a conclusion about relevant risks. In general, the public relies on what are called ‘heuristics’ or – more commonly – rules of thumb. Heuristics are quick, informal methods that the brain uses to generate an approximate answer to a problem and allows people to quickly make sense of a complex environment (Renn 2008).
However, using heuristics can also result in biases, where risk perceptions are out of kilter with risk assessments by emergency agencies or other authorities. For example, if someone has experienced a hazard event, they are likely to see one as more probable in the future. Consequently, personal experience can be very important in perception of the level of risk, and reminders of particular risks in the media can also have an effect (Eiser et al. 2012). This ‘availability bias’ through personal experience or ‘local knowledge’ can improve local risk assessment by authorities through a cooperative approach (Dufty 2016).
‘Optimism bias’ is a cognitive bias that causes people to believe that they are at a lesser risk of experiencing a hazard event compared to others. This can cause them to opt out of any thinking (and resultant action) towards a particular disaster risk, believing ‘this is not going to happen to me’. On the other hand, individuals may tend to overestimate the potential for exposure and the extent of a hazard, thinking that they are more dangerous in comparison to other risks (Science Communication Unit 2014).
Of importance to risk communication is the fact that research shows cultural background influences risk perception. Compared with individuals in Western Europe, for example, people from many Eastern European countries are more likely to see economic or social risks as greater than technological risks (Science Communication Unit 2014).
Renn (2008) has designed a model of risk perception which shows the dynamics between the complex layers of factors, including cultural background, heuristics, and biases. Also of note are people's beliefs and values, their socio-economic status, and world views.
The relationships between risk perception and emergency behaviours (e.g. preparedness, evacuation, and recovery) are discussed in Section 5.2.
2.2.1.3 Trust
Trust in the communicator is an important factor of risk perception with strong ramifications for effective risk communication. It becomes even more important when the individual's knowledge about the hazard is low and they have to depend on authorities for risk knowledge (Cope et al. 2010). Also, there seems to be a strong relationship between the uncertainty of the risk and the role of trust (Frewer and Salter 2007).
According to the Science Communication Unit (2014), research suggests that three main factors influence trust in an institution:
1 competence (i.e. the knowledge and capability to manage the risk in question);
2 a history of being open and honest and acting in the public interest;
3 sharing the same values as the individual.
2.2.1.4 Communicating Risk
Risk communication seeks to inform people about a potential future harm and the associated dangers so that they might take action to mitigate the risk.
A long tradition in risk communication has relied on the idea that simply informing people will increase their understanding and awareness of risk. This approach assumes that experts (e.g. emergency agencies), holding superior knowledge, communicate to the less informed (e.g. at-risk people). However, it has been found that a direct, linear approach to providing official information to increase recipient awareness does not necessarily lead to action (Fischhoff 1995).
Furthermore, appreciation of the input of at-risk people in disaster risk has broadened the scope of risk communication. As a result, communicative activities that place responsibility for preparedness actions in the hands of citizens are gaining relevance (Begg et al. 2016). With this in mind, four approaches of risk communication can be distinguished related to the one-way and two-way communication dimensions (Terpstra et al. 2017).
1 Risk message approach. This type of risk communication is a one-way flow of information from an expert source so that it is received in a consistent and accurate manner. For example, details of flood risk can be communicated by a risk map which provides clear details of flood extent to all.
2 Risk dialogue approach. In this two-way risk dialogue approach, the distinction between risk experts and the at-risk public is a blur. Here, participation allows for the inclusion of local knowledge from the at-risk public that can improve the quality of risk assessments and risk maps, as well as of the management process itself.
3 Risk government approach. Communication within the one-way risk government approach aims at changing attitudes and behaviours. This is done by authorities creating awareness of people's hazard risks and the consequences that related decisions might have on their lives.
4 Instrumentalist risk approach. This two-way approach aims at actively changing people's behaviour and pays close attention to the ‘interactions between information, attitudes, and behaviour’ (Demeritt and Nobert 2014). Underlying the instrumentalist risk approach, many empirical studies focus on understanding the factors that motivate individuals to take responsibility and action in order to increase their disaster preparedness (Shreve et al. 2014).
2.2.2 Crisis Communication
Crisis communication relates to communication as an emergency or disaster event unfolds, and as part of recovery from that event. However, Steelman and McCaffrey (2013) contend that crisis communication and risk communication should be merged in a more holistic, event-based approach. Their rationale ‘is that large-scale shifts in management response likely need to be communicated before as well as during an event, as effective outcomes may be dependent on how the communication in one period influences another’.
Crisis communication has its roots in crisis management and public relations (Williams and Olaniran 1998) and traditionally focused on the message and how it is delivered during and after the event.
2.2.2.1 Early Warning
The primary aim of an early warning system is to provide people with enough time to make themselves safe when a threat to them is imminent. A secondary aim is the protection of property. It is also important to try to ensure the safety of companion animals and livestock such as sheep, cattle, and horses.
According to Mileti and Sorensen (1990), ‘a warning system is a means of getting information about an impending emergency, communicating that information to those who need it, and facilitating good decisions and timely response by people in danger’.
Early warning is the bridge between risk and crisis communication. ‘Early warning is not only the production of technically accurate warnings but also a system that requires an understanding of risk and a link between producers and consumers of warning information, with the ultimate goal of triggering action to prevent or mitigate a disaster’ (International Federation of Red Cross and Red Crescent Societies 2009).
Clear, timely, and accurate warning information should be communicated to at-risk communities. The International Federation of Red Cross and Red Crescent Societies (2014a) states that ‘the outputs of an early warning system must recognise the diversity of the audience and be appropriate to that audience. Outputs should be contextualised, granular and specific to potentially impacted localities. They should include clear explanations of degree or severity, of trend, of timing, and of the confidence associated with the prediction. The choice of the language and the medium of the communication should be appropriate
