CHENNAI: Only 10 per cent of the Tamil Nadu coastline can be considered stable, reports a study conducted by the Indian Space Research Organisation (ISRO) and the Central Water Commission (CWC) of the Ministry of Water Resources.
According to the study, the State’s shoreline is undergoing change and it has increased by about 25.45 km due to accretion. The percentage of accretion of coastline is highest for Tamil Nadu, around 62.3 per cent of the total shoreline when compared to other coastal States.
It is the Indian Ocean tsunami of 2004 that is responsible for this, just as it resulted in a huge coastal erosion in Andaman.
However, more than the accretion, Tamil Nadu should be alarmed about the finding of the study that the State has less than 10 per cent of stable coastline.
R Ramesh, director of Chennai-based National Centre for Sustainable Coastal Management, an autonomous body of the Ministry of Environment and Forest, told Express that the lack of stable coastline is a matter of concern.
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,” Ramesh 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.
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 — have 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.
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 highlights that only 1,580 km of the total 8,414 km of coastline (excluding the mouths of estuary, rivers and creeks) in the country is considered stable coastline.