Natural hazards and Natural disasters Essay
Natural hazards and Natural disasters
There is a difference between natural hazardsand natural disasters. A hazard is an event orobject that is a potential source of harm to a community.
A disaster occurs as the result of ahazardous event that dramatically affects a community.
There are six broad types of hazards:1. Atmospheric Ð for example, cyclones, hailstorms,blizzards or bushfires2. Hydrological Ð for example, flooding, waveaction or glaciers3. Geological Ð for example, earthquakes orvolcanoes4. Biological Ð for example, disease epidemicsand plagues5.Technological Ð for example, accidents, explosionsor hazardous materials6.Human Ð for example, war, crowd stampedeand terrorism.
The first four groupings are generally referredto as natural hazards and the last two as humanhazards. It should be noted that some naturalhazards are influenced by the actions andlocations of people. For example, the severity ofbushfires depends not only on the amount of fuelavailable or the strength and humidity of thewind. Humans influence bushfires through carelessnessin the use of ®re, inadequate preparationof their property in the event of a bushfire andpoor disaster planning.
Risk analysis is concerned with the chance of ahazardous event occurring and whether or not itcould result in a disaster. The map oppositeshows those areas of Australia that are vulnerableto the threat of natural disaster. It showsthat different types of hazards and disasters areprevalent in different parts of Australia. Forexample, cyclones located to the north of Australiaare associated with the warm tropicalocean; bushfires to the south of Australia areassociated with dry vegetation. People who moveto an area are usually aware if it is located in anatural hazard zone. For example, though Cairnsis subject to cyclones, the people of that communityhave decided that the benefits of living andworking there outweigh the risk factor.
ASSESSING THE RISK
Few Australian communities are free of the risk ofnatural disasters, but some are more vulnerablethan others. Vulnerability varies according to:· the location of the community and thehazardous event· the magnitude of the hazardous event· the potential amount of damage.
When disasters occur in unpopulated areas, peopleare rarely killed or injured, and the damage toproperty is small. However, when hazardous eventstake place in populated areas, a disaster can occur.
Managing hazardsEffective management of hazards requires thatindividuals, communities and governments:· prepare for hazards Ð for example, by clearingvegetation around homes in bushfire-prone areas· prevent hazards Ð for example, by avoidingestablishing settlements on flood plains· recognise and respond to hazards quickly sothey do not turn into disasters.
Emergency management procedures involvegathering information, pre-disaster planning,responding, recovery and reconstruction. A disasterinvolves the coordination of voluntaryorganisations (such as the State EmergencyService), charities (such as the Salvation Army),financial assistance and donations, and governmentsupport (such as the army).
Australia’s worst natural disasters· Cyclone: Cyclone Tracy, Darwin 1974 Ð65 deaths, 10 800 buildings destroyed,$4180 million cost· Hailstorm: Sydney 1999 Ð 1 death, 24 800buildings damaged, $2000 million cost· Bushfire: Ash Wednesday, Victoria andSouth Australia 1983 Ð 75 deaths, 2500buildings destroyed, $950 million cost· Earthquake: Newcastle 1989 Ð 13 deaths,50 000 buildings damaged, more than$4000 million cost· Landslide: Thredbo, 1997 Ð 18 deaths, 2buildings destroyed, $40 million cost http://www.naturalhazards.org/discover/index.htmlhttp://www.pdc.org/iweb/pdchome.htmlhttp://earthobservatory.nasa.gov/NaturalHazards/