While India’s recent revision of the length of its coastline offers a bounty in development prospects, it also triggers worries in terms of security and ecological concerns. The latest survey by the National Hydrographic Organisation and Survey of India has found the length to be 3,582.21 km longer than that recorded in 1970, bringing the total to 11,098.81 km. A recent gazette notification has formally recognised the revision.
This major correction by almost half is being attributed to a variation in the scale and method of calculation. The 1970 data was computed using manual methods at a scale of 1:45,00,000 or smaller, while the new survey measured at a scale of 1:2,50,000 and used modern geographical information software and satellite imagery. The larger scale has captured more intricate details of the bays, inlets, islands and islets, which has helped iron out miscalculations from the 1970 data. The revised length was finalised in August 2023 at the National Security Council secretariat in New Delhi and unanimously accepted by stakeholders across central and state ministries like those for home affairs, external affairs, environment and climate change, earth sciences, and water resources, apart from the surveyors, Indian Coast Guard and National Remote Sensing Centre.
The deviation has mainly come from more accurate details about islands and islets—both onshore and offshore—and estuaries, besides shoreline curves and ragged outlines that were unaccounted for in the older survey. Some islands abutting the coastline that were considered offshore have been re-categorised as inshore ones as they get connected to the mainland during low tide, besides those connected by rail and road bridges. The new survey recorded 1,298 offshore islands and islets and 91 inshore ones—a total of 1,389.
The revised length has major implications for coastal road construction and other infrastructure development. It can boost coastal tourism, be beneficial to fisheries, and help better monitoring of sea erosion and coastal security. The more accurate data calls for the Centre and the states to appropriately enhance coastal security to prevent a 26/11-like attack where the terrorists arrived by the sea route. At the same time, it presents benefits for India’s substantial coastal economy—something that the governments need to optimally translate into new enterprises and jobs.