Coastal erosion

11.12.2023

Coastal erosion , Daily Current Affairs , RACE IAS : Best IAS Coaching in Lucknow 

Why in the news?

Recently, the Union Minister informed that according to the study of National Coastal Research Centre, more than one-third of India's coastline is vulnerable to erosion.

Important points:

• Between 1990 and 2018, about 32% of India's coastline suffered sea erosion and 27% of it extended.
• The coastlines of Goa and Maharashtra are among the most stable in the country.

About the National Coastal Research Center study:

• National Center for Coastal Research (NCCR), Ministry of Earth Sciences, has monitored shoreline changes for the entire Indian coastline using multi-spectral satellite images along with field-survey data for the period 1990-2018.
• The NCCR found that 33.6% of the Indian coastline was vulnerable to erosion, 26.9% was subject to accretion and 39.6% was in a stable state.
• 21 out of 31 surveyed beaches in Maharashtra, 13 out of 22 surveyed beaches in Kerala, nine out of 21 surveyed beaches in Tamil Nadu and 13 out of 18 surveyed beaches in Karnataka are facing erosion. Are.
• Under the Coastline Mapping System launched by NCCR, the entire Indian mainland coast with 69 district maps and 9 State and 2 Union Territory (UT) maps at 1:25000 scale to identify areas vulnerable to coastal erosion. 526 maps were prepared for.

About coastal erosion:

• Coastal erosion is the loss or displacement of land, that is, the long-term removal of sediment and rocks along a coastline due to waves, currents, tides, wind-driven water, waterborne ice or other effects of storms.
• Landward retreat of the shoreline can be measured and described on the temporal scale of tides, weather, and other short-term cyclical processes.
• Coastal erosion can be caused by hydraulic action, abrasion, wind and water impact and erosion, and other natural or unnatural forces.

Types of coastal erosion:

hydraulic action:

• This type of erosion is more effective in areas where there are many cracks or joints in the rock, such as limestone or chalk.
• It can also form features such as blowholes, geysers and sea caves.

Friction:

• This is also known as corrosion or sandpapering. It can create smooth and polished surfaces on rock, such as wave-cut platforms.
• It can also erode softer rocks faster than harder rocks, causing differential erosion2.

Attrition:

•  This type reduces the size and shape of rock fragments brought in by waves.
•  It can also increase the efficiency of abrasion, as smaller and rounder particles can act as more effective tools for erosion.

dissolution:

• This is also known as corrosion. It depends on the chemical composition of the rock and water.
• Some rocks, such as limestone and chalk, are more soluble than others, such as granite and basalt.
• It can create features such as karst landscapes, sinkholes and stalactites.

What are the factors causing coastal erosion:

Natural causes:

• Wave energy is considered the primary cause of coastal erosion.
  • Natural hazards such as cyclones, thermal expansion of sea water, storms, tsunamis due to melting of continental glaciers and ice sheets as a result of climate change accelerate erosion.

Coastal Drift:

• Flow of coastal sand can also be considered as one of the major causes of coastal erosion.
• Coastal flow means the natural movement of sediment along the shore of a sea or lake by waves generated by prevailing winds.

Anthropogenic causes:

• Sand mining and coral mining have contributed to coastal erosion which has seen a decrease in sediment.
• Fishing ports and dams built in the catchment areas of rivers and ports reduce the flow of sediment from river mouths, leading to coastal erosion.
• construction of unplanned structure

Effects of coastal erosion:

Loss of biodiversity:

• Coastal erosion affects coastal ecosystems including mangroves, coral reefs and dune systems.

Economic impact:

• It can cause damage to coastal infrastructure, including roads, buildings and ports.

Loss of land:

• This could have serious impacts on coastal communities, infrastructure and ecosystems. Valuable agricultural land, residential areas and tourist destinations may be negatively affected.

Climate refugees:

• Erosion can force communities to relocate as their homes and livelihoods are at risk.

Coastal flooding:

•  As erosion removes natural barriers, such as sand dunes and vegetation, coastal areas become more vulnerable to flooding during storms and high tides.

Loss of revenue:

• This may affect beach tourism and may also affect the local economy due to reduced land productivity.

Major initiatives taken by India for coastal management:

Drawing of danger line:

• The Ministry of Environment, Forest and Climate Change has drawn danger lines for the entire coast of the country. The danger line is an indication of coastline changes, including sea level rise, due to climate change. The line is to be used as a tool for disaster management including planning of adaptive and mitigation measures by agencies in coastal states.

Integrated Coastal Zone Management (ICZM):

• It is a study and a planning initiative under the World Bank, the first phase of which is Enhancing Coastal Ocean Resource Efficiency (ENCORE).

Integrated Coastal Management Society:

It launches ICZM under four components.

• National Coastal Management Program
• ICZM- West Bengal
• ICZM-Orissa
• ICZM-Gujarat

National Center for Sustainable Coastal Management:

• Established in Chennai to conduct study and research in the field of coastal zone management including coastal resources and environment.

National Action Plan on Climate Change:

• It outlines a strategy that aims to enable the country to adapt to climate change and enhance the ecological sustainability of our development path.

Coastal Regulation Zone:

• It is notified by the Ministry of Environment under the ambit of the Environment Protection Act 1986. It sets guidelines to strike a balance between economic growth and environmental protection.

Coastal Management Information System (CMIS):

• Keeping in view the importance of data collection on coastal processes towards coastal protection measures, a new component “Coastal Management Information System (CMIS)” was introduced under the Central Sector Plan Scheme “Development of Water Resources Information System”.

CMIS is a data collection activity used to gather coastal data that can be used in planning, design, construction and maintenance of site specific coastal protection structures in vulnerable coastal stretches.