3.4.2 Impacts of and responses to Storm Hazards

Question 1

What are the forms that storm hazards can take?

Answer 1

• High winds - wind speeds on the ground can reach more than 300 km/h. Wind can destroy buildings, uproot trees, and carry debris (e.g. cars and trees) long distances before smashing them into other objects.
• Storm surges - a storm surge is a large rise in sea level caused by high winds pushing water towards the coast, and by the low pressure of a storm.
• Heavy rain - as warm, moist air rises it cools and condenses, causing torrential rain. E.g. in 1966, over 1000 mm of rain fell in 12 hours at La Réunion (an island in the Indian Ocean) during Tropical Storm Denise.
• Flooding - heavy downpours can cause river discharge to increase suddenly, causing rivers to overtop their banks and flood the surrounding area. Heavy rain and storm surges can also cause flooding in coastal areas.
• Landslides - water infiltrates soil and rock, making it less stable and increasing the risk of landslides.

Question 2

What are storm surges?

Answer 2

A large rise in sea level caused by high winds pushing water towards the coast, and by the low pressure of a storm.

Question 3

Social impacts of storm hazards

Answer 3

• People may drown, or be injured or killed by debris that’s blown around or carried in flood water.
• Houses are destroyed, so people are left homeless.
• Electricity cables are damaged and supplies are cut off.
• Flooding causes sewage overflows, contaminating water.
• The lack of clean water can help diseases spread.
• Damage to agricultural land can cause food shortages.

Question 4

Economic impacts of storm hazards

Answer 4

• Buildings and infrastructure cost a huge amount to rebuild.
• Businesses are damaged or destroyed, so they can’t trade.
• Agricultural land is damaged affecting commercial farming.

Question 5

Environmental impacts of storm hazards

Answer 5

• Beaches are eroded and coastal habitats (e.g. coral reefs) are damaged. Sediment deposited in aquatic ecosystems may damage fish breeding grounds.
• Environments are polluted, e.g. by salt water, oil and chemicals spilled from damaged factories.
• Landslides can block watercourses, so they change course.

Question 6

Political impacts of storm hazards

Answer 6

• People may blame the authorities for shortages of food, water and energy, leading to conflict and political unrest.
• Expensive repairs to buildings, infrastructure etc. limit the amount of moeny that can be spent on development.

Question 7

Prevention of storm hazards

Answer 7

Storms cannot be prevented, but they can be studied to help scientists understand which areas are most likely to be affected. This means that future developments can be planned to avoid high-risk areas.

Question 8

Preparation for storm hazards

Answer 8

People and authorities can make sure they are prepared for a storm, e.g. emergency services can train and prepare for disasters, governments can plan evacuation routes to get people away from storms quickly and educate people about how to prepare for a storm (e.g. stockpiling water and food and boarding up windows).

Question 9

Adaptation for storm hazards

Answer 9

Buildings can be designed to withstand tropical storms, e.g. by using reinforced concrete or by fixing roofs securely so they’re not blown off. Buildings can also be put on stilts so they’re safe from floodwater. Flood defences can be built along rivers (e.g. levees) and coasts (e.g. sea walls).

Question 10

Global warming and tropical storms

Answer 10

• Global warning has been linked to increased tropical storms.
• Rising sea level means higher storm surges, even from relatively minor storms, which increases coastal flooding and storm damage along the coast.
• Recent scientific evidence shows a link between the intensity of the tropical storms and higher ocean temperatures, particularly driven by global warming.
• Tropical storms become weaker when they travel over land or colder ocean water. Global warming is causing global ocean temperatures to increase, reducing the effectiveness of this natural barrier.

Question 11

How has the intensity of tropical storms changed?

Answer 11

• Studies have shown that the intensity of tropical storms has increased by around 70% in the Atlantic and Pacific Oceans.
• The percentage of hurricanes classified as Category 4 or 5 has increase over the same period. These studies correlate with the rise in sea surface temperatures in regions where tropical cyclones typically originate.