Context:
India’s coastline has notably grown from 7,516 km in 1970 to 11,098 km in 2023-24, due to advancements in measurement techniques.
Old vs. New Measurement Methodology:
| Aspect | Old Methodology (1970) | New Methodology (2023-24) |
| Basis of Measurement | Straight-line distances | Included complex coastal formations |
| Coastal Features Measured | Limited to general shoreline length | Incorporated bays, estuaries, inlets, and other features |
| Technology Used | Basic tools and manual calculations | Advanced geospatial technologies and mapping tools |
| Accuracy | Relatively less precise | More precise representation of dynamic coastline |
| Reported Coastline Length | 7,516 km | 11,098 km |
Coastline Changes by States:
- Gujarat: Increased from 1,214 km (1970) to 2,340 km (2023-24).
- Largest absolute growth in coastline length.
- State with the longest coastline.
- West Bengal: Percentage increase of 357%, from 157 km to 721 km.
- Highest growth in percentage terms.
- Tamil Nadu: Revised length increased to 1,068 km from 906 km.
- Overtook Andhra Pradesh.
Tamil Nadu now ranks above Andhra Pradesh in coastline length, becoming the state with the 2nd longest coastline in India, overtaking Andhra Pradesh.
States/UTs with Minimal or Negative Changes:
- Kerala: Smallest increase, adding only 30 km (5%).
- Puducherry: Coastline shrank by 4.9 km (-10.4%) due to erosion and recalculation.
Coastlines of Emergence and Submergence:
- Coastlines of Emergence: Occur when land is uplifted or when the sea level is lowered.
- Features: Bars, spits, lagoons, salt marshes, beaches, sea cliffs, and arches.
- Examples in India:
- Tamil Nadu Coast (Coromandel Coast)
- Kerala Coast (Malabar Coast)
- Coastlines of Submergence: Created when land is submerged due to subsidence or when the sea level rises.
- Examples in India:
- India’s West Coast: Displays both emergence and submergence.
- Northern Portion: Submerged due to faulting.
- Kerala Coast: An emerging section of the shoreline.
- India’s West Coast: Displays both emergence and submergence.
- Examples in India:
Coastal States and UTs of India:
- States: Gujarat, Tamil Nadu, Andhra Pradesh, Maharashtra, Kerala, Odisha, Karnataka, Goa, West Bengal
- Union Territories: Andaman & Nicobar Islands, Lakshadweep, Puducherry, Daman & Diu
Source: TOI
Previous Year Question
Which one of the following pairs of States of India indicates the easternmost and westernmost State?
[UPSC Civil Services Exam – 2015 Prelims]
(a) Assam and Rajasthan
(b) Arunachal Pradesh and Rajasthan
(c) Assam and Gujarat
(d) Arunachal Pradesh and Gujarat
Answer: (d)
Explanation:
India is a large country situated entirely in the Northern hemisphere, with its main land extending between 8°4’N and 37°6’N latitudes and 68°7’E and 97°25’E longitudes.
Arunachal Pradesh, located at 97°25’E longitude, is the easternmost state of India, while Gujarat, situated at 68°7’E longitude, is the westernmost state of India. Therefore, option (d) is the correct answer.