According to catastrophe modeling firm AIR Worldwide, Typhoon Matmo, the third typhoon in the western Pacific Basin in less than three weeks, “made landfall in Taiwan around midnight, local time, Tuesday night with winds over 160 km/h [100 mph] and torrential rain but Taiwan largely escaped major property damage according to reports so far.”
AIR senior scientist Kevin Hill said: “By Wednesday 4:20 a.m., local time, the storm had weakened and moved back over water. Matmo then made landfall in Fujian Province, China, late Wednesday afternoon, local time. Wind damage in China is expected to be light, but there is a risk of flooding and landslides in hilly and mountainous areas.”
According to AIR, insurance penetration in China generally is low, especially for residential structures. Accordingly, although some damage is expected from wind, flood, and landslides, insured losses are not expected to be significant as a result of this typhoon.
The Central Weather Bureau of Taiwan had placed the entire island under typhoon warning, in addition to the small islands of Ludao and Lanyu to the southeast of the main island. Bands of locally heavy rain, as much as 50 cm [nearly 20 inches] in some locations, triggered flash flooding and landslides.
Some 5,400 residents living in the mountainous areas prone to landslides were evacuated. More than 31,500 homes and businesses lost power.
Late Wednesday, local time, a domestic TransAsia Airways flight crashed near Magong airport on the Penghu islands, which lie between Taiwan and China. Officials have blamed the crash on the storm.
Occasional wind gusts over 80 km/h will continue over parts of Taiwan through at least Thursday morning, local time.
Dr. Hill added: “Matmo, which weakened to a Category 1 typhoon as it moved over Taiwan and across the Formosa Strait, poses a risk of heavy flooding on its projected path west of Wenzhou, Hangzhou, and Shanghai.
“Satellite imagery indicates that Matmo has experienced rapid weakening over the last several hours. It will continue to weaken due to interaction with land and the Wuyi Mountains over eastern China through Thursday, local time, eventually becoming a remnant low by early Friday. Pockets of locally heavy rainfall and wind gusts over 95 km/h [59 mph] are possible in China’s Fujian and Zhejiang provinces. Rainfall of 75-150 mm [2.95 to 5.9 inches] is expected. For the Shanghai metro area, locally heavy rainfall and a few wind gusts over 64 km/h [40 mph] are possible Thursday and Friday.
“An approaching mid-latitude trough from the northwest will absorb Matmo later this week, causing a northeast turn and taking it into the Korean Peninsula where heavy rain and flooding will be major concerns. Heavy rainfall is expected across northern South Korea, including Seoul as well as southern and central North Korea,” he concluded.
According to AIR, residential homes in China where Matmo made landfall consist mostly of masonry construction. Apartment buildings, which have become common in recent years, are made largely of reinforced concrete and confined masonry. Commercial and industrial structures are also largely of reinforced concrete, but older structures are of unreinforced masonry and some confined masonry.
At Matmo’s wind speeds at landfall, only minor damage is expected to the general building stock. For apartment buildings and commercial facilities, expected damage is very low to none. For houses, wind damage can be more considerable. Trees may be blown over if their root structures are sufficiently weakened by the storm’s heavy rains, and they can cause damage to nearby buildings.
Minor to moderate levels of damage to light fabrication facilities and warehouses, especially in the case of older structures, and to signage, also can be expected. Flooding is expected to cause more damage than wind, especially to the poorly constructed houses in the hilly and mountainous countryside, where mudslides and river overflow are substantial dangers.
Source: AIR Worldwide