Lesson 3 3. Rainfall-induced landslide are one of the
BASIC CONCEPT OF HAZARD most common geological hazards, occurring
over a wide range of spatial and temporal
Hazards - the potential for damage to man and his scales in mountainous landscapes
environment that may result from the occurrence
of natural events. 4. Rapid sediment movement
TYPES OF HAZARD 5. Subsidence is a gradual settling or
1. Natural Hazards- hazards that results from sudden sinking of the Earth’s surface.
earth’s natural processes (e.g. volcanic eruption,
earthquake) 6. Sinkhole are formed when the land
surface above collapses or sinks into the
2. Secondary Hazard- hazards that resulted or cavities or when surface material is carried
consequence of other hazards (e.g. landslides, downward into the voids
tsunamis, aftershocks, ash fall, fire, floods)
7. Impacts with space objects
3. Technological Hazards- man-made hazards (e.g.
radiation leaks, toxicity of land due to pesticides, Hydrologic Hazards is an extreme events
dynamite fishing, arson, toxic waste, deforestation, associated with water occurrence, movement, and
pollution) distribution, hydrological hazards include droughts
and flooding and related event
4. Quasi-natural Hazards- hazards that results 1. Floods
from the interaction of natural processes and 2. Wave action
human activities (e.g. smog, desertification, 3. Drought
landslides) 4. Rapid Glacier Avalanche
Atmospheric Hazards - air-related hazards
CLASSIFICATION OF HAZARD Typhoons or Hurricanes, Thunderstorm, Excessive
Geologic Hazards- an extreme natural events in rainfall, Tornadoes, Heavy snowfalls, Hail, Blizzards,
the crust of the earth that pose a threat to life and Glaze storm, Freezing rain, High wind speeds,
property. Extreme temperatures, Lightning
1. Earthquake-sudden and violent shaking
of the ground, sometimes causing great Biologic Hazards also known as biohazards, refer
destruction, as a result of movements to biological substances that pose a threat to the
within the earth’s crust or volcanic action. health of living organisms, primarily that of
• Vibrations humans. This can include medical waste or samples
• Ground Rapture of a microorganism, viruses, or toxins (from a
• Liquefaction biological source) that can affect human health.
• Earthquake-induced Landslide
• Tsunami 1. Epidemic in humans is an epidemic in
which the causal agent is transmitted from
2. Volcanic Eruption is when lava and gas person to person, allowing the epidemic to
are released from a volcano—sometimes propagate and spread as a function of Ro.
explosively. 1.1 Bubonic Plauge (Black Death)
• Lava Flow -black discoloration of the skin
• Volcanic Gas -fleece, parasite (1300 yrs ago)
• Pyroclastic flow -mice, rats
• Tephra Fall
• Lahar 1.2 Polio Virus
• Volcanic Debris
• Avalanche
BASIC CONCEPT OF HAZARD most common geological hazards, occurring
over a wide range of spatial and temporal
Hazards - the potential for damage to man and his scales in mountainous landscapes
environment that may result from the occurrence
of natural events. 4. Rapid sediment movement
TYPES OF HAZARD 5. Subsidence is a gradual settling or
1. Natural Hazards- hazards that results from sudden sinking of the Earth’s surface.
earth’s natural processes (e.g. volcanic eruption,
earthquake) 6. Sinkhole are formed when the land
surface above collapses or sinks into the
2. Secondary Hazard- hazards that resulted or cavities or when surface material is carried
consequence of other hazards (e.g. landslides, downward into the voids
tsunamis, aftershocks, ash fall, fire, floods)
7. Impacts with space objects
3. Technological Hazards- man-made hazards (e.g.
radiation leaks, toxicity of land due to pesticides, Hydrologic Hazards is an extreme events
dynamite fishing, arson, toxic waste, deforestation, associated with water occurrence, movement, and
pollution) distribution, hydrological hazards include droughts
and flooding and related event
4. Quasi-natural Hazards- hazards that results 1. Floods
from the interaction of natural processes and 2. Wave action
human activities (e.g. smog, desertification, 3. Drought
landslides) 4. Rapid Glacier Avalanche
Atmospheric Hazards - air-related hazards
CLASSIFICATION OF HAZARD Typhoons or Hurricanes, Thunderstorm, Excessive
Geologic Hazards- an extreme natural events in rainfall, Tornadoes, Heavy snowfalls, Hail, Blizzards,
the crust of the earth that pose a threat to life and Glaze storm, Freezing rain, High wind speeds,
property. Extreme temperatures, Lightning
1. Earthquake-sudden and violent shaking
of the ground, sometimes causing great Biologic Hazards also known as biohazards, refer
destruction, as a result of movements to biological substances that pose a threat to the
within the earth’s crust or volcanic action. health of living organisms, primarily that of
• Vibrations humans. This can include medical waste or samples
• Ground Rapture of a microorganism, viruses, or toxins (from a
• Liquefaction biological source) that can affect human health.
• Earthquake-induced Landslide
• Tsunami 1. Epidemic in humans is an epidemic in
which the causal agent is transmitted from
2. Volcanic Eruption is when lava and gas person to person, allowing the epidemic to
are released from a volcano—sometimes propagate and spread as a function of Ro.
explosively. 1.1 Bubonic Plauge (Black Death)
• Lava Flow -black discoloration of the skin
• Volcanic Gas -fleece, parasite (1300 yrs ago)
• Pyroclastic flow -mice, rats
• Tephra Fall
• Lahar 1.2 Polio Virus
• Volcanic Debris
• Avalanche
