T.N. 41% loss of shoreline due to erosion: study

In the last two decades, Tamil Nadu reportedly lost 41% of its coastline due to erosion. In order to protect the coastline, the National Center for Coastal Research prepares a report to identify vulnerable areas and propose solutions adapted to the conditions of the site.

Mamallapuram, near the town, and Bommayarpalayam, near Puducherry, are some of the sites chosen to erect structures to prevent further erosion.

On the basis of a national assessment of shoreline changes and a status report for the 1990-2016 period prepared by the NCCR, the Center and the National Institute of Ocean Technology are currently identifying points. hot erosion and implement short-term strategies for immediate protection.

At the present time, dikes and crests, a collection of blocks arranged perpendicular to the coast, are the main artificial structures set up to protect the coastline.

Problems of human origin

According to the recently published report, the development of ports, the construction of dams in rivers that block the supply of coastal sediments are some of the causes of erosion apart from natural causes such as the rise in the level of the sea and the storms.

Citing the status report, MV Ramanamurthy, director of the NCCR, said that Tamil Nadu's coastline extending over a distance of 991.47 km studied over nearly 407.05 km, erosion has become a problem. Only 23% of the coastline has sand accumulation.

"We are developing a combination of hybrid solutions to help with sand accumulation based on site conditions," he said.

The Center has completed projects in Puducherry and Kadalur Periyakuppam near Puducherry, where beach food by adding sediment and underwater reefs has been implemented to recover the shoreline.

Submerged dikes using geosynthetic tubes 2.5 meters high were another way to stop marine erosion. These would be placed about 150 meters into the sea.

The intensity of the waves should be reduced with this technology.

40 km section at the study

The entire coast along the east coast road, which extends 40 km between Pondicherry and Chennai, will be studied for coastal erosion, he said.

"A width of almost 20 meters from the beach has been restored in Pondicherry in the past year. We will also collaborate with IIT-Madras, which has initiated a study on specific requirements for sand accumulation in coastal areas, "added Ramanamurthy.

The project report, funded by the Ministry of Earth Sciences, is expected to be submitted in about six months and the NCCR would work with the Department of Water Resources to implement the coastal protection projects.