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Sampling Surface Particle Size Distributions and Stability Analysis of Deep Channel in the pearl river estuary

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China Ocean Engineering 2017年第3期31卷 299-307页

作者： FENG Hao-chuan ZHANG Wei ZHU Yu-liang LEI Zhi-yi JI Xiao-mei State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 China

Particle size distributions （PSDs） of bottom sediments in a coastal zone are generally multimodal due to the complexity of the dynamic environment. In this paper, bottom sediments along the deep channel of the pearl river estuary （PRE） are used to understand the multimodal PSDs＇ characteristics and the corresponding depositional environment. The results of curve-fitting analysis indicate that the near-bottom sediments in the deep channel generally have a bimodal distribution with a fine component and a relatively coarse component. The particle size distribution of bimodal sediment samples can be expressed as the sum of two lognormal functions and the parameters for each component can be determined. At each station of the PRE, the fine component makes up less volume of the sediments and is relatively poorly sorted. The relatively coarse component, which is the major component of the sediments, is even more poorly sorted. The interrelations between the dynamics and particle size of the bottom sediment in the deep channel of the PRE have also been investigated by the field measurement and simulated data. The critical shear velocity and the shear velocity are calculated to study the stability of the deep channel. The results indicate that the critical shear velocity has a similar distribution over large part of the deep channel due to the similar particle size distribution of sediments. Based on a comparison between the critical shear velocities derived from sedimentary parameters and the shear velocities obtained by tidal currents, it is likely that the depositional area is mainly distributed in the northern part of the channel, while the southern part of the deep channel has to face higher erosion risk.

关键词： multimodality particle size distribution tidal currents potential erosion pearl river estuary

Spectral characteristics of dissolved organic matter in sediment pore water from pearl river estuary

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Science China Earth Sciences 2021年第1期64卷 52-61页

作者： Yang XU Penghui LI Chuanlun ZHANG Peng WANG State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Shenzhen Key Laboratory of Marine Archaea Geo-Omics Department of Ocean Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China

As key parts of land-sea transition zones,estuary ecosystems play a very important role in the ocean carbon cycle *** sources,degradation,and preservation of dissolved organic matter(DOM)in estuaries have long been the subject of intense *** examine the aforementioned issues,this study examined three-dimensional fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy to determine the spatial distribution and sources of DOM in the pore water of three sedimentary cores from the pearl river estuary(S1,S2 and S3,with increasing salinity).Using the parallel factor analysis(PARAFAC)method to analyze the three-dimensional fluorescence spectrum data,five fluorescent components were obtained—three humic-like components(C1,C3,and C4),and two protein-like components(C2 and C5).C2 exhibited a significant positive correlation with the sediment microbial deoxyribose nucleic acid(DNA)concentration(R~2=0.69,P<0.01),indicating that the protein-like component C2 might be derived from the catabolism of in situ microbes.C5 displayed a relatively weak correlation with DNA concentration(R~2=0.40,P<0.05),presumably due to the incorporation of phenolic compounds,which have a fluorescence peak very similar to that of protein-like *** source of humic-like fluorescent components is extremely *** content at station S1 was relatively high(1.45–8.83 R.U.),which implies that terrestrial inputs had a significant *** three humic-like components showed similar distributions at S2 and S3,and the fluorescence intensity was rather low;this result indicates that the DOM at these two stations was more likely affected by the metabolism of algae and *** humification index(HIX)and the fluorescence intensity of protein-like components increased and decreased,respectively,with *** was a significant positive correlation between the relative content of protein-like components and the spectral slope ratio(SR),which indicates tha

关键词： pearl river estuary Sediment DOM Three-dimensional fluorescence spectroscopy Ultraviolet-Visible absorption spectroscopy

Numerical Simulation and Risk Analysis of Coastal Inundation in Land Reclamation Areas:A Case Study of the pearl river estuary

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Journal of Ocean University of China 2020年第6期19卷 1221-1234页

作者： DU Mei HOU Yijun GUO Yunxia WANG Kai Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory for Ocean and Climate Dynamics Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Coastal inundation results in many human casualties and significant economic *** this study,an inundation model with an unstructured mesh was developed using the ADvanced CIRCulation(ADCIRC)and Simulating WAves Nearshore(SWAN)models to simulate 43 inundation events from 1998 to 2018.A combined wind-pressure field derived from the assimilation windpressure model was used to drive the coupled ADCIRC-SWAN *** the basis of the model results,a sensitivity study of the influence of land reclamation on coastal inundation was *** results of the study showed that coastline changes caused by reclamation significantly influence the distribution of coastal inundation,particularly in areas where narrow waterways,bays,and peninsulas are newly *** the extreme inundation events calculated using the Gumbel and Weibull distributions,the 10-year,50-year,100-year,and 200-year return coastal inundations were obtained for the pearl river estuary in *** risk of coastal inundation was analyzed according to the probability of the inundation depth exceeding 1 m.A hazard grade zoning map was drawn to guide disaster relief and mitigation in the reclamation area.

关键词： coupled ADCIRC-SWAN model coastline change coastal inundation pearl river estuary risk analysis

Modified optical remote sensing algorithms for the pearl river estuary

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Frontiers of Earth Science 2015年第4期9卷 732-741页

作者： Man-Chung CHIM Jiayi PAN Wenfeng LAI Institute of Space and Earth Information Science The Chinese University of Hong Kong Hong Kong SAR China

This study aims to develop new algorithms to retrieve sea surface parameters including concentrations of Chlorophyll a （Chl a） and Suspended Particulate Matter （SPM）, and absorbance of Colored Dissolved Organic Matter （aCDOM） by incorporating the contribution of red bands to make them more adaptable to case 2 waters. Optical remote sensing algorithms have demonstrated efficient retrieval of Chl a, SPM, and aCDOM, yet they are not very accurate especially for coastal areas. It has also been found that the default algorithm has overestimated Chl a in the pearl river estuary, and shown poor correlation for CDOM absorbance. By incorporating the red band ratios into the algorithm, a correction effect has been shown, which improves the accuracy of quantifying the actual concentration. Modeling and data fitting of the algorithm have been done based on 61 data samples collected in the pearl river estuary during a cruise from 3 to 11 May 2014. The study also attempts to modify the aerosol correction bands used in SeaDAS to prevent saturation of these bands. The modified algorithms showed an R-Square value of 0.7289 for Chl a fitting, and 0.7338 for CDOM fitting, and corrected overestimation of Chl a concentration in the pearl river estuary.

关键词： optical remote sensing algorithm pearl river estuary

Distribution Characteristics and Sources of Sedimentary Organic Matter in the pearl river estuary and Adjacent Coastal Waters,Southern China

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Journal of Earth Science 2013年第2期24卷 262-273页

作者：张凌殷克东杨永强张德荣 State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of Sciences School of Marine Sciences Sun Yat-Sen University Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Geochemical descriptors （carbon, nitrogen contents, and their isotopes） of sedimentary organic matter （OM） were investigated in the pearl river estuary （PRE） and adjacent coastal *** comprehensive geochemical data of surface and deep sediments were provided, and the sources of sedimentary OM were discussed in this area mainly impacted by human activities. Surface （1-10 cm）and deep （190-200 cm） sedimentary total organic carbon （TOC） were 1.2% and 0.6%, and total nitrogen （TN） contents were 0.09% and 0.05%, with δ^13C of-24.3%0 and -24.5%0, on the average, *** TOC and TN contents combining with relatively negative 613C values in surface sediments suggested the increasing OM inputs from rivers in recent years. Terrestrial organic carbon （OC） contents were 0.70% and 0.36%, and marine OC contents were 0.50% and 0.28% on the average, respectively, in surface and deep sediment. Surface terrestrial and marine OC were lower in river outfalls due to the high current energy, and deep terrestrial and marine OC showed the increasing trend away from the coast. Lower δ^15 was mainly attributed to the influence of river sewage discharge in this study.

关键词： organic matter concentration isotope pearl river estuary

Estimation of Turbulent Kinetic Energy Dissipation Rate in the Bottom Boundary Layer of the pearl river estuary

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China Ocean Engineering 2011年第4期25卷 669-678页

作者：刘欢吴超羽任杰 Research Center of Coastal Ocean Science and Technology Sun Yat-sen University School of Environmental Science and Engineering Sun Yat-sen University School of Marine Science Sun Yat-sen University

A structure function approach is applied to estimate the turbulent kinetic energy （TKE） dissipation rate in the bottom boundary layer of the pearl river estuary （PRE）. Simultaneous measurements with an acoustic Doppler velocimeter （ADV） supplied independent data for the verification of the structure function method. The results show that, 1） the structure function approach is reliable and successfully applied method to estimate the TKE dissipation rate. The observed dissipation rates range between 8.3 ×10^-4 W/kg and 4.9× 10^-6 W/kg in YM01 and between 3.4×10^-4 W/kg and 4.8×10^-7 W/kg in YM03, respectively, while exhibiting a strong quarter-diurnal variation. 2） The balance between the shear production and viscous dissipation is better achieved in the straight river. This first-order balance is significantly broken in the estuary by non-shear production/dissipation due to wave-induced fluctuations.

关键词： structure function turbulent kinetic energy dissipation rate bottom boundary layer pearl river estuary

Multilocus DNA metabarcoding diet analyses of small cetaceans:a case study on highly vulnerable humpback dolphins and finless porpoises from the pearl river estuary,China

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Integrative Zoology 2023年第1期18卷 183-198页

作者： Xiyang ZHANG Dingyu LUO Ri-Qing YU Yuping WU School of Marine Sciences Zhuhai Key Laboratory of Marine Bioresources and EnvironmentGuangdong Provincial Key Laboratory of Marine Resources and Coastal EngineeringPearl River Estuary Marine Ecosystem Research StationMinistry of EducationSun Yat-sen UniversitySouthern Marine Science and Engineering Guangdong LaboratoryZhuhaiChina Department of Biology Center for EnvironmentBiodiversity and ConservationThe University of Texas at TylerTylerTexasUSA

Accurate diet identiﬁcation of top predators is crucial to fully understand their ecological *** to terrestrial animals,gathering dietary information from cetaceans is notoriously difﬁ***,we applied a multilocus metabarcoding approach to investigate the diet of vulnerable Indo-Paciﬁc humpback dolphins and Indo-Paciﬁcﬁnless porpoises from the pearl river estuary(PRE),*** analyses identiﬁed 21 preyﬁsh species from the 42 humpback dolphin stomachs,as well as 10 species ofﬁsh and 1 species of cephalopod from the 13ﬁnless porpoise *** of the taxa were assigned to the species level,highlighting that the multimarker approach could facilitate species identiﬁ*** of the prey species were small-and medium-sizedﬁshes that primarily fed on *** calculated similarity index revealed a moderated dietary overlap between the 2 cetaceans,presumably due to the feeding of the 2 predators in association withﬁshing vessels in the PRE.A more diverse diet was observed in humpback dolphins in the closedﬁshing season compared to theﬁshing season,implying the inﬂuence on the dolphin diet due to the availability of commercialﬁshery ***,according to the results of species rarefaction curves,ourﬁndings on the feeding habits of the 2 cetaceans are still limited by insufﬁcient sample size and therefore should be interpreted with *** study represents aﬁrst attempt to apply the multilocus DNA metabarcoding technique in the diet analysis of small cetaceans,although more efforts are needed to improve this type of analysis.

关键词： diet species analyses DNA metabarcoding Indo-Paciﬁcﬁnless porpoise Indo-Paciﬁc humpback dolphin pearl river estuary

Statistical Modeling and Trend Detection of Extreme Sea Level Records in the pearl river estuary

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Advances in Atmospheric Sciences 2017年第3期34卷 383-396页

作者： Weiwen WANG Wen ZHOU School of Architecture The Chinese University of Hong KongHong KongChina Guy Carpenter Asia-Pacific Climate Impact Centre School of Energy and EnvironmentCity University of Hong KongHong KongChina City University ofHong Kong Shenzhen Research Institute Shenzhen 518057China

Sea level rise has become an important issue in global climate change studies. This study investigates trends in sea level records, particularly extreme records, in the pearl river estuary, using measurements from two tide gauge stations in Macao and Hong Kong. Extremes in the original sea level records （daily higher high water heights） and in tidal residuals with and without the 18.6-year nodal modulation are investigated separately. Thresholds for defining extreme sea levels are calibrated based on extreme value theory. Extreme events are then modeled by peaks-over-threshold models. The model applied to extremes in original sea level records does not include modeling of their durations, while a geometric distribution is added to model the duration of extremes in tidal residuals. Realistic modeling results are recommended in all stationary models. Parametric trends of extreme sea level records are then introduced to nonstationary models through a generalized linear model framework. The result shows that, in recent decades, since the 1960s, no significant trends can be found in any type of extreme at any station, which may be related to a reduction in the influence of tropical cyclones in the region. For the longer-term record since the 1920s at Macao, a regime shift of tidal amplitudes around the 1970s may partially explain the diverse trend of extremes in original sea level records and tidal residuals.

关键词： sea level rise extreme climate change extreme value theory pearl river estuary

Dynamics of saltwater intrusion in the Modaomen Waterway of the pearl river estuary

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Science China Earth Sciences 2012年第11期55卷 1901-1918页

作者： WANG Biao ZHU JianRong WU Hui YU FuJiang SONG XueJia State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China National Marine Environmental Forecasting Center Beijing 100081China

Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the pearl river estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring *** explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the pearl river estuary,and the adjacent *** experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the *** topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring *** a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate *** is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate ***,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.

关键词： pearl river estuary Modaomen Waterway saltwater intrusion abnormal characteristic dynamic mechanism