Physical Geography of India

India has a fragile network of over 1,382 islands. However, several of these islands are under natural and anthropogenic threat. In fact, one such island, the bio-diverse and uninhabited Parali I in the Lakshadweep archipelago, has entirely disappeared from the map.

Reasons behind the phenomenon of sinking/shrinking islands in India’s coastal regions:

• Sea level rise: With climate change and global warming, sea levels are rising, thus, leading to submergence of low-lying islands.
• Natural erosion: Natural erosion due to high-intensity waves, tidal currents, and storms lead to the erosion of shorelines and cause the islands to shrink.
• Human activities: Human activities can disrupt natural ecosystems like coral reefs and mangrove forests that provide shoreline protection, leading to the shrinking of islands.
  • Deforestation and land use change accelerate soil erosion exacerbating the shrinking of islands.
  • Dam construction reduces the sediment proportion in the river depositing silt near these islands leading to shrinkage.
• Extreme weather events and disaster: Increased frequency of unseasonal cyclones in recent times increasing coastal erosion and subsidence due to earthquake and tsunami also sinks islands.

Implications for the nation:

• Economy: Shrinking or sinking islands can lead to the loss of land and natural resources, such as agricultural land, freshwater sources, and fishing grounds due to salt water incursion.
• Further, the tourism potential declines. For example, the island of Pamban in Tamil Nadu, a popular tourist destination, has seen a decline in tourism due to the loss of beaches and other natural attractions.
• Also, as islands shrink, the cost of maintaining infrastructure such as roads, buildings, and ports can increase significantly owing to constant adaptation as per the changing landscape.
• Environment: Shrinking islands can lead to environmental degradation, including soil erosion, loss of biodiversity, and increased pollution as it affects species endemic to the region.
• Strategic: Certain island groups such as Andaman & Nicobar, Lakshadweep etc. are situated at a strategic location, subsidence of which would have implications for the country in terms of security, trade etc.

Implications for island communities:

• Displacement of people: The shrinking of islands can lead to the displacement of people resulting in social and economic upheaval as they rely mainly on fishing and agriculture.
• Increased vulnerability to natural disasters: As islands become smaller, they become more vulnerable to natural disasters and communities become more vulnerable to increased food, water, and health insecurity.
• Loss of cultural heritage: Island communities often have a rich cultural heritage that is tied to their land and environment. E.g. Sagar Island known for the Gangasagar festival has supposedly been lost to sea at least four times.
• Loss of livelihood: The inhabited Divar Island in Goa is threatened by damage to the ancient protective bunds. As a result, there has been an influx of saline water that has impacted agriculture and drinking water in the island.
• Poor quality of life: The need to constantly rebuild their homes; where crops are routinely submerged by saline water affects the quality of lives due to associated uncertainties.

In this context, measures such as large scale mangroves plantation, adopting green technologies, early warning systems, etc. can go a long way in replicating the story of hope from Tamil Nadu: the Vaan island in the Gulf of Mannar, which was brought back to life.