Evacuation in case of large scale flooding in The Netherlands
3 March 2010
Matthijs Kok, Bas Kolen
HKV consultants
www.hkv.nl
Topics
• Introduction
• Flood policy in The Netherlands
• Definitions of evacuation
• Evacuation scenarios
• Discussion about model assumptions
• Conclusion and questions
HKV - Water and Safety
• Private Company, 65 people
• Applied research and advise in:
• Risk analyses
• Emergency management
• GIS and IT
• Water systems
• 4 offices (Lelystad, Delft, Aken (GER), Jakarta (Asia)
• 15% of budget for R&D
• 15% target for projects outside The Netherlands
• Main client: Dutch Authorities (National en regional level)
Flood policy in The Netherlands
1953: “This may never happen again” Focus on prevention
1. International high safety level
2. Low probability, mass impact
1. P
rev
en
tion
2. S
pa
tial P
lan
nin
g
3. E
me
rge
ncy
Ma
n
F lo o d P r o t e c t io n A c t
I m p l i c i t v a lu e s3. Policy (since 2008
National Water Plan):
• Prevention (law)
• Spatial planning
• Emergency management (planning, forecasting)
Flood protection in The Netherlands
1. Coast and river
2. Canals
3. Rainfall
Flood protection in The Netherlands
• Frequency flood (river, sea) 1/1250 – 1/10.000 year (protection act)
• Frequency threat is more1/10 (alarm)1/100-500 year (evacuation – estimated)
• Early warning: Flood Forecasting Centers
• Bottom up alarm procedure
• River: 2-3 days
• Sea: 6h – 1 day
• New (more) mid term models: Top down procedureNational Commission Flooding (LCO)
• Disaster Management Planning by National and regional planning (safety region, water board, etc)
Possible scenarios
1. Size (large, small)
2. Forecast (lead time: early, late)
3. Threatened area is sum all possible scenario’s, threatened area is related to window of forecast
‘Safety Standards’ Katwijk ‘Safety Standards’ Rotterdam
Worst Credible Flood ‘upper limit’
4300 square km120 Mld Euro 10.000 casualties
•movie
Organisation crisismanagement
MPT/IPTNCCC
RCC
PCC
MCC
NCC NOCC
The Hague Driebergen
Evacuation: the organization of and the movement to a (relatively) safe place in case of a threat
• Varying destination and moment of onset, types are:
1. Preventive evacuation: Movement before start of disaster to a place outside threatened area
2. Shelter (Horizontal and vertical evacuation): Movement before start of disaster to a shelter of safe haven inside threatened area
3. Shelter in place (only vertical evacuation): Move to upper floors
4. Acute evacuation: Movement after start of disaster before being exposed
5. Rescue:Movement supported by first responders after being exposed
6. Escape: Movement by self reliance after being exposed
Evacuation in The Netherlands
Study ‘National Security, capability based planning’:
• 4 different strategies of evacuation
• 4 types of traffic management
1. Reference
2. Nearest exit
3. Optimal use of exits
4. Flow off areas
• Risk zoning in threatened area based on realistic forecasting (all possible floods)
National Security
Traffic Management / Route Choice
Model assumptions
• Evacuation of threatened area
• People at home at start and are self reliant
• +/- 10% not self supporting
• Communication (Evacuation routes are known, 20% will not ‘listen’)
• Behavior (traffic, departure)
• Enough resources (limitations are the next step)
• Outflow of area
• Road management (worst cases: nearest exit, reference, best cases: optimal use of exits and flow of (user defined))
• Movie
Results: Bottle necks
5 uur 10 uur
15 uur
1 dag
1,5 dag 2 dagen
Aantal voertuigen Per strekkende kilometer
Results: Extern bottle necks
Bottle necks outside ‘evacuation zone’ when also considering outflow
48 hours after start
Movie: National concept evacuation (best case), preventive evacuation
Results after 33 hours
17072%
70072%
14080%
320033%
10080%
Advance national traffic management after 33 hours:
- Evacuation population x 1000
- % success in 33 hours (available time during Floodex)
Results
• More then 72 hours is needed for total preventive evacuation (strategy 1) for the Western Coast
• More then 24 hours is needed for only evacuating self supporting (strategy 4) for the Western Coast
• Preventive evacuation of entire coastal area in 48 hours (that includes 24 hour of severe storm) is not possible
• Vertical evacuation, shelter in place (and support self reliance) is necessary to consider
• Advanced traffic management and strategies could work, but has to be implemented, prepared and communicated in time
Advanced traffic management
Total Preventive evacuation (80%)
Minimall preventive evacuation (30%)
South & North Holland >72 24
Zealand 27 18
No extra traffic management
Total Preventive evacuation (80%)
Minimall preventive evacuation (30%)
South & North Holland >72 >72
Zealand 35 18
Discussion
• Available Time
• Behavior of people
• Traffic management / Route choice
• Expected success of preventive evacuation (taking all possible scenarios into account)
Available time
Extreme Wind
T+..T+1T0T-1T-2T-3T-4T-5T-10..6
Possib
le
Dik
e
Bre
ach
Detection and sense making
Early
Detection
Late
Detection
- Uncertainty in forecasts (nature)
- Uncertainty in interpretation of forecasts by decision makers and willingness to take action
Available time
Tijd voor hoog water (dagen)
4 3 2 1 0
Friesland & Groningen
0,05 0,2 0,5 0,15 0,1
Noord-Holland Zuid-Holland
0,05 0,1 0,3 0,45 0,1
Zeeuwse en ZH-eilanden
0 0 0,5 0,4 0,1
Zeeuws Vlaanderen
0 0 0,5 0,4 0,1
Meren 0 0 0,4 0,4 0,2
Rivieren (Rijn) 0 0,2 0,5 0,2 0,1
Rivieren (Maas) 0 0 0,5 0,4 0,1
Benedenrivieren-gebied
0 0 0,2 0,5 0,3
Coast
Tijd voor hoog water (dagen)
4 3 2 1 0
Friesland & Groningen
0,05 0,2 0,5 0,15 0,1
Noord-Holland Zuid-Holland
0,05 0,1 0,3 0,45 0,1
Zeeuwse en ZH-eilanden
0 0 0,5 0,4 0,1
Zeeuws Vlaanderen
0 0 0,5 0,4 0,1
Meren 0 0 0,4 0,4 0,2
Rivieren (Rijn) 0 0,2 0,5 0,2 0,1
Rivieren (Maas) 0 0 0,5 0,4 0,1
Benedenrivieren-gebied
0 0 0,2 0,5 0,3
River
Tijd voor hoog water (dagen)
4 3 2 1 0
Friesland & Groningen
0,05 0,2 0,5 0,15 0,1
Noord-Holland Zuid-Holland
0,05 0,1 0,3 0,45 0,1
Zeeuwse en ZH-eilanden
0 0 0,5 0,4 0,1
Zeeuws Vlaanderen
0 0 0,5 0,4 0,1
Meren 0 0 0,4 0,4 0,2
Rivieren (Rijn) 0 0,2 0,5 0,2 0,1
Rivieren (Maas) 0 0 0,5 0,4 0,1
Benedenrivieren-gebied
0 0 0,2 0,5 0,3
Time
Probability for available time for evacuation (combination of forecasting and decision making)
Extreme Wind
T+..T+1T0T-1T-2T-3T-4T-5T-10..6
Possib
le
Dik
e
Bre
ach
Detection and sense making
Early
Detection
Late
Detection
Extreme Wind
T+..T+1T0T-1T-2T-3T-4T-5T-10..6
Possib
le
Dik
e
Bre
ach
Detection and sense makingExtreme Wind
T+..T+1T0T-1T-2T-3T-4T-5T-10..6
Possib
le
Dik
e
Bre
ach
Detection and sense making
Early
Detection
Late
Detection
Citizen response / self reliance
‘Citizen Response’ pertains to all actions taken by citizens (Helsloot & Ruitenberg):
1. preparing for disasters and major accidents
2. during and after disasters and major accidents
3. with the intent to help themselves or others to limit the effects of the disaster or major accident
Conclusions:
• People make rational decisions on their interests, no panic or chaos
• Based on available information en knowledge
• Safety of family members is important
• Taking measures or preparation depends on perception of threat
Citizens response: Willingness to evacuate preventive or not
New Orleans Preventive Evacuation
Stay inside the threatened area
Enquiry 2004 (Heerden & Streva)) 68,8% 31,2% Hurricane Katrina 2005 (Wolshon) 80% 20% Hurricane Gustav 2008 (Cole) 95% 5% Next hurricane? Less / more
Willingness to participate in evacuation is uncertain
Netherlands (NIPO) Preventive Evacuation
Don’t know yet
Stay inside threatened
area
No opinion
River area with experience of evacuation of 1995
68% 28% 3% 1%
River area without experience of evacuation
of 1995
63% 34% 1% 2%
Coastal area that flooded in 1953
56% 38% 2% 4%
Other parts of coastal area 47% 49% 2% 2%
Traffic Management / Route Choice
What if all exits are used optimal (no ‘forced or informal’ connection region and route)?
Traffic Management / Route Choice
- Reduction of necessary time
- But model assumes:
- Perfect behaviour (route choice far from logical for each driver)
- Perfect implemented measures / decision making
- In reality the best case if not realistic
Expected sucess of preventive evacuation in The Netherlands
- Based on possible scenarios, probabilities in and event tree
Conclusion
• Flood policy has to deal with three layers (prevention, spatial planning and emergency management); standards has to be set for all
• The characteristics of a threat for flood and evacuation depends on space and time: Effectiveness of strategies of self reliance, and support of self reliance depends on actual circumstances
• A risk approach is needed for evacuation that takes uncertainty (threat, behaviour, decision making and environment) into account
• Capacity during emergency is limited, self reliance should be supported and facilitated
• Decision making is dealing with great consequences (economical impact because of the evacuation
• Thinking about evacuation is the start of a crisis (definition of a crisis ‘Rosental & Hart’)
• Authorities should prepare themselves, define standards, for all possible situations and during a crisis be able to select the most relevant; taking uncertainties into account and anticipate on consequences.
HKV CONSULTANTS
www.hkv.nl Contact: Matthijs [email protected]+31 (0)320 –294242
Bas [email protected]+31 (0)320 -294242
www.hkv.nl
Thank youk you
Questions?
Authorities
Self reliance public and organisation
Threat (size and (lead) time)
Physical environment
Context of ‘society’ for flood preparedness
Top Related