Transcript 1.Intro 2.Climate Change 3.Effects 4.Coastal Engineering

Climate Change Conference – Budapest, Hungry
February 2009
Climate change from a Coastal
Engineering perspective
Margaret R. Boshek
Coastal and Marine Engineering & Management
TU Delft, Delft NL
ACKNOWLEDGEMENTS
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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
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Climate Change
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)
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Coastal Systems
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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)
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Coastal systems are considered as the interacting low-lying areas
and shallow coastal waters, including their human components
(Nicholls et al, 2007)
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Nicholls, R.J., (IPCC), 2007
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Kay and Alder, 2004
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
Nicholls, 2000
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
Estuaries
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1.Intro
‘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
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
ESTUARY ROLLOVER
Landward
Translation
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
Average depth
increases
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
Sediment Infilling
Average depth
reduces
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
Sediment Expulsion
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Sea-Level Rise
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
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Wave Climate
Dune Migration
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
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Storm Intensity & Frequency
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Consequences on the Coastline
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
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Increase in flooding risk for shallow areas
5.
Reduced effects of existing coastal protection
6.
Salt water intrusion in ground water
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Influence on harbor constructions
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Increases the rate of recession of natural cliffs/beaches
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Changes in human pressures
10.
Changes in water temperature
1.Intro
2.Climate Change
3.Effects
Edelvang, 2007
4.Coastal Engineering
5.Way Forward
The Need for Educated Coastal Engineers
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
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Development of World Population
(Black indicates coastal population)
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Areas Most Vulnerable to Sea Level Rise
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1.Intro
Bangladesh
Egypt
Gambia
Indonesia
Maldives
Mozambique
Pakistan
Senegal
Surinam
Thailand
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
Adaption of Developed Coastlines
Retreat
Accommodation
Protection
soft or hard
Nicholls, 2000
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).
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
French, 1997
5.Way Forward
“Building for the Future”
1.
Recognizing climate trends and designing accordingly for the life of
the project
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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
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Education for coastal engineers on climate changes, effects, and
solutions
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Designing adjustable structures or using materials that allow for
easy renovation
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
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
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
SUGGESTED WAYS FORWARD
(on a regional scale)
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Public Awareness
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Establishment of coastal observatories
(e.g. Channel Coastal Observatory (CCO), Southampton
www.channelcoast.org
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Industry/Academia linkages and collaboration (e.g.
marine climate change impacts - www.mccip.org.uk/arc
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Training and education in coastal processes and
management (of risk)
1.Intro
2.Climate Change
3.Effects
4.Coastal Engineering
5.Way Forward
QUESTIONS?