Transcript Biogeophysical Effects of Sea Level Rise

Vulnerability and Adaptation
Assessments Hands-On
Training Workshop,
Paraguay, August 14-18 2006
Impact, vulnerability and adaptation
assessment for coastal zones
Outline
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Drivers & impacts on coastal areas
Adaptation options
V&A tools & data sources
Integrating mechanisms
Conclusions
Drivers & impacts on coastal
areas
Climate Change and
Coastal Resources
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Coastal resources will be affected by a number of
consequences of climate change, including:
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Higher sea levels
Higher sea temperatures
Changes in precipitation patterns and coastal runoff
Changed oceanic conditions
Changes in storm tracks, frequencies, and intensities
The Main Biophysical Effects of
Relative Sea Level Rise
Table 5.2. The main biophysical effects of relative sea level rise, including relevant interacting factors. Some
factors (e.g., sediment supply) appear twice because they may be influenced by both climate and nonclimate
factors (adapted from Nicholls, 2002).
Other relevant factors
Biogeophysical effect
Climate
Inundation, flood
and storm
damage
Nonclimate
Surge
Wave and storm climate, morphological
changes, sediment supply
Sediment supply, flood management,
morphological changes, land claim
Backwater effect
(river)
Runoff
Catchment management and land
use
Wetland loss (and change)
CO2 fertilization
Sediment supply
Sediment supply, migration space,
direct destruction
Erosion
Sediment supply, wave and storm climate
Sediment supply
Surface waters
Runoff
Catchment management and land
use
Groundwater
Rainfall
Land use, aquifer use
Rainfall
Land use, aquifer use
Saltwater
intrusion
Rising water tables/impeded drainage
Some Climate Change Factors
Table 5.1. Some climate change and related factors relevant to coasts and their
biogeophysical effects (taken from Nicholls, 2002)
Climate factor
Direction of change
Biogeophysical effects
Sea water
temperature (of
surface waters)
Increase
Increased coral bleaching; migration of coastal species
toward higher latitudes; decreased incidence of sea ice
at higher latitudes
Precipitation
intensity/run-off
Intensified hydrological cycle, with
wide regional variations
Changed fluvial sediment supply; changed flood risk in
coastal lowlands; but also consider catchment
management
Wave climate
Poorly known, but significant
temporal and spatial variability
expected
Changed patterns of erosion and accretion; changed
storm impacts
Storm track,
frequency, and
intensity
Poorly known, but significant
temporal and spatial variability
expected
Changed occurrence of storm flooding and storm
damage
Atmospheric CO2
Increase
Increased productivity in coastal ecosystems;
decreased CaCO3 saturation impacts on coral reefs
Current Global Predictions
of Sea Level Rise
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IPCC Third Assessment Report (TAR) range
for global-mean rise in sea level is between
9 cm and 88 cm by 2100
Change outside this range is possible,
especially if Antarctica becomes a significant
source
There is a “commitment to sea level rise”
even if atmospheric GHG concentrations are
stabilized
Global-Mean Sea Level Rise
1990 to 2100 (SRES scenarios)
Houghton et al., 2001
Processes
Controlling
Sea-Level
Change
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Relative sea-level
changes
Land Subsidence Mexico City
Source: http://ga.water.usgs.gov/edu/earthgwlandsubside.html
Subsidence in Mexico City and
the Chalco Plain
Source: Adapted from Ortega et al., 1993
Factors in Local Predictions
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Relative sea level rise: global and
regional components plus land
movement
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Land uplift can counter any global sea
level rise
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Land subsidence can exacerbate any
global sea level rise
Other dynamic oceanic and climatic
effects cause regional differences
(oceanic circulation, wind and pressure,
and ocean-water density differences add
additional component)
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Sea Level Rise at New York City
1850 to 2100
8
Sea Level (m)
Observations
6
1850
McCarthy et al., 2001
Scenarios
IPCC TAR range
due to SRES
emission scenarios
1900
1950 2000 2050
Time (yrs)
2100
Other Climate Change
(Hurricane Katrina)
Source: http://www.ncdc.noaa.gov/oa/climate/research/2005/aug/hazards.html
Gulfport, Mississippi, July 05
Grand Casino, Gulfport 21 Sept 2005
Caman, Peru, and Tsunami
Vulnerability
http://www.intute.ac.uk/sciences/worldguide/html/824_satellite.html
Atolls, Belize
Source: http://home.swbell.net/skyisles/islands.html
Coral Impacts
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“Recent global increases in reef ecosystem
degradation and mortality are exceeding the adaptive
capacity of coral reef organisms and communities.
The severity of this crisis will only intensify with future
changes in the global climate.
While the net effects of climate change on coral reefs
will be negative, coral reef organisms and
communities are not necessarily doomed to total
extinction.
Multiple environmental management strategies, from
local to global, will be necessary to ensure the longterm sustainability of the world’s coral reef
ecosystems.”
Buddemeier et al, 2004
Population and
Population
Density vs.
Distance and
Elevation
in 1990
Coastal Megacities (>8 million people)
Forecast for 2010
Tianjin
Dhaka
Seoul
Osaka
Istanbul
Tokyo
New York
Shanghai
Manila
Los Angeles
Bangkok
Lagos
Mumbai
Lima
Karachi
Buenos Aires
Rio de Janeiro
Madras
Jakarta
Calcutta
Rio de Janeiro's waterfront, 1919
http://en.wikipedia.org/wiki/Image:Rio_de_Janeiro%27s_waterfront%2C_1919.jpg
Rio de Janeiro, Brazil
http://en.wikipedia.org/wiki/Image:Rio_de_Janeiro-Ipanema_Beach.jpg
Havana, Cuba
http://www.intute.ac.uk/sciences/worldguide/html/824_satellite.html
Controls on Coastal Position
antecedent
physiography
sea-level
change
littoral sediment
supply (±ve)
boundary conditions (external)
fluvial-delta inlet bypassing
C
D resuspension & inlet bypassing
lagoon basin mud
mid-shelf mud
lower shoreface
marine sand wedge
bypassing
A
inlet
inner-shelf sand
B
upper
shoreface
transport
cross-shelf
backbarrier
coastal tract
Rio de la Plata
http://www.intute.ac.uk/sciences/worldguide/html/824_satellite.html
SeaWiFS:
sediment
plumes off the
coast of Chile
http://www.intute.ac.uk/sciences/worldguide/html/824_satellite.html
Beach Erosion, Barbados
Before Storm
After Storm
Source: http://www.unesco.org/csi/act/cosalc/shore-ero.htm
Biogeophysical Effects
of Sea Level Rise
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Displacement of coastal lowlands and
wetlands
Increased coastal erosion
Increased flooding (frequency and
depth)
Salinization of surface and
groundwaters
Plus others
Ecosystem Loss
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Inundation and displacement of wetlands
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Areas provide
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e.g., mangroves, saltmarsh, intertidal areas
Flood protection
Nursery areas for fisheries
Important for nature conservation
Loss of valuable resources, tourism
Coastal Ecosystems at Risk
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KEY:
mangroves, o saltmarsh, x coral reefs
Reefs and Mangroves, Latin America and
Caribbean
http://www.unep-wcmc.org/marine/data/coral_mangrove/marine_maps_main.html
United Nations Environment Programme
Interactive Mapping Tool
Source: http://bure.unep-wcmc.org/imaps/marine/mangroves/viewer.htm
Mangroves as indicators of
coastal change, Brazil
Coastal Squeeze
(of coastal wetlands)
Sea Level Rise
(a) no hard defenses
(b) hard defenses
Socioeconomic Impacts
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Loss of property and land
Increased flood risk/loss of life
Damage to coastal protection works and other
infrastructure
Loss of renewable and subsistence resources
Loss of tourism, recreation, and coastal habitats
Impacts on agriculture and aquaculture through
decline in soil and water quality
Adaptation Options
Responding to Coastal Change
(including sea level rise)
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Retreat
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Accommodation
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Protect
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Soft
Hard
Adaptation Methods
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Retreat
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Managed retreat
Relocation from high risk zones
Accommodation
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Public awareness
Natural disaster management planning
Adaptation Methods
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Protect
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Hard options
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Revetments, breakwaters, groins
Floodgates, tidal barriers
Soft options
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Beach/wetland nourishment
Dune restoration
(continued)
Beach Nourishment, Nevis
Eroded Beach
Re-nourished Beach
Source: http://www.unesco.org/csi/act/cosalc/shore-ero.htm
Example Approach to
Adaptation Measures
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Climate change predictions
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Rise in sea level
Increase in number and intensity of tropical
weather systems
Increase in severity of storm surges
Changes in rainfall
Example Approach to
Adaptation Measures
(continued)
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Coastal impacts
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Damage to property/infrastructure
Damage/loss of coastal/marine ecosystems
Destruction of hotels and tourism facilities
Increased risk of disease
Damage/loss of fisheries infrastructure
General loss of biodiversity
Submergence/inundation of coastal areas
Example Approach to
Adaptation Measures
(continued)
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Adaptation (retreat, protect, accommodate)
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Improved physical planning and development
control
Strengthening/implementation of EIA
regulations
Formulation of Coastal Zone Management
Plan
Monitoring of coastal habitats, including
beaches
Formulation of national climate change policy
Public awareness and education
Shoreline Management and Adaptation
Proactive
Adaptation
Coastal
Adaptation
(IPCC)
UK Shoreline
Management
(Defra)
Increasing
robustness
Protect
Hold the line
Increasing
flexibility
Accommodate
Advance the line
Enhancing
adaptability
Retreat
Managed
realignment
Reversing
maladaptive
trends
Improving
awareness and
preparedness
No active
intervention
Flood plain
mapping and
flood warnings)
V&A Tools & Data Sources
Coastal Vulnerability
Assessment
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Principles
Older tools
Top down
Bottom up
Methods to Assess Impacts
of Sea Level Rise
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Sea level rise & climate change scenarios
Screening assessment
Erosion
Flooding
Top-down
Bottom up
Screening Assessment
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Rapid assessment to highlight possible impacts
of a sea level rise scenario and identify
information/data gaps
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Qualitative or semiquantitative
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Steps
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Collation of existing coastal data
Assessment of the possible impacts of a high sea
level rise scenario
Implications of future development
Possible responses to the problems caused by
sea level rise
Step 1: Collation of
Existing Data
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Topographic surveys
Aerial/remote sensing images – topography/
land cover
Coastal geomorphology classification
Evidence of subsidence
Long-term relative sea level rise
Magnitude and damage caused by flooding
Coastal erosion
Population density
Activities located on the coast (cities, ports,
resort areas and tourist beaches, industrial
and agricultural areas)
Step 2: Assessment of Possible Impacts of
High Scenario Sea Level Rise
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Four impacts are considered
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Increased storm flooding
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Beach/bluff erosion
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Wetland and mangrove inundation and loss
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Salt water intrusion
Step 3: Implications of Future
Developments
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New and existing river dams and impacts on
downstream deltas
New coastal settlements
Expansion of coastal tourism
Possibility of transmigration
Step 4: Responses to the
Sea Level Rise Impacts
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Planned retreat (i.e., setback of defenses)
Accommodate (i.e., raise buildings above
flood levels)
Protect (i.e., hard and soft defenses,
seawalls, beach nourishment)
Screening Assessment Matrix
Biophysical vs. Socioeconomic Impacts
Biophysical
Impact of
Sea Level
Rise
Inundation
Erosion
Flooding
Salinization
Others?
Socioeconomic impacts
Tourism
Human
Settlements
Agriculture
Water
Supply
Fisheries
Financial
Services
Human
Health
Others?
Beach Erosion, Anguilla
Pre Hurricane
Post Hurricane
Source: http://www.unesco.org/csi/act/cosalc/shore-ero.htm
Bruun “Rule”
Limitations of the
Bruun “Rule”
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Only describes one of the processes
affecting sandy beaches
Indirect effect of mean sea level rise
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Estuaries and inlets maintain equilibrium
Act as major sinks
Sand eroded from adjacent coast
Increased erosion rates
Response time – best applied over long
timescales
Flooding
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Increase in flood levels due to rise in sea
level
Increase in flood risk
Increase in populations in coastal floodplain
Adaptation
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Increase in flood protection
Management and planning in floodplain
Coastal Flood Plain
Global Impacts of Coastal Flooding in
2050 – Effects of Mitigation
People flooded (Millions/yr)
The Thames Barrier
Flood Methodology
Global Sea-level
Rise Scenarios
Subsidence
Storm Surge
Flood Curves
Coastal
Topography
Relative Sea-Level
Rise Scenarios
Raised Flood Levels
Population
Density
Size of Flood
Hazard Zones
Protection Status
People in the
Hazard Zone
(“EXPOSURE”)
Average Annual
People Flooded,
People to Respond
(“RISK”)
(1in 10, 1 in100, etc.)
Models
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Top Down
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Older Models
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COSMO
RamCo
Common Methodology
Integrated Models
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DIVA: Dynamic and Interaction Vulnerability
Assessment from DINAS-Coast Project
RegIS2 : Development of a metamodel tool for
regional integrated climate change management
Bottom-up approaches
Saltmarsh Losses to 2050
Present day loss rate
Low Climate
Change
High Climate
Change
Bottom Up Models
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Detailed local assessments
UK erosion assessment
Australian approaches
Relative assessment approach ‘Pacific
Methodology’
Approach Selection
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‘Relative’ vs ‘absolute assessments’
Pragmatic approach and selection
Example selection criteria:
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Type of coast
Management issues
Time/budget
Access to expertise & data
Integration into adaptation
UK Planning Assessment
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Ongoing investigation and formulation of policy
Requires information on
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Role of major processes in sediment budget
 Including human influences
 Other climate change impacts
Example of assessment from the UK
Combined flood hazard and erosion assessment
Erosion
Often Exported Alongshore
Goals for Planning Assessment
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For future climate and protection scenarios, explore
interactions between cliff management and flood risk
within sediment sub-cell (in Northeast Norfolk)
In particular, quantify
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Cliff retreat and associated impacts
Longshore sediment supply/beach size
Flood risk
Integrated flood and erosion assessment
Method for Planning
Assessment
Scenarios
Climate Change,
Sea-Level Rise
Scenarios
Protection,
Socio-economic
Scenarios
Overall
Assessment
Analysis
Regional
Wave/Surge
Models
SCAPE
Regional
Morphological
Model
Flood
Risk Analysis
(LISTFLOOD-FP)
SCAPE GIS
Data Storage
Cliff Erosion
Analysis
Integrated
Cell-scale
Assessment
Bathymetry and
Wave Modelling
Offshore sandbank
Nearshore
sandbank
Future Policy
Maintain Defenses, 6 mm/yr Sea Level Rise
Distance along baseline, km
5 year stages
Average over 50 years
35
35
30
30 S
Sheringham
25
25
Cromer
20
20
C
O
Overstrand
Trimmingham
T
15
15
Mundesley
M
10
10
Bacton
B
5
0
-150
5
-100
-50
Recession distance
0
0
Happisburgh
H
0
0.5
1
1.5
2
Recession rate (m/A)
2.5
Erosion Visualization
Protection Abandoned (10 year time steps)
Australian Coastal Vulnerability
Approaches
C 10
A
100
D
accretion
B
E
erosion
R=S(L/(B+h))=(S)1/tanØ
Kay et al, 2005. Graphics by Colin Woodroffe.
Probabilistic Beach Erosion
Cowell et al (in press)
Engineers Australia Matrix
Engineers Australia Approach
National assessment
Local assessment
Higher sea level
K1 K2 K3
K4 K5
Estuary
K6
S1
Beach
S2
S3
S4
K1
S5
S6
S7
S9
S10
S11
S12
S13
K3
K1 K3
K4
S1
S1
S2
S2
S3
S4
S7
S8
S9
S10
Coral bleaching
S11
Engineers Australia (2004) in Kay et al, 2005. Graphics by Colin Woodroffe.
K4
Relative Assessment
From Kay & Hay, 1993
Group Consultation Processes
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Expert consensus building
Stakeholder engagement processes
Can be as structured or unstructured as
required
Climate Change Adaptation
Through Integrated Risk Reduction
http://www.waikato.ac.nz/igci/ccairr/ccairr.htm
Barriers to Conducting
Vulnerability Assessments
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Incomplete knowledge of the relevant
processes affected by sea level rise and their
interactions
Insufficient data on existing physical
conditions
Difficulty in developing the local and regional
scenarios of future changes
Lack of appropriate analytical methodologies
Variety of questions raised by different sociopolitical conditions
Data Sources
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IPCC Data Distribution Centre
Sea level data
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Remotely sensed data
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Permanent service for mean sea level
GLOSS – Global Sea-Level Observing System
Land Processes Distributed Active Archive Centre
(NASA)
Shuttle radar topography mission
Coastal data
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Global mapping e.g. http://www.unep-wcmc.org
Coastal specialists in your region e.g. Un
GLOSS Tide Gauges
http://ioc3.unesco.org/gloss-south-america/
GTOPO30
Global Digital
Elevation
Model
Data Sources
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Local observational data
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Sea level measurements
Elevation/topography
Wave recording
Aerial photography
Habitat mapping
Integrating Mechanisms
Integrated Coastal Zone
Management (ICZM)
Basic Features of ICZM
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Establishes institutions designed to overcome
sectoral fragmentation
Promotes harmonization & consistency of decisions,
but does not supplant sectoral management
Recognizes the distinctive, interrelated nature of
watersheds, the coast, and ocean
Source: Jim Good
Global ICZM Activity
Global ICZM Activity
700
600
500
-National and sub
national
International
400
300
200
100
0
1993
2000
2002
From Sorensen 1993, 1997, 2000, 2002
Wide range of literature
Books
Papers
Websites
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Planning Frameworks
Scales of Coastal Management
Plans
Level o f Plan (scale)
Key Role
International
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Transboundary issues
Creating a common p urpose
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Administrative arrangements
Setting national objectives and
Focus on prio rities
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Translating internationa l and national goals and
objectives to local outcomes.
Aggregate local needs and issues to formulate
national and internationa l prio rities and programs
Whole -of-jurisdiction
Regional
1
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principles
Local
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Community involvement i
options
Site
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Managing well defined problems
Tangible results o f all plannin g levels can be seen
n setting management
Example mitigation policy Western Australia (2003)
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“These setback guidelines provide direction for the siting of
development, including subdivision and strata subdivision,
on the Western Australian coast as defined in this Policy.
The specific objectives of these guidelines are to provide a
setback that protects development from coastal processes
by:
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absorbing the impact of a severe storm sequence;
allowing for shoreline movement;
allowing for global sea level rise; and
allowing for the fluctuation of natural coastal processes. “
Western Australian Coastal
Policy - Bruun Rule Component
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“The setback to allow for sea level rise is based on
the mean of the median model of the latest
Assessment Report of the IPCC Working Group
(currently, the Third Assessment Report of the IPCC
Working Group, January 2001). The vertical change
predicted by the current model between the years of
2000 and 2100 is 0.38 m. A multiplier of 100, based
on the Bruun Rule shall be used and gives a value
for 38 m for sandy shores. For other shore types,
this factor shall be assessed in regard to local
geography.”
Recap
1.
2.
3.
4.
5.
Drivers & impacts on coastal areas
Adaptation options
V&A tools & data sources
Integrating mechanisms
Conclusions
Concluding Remarks
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Sea level rise could be a serious problem,
but the uncertainties are large
Impacts are strongly influenced by human
choice
Reducing GHG emissions reduces but does
not avoid sea level rise impacts
Preparing to adapt would seem prudent, in
the context of multiple stresses and
managing existing problems