FIELD OBSERVATION AND MODELLING OF THE SEDIMENT TRIAD [FORMOST]
Lead Research Organisation:
Bangor University
Department Name: Sch of Ocean Sciences
Abstract
A strong team of experimentalists and modellers from the Proudman Oceanographic Laboratory (POL), Liverpool, and the University of Wales Bangor (UWB) aims to advance significantly our understanding, and hence representation, of coastal sediment transport processes. A three pronged attack is proposed, involving measurements, process formulations and area modelling, in order to probe the underlying physics in differing sediment transport regimes. Three complementary state-of-the-art data sets from the Deltaflume (large-scale laboratory) study, the LEACOAST2 project and the Dee Estuary, U.K., will be employed. These data, obtained using innovative optical and acoustic techniques, are starting to provide the breakthrough in our understanding of near-bed transport processes that will be employed to develop the next generation of advanced models. Here the focus will be on the improvement of the established UWB Sand Transport Model that has been under development for the past 15 years. This will be achieved through the use of existing field data from both the sandy LEACOST2 site (at Sea Palling, U.K.) and the complex, mixed sediment environment of the outer Dee Estuary, supplemented by new field experiments in the outer Dee. This new data will be used to advance, and fully integrate, the modelling of sediment transport processes on local scales into models on larger coastal area scales, helping to address the surprisingly large gap that has arisen regarding the transfer of process-based knowledge into the developing coastal modelling systems. The project will exploit new observational capabilities in the field, particularly through the use of a Coherent Doppler Velocity Profiler (CDVP) that will allow detailed near-bed velocity profiles to be measured in the field, in order to improve and validate local sediment transport models in conditions involving steep waves combined with currents over seabeds comprising mixed sediment sizes. The CDVP will complement our existing state-of-the-art capabilities in the acoustic measurement of both sediment in suspension and also bed form geometry. The results from the improved local models will be validated using both the prototype laboratory data and existing/new field data. The resulting models will be run over extensive wave, current and (mixed) sediment size ranges of practical importance, and the model results will be parameterised for use in coastal area modelling systems. Since the computer run times of such modelling systems can still be prohibitively long, consideration will be given to model 'input filtering', particularly in relation to the schematisation of an (annual) climate of waves combined with a Spring-Neap variation in the tidal forcing. The new sediment transport formulations will be implemented in two coastal area modelling systems, namely the POLCOMS (POL Coastal Ocean Modelling System), and the TELEMAC Modelling System, which are in use and under development at both POL and UWB. Both POLCOMS and TELEMAC will be used to compute the annual sediment transport budget in a modelled area defined in the outer channels of the Dee Estuary, a site that exemplifies many of the coastal and estuarine problems around the UK coastline that are likely to be exacerbated by future sea-level rise and increased storminess. This exercise will help to address generic questions such as: Does accretion of sediment occur within an estuary from offshore sediment sources?; and, are wave effects a critical factor in determining whether an estuary accretes or erodes? The underlying rationale for the modelling on both small process scales and larger coastal area scales is to determine the extent to which our predictive capabilities related to sand transport remain valid in a sand-dominated but mixed (i.e. with a small fine fraction) sediment environment.
Organisations
Publications
Hurther D
(2011)
A multi-frequency Acoustic Concentration and Velocity Profiler (ACVP) for boundary layer measurements of fine-scale flow and sediment transport processes
in Coastal Engineering
Thorne PD
(2008)
A review of the scattering properties of suspended sandy sediments for the application of acoustics to sediment transport studies
in Proceedings of the 9th European conference on underwater acoustics ECUA 2008,
Malarkey J
(2012)
A simple procedure for calculating the mean and maximum bed stress under wave and current conditions for rough turbulent flow based on method
in Computers & Geosciences
Thorne PD
(2011)
Acoustic inversions for measuring boundary layer suspended sediment processes.
in The Journal of the Acoustical Society of America
Thorne PD
(2009)
Acoustical observations of velocity and suspended sediment structures due to oscillatory flow over a rippled bed
in Proceedings of the 6th International Conference on Coastal Dynamics, Tokyo, 7-11 Sep
Brown J
(2010)
An 11-year validation of wave-surge modelling in the Irish Sea, using a nested POLCOMS-WAM modelling system
in Ocean Modelling
Simons R
(2011)
Briefing: Young Coastal Scientists and Engineers Conference 2010
in Proceedings of the Institution of Civil Engineers - Maritime Engineering
Betteridge K
(2008)
Calibrating multi-frequency acoustic backscatter systems for studying near-bed suspended sediment transport processes
in Continental Shelf Research
Bolaños R
(2012)
Comparison of measurements and models of bed stress, bedforms and suspended sediments under combined currents and waves
in Coastal Engineering
Brown J
(2014)
Controls on monthly estuarine residuals: Eulerian circulation and elevation
in Ocean Dynamics
Amoudry L
(2011)
CORRIGENDUM
in Journal of Atmospheric and Oceanic Technology
Wolf J
(2010)
Coupled wave-current modelling and validation in Liverpool Bay
in Waves In Shallow water Environment (WISE) meeting, Brest, 25-29 Apr,
Amoudry L
(2011)
DETERMINISTIC COASTAL MORPHOLOGICAL AND SEDIMENT TRANSPORT MODELING: A REVIEW AND DISCUSSION
in Reviews of Geophysics
Souza AJ
(2010)
Effects of asymmetric strained stratification on currents, turbulence and sediment transport
in Ocean Sciences 2010, Portland USA, 22-26 Feb,
Souza A
(2008)
Effects of tidal straining on the semidiurnal cycle of dissipation in the Rhine region of freshwater influence: Comparison of model and measurements
in Journal of Geophysical Research: Oceans
Brown J
(2012)
Extracting sea level residual in tidally dominated estuarine environments
in Ocean Dynamics
Brown J
(2010)
Flood/ebb tidal asymmetry in a shallow sandy estuary and the impact on net sand transport
in Geomorphology
Thorne P
(2008)
Formulations for the scattering properties of suspended sandy sediments for use in the application of acoustics to sediment transport processes
in Continental Shelf Research
Malarkey J
(2012)
Free-stream velocity descriptions under waves with skewness and asymmetry
in Coastal Engineering
Moore Rowena Deborah
(2009)
Hydrodynamic and Morphometric Modelling of a Macro-Tidal Estuary : The Dee Estuary of NW England
Brown J
(2011)
Impact assessment of advanced coupling features in a tide-surge-wave model, POLCOMS-WAM, in a shallow water application
in Journal of Marine Systems
Amoudry L
(2011)
Impact of sediment-induced stratification and turbulence closures on sediment transport and morphological modelling
in Continental Shelf Research
Amoudry LO
(2010)
Influence of turbulence closure on estuarine sediment dynamics and morphodynamics
in Proceedings of the 32nd International Conference on Coastal Engineering (ICCE), Shanghai, 30 Jun - 5 Jul
Moate B
(2012)
Interpreting acoustic backscatter from suspended sediments of different and mixed mineralogical composition
in Continental Shelf Research
O'Hara Murray R
(2011)
Intrawave observations of sediment entrainment processes above sand ripples under irregular waves
in Journal of Geophysical Research
Pan S
(2010)
Larger-scale Morphodynamic Impacts of Segmented Shore-Parallel Breakwaters on Coasts and Beaches: An Overview of the LEACOAST2 Project
in Shore and Beach (Journal of ASBPA)
Moate BD
(2009)
Measurements and inversion of acoustic scattering from suspensions having broad size distributions.
in The Journal of the Acoustical Society of America
Bolaños R
(2010)
Measuring hydrodynamics and sediment transport processes in the Dee Estuary
in Earth System Science Data
Thorne PD
(2010)
Measuring marine boundary layer suspended sediment processes using sound
in Proceedings of the 10th European Conference on Underwater Acoustics, Istanbul, Jul 5-9
Bolaños R
(2009)
Measuring suspended sediment and its wave and turbulence forcing in the Dee Estuary
in Proceedings of the 6th International Conference on Coastal Dynamics, Tokyo, 7-11 Sep
Bolaños R
(2009)
Measuring tidal hydrodynamics and bedform evolution in the Dee Estuary
in Proceedings of the 6th IAHR Symposium on River, Coastal and Estuarine Morphodynamics (RCEM 2009), Santa Fe, Argentina, 21-25 Sep
Chini N
(2010)
Modelling long term implication of climate change projection on shore morphology of North Norfolk, UK, combining TOMAWAC and SCAPE
in Proceedings of the 32nd International Conference on Coastal Engineering (ICCE), Shanghai, 30 Jun - 5 Jul
Moore R
(2009)
Morphological evolution of the Dee Estuary, Eastern Irish Sea, UK: A tidal asymmetry approach
in Geomorphology
Thorne P
(2009)
Observations and analysis of sediment diffusivity profiles over sandy rippled beds under waves
in Journal of Geophysical Research: Oceans
Thorne PD
(2010)
On Applying acoustics in mixed sediment environments
in Particles in Europe (PiE) Conference, Villefranche-sur-Mer, 14-17 Nov,
Amoudry L
(2010)
Parameterization of near-bed processes under collinear wave and current flows from a two-phase sheet flow model
in Continental Shelf Research
Amoudry LO
(2009)
Sediment Transport Module for a B-Grid Coastal Shelf Ocean Model
in Proceedings of the 6th International Conference on Coastal Dynamics, Tokyo, 7-11 Sep
Hurther D
(2011)
Suspension and near-bed load sediment transport processes above a migrating, sand-rippled bed under shoaling waves
in Journal of Geophysical Research: Oceans
Chini N
(2010)
The impact of sea level rise and climate change on inshore wave climate: A case study for East Anglia (UK)
in Coastal Engineering
Wolf J
(2011)
The wave climate of Liverpool Bay-observations and modelling
in Ocean Dynamics
Bolaños R
(2011)
Three dimensional circulation modelling in the Dee Estuary
in Journal of Coastal Research
Souza A
(2013)
Tidal, Riverine, and Wind Influences on the Circulation of a Macrotidal Estuary
in Journal of Physical Oceanography
Bolaños R
(2010)
Time and Spatial Distribution of Sediment in Suspension in the Dee Estuary
in Physics of Estuaries and Coastal Seas (PECS), Colombo Sri Lanka
Cacchione D
(2008)
Time-averaged near-bed suspended sediment concentrations under waves and currents: Comparison of measured and model estimates
in Continental Shelf Research
Thurston William
(2009)
Turbulence as a mediator of processes in a macrotidal estuary
Amoudry LO
(2010)
Upscaling of sediment erosion parameterization from small-scale, intra-wave models to regional scale ocean models
in Ocean Sciences 2010, Portland USA, 22-26 Feb,