Volcanoes - Ministry of Civil Defence and Emergency Management

More documents

Recommendations

Info

Volcanic Hazard Risk Perceptions Kirsten Finnis, University of Otago; David Johnston and Douglas Paton, GNS in New Zealand Understanding a community’s perceptions of risk is an important part of any decision making process and should be considered an essential component in natural hazard management. Assessing risk by focusing purely on the physical processes that cause it does not fully accommodate the public’s assessment of risk. In the past this has led to problems in communicating hazard information and persuading the public to undertake appropriate mitigation measures. Research has shown that individual and societal perceptions of risk relate to planning behaviour, warning compliance and recovery. RISK PERCEPTION We are aware that people’s understanding of risk and response to risk are determined not only by available scientific information or direct physical consequences, but also by the interaction of psychological, social, cultural, institutional and political processes. The practice of “unrealistic optimism” and “normalisation bias” also influences beliefs about risk and risk reduction behaviour. Unrealistic optimism describes the situation where risk is amplified by people underestimating the risk to them and overestimating the risk to others. Thus, while people may acknowledge risk in their community, they are more likely to attribute its negative impacts to others rather than themselves. Normalisation bias results from people extrapolating a minor but rarely occurring hazard experience to a capability to deal with more serious consequences. Both these processes result in people underestimating risk (relative to scientific and planning estimates) and acting in ways that are counterintuitive. At the opposite end of the spectrum is the phenomena termed ‘social amplification of risk’. This problem arises when risk information communicated by sources, such as the media, overemphasises adverse or catastrophic aspects of a problem and fails to provide a balanced view. This was clearly evident during the 1995-1996 Ruapehu eruption. Much of this “social amplification” was fuelled by the media coverage which brought dramatic images of the eruption to people throughout New Zealand and the world. It can also arise in situations where there is a lack of trust in information sources, particularly when these sources dismiss the concerns, needs and interests of the community. Considerable attention, therefore, must be paid to tailoring risk communication messages to each group in the community as well as accommodating hazard source and impact characteristics, perceived personal consequences and effective reactions to the hazard information. Another issue to consider is that changing risk perceptions alone will not necessarily bring about behaviour change or increased action to address a particular risk issue. Rather, it is a function of a person’s thoughts, behaviour and interaction with their environment that governs the relationship between perceived risk and risk reduction actions. People may not be motivated to prepare if they do not perceive or accept their risk status or perceive hazards as more important. Irrespective of the level of risk, action will be constrained if people perceive hazard effects as insurmountable (low outcome expectancy), do not perceive themselves as having the competence to act (low self efficacy), or are not disposed to action (low action coping). Risk perception may not lead to action if people lack resources for implementation (low response efficacy), transfer responsibility for their safety to others (low perceived responsibility), lack trust in information sources, or because of uncertainty regarding the likely timing of hazard occurrence. A summary of findings from studies investigating risk perceptions of populations proximal to, or potentially impacted by, volcanic hazards from the Auckland Volcanic Field (AVF), Mt. Ruapehu and Mt. Taranaki/Egmont, are presented in this article. 60 TEPHRA June 2004
The majority of Auckland's 1.3 million people reside on the potentially active Auckland Volcanic Field (AVF). In a survey of Auckland residents in 2000, while 92% were aware that Auckland is built on a volcanic field, over 67% perceived it as being dormant. These studies use determinant factors such as hazard awareness, proximity to a volcano, perceived likelihood of future disasters, level of impact and past experiences of disaster impact. AUCKLAND The majority of Auckland’s 1.3 million people reside on the potentially active Auckland Volcanic Field. This field covers approximately 360km 2 and extends from Manuwera in the south to Takapuna in the north and contains about 50 volcanoes. While none of the existing volcanoes are expected to erupt again, a new volcano may erupt in this field at any location, at any time. Due to this random nature and the large population, only a relatively small eruption will be enough to cause major problems. Auckland is also capable of being affected by tephra fall from eruptions originating in the Taupo Volcanic Zone (TVZ) and from Mt. Taranaki/Egmont. The 1995/96 Ruapehu eruptions resulted in only ~1mm of ashfall on Auckland, but this was enough to cause disruptions to essential services and transport. Following a volcanic hazard information campaign (poster distribution) produced by the Auckland Regional Council, GNS and the Earthquake Commission, a study by Ballantyne and others (2000) found that nearly all of the Auckland residents surveyed (92%) were aware that Auckland is built on a volcanic field. However, a majority viewed the AVF as being dormant (67%), rather than potentially active. Just over half (55%) thought that Auckland is prone to volcanic eruptions and less than half (47%) perceived that a volcanic eruption is likely in the next 50 years. Although these results were marginally better than the pre-information campaign results, increased awareness of the volcanic nature of the Auckland region did not translate into increased perceived risk of this hazard. Two questions in the study further examined risk perceptions through testing recall of information specific to the poster. Firstly, the poster stated that the largest last eruption in Auckland was the eruption of Rangitoto, about 700 years ago. Yet only a low percentage (12%) of respondents correctly recalled that the last major eruption in Auckland occurred between 500-700 years ago and over a third (35%) were unsure of the timing. Secondly, the poster stated that it was unlikely that a future eruption would occur at the site of an existing cone. Over half the respondents (53%) ‘recalled’ that the next eruption will occur from an existing cone, with only a third (31%) correctly stating that an eruption will occur in another location. As understanding of these issues remained relatively poor, so did risk perception. The fact that a majority of the respondents perceive a threat from an existing cone causes problems as those not living close to a cone will perceive little risk. As acknowledged in the report, future information campaigns need to examine 61 TEPHRA June 2004
Page 1 and 2:
TEPHRA KIA TAKATU TAHI TATOU Septem
Page 3 and 4:
Living with Volcanoes Contents 2 Vo
Page 5 and 6:
Volcanism has played an important r
Page 7 and 8:
y collapse of the summit area to fo
Page 9 and 10:
Dominating the central North Island
Page 11 and 12: main crater in 1914, forming a debr
Page 13 and 14: amounts of sodium and potassium tha
Page 15 and 16: 1976) and conflicts over staff prio
Page 17 and 18: Vertical deformation in the caldera
Page 19 and 20: Level are made by an event coordina
Page 21 and 22: So what do we call this magnificent
Page 23 and 24: Coastal ring plain showing volcanic
Page 25 and 26: Egmont/Taranaki. The real truth is
Page 27 and 28: Security Coordination-DESC) to moni
Page 29 and 30: Our research at Massey University h
Page 31 and 32: Crater Lake at Ruapehu viewed from
Page 33 and 34: it is also the responsibility of al
Page 35 and 36: oes This article outlines how the
Page 37 and 38: 2. Allowing for immediate communica
Page 39 and 40: AUCKLAND ENGINEERING LIFELINES PREP
Page 41 and 42: Volcanic eruptions can result in a
Page 43 and 44: Soiling interiors Ash can enter a b
Page 45 and 46: conditions, overloading of telephon
Page 47 and 48: approaches can be used: • Policy
Page 49 and 50: In about 1315AD Tarawera volcano er
Page 51 and 52: ASHFALL IMPACT SCENARIO 300mm (30cm
Page 53 and 54: schools (if there is need for a rap
Page 55 and 56: The Okataina Threat for the Bay of
Page 57 and 58: to return. How are we going to cope
Page 59 and 60: neighbouring districts in order for
Page 61: AT THE UNIVERSITY OF OTAGO • Jame
Page 65 and 66: mountain in their backyard’ will
Page 67 and 68: BE PREPARED There are seven active
show all

Volcanoes - Ministry of Civil Defence and Emergency Management

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?