Basics of early warning
Hazards, vulnerability and disasters
Natural hazards, such as storms, droughts, volcanic eruptions, or earthquakes,
need not spell disaster. A disaster occurs only if a community or
population is exposed to the natural hazard and cannot cope with
its effects. Torrential rain in the middle of an ocean will not cause
a disaster, but the same heavy rainfall on a vulnerable population – say
a shanty town on the side of a hillside stripped of trees - may result
in landslides and a huge loss of life. A minor drought may cause
a famine if a region’s agricultural production is highly stressed
by civil war. A community that lacks an early warning system may
sleep while volcanic ash clouds bear down upon them. Vulnerability
is the potent additive that mixes with natural hazards to cause disasters.
More than just a prediction
A complete and effective early warning system comprises four elements,
spanning a knowledge of the risks faced through to preparedness to
act on early warning. Failure in any one part can mean failure of
the whole system.
The Four Elements of Effective Early Warning Systems
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| Risk knowledge |
Systematically collect data and
undertake risk assessments
Are the hazards and the vulnerabilities
well known? What are the patterns and trends in these factors?
Are risk maps and data widely available? |
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| Monitoring and warning service |
Develop hazard monitoring and early
warning services
Are the right parameters being monitored? Is
there a sound scientific basis for making forecasts? Can accurate
and timely warnings be generated?
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| Dissemination and communication |
Communicate risk information and
early warnings
Do warnings reach all of those at risk? Are the
risks and the warnings understood? Is the warning information
clear and useable |
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| Response
capability |
Build national and community response
capabilities
Are response plans up to date and tested? Are local
capacities and knowledge made use of? Are people prepared and
ready to react to warnings? |
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Pulling it all together
Good early warning systems have strong linkages between the four elements.
The major players concerned with the different elements meet regularly
to ensure they understand all of the other components and what other
parties need from them. Risk scenarios are constructed and reviewed.
Specific responsibilities throughout the chain are agreed and implemented.
Past events are studied and improvements are made to the early warning
system. Manuals and procedures are agreed and published. Communities
are consulted and information is disseminated. Operational procedures
such as evacuations are practiced and tested.
Behind all of these activities
lies a solid base of political support, laws and regulations, institutional
responsibility, and trained people. Early warning systems are established
and supported as a matter of policy. Preparedness to respond is engrained
in society.
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