Coasts: Opportunities and Hazards » Managing Tropical Storms

Why manage tropical storms?

We cannot stop a tropical storm. What we can do is reduce the harm it does to people, homes and money. This is called managing the impacts. A simple way to remember the main approaches is the four Ps.

Key terms:

• Prediction: working out where and when a storm will hit, so people get warning.
• Preparation: getting people ready before a storm arrives.
• Planning: decisions made years ahead about where and how to build.
• Protection: physical structures and natural barriers that reduce damage.

Remember from the last lesson that LICs often lose more lives and HICs often lose more money. The four Ps aim to cut both.

1. Prediction

Prediction does not stop the storm, but it gives time to act. A good warning saves lives, and each warning is low cost for every person it helps.

• Strength: gives people time to leave and prepare. Warning people costs little per person compared with building defences.
• Limitation: storms can change direction or strength at short notice, so forecasts can be wrong. Warnings are useless if people cannot hear them or do not trust them.

2. Preparation

Preparation is about people knowing what to do. It happens in the days and years before a storm.

• Emergency kits: families keep water, food, a torch, a radio, batteries and first aid supplies.
• Drills: schools and communities practise what to do, so people stay calm when it is real.
• Evacuation plans: people know when to leave, where to go and how to get there.

• Strength: low cost, and it helps everyone, including poor families.
• Limitation: it relies on people taking part. Some people cannot leave because they have no transport, or will not leave their homes and belongings. Kits do not protect buildings.

3. Planning

Planning means making rules and decisions long before a storm so that a place is built safely. It is done by governments and councils.

Technique	What it is	How it reduces impacts
Land-use zoning	Rules on what can be built where	Keeps homes and hospitals off the most flood-prone coastal land
Building codes	Laws on how strong buildings must be	New buildings survive high winds, so fewer collapse
Evacuation routes	Marked, well-built roads leading inland	Lets people leave quickly and safely
Cyclone shelters	Strong buildings that people can reach and stay in	Saves the lives of those who cannot leave the area

• Strength: works for the long term and protects whole communities.
• Limitation: slow, and needs money and strong government control. Rules are hard to enforce, and building codes do not help old buildings. People living in housing built without planning may not follow zones because they have nowhere else to go.

4. Protection

Protection is about physical defences that stand between the storm and people. Building codes (planning) are the rules that make sure new buildings are storm-resistant (protection).

• Strength: reduces damage directly. Mangroves are cheap, renew themselves and also support wildlife and fishing.
• Limitation: sea walls and strong buildings are very expensive. Walls can be flooded over the top by a big surge. Mangroves take years to grow and can be cut down for building or shrimp farms.

Why LICs and HICs differ

HICs can afford the expensive options. LICs often cannot, so they rely more on the cheaper ones.

Four Ps	HICs	LICs
Prediction	Advanced satellites and computers, with warnings reaching nearly everyone	Often rely on forecasts from other countries; warnings may not reach remote villages
Preparation	Regular drills and public information campaigns	Often run by charities or local groups, with fewer resources
Planning	Strict building codes, enforced by inspectors	Codes may exist but are hard to enforce, and many homes are built without permission or planning
Protection	Strong buildings, sea walls and other defences	Few can afford sea walls; low-cost options such as mangroves and raised homes are more common

This is one big reason why the same storm often kills fewer people in an HIC. Low-cost methods such as warnings, drills and mangroves give the best value for LICs.

Judging the four Ps

When you evaluate, you weigh up strengths and limitations and then make a judgement. Use these questions:

• How much does it cost, and who pays?
• Does it save lives, money or both?
• Who benefits? Does it reach poor people as well as rich people?
• Is it sustainable? This means it can carry on for the long term without running out of money or harming the environment. Mangroves and drills are very sustainable. Concrete walls need costly repairs.

No single P is enough. The best approach is to combine them: predict the storm, prepare people, plan the area and protect key places.

Common mistakes

Exam-style question

Fig. 1.1 gives made-up information about two coastal countries that are both hit by tropical storms.

Fig. 1.1	Country X	Country Y
Income group	HIC	LIC
People warned before a storm (%)	98	55
Cyclone shelters per 100 000 people	12	1
Coastline with mangroves (%)	5	40

(a) State what is meant by prediction of a tropical storm. [1 mark]

(b) Give two examples of preparation for a tropical storm. [2 marks]

(c) Explain one limitation of building codes as a way of managing tropical storms. [3 marks]

(d) To what extent can Country Y reduce the impacts of tropical storms using the four Ps? Use Fig. 1.1 in your answer. [6 marks]