Model Answer
0 min readIntroduction
Coastal erosion, defined as the loss of sediment along a coastline, is a significant environmental hazard impacting India’s extensive 7,516.6 km coastline. Increasing frequency and intensity of cyclones, sea-level rise due to climate change, and anthropogenic activities are exacerbating this problem. Recent reports indicate that approximately 57% of India’s coastline is eroding, posing a threat to coastal communities, infrastructure, and ecosystems. The vulnerability is particularly acute in states like West Bengal, Kerala, Tamil Nadu, and Andhra Pradesh, necessitating urgent and comprehensive coastal management strategies.
Causes of Coastal Erosion in India
Coastal erosion in India is driven by a complex interplay of natural and anthropogenic factors.
- Natural Causes:
- Sea Level Rise: Global warming and thermal expansion contribute to rising sea levels, increasing erosion rates.
- Wave Action: Strong waves, particularly during monsoon seasons and cyclones, erode coastlines.
- Tides: Tidal currents contribute to sediment transport and erosion.
- Storm Surges: Cyclones and storms generate storm surges that inundate and erode coastal areas.
- Geological Factors: The geological composition of the coastline (e.g., soft sedimentary rocks) influences its susceptibility to erosion.
- Anthropogenic Causes:
- Construction of Dams and Reservoirs: Reduced sediment supply to the coast due to dam construction upstream. (e.g., Dams on the Cauvery river impacting Tamil Nadu coast)
- Coastal Development: Construction of ports, harbors, and other infrastructure disrupts natural sediment transport.
- Deforestation of Mangroves: Mangroves act as natural buffers against erosion; their removal increases vulnerability.
- Sand Mining: Illegal sand mining depletes sediment reserves and accelerates erosion.
- Urbanization: Increased runoff from urban areas carries pollutants and contributes to erosion.
Effects of Coastal Erosion in India
Coastal erosion has far-reaching consequences across ecological, economic, and social spheres.
- Ecological Effects:
- Loss of biodiversity in coastal ecosystems like mangroves, coral reefs, and salt marshes.
- Habitat destruction for marine and terrestrial species.
- Increased salinity intrusion into freshwater sources.
- Economic Effects:
- Damage to infrastructure (roads, buildings, ports).
- Loss of agricultural land due to saltwater intrusion.
- Decline in fisheries and tourism revenue.
- Increased costs for coastal protection measures.
- Social Effects:
- Displacement of coastal communities.
- Loss of livelihoods.
- Increased vulnerability to natural disasters.
- Social unrest and conflicts over resources.
Coastal Management Techniques
Combating coastal erosion requires a combination of ‘hard’ and ‘soft’ engineering approaches.
- Hard Engineering Techniques: These involve constructing physical structures to protect the coastline.
- Seawalls: Concrete or stone walls built parallel to the coastline. (e.g., Marina Beach, Chennai)
- Groynes: Structures built perpendicular to the coastline to trap sediment.
- Breakwaters: Offshore structures that reduce wave energy.
- Revetments: Sloping structures built to absorb wave energy.
- Soft Engineering Techniques: These focus on working with natural processes to stabilize the coastline.
- Beach Nourishment: Adding sand to eroded beaches.
- Mangrove Restoration: Planting mangroves to act as natural buffers.
- Dune Stabilization: Planting vegetation to stabilize sand dunes.
- Managed Retreat: Relocating communities away from eroding coastlines.
Integrated Coastal Zone Management (ICZM): A holistic approach that considers all aspects of the coastal environment and involves stakeholders in decision-making is crucial for sustainable coastal management. The National Coastal Zone Management Authority (NCZMA) under the Environment (Protection) Act, 1986, plays a key role in implementing ICZM.
Conclusion
Coastal erosion is a pressing issue in India, driven by both natural and human-induced factors. Its effects are multifaceted, impacting ecosystems, economies, and communities. While hard engineering solutions offer immediate protection, a long-term, sustainable approach necessitates integrating soft engineering techniques and adopting a comprehensive ICZM framework. Prioritizing mangrove restoration, regulating coastal development, and addressing climate change are vital steps towards mitigating the hazard and ensuring the resilience of India’s coastal regions.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.