'Disaster management' is better split up in two: 'disaster prevention' and 'emergency management". By definition, disasters cannot 'be managed'. One prevents a disaster and manages an emergency. Emergency management (EM) deals with all activities from preparedness to rehabilitation. Recovery goes from impact to reconstruction. Risk reduction goes from reconstruction to preparedness. Relief is all what is on the right side of the cycle while development is all what is on the left side.
Mitigation and Prevention are used as synonymous. Some expert prefers to drop the term Mitigation and use only Prevention. Mitigation means to reduce the severity of the human and material damage caused by the disaster. Prevention is to ensure that human action or natural phenomena do not result in disaster or emergency. Primary prevention is to reduce - avert - avoid the risk of the event occurring, by getting rid of the hazard or vulnerability. For example, primary prevention is to avoid overcrowding, deforestation and to provide services: healthier people in a healthy environment will be less vulnerable to most hazards; immunizing people against smallpox made them less vulnerable to the virus, and slowly eradicated the disease. Secondary prevention means to recognize promptly the event and to reduce its effects, that is, by staying alert to possible displacements of population; by being ready to provide immunization, food, clean water, sanitation and health care to refugees: healthier people in a healthy environment will also be more capable to overcome the emergency.
Preparedness includes all the measures that can ensure an effective relief. It stresses a safe environment: relief must not cause secondary risks to others and to oneself. 'Don't Make Things Worse' must be the guiding principle in preparedness for disasters. Response includes on the other hand all activities that can tackle an emergency. Other terms that are widely used are relief and humanitarian assistance, but they have slightly different meanings. Response means more than relief, which usually targets immediate and short-term needs. Humanitarian assistance includes certain aspects of protection and promoting, disseminating humanitarian laws and aspects.
Rehabilitation is restoring the basic function; and reconstruction is restoring to full resumption. In disaster management, the two are important, especially for people who cannot afford either.
Although predictions are quite possible as to the nature of weather and climate, and even to a certain extent, hazards and disasters, it is rather difficult to predict accurately the disasters that occur periodically on the surface of the earth. Hence, the people and communities vulnerable to disasters must helped and the first ever help we may render is the warning. The warnings must be comprehensive as to include the following activities:
= Identify location where a hazardous event will likely occur.
= Determine probability that an event of a given magnitude will occur.
= Mitigate, Anticipate, Prepare.
= Observe precursor events.
= Forecast the event.
= Warn the public.
There is a gap in the knowledge gained by hazards researchers and that of emergency planners and the general public. Why? It is because:
= Public are largely uneducated scientifically;
= Difficulty in communicating in a language, the general public can comprehend;
= Economic issues (lack of tourism if volcano expected to blow); and
Towards determining human response to disasters, it is necessary to assess risk and, once assessed, use the understanding arising out of it to develop strategies for averting the disaster. As we have seen before, if people are prepared, know how to respond to it, then half the risk is eliminated. The other half can be eliminated by being prepared for meeting the risk headlong. Rehabilitation and reconstruction will entail the risk assessment. Risk assessment is made using / considering the following logic.
= Risk determination = probability event occurs x consequences should it occur (risk = hazard + exposure).
= Acceptable risk assessment.
= Problems and opportunities for risk assessment in a commu-nity context.
Emergency Management: Emergency management actually deals with hazards in four phases:
= Mitigation - Minimizing the damage hazards can cause.
= Preparation - Tasks performed immediately before disaster occurs.
= Response - Actions taken after the disaster has occurred.
= Recovery - Repairing the damage, leads into mitigation, and makes a cycle.
A few days before a disaster, a Columbian geology student, Jos' Luis Restrepo, had come to Armero on a field trip. After playing billiards, he was returning to his hotel at about 10:50 p.m., when the lahar arrived. His recollection of events was recorded as follows by Dr. Barry Voight:
We didn't hear any kind of alarm, even when the ash was falling and we were in the hotel . . . we turned on the radio . . . The mayor was talking and he said not to worry, that it was a rain of ash, that they had not reported anything from the Nevado and to stay calm in our houses. There was a local radio station and we were listening to it, when suddenly it went off the air . . . about fifteen seconds later, the electric power went out and that's when we started hearing the noise in the air, like something toppling, falling, and we didn't hear anything else, no alarm .
The priest from Armero had spoken on a loudspeaker (around 6:00 p.m.) and had said the same thing: that there was no need to leave Armero . . . When we went out, the cars were swaying and running people down . . . there was total darkness, the only light was provided by cars . . . we were running and were about to reach the corner when a river of water came down the streets . . . we turned around screaming, towards the hotel, because the waters were already dragging beds along, overturning cars, sweeping people away . . . we went back to the hotel, a three-storey building with a terrace, built of cement and very sturdy . . .
Suddenly, I heard bangs, and looking towards the rear of the hotel I saw something like foam, coming down out of the darkness
. . . It was a wall of mud approaching the hotel, and sure enough, it crashed against the rear of the hotel and started crushing walls . . .
. And then the ceiling slab fractured and . . . the entire building was destroyed and broken into pieces. Since the building was made of cement, I thought that it would resist, but the boulder-filled mud was coming in such an overwhelming way, like a wall of tractors, razing the city, razing everything . . . .
Then the university bus, that was in a parking lot next to the hotel, was higher than us on a wave of mud and on fire, and it exploded, so I covered my face, thinking this is where I die a horrible death . . . There was a little girl who I thought was decapitated, but . . . her head was buried in the mud . . . A lady told me, 'look, that girl moved a leg'. Then I moved toward her and my legs sank into the mud, which was hot but not burning, and I started to get the little girl out, but when I saw her hair was caught, that seemed to me the most unfair thing in the whole world.