metals in sediments, following the order: Zn > Cu > Cr > Pb > Cd. The spatial distribution and chemical forms of heavy metals in tidal flat sediments were closely related to the distribution of pollution resources (outlet of sewage) and the local sedimentary and hydrodynamic conditions. The dominated form of non-residual heavy metals is bound to Fe/Mn oxides, and the next form is bound to carbonates. Moreover, contents of total P in sediments range from 18.0 μmol.g?1 to 31.4 μmol.g?1 along the coastline, speciation of P in sediments was different, most of P in tidal flat sediments is associated with calcium phases (as Ca-P) similar to marine sediments.

关键词： heavy metals phosphorus tidal flat sediments yangtze estuary

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Evaluation of dissolved inorganic nitrogen eliminating capability of the sediment in the tidal wetland of the yangtze estuary

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Journal of Geographical Sciences 2009年第4期19卷 447-460页

作者：王军陈振楼王东启孙小静许世远 Key Laboratory of Geo-information Science of the Ministry of Education East China Normal University School of Resources and Environment Science East China Normal University

Estuarine wetlands serve as a natural barrier to remove the land-generated pollutants and attenuate the pollutant load from the land to the sea. As one of the most important estuarine wetlands, the yangtze estuarine wetlands have attracted particular interests in the biogeochemical studies of nutrients. The objectives of this study were to characterize the seasonal and spatial distribution of dissolved inorganic nitrogen （DIN） fluxes across the sediment-water interface; to calculate the total DIN fluxes in a year and different seasons; and to evaluate the DIN removing capability of the sediment in the tidal wetlands of the yangtze estuary. The spatial distribution of DIN fluxes shows complicated seasonal variations and spatial differences. The annual DIN fluxes range from -22.22 mmol N m^-2 h^-1 to 19.54 mmol N m^-2 h^-1, with an average of -1.48±1.34 mmol N mm^-2 h^-1. The tidal wetlands in the yangtze estuary behave as a source of water DIN in spring when DIN is released from sediment into overlying water, and the released amount of DIN is 1.33×10^4 tons of nitrogen （T N）. In summer, autumn and winter, the sediment absorbs the DIN from the overlying water, and the absorbed amounts of DIN are 4.36×10^4 T N, 6.81×10^4 T N and 2.24×10^4 T N, respectively. The average amount of DIN in overlying water of the yangtze estuary is 52.6×10^4 T N yr^-1, and the perennial average amount of DIN absorbed from the overlying water by the sediment is 12.1 × 10^4 T N yr^-1. The annual DIN elimination rate of the tidal wetlands was 23.0%.

关键词： nitrogen eliminating capability wetlands estuarine environment yangtze estuary

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