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Introduction to Estuarine Hydrodynamics

Langston Hughes

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Published in Introduction To Estuarine Hydrodynamics Arnoldo Valle Levinson

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Abstract

Estuarine hydrodynamics is a branch of fluid mechanics that deals with the flow of water in estuaries. Estuaries are dynamic environments where the mixing of fresh and salt water creates a unique set of physical, chemical, and biological conditions. Estuarine hydrodynamics is essential for understanding the transport and fate of pollutants, the design of coastal structures, and the management of estuarine ecosystems.

Introduction to Estuarine Hydrodynamics

by Arnoldo Valle-Levinson

5 out of 5

Language	:	English
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Print length	:	214 pages

Estuaries are coastal water bodies that are formed where rivers meet the ocean. They are characterized by a mix of fresh and salt water, and by strong tidal currents. Estuaries are important ecosystems that provide habitat for a variety of plants and animals, and they also play a role in the cycling of nutrients and the transport of sediment.

Estuarine hydrodynamics is the study of the flow of water in estuaries. It is a complex subject that involves the interaction of a number of different forces, including the tides, the wind, the Coriolis force, and the density difference between fresh and salt water.

Estuarine Circulation

The circulation of water in an estuary is driven by a number of forces, including the tides, the wind, and the Coriolis force. The tides are the most important force driving estuarine circulation. The rising and falling of the tide causes water to flow in and out of the estuary, creating a two-layer circulation pattern.

The upper layer of water in an estuary is typically fresh water, while the lower layer is salt water. The two layers are separated by a pycnocline, which is a zone of rapidly changing density. The pycnocline is formed by the mixing of fresh and salt water, and it is typically located near the mouth of the estuary.

The circulation of water in an estuary is influenced by a number of factors, including the geometry of the estuary, the tidal range, and the freshwater input. The geometry of the estuary affects the strength of the tidal currents and the location of the pycnocline. The tidal range affects the amount of water that flows in and out of the estuary, and the freshwater input affects the salinity of the water in the estuary.

Stratification

Estuaries are often stratified, meaning that the water is divided into two or more layers with different densities. The most common type of stratification in estuaries is haline stratification, which is caused by the difference in density between fresh and salt water. Haline stratification can be strong or weak, depending on the amount of freshwater input and the tidal range.

Strong haline stratification can lead to the formation of a salt wedge, which is a wedge of salt water that extends upstream into the estuary. Salt wedges can block the flow of freshwater into the estuary, and they can also create a barrier to the transport of sediment.

Mixing

Mixing is an important process in estuaries. It helps to break down the stratification and to create a more uniform environment. Mixing is caused by a number of factors, including the tides, the wind, and the Coriolis force.

The tides are the most important force driving mixing in estuaries. The rising and falling of the tide causes water to move back and forth across the pycnocline, breaking down the stratification. The wind can also cause mixing, particularly in shallow estuaries. The Coriolis force can also cause mixing, by creating a circulation pattern that helps to break down the stratification.

Sediment Transport

Sediment transport is an important process in estuaries. Sediment is transported into estuaries by rivers and by the tides. The amount of sediment that is transported into an estuary depends on a number of factors, including the size of the river, the tidal range, and the amount of sediment available.

Sediment is transported in estuaries by a variety of processes, including advection, diffusion, and resuspension. Advection is the transport of sediment by the flow of water. Diffusion is the transport of sediment by random molecular motion. Resuspension is the transport of sediment from the bottom of the estuary into the water column.

The transport of sediment in estuaries can have a number of impacts, including the formation of mudflats, the creation of sandbars, and the alteration of the channel morphology.

Estuarine hydrodynamics is a complex subject that is essential for understanding the transport and fate of pollutants, the design of coastal structures, and the management of estuarine ecosystems. This article has provided a brief overview of estuarine hydrodynamics, covering topics such as estuarine circulation, stratification, mixing, and sediment transport.

Introduction to Estuarine Hydrodynamics

by Arnoldo Valle-Levinson

5 out of 5