Posted on 07 Feb 2011
Catastrophe modeling firm AIR Worldwide estimates that insured losses to properties and business income from the Category 5 (Australia Bureau of Meteorology intensity scale) cyclone Yasi that struck Australia will be between AUD 350 million (USD 354 million) and AUD 1.5 billion (USD 1.5 billion).
“In the aftermath of the most powerful cyclone to strike Australia’s east coast since 1918, many residents are expressing relief; while the storm was indeed damaging, its impact on heavily populated areas along the country’s northeast coast was less than expected,” said Dr. Vineet Jain, principal engineer, AIR Worldwide.
According to AIR, throughout Queensland and affected areas, newer commercial buildings sustained only minor structural damage, illustrating the effectiveness of Australia’s building code even in the face of such a major storm. Non-engineered residential structures performed less well, with some sustaining major structural damage, mostly to roofs. The towns of Tully and Cardwell were particularly hard hit, with many buildings sustaining significant structural damage, particularly caravans which are quite vulnerable to high wind-speeds. Meanwhile, flooding is a major concern in
Townsville, Ingham and Giru. Cairns, with a population of over 160,000, was spared major damage, though more than 65 per cent of homes there are without power.
“Losses from Yasi may well exceed those from Cyclone Larry in 2006,” explained Dr. Jain. “Larry, which followed a similar path to Yasi, though it tracked slightly to the north and had less intense winds—caused insured losses of about AUD 540 million (in 2006 AUD), according to the Insurance Council of Australia, which lies within the estimated range posted by AIR in real time in 2006.”
As Yasi made landfall on Wednesday, the storm’s strongest sustained winds were on the order of 137 – 145 km per hour with gusts as high as 185 km per hour observed in and around the Cardwell to Lucinda Point region. This region corresponds to Yasi’s southern eyewall—where the strongest winds occur. Gusts exceeding 119 km per hour extended as far south as Townsville—some 175 km south-southeast of the landfall location—and as far inland as 200 km, to near Hughenden (where wind gusts as high as 112 km per hour were recorded).
“Precipitation was generally less than 150 mm along the coastal areas, with as much as 369 mm of rain recorded in Woolshed, a town at 556 meters elevation in the Great Dividing Range,” continued Dr. Jain. “Storm surge as high as 5 meters was reported in Cardwell with 3 meters of storm surge reported in Clump Point and 2.3 meters of storm surge reported in Townsville. Because the cyclone struck 500-1000 km north of the region worst-hit by flooding last month, as well as the storms relatively fast forward speed, Yasi’s inland flooding effect is expected to be minimal. Still, there is a continued risk of localized flash flooding well inland today, as a much weakened Yasi continues to push to the west-southwest.”
Elsewhere, the town of Innisfail is isolated by flood waters. Below Innisfail, in the town of Tully, residents reported massive destruction, including roofing blown off homes and downed power lines. Below Tully Heads in the town of Cardwell, structural damage to homes was severe; early reports indicated damage to more than 200 homes. Approximately 60 properties suffered major structural damage, including the loss of roofs, while 100 others sustained damage considered moderate. Most of the remainder were reported to have minor damage.
Yasi also caused damage to Queensland’s agriculture; early predictions suggest that 75% of the nation’s banana supply and half the region’s sugarcane have been obliterated by Yasi’s wind