1

GEOG 3402: Natural Hazards

INTRODUCTION

• Natural Hazards: the interaction of human exposure and vulnerability and natural extremes that creates loss and disruption in social and environmental systems. (We include Smith’s “super hazards” like asteroids, in this category).

• Technological Hazards: accidents of technologies (e.g., transport) that cause loss and disruption in social and environmental systems.

• Context Hazards: Environmental change and degradation that worsens other hazards (e.g., climate change, sea level rise)

• Disasters: hazard events inculcating large loss of life and severe property / economic loss.

GEOG 3402: Natural Hazards

INTRODUCTION

• Disasters: hazard events causing large loss of life and severe property / economic loss. (Chap. 2) We’ll deal mostly with natural disasters. [Smith and Petley: actualization of a hazard].

• “Risks” colloquially just another word for

hazards and disasters

• Risk: a measure of likelihood of an event and its consequence (Chap. 4)

More Hazards Concepts

• Risk: the probability of a given event AND the potential loss from that event (likelihood times consequence).

• This allows for a situation where: – high probability / low consequence

– low probability / high consequence

• BUT: Complex relationships among;

– intensity

– frequency (probability)

– risk

same risk!

Hurricane Katrina -

2005

1800 deaths, $100b+ damages

Kobe, Japan Earthquake, 1995 at estimates of deaths at 5,000 and losses at $200bmost costly and most deadly recently in a developed country.

2

Dec 26, 2004 Indian Ocean Tsunami

Up to 230,000 fatalities;

hundreds of millions in

poorly-measured damages.

The waves up to 30 m (100 ft)

The earthquake was originally recorded as 9.0 (Richter scale), but has been upgraded to between 9.1 and 9.3. At this magnitude, it is the second largest earthquake ever recorded on a seismograph. This earthquake was also reported to be the longest duration of faulting ever observed, lasting between 500 and 600 seconds. It was large enough that it caused the entire planet to vibrate at least half an inch, or over a centimetre.[2] It also triggered earthquakes in other locations as far away as Alaska

Haiti death toll: Government says toll could be

massive, but firm numbers elusive The Haiti earthquake destroyed thousands of homes and the Haitian

government is warning that "hundreds of thousands" could be dead. But

death tolls are frequently inaccurate in the immediate aftermath of such

disasters. (CSM, 2009)

Global disaster losses (similar to Fig. 2.6 in text, both from Munich RE).

A simple, environment and society “interaction” model for

hazards (and resources) from Burton, Kates and White

reading.

Natural EventsSystem

Human useSystem

Hurricane

Flood

Earthquake

Tsunami

wildfire

Agriculture

Settlement

Transportation

Housing

Environmental Hazard Impacts Response

Protection (Prevention): modify the event:

(Dams, levees, cloud seeding, etc.)

Magnitude, frequency, duration, extent

Adaptation: modify human

vulnerability (land use

regulations, preparedness,

etc.)

economic loss

Mitigation: Modify the Loss

Burden (Disaster aid,

insurance)

Exposure / Vulnerability

Prevention and

protection

systems

Levees, sea walls,

even cloud

seeding

3

Disaster aid, relief,

insurancePrediction, warning

and evacuation,

sheltering systems

Example: “Alquist-Priolo” zone in Calif: new building is restricted near

faults.

Land Use

mitigation

Global disaster losses (similar to Fig. 2.6 in text, both from Munich RE).