Canterbury University. New-Zealand: The Christchurch earthquakes demonstrate that people generally do not
take any notice of the likely occurrence of rare events, University of
Canterbury natural hazards researcher Professor Tim Davies says.
The February 2011 earthquake was a one in a many thousands of years’
event and there were many more important things to worry about prior to
the 4 September 2010 earthquake, he says.
Professor Davies is attending and speaking at the United Nations
world conference on disaster risk reduction in Sendai, Japan, from 14 to
18 March.
The conference hopes to produce countermeasures to climate-related
disasters, which are worsening in some parts of the world. Japanese
organisers will draw on its experiences of the March 2011 quake and
tsunami and help stress the importance of preparation.
“Before the Christchurch earthquakes, large in our minds was an
Alpine fault earthquake. We started preparing for that potential event
in the 1990s and 2000s because it had a much greater probability of
occurring than anything else we knew about. The lesson here is that
probabilities do not tell us everything future about disaster events –
especially the ones we don’t have much information about.
“The most important disaster for any community is the next one, and
probabilities can tell us nothing about that. We cannot know far in
advance its type, its intensity or its time of occurrence. What any
community needs to know is what the next disaster can do, and prepare by
altering its behaviour so that when any disaster happens, the effects
will be
reduced.
“A community could, for example, anticipate that any disaster can cut
off its food supply, and maintain emergency stocks; it can arrange that
all the major professionals such as doctors, police and fire crew do
not work in the same building, so that all don’t get wiped out by the
same event.
“It can purchase and maintain satellite phones, anticipating that a
range of events can knock out mobile and landline communication. None of
these requires that the nature and probability of the next disaster are
known.
“It is legitimate to use methods to devise risk-based strategies for
dealing with the cumulative effects of large numbers of disasters,
because the statistics will in that case be close to what actually
occurs. However, such large scale strategies cannot be effective at
reducing local disasters, because these are all different. If local
disasters aren’t reduced, no large-scale disaster reduction strategy can
be effective.
“Communities need to develop, in collaboration with scientists and
officials, their own views on what the next disaster can do to them, and
how they can become less vulnerable to it. The community itself knows
how it functions; scientists can tell them how nature behaves; and
officials can if necessary alter rules to allow resilience to be
improved.
“There is much we do not know about natural hazards, and disasters
will always be to some extent unexpected. Therefore risk management
methodologies will always need to be supplemented with resilience
methodologies if we are ever going to be able to reduce the impacts of
future disasters – bearing in mind that rapid increases in population,
development and commerce render society ever more vulnerable to nature’s
challenges,” Professor Davies says.