Introduction to Hazards & Disasters
(DRR1141)
DR. M.E. MUGARI
Department of Geography and Environmental Sciences
Ephias.Mugari@univen.ac.za | Office#: FL-04
Twitter: @EphiasMugari | Skype: ephias.mugari | LinkedIn: Ephias Mugari, PhD
COURSE AIM: To introduce leaners to definitions and concepts
to perform hazard identification and assessment.
COURSE OBJECTIVES:
 Define key concepts
 Identify different hazards and perform hazard assessment.
 Explore and understand hazards, risks, and disasters in the
society and to be able to prevent it and reduce the impact on
people’s lives.
 Develop capabilities in hazard assessment.
MODULE 1
INTRODUCTION & DEFINITION OF KEY
TERMS
SOME KEY TERMS & CONCEPTS
• Hazards (Natural vs.
Anthropogenic)
• Disasters (Natural vs.
Anthropogenic)
• Accidents
• Emergencies
• Crises
• Catastrophes
• Calamities
• Anthropogenic
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Social construction of disasters
Vulnerability
Risk
Exposure
Spatial Aspects
Temporal Aspects
Pervasive/Creeping Events
Short Fuse Events
Resistance
Resilience
Processes that shape and
change the environment
What processes shape and change our environment?
a. Plate tectonics
b. Atmospheric processes
c. Human activities
d. Biological accumulation
a. Plate tectonics
● Process that results in the
formation of mountains, rivers,
oceans and volcanic eruptions.
b. Atmospheric processes
● Everything happens in the
atmosphere.
● Result in the formation of clouds,
precipitation, wind.
c. Human activities
● Urbanization (from growing human
population), extraction of
resources (e.g. mining and
logging), geoengineering (a type
climate intervention to mitigate the
impacts of global warming)
d. Biological engineering
● Reef building (coral larvae
attaches to a rock or any surface
where corals grows), colony
formation (growth in numbers of
organisms), forestation
(establishment of forest growth)
Hazards and Disasters
• What is a hazard?
• What is a disaster?
• What are the differences between hazards and disasters?
• What are the similarities between hazards and disasters?
Hazards
• A hazard is a dangerous phenomenon, substance, human activity or condition
that may cause loss of life, injury or other health impacts, property damage,
loss of livelihoods and service, social and economic disruption, or
environmental.
• It is any phenomena that has potential to cause destruction to life and property.
• Hazards pose a threat to our lives and are part of life on earth. They cannot be
avoided completely.
Hazards
• Based on their severity and place of occurrence, hazards can be classified as
disasters or not.
• Therefore, it can be assumed that hazard can also be a precursor to a disaster.
• Hazards become disasters when the potential to cause destruction is fulfilled.
• Necessary precautions to avoid dangerous results can be taken before a
hazard aggravates into a disaster e.g. taking appropriate disaster management
steps.
Disasters
• When there is harm to life and property, a hazard is termed a disaster.
• A disaster is a serious disruption of the functioning of a community or society
involving widespread human, material, economic, or environmental losses and
impacts which exceeds the ability of the affected community or society to cope
using its own resources.
• Therefore, disasters are occurrences that completely disrupt the normal life
pattern of victims.
Disasters
• A disaster is a degree of a hazard that has become more threatening.
• A disaster has more negative consequences than a hazard.
• In brief, a disaster is more catastrophic in nature.
• Furthermore, unlike a hazard, a disaster is more sudden and thus severe.
HAZARD
DISASTER
A dangerous
A serious disruption of a
phenomenon, substance
community or society
or condition e.g.
bombings, typhoons,
chemical leakages
State of Emergency
Similarities between hazards & disasters
• Both bear potential threat to humans since each can result in loss and damage
to life and property.
• Both can cause dangerous results to the affected victims.
• Both hazards and disasters can be natural or man-made.
Differences between hazards & disasters
• The main difference is that a hazard is a dangerous situation or event that
poses a threat to humans while disaster is an event that actually harms human
life, property and thus disrupts social activities.
• A disaster has more negative consequences, unlike a hazard.
• Disaster is a degree of a hazard that has become more threatening.
• A disaster is more sudden than a hazard.
Differences between hazards & disasters
• Thus, a disaster can be defined as an occurrence that completely disrupts the
normal life pattern of victims.
• In brief, a disaster is more catastrophic in nature.
• Furthermore, unlike a hazard, a disaster is more sudden and thus severe.
• Hazards do not necessarily cause any destruction. If an earthquake hits a
barren mountain with no human community, it is simply a natural phenomenon;
• NB: All disasters are hazards, but not all hazards are disasters.
Differences between hazards & disasters
• Definition: Hazard is a dangerous situation that poses a threat to human life while disaster is
an event that completely causes damage to human life and property.
• Degree: Disaster has more critical consequences when compared to the threats to the humans
from a hazard. Therefore, disaster is more catastrophic in nature than a hazard.
• Occurrence: Disaster happens most often in a short time, thus making more severe while
hazard will take its full shape after a series of events, which might have led it to happen.
Therefore, necessary precautions can be taken to avoid the negative consequences of a
hazard.
Hazard and Disaster Classification
Major Categories/Types
1. Natural Hazards – also called physical hazards
2. Anthropogenic Hazards – also termed man-made or human-induced
 Anthropogenic Non-intentional Hazards
 Anthropogenic Intentional Hazards
Natural Hazards & Disasters
• Naturally-occurring phenomena caused by either rapid or slow onset of events.
• Occur naturally i.e. without direct human interference e.g. thunderstorms.
• Natural (or physical) events are only termed hazards when they have potential
to harm people or cause property damage, social and economic disruption.
• Location of natural hazards primarily depends on natural processes e.g.
movement of tectonic plates, influence of weather systems, and existence of
waterways and slopes (e.g. that might generate landslides).
Natural Hazards & Disasters
• However, human activities such as urbanization, environmental degradation
and climate change can also influence the location, occurrence (frequency)
and intensity of natural hazards.
• These processes are known as risk drivers.
• The classification schemes for natural hazards vary across different research
institutions and governments, but these can be divided into:
Categories of Natural Hazards
• Meteorological (Atmospheric)
• Geological or geophysical (Earth)
• Hydrological (Water)
• Extraterrestrial
• Biological
• NB: Some are often combined i.e. Hydrological + Meteorological =
Hydrometeorological
Meteorological Hazards
• Meteorological hazard: a hazard caused by short-lived, micro- to
mesoscale extreme weather and atmospheric conditions that last from
minutes to days.
• Examples: Tropical cyclones; Thunderstorms; Tornadoes; Lightning;
Hailstorms; Windstorms; Snowstorms; Cold waves; Heat waves;
Avalanches; Fog; Frost
• Climatological hazard: a hazard caused by long-lived, meso- to macroscale atmospheric processes ranging from intra-seasonal to multidecadal climate variability.
• Examples: long-term climatic change
Geological Hazard
• Geophysical hazard: a hazard originating from internal earth processes.
• This term can be used interchangeably with the term geological hazard.
• Examples: Earthquakes; Volcanic activity and emissions; Landslides;
Subsidence; Mudflows; Mass movements; Landslides; Rockslides.
• Hydrometeorological factors are key contributors to some of these processes.
• Tsunamis are difficult to categorize: triggered by undersea earthquakes but
become an oceanic process that manifests as a coastal water-related hazard.
• An example of a geological hazard: China: Cascading down the mountain
Hydrological Hazards
• Hydrological hazard: a hazard caused by the occurrence, movement, and
distribution of the surface and subsurface freshwater and saltwater.
• Examples: Floods; Droughts; Wildfires
Hydrometeorological Hazards
• Are of atmospheric, hydrological or oceanographic origin.
• Examples are tropical cyclones (i.e. typhoons and hurricanes); floods, including
flash floods; drought; heatwaves and cold spells; and coastal storm surges.
• Hydrometeorological conditions may also be a factor in other hazards such as
landslides, wildfires, epidemics and transportation of toxic substances.
• An example of a hydrometeorological hazard: Climate change causes
landfalling hurricanes to stay stronger for longer
Extraterrestrial Hazards
• Extraterrestrial hazard: a hazard caused by asteroids, meteoroids, and comets
as they pass near earth, enter the earth’s atmosphere, and/or strike the earth,
or change in interplanetary conditions that affect the earth’s magnetosphere,
ionosphere, and thermosphere.
• Examples: Meteorites; Asteroids
Biological Hazards
• Biological hazard: a hazard caused by the exposure to living organisms,
including pathogenic microorganisms, bacteria, viruses, parasites, venomous
wildlife and insects, poisonous plants, and/or the toxic substances or vectorborne diseases that they may carry.
• Examples: Diseases; Epidemics; Pandemics (Covid-19); Overpopulation;
Famine
• An example of a biological hazard: A room, a bar and a classroom: how the
coronavirus is spread through the air
Anthropogenic Hazards & Disasters
• Also called human-induced or man-made i.e. occur due to human interference.
• Hazards originating from technological or industrial conditions, including
accidents, dangerous procedures, infrastructure failures, or specific human
activities.
• Other examples include road accident, oil spills, forest fire, industrial pollution.
• Can also be caused by rapid or slow onset of events.
Anthropogenic Hazards & Disasters
• Anthropogenic hazards are on the rise in recent years and are even more than
natural hazards.
• Anthropogenic hazards can non-intentional or intentional.
•
Anthropogenic Non-Intentional
• Technological
• Hazardous Materials
• Environmental
• Industrial
• Mining
• Nuclear
• Transportation
• Structural
Technological
• Acts of People
• Technological systems that fail because of complexities and human fallibility
(accidents)
Hazardous Materials
• Can classify in different categories
Environmental
• Can classify in different categories
Industrial
• Factories
• Refineries
Mining
• Coal
• Safety Standards
Nuclear
• Power plants
• Industrial use
• Medical use
Transportation
• Aviation
• Highways
• Railroads
• Maritime
Structural
• Fires
• Collapse
Anthropogenic Intentional Hazards
• Mass Shootings
• Civil Disobedience
• Terrorism
• Weapons of Mass Destruction
Mass Shootings
• School shootings
• Workplace violence
• Hate crimes
Civil Disobedience
• Labor riots
• Race riots
• Political riots
Terrorism
• State/State Sponsored
• International Non-state
• Domestic
Weapons of Mass Destruction
• Explosives
• Chemical
• Biological
• Nuclear/Radioactive material
Class Activity: Classify the following hazards
• Tornado
• Industrial pollution
• Landslide
• Heat wave
• Flood
• Typhoon
• Indoor fire
• Forest fire
• Lava flow
• Storm surge
• Covid-19 pandemic
• Tsunami
• Drought
• Extreme rainfall
Hint 1: Is it a natural or anthropogenic? Once you do that, which sub-category does it belong to?
Hint 2: One hazard may belong to more than one class.