Wwf5 131

20
Integated Urban Flood Risk Management Chris Zevenbergen, William Veerbeek – COST C22/UNESCO-IHE Srikantha Herath – UN University

Transcript of Wwf5 131

Page 1: Wwf5 131

Integated Urban Flood Risk Management

Chris Zevenbergen, William Veerbeek – COST C22/UNESCO-IHESrikantha Herath – UN University

Page 2: Wwf5 131
Page 3: Wwf5 131

Sheffield & Don

HannoverDrechtsteden

Lidköping

MARE partnership

Page 4: Wwf5 131
Page 5: Wwf5 131

Contents

• What is at stake ?• Options for the future• Conclusions and recommendations

Page 6: Wwf5 131

What is at stake ? (1)

• >75% flood damage in urban areas;

• Current policies (if any) are generally directed to reduce flood probabilities;

• Despite economic considerations decisions on flood risk management are driven by events;

• The protection level is not the result of an economic trade-off;

• Extreme events (e.g. overtopping) are not yet taken into account/systems are not designed for failure.

Page 7: Wwf5 131

What is at stake ? (2)

• Floods are on the rise (damage: 5% increaseannually)

• Number of big flood disasters are increasing

• Only 5 percent of new development ‘under way’in the world’s expanding cities is planned (UN, 2007).

• Spatial distributions by and large ignore floodrisk

Page 8: Wwf5 131

Need for change

• Increasing vulnerability and uncertainty• Increasing complexity (and dynamics)

Current practise:- Large (collective) protection systems- Local scale interventions & preparedness- Mixed strategies ?

Page 9: Wwf5 131

Towards action

Bringing ideas into action is about:– Risk perception and communication– Changing human behaviour– Learning from best practices and failure– Relationships

Page 10: Wwf5 131

Natural cause

Human cause

CatastropheCrisis

extreme weather events

major (devastating)

flooding

climate change

Extreme event vs disaster

Page 11: Wwf5 131

Natural cause

Human cause

CatastropheCrisis

extreme weather events

major (devastating)

flooding

climate change

Extreme event vs disaster

Disaster impacts are determined

by vulnerability that can be understood, managed and reduced.

Page 12: Wwf5 131

Urbanisation

Current paradigm:• buildings last forever and ‘site or urban

location is eternal’• planning practices based upon static

conditions of climate and building stock.

New paradigm:• cities are dynamic complex systems:

autonomeous/planned adaptation• change and variability are characterized by

uncertainty

Page 13: Wwf5 131

CC: uncertainty increases

• Variability increases:more extreme events• Future climate cannot be predicted on the basis

of past events: probability is dead!• No best solution• Opportunities for innovations• CC actual impacts vs ‘autonomous’ impacts (e.g.

city development) difficult to distinguish: impact of the first is likely much higher

• CC incentive to reform current practices

Page 14: Wwf5 131

Coping with increasing complexity and uncertainty:

Cultivating/enhancing resilienceCultivating/enhancing resilience::•• Utilising Utilising reversible, robust, adaptable and diverse responsesreversible, robust, adaptable and diverse responses

(structural some non(structural some non--structural options in a portfolio)structural options in a portfolio)• Multi-sectoral (all parties with flood risk and spatial planning

responsibilities)/linking organizations and institutions across scales• Long-term perspective •• Building capacityBuilding capacity in people and systems (hard and soft)in people and systems (hard and soft)•• Promoting Promoting active learningactive learning through engagementthrough engagement• Learning by doing in demonstration projects• Seizing window of opportunity (e.g. renewal projects)•• Identifying and supporting Identifying and supporting championschampions• …..

* COST C22: CAIWA conference 2007

Page 15: Wwf5 131

synergies/short term benefits

Page 16: Wwf5 131

Building resilience measures in Hamburg

Page 17: Wwf5 131
Page 18: Wwf5 131

Pilot Dordrecht (Netherlands)

Page 19: Wwf5 131

To successfully manage future floods itrequires:– an understanding of what responses could be

used/are appropiate (much technologyalready available).

– the political will and infrastructure to deliver onthese ideas.

– engagement of the public

Page 20: Wwf5 131

Conclusions & recommendations

• CC provides an opportunity to rethink and adoptnew approaches

• Impact of extreme events can be managed• Focus on impact reduction requires strong

engagement of the public• Experimentation and learning• Need to catalyse action in cities around the

world through dissimination of knowledge, demonstration projects, from learning networksand high profile events.

• Flood Resilience Centre