1. What do we learn in Natural Hazards Course?
Presenter: Dr. Yuri Gorokhovich, Lehman College
Concept of multi-hazard approach
Geographic Information Systems techniques
Making maps and working with digital data

2. Why Studying Natural Hazards Is Important?
As population continues to grow, hazards, disasters, and catastrophes become more common.
Acts of God
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 Man

3. Disaster stages and lessons:
Precursors: earthquakes, volcanic eruptions and other natural and anthropogenic (wars, deforestation, etc.) influences
Early warning
Preparedness:
Directed operations, command, control
Education, scientific research and monitoring, building local capacity
Response:
Management and Planning
Building resilience, decrease vulnerability
Post-disaster recovery
Post-disaster analysis and conclusions:
Mitigation and prevention
Illustrated version:

4. Global Distribution of Natural Hazards (1993-2002)
Role of Internal and External (blue) processes
Source: WMO,

5. 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.

6. 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.

7. The Hydrologic Cycle
Hazards: Climate change, Hurricanes, Tornadoes, Floods, Droughts, Wildfires
Solar energy drives movement of water between atmosphere and oceans and continents.

8. 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.

9. Death and Damage Caused by Natural Hazards

10. Role of History in Understanding Hazards
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.
Historical events provide the basis for preparedness
Current information collected by monitoring provides the basis for early warning
Historical analysis of majority of types of disasters shows that magnitude of a hazardous event is inversely related to its frequency

11. Role of History in Understanding Hazards: Santorini Volcanic Complex in Greece
Population: 13,600 people
Tourism adds 1,000,000 per year
Housing flourishes

12. 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 post-Minoan eruption
Possible outcome: ???? Why???

13. Climate Change Hazard:
Was Earth an “ice” or “hot house”?
Learning from historical data

14. Five fundamental concepts establish a philosophical framework for studying natural hazards.
Hazards are predictable from scientific evaluation. However, this does not include the prediction of exact time and geographic location.
Risk analysis is an important component in our understanding of the effects of hazardous processes.
Linkages exist between various natural hazards as well as between hazards and the physical environment. Multi-hazard concept.
Hazardous events that previously produced disasters are now producing catastrophes.
Consequences of hazards can be minimized

15. Magnitude and Frequency of Hazardous Events
Fatalities per event
Cumulative number of events per year
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= ); while floods and tornadoes have steeper slopes (D= ).
Source: Barton and Nishenko. Natural Disasters—Forecasting Economic and Life Losses. USGS Facts Sheet.

16. 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 ?) 

17. 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

18. 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