Geoscience Reference
In-Depth Information
who believe that they are in control of their life will
also take action to survive. In contrast, people who
are low-anxiety or fatalistic believe their lives are
controlled externally. This difference also relates to
variation in socio-cultural groups. For example, as
mentioned in Chapter 3, Sims and Baumann (1972)
found that there was a higher incidence of death due to
tornadoes in the south of the United States than in the
north. People in Alabama distrust the Weather Bureau
and its warnings. They await their fate and, as a result,
there is a greater incidence of death there because of
tornadoes. On the other hand, people in Illinois
believe they are in control of their own lives, are tech-
nologically orientated, and take precautions against the
threat of tornadoes. They better survive the risk as
a result.
For some, the decision to evacuate is an economic
one. Any evacuation costs money, no matter who orga-
nizes it or carries it out. An evacuation involves loss of
income for most of the community. For example,
fishermen in the Caribbean do not evacuate during
cyclones. Staying behind with their boat is more
acceptable than evacuating, knowing that it is going to
cost them money to move, and loss of income for the
time they have moved. Loss of income may be unac-
ceptable if your income is paying for an expensive
mortgage, or keeping you from the moneylender. In
that case, evacuation will be contemplated only if the
hazard is a certainty.
The 'cry wolf' syndrome lulls others. For example,
even though the residents of Darwin in 1974 had up to
three days' warning of the arrival of Cyclone Tracy,
only 30 per cent took precautions. This was because a
cyclone had approached Darwin in the previous week,
and had veered away. False cyclone threats are always
happening in Darwin. Tracy also had the misfortune of
occurring just before Christmas. Preparing for Tracy
meant interrupting Christmas celebrations for a
cyclone that might never come. Evacuation meant
going inland, where there were no facilities, and the
possibility of being trapped by heavy rains. Similarly,
in the United States, tornado warnings are ignored
because they are issued for very large areas, when their
probability of occurrence in part of that area is small.
The Weather Bureau assumes that the total population
will respond to a warning. However, so few people
have actually experienced a tornado that the majority
of the population fails to take any precautionary
measures. Civil defense groups in the United States
now make more dramatic pleas for evacuation. For
instance, after a newscaster has broadcast a tropical
cyclone warning in the weather report, the head of the
civil defense organization may interrupt further broad-
casting, identify who they are and, in an authoritative
voice, state that the cyclone threat is now real and
people should take immediate action to evacuate for
their own personal safety. Of course, this did not occur
before Hurricane Andrew made landfall in 1992.
There are also those who are quite willing to
evacuate, even though the signs of impending disaster
are not obvious to the public. Many people in touch
with nature, such as North American Indians, have left
areas of disaster weeks in advance, responding to subtle
signs shown by insects and animals. For example, some
Indians in the Mt St Helens area packed up and left
before the eruption, because they noticed animals
doing the same thing. Indian tribes in southern Califor-
nia have left flood-prone areas in the midst of drought,
because they noticed insects and ground burrowing
animals seeking higher ground. Several weeks later
flash flooding occurred when the drought broke.
Evacuation can also be dangerous. It may seem
advantageous to flee the landfall of an approaching
cyclone and, certainly - if warning is given of an earth-
quake - it is wise to leave buildings and head for open
spaces. The same type of evacuation might also seem
appropriate if a wildfire is swooping towards your
home at 20 km hr -1 , as happened in Australia's 1983
Ash Wednesday bushfires. However, a study by Wilson
and Ferguson (1985) of houses occupied at Mt
Macedon showed that it was better not to flee this
bushfire. Only 44 per cent of unattended houses
survived compared to 82 per cent of occupied houses.
This evidence was ignored during the devastating
bushfire that swept through Canberra 20 years later.
Six people lost their lives at Mt Macedon; however,
this could not be attributed to the fact that people
remained at home to fight the fires. Evacuation during
the fire was downright deadly. Other evacuees clogged
roads, smoke made driving impossible, and some cars
ended up trapped in exposed areas, where death from
heat radiation was a risk. Similarly, it is unwise to try to
flee approaching tornadoes in cars. Studies in the
United States have shown that 50-60 per cent of
deaths and injuries from tornadoes are caused by flying
glass from broken windscreens.
In some cases, where the disaster occurs suddenly,
evacuation may not be a viable option. During most
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