Anthropocene Coasts最新文献_第10页

Contrast of fine sediment dynamics between shoals and channels in a microtidal estuary with mixed semi-diurnal tides 半日潮混合微潮河口浅滩和河道细泥沙动力学对比

Anthropocene Coasts Pub Date : 2023-02-24 DOI: 10.1007/s44218-023-00018-6

Wenping Gong, Jiaxi Wang, Junpeng Zhao, Lianghong Chen, Heng Zhang

{"title":"Contrast of fine sediment dynamics between shoals and channels in a microtidal estuary with mixed semi-diurnal tides","authors":"Wenping Gong, Jiaxi Wang, Junpeng Zhao, Lianghong Chen, Heng Zhang","doi":"10.1007/s44218-023-00018-6","DOIUrl":"10.1007/s44218-023-00018-6","url":null,"abstract":"<div><p>Estuaries usually feature complex bathymetries, where shoals and channels are co-existent. Due to the differences in water depth, current, density gradient and therefore stratification, sediment dynamics on the shoal and in the channel demonstrate significant variations. In this study, field measurements were carried out during spring and neap tides in both wet and dry seasons in the Huangmaohai Estuary, a microtidal estuary located in the southwest of the Pearl River Delta. Harmonic analysis was conducted for the timeseries data of current and suspended sediment concentration (SSC) for each deployment. Sediment transport flux was decomposed into an advective component, and tidal pumping fluxes by different tidal constituents. During the neap tides, sediment transport is primarily controlled by the advective flux, whereas during the spring tides, tidal pumping fluxes become comparable to, sometimes even exceeding, the advective one. For a 25-hr period, the M1 component of SSC usually denotes the maximum SSC associated with the highest bottom stress, while the M2 component signifies the two highs of the SSC. The M4 component is generally insignificant. The M1 and M2 components can be induced by both the advection and bottom resuspension. For the resuspension part, the M1 component is mostly induced by tidal velocity asymmetry, while the M2 component is generated by tidal straining effect. Sediment transport at the shoal is mostly controlled by the advective flux and the tidal pumping due to tidal velocity asymmetry, while that in the channel is dictated by advective transport and the tidal pumping due to tidal mixing asymmetry.</p></div>","PeriodicalId":100098,"journal":{"name":"Anthropocene Coasts","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Suspended sediment dynamics and influencing factors during typhoons in Hangzhou Bay, China 杭州湾台风期间悬沙动力学及其影响因素

Anthropocene Coasts Pub Date : 2023-02-06 DOI: 10.1007/s44218-023-00019-5

Ju Huang, Jianrong Zhu

引用次数: 0

Suspended sediment dynamics and influencing factors during typhoons in Hangzhou Bay, China 杭州湾台风期间悬浮泥沙动力学及其影响因素

Anthropocene Coasts Pub Date : 2023-02-06 DOI: 10.1007/s44218-023-00019-5

Ju Huang, Jianrong Zhu

{"title":"Suspended sediment dynamics and influencing factors during typhoons in Hangzhou Bay, China","authors":"Ju Huang, Jianrong Zhu","doi":"10.1007/s44218-023-00019-5","DOIUrl":"10.1007/s44218-023-00019-5","url":null,"abstract":"<div><p>Hangzhou Bay is located in China on the south side of the Changjiang Estuary and is vulnerable to extreme weather, such as typhoons in the summer and autumn. In this study, a three dimensional suspended sediment numerical model was developed that considers the dynamic factors of advection, mixing, wave, and sediment-induced stratification to simulate and analyze the effect of typhoons on water and sediment transport in Hangzhou Bay. The model validations show that the model can sufficiently reproduce the variability of the suspended sediment concentration (SSC) during typhoon conditions. The simulation results show that the high SSC in the bottom layer was mainly distributed in the leading edge of the south coast, and generally exceeded 10 kg·m<sup>−3</sup>. During typhoons, the water and suspended sediment transport in Hangzhou Bay presented a pattern of \"north-landward and south-seaward\" circulation, which promoted the convergence of suspended sediment in the center part of the bay. During Typhoon Rumbia in 2018, the water and sediment flux across the section from Nanhui Cape to Qiqu Archipelago (NQ section) increased by 18.13% and 265.75%, respectively, compared with those before the typhoon. The wave-induced bottom shear stress during typhoons has a very significant impact on the bottom SSC. The sensitivity experiments show that the wave-induced bottom shear stress greatly promotes the sediment resuspension during typhoons, which indirectly makes the sediment-induced stratification stronger than the direct effect of waves on the vertical mixing. The strong winds brought by typhoons mainly enhanced the vertical mixing, which has a stronger effect on surface SSC than waves. The suppression of vertical mixing by sediment-induced stratification during typhoons should not be ignored, especially for high turbidity coastal waters, such as Hangzhou Bay.</p></div>","PeriodicalId":100098,"journal":{"name":"Anthropocene Coasts","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modulation of sediment load recovery downstream of Three Gorges Dam in the Yangtze River 长江三峡大坝下游泥沙负荷恢复的调节

Anthropocene Coasts Pub Date : 2023-01-20 DOI: 10.1007/s44218-022-00015-1

Chunyan Zhu, Yuning Zhang, D. V. van Maren, W. Xie, Leicheng Guo, Xianye Wang, Qing He

引用次数: 1

Modulation of sediment load recovery downstream of Three Gorges Dam in the Yangtze River 长江三峡大坝下游调沙工程

Anthropocene Coasts Pub Date : 2023-01-20 DOI: 10.1007/s44218-022-00015-1

Chunyan Zhu, Yuning Zhang, Dirk Sebastiaan van Maren, Weiming Xie, Leicheng Guo, Xianye Wang, Qing He

{"title":"Modulation of sediment load recovery downstream of Three Gorges Dam in the Yangtze River","authors":"Chunyan Zhu, Yuning Zhang, Dirk Sebastiaan van Maren, Weiming Xie, Leicheng Guo, Xianye Wang, Qing He","doi":"10.1007/s44218-022-00015-1","DOIUrl":"10.1007/s44218-022-00015-1","url":null,"abstract":"<div><p>The sediment load in the Yangtze River downstream of the Three Gorges Dam (TGD) has substantially declined in recent decades. The decrease is more profound below the TGD, e.g., a 97% decrease at Yichang, compared with that at the delta apex, 1200 km downstream, e.g., a 75% decrease, implying along-river sediment recovery. Two large river-connected lakes, i.e., Dongting and Poyang Lakes, may play a role in the re-establishment of the river’s morphodynamic equilibrium, but a quantitative data-based understanding of this interaction is not yet available. In this work, we collected a series of field data to quantify the sediment gain and loss in the river-lake system in the middle-lower Yangtze River, and evaluate the lake’s response to the reduction in riverine sediment supply. We find that Dongting Lake and Poyang Lake shifted from net sedimentation to erosion in 2006 and 2000, and back to a sedimentation regime again after 2017 and 2018, respectively. Natural morphodynamic adaptation and sand mining play an important role in the regime changes in the Dongting Lake whereas sand mining dominates the abrupt changes in the Poyang Lake. The Dongting and Poyang Lake contributed maximum by 38% (2015) and 17% (2006) (respectively) to the sediment recovery in the erosion regime, whereas the riverbed erosion dominates the main sediment source. These changes in the relative contribution of sediment sources also indicates a response time of ~ 20 years in the lakes towards a new equilibrium state. It is noteworthy that the lakes’ buffer effects may be overestimated as the supplied sediment from the lakes is rather small compared to the significant dam trapping in the upstream basin and sediment source from downstream degradation. The results imply that river management and restoration should take into account of the river-lake interactions and feedback impact at decadal time scales.</p></div>","PeriodicalId":100098,"journal":{"name":"Anthropocene Coasts","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71910461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Evaluation on the tracer simulation under different advection schemes in the ocean model 海洋模式中不同平流方案下示踪剂模拟的评价

Anthropocene Coasts Pub Date : 2023-01-12 DOI: 10.1007/s44218-023-00017-7

Hui Wu

{"title":"Evaluation on the tracer simulation under different advection schemes in the ocean model","authors":"Hui Wu","doi":"10.1007/s44218-023-00017-7","DOIUrl":"10.1007/s44218-023-00017-7","url":null,"abstract":"<div><p>Advection scheme is one of the core challenges in the computational fluid dynamics, which restricts the capacity of model performance in many research areas including the oceanographic modelling studies. Here in this study, we compared the newly developed algorithm HSIMT (advection scheme with High-order Spatial Interpolation at the Middle Temporal level) with the well-known scheme MPDATA (Multidimensional Positive-Definite Advective Transport Algorithm), in the 1-dimensional idealized simulation and the 3-dimensional realistic river plume simulations. The river plume simulation was done with a mainstream ocean model ROMS (Regional Ocean Modeling System). The results showed that in the 1-dimensional test both HSIMT and MPDATA can converge to the analytical results, but HSIMT converges much faster and does not produce overshooting around the sharp front. Accuracy of HSIMT is also free from the choice of timestep, unlike MPDATA. In the ROMS simulation of a surface-trapped river plume, HSIMT also showed great advantages. Results simulated by MPDATA is highly relied on the model resolution, but when the resolution is high enough the results approached to that simulated by HSIMT. The results of this study could assist the further understanding on capacity of advection schemes and further promote the developments of ocean models.</p></div>","PeriodicalId":100098,"journal":{"name":"Anthropocene Coasts","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation on the tracer simulation under different advection schemes in the ocean model 不同平流方案下海洋模式示踪模拟的评价

Anthropocene Coasts Pub Date : 2023-01-12 DOI: 10.1007/s44218-023-00017-7

Hui Wu

引用次数: 0

Correction: Study of an abnormally strong saltwater intrusion in the Humen Channel of the Pearl River estuary 更正：珠江口虎门海峡异常强烈盐水入侵的研究

Anthropocene Coasts Pub Date : 2022-12-30 DOI: 10.1007/s44218-022-00016-0

Jiaxi Wang, Bo Hong, Wenping Gong

引用次数: 0

Book review: High-resolution seafloor survey and applications, Eds. Wu, Ziyin, Yang, Fanlin, and Tang, Yong, 2021. Springer Nature and Science Press. https://doi.org/10.1007/978-981-15-9750-3 书评：《高分辨率海底探测与应用》，吴、紫音、杨、范琳、唐、勇主编，2021。施普林格自然与科学出版社。https://doi.org/10.1007/978-981-15-9750-3

Anthropocene Coasts Pub Date : 2022-12-14 DOI: 10.1007/s44218-022-00013-3

Ian Townend, Zeng Zhou