1. Climate change from a Coastal Engineering perspective Margaret R. Boshek Coastal and Marine Engineering & Management TU Delft, Delft NL Margaret R. Boshek Coastal and Marine Engineering & Management TU Delft, Delft NL Climate Change Conference – Budapest, Hungry February 2009 Climate Change Conference – Budapest, Hungry February 2009

2. ACKNOWLEDGEMENTS Angel Borja, AZTI, Spain Amaia Lopez Escolar and Marta Pascual Altares, MER, Spain Alan Brampton/Ian Townend, HR Wallingford, U.K. Karen Edelvang, DHI, Denmark Robert Nicholls, Mikis Tsimplis & Peter Challenor, University of Southampton, U.K. José Jiménez, UPC, Barcelona, Spain University of Cantabria, Spain Wenjing Xie, University of Nanjing Kate Davis, SOES, University of Southampton Micheal Collins, SOES, University of Southampton Marcel Stive, CITG, TU Delft

4. 1.Intro 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward

6. 2.Climate Change 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward A change in the state of the climate that can be identified (e.g. using statistical tests), by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. It refers to any change in climate over time, whether due to natural variability or as a result of human activity. (IPCC Synthesis Report, 2007) Climate Change

7. 2.Climate Change 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward

10. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward

11. The Coastal Zone is that space in which terrestrial environments influence marine (or lacustrine) environments and vice-versa. The coastal zone is of variable width and may also change in time (Carter, 1998) Coastal systems are considered as the interacting low-lying areas and shallow coastal waters, including their human components (Nicholls et al, 2007) 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Coastal Systems

12. Nicholls, R.J., (IPCC), 2007 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward

13. Kay and Alder, 2004

14. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

15. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

16. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

17. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

18. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise Nicholls, 2000

19. ‘An estuary is a semi-enclosed coastal body of water which has free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage’ (Pritchard, 1952) Each estuary is a unique result of geology, climate, marine and ecological conditions and the accumulative effect of a number of man-made works Estuaries are complex systems that react strongly to modifications of either the surrounding basin or the adjacent sea 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise Estuaries

20. Landward Translation ESTUARY ROLLOVER 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

21. Average depth increases 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

22. Average depth reduces 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise Sediment Infilling

23. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise Sediment Expulsion

24. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Sea-Level Rise

25. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Wave Climate Waves are influenced by bottom bathymetry Deeper water allows for greater wave energy to impact the coast causing realignment Water level higher on structures as well as wave run-up higher on coastal defenses Changes in mean annual wave height Changes in extreme annual wave height Changes in wave direction, hence in beaches

26. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Dune Migration Wave Climate

27. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Storm Intensity & Frequency Increased ocean temperatures creates greater & stronger cyclones Intensified and heightened storm surge Increased offshore storm intensity translates to more ocean swell

28. 3.Effects 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Storm Intensity & Frequency

29. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward 1.Erosion of the coastline because of sea level rise 2.Changes in wind patterns and storms leading to increased/changed erosion patterns 3.Changes in wave patterns and extreme events 4.Increase in flooding risk for shallow areas 5.Reduced effects of existing coastal protection 6.Salt water intrusion in ground water 7.Influence on harbor constructions 8.Increases the rate of recession of natural cliffs/beaches 9.Changes in human pressures 10.Changes in water temperature Edelvang, 2007 Consequences on the Coastline

30. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward The Need for Educated Coastal Engineers

31. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Hurricane Katrina Disaster Levee design did not incorporate allowances for future changes in sea level or storm intensity Levees not properly maintained/monitored Hurricane was only catalyst for New Orleans disaster; failure of levees caused most damage Hurricane strength can be linked to increased storm intensity due to climate change One of costliest natural disaster in US history Brought coastal protection issues to the forefront

32. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Development of World Population (Black indicates coastal population)

33. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Areas Most Vulnerable to Sea Level Rise Bangladesh Egypt Gambia Indonesia Maldives Mozambique Pakistan Senegal Surinam Thailand

34. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Nicholls, 2000 Retreat Accommodation Protection soft or hard Adaption of Developed Coastlines

35. 4.Coastal Engineering 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward Coastal defense management and planning: options 1.Do nothing (i.e. leave the coast alone to find its own equilibrium state); 2.Undertake managed realignment (i.e. move the defense inland to allow the creation of new habitats); 3.Opt for partial set-back (allowing parts of the coast to erode while protecting others); 4.Maintain existing defenses (reinforce and repair); 5.Build new defenses (protecting previously unprotected parts of the coast); 6.Advance seaward (i.e. offshore breakwaters). French, 1997

36. 1.Recognizing climate trends and designing accordingly for the life of the project 2.Adjustments to human impacts on the climate may take many years to take affect 3.Monitoring existing sea defenses and making adjustments/replacements where necessary to ensure system strength 4.Education for coastal engineers on climate changes, effects, and solutions 5.Designing adjustable structures or using materials that allow for easy renovation “Building for the Future” 5.Way Forward 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward

37. Awareness: IPCC Fourth Assessment Report Chap 6-1 –Coasts are experiencing the adverse consequences of hazards related to climate and sea level –Coasts will be exposed to increasing risks over coming decades due to many compounding climate change factors –The impact of climate change on coasts is exacerbated by increasing human induced pressures Chap 6-2 –Adaptation for the coasts of developing countries will be more challenging than for coasts of developed countries due to constraints on adaptive capacity –Adaptation costs for vulnerable coasts are much less than the costs of inaction –The unavoidability of sea level rise even in the long term frequently conflicts with present day human development patterns and trends

38. 5.Way Forward 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering 5.Way Forward SUGGESTED WAYS FORWARD (on a regional scale) Public Awareness Establishment of coastal observatories (e.g. Channel Coastal Observatory (CCO), Southampton www.channelcoast.org Industry/Academia linkages and collaboration (e.g. marine climate change impacts - www.mccip.org.uk/arcwww.mccip.org.uk/arc Training and education in coastal processes and management (of risk)

39. QUESTIONS?