iCOAST: Integrated COASTal sediment systems

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Prediction of changing coastal morphology over timescales of decades raises scientific challenges to which there are not yet widely applicable solutions. Yet improved predictions are essential in order to quantify the risk of coastal erosion, which is significant in its own right and also one of the main mediators of coastal flood risk. Whilst 'bottom-up' process-based models provide valuable evidence about hydrodynamic, sediment transport and morphodynamic processes in the short term, their predictive accuracy over scales of decades is for the time being fundamentally limited. Meanwhile, behavioural systems models, that focus on the main processes and feedback mechanisms that regulate coastal form have been shown to have predictive capability at a mesoscale (10-100y and 10s-100km) but so far only in a rather narrow sub-set of coastal forms.The iCoast project is based upon a hierarchical systems concept which combines (i) the beneficial features of process-based models, (ii) a new generation of coastal behavioural systems models and (iii) an extended approach to coastal systems mapping, which can be used to systematise and formalise different sources of knowledge about coastal behaviour.The research is focussed upon four deliverables that have been identified as major challenges in the NERC Natural Hazards Theme:Deliverable 1 will be an overall systems framework. The successful approach to coastal systems mapping developed by French et al. will be extended and applied to all of the England and Wales, making use of a new systems mapping tool. These new coastal systems maps can both supersede the coastal cells and sub-cells currently used in shoreline management planning and provide an evidence-based framework for more quantitative modelling. Therein, hydrodynamic and sediment transport coastal area models will be implemented at a broad spatial scale in order to provide evidence of wave and tidal forcings and sediment pathways. The systems framework will be implemented in open source software tools and coupled with methods for uncertainty analysis. Coupling with proprietary tools will, where appropriate, be implemented in OpenMI.Deliverable 2 will be a new generation of reduced complexity behavioural geomorphic models to enable simulation of coupled coastal-estuary-offshore landform behaviour at a meso-scale. Work on this deliverable will begin by reviewing existing behavioural modules, several of which are held in-house within the iCoast consortium (SCAPE, ASMITA, various version of 1-line beach models). Identified priorities for new development and incremental improvement will be researched intensively by a team with unique experience of this type of model development. The scope of data-based models that can exploit the rapidly expanding datasets from coastal observatories will be extended. The models will be integrated within a systems framework in order to identify emergent properties and explore key sensitivities.Deliverable 3 will entail application and validation at two coastal regions, namely the Suffolk Coast (Sub-Cell 3c) and Liverpool Bay (Sub-Cells 11a and 11b), exploring the sensitivities of these coastal regions to changes in sediment supply resulting from sea-level rise, climate change and coastal management scenarios. These applications will yield the results needed for high impact publication and the demonstrations that are essential to build confidence in new approaches being transferred into practice.Deliverable 4 will facilitate knowledge transfer of the new methods through a range of dissemination mechanisms, including tutorials, manuals and knowledge transfer workshops. Our open source modelling strategy will initiate a community modelling approach in the coastal research community, at the same time as maximising access by practitioners to the knowledge generated at a time when requirements for coastal adaptation urgently require new predictive capability.