3.3.1
Background of transition phase
The transition phase reveals the role of top strategic decision making in the mass evacuation, which consists of creating conditions for other decisions to be made and emergency measures to be implemented in the near future by authorities, emergency services and citizens. Top strategic decision making for mass evacuation addresses the strategy for evacuation with regard to (1) when to initiate an evacuation and (2) the type of the evacuation (preventive, vertical or the use of shelters) to create the optimal circumstances for the evacuation. The top strategic decision maker is at the top of the decision making tree. For the Netherlands in the case of large scale flooding, this will be the Ministerial Policy Team lead by the political leaders of all departments. Top strategic decision makers will automatically be confronted with many choices, great uncertainties and great consequences in all circumstances. Uncertainties occur, for example, in the prediction of flooding (size, probability of occurrence) (ten Brinke et al. 2010; Kolen et al. 2011a), the effectiveness of emergency measures (Kolen and Helsloot 2012b) and uncertainties about how other stakeholders (as local authorities, first responders and citizens) will respond.
When forecasts become clearer and uncertainties of forecasts decline as shown in Figure 16, people and decision makers begin to act over time. The autonomous response of citizens can create an overload or inefficient use of the road capacity, the available equipment and limitations for authorities to implement further mitigating measures. Several models describe the possible response of citizens in the case of a natural hazard based on the interaction between environmental processes, social processes and individual processes (Lindell and Perry 1992; Kolen et al. 2012b; Grothmann and Reusswig 2006; Sorensen 2000). In the case of evacuation due to flooding, it is known that not all people will act directly after receiving the warning, as it takes time after a warning before people will begin to evacuate (Lindell et al. 2002). Because floods do not respect administrative boundaries, multiple decision makers are involved. The autonomous response of these decision makers can result in counterproductive measures as well as less optimal use of the available resources and infrastructure.
The impact of these ‘top strategic decisions’ depends on the possibility of creating the circumstances that facilitate the future response by several stakeholders and citizens. Literature described this process as reflective decision making: the decision has to be made in relation to the decisions of others (Rasmussen et al. 1991). These top strategic decisions have to be made based on information about forecasts and scenarios for evacuation and before people begin to act. These decisions create a transition from normal life to a mass evacuation mode. This period is called the transition phase.
For evacuation planning, authorities in the surrounding areas are important to support evacuation operations (such as traffic management, offering shelter, delivering equipment and services, etc.) (Wolshon 2006; Wegh 2008; VenW 2008). Emergency planning (VenW 2009a; VenW and UVW 2010; BZK 2008a), research on evacuation (Kolen and Helsloot 2012b; Jonkman 2007), the experience of Katrina (Parker et al. 2009) and exercises (TMO 2009b) carried out in in the Netherlands indicate that pro-active and direct involvement at the national level is necessary to increase the effectiveness of emergency measures in the case of a national disaster.
The response to Hurricane Katrina and during the mass evacuation of Rivierenland in 1995 showed the importance of and the difficulties associated with top strategic decision making. For example, difficulties were encountered in getting the relevant partners involved in time and determining the moment to call for a preventive evacuation. During Katrina, the consequences of previous evacuations were visible to people who did not want to evacuate because they hoped or assumed that the hurricane would not hit their area (Parker et al. 2009). Some research stated that earlier involvement at the national level (such as FEMA and the Red Cross) might have reduced some of the consequences (Parker et al. 2009). The top strategic decision to get the national level involved more early for the response was one of the lessons learned in New Orleans as well as in the Netherlands (van Duin et al. 1995). During hurricane Gustav in Louisiana, the national level made a concerted effort to engage with the situation and to show that they cared about it, were aware and responded (Cole 2008). Although this is not clear evidence, it surely affects the perceptions of professionals and the public. Other factors contributing to the Gustav response were, for example, the recent history with Katrina.
In this chapter, the general phases of evacuation are introduced to describe the process and the ability to influence the circumstances of an evacuation and to execute an evacuation. These phases can be used to describe relationships over time between the four elements in the evacuation framework. From the perspective of a decision maker the first phase is during preparation, the last three phases are initiated in the case of a threat:
Phase 0: Planning and design of layered evacuation in a multiple layer safety system; Phase 1: Detection and recognition (sense making) after early warning;
Phase 2: Organisation and decision-making by leaders and citizens; Phase 3: Period of moving from one place to another.
Uncertainties have an important role in the process of planning and decision making for evacuation, which becomes clear after analysis of the different elements in the next sections.
3.3.2
Phase 0: planning and design
The phase of design and planning establishes the boundary capacities (such as the road capacity, the equipment, etc.) and capabilities (how to use the available equipment) for a future evacuation. Each society already contains infrastructure, emergency services and emergency structures that will be used for evacuation, even without specific preparation. During this phase, measures can be implemented to accomplish the following:
Increase the capacity of the infrastructure by, for example, adding road capacity or developing shelters;
Increase the capacity of the resources of emergency services, for example, by providing extra personnel or equipment;
Improve the use of the available means and infrastructure by conducting additional research, planning, performing risk perception and training and exercises.
The need for these measures depends on the defined requirements for evacuation. A model to define these requirements in a risk based approach is described in section 9.
3.3.3
Phase 1 Warning: Detection and recognition (sense making) after an early
warning
Phase 1 describes the process of how signals are detected and understood regarding a threat. Signals of a (possible) disaster can be detected and recognised by experts, citizens, etc. These signals have to be accepted and understood by crisis managers and decision makers (this process is also called sense making, as described by (Boin et al. 2005)). In Figure 13 a probability distribution of the lead time is presented, this probability distribution is divided in three classes (a best case, a worst case and an expected time of detection). After the moment of detection by an expert, the sense making process of the experts and others begins.
Figure 13: Phase 1 Warning: Probability distribution of lead time
Phase 1 is initiated by the detection of a possible threat. Decisions will only be made when someone defines the problem and addresses the need to take decisions about the implementation of measures. In addition, it is required that decision makers and their advisors be willing to spend time and effort to obtain and understand the available information. Although this seems very clear (and especially with hindsight when, as for example in the case of hurricane Katrina, more efficient measures could have been taken, see (Parker et al. 2009)) this is less clear in a situation when information contains uncertainty and
the impact of decisions is very large. Experts have to put the warning for a low frequent and uncertain event on the agenda of crisis managers and decision makers to initiate decision making. It may also be decided that no measures will be taken or decision are delayed. This is also seen as a decision because it is chosen to influence an on-going process. Figure 14 illustrates a probability distribution of the period between detection and warning and decision making.
Figure 14: Phase 1 Warning: Probability distribution of time needed for sense making, planning and decision making given a moment of detection and warning
The existence of clear triggers and thresholds based on measurements or forecasts gives no guarantees that decisions will be made in time. Clear triggers related to actual or expected values, such as water levels, to alert the experts and decision makers can encourage them to act in time. However, these triggers can also create some blindness because of uncertainty (especially using only automatic warnings) when these criteria are not understood (Boin et al. 2005). When the threat does not meet the criteria, a warning might not be given, even when it is clear that the event might be extreme or experts indicate the risk. An example in the literature shows a case in the Alps of extreme weather. The use of defined criteria resulted in a missed call for the first event, and for the second event, precaution measures were taken while nothing happened. A better use of the knowledge of the forecaster and the results of the forecasts could have prevented both outcomes (Kroonenberg 2010). The moment of detection cannot be defined in advance as already illustrated in Figure 13 and discussed in more detail in section 4.
3.3.4
Phase 2 Transition: Organisation and top strategic decision making
Decisions for alternative strategies are based on information and perception of the information gathered in phase 1. Governmental decisions have to take into account the possibility of the reduced availability of infrastructure caused by traffic jams following spontaneous evacuation or an unexpected citizen response. In that case, changing to a different strategy seems plausible, but might be impossible or highly ineffective. Transportation and movement for rescue services, if available, also requires more time in conditions of traffic congestion.
During the transition phase, the authorities can consider adapting the infrastructure, reallocating the means and rescue workers and informing the public about the consequences to increase the later effectiveness of emergency measures as discussed before in section 3.3. This process is illustrated by Figure 15. This figure shows the autonomous response of citizens’ (and operational centers, emergency services etc.) over time. In case of a threat people will act because they feel threatened (see more in section 7). When more people evacuate autonomous the effectiveness of top strategic decision making will decline over time. This reduction of effectiveness is because first responders are already active, travel time increases dramatically and for example fuel is running out. Therefore the time to implement measures is far more than in normal conditions.
Figure 15: Effectiveness of top strategic decision making related to the autonomous response of citizens’ over time
The following are examples of top strategic decisions that can be made during this transition phase with regard to ‘communication’, ‘policy measures’ and ‘operational measures’:
1. Communication with the public about the risk, consequences (and time lines) of the threat and possible emergency measures, the impact of uncertainties and how to call for assistance;
2. Policy decisions to influence other authorities. Warn the relevant national and regional authorities (if not warned already). Define the go/no-go decision and strategy for evacuation (preventive, vertical, shelter in place or a combination). Inform other authorities about the risks, consequences (and time lines) of the threat, as well as the possible emergency measures, the impact of uncertainties and how to call for assistance (or already implemented or foreseen emergency measures, such as national traffic management), juridical arrangements and international agreements;
3. Define operational emergency measures to adapt the environment and infrastructure, for example, implementing (evacuation) traffic management, identifying the evacuation routes and disconnecting them of other routes, assigning regions that will offer public shelters, prioritising the use of the limited available (national) emergency equipment and personnel (such as the army and national operational services), reallocate regional emergency equipment and personnel (including the army forces) and call for international assistance.
3.3.5
Phase 3 Movement: Period of moving from one place to another
During this phase, the logistic process of the mass evacuation is on-going. During the evacuation, the situation will develop very quickly. All involved citizens, emergency services and authorities implement their measures within the (new) boundary conditions created in the evacuation mode. The time needed for evacuation depends on the destination, the route and available road capacity and the numbers of evacuees. The required time to execute the measure also depends on the consequences of the actions of others as well as the available road capacity and the numbers of evacuees (Kolen and Helsloot 2012b).
While the evacuation is on-going the effectiveness of coordination to support local problems is limited. Emergency services and citizens confronted with problems will solve them with the available means or face the problem (Scholtens 2008). Changes to another evacuation strategy, because new information about the threat or better scenarios is available, will be very complex because the entire logistic process has to be influenced. All emergency services and citizens must be informed about the new strategy, routes, etc., which might cause reallocation of emergency equipment and a creation of a new evacuation mode. This complex operation may create all kind of disturbances and even gridlocks; it can be questioned if such an operation will increase effectiveness of evacuation.
3.4