Descripción del flujo de proceso

The overall objective of this thesis is to increase the understanding of evacuation and how to deal with uncertainties with regard to flood risk management. This knowledge contributes to adaptive evacuation planning as introduced in this thesis. This overall objective is specified in six objectives:

1. Develop a set of definitions for evacuation, including different types of evacuations; 2. Define what is understood by ‘being prepared’ and how the effectiveness of evacuation

planning can be related to specific requirements in a risk based approach;

3. Develop an model that describes the effectiveness of evacuation strategies as preventive and vertical evacuation that takes uncertainties into account;

4. Define an risk based approach for decision makers to select measures of different layers as prevention, land use planning or evacuation and emergency management to design a system with regard the acceptable level of risk;

5. Define a crisis management approach for decision makers (using thresholds) to call for the ‘go or no-go’ decision for evacuation as well as thresholds for other phases of evacuation planning;

6. Develop an adaptive approach for evacuation planning and decision making for low frequent but large scale events when multiple stakeholders are involved and the consequences of evacuation itself will significantly impact economic and social processes.

1.4

Methodological choices and assumptions

1.4.1

Integration of natural and social sciences

This thesis combines engineering and natural sciences with social sciences. The natural sciences test the validity of claims, while the social sciences depend much more on our interpretation of social phenomena as well as the yardstick used to distinguish between different alternatives as described by (Jongejan 2008). The natural sciences can be used to define flood risk and the effectiveness of evacuation. Social science is also needed to define the effectiveness of the emergency response, as emergency planning can be seen as a guide for behaviour for certain situations (Drabek 1990). Additionally, before a situation can be seen as an emergency, a (collective) decision must be made to define it as an emergency (Drabek 1985).

This results in a holistic approach for evacuation planning or emergency planning as a layer or part of (flood) risk management. This approach can be used to define the appropriate response based on the circumstances of the disaster and the social structures in place. The holistic approach aims to maximise the effectiveness (and reduce loss of life) of measures

implemented by authorities, emergency services and, most importantly, citizens. This planning approach does not focus on “control” but rather “facilitation” by the authorities during evacuation.

This holistic approach combines knowledge of statistics and scenarios with expert judgment and consensus. This requires the use of knowledge about flood risks, statistics, traffic management, decision making processes and behaviour. It is also necessary to handle with lack of knowledge and the ability to establish agreement among experts and policy makers regarding how to address gaps in knowledge for emergency planning and decision making. Experts, planners and policy makers must reach a consensus about how they will address certain topics and situations bases on the available knowledge and experience. Experts have an important role in the estimation of probabilities of positive and negative scenarios for evacuation based on available planning and risk perception. Experts are also required to describe the relationship between certain measures and their consequences, such as the behaviour of people. Policy makers have to define requirements for evacuation. In addition research, evaluation of real events and exercises can broaden the existing knowledge and be used for further improvement. In the meantime, the consensus is the fundamental basis of emergency planning: it is possible to combine all measures initiated by several planning documents and to define the consequences in the case of an event.

Previous PhD research in the Netherlands has focused on specific elements, such as flooding scenarios (Alkema 2007), uncertainties in these scenarios (Moel 2012), transport modelling (Pel 2011), loss of life (although this research also used a more broad scope with respect to the risk) (Jonkman 2007; Boyd 2011), and public perception (Terpstra 2009) and optimised guidance instructions for preventive evacuation (Huibregtse 2013). This thesis focuses on the interaction of different elements, such as threat and impact, the environment and infrastructure, decision making by authorities and citizens, as well as the role of time in evacuation planning and (top strategic) decision making. Therefore, it contributes to (multiple layer) flood risk planning and specifically to evacuation and emergency management. Decision makers can create the circumstances of an evacuation in the future based on the situational picture of the event and based on planning. Preparation should focus on the ability to create these circumstances.

1.4.2

A rational approach is followed

This thesis is based on a rational approach to evacuation and emergency planning. This ration approach is risk based and uses cost benefit analyses applied for low frequent events with a high impact. In reality, the process of decision making is sometimes subjective; however, knowledge of the risks (defined as the probability x consequences), the costs and the benefits of the measures and knowledge of the consequences of uncertainties improves decision making (Tversky and Kahneman 1974). The rational figures can be compared to other criteria by decision makers (Kolen and Helsloot 2012a; Jongejan 2008). Therefore, the approach developed in this thesis can be used to:

1. Further improve the effectiveness of evacuation planning and emergency management; 2. Develop flood risk management strategies that contain multiple layers of emergency management (such as prevention, land use planning and emergency management); 3. Minimise the total costs in risk based strategies or loss of life based on the available

infrastructure and emergency equipment;

4. Develop special evacuation strategies to minimize loss of life for people with special needs (as in hospitals);

5. Define the minimal conditional (given a forecast) probability of flooding to call for evacuation taken the economic consequences of evacuation into account as well as loss of life and risk aversity.

This study is based on a holistic approach. The whole society is considered as a system in which all stakeholders (authorities, citizens) can interact, structures exist that describe the relation between these stakeholders and stakeholders might be confronted with the consequences of measures by others. All stakeholders function inside a network with formal and informal relationships. It is assumed that the responsibilities of a government are spread over several organisations over several levels as a federal, national, regional or local level. This is the case in most democracies. The possibility of implementing measures depends on, for example, the following:

1. The availability, lead time and quality of forecasts; 2. The available infrastructure (roads, buildings);

3. The available equipment (fire trucks and police vehicles, trucks and ambulances); 4. Emergency personnel;

5. Equipment and personnel in the private and sector; 6. Self-response (or citizen response);

7. Ability to adapt the infrastructure and equipment or reallocate them; 8. Fallibility of emergency management and evacuation planning.

The possibilities for implementing effective measures also depend on the threat or consequences of the disaster itself.

For low frequent events as flooding in the Netherlands, it is overly optimistic to assume that uncertainties and gaps in knowledge can be completely eliminated. However, at this moment, decisions for evacuation might be necessary as well, and these have to be based on the available and required information. More information than required however can hamper decision making as seen during exercises as Waterproef (Cappelleveen and van der Ven 2009) and SMO (Arcadis 2013), see also section 5. The combination of knowledge and expert judgement can therefore be used for proper adaptive and connected preparation.

1.4.3

Incentives for evacuation by different stakeholders and cost benefit

analyses

The objective of a mass evacuation can be seen from different perspectives. Objectives can be defined on an individual basis, from the perspective of a private or governmental organisation or by considering the overall perspective of the whole society. In this study the total costs of a society are considered (the combination of the risk and investments). These total costs can be used to define requirements for evacuation. However given the requirements stakeholders will have different incentives to act, examples of objectives are as follows:

Individuals:

 A citizen or person has their own interests and interpretations of the risk. Each citizen defines what is important to them in the case of a crisis (Helsloot and Ruitenberg 2004), and people tend to evacuate only when others in the same group are willing to evacuate (Perry 1985; Tierney 1989; Perry and Mushkatel 1986);

 A decision maker could use a crisis as an opportunity to implement measures to influence later elections.

Private organisations:

 A private organisation will try to reduce the economic impact and damage to their infrastructure. Examples are companies that offer shelter in place for a more quickly start-up of their processes (Ball 2006) or the continuity of industrial processes. For a factory, a break in production will cause as much damage as a flood, as was seen in Tiel during the evacuation of 1995 in the Netherlands (Volkskrant 1995). The board of a hospital that will take care of the patients will also have financial objectives.

Government:

 A governmental organisation will optimise the continuity of its role and must also provide for the needs of the citizens. The road management centre, for example, will optimise the use of the roads, but administration for loans and taxes must also continue;

 The required performance during evacuation as part of a risk based strategy can be defined in advance and be used as yardstick for evacuation planning and training and exercises.

A cost-benefit analysis assesses the optimal investment strategy of flood risk management for a society, taking into account all of the costs and benefits. Based on a cost-benefit approach, the need to invest in multiple layers can be defined related to the reduction of the risk or the contribution to evacuation as well as the costs of the measures. In addition, these measures can also contribute to other objectives of a society. For example, just as a dike can be used for multiple forms of land use, a fireman can also be used for other purposes besides flood risk management. Furthermore, spending can be increased for other reasons, such as other objectives (e.g., the environment) or even a symbolic feeling of being safe. In this thesis, only the consequences with regard to flood risk management are taken into account. The use of a value for the loss of life in the quantitative cost-benefit analyses can offer insights into the effectiveness and costs of such measures. Whether the approaches are risk-seeking or risk- averse, different competing strategies or measures can be compared rationally based on the benefits and costs of every alternative (Benjamin and Cornell 1970). Additionally, the cost of human life has been taken into account as discussed in several studies (Viscusie and Aldy 2003; Vrijling and Gelder 2000; Jongejan et al. 2005). This topic is further discussed in part III of this thesis.

1.4.4

Emergency services are already in place and independent with regard to

flood risk management

The complexity of emergency planning for low-frequency mass events is well known (McConnell and Drennan 2006; Quarantelli 1988; Clarke 1999; Helsloot 2007). The objective of this thesis is to obtain a better understanding of evacuation for low frequent and large scale disasters and describe a method for emergency planning based on criteria that are related to consequences (as damage, loss of life). Therefore, evacuation can be integrated in a risk- based approach and cost-benefit analyses.

Hence, this thesis focuses on the existing delta where people live and work. Emergency services (as fire and rescue services, police and medical services and the army) are already part of a society. These services are often designed and focused on small emergency incidents and emergency disasters, such as building fires, car accidents, etc.

These services can also be used to mitigate the impact of (low frequent) floods although these might not be designed for this.

In a reference strategy where no special measures to prepare of flooding are taken by emergency organisations, it will only be by accident that the outcome will result in optimal emergency management actions. In this thesis, it is assumed that the emergency equipment, personnel and infrastructure are, in principle, based on normal tasks and not related to evacuation or flood risk in particular.

The reduction of the impact of these measures depends on the impact of a disaster and the available time and capability available to implement the measures. The level of additional preparation for flood risk management can be related to the required contribution to the acceptable level of risk of a type of disaster. Criteria have to be set by politicians or policy makers. When additional infrastructure, personnel or equipment for evacuation in the case of flood risk are required and are part of the design of the emergency management structure, this is referred to as an ‘add on’ to the normal capacities. Such an add-on has to be justified by the reasons for the evacuation, although the extra capacity might also be useful for other activities.

In the crisis management literature, there is an increase in attention (and expectations) to the resilience and flexibility of organisations (Cutter et al. 2008; van Duin 2011; Norris et al. 2008). This can result in a more effective response and less damage or loss of life. In case of a flood and mass evacuation the capacities of rescue organisations (number of rescue workers, equipment) and capacity of infrastructure is overwhelmed because the required capacity exceeds the existing capacity. From the perspective of adaptive planning, a resilient and flexible organisation can create better circumstances for evacuation to facilitate evacuation. This is another objective than, for example, increasing the number of people that are directly saved by the emergency workers of the specific service. This is, in fact, a management problem that exceeds the primary role of governmental organisations or emergency services, but it is a question that all authorities must address together. However, the management of each organisation defines the objectives of their own organisation and personnel. The most effective measures for the society might not be related to normal day-to-day work or activities that are effective for specific emergency services. Procedures might need to be skipped because these could limit the possibility to evacuate (for example, because they take too much time). Decision makers and emergency managers should therefore anticipate this situation because all emergency workers are trained to address unforeseen situations and, based on their role; automatically begin to act with or without the involvement of these managers.

1.4.5

Words of caution

In a perfectly controlled world, when decision makers and citizens always have perfect information, no accidents occur and no uncertainties exist. In such a world this thesis can be criticised because the moment when to take which measure can be defined in advance. On the opposite, when the event is 100% uncontrollable, the results can also be criticised because this thesis is based on scenarios that describe the relationships between parameters and how capacities are used.

Complete compliance of citizens and decision makers is an ideal but unrealistic situation, as is the availability of all information which is needed. A survey of decision makers (see section 4) resulted in discussions with several Dutch mayors (see section 5 for this survey).

Personal communication of the author with some of the mayors indicated that some mayors assume a perfect world or a complete chaos. A group of mayors indicate that they will directly follow the national instructions and claim that they have no role in the decision making process for evacuation. Other mayors claim that they are not concerned with the higher levels of decision making and will decide for their own case. Most mayors however, as shown in the survey, follow a risk-based strategy. Because emergency structures connect different local regional and national authorities, an overall strategy can be formed. However, this must take into account that compliance will not be 100%.

From the perspective of an economist (in a world of limited budgets), it can be questioned whether investments should be made in emergency planning when investments can also be made in flood prevention and are more cost effective. An additional argument not to invest in emergency management is based on the probability of the failure of the emergency management system because it depends on human actions in low-frequency events, while levees are constructed only once and need less frequent maintenance. From a more political standpoint, there is also pressure to invest in measures that create a feeling safety to influence public perception.

Additionally, because the experience with mass evacuation (by definition) is limited, new insights can result in better as well as worse preparation. When only a few stakeholders implement measures, these might block measures taken by others. Therefore, discussions among experts should be organised to understand experiences and new knowledge and to come to a consensus on how this information should be used in tested and maintained emergency planning.