Tropical Cyclone Case Study: Typhoon Haiyan 2013

Typhoon Haiyan (known locally as Yolanda) struck the Philippines on 8 November 2013 and remains one of the most powerful tropical cyclones ever recorded at landfall. This case study is essential for the Edexcel B specification as an example of a tropical cyclone affecting a lower-income country (LIC) or newly emerging economy (NEE). Haiyan demonstrates how vulnerability, poverty and geography can combine to produce catastrophic impacts even when warning systems are in place.

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Background: The Philippines

The Philippines is an archipelago (group of islands) in the western Pacific Ocean, consisting of over 7,000 islands. It lies directly in the path of tropical cyclones forming in the world's most active basin — the western North Pacific. On average, the Philippines is struck by 20 tropical cyclones per year, of which approximately 8–9 make landfall.

Key Facts About the Philippines (2013)
Population	~98 million
GDP per capita	~$2,800 (lower-middle income)
Main livelihoods	Agriculture, fishing, services
Poverty rate	~25% of population below poverty line
Geography	Low-lying coastal areas, mountainous interiors, dense coastal populations
Warning system	PAGASA (Philippine weather service) issues warnings, but communication in remote areas is limited

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Formation and Track

Typhoon Haiyan formed over the western Pacific Ocean on 2 November 2013, beginning as a tropical disturbance near Micronesia. It rapidly intensified over the warm waters of the Pacific, where sea surface temperatures exceeded 29°C — well above the 27°C threshold required for cyclone formation.

Key meteorological data:

Characteristic	Data
Peak sustained winds	315 km/h (195 mph) — the highest ever recorded at landfall at the time
Saffir-Simpson equivalent	Category 5 (the maximum rating)
Central pressure	895 hPa (one of the lowest ever recorded)
Storm diameter	~600 km
Landfall	Guiuan, Eastern Samar, 8 November 2013
Storm surge	Up to 7.5 metres in Tacloban, Leyte

Exam Tip: Haiyan's peak sustained winds of 315 km/h at landfall were the highest reliably recorded for any tropical cyclone making landfall at the time. This statistic makes it an excellent example for demonstrating the extreme power of tropical cyclones.

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Primary Effects

The primary effects of Typhoon Haiyan were devastating:

Wind Damage

• Winds of up to 315 km/h flattened entire communities. In the city of Tacloban (population ~220,000), approximately 90% of buildings were damaged or destroyed.
• Concrete buildings lost roofs and walls; wooden and corrugated iron housing was completely demolished.
• Power lines and telecommunications infrastructure were destroyed across the affected region.
• Coconut plantations — a major source of income — were devastated, with an estimated 33 million coconut trees destroyed.

Storm Surge

• The storm surge was the deadliest aspect of Haiyan. In Tacloban, a surge of up to 7.5 metres swept through the city.
• Many residents were unfamiliar with the term "storm surge" — warnings used this English technical term rather than describing it as a giant wall of seawater. Many did not understand the danger and failed to move to higher ground.
• The surge carried ships, vehicles and debris inland, crushing buildings and drowning thousands.
• Entire coastal communities on the island of Leyte were swept away within minutes.

Rainfall and Flooding

• Haiyan produced heavy rainfall of up to 400 mm in some areas over 24 hours.
• Combined with the storm surge, this caused widespread flooding in low-lying areas.

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Secondary Effects