Sediment transport

Sediment transport simulations examine the movement of solid particles within a liquid or gas. This can include transport within the natural or built environments, for example coastal, marine, fluvial or aeolian transport, or transport within a chemical or water treatment plant.

For queries about this topic, contact Joanna Nield.

View the calendar of events relating to this topic.

Projects

Feasibility Study of the Impacts of Proposed Tidal Array Installations in Channel Islands

Luke Blunden (Investigator), William Batten

Open source hydrodynamic modelling software TELEMAC is being used to see whether putting a large number of tidal turbines in the sea near a headland-associated sandbank will affect the feature's long term equilibrium.

Flow and sedimentation processes in submarine meandering channels

Stephen Darby (Investigator)

The overall aim of this project is to generate a step-change in our understanding of the interactions between flow,
morphology & sedimentology within an active submarine channel fed by saline density currents. This central aim will be addressed through a combination of field measurements and innovative numerical modelling of gravity current morphodynamics

Impacts of Climate and Sea-Level Change on Coastal Gullies

Stephen Darby (Investigator), Chris Hackney, Julian Leyland

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Modelling Macro-Nutrient Release & Fate Resulting from Sediment Resuspension in Shelf Seas

Chris Wood

This study involves adapting a previously-published model to take into account the effect resuspension events (both natural and anthropogenic) may have on nutrient dynamics at the sediment-water interface, and hence produce better estimates for the total nutrient budgets for shelf seas.

Modelling the morphodynamic evolution of the Ganges-Brahmaputra-Meghna (GBM) Delta over centennial time scales

Stephen Darby (Investigator), Balaji Angamuthu

Around 0.5 Billion people live in deltaic environments where they are threatened by flooding and land loss frequently. Yet, our understanding of the threats posed by land dynamic process remains limited. In this work, we try to address this issue through a land dynamic simulation of the largest and most populated of all the deltas, the GBM Delta, using the CFD software Delft3D for a range of climate change and management scenarios. The results provide new insight into the factors controlling past morphodynamics that, in turn, are helpful when assessing the possible trajectories of future evolution.

Multidecadal Sediment Fluxes to Deltas Under future Environmental Change Scenarios

Stephen Darby (Investigator), Frances Dunn

Coastal deltas, on which over half a billion people live worldwide, maintain elevation above sea level by retaining sediment on their surfaces. The aim of this research is to project future fluvial sediment delivery to 47 deltas under environmental change scenarios to assess the sustainability of deltas environments globally.

Sediment Transfer and Erosion on Large Alluvial Rivers (STELAR-S2S)

Stephen Darby, Julian Leyland, Christopher Hackney (Investigators)

STELAR-S2S will provide the first comprehensive quantification of autogenic and climatic controls on riverine sediment fluxes for one of the world's largest rivers (the Mekong), leading to new generic understanding of the relationships between climatic variability, fluvial processes and sediment flux to deltaic zones and the ocean.

Surface moisture-induced feedback in aeolian environments

Joanna Nield (Investigator)

This project explores the importance of surface moisture for aeolian processes, particularly feedback between surface moisture and bedform sedimentation and migration.

The Origin of Aeolian Dunes (TOAD)

Joanna Nield (Investigator)

The overall aim of this project is to understand the genesis and subsequent evolution of aeolian early stage bedforms by quantifying for the very first time the role and importance of flow, transport and surface feedbacks in the initiation and emergence of dunes. This project offers the genuine prospect of surmounting arguably the major enduring research question within aeolian geomorphology, leading to broader insights which will offer knowledge benefits for sedimentary landform studies as a whole.

The Role of the Biota in the Carpenter Model on Lake Eutrophication

James Dyke (Investigator), Alexandra Diem

The Carpenter model is a useful and simple model to predict the eutrophication of shallow lakes via phosphorus input. This project aimed at resolving the function of the biota, which play a major role in the phosphorus dynamics, but are so far only implicitly modelled, and extending the model to explicitly represent them.

Vertical turbulence structures in the benthic boundary layer as related to suspended sediments

Hachem Kassem (Investigator), Charlie Thompson

There is a genuine need for better, more robust modelling of suspended sediment transport in the coastal zone, both to understand its morphological evolution and it's impact on biogeochemical cycling, ecosystems services and to guide engineering applications such as dredging and defence schemes against erosion and flooding.
The suspension of sediment in turbulent flows is a complex case of fluid-particle interaction, governed by shear stresses (momentum exchanges) at the bed and within the benthic boundary layer (BBL). The intermittent transfer of momentum is a manifestation of coherent turbulent vortex structures within the flow. The passage of such structures (or clusters of) is often related to perturbations of bottom sediment, which may be entrained and maintained in suspension if sufficient turbulent energy is provided. The first part of my PhD investigated the temporal and scale relationships between wave–generated boundary layer turbulence and event–driven sediment transport in oscillatory flow in the nearshore. This involved complex statistical, spectral, quadrant and wavelet analysis of high frequency nearshore measurements of turbulence and suspended sediments (medium sand), collected as part of the EU-funded Barrier Dynamics Experiment II (BARDEX II). The following step aims to develop a 3D numerical model in OpenFOAM which would reproduce the fine scale turbulence structures observed over a fixed rippled bed in oscillatory flow. The 3D velocity field, turbulent components, correlations (stresses) and quadrant structures will then be linked to observed sediment resuspension events. The model will be validated against a set of laboratory experiments undertaken at the Fast Flow Facility at HR Wallingford.