Chennai: Tamil Nadu’s coastal land mass may have increased by 25.45km but the state has less to cheer about and more to be concerned as only 10 per cent of the entire state’s coast is a stable one.
The shoreline of Tamil Nadu coast is undergoing change and it has increased by about 25.45 km due to accretion, according to a study conducted by Indian Space Research Organisation and Central Water Commission of Ministry of Water Resources.
The study states that the percentage of accretion coastline is highest for Tamil Nadu which is around 62.3 per cent of the total shoreline when compared to other coastal states. The study states that the cause of high accretion is due to the Indian Ocean tsunami of 2004.
Due to it, the Andaman Coast suffered huge erosion, while there was accretion along the Tamil Nadu coast, the study stated. Interestingly, the state should be more alarmed about the increased landmass across the coastline as the study also points out that the state has less than 10 per cent of stable coastline.
R Ramesh, director of Chennai-based National Center for Sustainable Coastal Management, an autonomous body of Ministry of Environment and Forest, told Express that the lack of stable coastline is a matter of concern.
He said there is need to prepare a strategy to strike a right balance before coming up with structures along the coast. “The hydrodynamics need to be studied besides we have to analyse which all projects is compatible along the coast,” he said.
He said the gaining of land mass due to accretion need to be studied. “We have to find out which parts of the coast, the accretion is happening and which part erosion is happening,” he said. Interestingly, the satellite data for detection of violation of land use along the Coastal Regulation Zone and Impact of Port Structures on Shoreline changes by Indian National Centre for Ocean Information Services (INCOIS) and Ministry of Earth Sciences which has been submitted to Union Ministry of Environment and Forest states the three ports--- Chennai Port, Ennore and Katpuli has affected the shoreline.
While the North Chennai shoreline recessed by about 1,000 metres in the last 125 years, the south Chennai gained more land mass. Ramesh agrees with it. He says that this is due to the construction of breakwaters in Ennore and Katpulli, which has arrested the movement of longshore sediment transport resulting accretion in south Chennai and erosion in north Chennai.
Interestingly, the study by Space Applications Centre of ISRO and CWC also highlights that the state along with Puducherry has lost 281.56 km due to erosion. The study is also quite alarming as only 1,580km of the total 8,41 km of coastline (excluding the mouths of estuary, rivers and creeks) is a stable coastline.The study states that the Indian coast has lost a landmass of 73 square km during the period from 1989-91 to 2004-06 timeframe.