lecture 1 - Myweb @ CW Post

More documents

Recommendations

Info

Developed countries overall experience much higher monetary losses and low human losses. Developing countries have high casualties and more modest monetary losses due to less development. Definitions Hazard (H) refers to the possibility of a dangerous event. Hazard can be expressed as a statistical probability of a given magnitude event occurring in a specific area within a specified length of time. Vulnerability (V): the level of loss expected from an extreme event (of a given magnitude). It can be quantified from 0 (no loss) to 1 (total loss). Specific Risk (Rs): the probability of a loss. Quantitatively, is is the product of Hazard and Vulnerability (Rs = H x V). Net Impact: the difference between disaster losses and the benefits of using the hazardous area. Medical Consequences Mortality: number of deaths Morbidity: number of injured Traumas: numbers of burns, contusions, fractures, lesions, etc. morbidity > mortality in earthquakes and hurricanes mortality > morbidity in landslides, floods, volcanic eruptions Types of Disasters geophysical origin: earthquakes, tsunamis, volcanic eruptions, landslides, etc. climatic origin: hurricanes tornadoes, severe thunderstorms, floods, drought, fire, etc. biological origin: epidemics, parasite invasions, etc. human origin: warfare, terrorism, urban fires, building collapse, etc. Recurrence Intervals Low or moderate magnitude events generally occur frequently while large magnitude, or extreme events generally occur rarely. The Disaster Cycle Impact - Response - Recovery - Mitigation - Preparation - Next Impact
Energy Sources of Natural Disasters (see the extensive notes in the <strong>lecture</strong> slides online) The sources of energy for natural disasters are: - internal heat that drives geophysical processes like the motions of plates, earthquakes, and volcanoes - solar radiation which drives the water cycle, weather and storms - gravity which causes landslides and tidal processes - impacts by extraterrestrial bodies Origin of the Earth - Origin of Earth’s Primordial Heat solar nebula hypothesis heat in early Earth derived from - gravitational compression - impacts - radioactive decay (greater than today) differentiation of Earth’s core, mantle, crust, hydrosphere, and atmosphere Earth’s Internal Heat Engine - interior is hot today because of primordial heat and continuing radioactive decay - mantle convection Energy from Outside the Earth - solar energy accounts for 99.98% of the energy at the Earth’s surface - the water cycle is driven by solar radiation - the rock cycle is driven partly by internal heat, partly by solar radiation (and gravity) Constructive and Destructive Forces - internal energy drives mountain building, volcanoes, etc. which build up the land - solar energy drives the water cycle responsible for weathering and erosion of land Energy Sources of Extreme Events - energy accumulates gradually over time - when energy is suddenly released, extreme events occur - the human built environment is designed mainly for the gradual flux of energy but may be damaged or destroyed by sudden energy release (extreme events) Internal Heat Energy - earthquakes - tsunami - volcanoes Solar Radiation - severe weather - tornadoes - tropical cyclones (hurricanes, typhoons, cyclones) - floods - drought, fires
Page 1: (lecture on 9/8/08) Introduction: H

lecture 1 - Myweb @ CW Post

Create successful ePaper yourself

Delete template?

Save as template?