COASTAL EROSION
The erosion of the coastline refers to the gradual wearing away or removal of land, cliffs, or beaches along the shoreline. It's a natural process driven by various factors such as wave action, currents, tides, wind, and sometimes human activities. Coastal erosion can occur due to:
Wave Action: Waves carry energy that can erode the shoreline by breaking down rocks, cliffs, and beaches.
Currents and Tides: Strong currents and tides can further exacerbate erosion by moving sediment away from the coastline.
Storms and Weathering: Severe storms, high winds, and heavy rainfall can accelerate erosion by intensifying wave action and causing landslides or cliff collapses.
Sea Level Rise: Rising sea levels due to climate change contribute to increased erosion as higher water levels can encroach upon and erode coastal land.
Human Activities: Human intervention like construction, dredging, sand mining, and altering natural coastal features can also accelerate erosion by disrupting natural coastal processes.
Coastal erosion can have significant impacts, including loss of land, damage to infrastructure and property, habitat loss for coastal wildlife, and changes in the shape and structure of coastlines. Efforts to manage and mitigate erosion often involve strategies such as building seawalls, constructing groynes (barriers to trap sand), beach nourishment (adding sand to beaches), and implementing coastal vegetation restoration to stabilize the shoreline and reduce erosion
3.What are the types of coastal erosion?
Coastal erosion can manifest in various forms, each with distinct characteristics and impacts. Here are some common types:
Abrasion: Also known as "corrasion," this occurs when waves carrying sediment or debris continuously hit the shoreline, causing the gradual wearing away of cliffs or rocks.
Attrition: This type of erosion happens when waves force rocks and pebbles against each other, resulting in their gradual breakdown into smaller particles.
Hydraulic Action: Occurs when waves impact cliffs or rocks, exerting pressure and forcing air into cracks. Over time, this repeated action weakens the structure, leading to erosion.
Solution: Primarily affects cliffs made of soluble rock, such as limestone or chalk, where certain minerals dissolve due to the presence of acidic water, gradually wearing away the coastline.
Weathering: While not solely caused by waves, weathering contributes to coastal erosion. It involves the breakdown of rocks or cliffs due to natural elements like rain, wind, and temperature changes.
Mass Movement: Includes processes like landslides, slumping, or rockfalls along the coastline due to gravity, often triggered by heavy rainfall, undercutting of cliffs, or seismic activity.
Longshore Drift: The movement of sediment or sand along the coast caused by waves approaching at an angle. This can lead to the erosion of one part of the coastline and deposition in another area.
Each type of coastal erosion contributes differently to the overall degradation of coastal areas. Understanding these processes helps in developing appropriate strategies for managing and mitigating erosion in specific coastal environments
Coastal erosion can create various landforms and geological features as it reshapes the coastline. Some of the formations resulting from coastal erosion include:
Sea Cliffs: Steep, vertical or near-vertical rock formations formed by the erosion of coastal land by waves, weathering, and other erosive forces.
Caves, Arches, and Stacks: Continuous erosion can create sea caves in cliffs, which might further erode to form arches. When these arches collapse, stacks, isolated vertical columns of rock, are left behind in the water.
Headlands and Bays: Differential erosion can create headlands (prominent coastal landforms that extend into the sea) and bays (curved indentations in the coastline).
Beaches and Sandbars: Erosion and deposition of sediment by waves can form sandy beaches, which act as natural buffers against erosion. Sandbars, shallow underwater ridges made of sand, can also form parallel to the coastline due to wave action.
Spits and Barrier Islands: Longshore drift, the movement of sediment along the coast, can result in the formation of spits (narrow, elongated deposits of sand or shingle) and barrier islands (long, narrow islands parallel to the mainland, separated by a lagoon or bay).
Blowholes: These are openings in cliffs or headlands formed by erosion. When waves crash into these openings, water and air are forced out, creating impressive geysers or spouts.
Coastal erosion is a dynamic process that continuously shapes and reshapes the coastline, leading to the formation of diverse landforms and features over time
5. What are the Factors causing Coastal Erosion?
Coastal erosion is influenced by a combination of natural processes and human activities. Some key factors causing coastal erosion include:
Wave Action: Waves, driven by wind and currents, are a primary force eroding coastlines. The energy carried by waves can break down rocks, cliffs, and beaches over time.
Storms and Weather Events: Severe storms, hurricanes, and cyclones can intensify wave action, causing increased erosion. Strong winds and heavy rainfall can also contribute to erosion by destabilizing coastlines.
Sea Level Rise: Rising sea levels, attributed to climate change, lead to higher water levels along coastlines. This can accelerate erosion by submerging low-lying areas and increasing the force of waves on the shoreline.
Coastal Geology: The type of rock, sediment, or soil present along the coastline influences its susceptibility to erosion. Softer rocks or sediments are more prone to erosion than harder, more resistant materials.
Tides and Currents: Strong tidal currents can transport sediment away from the coast, contributing to erosion. Longshore currents that move parallel to the shoreline can also play a role in shaping coastal erosion patterns.
Human Activities: Certain human actions can exacerbate coastal erosion. Construction of infrastructure along the coast, such as harbors, jetties, or sea walls, can disrupt natural sediment transport, leading to localized erosion. Sand mining, dredging, and the removal of vegetation can also contribute to erosion.
Climate Change: Apart from sea level rise, climate change can impact erosion through changes in weather patterns, increased frequency and intensity of storms, and alterations in coastal ecosystems, all of which can amplify erosion processes.
Land Use Changes: Modifications in land use, such as urban development, deforestation, and agricultural practices, can affect natural drainage patterns and increase sediment runoff into coastal areas, contributing to erosion.
6. What are the Methods for Coastal Protection?
Coastal protection methods aim to manage and mitigate the impacts of erosion and coastal hazards. Several strategies and techniques are employed to safeguard coastlines. Here are some common methods for coastal protection:
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Hard Engineering Structures:
- Sea Walls: Vertical or sloping barriers constructed along the shoreline to absorb wave energy and prevent erosion.
- Revetments: Sloping structures made of rocks or concrete designed to protect embankments from erosion by deflecting wave energy.
- Breakwaters: Offshore barriers built parallel or at an angle to the coast to reduce wave energy and protect harbors or shorelines.
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Soft Engineering and Nature-Based Solutions:
- Beach Nourishment: Adding sand or sediment to beaches to widen them and provide a natural buffer against erosion.
- Dune Restoration: Planting vegetation and restoring sand dunes to act as natural barriers against erosion and storm surges.
- Wetland Restoration: Preserving or restoring coastal wetlands, such as mangroves or salt marshes, which can absorb wave energy and reduce erosion while providing habitats for wildlife
- Moving structures away from the coastline or removing buildings and infrastructure from vulnerable areas to allow natural coastal processes to occur.
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Regulations and Planning:
- Zoning and Land Use Regulations: Implementing regulations to limit development in high-risk erosion areas and encourage sustainable coastal development.
- Coastal Management Plans: Developing comprehensive plans that consider erosion risks, climate change impacts, and sustainable coastal practices
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Erosion Monitoring and Adaptation:
- Monitoring Programs: Implementing systems to monitor coastal erosion rates, sea level rise, and changes in coastal morphology to inform adaptive strategies.
- Adaptive Management: Using collected data to adjust and improve existing coastal protection measures in response to changing coastal conditions
- Engaging communities to raise awareness about coastal hazards, promote sustainable behaviors, and encourage participation in coastal protection efforts
The National Coastal Management Program (NCMP) refers to a comprehensive approach adopted by certain countries to manage and protect their coastal zones effectively. This program typically involves a coordinated and integrated framework aimed at preserving and sustainably managing coastal areas, addressing various challenges such as erosion, habitat degradation, pollution, and climate change impacts.
Key elements and objectives of a National Coastal Management Program often include:
- Formulating policies and guidelines that govern coastal zone management, balancing conservation, development, and sustainability.
- Developing coastal management plans that consider ecological, social, and economic factors, delineating zones for specific activities (residential, recreational, conservation, etc.).
- Involving local communities, governments, industries, environmental organizations, and other stakeholders in decision-making processes related to coastal management.
- Implementing measures to mitigate erosion, protect coastal infrastructure, and manage coastal hazards such as storms and sea-level rise.
- Focusing on preserving biodiversity, protecting habitats, and restoring degraded coastal ecosystems.
- Promoting sustainable practices in coastal areas, including responsible tourism, fisheries management, and reducing pollution.
- Conducting research, gathering data, and establishing monitoring systems to assess the health of coastal ecosystems, erosion rates, and changes in the coastal environment.
- Providing training, resources, and support to local authorities and communities to enable effective coastal management and decision-making.
The specifics of a National Coastal Management Program can vary between countries based on their unique coastal challenges, environmental conditions, socio-economic factors, and policy priorities. The overarching goal is to achieve sustainable and resilient coastal management that balances environmental conservation with socio-economic development
8.National Centre for Coastal Research (NCCR)
The National Centre for Coastal Research (NCCR) is an institution in India dedicated to coastal and marine research. It operates under the Ministry of Earth Sciences, Government of India. The primary objective of the National Centre for Coastal Research is to conduct scientific research, monitor coastal areas, and provide scientific advice and information to support coastal management and policy development in India.
Key areas of focus and activities conducted by the NCCR include:
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Coastal Monitoring: Conducting systematic monitoring of coastal areas to assess changes, erosion rates, shoreline dynamics, and the impact of natural events like cyclones.
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Research and Studies: Undertaking scientific research on various aspects of coastal and marine environments, including biodiversity, ecosystem health, pollution, climate change impacts, and sustainable coastal management practices.
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Data Collection and Analysis: Gathering data related to coastal processes, oceanography, sedimentation, and other factors influencing coastal zones. Analyzing this data helps in understanding and predicting changes in the coastal environment.
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Technology Development: Developing and implementing innovative technologies, tools, and models for coastal monitoring, hazard prediction, and management.
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Policy Support: Providing scientific advice and recommendations to government bodies and policymakers for formulating coastal management policies and strategies.
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Capacity Building and Outreach: Conducting workshops, training programs, and outreach activities to disseminate knowledge and build capacity among stakeholders, including coastal communities, researchers, and government officials.
The NCCR plays a crucial role in advancing scientific knowledge, providing data-driven insights, and supporting evidence-based decision-making for the sustainable management and protection of India's coastal and marine environments
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For Prelims: Indian and World Geography-Physical, Social, Economic Geography of India and the World For Mains: General Studies I: Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features and in flora and fauna and the effects of such changes |
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Previous Year Questions 1.In India, the problem of soil erosion is associated with which of the following? (UPSC CSE 2014)
Select the correct answer using the code given below (a) 1 and 2 only Answer: (b) 2.Which of the following is/are the coastal erosional feature(s)? (UPSC NDA General Ability 2018) 1) Notch 2) Sea Arch 3) Cliff 4) Hook Select the correct answer using the code given below: a.1, 2 and 3 b.2, 3 and 4 c.2 and 3 only d.1 only Answer (a) |
Source: indianexpress
