Storm hazards

Question 1

State the conditions needed for a hurricane to develop

Answer 1

• Sea temperatures above 27 degrees
• Ocean depth above 70m
• 5 degrees north or south of the equator

Question 2

Describe the structure of a tropical storm

Answer 2

• Central eye (10-50km) with calm conditions
• Eye wall is the most powerful part; produces heavy rainfall and harsh winds
• Cloud and rain extend in a series of waves, where storms and tornadoes are commonly formed

Question 3

Describe the distribution of tropical storms

Answer 3

• Occur between latitudes 5-20 digress north and south of the equator
• Most destructive; Caribbean Sea, Bay of Bengal, Southeast Africa

Question 4

Explain how the magnitude of tropical storms is measured

Answer 4

Saffir-Simpson Scale

• 5 levels based on pressure, wind speed, storm surge and damage potential
• Scale 5 has: winds above 250km/h and storm surges over 5.5m

Question 5

Describe the frequency of tropical storms

Answer 5

• Average lifespan 7-14 days

- 80-100 tropical storms a year globally

Question 6

Describe storm surges as an impact of tropical storms

Answer 6

• Surge of water up to 3m
• Caused by low atmospheric pressure which allows the sea to rise vertically and powerful winds
• Most deaths of tropical storms are due to storm surges
• Agriculture takes long to recovery as soil is contaminated

Question 7

Describe strong winds as an impact of tropical storms

Answer 7

• Exceed 150km/h
• Buildings collapse, damage to roads, bring down transmission lines, damage agriculture
• Can hurl pieces of debris

Question 8

Describe flooding as an impact of tropical storms

Answer 8

• Warm, humid air from the storm produces large amounts of rainfall
• Can cause landslides and mudslides

Question 9

Name some physical factors influencing the impact of a tropical storm

Answer 9

• intensity of storm
• Speed of movement
• Distance from the sea (storm declines towards land)
• Physical landscape of impact zone

Question 10

Name some human factors influencing the impact of a tropical storm

Answer 10

• Population of impact zone
• Level of preparedness
• Ability to predict
• Nature of buildings

Question 11

Explain prediction as a management strategy

Answer 11

• Prediction depends on the state of monitoring
• Poorer areas do not have sufficient communication systems to provide an efficient evacuation
• Tropical storms follow an erratic path so it’s not always possible to give more than 12-18 hours warning

Question 12

Explain prevention as a management strategy

Answer 12

‘Cloud seeding’

• Cause more precipitation to force the storm to release more water over the sea, hence weakening the system
• Concerns were express and research stopped

Question 13

Explain protection as a management strategy

Answer 13

• People educated on how to strengthen their homes
• Cyclone drills
• Land-use planning can limit building in impact zones

Question 14

Name some primary impacts of tropical storms

Answer 14

Storm surges
Strong winds
Heavy rain causing costal flooding

Question 15

Name some secondary impacts of tropical storms

Answer 15

River flooding

Landslides

Question 16

Name some social impacts of tropical storms

Answer 16

Death
Injury
Disruption

Question 17

Name some environmental impacts of tropical storms

Answer 17

Destruction of costal environments
Pollution (e.g. sewage)
Inundation of saltwater

Question 18

Name some economic impacts of tropical storms

Answer 18

Financial costs to local people and governments

Question 19

Name some political impacts of tropical storms

Answer 19

Command and control issues - whose issue is it?

International aid affairs