iCOAST: Integrated COASTal Sediment Systems

Lead Research Organisation: University of Manchester
Department Name: Mechanical Aerospace and Civil Eng

Abstract

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 the mesoscale (10-100 years and 10-100 km). However, their application has been limited to 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. All the software developed within iCoast will be open source and OpenMI compliant.
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.
Deliverable 2 will provide a new generation of behavioural geomorphic modules, which can be linked to enable simulation of coupled coastal-estuary-offshore landform behaviour at a meso-scale. Existing reduced complexity behavioural modules, several of which are held in-house within the iCoast consortium (SCAPE, ASMITA, various versions of 1-line beach models) will be reviewed and development and incremental improvement opportunities will be identified. They will be researched intensively by a team with unique experience of this type of model development. The scope of data-based modules that can exploit the growing datasets from coastal observatories will also be extended. The models will be integrated within a systems framework in order to study emergent properties and explore key sensitivities.
Deliverable 3 will entail application and validation of two distinct coastal regions: the Suffolk Coast (Sub-Cell 3c) and Liverpool Bay (Sub-Cells 11a/11b), exploring the sensitivities of these coastal regions to changes in sediment supply resulting from sea-level rise, climate change and coastal management scenarios. This 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.

Planned Impact

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, and hence 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 changing climate. Improved and evidence-based coastal management will also help to sustain coastal ecosystems, which are threatened by sea level rise and coastal squeeze and protected under the Habitats and Birds Directive.
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. The application of the tools from iCOAST will directly contribute to future revisions of the Environment Agency's Long-Term Investment Strategy and the UK Government's strategic goals with respect to the adaptation to, and mitigation of, climate change. It will also help with other needs such as the Water Framework Directive and other legislation.
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 iCoast project will contribute to the development of a range of research and professional skills in the research team and amongst the project stakeholders with whom we interact.
 
Description The iCOASST Project has demonstrated that improved decadal to centennial coastal geomorphic simulations are possible using new and improved models, both in isolation and in combination. This has been achieved by linking a range of components within a new conceptual framework. This framework comprises (1) qualitative understanding, most especially a new Coastal and Estuarine System Mapping (CESM) method, which formalise our understanding the geomorphic system components and their relationships and integrates open coast and estuary within a unifying framework; (2) coastal area models of the shallow seabed, which are used to qualify and quantify sediment fluxes and exchanges with the coast at broad spatial scales; (3) landform behavioural models to quantitatively predict coastal and estuarine morphological change over decadal to centennial timescales; and (4) model coupling at run time using OpenMI. CESM was developed and demonstrated within iCOASST and software developed that will allow this method to be applied by others. Existing coastal area models were developed and extended, and a range of numerical experiments were conducted for the iCOASST project. In terms of the landform behavioural models, iCOASST used existing models of the open coast (Unilinea) and estuaries (ASMITA), developed existing open coast models of shore platforms and finite beaches (SCAPE+), and produced completely new models of tidal inlets (MESO_i) and estuaries (ESTEEM).This gave a selection of models to link together into compositions and run together for demonstration sites from Sefton to Blackpool in NW England (using Unilinea and ASMITA) and the Deben Estuary and environs in Suffolk (using SCAPE+, MESO_i and ESTEEM).
Using the case studies and our new methods we have advocated and pursued a participatory modelling approach to the alignment of science and stakeholder perceptions of coastal morphological change. We held several meetings with stakeholders from each study site. In the earliest meetings we introduced the project and captured stakeholder perceptions of the management problems and issues affecting the part of the coast for which they are responsible. Insights gained from the stakeholders led to some changes in how we approached the problem, and we were able to feed these insights into our model development. By demonstrating our interest in their day-to-day management issues, and appreciation of their knowledge, we were able to achieve buy-in from stakeholders and have invaluable discussions on how results from the iCOASST project could contribute to practical, long-term coastal management in the UK.
The coupled model compositions both showed interesting results that would not have been apparent in stand-alone models. For example, if managed realignment (removal of coastal defences) along the Ribble Estuary (NW England) is too rapid this will create such a demand for sediment that impacts the adjoining open coast. Our model compositions thus allowed us to consider the wider coast in a holistic manner, and would allow coastal managers to determine unintended impacts of their management actions. In Suffolk (E England), it became apparent that there are small net littoral drifts on the open coast and that the Deben estuary inlet morphodynamics in particular mainly represents recycling of existing sediment. Coupling between the Deben estuary and the adjacent open coast is mainly via changes in the estuary tidal volume, which in turn influences the size of the inlet. We also experimented with tighter integration of multiple component models as an alternative to an external model coupling interface (OpenMI). To this end, a new Coastal ME platform has been developed to prototype stage and this integrates model approaches in a common data framework.
Exploitation Route This work is being taken forward in two ways. A dedicated web site on the Channel Coastal Observatory (http://www.channelcoast.org/) will archive all the results and the open source models for download. In addition, the Environment Agency are funding an additional piece of work over the next year to write a manual on the iCOASST methods and the wider issue of predicting decadal and centennial geomorphic evolution. There will also be a demonstration case study from the iCOASST models to a flood risk analysis which will show how these tools can inform strategic flood risk assessment. All Environment Agency results will be added to the CCO web site. Beyond these planned activities, the CESM approach could be applied to the entire coast of England and Wales and more widely as with small modifications, the approach is transferable globally. We have also been in discussion with owners of long-life infrastructure about applying the iCOASST methods to their frontages. The development of component iCOASST models (MESO_i, ESTEEM, SCAPE+) and the CoastalME platform will also continue beyond the life of the project.
Sectors Energy,Environment

 
Description The models, data and results are being publically archived on a web portal within the Channel Coastal Observatory (CCO) (http://www.channelcoast.org/). The CCO is the national repository for coastal data in England and is the main source of information for coastal engineering and management, including coastal morphodynamic data. Hence it is an effective dissemination partner. The CCO has been an embedded stakeholder from the beginning of the project. Information about iCOASST and the models will be made available on the iCOASST portal for download and use. In addition, input and output data files are in the process of being added, to allow users to identify the type and format of data required. This will allow new users to replicate the work of the iCOASST modellers. To further encourage effective dissemination, the models will be licenced under the General Public Licence, which promotes open access. The data files will be made available using the Open Government Licence. A preliminary web site will go live at Easter with updates to July 2016, and further updates planned beyond iCOASST based on EA-funded work. This dissemination route was planned from the beginning of the project and was included in our proposal. The Environment Agency (EA) are funding an additional set of work over the next year to further the uptake of iCOASST results. This was agreed at the beginning of the iCOASST Project and reflects that the EA were an embedded stakeholder throughout the life of the project. Importantly this commitment has been honoured despite the financial pressures within the EA. The outputs include an end-user manual on the iCOASST methods and the wider issue of predicting decadal and centennial geomorphic evolution of our coasts and estuaries. There will also be a demonstration case study linking the iCOASST models to a flood risk analysis which will show how these tools can inform strategic flood risk assessment. All these results will also be added to the CCO web site by 2017. Having the EA as an embedded stakeholder in the iCOASST project worked very well and this model is highly recommended to NERC and other research councils where appropriate.
First Year Of Impact 2015
Sector Environment
 
Description EPSRC IAA
Amount £60,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 04/2015 
End 03/2016