Typhoon Haima

Post Landfall 1 | Summary
Posting Date: October 20, 2016, 9:00:00 AM

Typhoon Haima has moved into the South China Sea after making landfall in the Philippines in northeastern Luzon at 11 p.m. local time (15:00 UTC) on Wednesday, October 19, 2016. The system has since weakened significantly; current maximum sustained winds are 149 km/h (~93 mph) down from 212 km/h (132 mph) at landfall, and the current minimum central pressure is 965 mb up from 915 mb at landfall—according to analyses from the Japanese Meteorological Agency (JMA). While the Philippines are dealing with the impacts of the Category 4-equivelant landfall, southeastern China and Hong Kong are preparing for Haima’s second landfall as a weaker Category 1-equivalent storm on October 21, 2016, local time.

Track map of Typhoon Haima as of 15:00 UTC on October 20, 2016. (Source: JMA)

Nowhere else in the world are typhoons more frequent than in the Northwest Pacific basin due to its large expanse of very warm water, which fuels storm formation. Because of Hong Kong's small size, landfalls are relatively rare, occurring every two or three years; however, storms pass close enough to cause loss annually. No typhoon had tracked within 12 km of Hong Kong since Typhoon Usagi in 2013 until Typhoon Nida made landfall 32 km northeast of Hong Kong on August 2, 2016; Typhoon Haima may be the second to break this record in less than a year.

Reported Impact

Widespread flooding, power outages, landslides, and building damage have been reported across four provinces in the northern Philippines. Residents have told media outlets of roofs being torn off, houses being destroyed and ripped from foundations, and school buildings being crushed under falling trees. Firsthand reports of crops have also been recorded, including the flattening of corn and rice plants. Fatalities in the Philippines were kept low (seven have been reported) due to evacuations of approximately 100,000 people in villages prone to landslides ahead of landfall, according to media reports. 

Forecast Track and Intensity

Typhoon Haima is forecast to continue moving west-northwestward across the South China Sea over the next 24 hours, weakening slightly before it makes its second landfall near Hong Kong on October 21, 2016, local time as a Category 1-equivalent storm. A turn northeastward is anticipated after landfall, bringing Haima across the coastal region of southeastern China before dissipating over the weekend.

Exposure at Risk

In coastal regions of southeastern China, houses are typically of confined masonry or reinforced concrete construction with clay tile roofs, which should perform reasonably well in the face of Category 1-equivalent winds.

In contrast, urban apartment buildings tend to be mid- or high-rise structures of confined masonry and reinforced concrete construction, respectively, many of which have commercial establishments on the ground floor. Such better-engineered apartment buildings are common and tend to fare well in Category 1-equivalent winds, although minor nonstructural damage—especially to roofs and wall claddings—is possible.

Commercial and industrial structures still vary widely across China, ranging from poorly constructed low-rise masonry structures to well-maintained mid- and high-rise reinforced concrete buildings constructed to strict code standards. Generally, commercial and industrial buildings are more resistant to wind and water damage than residential buildings.

With high population density along the southeast coast of China, many homes and businesses are at risk. As is often the case with China typhoons, flooding is a major concern; with much of the population located near waterways and along the coast, many homes and businesses are at risk.

Hong Kong is currently home to more than 7 million people. When compared to other coastal areas in the South China Sea, Hong Kong’s mountainous coastline and strongly enforced building codes lessen wind vulnerability. Its heavy investment in a flood defense system keeps inland flood risk within the city relatively low, although flooding is common in the surrounding areas and particularly in the mountainous regions. The reclamation of land is increasing storm surge vulnerability in the region due to exposure proximity to sea level and the narrowing of Victoria Harbour.

Most of the single-family houses in Hong Kong are made of reinforced masonry or concrete. Condominiums, commercial, and industrial buildings—often mid- or high-rise structures—are mainly of reinforced concrete or steel construction, reducing wind vulnerability. However, many high-rise buildings have basements where service equipment is located; such equipment is expensive and vulnerable to water.

Industry Impacts

Residential take-up rates in China are low, while commercial take-up rates vary by province. Insurance take-up rates in Hong Kong are high for both residential and commercial buildings, whereas take-up rates for building contents are higher for commercial and lower for residential lines. Weak-wind typhoons that impact vast areas and generate significant rainfall have often contributed more to insured typhoon losses in China than landfalling storms with high winds.

Post Landfall 1 | Downloads
Posting Date: October 20, 2016, 9:00:00 AM