Yates Michelin - Littoral 2010 (Education Centre)

8/8/2019 Yates Michelin - Littoral 2010 (Education Centre)

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Climate Change impacts,

adaptation, and associated costs

for coastal risks in France

G. Le Cozannet1, N. Lentre1, M. Yates Michelin1, P. Nacass2, B. Colas3,

C. Perherin4, C. Peinturier5, C. Vanroye6, C. Hajji7, B. Poupat3,

C. Azzam8, J. Chemitte7, and F. Pons9

1 BRGM, 2 Mto-France, 3 MEEDDM/SGDD/SoES, 4 CETMEF, 5 MEEDDM/CGDD/SEEI,6 DREAL/LR, 7 MRN, 8MEEDDM/DGPR/BRM, 9 CETE Mditerrane


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Context: application of the French Climate Plan (2006)

> 2

Natural Risks, Insurance, and Adaptation to Climate Change (RNACC)led by the MEEDM/DGPR/SRNH (Ministry of Ecology, Energy, Sustainable Development and Seas/Directorate General for

Risk Prevention/Service des risques naturels et hydrauliques)

Objective: initiate an evaluation of potential damages and possible mitigation strategiesto limit the cost of impacts

An interministerial working group, Climate change impacts, adaptation, and

associated costs for coastal risks in France , was created to address this objective.

Within which, an oversight committee was:

responsible for the methodological guidelines

guaranteed the homogeneity of the assessment methods

and 7 sectoral groups were created, one of which is:

Sub working groups:

- Swelling and shrinking of clays

- Lanslides

- Floods

- Coastal risks

Estimate costs of damages caused by

coastal erosion and inundation, and

identify what is specifically caused by

climate change


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RNACC Project: Coastal Risks

> Currently, 25% of the French coastlineis eroding

> Vulnerability to coastal inundation hasbeen highlighted by the impacts of

several severe storms: Lothar in 1999 and Xynthia in 2010 along the

Atlantic coast

1982, 1997, and 2003 storms on the Mediterraneancoast

> Climate change impacts will exacerbateexisting coastal erosion and inundation

hazards in the 21st century (Nicholls et

al., 2007)

> 3

Damage to port structures (le de R, port de La

Flotte). Source: Pedreros et al. (2010)

Inundation during Xynthia, March 2010.

Source: Rgis Duvigneau


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Coastal Risks Methodology

> 4

Coastal inundation and

erosion hazards in 2100

Climate change

hypothesisCurrent demographic

and economic statistics

in coastal areas

Evaluation of potential impacts to people,

residences, and public and private assets in 2100

Recommendations

for adaptation

Estimates of

associated costs


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Methodology applied in Languedoc-Roussillon

region in France

> 5

> 215 km of FrenchMediterranean coastline

between the border with

Spain and the Rhne

Delta, characterized by:

Hard rock cliffs with pocket

beaches in the southern

portion

Sandy beaches separated

by three rocky outcrops

Coastal lagoons separated

from the MediterraneanSea by lidos, or narrow

strips of beach with low-

lying dunes

Languedoc-Roussillon


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Evaluation of potential climate change impacts

> Potential climate change impacts Sea level rise

Storm regime

Storm surges

Wave climate

Precipitation

> 6

Climate change

hypothesis

Le Havre, France, December 2007

Source: Charlotte Grimbert

La Faute-sur-Mer and Aguillon, France,

February 2010


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> Potential climate change impacts Sea level rise increase in sea level rise (Meehl et al., 2007;

Rahmstorf, 2007; Grinsted et al., 2009; Ullman et

al., 2007; EUROSION, 2004; MICORE, 2009)

Storm regimes regional climate models have not shown

Storm surges significant changes (Dqu et al., 2003; Ullman,

Wave climate 2008 ; Lionello et al., 2008; MICORE, 2009)

Precipitation potential decrease in total precipitation

potential increase in number of days with morethan 10mm of precipitation (IMFREX, 2002)

> 7

?

Climate change

hypothesis


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> Potential climate change impacts Sea level rise increase in sea level rise (Meehl et al., 2007;

Rahmstorf, 2007; Grinsted et al., 2009; Ullman et

al., 2007; EUROSION, 2004; MICORE, 2009)

> 8

Scenario adopted : 1 m sea level rise in 2100

other climate change impacts are unable to be quantified

and are not taken into account in this study

Climate change

hypothesis


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Coastal erosion hazard zones

> Current trends in Languedoc-Roussillon: Decrease in supply of large-grained sediments

Increase in shoreline erosion

> Future trends in Languedoc-Roussillon: Uncertain, but likely to show at least a continuation of

current trends

Landward migration of lidos and breaching during stormevents (Paskoff, 2001)



Photo from 2003, Messina (2004)

Paskoff, 2001

Current situation

In 2100, with adequate sediment supplies

In 2100, with a depletion of sediment supplies

Erosion hypothesis:

partial opening of lidos

and erosion of sandy

coastline, estimated

with a 500m buffer zone

landward of the current

shoreline


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Coastal inundation hazard zones

10-year return

period event

100-year return

period event

10-year return

period event

100-year returnperiod event

Sea level

rise

In 2100 with 1 m of sea level rise

TODAY




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Hazard Evolution

Hazard

Effect of

climate

change

Type TimescaleReversibility

of effects

Proposed estimation of the

impact zone

Erosion aggravation continuousintra-annual

to multiannualirreversible

a buffer zone of 500 m inlandof erodible coastal zones

Permanentsubmersion

creation of anew hazard

continuousmultiannual to

decadalirreversible

the zone from 0 to +1 melevation

Temporarysubmersion

aggravationdis-

continuousa few hours

to a few daysreversible

the zone between +1 and +3 melevation

Characteristics of hazards considered in this study,

adapted from Garcin et al. (2009)




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Exposure of people and residences to

coastal hazards

Current demographic and

economic statistics in coastal areas

Reconstructed population density in the zones with an

elevation of less than 5m above sea level in

Languedoc-Roussillon (Source : CGDD SOeS, IGN)

Population density

500m-wide buffer zone:exposed to erosion in 2100

Below 1m NGF:exposed to permanent

inundation in 2100

Between +1m and +2m NGF:exposed to temporary inundation by

storms with a 10-year return period

Between +2m and +3m NGF:exposed to temporary inundation bystorms with a 100-year return period

4 zones affected bycoastal erosion and

inundation hazards


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Potential impacts to people and

residences in 2100

Evaluation of potential impacts to

people, residences, and public and

private assets in 2100

Water

Wetlands

Open spaces (with little vegetation)

Low-lying vegetation

Forests

Prairies and heterogeneous agriculture

Permanent agriculture

Arable landArtificial green spaces (non-agricultural)

Industrial zones, landfills, construction

Urban zones

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Surfaces en eau

Zones humides

Espaces avec peu de vgtation

Milieux vgtation arbustive et/ou herbace

Forts

Prairies et zones agricoles htrognes

Cultures permanentes

Terres arables

Espaces verts artificialiss, non agricoles

Zones indus., rseaux, dcharges et chantiers

Zones urbanises

As the distance from the

coast increases, thepercentage of urban

zones decreases(i.e. population, residences, public

and private assets, etc.)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Surf

cs

u

Zones

umi

es

s

ces

ec

eu

e t

tion

Milieux t

tion

r usti eet/ou

er

c e

For ts

r

iries et zones

ricoles

t rognes

ultures

ermanentes

Terres arables

s

aces erts artificialis s, nonagricoles

Zones indus., r seaux, dc

arges et c

antiers

Zones urbanises

Distance from t e s oreline Source : UE, SOeS, CORINE Land Cover 2000, Observatoire du littoral


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Potential impacts to people and

residences in 2100 (Rsultats CGDD/SoeS)




Hazard

In 2100

Irreversible

permanent inundation

or erosion hazard

Temporary inundation

caused by a 10-year return

period storm


caused by a 100-year

return period storm

Population 80,000 people 20,00 - 60,000 people 20,000 people

Residences 140,000 residences 40,000 - 100,000 residences 20,000 - 40,000 residences

Below 1m NGF:

exposed topermanent

inundation in 2100

OR

Between +1m and

+2m NGF:

exposed to temporaryinundation by stormswith a 10-year return

period

Between +2m and

+3m NGF:


period

500m-wide

buffer zone:exposed to erosion in

2100


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Potential impacts to public and private

assests in 2100

Distribution of public and private assets:- Artisans, merchants, and service providers 53%

- Agricultural enterprises 17%

- Industries 16%

- Public establishments 14%

Current demographic and

economic statistics in coastal areas


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Potential impacts to public and private

assests in 2100 (Rsultats MRN)




Below 1m NGF:

exposed topermanent

inundation in 2100

OR

Between +1m and

+2m NGF:


period

Between +2m and

+3m NGF:


period

Hazard

In 2100

Irreversible permanent

inundation or erosion

hazard


caused by a 10-year

return period storm


caused by a 100-year

return period storm

Total number ofestablishments 10,000 establishments 3,000 9,000establishments 6,000 12,000establishments

Number of

employees

impacted

26,000 employees8,000 - 25,000

employees

16,000 33,000

employees

500m-wide

buffer zone:exposed to erosion in

2100


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Associated costs Estimates ofassociated costs

Estimations of annual and

cumulative costs of coastal

risks caused by climate change

Cost of potential

damages to

residences

Cost of direct,

tangible damages

(estimate)

Cost of direct and

indirect, tangible

damages (estimate)

Coastal erosion and permanent

inundation

(only destroyed buildings)

150 Million / year 300 Million / year 600 Million / year

Coastal erosion and permanent

inundation

(buildings and land loss)

350 Million / year 700 Million / year 1400 Million / year

Temporary inundation 15 Million / year 30 Million / year 60 Million / year

Examples of

damages Tangible Intangible

DirectDestruction of an economic asset(e.g.. buildings, public transportation orcommunication infrastructure, etc.)

Loss of human life, or loss of a naturalspace

IndirectLoss of use(e.g. losses due to non-use of propertydestroyed or damaged by a catastrophe) .

Increase in the vulnerability of thepopulation affected by a crisis


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Adaptation recommendations

> Enhance knowledge, particularly with regular data collection atrepresentative study sites to improve long term coastal evolution modeling

> Share knowledge with the public to accurately communicate risk perception

> Development of planning progams that take into account climate change(e.g. government risk prevention plans, inundation zone maps, local urban

planning documents, land use planning management)

> Envisage protection, relocation, and adaptation strategies at all levels ofmanagement (local, regional, and national)

> Adopting without regrets adaptation measures addressing todays risksas a first step toward addressing future coastal risks

Recommendations

for adaptation

Insufficient data for robust cost-benefit analyses

Increased risk of over-adaptation (high cost of adaptation) and

under-adaptation (high cost of damages), both with strong

economic consequences (Hallegatte et al., 2006)


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Limitations of this study: chain of errors

Climate change

Local sea level rise

Long term coastal evolution

(erosion/accretion)

Ability to accurately identify

affected zones

Accurate population andland use statistics

Ability to estimate

associated costs

A continuation of this

study investigates these

3 sources of error, to

quantify and minimize thelargest errors to improve

the RNACC method.


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Conclusions

> Costs of current risks are negligible in comparison to the

cost of future risks

> Costs of potential damages due to erosion and permanentinundation are larger than those due to temporaryinundation

> Emphasizes the importance of developing long-term coastalmanagement plans at all levels of governance

> At a minimum, it is necessary to reduce short-term risks asa first step toward reducing long-term risks

> Highlights a number of limitations and sources of errors inclimate change impact studies due to limited dataavailability (study in progress to quantify and reduce theseerrors)


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Thank you for your attention!

Study financed by:

French Ministry of Ecology, Energy, Sustainable

Development, and the Sea (MEEDDM)

and

BRGM Research Division

Photo: Yann Krien


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Quality of Topographic Data

Datasets available in Languedoc-

Roussillon include: DTM of IGN, with 50m horizontal

resolution and 1m vertical steps

DTM of Intermap, with 5m horizontal

resolution

DTM - Lidar data, with 2m horizontal

resolution


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Limitations of this study: chain of errors

Climate change

Local sea level rise

Long term coastal evolution

(erosion/accretion)

Ability to accurately identify

affected zones

Accurate population andland use statistics

Ability to estimate

associated costs

Sea level rise scenarios:0, 0.5, 1, and 1.5m

Long term coastal evolution: The Bruun Rule

Extrapolation of historical trends

Extrapolation of historical trends with anajustment based on the Bruun Rule

A fixed erosion rate (i.e. 500m in this study)

Scientific expertise

Quality of available topographic data:

50m horizontal resolution, 1m vertical steps5m horizontal resolution

2m horizontal resolution


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Sea Level Rise Scenarios

> Total land area affected by erosion, following the Bruun Rule and

four different sea level rise scenarios: Sea level rise 0m = 0 km2

Sea level rise 0.5m = 1.26 km2

Sea level rise 1m = 2.52 km2

Sea level rise 1.5m = 3.78 km2

Erosion caused by

sea level rise


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Long Term Coastal Evolution

> Land area affected by erosion following four different methods of

assessment: Fixed buffer zone (RNACC project) = 14.29 km2

Bruun Rule = 2.52 km2

Extrapolation of historical trends = 1.86 km2 (+0.65 km2)*

Extrapolation of historical trends, = 3.22 km2 (+0.21 km2)*

adjusted with Bruun Rule * land area gained by accretion


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Quality of Topographic Data

Donnes

altimtriquesErosion*

Submersion

permanente**

Submersion

temporaire,

vnementdcennale**

Submersion

temporaire,

vnementcentennale**

MNT de lIGN 1.2 km2 8.5(2.3) km2 4.0(3.2) km2 3.9 (3.7) km2

MNT dIntermap 2.6 km2 11.0(5.1) km2 3.3 (3.2) km2 1.1 (1.1) km2

MNT du Lidar 0.7 km2 4.3 (3.3) km2 3.5(3.3) km2 1.4 (1.4) km2

Yates Michelin - Littoral 2010 (Education Centre)

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