Context
- A national survey of India’s coastline from 1990 to 2016 shows West Bengal saw the maximum proportion of coastal erosion in India.
Background
- Coastal zones are dynamic interfaces between land and water as a result of which locations of high-density development.
- Coasts are subjected to frequent natural hazards including flooding, storm impacts, coastal erosion and tsunami inundation.
- Coastal erosion is a constant problem with most open-shores of India.
- With, nearly 250 million people living within 50 km of coastline in India, they are threatened by coastal erosion.
- Thus governments at various times have initiated studies on shoreline movement in India.
Highlights of the report
- The National Centre for Coastal research under Ministry of Earth Sciences has carried out a study on shoreline changes along mainland of India between 1990 and 2016.
- As per the report, Indian mainland has lost about 234.25sq. km of land to the sea from 1990 to 2016.
- Out of the 7,517 km long coast line of India:
- 2,533 km, or 38 per cent remained stable
- 2,156 km or 33 per cent had eroded
- 1,941 km expanded
- 11% of Indian coast is susceptible to high levels of erosion of more than 5 m per year.
- According to the survey:
- Natural causes of erosion include wave action, wind action, storms, tidal action and sea level.
- Anthropogenic causes of erosion are construction, mining and dredging of coastal areas.
- East coast witnessed more erosion as a result of frequent cyclonic activities from Bay of Bengal in past three decades, while west coast is relatively more stable.
- West Bengal saw the maximum proportion of eroded coastline with 63 per cent its coastline eroded.
- It is followed by Puducherry (57 per cent), Kerala (45 per cent) and Tamil Nadu (41 per cent).
- Goa and Maharashtra have the most stable coastlines in India.
Significance of the Report
- Coastal erosion leads to irreversible loss of land and infrastructure to the sea.
- Besides changing shorelines will severely impact the fishing industry.
- Thus a national survey of coastline will provide inputs for framing policies to address the stress of the people residing in coastal areas.
- Further it would also help in improving preparedness to face coastal hazards such as storm surges and Tsunamis.
Highest Erosion in West Bengal
- West Bengal has about 158 km of coastline, covering an area of 534 sq km.
- It has one of the largest deltaic regions of the world.
- Besides it is home to tidal halophytic mangroves.
- WB has lost maximum land of 99.05sq.km or 63% due to coastal erosion during 1990-2016 as a result of tides, tropical cyclones and storm surges etc.
- While the land gain due to accretion has been only 16 sq km.
Impact
- Climate change refugees
- The Sunderbans is facing severe erosion on its western and south eastern parts with loss of more than 80 sq km of coastal land.
- With population density of about 1,000 people per sq km, the stress has led to migration from these coastal areas and islands called “climate change migration.”
