Tidal currents and wind waves controlling sediment distribution in a subtidal point bar of the Venice Lagoon (Italy)

Sedimentology ◽  
2019 ◽  
Vol 66 (7) ◽  
pp. 2926-2949 ◽  
Author(s):  
Massimiliano Ghinassi ◽  
Andrea D'Alpaos ◽  
Laura Tommasini ◽  
Lara Brivio ◽  
Alvise Finotello ◽  
...  
Keyword(s):  
Wind Waves ◽  
Venice Lagoon ◽  
Tidal Currents ◽  
Point Bar ◽  
Sediment Distribution

scholarly journals Tidal Currents versus Wind Waves

Nature ◽  
1881 ◽  
Vol 24 (620) ◽  
pp. 460-460
Author(s):  
G. H. KINAHAN
Keyword(s):  
Wind Waves ◽  
Tidal Currents

Effects of tidal currents on winter wind waves in the Qiongzhou Strait: a numerical study

2020 ◽  
Vol 39 (11) ◽  
pp. 33-43
Author(s):  
Peng Bai ◽  
Zheng Ling ◽  
Cong Liu ◽  
Junshan Wu ◽  
Lingling Xie
Keyword(s):  
Numerical Study ◽  
Wind Waves ◽  
Tidal Currents ◽  
Qiongzhou Strait

scholarly journals MODELLING WAVE-TIDE INTERACTIONS AT A WAVE FARM

2011 ◽  
Vol 1 (32) ◽  
pp. 34 ◽  
Author(s):  
Raul Gonzalez-Santamaria ◽  
Qingping Zou ◽  
Shunqi Pan ◽  
Roberto Padilla-Hernandez
Keyword(s):  
Sediment Transport ◽  
Wind Waves ◽  
Tidal Currents ◽  
Bottom Friction ◽  
Main Question ◽  
Tidal Elevation ◽  
Coastal Morphology ◽  
Energy Devices ◽  
Wave Farm ◽  
Modelling System

The Wave Hub project will create the world’s largest wave farm off the coast of Cornwall, Southwest England. This study is to investigate wave and tide interactions, in particular their effects on bottom friction and sediment transport at the wave-farm coast. This is an ambitious project research which includes the use of a very complex numerical modelling system. The main question to answer is how waves, tidal currents and winds affect the bottom friction at the Wave Hub site and the near-shore zone, as well as their impact on the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height predictions, tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport, waves via radiation stresses have an important effect on the long-shore and cross-shore velocity components, particularly during the spring tides, waves can impact on bottom boundary layer and the mixing in the water column. Interactions between waves and tides at the Wave Hub site is important when modelling coastal morphology influenced by wave energy devices, this open-source modelling system tool will help the study of physical impacts on the Wave Hub farm area.

scholarly journals Detecting the Delayed Signatures of Changing Sediment Supply in Salt-Marsh Landscapes: The Case of the Venice Lagoon (Italy)

2021 ◽  
Vol 8 ◽  
Author(s):  
Marcella Roner ◽  
Massimiliano Ghinassi ◽  
Alvise Finotello ◽  
Adele Bertini ◽  
Nathalie Combourieu-Nebout ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Wind Waves ◽  
Time Lag ◽  
Vertical Plane ◽  
Deep Understanding ◽  
Venice Lagoon ◽  
Sediment Supply ◽  
Sediment Input ◽  
Lateral Erosion ◽  
Salt Marsh Sediments

Many salt-marsh systems worldwide are currently threatened by drowning and lateral erosion that are not counteracted by sufficient sediment supply. Here we analyze the response of a salt-marsh system to changes in sediment availability and show that, contrary to what would have been expected, marsh dynamics in the vertical plane can be insensitive to large sediment supply. We integrate sedimentological, geochronological, paleoecological, geophysical, and chemical analyses of salt-marsh sediments accumulated over the past six centuries in the Southern Venice Lagoon (Italy), and suggest that a time lag exists between enhanced river-fed clastic sediment input and its signature in the salt-marsh succession. This time lag is likely caused by the stocking of the sediment along the margins of pre-existing marshes, which started to significantly expand horizontally – rather than accrete vertically – when sediment input increased. When sediment input drastically decreased, wind waves re-suspended the river-fed deposits and distributed them over the marsh platform, eventually allowing for vertical accretion. Understanding the response of salt-marsh systems to changes in sediment supply has important implications for the management of tidal landscapes and the prediction of their evolution under the effects of natural and anthropogenic forcings. Our results highlight that the study of ultra-recent sedimentary successions needs to be carried out on the basis of a deep understanding of specific depositional dynamics.

scholarly journals Identifying Hydro-Geomorphological Conditions for State Shifts from Bare Tidal Flats to Vegetated Tidal Marshes

2020 ◽  
Vol 12 (14) ◽  
pp. 2316
Author(s):  
Chen Wang ◽  
Sven Smolders ◽  
David P. Callaghan ◽  
Jim van Belzen ◽  
Tjeerd J. Bouma ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Wind Waves ◽  
High Elevation ◽  
Scientific Basis ◽  
Tidal Currents ◽  
Aerial Images ◽  
Tidal Marshes ◽  
Stable States ◽  
Vegetation Growth ◽  
Vegetation Biomass

High-lying vegetated marshes and low-lying bare mudflats have been suggested to be two stable states in intertidal ecosystems. Being able to identify the conditions enabling the shifts between these two stable states is of great importance for ecosystem management in general and the restoration of tidal marsh ecosystems in particular. However, the number of studies investigating the conditions for state shifts from bare mudflats to vegetated marshes remains relatively low. We developed a GIS approach to identify the locations of expected shifts from bare intertidal flats to vegetated marshes along a large estuary (Western Scheldt estuary, SW Netherlands), by analyzing the interactions between spatial patterns of vegetation biomass, elevation, tidal currents, and wind waves. We analyzed false-color aerial images for locating marshes, LIDAR-based digital elevation models, and spatial model simulations of tidal currents and wind waves at the whole estuary scale (~326 km²). Our results demonstrate that: (1) Bimodality in vegetation biomass and intertidal elevation co-occur; (2) the tidal currents and wind waves change abruptly at the transitions between the low-elevation bare state and high-elevation vegetated state. These findings suggest that biogeomorphic feedback between vegetation growth, currents, waves, and sediment dynamics causes the state shifts from bare mudflats to vegetated marshes. Our findings are translated into a GIS approach (logistic regression) to identify the locations of shifts from bare to vegetated states during the studied period based on spatial patterns of elevation, current, and wave orbital velocities. This GIS approach can provide a scientific basis for the management and restoration of tidal marshes.

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