Typhoon showed need for Hong Kong to have thorough contingency plans

PUBLISHED : Sunday, 03 September, 2017, 9:01am
UPDATED : Sunday, 03 September, 2017, 10:52pm

The devastation in Hong Kong and Macau caused by Typhoon Hato should serve as a wake-up call to both governments and the private sector about how poorly prepared our cities are to deal with extreme weather conditions.

While the volume of rain from Hato was not excessive, flooding occurred in many parts of both cities because the maximum storm surge occurred at about the same time as the high tide. Unfortunately, few people heeded the Hong Kong Observatory’s warnings that the water level would be at least one metre above the normal tide level.

Flooding can not only cost lives and cause property damage, it can also have other severe consequences, as was demonstrated by Hato. A loss of electricity, which can occur if overhead power lines are blown down by strong winds, can have a knock-on effect, such as the interruption of water supplies and underground train services. Hospitals, stock markets and other businesses may also be affected. There can be long-term economic losses and social disruption.

Thanks to global warming, sea levels will continue to rise. According to an Intergovernmental Panel on Climate Change report, it is likely they could increase by half a metre to one metre by the end of the century. Imagine if this rise was superimposed on the same storm surge and high tide that occurred during Hato. Had Hong Kong had a direct hit from Hato, the storm surge could have been even higher. Also, had Hato brought more rain, the flooding near shores (and in other parts of the city) would have been even worse, with possible landslides as well as flash flooding from rivers.

So how climate resilient are we? As a city, can we have preventive/adaptation measures to reduce the damage brought about by these types of extreme weather?

Detailed preventive measures must be designed and implemented to respond to the potential damage brought about by these extreme events, such as installing flood barriers. There must be comprehensive contingency plans so that, for example, interrupted electricity and water supplies are restored as soon as possible, flood water is pumped from affected areas and storm drains are cleared.

Adequate climate resilience can only happen through the concerted efforts of the government and the private sector. Hopefully, Hato can be a wake-up call for everyone to act.

Johnny Chan, chair professor of atmospheric science, School of Energy and Environment, City University of Hong Kong