classifying natural disasters comparing and analyzing natural disasters

Classifying Natural Disasters

Comparing and Analyzing Natural Disasters

What is a natural hazard or disaster?

Aspects of the physical world that have the potential to cause considerable harm to people.

Caused by natural forces rather than by human action

Can you think of any examples?

What is a natural hazard or disaster? The international Red Cross estimates

that on average over the past 25 years 138,000 people have been killed, 46,000 injured and more than 4 million left homeless each year by natural disasters

These figures do not include the recent tsunami in Asia (273,000) and Hurricane Katrina (1000)

What is a natural hazard or disaster?

Natural disasters often occur in those areas of the world which are heavily populated

Classifying Natural Disasters

Most common way of comparing natural disasters is to measure their impact by the loss of life, the number of injuries and the damage to property that these events cause

Classifying Natural Disasters

We can also measure these disasters by the strength or intensity of the event (for example the wind speed of a hurricane)

In addition, we classify natural disasters by the impact they have on human beings, by the regions in which they occur and their frequency

Classification System

We can classify natural disasters by the chief process or sphere in which it operates

Using this system of classification there are three categories

Classification System

Atmospheric HazardsCyclonic Storms (hurricane)TornadoSevere StormFloodingDroughtWildfireSevere Weather (hot/cold)

Classification System

Biological Hazards

Infectious Disease

Parasitic Disease

Insect Infestation

Plant Disease

Classification System

Geological Hazards

Slide (mud, land, rock)

Volcanic Activity

Earthquake

Avalanche

Tsunami (tidal wave)

Comparing and Analyzing Natural Disasters

Any specific natural disaster can be described by analyzing various factors that determine how great an impact it will have on people

This system recognizes six main factors

Comparing and Analyzing Natural Disasters

1) Frequency- how often is the event likely to happen

2) Duration- the length of time the event lasts

3) Extent- does it affect a wide area or region or a small one

Comparing and Analyzing Natural Disasters4) Speed of onset- happen quickly with no

warning and over quickly or build slowly before the peak period

5) Spatial dispersion- the area that is likely to be affected by a particular event

6) Temporal spacing- how hazards and disasters occur in time; are they random or do they occur within a cycle