The long stretch of coastline on either side of the Indian peninsula is subjected to varied coastal processes and anthropogenic pressures, which makes the coast vulnerable to erosion. Of the nearly 7,500 km long coastline
DATA: The state-wise analysis suggests that erosion exceeds more than 50 percent in two States, namely, West Bengal (63 percent) and Puducherry (57 percent), followed by Kerala (45 percent) and Tamil Nadu (41 percent). Odisha is the only coastal State, which has more than 50 percent of accretion, followed by Andhra Pradesh with 42 percent
Reasons for erosion
>the Himalayan Rivers, floods are equally significant in causing severe riverbank erosion. States like Assam and West Bengal are exposed to recurrent floods and riverbank erosion. The state of affairs of river erosion can be understood from the dire situation in Sunderbans in West Bengal and Majuli Island in Assam. Climate change and sea-level rise, combined with other morphological reasons, has led to a staggering land erosion of 170 sq. km .
>close to 5,700 km is prone to cyclones and tsunamis, hence prone to erosion due to storm surge, tidal surge, wind, anthropogenic activities and wave actions.
>There are 13 coastal States/ UTs (West Bengal, Odisha, Andhra Pradesh, Tamil Nadu, Kerala, Karnataka, Maharashtra, Goa, Gujarat, Puducherry, Andaman & Nicobar Islands, Lakshadweep, Dadra Nagar & Haveli, and Daman & Diu are vulnerable to cyclones and therefore affected by coastal erosion
>Similarly, more than 40 million hectares (12 percent of land) out of a geographical area of 3,290 lakh hectares is prone to floods Similarly, more than 40 million hectares (12 percent of land) out of a geographical area of 3,290 lakh hectares is prone to floods
>The loss of habitat and livelihoods due to river and coastal erosion has socioeconomic and environmental impacts. At present, the major interventions have been structural like the construction of spurs, embankments and walls to prevent erosion
>given rapid climate change, the issue of erosion may be exacerbated with the melting of glaciers
>the increase in frequency and intensity of storms in the coastal area may increase coastal erosion
>Both sea level rise and thermal extension of water may shift the high tide lines.
>the natural and man-made causes of river erosion like, storms, extreme waves, sea level rise, persistent low pressure due to climate change, development of ports, damming of rivers, dredging of tidal inlets.
>There are major rivers (Indus, Brahmaputra, Narmada, Tapi, Godavari, Krishna and Mahanadi) along with their numerous tributaries that make up the river system of India.
>The rivers bring heavy sediment load from the catchments. These, coupled with an inadequate carrying capacity of the rivers are responsible for causing floods, drainage congestion and erosion of river-banks. The States affected by river erosion are in the northwest region, central region, Deccan region and Brahmaputra region with the highest river erosion happening in Ganga and Brahmaputra river basins. Similarly, the worst affected States by sea erosion are West Bengal, Puducherry, Odisha, Kerala, Gujarat, Karnataka, Maharashtra, Goa, Tamil Nadu, Andhra Pradesh and Daman & Diu
River Erosion' – Issues and Challenges'.
erosion and deposition are natural processes of the river. Dynamics of flow and sediment transport are the principal elements responsible for morphological changes.Understanding this nature of river will help in planning, designing and maintaining of flood protection/ river drainage work and water resource projects
>morphological studies help in finding the vulnerable spots for bank erosion, deposition, river bed aggradation and river bed degradation.
>preventive measures for river bank erosion, including structural and nonstructural measures. Structural measures include reservoirs, diversion structures, channel improvement, construction of spurs, groynes, porcupines, gabions, construction of bank revetment along with launching apron, vetivers, geosynthetics and non-structural measures include flood plain zoning.
Solutions:
>Jal Jeevan Hariyali project for last one year. Under this programme, the State Government gives emphasis on afforestation, construction of soil and water conservation structure, checking of dams etc
>The structural interventions may include by-passes of constructions eg. ports, embankments, dikes/polders, groynes, revetments, breakwaters, closure dams, cross dams, land reclamation, sand nourishments, dune restoration, mangrove conservation, restoration, hybrid solutions, setback lines, zoning, managed realignment and protected areas
>Non-structural measures for disaster management through preparedness and mitigation measures include early warning system, evacuation plans, infrastructure improvement, cyclone shelters, refuge areas, flood proofing (houses, infrastructure), CBDRM and awareness-raising, emergency response, relief & recovery programs, insurance and livelihood improvement programmes.
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