A4 - Long-term sediment transport measurement and modelling

A - Resource and Environment Characterisation

Status - published
Last updated on: 21/03/2022

Challenges/Opportunities

Ocean sediments can be mobile, affecting offshore structures, cables and habitat. The motion of sands and other sediments and the possibility of scour must be predicted, as well as environmental harm minimised.

Solution

Reliable multiscale methods - which work at region and farm scale, as well as local to structures - are needed to predict changes in bathymetry, sediments and habitat, validated by field surveys.

Context And Need

The mobility of the seabed through sediment transport can affect offshore renewable energy (ORE) facilities. Scour management is often required around seabed structures and sediment transport can also affect cable integrity. In shallow estuaries, the change in flow from tidal energy facilities can create sediment morphological change. These sediment transport phenomena can affect the function of ORE systems and can also impact on habitat and ecosystems. A better understanding of these processes, through accurate models validated by field observations, will help to ensure that sediment transport processes associated with ORE systems do not cause adverse effects to those systems or the environment.

Summary

Morphological change in tidal races, tidal estuaries and the open ocean is not well understood, hampering exploitation resources. If the changes to water flow, sediment and habitat can be predicted, confidence in design and social acceptability will be raised.

Impact Potential

Habitat directive is currently an effective barrier to EIA consenting in estuaries. Unlocking significant resource and consequent social and environmental benefits.

Benthic change management and augmentation.

Reducing wind farm asset OPEX through reduced sediment related cable damage.

(social) Tourism risk due to lagoons changes from Sandy to Muddy beaches quantified.

Access/use of estuaries for other purposes (economic/social).

Other potential areas of interest: climate change, civil engineering, coastal protection

Research Status

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Supergen ORE Hub Flexible Funding Research

  • Cable scour from fluid-seabed interactions in regions of mobile sedimentary bedforms
    Lead Institution: Bangor University

    Growing demand for renewable forms of energy extraction highlights the essential role of subsea power cables. In 2018, UK’s operational offshore wind farms were using 1,499 km of export and >1,806 km of inter-array cables to transport 6,385 MW of electrical power. 43 array and export cable failures have been reported between 2007 and 2018, resulting from a number of reasons including sediment and sedimentary bedform mobility and accidents from e.g. dredging and benthic fishing. This proposal is the first to make detailed field measurements of scour development over a section of real subsea cable. Existing assessments of cable scour from state-of-the-art labs and numerical models have provided valuable insight but are inherently limited. This project aims to provide a validated benchmark scenario linking turbulent flow and scour development relevant to ORE subsea cables at local to centimetric scales. To allow industry to apply new knowledge in the development of upscaled lab experiments and numerical models to provide optimised methods for cable protection, particularly where array-scale effects may feedback to and modify seabed mobility over larger areas than expected.

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Links to Industry Priorities:

Offshore-Wind-Innovation-Hub-Roadmap-Data-Seabed-structure-interaction-and-fluid-structure-interaction

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We would also like to invite UK researchers and industry stakeholders within ORE to submit links to research projects, both past and present, for inclusion within the landscape.

Therefore, if you have a UK-based research project within an area of ORE that you feel is relevant to a specific research theme or challenge within the Research Landscape, click HERE to submit your research project to the research landscape

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PhD projects in Offshore Renewable Energy

In order to better understand the breadth of ORE research currently being conducted in the UK, the Supergen ORE Hub has collated from its academic network, UK Centres for Doctoral Training and Industrial partners, a list of PhDs currently being undertaken in ORE.

Access a PDF of the list and find out more about including your PhD.

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