1. UGRC 144 Science and Technology in Our Lives/Geohazards
Session 1 – Introduction to Hazards and Disasters
Lecturer: Dr. Patrick Asamoah Sakyi
Department of Earth Science, UG
Contact Information:

2. Session Overview
In everyday life, we always negatively associate events like earthquakes, tsunami and floods, with disasters.
In this section;
The terms disaster and hazard are defined and explained
Explanation will be given as to why the mere occurrence of an event like an earthquake should not be regarded as the occurrence of a disaster.
Also, the conditions under which an event becomes a disaster will be explained.

3. Session Outline
The key topics to be covered in the session are as follows:
Topic One - Hazard
Topic Two - Classification of Hazards
Topic Three - Vulnerability
Topic Four - Disaster
Topic Five - Disaster prevention and management

4. Reading List
Read Chapter 4 of Environmental Geology 4th Edition – by Carla W Montgomery (1995)
Read Unit 1, Section 1 of UGRC 140 II Geohazards – Institute of Continuing and Distance Education

5. Topic One
HAZARD

6. What is a Hazard Hazard is defined as:
Phenomena that pose a threat to people, structures, or economic assets and which may cause a disaster. They could be either man-made or naturally occurring in our environment.
A natural or man-made phenomenon that may cause physical damage, economic loss and threaten human life and wellbeing
A trigger event. A trigger-event that sets off a disaster
Hazard means an event which has the potential to cause a disaster, and can be either natural or man-made.

7. CLASSIFICATION OF HAZARDS
Topic Two
CLASSIFICATION OF HAZARDS

8. Classification of Hazards
Hazards are classified into two main groups, namely:
natural hazards and
man-made hazards.

9. Classification of Hazards
There are two types of natural hazards, namely;
fast-impact and
slow-onset hazards, (e.g. chemical spill, fire), or technological in nature (e.g. nuclear generator failure).
Examples of fast impact natural hazards include earthquakes, floods, cyclones, hurricanes, tornadoes, landslides, tsunami, volcanic eruption, insect infestation and wild-fires.
Slow onset natural hazards include epidemics of biological origin (e.g. SARS, Bird Flu, Ebola), drought, and famine.

10. Classification of Hazards
Man-made hazards are also of two types;
sudden
long term;
Sudden man-made hazards include transport, structural and technological accidents (e.g. chemical spill, fire)
Long term man-made hazards (e.g. nuclear generator failure).

11. Topic Three
VULNERABILITY

12. What is Vulnerability
Vulnerability is a term used to describe exposure to hazards and shocks.
It is defined as the extent to which a community, structure, service, and/or geographic area is likely to be damaged or disrupted by the impact of a particular hazard, on account of their nature, construction and proximity to hazardous terrain or a disaster prone area.
People are more vulnerable if they are more likely to be badly affected by events outside their control.
For a disaster to occur the hazard must come in touch with unsafe – conditions which make a population vulnerable to that particular hazard

13. Topic Four
DISASTER

14. What is a Disaster A disaster is;
A sudden, adverse event bringing great damage, loss, great distress, destruction and devastation to life and property.
A serious disruption of the functioning of society, causing a calamity, widespread human, material or environmental losses which exceed the ability of the affected society to cope using its own resources.
The disruption of human ecology that exceeds the capacity of the community to function normally (WHO).
Sudden ecologic phenomenon of sufficient magnitude to require external assistance

15. What does a Disaster do?
A disaster influences the mental, socio-economic, political and cultural state of the affected area.
It completely disrupts the normal day to day life in a society
It negatively influences the emergency systems
Normal needs and processes like food, shelter, health, etc. are affected and deteriorate depending on the intensity and severity of the disaster

16. DISASTER PREVENTION AND MANAGEMENT
Topic Five
DISASTER PREVENTION AND MANAGEMENT

17. How do we Prevent Disaster?
We now know that:
DISASTER = HAZARD + VULNERABILITY
Human-induced hazards that can potentially result in a disaster can be avoided or prevented
Naturally-occurring hazards cannot be entirely controlled, but disasters associated with them can be reduced by following certain directives.

18. How do we Prevent Disaster?
To avoid, prevent or manage a disaster;
Eliminate Hazard  No Disaster
Eliminate Vulnerability  No Disaster
Keep Hazard and Vulnerability Apart.
Reduce Vulnerability and/or hazard, especially human-induced hazard.
The specific disaster prevention and/or management techniques will be discussed under each geological hazard in subsequent sections

19. Summary In this section;
we have defined and explained; disaster, hazard and vulnerability.
We have seen that hazards only result in a disaster if they coincide with vulnerable conditions.
We have seen that to avoid a disaster, we must prevent a hazard from coming in contact with vulnerable societies.

20. END