Chapter 16

Natural Disasters and Catastrophes

Hazards, Disasters, and Catastrophes

• The Most Devastating Natural Hazards

-Earthquake

-Volcanic Eruption

-Landslides

-Hurricane

-Heatwave

-Tsunami

-Wildfire

-Tornado

-Flood

-Drought

Hazards, Disasters, and Catastrophes

• Natural Hazards– Any natural process that is a potential threat to human life and

property

• Disasters– A hazardous event that occurs over a limited time span in a

defined geographic area where the loss of human life and property is significant.

• Catastrophes– A massive disaster requiring significant time and money for

recovery.

Disasters and Catastrophes: Taking a Historic Point of View

• Natural Hazards are Repetitive Events

• Study History to reduce hazards

• Link prehistoric record with historic record and modern measurements to gain insights.

Fundamental Concepts• Natural processes have service functions.• Hazards are predictable• Hazards are producing more catastrophes than

they were before.• Risk from hazards can be estimated• Adverse effects of hazards can be minimized

Natural Processes Have Natural Service Functions

• Physical processes create a varied landscape.

• Periodic disturbance such as earthquake, volcanic eruption, and flooding create:– Fertile soil– Available water– Diverse land and life– Aesthetic beauty

Lava Delta at E. Lae Apunki

Hazards Are Predictable

• Monitor areas where hazards have occurred in the past.

• Statistics can evaluate frequency of a particular event.

• Predict based on geography of where hazards are most likely to occur. Ex. Earthquakes most like near coastlines.

• Forecast events and issue warnings. Ex. Tsunami warning system in the Pacific Ocean.

Tsunami Warning System

Linkages Exist Between Hazards and the Environment

• Often one hazard can create another. Ex. Volcanic eruption can cause a landslide.

• Natural hazards are linked to earth materials. Ex. Weak soils can lead to landslides.

• Hazards can cause the disruption of ecosystems.

Volcanic eruptions can cause mudslides

Hazards are Producing More Catastrophes

• Key Factor: Human Population Growth– Humans pushed into more hazardous areas– 15 cities of over 10 million most vulnerable

• Land use transformation– How we use land effects hazardous events– Ex. Flooding of Yangtze River

Risk From Hazards can be Estimated

• Risk: product of the probability of an event times the consequences

• Acceptable Risk: Risks that individuals or society are willing to take.

Adverse Effects of Hazards can be Minimized

• Active vs. Reactive Response:– Need to be more active– Land use planning– Hazard-resistant construction– Protection of ecosystems– Evacuation plans

• Major Disasters are increasing due to population pressure and poor land-use planning.

• Anticipating hazards

will minimize

suffering and

economic losses

What Does the Future Hold?