Evacuation in case of large scale flooding in The Netherlands

1. Evacuation in case of large scale flooding in The Netherlands 3 March 2010 Matthijs Kok, Bas Kolen HKV consultants www.hkv.nl

2. Topics Introduction Flood policy in The Netherlands Definitions of evacuation Evacuation scenarios Discussion about model assumptions Conclusion and questions

3. 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)

4. Flood policy in The Netherlands 1953: “This may never happen again” Focus on prevention • International high safety level • Low probability, mass impact 3. Policy (since 2008 National Water Plan): • Prevention (law) • Spatial planning • Emergency management (planning, forecasting)

5. Flood protection in The Netherlands 1. Coast and river 2. Canals 3. Rainfall

6. 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)

7. Possible scenarios • Size (large, small) • Forecast (lead time: early, late) • Threatened area is sum all possible scenario’s, threatened area is related to window of forecast ‘Safety Standards’ Katwijk ‘Safety Standards’ Rotterdam

8. Worst Credible Flood ‘upper limit’ 4300 square km120 Mld Euro 10.000 casualties movie

9. MPT/IPT NCCC NCC NOCC Driebergen The Hague PCC RCC MCC Organisation crisismanagement

10. 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: • Preventive evacuation: Movement before start of disaster to a place outside threatened area • Shelter (Horizontal and vertical evacuation): Movement before start of disaster to a shelter of safe haven inside threatened area • Shelter in place (only vertical evacuation): Move to upper floors • Acute evacuation: Movement after start of disaster before being exposed • Rescue:Movement supported by first responders after being exposed • Escape: Movement by self reliance after being exposed

11. Evacuation in The Netherlands Study ‘National Security, capability based planning’: • 4 different strategies of evacuation • 4 types of traffic management • Reference • Nearest exit • Optimal use of exits • Flow off areas • Risk zoning in threatened area based on realistic forecasting (all possible floods)

12. National Security

13. Traffic Management / Route Choice

14. 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

15. Results: Bottle necks

16. Results: Extern bottle necks Movie: National concept evacuation (best case), preventive evacuation 48 hours after start Bottle necks outside ‘evacuation zone’ when also considering outflow

17. Results after 33 hours Advance national traffic management after 33 hours: • Evacuation population x 1000 • % success in 33 hours (available time during Floodex) 70072% 3200 33% 140 80% 170 72% 10080%

18. 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

19. Discussion • Available Time • Behavior of people • Traffic management / Route choice • Expected success of preventive evacuation (taking all possible scenarios into account)

20. Extreme Wind Detection and sense making Early Detection T-10..6 T-5 T-4 T-3 T-2 T-1 T0 T+1 T+.. Late Detection Possible Dike Breach Available time • Uncertainty in forecasts (nature) • Uncertainty in interpretation of forecasts by decision makers and willingness to take action

21. Time River Coast Available time Probability for available time for evacuation (combination of forecasting and decision making)

22. 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

23. Citizens response: Willingness to evacuate preventive or not Willingness to participate in evacuation is uncertain

24. Traffic Management / Route Choice What if all exits are used optimal (no ‘forced or informal’ connection region and route)?

25. 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

26. Expected sucess of preventive evacuation in The Netherlands • Based on possible scenarios, probabilities in and event tree

27. 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.

28. Thank youk you Contact: Matthijs Kok m.kok@hkv.nl +31 (0)320 –294242 Bas Kolen b.kolen@hkv.nl +31 (0)320 -294242 www.hkv.nl j.k.leenders@hkv.nlwww.hkv.nl Questions? HKV CONSULTANTS

29. Context of ‘society’ for flood preparedness Authorities Threat (size and (lead) time) Physical environment Self reliance public and organisation