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?
Introduction: Defining Seawater Intrusion and its Significance
Seawater intrusion, the ingress of saline water into coastal freshwater aquifers, degrades groundwater quality and threatens potable water supply in India.
Causes of Seawater Intrusion in Coastal Aquifers
- Over-extraction: Excessive groundwater pumping for agriculture, industry, and domestic needs lowers freshwater levels.
- Sea-Level Rise: Climate change-induced sea-level rise increases saline water pressure.
- Reduced Recharge: Decreased rainfall and altered river flows diminish natural aquifer replenishment.
- Geological Factors: Permeable coastal geology facilitates easier intrusion.
Remedial Measures to Combat Seawater Intrusion
- Managed Aquifer Recharge (MAR): Artificial recharge creates a hydraulic barrier.
- Groundwater Regulation: Strict abstraction limits, permits, and monitoring.
- Physical Barriers: Subsurface dams or injection wells impede saline water.
- Alternative Sources: Desalination and rainwater harvesting reduce groundwater dependency.
- ICZM & Awareness: Integrated Coastal Zone Management and public awareness for sustainable use.
Conclusion: Importance of Integrated Management
An integrated approach, combining technology, stringent policies, and community participation, is crucial for combating this hazard and ensuring coastal water security.
135 words · target ~150
The question requires a direct enumeration and explanation of the causes of seawater intrusion and the remedial measures to combat it.
Suggested structure
Introduction: Defining Seawater Intrusion and its Significance
Causes of Seawater Intrusion in Coastal Aquifers
Remedial Measures to Combat Seawater Intrusion
Conclusion: Importance of Integrated Management
Key points
Causes include excessive groundwater extraction (agriculture, industrial, domestic), sea-level rise due to climate change, reduced freshwater recharge, and geological factors.
Impacts include degradation of groundwater quality, reduced agricultural productivity, and scarcity of potable water.
Remedial measures involve Managed Aquifer Recharge (MAR) or artificial recharge techniques.
Implementation of strict groundwater regulation, abstraction limits, and permits is crucial.
Physical barriers like subsurface dams and adoption of desalination plants for alternative water sources.
Integrated Coastal Zone Management (ICZM) and public awareness campaigns for sustainable water use.
Common mistakes
Failing to define seawater intrusion clearly in the introduction.
Providing generic causes or remedies not specific to coastal aquifers.
Omitting key causes like sea-level rise or over-extraction for agriculture.
Not suggesting practical and implementable remedial measures like MAR or regulatory frameworks.
Difficulty: Medium — The question requires specific knowledge of hydrogeology, environmental degradation, and water resource management, beyond general current affairs. Candidates need to provide precise causes and technical remedial measures.