Coastal erosion is a growing concern for India, as highlighted by recent data shared during the Winter Session of Parliament. This article explores the issue, its causes, impacts, and the steps taken to mitigate it.
Overview Of Coastal Erosion In India
Coastal Geomorphic Features of India
East Coast of India
- Tamil Nadu: Deltas, long narrow beaches, spits, tidal flats, mangroves, coral reefs, sand dunes, Ridge swale complex, etc.
- Andhra Pradesh: Deltas, long narrow beaches, spits, mangroves, cliffs, long sand dunes, Ridge swale complex, etc.
- Odisha: Deltas, long beaches, spits, tidal flats, long sand dunes, ridges, etc.
- West Bengal: Large delta, very thick mangroves, tidal channels, islands, dunes, tidal flats, beaches, etc.
West Coast of India
- Kerala: Estuaries, lagoons, barriers, spits, dunes, tombolo, cliff, beaches, etc.
- Karnataka & Goa: Estuaries, spits, sand dunes, tombolo, cliff, wave cut platforms, beaches, etc.
- Maharashtra: Estuaries, cliffs, small sand dunes, tombolo, cliff, wave cut platforms, pocket beaches, etc.
- Gujarat: Marshy land, tidal flats, estuaries, cliffs, mud flats, mangroves, wave cut platforms, beaches, etc.
Source: National Centre for Coastal Research (NCCR)
33.6% of India’s coastline is eroding, while 26.9% shows accretion (growth), and 39.6% remains stable. In Karnataka’s Dakshina Kannada district, nearly 48.4% of the coastline has eroded over the past three decades, according to a study by the National Centre for Coastal Research (NCCR). The study utilized satellite imagery and field surveys conducted between 1990 and 2018.
To better understand the risks, the Indian National Centre for Ocean Information and Services (INCOIS) developed detailed Multi-Hazard Vulnerability Maps. These maps combine data on water levels, shoreline changes, and sea-level rise to pinpoint vulnerable areas.
The report titled “Shoreline Change Atlas of the Indian Coast” by the National Centre for Coastal Research (NCCR) provides a comprehensive analysis of shoreline dynamics along India’s coastline.
The NCCR conducted a detailed study of India’s 6,632 km-long coastline from 1990 to 2018. The findings revealed that 33.6% (2,318.31 km) of the coastline is undergoing erosion, 26.9% is experiencing accretion, and 39.6% remains stable.
State-Wise Shoreline Erosion Data
- Tamil Nadu: Highest erosion, with 42.1% of its coastline eroded.
- West Bengal: Faces significant erosion due to the Sundarbans delta being highly dynamic.
- Kerala and Gujarat: Display large-scale erosion and accretion due to heavy human interference.
- Andhra Pradesh: More stable but shows vulnerability in river deltas like Krishna and Godavari.
Regional Significance
- Eastern Coast: Higher erosion rates due to tropical cyclones (e.g., Odisha, Andhra Pradesh).
- Western Coast: Greater stability but faces localized issues from industrialization (e.g., Mumbai, Gujarat ports).
Causes of Coastal Erosion
Natural Causes
- Wave Action: Waves transfer energy to the shoreline, causing sediments to move and reshape the coast.
- Winds: Winds not only generate waves but also cause landward movement of sand dunes, leading to erosion.
- Tides: High tides push waves further onto the shore, increasing erosion along the foreshore.
- Nearshore Currents: These currents, driven by winds, tides, and wave actions, transport sediments, altering the shoreline.
- Storms: Storm surges and high-energy waves during storms cause significant coastal damage in a short time.
- Sea Level Rise: Rising sea levels, driven by global warming, exacerbate coastal erosion, leading to land loss.
Human Activities
- Urbanization: Construction in coastal zones disrupts natural sediment flow and weakens the coast’s resilience.
- Dredging and Mining: Activities like sand mining and dredging of channels accelerate erosion.
- Coastal Structures: Harbors, seawalls, and groins alter wave and sediment dynamics, worsening erosion in some areas.
- Deforestation of Mangroves: Removal of natural barriers like mangroves leaves the coast unprotected against waves and storms.
States Most Affected
- Karnataka: Nearly 48.4% of Dakshina Kannada’s coastline has eroded.
- West Bengal: Around 60.5% of the coastline, including the Sundarbans, faces erosion.
- Kerala: Approximately 46.4% of the coastline is eroding, affecting communities and ecosystems.
- Tamil Nadu: Coastal erosion impacts 42.7% of its shoreline, posing risks to infrastructure.
Impacts of Coastal Erosion
- Loss of Land: Coastal erosion reduces usable land for agriculture and settlements.
- Community Displacement: Families living near eroding coasts are forced to relocate, creating socio-economic challenges.
- Infrastructure Damage: Roads, bridges, and buildings are at risk of destruction.
- Biodiversity Decline: Vital habitats like mangroves and wetlands are degraded, affecting marine life.
Government Initiatives To Tackle Coastal Erosion
- Hazard Line Mapping: A hazard line has been established to track shoreline changes and guide disaster management efforts.
- Coastal Regulation Zone (CRZ) Notification, 2019: The CRZ notification aims to protect coastal ecosystems while allowing for controlled development and erosion control measures.
- Flood Management Schemes: These schemes support states in implementing anti-erosion projects with technical and financial assistance.
- Coastal Management Information System (CMIS): This system collects data to plan and design coastal protection measures effectively.
- Restoration Projects: Initiatives in Puducherry and Kerala have demonstrated successful restoration and protection of vulnerable coastal areas.
Innovative Solutions for Coastal Protection
- Artificial Reefs: Structures that reduce wave energy and stabilize the shoreline.
- Eco-Friendly Breakwaters: Sustainable materials are used to protect shores without harming marine ecosystems.
- Geo-Tube Barriers: Installed in areas like Odisha, these barriers provide a buffer against erosion.
- Mangrove Plantations: Mangroves help stabilize coasts and absorb wave energy.
Coastal erosion is a pressing issue that demands both immediate action and long-term strategies. By addressing the root causes and implementing innovative solutions, India can better protect its coastlines, communities, and biodiversity.