1. Hazards Definitions And Characteristics

2. Definitions
Hazard: A threat (whether natural or human) that has the potential to cause loss of life, injury, property damage, socio-economic disruption, or environmental degradation.
Hazard Event: The occurrence (realization) of a hazard, the effects of which change demographic, economic, and/or environmental conditions.

3. Definitions
Disaster: A major hazard event that causes widespread disruption to a community or region, with significant demographic, economic and/or environmental losses, and which the effected community is unable to deal with adequately without outside help.
Vulnerability: The geographic conditions that increase the susceptibility of a community to a hazard or to the impacts of a hazard event.
Risk: The probability of a hazard event causing harmful consequences.

4. Geological/ Geomorphological
Types
Climatic/
Meteorological
Geological/ Geomorphological
Floral
Faunal
Snow and Ice
Avalanches
Fungal Diseases
Bacterial Diseases
Droughts
Earthquakes
Athlete’s Foot
Viral Diseases
Floods
Erosion (Soil and Coastal)
Dutch Elm Disease
Influenza
Frosts
Landslides
Wheat Stem Rust
Malaria
Hail
Shifting Sand
Infestations
Smallpox
Heatwaves
Tsunami
Hay Fever
Rabies
Tropical Cyclones
Volcanic Eruptions
Poisonous Plants
Lightning and Fires
Rabbits/Termites
Tornadoes
Venomous Bites

5. What Happens Where? (Some)
Tropical Storms
Earthquakes
Drought
Tornadoes
Active Volcanoes
Mexico
Colombia
Central USA
Japan
Iceland
West Indies
Gulf Of Mexico
N & S Africa
Australia
Antarctica
Kenya
Florida
Brazil
South Africa
Africa
Argentina
India
China
Peru
Afghanistan
Alaska
Germany
New Zealand
California
France
Indonesia
San Francisco
Spain
Los Angeles
Turkey
USA

6. Characterising Hazards
Magnitude: The size of the event e.g. Force 10 on the Beaufort Scale, Maximum Height or Discharge of a Flood, or the size of an Earthquake on the Richter Scale.
Frequency: How often an event of a certain size occurs. For example a flood 1m high may occur, on average, every year. By contrast in the same stream a flood of 2m might occur only every 10 years. The frequency is sometimes called the recurrence interval (Gumbel’s Laws). The larger the event, the less frequently it occurs. However it is the very large events that do most of the damage (to the physical environment, to people, properties, and livlihoods).

7. Characterising Hazards
Duration: The length of time that an environmental hazard exists. This varies from a matter of hours, such as with urban smog, to decades, in the case of drought, for example.
Areal Extent: The size of the area covered by the hazard. This can range from very small scale, such as an avalanche chute, to continental, as in the case of drought.
Spatial Concentration/Dispersion: Is the distribution of hazards over space; whether they are concentrated in certain areas, such as tectonic plate boundaries, coastal locations and valleys etc.

8. Characterising Hazards
Speed Of Onset: This is rather like the lag-time in a flood hydrograph. It is the time difference between the start of the event and the peak of the event. It varies from rapid events, such as the Kobe Earthquake, to slow time-scale events such as drought in the Sahel of Africa.
Regularity: (or temporal spacing). Some hazards, such as cyclones, are regular; whereas others, such as earthquakes and volcanoes, are much more random.

9. Activity 1 Look at the “Natural Hazards” Worksheet and…
Try to work out what type of hazard it is.
A place in the world it could happen.
Whether it is natural or human induced.

10. Activity 2
Look at the “What Is A Natural Hazard?” Worksheet and answer the following…
What would be your definition of an “Extreme Natural Event” and why?
What is a “Vulnerable Population” and what makes them vulnerable?
Explain the interaction/consequences of the interaction between an “Extreme Natural Event” and a “Vulnerable Population”.
Is the definition of a Natural Hazard justified? Is there anything that could be added?