Green roofs and typhoons
The 2012 typhoon season was a big one but none of the storms caused any real damage to our green roofs.
People are always asking about green roofs and typhoons and quite rightly so. The typhoon season is a fact of life in this part of the world, so much so that in Taiwan there are constantly-updated “typhoon-watch” screens attached to the checkouts of all convenience stores.
Typically the season runs from May to October and 2012’s season, in Hong Kong and across the region, was as busy as any in recent history. In 2012, Hong Kong saw the T8 signal raised three times: for Typhoon Doksuri in June; for Vicente in July; and Kai-tak in August.
A Typhoon No.8 signal is raised when Hong Kong is expected to register winds between 63-117 km/h, and as anyone who has lived in Hong Kong knows and knows well, the T8 means the shutting down of public transport and the closing of schools and businesses.
People are well used to typhoons here and they batten down the hatches and look forward to the lovely clear and breezy weather that always follows. Sometimes the storm doesn’t live up to the predicted expectation or it suddenly veers the other way and the population gets a surprise day off and the dim sum restaurants get packed.
Typhoon Vicente was the exact opposite. It intensified rapidly into a Severe Typhoon as it approached Hong Kong over the South China Sea and in the late evening it reached a peak intensity of 155 km/h before making a dawn landfall close to Macau on the other side of the Pearl River Estuary.
It was the first time the T10 signal was raised in Hong Kong since 1999 and damage across the city was widespread but it was nothing compared to neighboring Guangdong Province, where more than 44,000 hectares of farmland were inundated and more than 1,000 houses collapsed. In the Philippines, Hong Kong, Macau, China, Vietnam, Laos, Burma, Vicente caused damage of more than US$60 million.
While all of us at GreenRoof Asia are absolutely respectful of the power of typhoons, we are also very proud to say that none of the storms that swept through Hong Kong caused any real damage to our green roofs. Yes there was peripheral damage – some shrubs got bashed about and some vegetables got ripped out – but it was minor, especially compared to the widespread landscaping damage seem across Hong Kong after Vicente.
It would seem likely that climate change is going to bring more severe weather and while green roofs can offer real solutions to help mitigate against some of this – especially against the heat island effect and urban flooding – they also have to stand the most severe tests of weather.
This year’s typhoon season was a very good test… and all our green roof systems stayed completely intact.