Foresight Flood and Coastal Defence Project Government Office for Science Department for Innovation, Universities and Skills Overview by: Colin Thorne

Foresight Flood and Coastal Foresight Flood and Coastal Defence ProjectDefence Project

Government Office for ScienceDepartment for Innovation, Universities and Skills

Overview by:

Colin ThorneUniversity of Nottingham

[email protected]

on behalf of the Foresight Team

mailto:[email protected]

Overview

• Project aims

• Methodology

• River, Coastal and Intra-urban Drivers

• Predicting Future Risks (baseline case)

• Responses: Structural and nonstructural measures

• Costs and Affordability of Responses

• Final Messages and Further Information

June 2007

July 2007

Foresight Project Aims

• Produce a long-term vision for future flood

and coastal risks and their management in

the UK.

• Cover all aspects of flood & coastal

erosion risk for the whole UK, looking 30 –

100 years ahead.

• Provide a reliable evidence-base for

decision makers, using expert knowledge

and high level flood and erosion risk

analyses.

• Supply the underpinning science for

national-level policy making.

Methodology

The flooding system

Foresight Futures 2020

Foresight Futures 2020 + UKCIP2002 climate change scenarios

Medium-low emissions

High emissionsand

Low emissions

Medium-high emissions

Low emissions

• .

System state variablesPathways

urban surfacesfields, drains

channelsflood storage

flood defences

floodplains

Receptorscommunities

homesindustries

Infrastructureresources

ecosystems

Sourcesrainfall

sea levelstorm surgeswave

heights

etc.

RiskProbability x

consequences(economic, risk to life, social, natural environment etc)

System analysis

DriversProcesses that change the state of the

systemChange in risk

ResponsesInterventions that change the state of the

system

Change in risk

Flood Risk Drivers:

Deep Description and Qualitative Analysis

Future Flood Risks:

Drivers of River and Coastal Flooding

Drivers of Flood and Coastal Erosion Risk

“… any phenomenon that changes the state of the flooding system…”

Drivers of fluvial and coastal flooding

Driver group Driver SPR classification

Precipitation Source Climate change

Temperature Source

Urbanisation Pathway

Rural land management Pathway

Catchment runoff

Agricultural impacts Receptor

Environmental regulation Pathway

River morphology and sediment supply

Pathway

Fluvial Systems and Processes

River vegetation and conveyance Pathway

Waves Source

Surges Source

Relative sea level rise Source

Coastal processes

Coastal morphology and sediment supply Pathway

Stakeholder behaviour Pathway Human behaviour

Public attitudes and expectations Receptor

Buildings and contents Receptor

Urban impacts Receptor

Infrastructure impacts Receptor

Social impacts Receptor

Socio- economics

Science, engineering and technology Receptor

Baseline ranking of river and coastal drivers• Socio-economic drivers

• Coastal drivers

• Precipitation

• Big scenario differences

Major uncertainties:

• Sea level rise

• Coastal morphology

• Surges

• Precipitation

• Stakeholder behaviour

• Public Attitudes+Expectations

Future Flood Risks – Drivers of intra-urban flooding

• The catchment and coastal risk analysis treated urban areas as receptor

units containing people, property and infrastructure.

• Another set of sources and flood pathways at local scales operates within urban areas due to extremely intense rainfall and/or congested drainage (sewer) flooding - termed ‘intra-urban flooding’.

Drivers in urban areas

Plus:• Stakeholder behaviour• Urban planning policy

Ranking of intra-urban scale drivers• Social impacts

• Asset deterioration

• Intense Precipitation

• Environmental management and regulation

Quantitative Analysis of Future Flood and Coastal Erosion Risks

(Baseline Case)

Modeling: National quantitative risk analysis:

RiskAssessmentforStrategicPlanning

Data used:Rivers and coastlinesFloodplain mappingStandard of protection Condition of defencesAddresses of all properties/people at riskFlood damage by depthSocial vulnerabilityAgricultural land grade

Calculating future flood riskPathway

(e.g. beach, raised/non-raiseddefence and floodplain)

Source (River or sea)

Receptor(e.g. people and property)

Pathway(e.g. beach, raised/non-raised

defence and floodplain)

























Dominant valley classcoastallowland (intermediate / shallow valley slopes)upland (steep valley slopesno defences

Drawing numberJob number

Date

Dominant Valley Class

Revision

Foresight - Future Flood Risks

June 2003 1.01

CDS 0438

0 40 8020Kilometres ±

This map is reproduced from Ordnance Survey materialwith the permission of Ordnance Survey on behalf ofthe controller of Her Majesty's Stationary Office.(c) Crown Copyright. Unauthorised reproductioninfringes Crown Copyright and may lead to prosecutionor civil proceedings.Department of Trade and Industry. 100037208. 2003.

Dominant Floodplain Class (2002)

Wales

Midlands

East Anglia

North-east

South-west

Thames

North-west

South-east

Dominant valley classcoastallowland (intermediate / shallow valley slopes)upland (steep valley slopesno defences

Drawing numberJob number

Date

Dominant Valley Class

Revision

Foresight - Future Flood Risks

June 2003 1.01

CDS 0438

0 40 8020Kilometres ±

This map is reproduced from Ordnance Survey materialwith the permission of Ordnance Survey on behalf ofthe controller of Her Majesty's Stationary Office.(c) Crown Copyright. Unauthorised reproductioninfringes Crown Copyright and may lead to prosecutionor civil proceedings.Department of Trade and Industry. 100037208. 2003.

Flood Risk Predictions for 2050 and 2080 Foresight

Future Flood Risks

All Scenarios: Comparative RiskExpected Annual

Probability of Flooding

Present Day 2002

Outside IFP

HighMediumLowNegligible

Probability of Inundation to a depthgreater than 0.0m

N0 50 100 Kilometers

Job: WPSFSG

Note: Comparisons represent thedifference between Present Day 2002results and Foresight Future Scenarios

Very High

Negligible Increase

Low

MediumHigh

Low Increase

Medium IncreaseHigh Increase

Decrease

Outside IFP

Negligible Increase

Low

MediumHigh

Low Increase

Medium IncreaseHigh Increase

Decrease

Outside IFP

Negligible Increase

Low

Medium

High

Low Increase

Medium Increase

High Increase

Decrease

Outside IFP

Negligible Increase

Low

Medium

High

Low Increase

Medium Increase

High Increase

Decrease

Outside IFP

Negligible Increase

Low

Medium

High

Low Increase

Medium Increase

High Increase

Decrease

Outside IFP

World Markets 2080's World Markets 2050's

Local Stewardship 2080's National Enterprise 2080's Global Responsibility 2080's

Present Day 2002

Date: July 2003

Expected annual damages: £ millions (currently ~ £1billion)

Baseline Conclusions: unless we act:-

• Future flooding and coastal erosion are very serious threats to the UK.

• They represent a major challenge to government and society.

• Combining the World Markets and Low emissions scenarios reduces future expected annual economic damages by only ~25%.

Responses

Options for managing future flood and coastal erosion risks

sustainably

80 individual responses

80 individual responses

Organised into 25 response groups

Organised into 25 response groups

Potential Responses

And 5 response themes

• Reducing urban runoff

• Reducing rural runoff

• Managing flood events

• Managing flood losses

• Engineering and large scale re-alignment or abandonment

And 5 response themes

• Reducing urban runoff

• Reducing rural runoff

• Managing flood events

• Managing flood losses

• Engineering and large scale re-alignment or abandonment

Deep Response Descriptions

• Definition, Function and Efficacy• Governance• Sustainability

Environm ental Quality

Social Justice

Robus tness

Pre cau tion

Flood r isk

Cost Effectivene ss

— neutral

++

--

• Costs• Interactions• Case example• Emerging issues• Uncertainty

• Potential for implementation under each of the four Foresight future scenarios

Responses with the most potential for risk reductions

Responses Groups ranked by potential risk reduction in the 2080sRank World

MarketsNational

EnterpriseLocal

StewardshipGlobal

Sustainability1 River

DefencesRiver

DefencesLand Use Planningand Management

Land Use Planningand Management

2 CoastalDefences

CoastalDefences

Flood ProofingBuildings

Catchment-WideStorage

3 Flood ProofingBuildings

Reduce CoastalEnergy

Individual DamageAvoidance

RiverDefences

4 Reduce CoastalEnergy

Realign CoastalDefences

RiverDefences

CoastalDefences

5 MorphologicalCoastal Protection

MorphologicalCoastal Protection



6 Realign CoastalDefences

Coastal DefenceAbandonment

Pre-eventMeasures

RuralConveyance

7 Real-time EventManagement


Real-time EventManagement


8 RiverConveyance

RiverConveyance

Engineered FloodStorage


9 Individual DamageAvoidance


RuralConveyance


10 Pre-eventMeasures

Land Use Planningand Management

RiverConveyance


11 Engineered FloodStorage


RuralInfiltration


12 Land Use Planningand Management


Manage UrbanRunoff

Pre-eventMeasures

13 Manage UrbanRunoff

Pre-eventMeasures

Flood WaterTransfer


14 Flood WaterTransfer

RuralConveyance

CoastalDefences

RiverConveyance

15 Catchment-WideStorage

RuralInfiltration


RuralInfiltration

16 RuralConveyance



Manage UrbanRunoff

17 RuralInfiltration

Manage UrbanRunoff


Flood WaterTransfer

18 Flood WaterTransfer

Coastal DefenceAbandonment

Legend

Colourcode

Interpretation

Major reduction in flood risk ( S < 0.7)Marked reduction in flood risk (0.7 < S < 0.9)Minor reduction in flood risk (0.9 < S < 1.0)Ineffective ( S = 1)Likely to Increase flood risk ( S > 1.0)

• Structural: Important, but need to rethink Coastal Defences

• Non-structural: We can manage down flood & erosion losses

How much will it cost – are responses affordable?

• The cost of implementing engineering- based structural

approach alone to achieve the indicative standard of defence

in the 2080s is ~ £52 billion

• The cost of using structural defences as part of an integrated

portfolio of structural and non-structural responses is ~ £22

billion

Delivering the message

• First level – Briefing notes for elected officials

• Second level – Technical reports, papers and book

• Third level – Working documents and project record

• Fourth level – Video game for practitioners and students

Flood Ranger Video Game

Final Messages

• Future flood and coastal erosion risks are likely to increase due to climate, economic, social and planning drivers if we go on as we are.

• We can make it easier or harder for ourselves by our actions on global emissions and governance.

• There are feasible and sustainable responses that can hold risk at present day levels affordably - if implemented through Integrated Flood Risk Management.

• But we must act now in developing new policies to allow non-structural measures to be effective in time.

Closing Statement

Have confidence: UK Foresight proves it is possible to develop a long-term vision for IFRM.

Politicians will listen and act provided that your messages are clear and are properly supported by the best science and engineering analyses available.

Further Information

Flood Foresight:

www.foresight.gov.uk

• Follow links for flood and coastal defence

UK Research Consortium on Flood Risk Management:

www.floodrisk.org.uk

http://www.foresight.gov.uk/

http://www.floodrisk.org.uk/

Over to the Break-out Groups!

Colin ThorneUniversity of Nottingham

[email protected]



Documents

Foresight Flood and Coastal Defence Project Government Office for Science Department for Innovation, Universities and Skills Overview by: Colin Thorne