Learning Objectives Explain the difference between a disaster and a catastrophe. Discuss the role of history in the understanding of natural hazards. Discuss the components and processes of the geologic cycle. Apply the scientific method to a natural hazard of your choice.

Learning Objectives, cont. Synthesize the basics of risk assessment. Explain how much of the damage caused by natural hazards is often related to decisions people make before, during, and after a hazardous event. Explain why the magnitude of a hazardous event is inversely related to its frequency.

Learning Objectives, cont. Summarize how natural hazards are linked to one another and to the physical environment. Give reasons why increasing population and poor land-use practices compound the effects of natural hazards and can turn disasters into catastrophes. Explain how events we view as hazards provide natural service. Summarize links between climate change and natural hazards.

Earthquake in Haiti, 2010: A Human-Caused Catastrophe? Haiti recognized as an environmental catastrophe waiting to happen What were once disasters are now catastrophes due to increasing population and poor land-use choices Haiti’s population increased dramatically in recent decades About 90 percent of country deforested Island venerable to hurricanes and other high-intensity storms as well as earthquakes Four hurricanes and tropical storms hit the island within a month’s time two years before the earthquake

Deforestation in Haiti

Earthquake in Haiti, 2010: A Human-Caused Catastrophe? Earthquake became a catastrophe Eighty-five percent of people in Port-au-Prince lived in slum conditions Poor conditions lead to 190,000 destroyed or damaged Killed a quarter million people Two million homeless with poor sanitation and water quality Reason for catastrophe was clear: heavy human footprint Large number of poorly constructed buildings Population grew so fast

Collapsed Buildings in Haiti

1.1 Why Studying Natural Hazards Is Important Have experienced large, costly, and deadly natural hazards since 1995 Deadliest tsunami caused by earthquake in Indian Ocean Tsunami in Japan caused by largest and costliest earthquake in recorded history Catastrophic flooding in different areas of the world Volcanic eruptions that shut down international airports Worst tornado outbreak in U.S. history Etc.

Processes: Internal and External Physical, chemical, and biological ways in which events affect Earth’s surface Internal processes come from forces within Earth Plate tectonics Result of internal energy of Earth External processes come from forces on Earth’s surface Atmospheric effects Energy from the Sun

Hazard, Disaster, or Catastrophe Natural process or event that is a potential threat to human life or property Disaster Hazardous event that occurs over a limited time in a defined area Criteria: Ten or more people killed 100 or more people affected State of emergency is declared International assistance is requested Catastrophe Massive disaster that requires significant amount of money or time to recover

Major Hazards in the United States

Hazard, Disaster, or Catastrophe, cont. During past half century, there has been a dramatic increase in natural disasters (Figure 1.6a): Examples: Haitian earthquake, Indonesian tsunami, Hurricane Katrina United Nation: 1990’s “International Decade for Natural Hazards Reduction” Mitigation Reduce the effects of something Natural disaster preparation

Numbers, Effects, and Causes of Worldwide Natural Disasters

Death and Damage Caused by Natural Hazards Effects of hazards can differ and change with time because of changes of patterns of human land use Natural hazards that cause the greatest loss on human life may not cause the most property damage Hazards vary greatly in their ability to cause catastrophe

Potential for Humans to Influence Selected Natural Hazards in the United States

1.2 Role of History in Understanding Hazards Natural hazards are repetitive History of an area gives clues to potential hazards Maps, historical accounts, climate and weather data Rock types, faults, folds, soil composition

1.3 The Geologic Cycle Geologic conditions govern the type, location, and intensity of natural processes Collectively, processes are called geologic cycle Subcycles: Tectonic cycle Rock cycle Hydrologic cycle Biogeochemical cycle

The Tectonic Cycle Refers to large-scale processes that deform Earth’s crust and produce landforms Driven by forces within Earth Involves the creation, destruction, and movement of tectonic plates

The Rock Cycle Rocks are aggregates of one or more minerals Recycling of earth materials and linked to all other cycles Tectonic cycle: heat and energy Biogeochemical cycle: materials Hydrologic cycle: water for erosion and weathering Rocks classified according to how they were formed in the rock cycle

The Rock Cycle, cont. Igneous rocks Sedimentary rocks Form from crystallization of magma Sedimentary rocks Rocks are weathered into sediment by wind and water Deposited sediment undergoes lithification Metamorphic rocks Rocks are changed through extreme heat, pressure, or chemically active fluids

The Rock Cycle

The Hydrologic Cycle Movement of water between atmosphere and oceans and continents driven by solar energy Processes include: evaporation, precipitation, surface runoff, and subsurface flow Water is stored in compartments such as oceans, atmosphere, rivers, stream, etc. Residence time is estimated average time that a drop of water spends in any compartment Only a small amount of water is active at any given time

Hydrologic Cycle

The World’s Water Supply (Selected Examples)

Biogeochemical Cycles Transfer of chemical elements through a series of reservoirs Related to the three previous cycles Tectonic cycle: water from volcanic processes; heat and energy required Rock and hydrological cycles: involved in transfer and storing of chemical elements Rates of transfer of important chemical elements are only approximate Carbon, Nitrogen, Phosphorus

1.4 Fundamental Concepts for Understanding Natural Processes as Hazards Science helps us predict hazards. Knowing hazard risks can help people make decisions. Linkages exist between natural hazards. Humans can turn disastrous events into catastrophes. Consequences of hazards can be minimized.

1. Science Helps Us Predict Hazards: Science and Natural Hazards Science is body of knowledge that has resulted from investigations and experiments Scientific Method Formulation of a question Hypothesis is a possible answer to a question and is testable Data is taken to test the hypothesis Scientific investigation has improved understanding of natural disasters

1. Science Helps Us Predict Hazards: Hazards Are Natural Processes They are a result of natural forces Become hazardous when people live or work near the process and land-use changes amplify their effects It is possible to control some of these processes to some degree Most are NOT within our control Best approach to reduction is to identify the processes and delineate the geographic areas

1. Science Helps Us Predict Hazards: Forecast, Prediction, and Warning of Hazardous Events Uniformitarianism “The present is the key to the past” Human interaction has an effect on geologic processes “The present is the key to the future” Environmental Unity One action causes others in a chain of actions and events

1. Science Helps Us Predict Hazards: Forecast, Prediction, and Warning of Hazardous Events, cont. Specific date, time, and magnitude of event Forecast Range of probability for event Some hazards can be predicted; most can be forecasted

1. Science Helps Us Predict Hazards: Forecast, Prediction, and Warning of Hazardous Events, cont. Identify the location of probable event Most hazardous areas can be mapped Example: volcanoes and earthquake events are located Determine probability of event Estimated based on past events and current conditions

1. Science Helps Us Predict Hazards: Forecast, Prediction, and Warning, cont. Observe precursor events Events that precede a hazardous event Example: earthquakes often precede volcanic eruptions Forecast or predict event Forecast gives certainty of event Prediction will give an estimated time for events Warning the public Involves statements to media and public at large

Hazard Prediction or Warning

2. Knowing Hazards Risks Can Help People Make Decisions Risk = (probability of event) x (consequences) Consequences: damages to people, property, economics, etc. Acceptable Risk is the amount of risk that an individual or society is willing to take Frequent problem is a lack of reliable data for either the probability or consequences

3. Linkages Exist Between Natural Hazards Hazards are linked to each other Some events may cause others Example: Hurricanes and flooding Hazards linked to earth materials Example: Some rock types are prone to landslides

4. Humans Can Turn Disastrous Events into Catastrophes: Examples of Disasters in Densely Populated Areas Increases number of people at risk More loss of life compared to hazardous event in a less dense area Examples Mexico City: 10,000 killed in 1985 8.0 earthquake Izmit, Turkey: more than 17,000 killed from 1999 earthquakes

4. Humans Can Turn Disastrous Events into Catastrophes: Population Growth as a Factor in Hazards World’s population has more than tripled in the past 70 years Population grows exponentially Increases exposure to hazards, increased pollution, reduced availability of food and clean drinking water, and a greater need for waste disposal and energy resources

The Twentieth-Century Rapid Rise in Human Population

4. Humans Can Turn Disastrous Events into Catastrophes: Magnitude and Frequency of Hazardous Events Impact of hazards depend on Magnitude: Amount of energy released Frequency: Interval between occurrences Other factors: climate, geology, vegetation, population, and land use Magnitude-frequency concept Frequency of an event inversely related to magnitude Land use affects magnitude and frequency of events

5. Consequences of Hazards Can Be Minimized Primarily reactive in dealing with hazards Search and rescue Firefighting Providing emergency food, water, and shelter Need to increase efforts to anticipate disasters and their effects Land-use planning limitations Hazard-resistant construction Hazard modification or control Total losses are direct losses and losses related to human actions

5. Consequences of Hazards Can Be Minimized: Reactive Response Effects from a disaster can be Direct (felt by fewer individuals): people killed or dislocated, buildings damaged, etc. Indirect (affect many more people): emotional distress, donation of money or goods, taxes for recovery, etc. Recovery from disaster Emergency work Restoration of services and communication lines Reconstruction

Recovery from Disaster

5. Consequences of Hazards Can Be Minimized: Anticipatory Response Options for avoiding and minimizing effects of disasters depends on Perception of hazards Attitudes of people to be affected Awareness Anticipatory options include Land-use planning Insurance Evacuation Disaster preparedness Artificial control

1.5 Many Hazards Provide a Natural Service Function There are some benefits to hazards Examples: Flooding provides nutrients for soil Landslides form dams to create lakes Volcanoes create new land

1.6 Global Climate Change and Hazards Global climate change is likely to change the incidence of some natural hazards Sea-level rise increases coastal erosion Deserts and semiarid regions are likely to expand Warmer ocean water is likely to increase storm activity

Chapter 1 Summary Hazards involve repetitive events. Geological conditions and materials largely govern the type, location, and intensity of natural processes. Subcycles of the geological cycle are the tectonic cycle, rock cycle, hydrological cycle, and various biogeochemical cycles.

Chapter 1 Summary, cont. Five fundamental concepts establish a philosophical framework for studying natural hazards: Science helps us predict hazards. Risk analysis is an important component in our understanding of the effects of hazardous processes. Linkages exist between different natural hazards as well as between hazards and the physical environment. Hazardous events that previously produced disasters are now producing catastrophes. Consequences of hazards can be minimized.

Chapter 1 Summary, cont. Environmental unity states that one action often leads to others in a sequence. Human population growth and poor land-use decisions are turning former disasters into catastrophes. The magnitude-frequency concept states that the larger the magnitude of a natural process, the less frequently it occurs.

Chapter 1 Summary, cont. Consequences of a natural hazard event can produce loss of life and property. Natural service functions refer to benefits provided by a particular process. Global climate change will likely affect the frequency and intensity of natural hazards.