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TRANSCRIPT
Integated Urban Flood Risk Management
Chris Zevenbergen, William Veerbeek – COST C22/UNESCO-IHESrikantha Herath – UN University
Sheffield & Don
HannoverDrechtsteden
Lidköping
MARE partnership
Contents
• What is at stake ?• Options for the future• Conclusions and recommendations
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.
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
Need for change
• Increasing vulnerability and uncertainty• Increasing complexity (and dynamics)
Current practise:- Large (collective) protection systems- Local scale interventions & preparedness- Mixed strategies ?
Towards action
Bringing ideas into action is about:– Risk perception and communication– Changing human behaviour– Learning from best practices and failure– Relationships
Natural cause
Human cause
CatastropheCrisis
extreme weather events
major (devastating)
flooding
climate change
Extreme event vs disaster
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.
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
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
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
synergies/short term benefits
Building resilience measures in Hamburg
Pilot Dordrecht (Netherlands)
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
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