Seawater intrusion in the coastal aquifers is a major concern in India. What are the causes of seawater intrusion and the remedial measures to combat this hazard?(Answer in 150 words)

Introduction

Seawater intrusion refers to the movement of saline seawater into freshwater aquifers in coastal regions.

It occurs when the natural balance between freshwater and seawater is disturbed, leading to the contamination of

groundwater resources. In India, coastal states such as Gujarat, Tamil Nadu, Andhra Pradesh, and West Bengal

face increasing risks due to growing water demand and climate-related factors.

Body

Causes of Seawater Intrusion

• Over-extraction of Groundwater: Excessive pumping for agriculture, industry, and domestic use lowers the freshwater table.

• Rapid Urbanization and Industrialization: Increased water demand in coastal cities intensifies groundwater depletion.

• Reduced Recharge: Decline in rainfall infiltration due to land-use changes and surface concretization.

• Sea-Level Rise: Climate change–induced sea-level rise increases pressure on coastal aquifers (as highlighted in IPCC reports).

• Natural Geological Factors: Permeable coastal sediments allow easier movement of saline water into aquifers.

Remedial Measures

• Regulated Groundwater Extraction: Implement sustainable groundwater management policies.

• Artificial Recharge: Use recharge wells, percolation tanks, and rainwater harvesting structures.

• Subsurface Barriers: Construction of physical barriers to prevent seawater intrusion.

• Desalination and Alternative Water Sources: Reduce pressure on aquifers by using treated surface water or desalinated water.

• Integrated Coastal Zone Management (ICZM): Scientific planning and monitoring of coastal aquifers.

Conclusion

Addressing seawater intrusion requires sustainable groundwater management, improved recharge systems, and climate-resilient policies.

Adopting integrated water resource management will help protect coastal aquifers and ensure long-term water security.