17 October: coastal erosion
Saturday 17 October 2026
GS Paper 3 · 250 words · 15 marks
Explain the causes and effects of coastal erosion in India. What are the available coastal management techniques for combating the hazard?
(UPSC Mains 2022, GS Paper 3, Q18)
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How to approach this question
What the question asks.
| Part | What to write |
|---|---|
| Explain the causes | Natural and human, with how each works |
| Effects | On people, livelihoods, land and water |
| Management techniques | Hard and soft measures, and planning rules |
A shape that works in 250 words.
- Introduction. The scale, with a source.
- Causes, natural and human, with examples.
- Effects, with one named place.
- Techniques: hard, soft, and planning.
- Conclusion. Which approach to prefer, and why.
What to avoid.
| Mistake | What to do instead |
|---|---|
| Only natural causes | Ports, dams and sand mining matter as much |
| Seawalls as the only answer | Say what seawalls do to the next stretch of coast |
| No Indian place named | Name Puducherry, Odisha or Kerala |
| Ending on "a holistic approach is needed" | Say which measures to prefer |
A model answer
The National Centre for Coastal Research found that about a third of India's mainland coastline eroded between 1990 and 2018. West Bengal was worst affected, with about 60% of its coast eroding. Erosion is natural, and human activity has made it faster.
Causes
- Natural: waves, storm surges from cyclones, and sea-level rise.
- Ports and breakwaters block the sand that currents carry along the coast. The beach north of Puducherry's harbour shrank after it was built.
- Dams trap river sediment, so deltas such as the Mahanadi's get less sand.
- Sand mining and loss of mangroves remove natural buffers.
Effects
- Homes and villages are lost. Satabhaya in Odisha's Kendrapara district was largely swallowed by the sea, and its families were moved inland.
- Fishing communities lose beaches to land boats.
- Salt water enters groundwater and farmland.
- Roads and other coastal infrastructure are damaged.
Management techniques
- Hard: seawalls, groynes and breakwaters. They protect one stretch and often move erosion further along.
- Soft: beach nourishment, dune restoration and mangrove planting. Puducherry used an artificial reef and nourishment to rebuild a beach.
- Planning: the CRZ Notification, 2019, limits building near the shore. Shoreline mapping shows which stretches are at risk.
Conclusion
India should prefer soft measures and plan by sediment cell, the stretch of coast that shares one supply of sand. Hard structures should be a last resort, with checks on their effect further along the coast.
Word count: 231.
Why this answer works. It answers all three parts under their own headings. It explains how ports and dams cause erosion. It names a place for causes, effects and techniques. The conclusion picks an approach.
Where it could be stronger. The planning point could say what the CRZ Notification, 2019, allows and forbids near the shore.