Author

Professor Richard Dawson

Date

December 2002-March 2003; 2005

Project Type

Research

Subject

Water Resources Development

Datasets

OS Panorama; OS Postcode data

Sources: Digimap

Dates/Editions: All available.

Scales: All available.

Related Subjects

Civil Engineering; Physical Geography

Key Words

Climate change impacts; Risk analysis

Publishing Institution

School of Civil Engineering and Geosciences, Newcastle University

Funded by: European Commission FP5: Atlantis Project (EVK2-CT-2002-00138)

Summary

The world’s coastal areas are heavily developed. London, situated on the tidal Thames is susceptible to storm surges. Currently it is protected by the Thames barrier and a network of defences and warning systems. Future upgrades to the defence system are being considered at present. Collapse of the Western Antarctic Ice Sheet could cause global mean sea level to rise by up to 6m in 100 years – 5m more than the upper bound of 1m estimated by the Intergovernmental Panel on Climate Change that is likely to be used in any design. The impacts of such extreme sea level rise could have a disastrous impact on coastal cities such as London. Although the probability of this occurring is small the mechanism is credible. This paper explores and quantifies the impacts the likely impacts in the Thames Estuary for a number of adaptation scenarios using a simple hydrodynamic model. Whilst this analysis has, for the first time, connected mechanisms of abrupt climatic change and sea level rise with hydrodynamic modelling and quantification of its impacts, the process has identified a number of areas of current knowledge, related to both climatic and human processes that merit further research in order to move towards a risk-based decision-making framework for long term climate adaptation programmes.

Aims & Objectives

The aim of the project was to quantify changes to impacts from flooding (in terms of people at risk, damage to property etc.) for extreme sea level rise scenarios. This was a brief modelling study and this information was subsequently used to explore the effectiveness of adaptation options to this sea level rise and explore society’s capability to respond to such extreme events.

Methodology

The main activity was setting up an inundation model on a very large scale, and to simulate extreme events. The assumptions made and methods used in the hydrodynamic modelling are described in detail in the referenced paper. Damages to property were estimated for each postcode using information on the number of residential and non-residential properties in each postcode area and intersecting this data with water levels from the hydrodynamic model and national flood damage estimate from the Multi-Coloured Manual published by Middlesex University. Damages for today’s configuration of flood defences was compared with other adaptation options, such as an outer defence barrier.

Ideally, more accurate topographical, and property location (eg. AddressPoint) data would be used (LiDAR, IfSAR etc.) but the time-scale and budget of the project made this impossible. Fortunately the scale of the flooding analysis and the resolution required for the results meant that this additional accuracy was not essential.

Results/Outcome

Dawson, R.J., Hall, J.W., Bates, P.D., and Nicholls, R.J.  Quantified Analysis of the Probability of Flooding in the Thames Estuary under Imaginable Worst-case Sea Level Rise Scenarios. International Journal of Water Resources Development 2005, 21(4), 577-591. Available for free download here.

Lonsdale K, Downing T, Nicholls R, Parker D, Vafeidis A, Dawson RJ, Hall JW. Plausible responses to the threat of rapid sea-level rise in the Thames Estuary. Climatic Change 2008, 91(1-2), 145-169.

References & Acknowledgements

Funded by: The European Commission FP5: Atlantis Project (EVK2-CT-2002-00138)