CHAPTER 3: HAZARDOUS ENVIRONMENTS

Question 1

What is a hazard?

Answer 1

It is an event that threatens, or actually causes damage and destruction to people their property and settlements.

Question 2

What is a natural hazard?

Answer 2

A natural hazard is one produced by environments process such as storms, floods, earthquakes and volcanic eruptions.

Question 3

Why are some places are more hazardous than others?

Answer 3

.Some places experience more than one type of natural hazards events
. Some places experience natural hazards more frequency than others
. In some places the hazards are stronger and more destructive than in others
. Some places are better able to cope with the damaging impacts of natural hazards

Question 4

What are the four main Hazard categories ?

Answer 4

.Geological
.Climatic
.Biological
.Technological

Question 5

What are the Hazards created by people (Technological) ?

Answer 5

.Nuclear explosion
. Pollution
. Transport accident
. Industrial explosions

Question 6

Important point

Answer 6

The important point to remember is that if there were no people there would be no natural hazards - just natural events.

Question 7

What are the events created by Geological Hazards ?

Answer 7

. Earthquakes
.Volcanic eruptions
.Landslides

Question 8

What are the events created by Climatic Hazards?

Answer 8

.Storms
.Floods
.Droughts

Question 9

What are the events created by Biological Hazard ?

Answer 9

.Fires
.Pests
.Diseases

Question 10

What is Geological Hazards ?

Answer 10

It is when all the events happening in the crust of the earth for example Tsunamis, Volcanos, earthquakes.

They can also be very destructive and aggressive causing damage and harm towards the people , buildings and surroundings.

Question 11

What is Climate Hazards ?

Answer 11

They are the hazards which threatens the health of any organism, known as biological hazard.

They can cause events such to can cause disasters to humans and their settlements due to climatic (weather) factors and change for example floods, Droughts, storms and tropical cyclones.

Question 12

What is Biological Hazards ?

Answer 12

Biological Hazards are formed to affect an organism health for example diseases such as cold, flu, malaria , dengue etc and even caused through pests and diseases.

Question 13

Causes of floods ?

Answer 13

• They are not only caused by heavy rainfall of a tropical cyclone.
• where as a stream of volcanic lava running down the valley can
  easily block the river can cause flooding upstream.
• Floods in the costal area can caused by tilde waves, for example
  tsunamis associated with earthquakes.
• storm surges can be caused by flooding.

Question 14

What are the natural events caused by indirect Hazards ?

Answer 14

• Droughts becomes hazards mainly because of its effect on food
  production.
• Crops and livestock which lack water will not yield so much food.
• Food shortages mean malnutrition and possibly death by
  starvation.

Question 15

Are diseases natural events or are they caused by humans?

Answer 15

• Malaria is a ‘vector’ or biological hazard carried from humans to the
  next by a mosquito.

There many contagious diseases associated with human pollution of the environment. (Typhoid and cholera are just two examples.)

• An interesting aspect of all disease is that hazard threat is very focused on people. The outcomes are illness and death for people.
• Tropical cyclones are a climate hazard in which two weather elements, wind and rain, threaten human life and property.
• Earthquakes and volcanic eruptions are geological or tectonic hazards.

Question 16

How does Tropical cyclones starts?

Answer 16

• A tropical cyclone starts when high temperatures cause air to rise
  from the surface of the sea.
• The rising causes local thunderstorms.
• Occasionally these small storms come together and create a
  strong flow of warm.
• Later air would rapidly rise.
• Producing an area increasingly low pressure.

(refer the diagram in pg 67)

Question 17

What are the number conditions that have to be met if these local thunderstorms are to be developed ?

Answer 17

-A deep layer of humid with warm and unstable air (>27 degrees)
- a supply of energy from the surface of the sea (the energy would
have to be heat and moisture)
-The sea must be at its warmest
- A circulatory motion of air (anti- clockwise in the northern
hemisphere encourage by the Coriolis force )
- Small changes in the wind speed and directions with increasing
altitudes. (encourages the circulatory motion within the cyclone)

Key word : Coriolis force - (its when the force created by the earths rotation that deflects any object moving at the earth surfaces.)

Question 18

What are the physical features of a cyclone ?

Answer 18

• it rotates vigorously upwards in the spiral of humid.
• warm air at its very center of its eye.
• There is an area of subsiding air with calm conditions and clear
  skies.
• Surroundings the eye is the eye wall, where the most destructive
  energy of the cyclone occurs.

Question 19

What is the global distribution of tropical cyclones?

Answer 19

STUDY FIGURE 3.4 IN PG 68