Anti-tsunami measures create storm
On the third anniversary of the Asian tsunami, scientists are questioning the viability and effectiveness of protective measures that India has taken after the Dec 26, 2004 disaster.india Updated: Dec 26, 2007 15:12 IST
On the third anniversary of the Asian tsunami, scientists are questioning the viability and effectiveness of protective measures that India has taken after the Dec 26, 2004 disaster.
Steps taken by India to avoid large-scale destruction in the event of another tsunami have triggered an environmental controversy that is likely to figure in a special session at the Indian Science Congress beginning Jan 3 at Vishakapatnam.
To keep the waves at bay, long stretches of India's southeastern coastline known as the Coramandel coast have been walled permanently. Simultaneously, several rows of casuarina trees have been planted on the sandy beaches under the shelterbelt project that began July 2005. Using $6 million funding from the World Bank, a total of 4,700 hectares of the shelterbelt and 1,400 hectares of mangroves are being created.
"When finished, the shelter belt will stretch from Kanyakumari to Chennai - more than 1,000 km," Rakesh Vashist, additional principal chief conservator of forests of Tamil Nadu, told IANS.
But the large scale sea walling and conversion of sand dunes into a forest of exotic and water-guzzling casuarinas have angered ecologists and environmentalists.
"Sea walls are useless in areas with shallow shelves as in Nagapattinam, which suffered the worst in 2004," said Ravi Bhalla, fellow at the Foundation for Ecological Research, Advocacy and Learning (Feral) in Pondicherry.
"On the other hand, they limit access to the beach, cause competition for parking boats and drying fish nets, and can actually worsen the problem of coastal erosion in adjacent areas," he added.
Bhalla pointed out that Pondicherry lost its beach after a seven-kilometre wall was built in 2002 to protect its harbour, and 80 per cent of the coast of Kerala was eroded after sea walls were erected to protect homes a few years ago.
"The construction of sea walls can also seriously impact the natural process of sand dune formations which form natural barriers and wind breakers," he said.
Vallam Sunder, professor of ocean engineering at the Indian Institute of Technology (IIT) in Chennai who is advising the Tamil Nadu government on coastal protection, admits he is disappointed with the way sea walling is going on.
"I gave them (the government) only a conceptual design but they began implementing it," Sunder told IANS over telephone.
"They are simply dumping big boulders and calling it a sea wall. It is not correct. I have raised objection. I hope they have stopped it," he said.
One only has to visit Kotakuppam near Pondicherry to realize that what is actually being passed off for a sea wall is nothing but an ugly pile of giant boulders.
Critics say sea-walling work is progressing at top speed not because its proponents understand the science of it but because it creates jobs and provides a windfall for quarry owners - some of who are politicians - who supply the boulders.
Similarly, they say that the hype of the shelterbelt provided a very good justification to convert huge areas of common land, consisting of sand dunes, to forest department controlled plantations.
Kartik Shanker, assistant professor of ecology at the Indian Institute of Science (IIS) here, told IANS: "Actually, large scale casuarina plantation along the coast is destroying coastal features such as sand dunes which may be critical to coastal integrity and are themselves excellent coastal defence against natural disasters."
C.K. Sreedaran, Tamil Nadu's principal chief conservator of forests, denies that the shelterbelt was a mistake.
"The apprehension that it would destroy the coastal ecology has no basis. And there is no question of any rethinking (on this project)," Sreedaran told IANS over telephone from Chennai.
Forest officials say the shelterbelt project has scientific basis and was prompted by reports by the M.S. Swaminathan Research Foundation (MSSRF) in Chennai that said areas shielded by mangroves suffered less damage in the 2004 tsunami.
But Bhalla and Shanker said this conclusion has since been intensely debated by scientists in India and elsewhere.
Some have argued that the reduced damage has more to do with features such as the elevation of the site from sea level and distance from the sea than with mangrove plantations.
Others, including Bhalla, claim that lesser damage to homes behind the mangroves during the 2004 tsunami "is not at all surprising because there is enough literature to show that mangroves only grow in calm waters already within sheltered coastal areas".
Bhalla's study that questions the scientific basis for shelterbelt was published in the Sep 25 issue of the Current Science journal published by the Indian Academy of Sciences in Bangalore. Scientists of MSSRF who originally sold the shelterbelt idea to the government did not reply to repeated requests for comments on the study.
But Kandasamy Kathiresan, a professor of marine biology at the Parangipettai Centre of Annamalai University, believes no harm will be done.
"Sand dunes are mostly unstable structures which are strengthened and stabilized by dune vegetations including casuarinas," Kathiresan said in an email interview.
"The casuarinas are well known wind breakers, protecting the natural sand dune systems against storm surges," he said.
Ecologists at Bhalla's organisation, Feral and the Bangalore-based Ashoka Trust for Research in Ecology and the Environment (Atree), plan to continue their dialogue with the Tamil Nadu government over the wisdom of turning the beaches of the Coramandel coast into casuarina forests.
Bhalla said: "The important issue here is that somehow the protective role of vegetation against the tsunami was blown up by the local media and policy makers immediately embarked on a bio-shield project. The protective role of dunes was totally forgotten in the process."