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Typhoon Malakas
Status: Closed
| Type of posting | Posting date(EST): | Summary | Downloads |
|---|---|---|---|
| Final Posting | 9/26/2016 10:30:00 AM |
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Final Posting | Summary
Posting Date: September 26, 2016, 10:30:00 AM
With sustained winds estimated at 185 km/h (115 mph), Typhoon Malakas made landfall on Kyushu Island, Japan, early in the morning local time on September 20, 2016, and proceeded on a drenching track over southern, central, and eastern portions of the country. Heavy storm-induced precipitation resulted in widespread flooding, with damage to buildings, vehicles, and roadways, as well as crops.
Reported Damage and Impacts
Typhoon Malakas made landfall on Kyushu Island with wind speed equivalent to a Category 3 hurricane, but the soaking rain from the storm—which began in Japan hours before landfall—caused the greater impact. Storm surge was not a significant risk in this event.
According to the Japan Meteorological Agency (JMA), 110 millimeters (4.33 inches) of rain per hour was reported in Takanabe in Miyazaki Prefecture on Kyushu on September 19, while more than 578 millimeters (22 inches) were recorded in Nobeoka, also in Myazaki Prefecture, during a 24-hour period ending the morning of September 20.
Many homes suffered flood damage, and in some areas floodwaters caused houses to collapse. Many vehicles also were impacted, and a number of drivers had to be rescued from submerged cars. On Kyushu Island, more than 114,000 households were reported to have lost power when wind and rain felled utility poles.
Disruptions from Malakas were widespread. Government officials advised approximately 600,000 people living in six prefectures in western Japan to leave their homes. Hundreds of flights were cancelled, rail transportation was curtailed in some areas, and highway travel became hazardous due to washed-out roads, primarily in the south and southwest.
The sixth named storm to make landfall on Japan in the 2016 season, Malakas weakened quickly after moving overland and soon was downgraded to a tropical storm. Reportedly one person was killed by the storm and another few dozen were injured.
Exposure at Risk
Japan has strict and well-enforced construction codes, although many existing structures predate the existence of these codes. Residential exposures in Japan are dominated by wood construction; non-wood residences primarily consist of steel and concrete. Modern wood construction typically demonstrates the best performance in typhoons among all wood constructions in Japan. However, damage to roof coverings and windows can allow wind-driven rain to enter and cause extensive damage to contents. Furthermore, dislodged external components can become wind-borne debris and cause damage to surrounding structures and glazing.
Larger multi-family apartment buildings and commercial and industrial structures are generally engineered and made of reinforced concrete or steel. Complete structural collapse of engineered buildings due to typhoons is extremely rare; damage is usually confined to nonstructural components, such as mechanical equipment, roofing, cladding, and windows.
A significant portion of Japan’s industrial stock is of non-engineered light metal construction, which is one of the construction types most vulnerable to high winds. Low-rise, non-engineered commercial and industrial buildings usually perform similarly to single-family homes under typhoon conditions.
Even with modern flood-control structures, the risk of flood damage remains high in Japan. For a given flood depth/effective surge depth, a residential wood frame building generally will sustain more damage than a residential masonry building. Concrete construction is less vulnerable to flood than steel or masonry. Commercial and apartment buildings usually have stronger foundations than residential buildings, and are thus better able to resist flood loads. Water damage to machinery and contents drives most flood-related loss; also, because damage is usually limited to the lower stories of a building, high-rise buildings will experience a lower damage ratio than low-rise buildings because a smaller proportion of the building is affected.
Insurance Impact
Typhoons are the most frequent cause of property loss in Japan from catastrophes. Although winds are the predominant driver of loss, the country regularly experiences “wet” storms like Malakas with extreme precipitation-induced flooding that contribute substantially to damage. Wind damage typically is automatically covered under standard fire insurance policies, but flood damage is not. The density of insured exposures is relatively low in Kyushu.