Download Overview of the Natural Hazards Class 11-16-12

What do we learn in Natural Hazards Course?
Presenter: Dr. Yuri Gorokhovich, Lehman College
1. Concept of multi-hazard approach
2. Geographic Information Systems techniques
3. Making maps and working with digital data
Why Studying Natural Hazards Is Important?
As population continues to grow, hazards, disasters, and catastrophes
become more common.
Definitions of hazards, disasters and
catastrophes:
A natural hazard is any natural process
that poses a threat to human life or
property. Examples.
A disaster occurs when a hazard, such as
a flood or earthquake, inflicts loss of life
and property in over a limited time span in
a defined area. Examples.
A catastrophe is a massive disaster,
typically with many deaths, requiring a
large input of time and money to rectify.
Examples.
Acts of God
Acts of Man
Disaster stages and lessons:
1. Precursors: earthquakes, volcanic eruptions and other natural and
anthropogenic (wars, deforestation, etc.) influences
2. Early warning
3. Preparedness:
•
Directed operations, command, control
•
Education, scientific research and monitoring, building local capacity
4. Response:
•
Management and Planning
•
Building resilience, decrease vulnerability
5. Post-disaster recovery
6. Post-disaster analysis and conclusions:
•
Mitigation and prevention
Illustrated version:
http://www.youtube.com/watch?v=ya0sO5pxeZk
Global Distribution of Natural Hazards (1993-2002)
Role of Internal
and External (blue) processes
Source: WMO,
http://www.uncosa.unvienna.org/docs/iamos/2005/open_session_presentations/WMO_files/frame.htm#slide0138.htm
Geologic factors of Natural Processes
The rock cycle may be considered a worldwide earth-material recycling
process driven by Earth’s internal heat,
Driven by solar energy, the hydrologic cycle operates by way of evaporation,
precipitation, surface runoff, and subsurface flow.
Biogeochemical cycles can be described as the transfer of chemical elements
through a series of storage compartments or reservoirs, such as air or
vegetation.
The Tectonic Cycle
Hazards:
Volcanoes, Earthquakes;
Long - term: Climate change
Involves the creation, movement, and destruction of tectonic plates through geologic
process driven by forces deep within Earth.
The Hydrologic Cycle
Hazards:
Climate change, Hurricanes, Tornadoes, Floods, Droughts, Wildfires
Solar energy
drives
movement of
water
between
atmosphere
and oceans
and
continents.
Biogeochemical Cycles
Hazards:
Climate change, ecological disbalance
The major natural biochemical
cycles include the carbon,
nitrogen, and phosphate
cycles
Plants such as trees and
algae undergo the
photosynthesis reaction where
carbon dioxide and water in
the presence of sunlight are
converted to organic materials
and oxygen.
Fish use metabolism where
oxygen and organic materials
- other small fish or algae - as
food is converted to carbon
dioxide, water, and energy.
Bacteria in water, as well as land, also undergo metabolism and use oxygen and decompose organic
wastes as food to convert to carbon dioxide, water, and energy. By products in the decomposition of
organic waste are nitrates and phosphates.
Death and Damage Caused by Natural Hazards
Role of History in Understanding Hazards
1. A better understanding and more accurate prediction of natural processes come by
integrating historic and prehistoric information, present conditions, and recent past
events, including land-use changes.
2. Historical events provide the basis for preparedness
3. Current information collected by monitoring provides the basis for early warning
4. Historical analysis of majority of types of disasters shows that magnitude of a
hazardous event is inversely related to its frequency
Role of History in Understanding Hazards: Santorini
Volcanic Complex in Greece
Population: 13,600 people
Tourism adds 1,000,000 per year
Housing flourishes
Role of History in Understanding Hazards: Santorini Volcanic Complex
Periodicity of destructive events similar to Minoan eruption: 20,000 years
Minoan eruption (1640 BCE): no victims
Now: No emergency plan, no
coordination between emergency
response units. Training? Preparedness?
Possible eruption: similar to any postMinoan eruption
Possible outcome: ???? Why???
Climate Change Hazard:
Was Earth an “ice” or “hot house”?
Learning from historical data
http://www.scotese.com/climate.htm
Five fundamental concepts establish a philosophical
framework for studying natural hazards.
1. Hazards are predictable from scientific evaluation. However, this does not
include the prediction of exact time and geographic location.
2. Risk analysis is an important component in our understanding of the effects of
hazardous processes.
3. Linkages exist between various natural hazards as well as between hazards
and the physical environment. Multi-hazard concept.
4. Hazardous events that previously produced disasters are now producing
catastrophes.
5. Consequences of hazards can be minimized
Magnitude and Frequency of Hazardous Events
Cumulative number of events per year
Fatalities per event
Comparison of natural disaster fatalities in the United States. Cumulative size-frequency
distributions for annual earthquake, flood, hurricane, and tornado fatalities. In addition to
demonstrating linear behavior over 2 to 3 orders of magnitude in loss, these data group into
two families. Earthquakes and tornadoes are associated with relatively flat slopes (D=0.4 0.6); while floods and tornadoes have steeper slopes (D=1.3 - 1.4).
Source: Barton and Nishenko. Natural Disasters—Forecasting Economic and Life Losses. USGS Facts
Sheet. http://pubs.usgs.gov/fs/natural-disasters/index.html
Human Population Growth and its relation to Natural Hazards
Population growth has negative and
positive effects:
- Land use change; depletion of
resources; social disparity
- Intellectual development (do we use it
wisely ?) 
5. Consequences of Hazards Can Be Minimized
• Move from reactive response: Recovery and
restoration
• To an anticipatory response: Avoiding and adjusting
to hazards:
–
–
–
–
–
–
Land-use planning
Building codes
Insurance
Evacuation
Disaster preparedness
Artificial control
Benefits of Hazards
• Natural hazards have nature’s service function
• Examples:
– Flooding provides nutrients for soil.
– Landslides form dams to create lakes and habitat.
– Volcanoes create new land and enrich soil.
– Volcanoes contribute gases to the atmosphere and
produced first water on the planet.
– Hurricanes destroy old forest, enrich soil, replenish
aquifers
– Erosional processes (flooding, river erosion, etc.) help
enrich soil, provide mineral resources and sustains life