Typhoon Mangkhut proves Hong Kong urban jungle is no place for trees
As most of the road blockage was due to fallen trees, one line of argument could be: if these trees had not been there, most of our roads would not have been blocked.
Firstly, the conception that people and trees can live harmoniously together is just an ideal and can never work in populous areas like Hong Kong. This is because trees require large areas to stay healthy. Accordingly, we must make a choice between trees and people/facilities.
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Secondly, it is assumed that, if a tree is healthy, it can remain in place without any stabilising measures. It is obvious that any office working under such a misconception will result in many trees in populous areas. However, these trees are likely to fail under a high wind load.
Consider replacing roadside trees with ‘concrete planters’ of small plants or shrubs
The obvious solution is to adopt an engineering approach of having a larger safety margin. Should this approach be adopted, many of the existing trees would be removed, unless protective measures are provided, and these might be expensive.
People might argue that we cannot resist the power of nature and that it is normal for strong storms to cause damage. But look at the lamp posts in Hong Kong – they could resist the high wind load because they have a strong foundation of concrete block embedded below ground.
Finally, the Tree Management Office should consider replacing roadside trees with “concrete planters” of small plants or shrubs. These will keep our environment green and, at the same time, are safer and cheaper to maintain. The MTR should also consider building strong fencing to protect overhead cables from falling trees or branches.
Dr Wong Hong-yau, Happy Valley
