麻豆网

Overview

This module provides an introduction to the dynamics of entrainment, transport and deposition of non-cohesive and cohesive sediments in the ocean. The topics covered include:

• physical mechanisms of sediment transport, and physico-chemical controls of sedimentation;
• tidal and wave boundary layers;
• initiation of motion and Shields criterion;
• sediment transport in steady and oscillatory flows;
• the entrainment of sediments into suspension;
• bed forms in steady and oscillatory flow;
• geotechnical and hydraulic interpretation of sediment textures and structures;
• origin and nature of bed forms, ripples, dunes, bars;
• density currents and avalanches: low density turbidity currents versus avalanches.

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You will spend time in the laboratory observing and measuring sediment transport, and in weekly workshop sessions exploring practical approaches to quantifying the movement of sediments in the marine environment. Significant effort is spent on developing skills for future graduate employment.

This course provides an introduction to the dynamics of entrainment, transport and deposition of non-cohesive and cohesive sediments in coastal waters. The topics covered include:

• physical mechanisms of sediment transport, and physico-chemical controls of sedimentation;
• tidal and wave boundary layers;
• sediment transport in steady and oscillatory flows;
• initiation of motion and shields criterion;
• bed load motion;
• sediment entrainment and suspension;
• bed forms in steady and oscillatory flow;
• measurement and estimation of sediment transport rates;
• geotechnical and hydraulic interpretation of sediments textures and structures;
• origin and nature of bed forms, ripples, dunes, bars;
• density currents and avalanches: low density turbidity currents versus avalanches.

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You will spend time in the laboratory observing and measuring sediment transport, and learning the basic principles and methods of sampling sediment in the marine environment.

Assessment Strategy

Threshold - (D minus grade) Basic understanding of knowledge (subject-specific theories, concepts and principles) of the processes of sediment dynamics based on the directly taught programme;Basic ability to define and solve numerical problems using appropriate techniques, and to interpret the results.

Good - (B grade) Good understanding of knowledge (subject-specific theories, concepts and principles) of the processes of sediment dynamics based on the directly taught programme;Good ability to define and solve numerical problems using appropriate techniques, and to interpret the results.

Excellent - (A grade) Thorough understanding of knowledge (subject-specific theories, concepts and principles) of the processes of sediment dynamics based on the directly taught programme;Thorough ability to define and solve numerical problems using appropriate techniques, and to interpret the results.

Learning Outcomes

• Be able to quantifiably describe the formation and evolution of sedimentary bedform features, and understand their contribution to wider sediment transport and seabed dynamics.

• Be able to use Matlab or similar software to manipulate and analyse numerical datasets and develop tools to provide quantitative answers to complex problems

• Draw quantitative conclusions about sediment transport based on the analysis of given field or numerical model data sets

• Have demonstrable knowledge of the physical, chemical and biological factors that control cohesion and flocculation processes.

• Understand the concepts of sediment entrainment leading to bed load sediment transport and the progression to sediment suspension due to the balance of turbulent upthrust and sediment settling.

• Understand the fluid-seabed interactions that generate the benthic boundary layer, the subsequent form of the boundary layer and the resultant bed shear stresses under steady and oscillatory flows.