iCOAST: Integrated COASTal sediment systems

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.

The beneficiaries from the research fall into two main categories:

1. The worldwide coastal research community, who recognise the difficult problem of mesoscale coastal prediction, will be eager to take up new methodologies. This is evidenced by the rapid uptake of the SCAPE model, which has now been applied in New Zealand and the Great Lakes as well as at several sites in the UK.

2. Coastal practitioners in the UK and worldwide, urgently need new mesoscale predictions of coastal change in order to manage the risks of coastal erosion and coastal flooding. These coastal risks are profoundly influenced by the long term behaviour of coastal sediment systems, but existing predictive approaches are severely limited, especially in conditions of long term change. Coastal practitioners include those in government and its agencies (e.g. the Environment Agency) and those in local authorities with responsibility for coastal management and adaptation. Whilst the focus of the research is upon UK coasts, the leading UK coastal consultants (e.g. Halcrow, HR Wallingford, Royal Haskoning) have considerable international businesses, so the UK is expected to benefit through the exploitation of iCoast science by these organisations in their international businesses.

Ultimately, coastal communities will benefit from more sustainable coastal management that is based upon dependable predictions of coastal change. This will help to reduce the risks from flooding and coastal erosion and help to ensure that the costs of coastal management do not become unmanageable in future, even in the context of a changed climate. Improved and evidence-based coastal management will also help to sustain coastal ecosystems, which are threatened by sea level rise and coastal squeeze.

The benefits from the research will derive from the developed methods for enhancing understanding and predicting processes of coastal change. Enhanced understanding will be delivered in particular via the new tools for systems mapping, which have already proved to be a worthwhile approach to formalising knowledge of coastal processes but which will be considerably extended in the course of the iCoast research. The process of developing behavioural geomorphic models will yield new insights into the controls upon coastal change and the ways in which coasts may be modified by changed environmental forcings. The coastal area modelling will yield new insights into the complex processes of sea bed sediment transport.
Of most practical benefit will be the new predictive tools that are developed in the iCoast project. These will take a number of different forms, including coastal area models, data-based methods and behavioural geomorphic models. They will all be developed with a focus upon predicting the variables of most relevance to coastal managers, along with well justified uncertainty estimates.

There is a realistic prospect that innovations in the iCoast project will be rapidly taken up in practice. There is an urgent need for better predictive models to analyse coastal risks and justify coastal adaptation strategies. Strong links with the practitioner community and well developed knowledge transfer mechanisms mean that outputs can be transferred into practice as soon as they are demonstrated and validated. These innovations need not wait till the end of the project to be taken up in practice.

The cohort of researchers employed in the iCoast project will develop scarce skills and systems perspectives which are in short supply in both the research and practitioner communities. Thus the iCoast project will contribute to the development of these research and professional skills in the research team and amongst the project stakeholders with whom we interact.