Characterisation and prediction of large-scale, long-term change of coastal geomorphological behaviours: Final science report Science Report: SC060074/SR1 Product code: SCHO0809BQVL-E-P The Environment Agency is the leading public body protecting and improving the environment in England and Wales. It’s our job to make sure that air, land and water are looked after by everyone in today’s society, so that tomorrow’s generations inherit a cleaner, healthier world. Our work includes tackling flooding and pollution incidents, reducing industry’s impacts on the environment, cleaning up rivers, coastal waters and contaminated land, and improving wildlife habitats. This report is the result of research commissioned by the Environment Agency’s Science Department and funded by the joint Environment Agency/Defra Flood and Coastal Erosion Risk Management Research and Development Programme. Published by: Author(s): Environment Agency, Rio House, Waterside Drive, Richard Whitehouse, Peter Balson, Noel Beech, Alan Aztec West, Almondsbury, Bristol, BS32 4UD Brampton, Simon Blott, Helene Burningham, Nick Tel: 01454 624400 Fax: 01454 624409 Cooper, Jon French, Gregor Guthrie, Susan Hanson, www.environment-agency.gov.uk Robert Nicholls, Stephen Pearson, Kenneth Pye, Kate Rossington, James Sutherland, Mike Walkden ISBN: 978-1-84911-090-7 Dissemination Status: © Environment Agency – August 2009 Publicly available Released to all regions All rights reserved. This document may be reproduced with prior permission of the Environment Agency. Keywords: Coastal geomorphology, processes, systems, The views and statements expressed in this report are management, consultation those of the author alone. The views or statements expressed in this publication do not necessarily Research Contractor: represent the views of the Environment Agency and the HR Wallingford Ltd, Howbery Park, Wallingford, Oxon, Environment Agency cannot accept any responsibility for OX10 8BA, 01491 835381 such views or statements. (For contractor quality control purposes this report is also numbered SR 694) This report is printed on Cyclus Print, a 100% recycled stock, which is 100% post consumer waste and is totally Environment Agency’s Project Manager: chlorine free. Water used is treated and in most cases Stefan Laeger, Twerton Office and Depot, Lower returned to source in better condition than removed. Bristol Road, Bath, BA2 9ES, 01225 487664 Further copies of this summary are available from our Collaborator(s): publications catalogue: http://publications.environment- British Geological Survey, Kenneth Pye Associates agency.gov.uk or our National Customer Contact Ltd, Newcastle University, Royal Haskoning, University Centre: T: 08708 506506 College London, University of Southampton E: [email protected]. Science Project Number: SC060074/SR1 Product Code: SCHO0809BQVL-E-P ii Science Report – Final Science Report Science at the Environment Agency Science underpins the work of the Environment Agency. It provides an up-to-date understanding of the world about us and helps us to develop monitoring tools and techniques to manage our environment as efficiently and effectively as possible. 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Steve Killeen Head of Science Science Report – Final Science Report iii Executive summary With the advent of climate change, it is vital to understand and predict coastal geomorphological change in order to assess flooding and erosion risks and to plan, appraise and develop sustainable coastal management solutions. Until now, our capability to predict coastal morphological change on a broad scale has been limited and has not always allowed us to fully consider the impacts of coastal management options and climate change in strategic planning and decision-making. New research in this report has sought to develop a framework and conceptual model to predict long-term and large-scale geomorphological evolution, linking our understanding to the treatment of coastal and estuarine environments. Substantial progress has been made in developing conceptual models and in quantitative analysis of coastal geomorphological change. To provide generic tools applicable in any UK location, it is necessary to understand the geomorphological behaviour of the coastal system as a whole and links between its component parts. A functioning coastal system is made up of features which combine and interact over a range of timescales. Coastal features are themselves made up of one or more geomorphological elements or units. These form the basic building blocks of the coastal system and as such are the starting point for this study. The coastal system will also be constrained at a large scale by geological controls, such as headlands, and supply of sediments forming the main geomorphological features. A framework for assessing coastal geomorphological change is supported by the conceptual models of geomorphological features and elements which form the basis for assessing the impacts of coastal management options, including the cessation of management. Answers can be delivered in a consistent fashion for any location. The conceptual model was implemented numerically to ‘proof of concept’ level using existing systems-based models applied to a coupled coast and estuary system; this demonstrated the benefits of the approach and showed how the results could be used to inform practical coastal management decisions. Expert geomorphological analysis and systems analysis were also used to evaluate existing engineering tools and methods for quantifying coastal change. A graphical method of mapping coastal geomorphological systems and interactions was developed to aid discussions with outside groups of how a coastal system works. The mapping approach is scale independent and is a useful starting point for analysis of geomorphological systems and for strategic planning. It helps to construct baseline knowledge and formal understanding, highlights uncertainty and removes the ‘black box’ nature of existing coastal prediction methods. The approach was applied to three coastal locations and easy-to-follow guidance on its use was produced. Independent assessment of the approach was carried out at another location which confirmed the approach’s usefulness in shoreline management plans (SMP) in identifying broad scale links, developing skills and training for coastal managers and offering a means of communication between different partners. In the long-term, the outputs from this project will enable better planning of coastal works and better understanding of the consequences of not intervening. It will help coastal practitioners, local authorities, Environment Agency, Department for Environment, Food and Rural Affairs (Defra) and others involved in strategic planning to assess risks and plan for change. This report also makes a number of recommendations for the application and development of existing methods for quantifying coastal change. iv Science Report – Final Science Report This final science report of project SC060074 is based on work carried out with the Environment Agency by HR Wallingford, Royal Haskoning, University College London, University of Southampton, Kenneth Pye & Associates, Newcastle University and British Geological Survey. The report should be read in conjunction with Whitehouse et al. (2008), Walkden and Rossington (2009), and French and Burningham (2009). A project website is also available at www.coastalgeomorphology.net Science Report – Final Science Report v Acknowledgements The project is grateful for advice received from Steering Group members (Tim Kermode, Suresh Surendran, Stefan Laeger, Owen Tarrant) and those who contributed to the consultation process: Graham Lymbery (Sefton District Council) – who also kindly participated in a test of the system mapping approach, Rod Jones (Countryside Council for Wales), Kerry Keirle (Welsh Assembly Government), Lee Swift, Geoff Astle, Karen Thomas, Gary Watson (Environment Agency), Emyr Williams (Pembrokeshire County Council), Stewart Rowe (Scarborough Borough Council). We would also like to thank the Steering Group and Jim Hall from University of Newcastle for reviewing this report. vi Science Report – Final Science Report Contents 1. Preamble 1 1.1. Introduction 2 1.2. Objectives and outline of report 5 2. Aim, audience and FCRM context for the report 6 2.1. Objectives and target audience 6 2.2. Project goals and benefits 6 2.3. Modelling coastal evolution for coastal management 8 3. Framework for incorporation of coastal geomorphology into coastal management