Geography Reference
In-Depth Information
the Bhola cyclone of similar intensity in 1970 which led to the deaths of perhaps a
half a million people in the same region. The enormous difference in death tolls has
been attributed to the addition of many risk-reduction policies, such as: storm warn-
ing systems which gave people time to prepare for the storm; community disaster-
risk committees to identify and create local emergency responses; the maintenance,
clearing and deepening of drainage ditches; the construction of elevated cyclone
shelters in which approximately 2 million people took refuge; effective plans that
ensured the evacuation of 3.2 million people from the most at-risk areas in 2007
(Bray et al.
2008
). Although supported by the national government many of these
risk reduction policies were developed with the assistance—technical, social and
financial—of international advisers and organizations. Yet the cyclone still led to
the loss of over 2 million acres of crop land and 1.2 million livestock, devastating
the livelihoods of many farmers and leading to food shortages and price increases,
especially in cities.
These examples show some of the ways in which risk reduction policies have
led to improvements in the level of resilience to the threats posed by natural hazards
in settlements. In more specific terms it is helpful to look at the range of possible
measures in two contexts, the physical and the human domains. In the former con-
text there are five main categories in which improvements often need to be made,
namely, early warning systems, priority buildings, building codes, infrastructures
and policies that work with nature.
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Early Warning Systems
Increasing knowledge of the mechanisms of natural processes now provide earlier
warnings of the possible onset of many extreme natural events. Some people in
traditional societies had better skills than the modern population in living off the
land, anticipating the arrival of major storms, either by better sensing of weather
patterns or through knowledge of previous extreme events, passed on through the
generations that lived in the same area. This often led them to secure their dwell-
ings in advance of storms, or to move to higher ground before the arrival of floods
or tsunamis. Today, advances in the scientific knowledge of the mechanisms that
create natural hazards and the areas they will affect—combined with rapid com-
munication of the results through modern satellite and computer linkages in the
past three decades—has vastly increased our ability to show the size and places
of impact of many impending natural weather events. In the case of major storms,
tornadoes, excessive rain or hail, satellite coverage as well as networks of weather
stations regularly identify the start and progress of these hazards. It is now routine in
some countries to broadcast emergency warnings of impending storms by sirens and
by breaking into all radio and television channels, while in America alerts are also
made via social media sites such as Twitter and through mobile phones. Increas-
ingly early warnings often give days of preparation to areas that will be affected by
a storm, allowing residents time to stabilize or strengthen roofs, sandbag entrances,
add shutters to cover windows, to take shelter, or in case of really large storms
