Morphological evolution of a large sand bar in the Qiantang River Estuary of China since the 1960s

Huang, Junbao; Sun, Zhilin; Xie, Dongfeng

doi:10.1007/s13131-021-1817-z

Cited by 11 publications

(2 citation statements)

References 33 publications

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“…Fonte: autores (2023). Mudanças morfológicas de barras recentes em sistemas fluviais de mundo, como nos rios Qiantang (China), Colorado (Estados Unidos) e Jaguaribe (Brasil) tem sido associadas, em parte, a fatores climáticos (HUANG et al 2022;QUEIROZ et al 2018;WRIGHT et al 2011), os quais são diretamente vinculados às variações nas taxas de precipitação ao longo dos anos e podem ocasionar mudanças no padrão de sazonalidade da rede de drenagem.…”

Section: Resultados E Discussõesunclassified

Caracterização Multitemporal De Barras Fluviais No Arquipélago De Mariuá, Médio Rio Negro , Amazonas

Jesus de Souza,

Alberto Amaral Soares,

Hatsue Tatumi

et al. 2024

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Este trabalho apresenta a evolução morfológica de barras arenosas da porção oeste do Arquipélago de Mariuá, médio curso do Rio Negro. Apesar desse arquipélago ser considerado o maior do planeta, estudos referentes à última fase de sedimentação das ilhas e barras ainda são escassos, principalmente relacionados aos processos de erosão e sedimentação. Foram utilizadas ferramentas de sensoriamento remoto, através da análise multitemporal de imagens Landsat, para o entendimento da evolução morfológica das barras arenosas no intervalo temporal de 31 anos (1985 - 1997 - 2016). No primeiro período (1985 - 1997) a taxa de erosão foi maior que a deposição, enquanto no segundo período (1997 - 2016) predominou a dinâmica deposicional acrescionária, ambas relacionadas a variação do aporte sedimentar. Com base nos resultados obtidos, o aumento ou a diminuição do aporte sedimentar foi relacionado com as mudanças morfológicas das barras arenosas, bem como aos períodos de maior e menor precipitação, que refletem as características dos fenômenos El Nino e La Nina na Amazônia. Particularmente, foi possível evidenciar a relação do aumento no aporte sedimentar, indicado pelos dados da carga de sedimentos em suspensão (CSS), descarga sólida e análise multitemporal das barras, com o fenômeno La Nina, que influenciou no aumento na taxa de precipitação na Bacia do Rio Negro. Apesar da análise multitemporal das barras no arquipélago envolverem um intervalo de tempo recente e curto (31 anos), o resultado pontual de datação por Luminescência Opticamente Estimulada (LOE) indica que a sedimentação das barras iniciou há pelo menos cinco (05) séculos.

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Section: Resultados E Discussõesunclassified

Caracterização Multitemporal De Barras Fluviais No Arquipélago De Mariuá, Médio Rio Negro , Amazonas

Jesus de Souza,

Alberto Amaral Soares,

Hatsue Tatumi

et al. 2024

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“…The Caofeidian shoal, formerly a part of the Luanhe River Delta, has undergone transformation into a barrier island-lagoon system as a result of wave and tidal erosion [30,31]. This lagoon experiences irregular semidiurnal mixed tides, with an average water depth ranging from 0 to 5 m and a tidal flat width spanning 15 to 25 km [32,33].…”

Section: Study Sitementioning

confidence: 99%

Coastal Ecological Connectivity between Seagrass Bed and Marine Ranching 30 km Apart: A Case STUDY of Apostichopus japonicus Feeding on Seagrass Debris in the Bohai Sea, China

Xu,

Wang,

Yue

et al. 2024

Sustainability

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Coastal ecosystems form interconnected networks that are essential for the maintenance of marine biodiversity. This study investigates the dietary patterns of Apostichopus japonicus (sea cucumber) within a marine ranching ecosystem and reveals the influence of Zostera marina (seagrass) leaves from a distant bed on nutrient availability and trophic connectivity. Samples collected between September 2020 and March 2021 from Xiangyun Bay included A. japonicus, macroalgae, phytoplankton, and seagrass leaves. Stable isotope analysis (δ13C and δ15N), in conjunction with Bayesian mixing models, elucidated the contributions of different food sources to A. japonicus’ diet. Macroalgae constituted more than 50% of A. japonicus’ diet, while seagrass contributions ranged between 5.7% and 11.3%. The isotopic analysis confirmed the presence of seagrass debris in the marine ranching environment, indicating significant nutrient transport from a remote seagrass bed. This study underscores the crucial role played by macroalgae as the primary source of nutrients for A. japonicus within a marine ranching setting. Furthermore, detecting seagrass debris from a distant habitat highlights previously unrecognized ecological connectivity between seagrass ecosystems and artificial reef environments along coastal areas. This understanding of long-range nutrient transfers is vital for effective management and conservation strategies in coastal marine systems, emphasizing intricate yet significant ecological interdependencies across coastal environments.

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Remote‐Sensing Estimation of Phytoplankton Size Classes FromGOCISatellite Measurements in Bohai Sea and Yellow Sea

et al. 2017

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Phytoplankton size class (PSC), a measure of different phytoplankton functional and structural groups, is a key parameter to the understanding of many marine ecological and biogeochemical processes. In turbid waters where optical properties may be influenced by terrigenous discharge and nonphytoplankton water constituents, remote estimation of PSC is still a challenging task. Here based on measurements of phytoplankton diagnostic pigments, total chlorophyll a, and spectral reflectance in turbid waters of Bohai Sea and Yellow Sea during summer 2015, a customized model is developed and validated to estimate PSC in the two semienclosed seas. Five diagnostic pigments determined through high‐performance liquid chromatography (HPLC) measurements are first used to produce weighting factors to model phytoplankton biomass (using total chlorophyll a as a surrogate) with relatively high accuracies. Then, a common method used to calculate contributions of microphytoplankton, nanophytoplankton, and picophytoplankton to the phytoplankton assemblage (i.e., Fm, Fn, and Fp) is customized using local HPLC and other data. Exponential functions are tuned to model the size‐specific chlorophyll a concentrations (Cm, Cn, and Cp for microphytoplankton, nanophytoplankton, and picophytoplankton, respectively) with remote‐sensing reflectance (Rrs) and total chlorophyll a as the model inputs. Such a PSC model shows two improvements over previous models: (1) a practical strategy (i.e., model Cp and Cn first, and then derive Cm as C‐Cp‐Cn) with an optimized spectral band (680 nm) for Rrs as the model input; (2) local parameterization, including a local chlorophyll a algorithm. The performance of the PSC model is validated using in situ data that were not used in the model development. Application of the PSC model to GOCI (Geostationary Ocean Color Imager) data leads to spatial and temporal distribution patterns of phytoplankton size classes (PSCs) that are consistent with results reported from field measurements by other researchers. While the applicability of the PSC model together with its parameterization to other optically complex regions and to other seasons is unknown, the findings of this study suggest that the approach to develop such a model may be extendable to other cases as long as local data are used to select the optimal band and to determine the model coefficients.

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Morphological evolution of a large sand bar in the Qiantang River Estuary of China since the 1960s

Cited by 11 publications

References 33 publications

Caracterização Multitemporal De Barras Fluviais No Arquipélago De Mariuá, Médio Rio Negro , Amazonas

Caracterização Multitemporal De Barras Fluviais No Arquipélago De Mariuá, Médio Rio Negro , Amazonas

Coastal Ecological Connectivity between Seagrass Bed and Marine Ranching 30 km Apart: A Case STUDY of Apostichopus japonicus Feeding on Seagrass Debris in the Bohai Sea, China

Remote‐Sensing Estimation of Phytoplankton Size Classes FromGOCISatellite Measurements in Bohai Sea and Yellow Sea

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