Q.Explain the causes and effects of coastal erosion in India. What are the available coastal management techniques for combating the hazard?

Body

graph TD
    GW["Groundwater Extraction"] --> CE["Causes of Coastal Erosion"]
    NWA["Natural Wave Action"] --> CE
    SLR["Sea-Level Rise"] --> CE
    SC["Storms and Cyclones"] --> CE
    HA["Human Activities"] --> CE
    VD["Vegetation Destruction"] --> CE

Causes of Coastal Erosion in India

1. Natural Causes

• Wave and Tidal Action: Strong waves and longshore currents continuously scour and transport beach sediments.
• Extreme Weather Events: Severe cyclones and storm surges rapidly accelerate shoreline retreat.
• Sea-Level Rise: Global warming-induced sea-level rise increases coastal submergence and wave reach.
• Sediment Deficit: The construction of upstream dams traps riverine sediments, reducing the natural supply of sand to beaches.

2. Anthropogenic Causes

• Hard Infrastructure: Construction of ports, harbors, breakwaters, and groynes alters natural littoral drift, causing severe erosion downstream.
• Sand Mining: Illegal mining of sand from riverbeds and beaches strips the coast of its natural protective barriers.
• Destruction of Vegetation: Clearing coastal mangroves and sand dune vegetation destabilizes the shoreline.
• Unplanned Development: Rapid urbanization and tourism-driven construction close to the high-tide line put immense pressure on fragile coastal zones.

Effects of Coastal Erosion

1. Loss of Land and Infrastructure

• It leads to the displacement of coastal communities and causes severe structural damage to roads, houses, and ports.
• Example: Coastal villages in Kerala and Tamil Nadu have faced repeated land loss, forcing families to relocate.

2. Livelihood Disruption

• Fisherfolk lose vital space for landing boats and drying nets, while coastal farmers suffer as saltwater intrusion ruins agricultural fields and contaminates local drinking water sources.

3. Ecological Damage

• The destruction of mangroves, sand dunes, and coral reefs severely impacts coastal biodiversity.
• It degrades critical nesting sites for endangered marine species, such as Olive Ridley turtles.

Coastal Management Techniques

1. Hard Engineering Methods

• Seawalls and Groynes: Massive concrete or rock structures built parallel or perpendicular to the shore to absorb wave energy. However, they often shift erosion problems to adjacent areas.
• Breakwaters: Offshore barriers constructed to reduce wave energy before it reaches the shoreline.
• Example: Seawalls deployed along the coasts of Mumbai and Chennai to protect urban infrastructure.

2. Soft Engineering Methods

• Beach Nourishment: Artificially adding large quantities of sand to eroded beaches to restore their natural profile.
• Vegetation Planting: Restoring mangroves and planting dune grasses (like Spinifex) to naturally bind the soil and buffer wave energy.
• Example: Extensive mangrove restoration initiatives in the Sundarbans of West Bengal.

3. Managed Retreat

• A long-term strategy that involves moving human settlements and infrastructure away from highly vulnerable, low-value coastal zones, allowing the shoreline to adjust naturally.

4. Integrated Coastal Zone Management (ICZM)

• A comprehensive, multi-sectoral approach that balances environmental, social, and economic goals to manage coastal resources sustainably.
• Example: The World Bank-assisted ICZM project implemented by MoEFCC in Gujarat, Odisha, and West Bengal.