New Delhi: Almost one-third of India’s 6,632km coastline was lost to soil erosion between 1990 and 2016, said a National Centre for Coastal Research report.

The report, National Assessment of Shoreline Changes along Indian coast, which mapped the shoreline changes along the Indian coast for the last 26 years, found that the West Bengal coast was the most vulnerable.

The minister for earth sciences, Harsh Vardhan, told Parliament that the eastern coast underwent more erosion due to frequent cyclonic activities from Bay of Bengal in past three decades, compared to the western coast, which remained largely stable. While 33% of the coast was under erosion, only 29% was accreting (growing) and 38% was in stable state, he added.

According to the report, West Bengal (63%) and Puducherry (57%) are most-vulnerable to erosion, followed by Kerala and Tamil Nadu at 45% and 41%, respectively. Odisha on the eastern coast is the only state where the coast witnessed expansion of more than 50%.

“Coastal erosion has become an alarming threat for the population and, if we do not take immediate steps, we would end up losing more land and infrastructure to the sea. The damage will be irreversible. Coastal population will bear the maximum brunt, especially villages and recent habitations, including buildings, hotels and resorts which are at risk," said M.V. Ramana Murthy, director, National Centre for Coastal Research (NCCR), Chennai.

The report instituted by the ministry of earth sciences, said that the Indian mainland has lost about 234.25sq. km of land to the sea from 1990 to 2016. “West Bengal lost maximum land of 99.05sq. km during the period," said R.S. Kankara, senior scientist at NCCR, who prepared the report.

While climate change and rising sea-levels have exacerbated the problem, scientists say dams on river basins have reduced the flow of sediments to the coasts. “Increasing construction activities along the coast involving dredging which tend to throw all sediments into the deep sea have further worsened the situation," said Murthy.

He added that such analysis would help in improving preparedness to face coastal hazards such as storm surges and Tsunamis.

Changing shorelines not only threaten the coastal infrastructure and cause potential loss to the economy, but could also impact the fishing industry.

The analysis involved mapping the 6,632 km long coastline along nine states and two union territories using 26 years of satellite data from 1990 to 2016 by researchers from NCCR, which was followed by field verifications.

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