In News:

India’s coastline has grown significantly over the past five decades, now extending 11,098 km in 2023-24, compared to 7,516 km in 1970. This marks an increase of 47.6% in just over five decades, attributed to a more precise methodology for measuring coastlines.

Key Factors Behind the Growth:

New Methodology for Measuring Coastlines:

• The old methodology used straight-line distances to measure the coastline, a method that didn't capture the complexity of India’s coastlines.
• The updated approach incorporates bays, estuaries, inlets, and other geomorphological features, offering a more accurate and detailed representation of the coastline.
• Advanced technologies like geospatial mapping have been used to ensure greater precision.

State-wise Recalculated Coastline Changes:

• Gujarat:
  • Old coastline (1970): 1,214 km
  • New coastline (2023-24): 2,340 km
  • Growth: The largest absolute increase in coastline, nearly doubling its size.
• West Bengal:
  • Old coastline: 157 km
  • New coastline: 721 km
  • Growth: A dramatic 357% increase, marking the highest percentage rise.
• Tamil Nadu:
  • Old coastline: 906 km
  • New coastline: 1,068 km
  • Growth: Revised length now exceeds Andhra Pradesh’s coastline, which was 1,053 km.
• Puducherry:
  • Old coastline: No major shift, but the updated data shows a contraction of 4.9 km (-10.4%), due to erosion and recalculations.
• Kerala:
  • Old coastline: Relatively small increase of 30 km (5%), the smallest among the states.

Notable Observations:

• Andhra Pradesh is developing new ports like Ramayapatnam, Krishnapatnam, and Kakinada Gateway, aiming to boost economic growth and employment by leveraging its expanding coastline.
• The recalculated coastline helps in better maritime planning, focusing on port development, tourism, biodiversity conservation, and coastal erosion.

Impact of Coastline Expansion:

• Economic Growth:
  • Coastal states, particularly Gujarat and West Bengal, benefit from an expanded coastline that improves maritime trade, port infrastructure, and tourism.
  • The expansion supports industrialization, with growing logistics and transportation activities along the coast.
• Environmental Considerations:
  • The new data aids biodiversity conservation, helping to track coastal erosion and accretion (land buildup), especially in areas like the West Coast.
  • Understanding these changes is essential for disaster preparedness and sustainable coastal management.
• Coastlines of Emergence and Submergence:
  • Emerging Coastlines: Land rising due to uplift or falling sea levels, such as along the Tamil Nadu Coast.
  • Submerged Coastlines: Land that has sunk or been submerged due to rising sea levels, particularly noticeable along parts of Kerala’s coast.

Geographical Significance of the Expanded Coastline:

• India’s coast touches three major bodies of water: the Bay of Bengal (east), the Indian Ocean (south), and the Arabian Sea (west).
• The expansion reflects more than just geography—accurate coastline data is crucial for policy planning, maritime security, and resource management.