1a.1 vulnerability and adaptation assessments hands-on training workshop coastal resources:...
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1A.1
Vulnerability and Adaptation Assessments Hands-On
Training Workshop
Coastal Resources: Analytical Approaches
Outline
Introduction Sea level rise
Predictions and uncertainties Scenarios Global processes Local uncertainties Impacts
Adaptation and shoreline management
Outline (continued)
Methods to assess impacts of sea level rise Levels of assessment
Screening Vulnerability Planning
Review of African region situation Models Data sources DIVA
Climate Change and Coastal Resources
Coastal resources will be affected by a number of consequences of climate change, including: Higher sea levels Higher sea temperatures Changes in precipitation patterns and coastal
runoff 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).
Biogeophysical effect
Other relevant factors
Climate Nonclimate
Inundation, flood and storm damage
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
Saltwater intrusion
Surface waters Runoff Catchment management and land use
Groundwater Rainfall Land use, aquifer use
Rising water tables/impeded drainage Rainfall Land use, aquifer use
Some Climate Change Factors
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
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
Atmospheric CO2 Increase Increased productivity in coastal ecosystems; decreased CaCO3 saturation impacts on coral reefs
Current Global Predictions of Sea Level Rise
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-LevelChange
Relative sea-level changes
Ocean Water Volume
Controlled by: Ocean temperature – thermal expansion Melting of land-based ice
Small glaciers Greenland Antarctica
The hydrological cycle (including human influence)
Uncertainty in Local Predictions
Relative sea level rise: global and regional components plus land movement Land uplift will counter any global sea level rise Land subsidence will 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)
Sea Level Rise at New York City1850 to 2100
IPCC TAR range due to SRES emission scenarios
McCarthy et al., 2001
Land Subsidence
Other Climate Change(Hurricane Katrina)
Elevation and Population Density Maps for Southeast Asia
Population and Population Density vs.
Distance and Elevationin 1990
Istanbul
LagosLima
Buenos Aires Rio de JaneiroMadras
KarachiJakarta
Calcutta
MumbaiBangkok
ManilaShanghai
Osaka
Tokyo
Seoul
Tianjin
Dhaka
New York
Los Angeles
Coastal Megacities (>8 million people)Forecast for 2010
National Vulnerability Profiles
ANTIG UA
WITH M EASURES
WITH M EASURES
NO M EASURES
NO M EASURES
p e o p lea ffe c te d
p e o p lea ffe c te d
p ro te c tio nc o sts
p ro te c tio nc o sts
p e o p lea t risk
p e o p lea t risk
we tla nda t lo ss
we tla nda t lo ss
la nda t lo ss
la nda t lo ssc a p ita l
va luea t lo ss
c a p ita lva luea t lo ss
p e o p lea t risk
p e o p lea t risk
ARG ENTINA
NIG ERIA
VENEZUELA
b a se d o n e xp e rt jud g e m e nt
b a se d o n a na lyse s
LO W
Vulne ra b ility p ro file c la sse s
M EDIUMHIG HC RITIC AL
URUG UAY
TO NG A
SEYC HELLES
SENEG AL
PO LAND
NEVIS
NETHERLANDS
M AURITIUS
M ARSHALLS
KIRIBATI
J APAN
G UYANA
EG YPT
BENIN
BANG LADESH
Deltaic Regions
Atolls
Biogeophysical Effects of Sea Level Rise
Displacement of coastal lowlands and wetlands
Increased coastal erosion Increased flooding (frequency and depth) Salinization of surface and groundwaters Plus others
Socioeconomic Impacts
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
Definition of Impacts
Potential impacts
Sea level rise
Initial impacts
Residual impacts
Reactive adaptation
Anticipatory adaptation
Shoreline Management and Adaptation
Proactive Adaptation
Coastal Adaptation (IPCC)
Shoreline Management (Defra)
Increasing robustness
Protect Hold the line
Increasing flexibility Accommodate Advance the line
Enhancing adaptability
Retreat Managed realignment
No active intervention
Reversing maladaptive trends
(Project appraisal methods)
Improving awareness and preparedness
(Flood plain mapping and flood warnings)
Responding to Coastal Change(including sea level rise)
Retreat
Accommodation
Protect Soft Hard
Shoreline Management and Adaptation (2)
Proactive Adaptation
Coastal Adaptation (IPCC)
Shoreline Management
Increasing robustness
Protect Hold the line
Increasing flexibility Accommodate Advance the line
Enhancing adaptability
Retreat Managed realignment
No active intervention
Reversing maladaptive trends
(Project appraisal methods)
Improving awareness and preparedness
(Flood plain mapping and flood warnings)
Adaptation Methods
Retreat Managed retreat Relocation from high risk zones
Accommodation Public awareness Natural disaster management planning
Adaptation Methods (continued)
Protect Hard options
Revetments, breakwaters, groins Floodgates, tidal barriers
Soft options Beach/wetland nourishment Dune restoration
Example Approach to Adaptation Measures
Caribbean small island developing country Climate change predictions
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)
Coastal impacts 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)
Adaptation (retreat, protect, accommodate) 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
Methods to Assess Impacts of Sea Level Rise
Sea level rise scenarios Levels of assessment
Screening assessment Vulnerability assessment Erosion Flooding Coastal wetland loss Planning assessment
Coastal Vulnerability andRisk Assessment
Three levels of assessment Screening assessment (3-6 months) Vulnerability assessment (1-2 years) Planning assessment (ongoing)
Screening Assessment
Rapid assessment to highlight possible impacts of a sea level rise scenario and identify information/data gaps
Qualitative or semiquantitative
Steps Collation of existing coastal data Assessment of the possible impacts of a 1-m
sea level rise Implications of future development Possible responses to the problems caused by
sea level rise
Step 1: Collation of Existing Data
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 1-m Sea Level Rise
Four impacts are considered Increased storm flooding
Beach/bluff erosion
Wetland and mangrove inundation and loss
Salt water intrusion
Step 3: Implications of Future Developments
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
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
Biophysic-al Impact of Sea Level Rise
Socioeconomic impacts
Tourism Human Settlements
Agriculture Water Supply
Fisheries Financial Services
Human Health
Others?
Inundation
Erosion
Flooding
Salinization
Others?
Vulnerability Assessment
SusceptibilityResilience/Resistance
AutonomousAdaptation
Planned Adaptation
Natural Vulnerability
Biogeophysical Effects
Impact PotentialAbility to
Prevent or Cope
AutonomousAdaptation
PlannedAdaptation
Socio-EconomicVulnerability
Residual Impacts
AcceleratedSea-Level Rise
OtherClimatic and Non-Climatic
Stresses
Socio-Economic System
Natural System
BOUNDARYCONDITIONS
NATURAL SYSTEM
SENSITIVITY ADAPTIVE CAPACITY
SOCIOECONOMIC SYSTEM
SENSITIVITY ADAPTIVE CAPACITY
EXPOSURE
EXPOSURE
Future
Historic
The Coevolving Coastal System
Barriers to Conducting Vulnerability Assessments
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 socio-
political conditions
Controls on Coastal Position
littoral sedimentsupply (±ve)
sea-levelchange
antecedentphysiography
boundary conditions (external)
lower shorefacebackbarrier
uppershoreface
bypassingcr
oss-
shel
f
transportinlet
resuspension & inlet bypassing
fluvial-delta inlet bypassing
coastal tract
B
DC
A
inner-shelf sand
mid-shelf mud
marine sand wedge
lagoon basin mud
Beach Erosion
Bruun Rule
Bruun Rule (continued)
R = G(L/H)Swhere: H = B + h*
R = shoreline recession due to a sea-level rise S
h* = depth at the offshore boundary B = appropriate land elevation L = active profile width between boundaries G = inverse of the overfill ratio
Limitations of the Bruun Rule
Only describes one of the processes affecting sandy beaches
Indirect effect of mean sea level rise 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
Increase in flood levels due to rise in sea level
Increase in flood risk Increase in populations in coastal floodplain Adaptation
Increase in flood protection Management and planning in floodplain
Coastal Flood Plain
Global Incidence of Flooding No Sea Level Rise
0
10
20
30 P
eop
le F
lood
ed (
Mill
ion
s/yr
)
1990 2020s 2050s 2080sTime (years)
Vulnerable RegionsMid-estimate (45 cm) by the 2080s
C
A
C
B
PEO PLE AT RISK(m illio ns p e r re g io n)
> 50 m illio n
10 - 50 m illio n
< 10 m illio n
re g io n b o und a ry
vulne ra b le isla nd re g io n
Pa c ificO c e a nSM ALLISLAN D S
C a rib b e a n
Ind ia nO c e a nSM ALL ISLAN D S
C
B
A
Reference (1990)Land unavailable for arable Agriculture (% cell)
Low climate change High climate change
Impacts of Flooding on Arable Agriculture in 2050 – No Adaptation
0
20
40
60
Peo
ple
Flo
ode
d (M
illio
ns/y
r)
No Sea-Level Rise
Unmitigated Emissions
Kyoto Protocol
20% Emissions Reduction
30% Emissions Reduction
Global Impacts of Coastal Flooding in 2050 – Effects of Mitigation
People flooded (Millions/yr)
The Thames Barrier
Flood Methodology
Relative Sea-LevelRise Scenarios
Raised Flood Levels
Global Sea-levelRise Scenarios
Size of Flood Hazard Zones
People in theHazard Zone
Subsidence
Storm SurgeFlood Curves
Coastal Topography
PopulationDensity
Protection Status(1in 10, 1 in100, etc.)
Average AnnualPeople Flooded,
People to Respond
(“EXPOSURE”)
(“RISK”)
Relative Sea-LevelRise Scenarios
Raised Flood Levels
Global Sea-levelRise Scenarios
Size of Flood Hazard Zones
People in theHazard Zone
Subsidence
Storm SurgeFlood Curves
Coastal Topography
PopulationDensity
Protection Status(1in 10, 1 in100, etc.)
Average AnnualPeople Flooded,
People to Respond
(“EXPOSURE”)
(“RISK”)
Ecosystem Loss
Inundation and displacement of wetlands e.g., mangroves, saltmarsh, intertidal areas
Areas provide Flood protection Nursery areas for fisheries Important for nature conservation
Loss of valuable resources, tourism
KEY: mangroves, o saltmarsh, x coral reefs
Coastal Ecosystems at Risk
(a) no hard defenses (b) hard defenses
Sea Level Rise
Coastal Squeeze (of coastal wetlands)
Mangrove Swamp
Areas Most Vulnerable to Coastal Wetland Loss
Present day loss rate
High Climate Change
Low ClimateChange
Saltmarsh Losses to 2050
Wetland Loss Model Structure
Relative Rate of Sea Level
Rise Scenarios
Rate of Sea Level Rise Scenarios
Vertical Wetland
Response
Wetland Loss
Tidal Range
NoLoss
Coastal Geomorph
-ology
Migration Potential
Corrected wetland loss
Coastal Population
Density
Horizontal Migration Assessment
Wetland Vertical Response Model
RSLR* = RSLR/TR
where:RSLR = the rate of relative sea level rise
(meters/century)
TR = the mean tidal range on spring tides in meters
RSLR* > RSLR*crit loss
RSLR* ≤ RSLR*crit no loss
Planning Assessment
Ongoing investigation and formulation of policy Requires information on
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
The ProblemCliff Protection Has Local and Wider Effects
ErosionOften Exported Alongshore
Beach evolution
Defense degradation/upgrades
Socioeconomic changes
Sea level rise
Increased storminess
Changing impacts
Sediments
Changing loads
Coastal Flood Risk Exacerbated by Declining Sediment Input
Goals for Planning Assessment
For future climate and protection scenarios, explore interactions between cliff management and flood risk within sediment sub-cell (in Northeast Norfolk)
In particular, quantify Cliff retreat and associated impacts Longshore sediment supply/beach size Flood risk Integrated flood and erosion assessment
Climate Change,Sea-Level Rise
Scenarios
RegionalWave/Surge
Models
Protection,Socio-economic
Scenarios
SCAPERegional
Morphological Model
SCAPE GISData Storage
FloodRisk Analysis
(LISTFLOOD-FP)
Cliff ErosionAnalysis
Scenarios
IntegratedCell-scale
Assessment
Analysis OverallAssessment
Climate Change,Sea-Level Rise
Scenarios
RegionalWave/Surge
Models
Protection,Socio-economic
Scenarios
SCAPERegional
Morphological Model
SCAPE GISData Storage
FloodRisk Analysis
(LISTFLOOD-FP)
Cliff ErosionAnalysis
Scenarios
IntegratedCell-scale
Assessment
Analysis OverallAssessment
Method for Planning Assessment
Nearshore sandbank
Offshore sandbank
Bathymetry and Wave Modelling
TidesWaves
Wave transformation
Longshoresediment transport
Q3D shore shape
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n+1
Beach volume
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n
Beach volume
TidesWaves
Wave transformation
Longshoresediment transport
Q3D shore shape
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n+1
Beach volume
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n
Beach volume
TidesWaves
Wave transformation
Longshoresediment transport
Q3D shore shape
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n+1
Beach volume
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n
Beach volume
TidesWaves
Wave transformation
Longshoresediment transport
Q3D shore shape
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n+1
Beach volume
Inshore waves
Cross-shore erosion
Cross-shore shape
Cliff retreat
Section n
Beach volume
SystemMorphologicalModel
SCAPE Model of Cliff Retreat
-150 -100 -50 00
5
10
15
20
25
30
355 year stages
Recession distance
Dis
tanc
e al
ong
base
line,
km
H
B
M
T
O
C
S
0 0.5 1 1.5 2 2.50
5
10
15
20
25
30
35Average over 50 years
Recession rate (m/A)
H
B
M
T
O
C
S Sheringham
Cromer
OverstrandTrimmingham
Mundesley
Bacton
Happisburgh
Future PolicyMaintain Defenses, 6 mm/yr Sea Level Rise
-150 -100 -50 00
5
10
15
20
25
30
355 year stages
Recession distance
Dis
tanc
e al
ong
base
line,
km
H
B
M
T
O
C
S
0 0.5 1 1.5 2 2.50
5
10
15
20
25
30
35Average over 50 years
Recession rate (m/A)
H
B
M
T
O
C
S
Do NothingOpen Coast
Sheringham
Cromer
OverstrandTrimmingham
Mundesley
Bacton
Happisburgh
Future PolicyAbandon All Defenses, 6 mm/yr Sea Level Rise
-150 -100 -50 00
5
10
15
20
25
30
355 year stages
Recession distance
Dis
tance a
long b
aselin
e,
km
H
B
M
T
O
C
S
0 0.5 1 1.5 2 2.50
5
10
15
20
25
30
35Average over 50 years
Recession rate (m/A)
H
B
M
T
O
C
S
-150 -100 -50 00
5
10
15
20
25
30
355 year stages
Recession distance
Dis
tance a
long b
aselin
e,
km
H
B
M
T
O
C
S
0 0.5 1 1.5 2 2.50
5
10
15
20
25
30
35Average over 50 years
Recession rate (m/A)
H
B
M
T
O
C
S
Do NothingOpen Coast
Hold existing defenses
Abandon all defenses
Sheringham
Cromer
OverstrandTrimmingham
Mundesley
Bacton
Happisburgh
Policy ComparisonMaximum Retreat at Abandoned Defenses
Erosion Visualization Protection Abandoned (10 year time steps)
Conclusions
45 sea-level/wave/protection scenario combinations assessed
Used to assess implications for flood risk Data management, visualisation, and
stakeholder involvement used Further improvements to the overall method
are being developed
Models
DIVA: Dynamic and Interaction Vulnerability Assessment Project: DINAS-Coast
RegIS2 : Development of a metamodel tool for regional integrated climate change management
COSMO RamCo
Data Sources
IPCC Data Distribution Centre Sea level data
Permanent service for mean sea level GLOSS – Global Sea-Level Observing
System Remotely sensed data
Land Processes Distributed Active Archive Centre (NASA)
Shuttle radar topography mission
GLOSS Tide Gauges
GTOPO30Global Digital
Elevation Model
SRTM Data – Morocco and Gibraltar (vertically exaggerated)
Data Sources
Local observational data Sea level measurements Elevation/topography Wave recording Aerial photography Habitat mapping
Concluding Remarks
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
1A.86
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