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Lecture 1

Introduction toNatural Disasters and Risk

John Rundle GEL 131 WQ 2014

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Topics for Today

• Outline of course• Discussion of expectations• Goals for the course and student learning• Course syllabus and outline of course• Risk: Definitions and other details• Types and examples of natural disasters• The four phases of all disasters• Urbanization and impact on populations• Vulnerability and demographics• Implications and future directions - discussion

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Expectations

• Homework (if assigned) should be handed in on time. Late homework will be penalized up to 1/3 of the total grade on that assignment

• Exams will be conducted at specific times and places (no makeups)

• Class participation is a major part of the grade• Cheating will not be tolerated, UCD policies will

apply• If group projects are assigned, all involved

students will get the same grade for the project

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Goals for the course

Students Will:

• Have an understanding of the meaning of risk, and how it is related to underlying phenomena and vulnerability

• Learn to use various types of web-based resources to understand and evaluate risk

• Learn how risk is currently mitigated and managed, and how population trends are increasing human exposure to natural events

• Acquire the tools necessary to educate themselves and others to increase personal safety, and to be able to interpret statements and policies promulgated by public officials.

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Course Syllabus

• Text: Patrick Abbot, "Natural Diasasters", any recent edition

• Go to Smartsite for course syllabus• Or: http://physics.ucdavis.edu/~rundle/GEO131/• Additional web sites:

– http://social.openhazards.com– http://www.openhazards.com– http://www.quakesim.org– http://www.wikipedia.org

...and many other sites...to be identified...

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Outline of Course

1.     Introduction: The concept of risk                                                           2.     Plate tectonics and earthquakes                                             3.   Tsunamis                                                          

4.    Volcanic Eruptions                                                          

5.    Weather: Tornados and severe storms                                                           6.     Hurricanes, typhoons, and tropical cyclones                                                           7. Floods                                                          

8.     Wildfires                                                          

9. Society and its response 10. Forecasting

11. Risk management and how it is currently practiced 12. The role of new technologies in managing and mitigating risk

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Definition of Risk

• We generally consider:

Risk = Hazard x Vulnerability

• Other definitions (http://en.wikipedia.org/wiki/Risk):

– Risk is the potential of loss (an undesirable outcome, however not necessarily so) resulting from a given action, activity and/or inaction.

– The notion implies that a choice having an influence on the outcome sometimes exists (or existed).

– Potential losses themselves may also be called "risks". – Any human endeavor carries some risk, but some are much riskier than

others.

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Other Measures of Risk(http://en.wikipedia.org/wiki/Risk)

• Statistical: The probability of something happening multiplied by the resulting cost or benefit if it does. (This concept is more properly known as the 'Expectation Value' and is used to compare levels of risk)

• Finance: The probability that an actual return on an investment will be lower than the expected return. (Also, due to high volatility in the markets)

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Risk Continued(http://en.wikipedia.org/wiki/Risk)

• Insurance: A situation where the probability of a variable (such as burning down of a building) is known but when a mode of occurrence or the actual value of the occurrence (whether the fire will occur at a particular property) is not.

• A risk is not:– An uncertainty (where neither the probability nor

the mode of occurrence is known)– A peril (cause of loss)– A hazard (something that makes the occurrence

of a peril more likely or more severe).

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Types of Financial Risk(http://en.wikipedia.org/wiki/Risk)

Financial risk can be divided into the following categories such as :

– Basic risk – Default risk– Exchange rate risk– Interest rate risk– Settlement risk

ImpactsLoss Trends (Munich Re, 2012)

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Disasters are increasing exponentially in time due to populations moving into at-risk areas.

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Exponential Growth(serc.carlton.edu)

• Birth and death processes are governed by exponential growth

• R = growth rate = B – D

• B = Birth rate• D = Death rate

The Four Phases of a Disaster

Disaster PhaseTypical Time

ScalesSolutions

Anticipation Months to DecadesScience:

Forecasting and Planning

Mitigation Months to YearsEngineering:

Structures and Lifelines

Response Seconds to Weeks Social, IT, Medical: Emergency Responders

Recovery Weeks to Years

Economics, Engineering: Finance and

Reconstruction

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Forecasting vs. Prediction

Context Characteristic

Prediction A statement that can be validated or falsified with 1 observation

ForecastA statement for which multiple

observations are required to determine a confidence level

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Fat-Tail Statistics

(Plotted on Log-Log Scales)

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Fatality Statistics (ca. 1993)http://pubs.usgs.gov/fs/natural-disasters/

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• 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). • Open symbols were not used to calculate slope of lines.

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Loss Statistics in $ (ca. 1993)http://pubs.usgs.gov/fs/natural-disasters/

• Plot of cumulative frequency of dollar loss due to earthquakes and hurricanes in the U.S. between 1900 and 1989.

• Data presented in this manner reveal linear trends which provide the basis for forecasting the probability of future dollar loss.

Hurricane Frequencyhttp://pubs.usgs.gov/fs/natural-disasters/

• The frequency of Florida hurricanes with wind speeds greater than or equal to 100 knots is mapped in terms of the probability of occurrence during a 20 year exposure window.

• These probabilistic estimates, based on 106 years of observations, illustrate that hurricanes with 100 knot winds occur more frequently in southern Florida, and gradually decrease in frequency towards northern Florida.

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World Population Trends(www.wikipedia.org/wiki/world_population; www.un.org;

http://www.census.gov/population/international/)

• World population estimates from 1800 to 2100, based on "high", "medium" and "low" United Nations projections in 2010 (red, orange, green)

• US Census Bureau historical estimates (black).

• Actual recorded population figures are in blue.

• According to the highest estimate, the world population may rise to 16 billion by 2100

• According to the lowest estimate, it may decline to 6 billion.

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World Population by Country – Most

Populous

http://en.wikipedia.org/wiki/World_population

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World population by continenthttp://en.wikipedia.org/wiki/World_population

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Current count of world population

http://www.census.gov/population/international/

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Urbanization Trends(www.un.org)

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The Worlds Megacities 2006http://en.wikipedia.org/wiki/World_population

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Growth in Megacities(www.famguardian.org)

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Developed vs. Developing Countries

(www.thecityfix.com)

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Urban vs. Rural Statistics(www.thecityfix.com; www.worldbank.org;

www.un.org)

• An advantage of cities is that most people are generally healthier

• They have higher incomes in general and live longer

• There are notable exceptions however

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The world is Increasingly at risk due to increasing vulnerability and exposure