IIT study: Sea erosion may shrink islands, submerge islets in Lakshadweep

A major eco threat goes unnoticed in Lakshadweep islands even as the administration is hell bent on passing controversial legislations to make it a major tourism hotspot.

A recent study conducted by scientists at IIT-Kharagpur has found that sea levels around the archipelago may rise between 0.4mm and 0.9mm per year and trigger coastal erosion in many of the islands. This phenomenon may lead to the submersion of smaller islets, the study conducted by the Department of Science and Technology at IIT said.

The study has been published in the journal ‘Regional Studies in Marine Science’.

Lakshadweep consists of 36 islands which include coral and reef formations, spread over an area of 32 sq km in the Arabian sea. Of the 36, while one island has been completely submerged, only 10 are habitable. The maximum elevation in the islands range between four to six metres above Mean Sea Level and minimum elevations is lower than a metre.

The study was conducted considering the 10 islands, which have been studied by IIT scientists from the Department of Architecture and Regional Planning and Department of Ocean Engineering Naval Architecture.

The study says the effect of sea-level rise will range from island to island – some will be affected more than others. The study took help of different climate change models and considered different greenhouse gas scenarios.

The study predicts the islands to face a major coastal erosion by 2030.

“Lakshadweep islands are already facing the impact of sea level rising which is taking place even now. But while many countries have coastal protection measures in place, and even India does have some coastal protection measures, these are not sufficient… By 2030, we expect the islands to face major coastal erosion which will affect the residents of the Union Territory,” Indian Express quoted Prasad K Bhaskaran from the Department of Ocean Engineering and Naval Architecture and one of  the lead authors of the study as saying.

Bhaskaran said it is high time for the government to take coastal protection measures.

“There are two kinds that the government can adopt – soft measures, that is, the creation of mangroves, which we think is more effective. And hard engineering solutions including the building of seas walls- a proposition which is extremely expensive,” he said.

Often used in coastal risk reduction, mangroves slash the speed of wind and waves from the sea hitting the mainland during cyclones and storm, and are excellent soil binders. Sea walls are tall, sturdy and defensive structures built along the coast to protect human habitation from tides, waves and tsunamis.

The study predicts a major sea erosion and resultant land loss in the islands of Chetlat and Amini – while their projection mapping showed that 60-70 per cent of the existing shoreline would see land loss in Amini, Chetlal would experience a shrinkage of 70-80 per cent. The study says the island of Minicoy and capital Kavaratti may also face 60 per cent land loss along the shoreline, while the Union territory’s airport at Agatti island, faces the danger of being damage due to inundation.

“The land use pattern in the islands is such that most of the residential areas occur along the periphery of the islands and cultivation in the centre, increasing the vulnerability of the islands to rising sea levels and erosion. Fisheries, agriculture and tourism are the three main economic sectors of the islanders, all of which are also vulnerable,” the study said.

Of late, the archipelago has been in news over its administrator Praful Patel’s plan to enact a line of Bills which in turn have been rejected by the locals. One of the proposed legislations, the Lakshadweep Development Authority Regulation, 2021 proposes to vest all the planning powers with the administration where the latter can take over any land in the island for “development” purposes. While this has enraged locals, Patel in his defence has said that provisions under the legislation would help the administration develop the islands into a lucrative tourism hotspot.