Claims that coastal tree barriers can halt the might of a tsunami are false and dangerous, says a team of international marine scientists.
There are many reasons for preserving the world’s dwindling stocks of mangroves but protecting people from tsunamis is not one of them, they added.
Four year on from the devastating 2004 Boxing Day Tsunami, which killed more than 250,000 people, the team of scientists issued a strong warning against coastal communities and governments putting their trust in mangrove and tree barriers.
“Following the Boxing Day tsunami, scientific studies were released which claimed that the damage to coastal communities had been less in places where there was a barrier of trees or coastal vegetation,” explained Dr Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
“As a result, there has been a lot of tree planting in coastal areas affected by the tsunami in the hope it will protect coastal communities in future from such events,” he observed.
“However these studies looked only at the presence or absence of vegetation and the extent of damage – and did not take account of other important variables, like the distance of a village from the shore, the height of the village above sea level or the shape of the seabed in concentrating the tsunami’s power.”
The study by Dr Baird’s team concluded that there was, as yet, no evidence that coastal tree belts could provide meaningful protection against a tsunami or even storm surges produced by cyclones, such as the surge that followed Cyclone Nargis in Burma earlier this year, which killed more than 150,000 people.
As a result it would be extremely dangerous to rely on tree planting alone to shield coastal communities in the event of future tsunami or storm surges, they warned.
The findings will be published shortly in a report by the United Nations Environment Programme.
Source: Australian Research Council press release