L2 - Environmental Disasters and Risks

Question 1

Disasters result from [……..] between human and physical systems

Answer 1

Complex Interactions

Question 2

State two scales with which disaster impact can be assessed

Answer 2

• Direct-Indirect

- Losses-Gains

Question 3

Which continents are disasters most costly? What are the principal hazard types?

Answer 3

• Americas (Storms)

- Asia (Earthquakes & Flooding)

Question 4

State 4 trends in disasters

Answer 4

• Since 1920: # people killed steadily declining
• Since 1950s: # people affected increasing
• Since 1950s: # disasters reported increasing
• Since 1970: $ of damage has been increasing

Question 5

Name a conceptual framework for evaluating events

Answer 5

Magnitude and Frequency

Question 6

Give an example of a high mag, low freq event

Answer 6

Ice Age Megafloods

Question 7

Give an example of a low mag, high freq event

Answer 7

Wind ripples on sand dunes

Question 8

How do calculate the frequency of events of a particular magnitude?

Answer 8

Recurrence Interval (return period)
- Represented by a T

Question 9

How do you calculate a recurrence interval

Answer 9

T = (n+1)/m

• n: # of years on record
• m: rank of event magnitude

Question 10

Define Recurrence Intervals

Answer 10

Average time separating events of a similar magnitude

Question 11

Give an example of a recurrence interval

Answer 11

Great Storm - 1987
- Most severe windstorm since 1703
- 200 year return period
£1.4 billion in damages

Question 12

What do histograms of return periods tend to show

Answer 12

• Positive skew - high freq, low mag events more common

Question 13

Problems with recurrence internal?

Answer 13

Climate change -> increased variability = increased incidence of extreme events

Question 14

Name a risk assessment metric

Answer 14

Disaster Risk Index (DRI)