reducing vulnerability of urban lowland areas
TRANSCRIPT
Acknowledgements
The concept of vulnerability
• Why is it important: • Objective of society to become less vulnerable to
environmental variation such as variation of water resources and variation of water levels
• Future variation is uncertain
The concept of vulnerability
• A common definition of vulnerability:
‘sensitivity of a system for exposure to shocks, stresses and disturbances, or the degree to which a system is susceptible to adverse effects’ (Leurs, 2003; Turner et al., 2003; IPCC, 2001; Schiller et al, 2001)
• Disturbances or can be both exogenous or endogenous.(eg. A drought can be caused by low precipitation, bad water management or both)
The concept of vulnerability
• Possible responses towards environmental variation that reduce vulnerability: • Reduce (or control!) environmental variation
Building a threshold, example:• Reduce damage if this threshold is exceeded
Develop ability to cope with impacts• Recover quickly and effectively after damage has
occurred Develop ability to recover
• If future variation is uncertain and potential impacts are large Develop ability to adapt
Type Time orientation
Responsibility
Threshold Capacity
Damage
prevention
Past Clear
Coping Capacity
Damage
reduction
Instant Not clear
Recovery Capacity
Damage
reaction
Instant/
future
Not clear
Adaptive Capacity
Damage
anticipation
Future Undefined
The concept of vulnerability
Flood control
Flood control
Water
supply
Water
supply
Threshold Capacity
Higher dikes Increase river capacity
Increased reservoir capacity
More efficient supply infra
Coping Capacity
Improve risk perception
Emergency plan & warning
Backup supply facilities
Individual storage
Recovery Capacity
Disaster funds & Insurance
Recovery plans
Multi-source water supply
Disaster funds & Insurance
Adaptive Capacity
Flood proof & flexible urbanization
Small scale pilot projects
Flexible portfolio of sources
Small scale pilot projects
The concept of vulnerability
The concept of vulnerability
• Vulnerability of a system is difficult to assess because components of vulnerability are strongly interrelated.
• Example: Increased flood defense (threshold capacity) leads to increased urbanization and a decreased flood risk perception (coping capacity).
Dutch vulnerability lock in
Coping
Capacity
Adaptive
Capacity
Threshol
d
Capacity
Recovery
Capacity
Urbanization
Increased flood risk
Higher dikes
& pumpingcapacity
UrbanizationVulnerable delta
Land subsidenceIncreased vulnerability
Lock-in
Adaptive capacity
Concluding remarks
• If we accept that we cannot completely control environmental variation, developing threshold capacity only will make us vulnerable for rarely occurring, high impact flood events and drought events
• 4 components of vulnerability framework may assist in developing more comprehensive strategies
• Governance mechanisms to successfully introduce the 4 capacities in everyday practice of citizens and professionals are still lacking
Questions
Literature:• Water Science and
Technology, Vol 56 No 4, pp 165-173
• Natural Hazards, 2008• Urban Water in Japan,
Taylor& Francis Urban Water Series vol 11