scholarly journals Drag variations, tidal asymmetry and tidal range changes in a mangrove creek system

2021 ◽  
Author(s):  
E. M. Horstman ◽  
K. R. Bryan ◽  
J. C. Mullarney
Keyword(s):  
Tidal Range ◽  
Tidal Asymmetry ◽  
Mangrove Creek

Influences of River Discharge Variation and Tidal Asymmetry on the Spatial Evolution of the Turbidity Maximum Zone in Yangtze Estuary

2020 ◽  
Author(s):  
Ping Dong ◽  
Huabin Shi
Keyword(s):  
River Discharge ◽  
Yangtze Estuary ◽  
Turbidity Maximum ◽  
Tidal Range ◽  
Tidal Asymmetry ◽  
Interannual Variations ◽  
The South ◽  
Turbidity Maximum Zone ◽  
Averaged Model ◽  
Seasonal And Interannual Variations

<p>The Yangtze estuary is characterized by its extremely high suspended sediment concentration (SSC) and the extensive turbidity maximum zone (TMZ). The estuary is physically forced by an upstream river discharge seasonally varying in a wide range of 6000 – 92000 m3/s and semidiurnal-diurnal mixed tides with the tidal range up to 5 m. The influences of the seasonal and interannual variations in the upstream river discharge and the tidal asymmetry on the location of the Yangtze TMZ are numerically investigated with a two-dimensional depth-averaged model. Sensitivities of SSC and hence the location of TMZ to the bottom shear stress, bed erodibility, and the sediment settling velocity are studied. The spatial and temporal evolutions of the TMZ position in the cases of various upstream river discharges with different monthly, seasonal and interannual variations are simulated and discussed. The effects of the M2/M4-induce tidal asymmetry on the TMZ position and those of the interactions between the eight main astronomical tides (M2, S2, N2, K2, K1, O1, P1, and Q1) are compared. It is shown that the M2/M4-induce tidal asymmetry plays a critical role in the formulation of TMZ in the downstream of the South Branch of Yangtze estuary, while the interactions between the eight main astronomical tides have more significant effects on the TMZ location in other areas of Yangtze estuary such as the South and the North Passages.</p>

Nitrogen concentrations in a mangrove creek with a large tidal range, Peninsular Malaysia

Hydrobiologia ◽  
1993 ◽  
Vol 254 (2) ◽  
pp. 125-132 ◽  
Author(s):  
K. L. Thong ◽  
A. Sasekumar ◽  
N. Marshall
Keyword(s):  
Peninsular Malaysia ◽  
Tidal Range ◽  
Mangrove Creek ◽  
Nitrogen Concentrations

GIS-linked tidal range energy resource assessment

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Mirza Salman Baig ◽  
Zaheer Uddin ◽  
Ambreen Insaf
Keyword(s):  
Energy Resource ◽  
Resource Assessment ◽  
Tidal Range

Effects of marine pollution, climate, and tidal range on biomass and sediment organic carbon in Chinese mangrove forests

CATENA ◽  
2021 ◽  
Vol 202 ◽  
pp. 105270
Author(s):  
Gang Wang ◽  
Minerva Singh ◽  
Jiaqiu Wang ◽  
Ling Xiao ◽  
Dongsheng Guan
Keyword(s):  
Organic Carbon ◽  
Marine Pollution ◽  
Tidal Range ◽  
Mangrove Forests ◽  
Sediment Organic Carbon

scholarly journals Morphodynamic Evolution of a Nourished Beach with Artificial Sandbars: Field Observations and Numerical Modeling

2021 ◽  
Vol 9 (3) ◽  
pp. 245
Author(s):  
Cuiping Kuang ◽  
Xuejian Han ◽  
Jiabo Zhang ◽  
Qingping Zou ◽  
Boling Dong
Keyword(s):  
Sediment Transport ◽  
Tidal Current ◽  
Model Simulation ◽  
Morphological Changes ◽  
Current Model ◽  
Beach Nourishment ◽  
Tidal Range ◽  
Coastal Protection ◽  
Field Observations ◽  
One Year

Beach nourishment, a common practice to replenish an eroded beach face with filling sand, has become increasingly popular as an environmentally friendly soft engineering measure to tackle coastal erosion. In this study, three 200 m long offshore submerged sandbars were placed about 200 m from the shore in August 2017 for both coastal protection and beach nourishment at Shanhai Pass, Bohai Sea, northeastern China. A series of 21 beach profiles were collected from August 2017 to July 2018 to monitor the morphological changes of the nourished beach. Field observations of wave and tide levels were conducted for one year and tidal current for 25 h, respectively. To investigate the spatial-temporal responses of hydrodynamics, sediment transport, and morphology to the presence of three artificial submerged sandbars, a two-dimensional depth-averaged (2DH) multi-fraction sediment transport and morphological model were coupled with wave and current model and implemented over a spatially varying nested grid. The model results compare well with the field observations of hydrodynamics and morphological changes. The tidal range was around 1.0 m and the waves predominately came from the south-south-east (SSE) direction in the study area. The observed and predicted beach profiles indicate that the sandbars moved onshore and the morphology experienced drastic changes immediately after the introduction of sandbars and reached an equilibrium state in about one year. The morphological change was mainly driven by waves. Under the influences of the prevailing waves and the longshore drift toward the northeast, the coastline on the leeside of the sandbars advanced seaward by 35 m maximally while the rest adjacent coastline retreated severely by 44 m maximally within August 2017–July 2018. The model results demonstrate that the three sandbars have little effect on the tidal current but attenuate the incoming wave significantly. As a result, the medium-coarse sand of sandbars is transported onshore and the background silt is mainly transported offshore and partly in the longshore direction toward the northeast. The 2- and 5-year model simulation results further indicate that shoreline salient may form behind the sandbars and protrude offshore enough to reach the sandbars, similar to the tombolo behind the breakwater.

scholarly journals Optimising the Operation of Tidal Range Schemes

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2870 ◽  
Author(s):  
Jingjing Xue ◽  
Reza Ahmadian ◽  
Roger Falconer
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Maximum Energy ◽  
Energy Output ◽  
Tidal Range ◽  
Marine Renewable Energy ◽  
Modelling Methodology ◽  
Similar Operation ◽  
Swansea Bay ◽  
The Uk

Marine renewable energy, including tidal renewable energy, is one of the less exploited sources of energy that could contribute to energy demand, while reducing greenhouse gas emissions. Amongst several proposals to build tidal range structure (TRS), a tidal lagoon has been proposed for construction in Swansea Bay, in the South West of the UK, but this scheme was recently rejected by the UK government due to the high electricity costs. This decision makes the optimisation of such schemes more important for the future. This study proposes various novel approaches by breaking the operation into small components to optimise the operation of TRS using a widely used 0-D modelling methodology. The approach results in a minimum 10% increase in energy output, without the inclusion of pumping, in comparison to the maximum energy output using a similar operation for all tides. This increase in energy will be approximately 25% more when pumping is included. The optimised operation schemes are used to simulate the lagoon operation using a 2-D model and the differences between the results are highlighted.

scholarly journals Coastal Sensitivity/Vulnerability Characterization and Adaptation Strategies: A Review

2021 ◽  
Vol 9 (1) ◽  
pp. 72 ◽  
Author(s):  
Giorgio Anfuso ◽  
Matteo Postacchini ◽  
Diana Di Luccio ◽  
Guido Benassai
Keyword(s):  
Emergency Preparedness ◽  
Morphological Characteristics ◽  
Vulnerability Index ◽  
Tidal Range ◽  
Coastal Vulnerability ◽  
Natural Habitats ◽  
Factors Affecting ◽  
Cultural Aspects ◽  
Relevant Variables ◽  
Coastal Resilience

Coastal area constitutes a vulnerable environment and requires special attention to preserve ecosystems and human activities therein. To this aim, many studies have been devoted both in past and recent years to analyzing the main factors affecting coastal vulnerability and susceptibility. Among the most used approaches, the Coastal Vulnerability Index (CVI) accounts for all relevant variables that characterize the coastal environment dealing with: (i) forcing actions (waves, tidal range, sea-level rise, etc.), (ii) morphological characteristics (geomorphology, foreshore slope, dune features, etc.), (iii) socio-economic, ecological and cultural aspects (tourism activities, natural habitats, etc.). Each variable is evaluated at each portion of the investigated coast, and associated with a vulnerability level which usually ranges from 1 (very low vulnerability), to 5 (very high vulnerability). Following a susceptibility/vulnerability analysis of a coastal stretch, specific strategies must be chosen and implemented to favor coastal resilience and adaptation, spanning from hard solutions (e.g., groins, breakwaters, etc.) to soft solutions (e.g., beach and dune nourishment projects), to the relocation option and the establishment of accommodation strategies (e.g., emergency preparedness).

Influence of Intertidal Flats on Tidal Asymmetry

2005 ◽  
Vol 215 ◽  
pp. 1062-1067 ◽  
Author(s):  
André B. Fortunato ◽  
A. Oliveira
Keyword(s):  
Tidal Asymmetry ◽  
Intertidal Flats

scholarly journals Tidal asymmetry in an estuarine pycnocline: Depth and thickness

2000 ◽  
Vol 105 (C11) ◽  
pp. 26237-26251 ◽  
Author(s):  
Cynthia N. Cudaback ◽  
David A. Jay
Keyword(s):  
Tidal Asymmetry

scholarly journals GIS Based Approach for Vulnerability Assessment of the Karnataka Coast, India

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Akshaya Beluru Jana ◽  
Arkal Vittal Hegde
Keyword(s):  
Shoreline Change ◽  
Vulnerability Index ◽  
Tidal Range ◽  
Coastal Zones ◽  
Remotely Sensed Data ◽  
Coastal Vulnerability Index ◽  
Karnataka State ◽  
Administrative Units ◽  
2004 Tsunami ◽  
Very High

The coastal zones are highly resourceful and dynamic. In recent times, increased events of tropical cyclones and the devastating impact of the December 2004 tsunami have brought forth the importance of assessing the vulnerability of the coast to hazard-induced flooding and inundation in coastal areas. This study intends to develop coastal vulnerability index (CVI) for the administrative units, known astalukasof the Karnataka state. Seven physical and geologic risk variables characterizing the vulnerability of the coast, including rate of relative sea level change, historical shoreline change, coastal slope, coastal regional elevation, mean tidal range, and significant wave height derived using conventional and remotely sensed data, along with one socioeconomic parameter “population,” were used in the study. A total of 298 km of shoreline are ranked in the study. It was observed that about 68.65 km of the shoreline is under very high vulnerable category and 79.26 km of shoreline is under high vulnerable category. Of the remaining shoreline, 59.14 km and 91.04 km are of moderate and low vulnerable categories, respectively.

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