Model Answer
0 min readIntroduction
Groundwater constitutes a significant portion of India’s freshwater resources, accounting for approximately 40% of the total water supply. Understanding the distribution and potential of groundwater is crucial for water security, especially in the context of increasing demand and climate change. India’s diverse geological formations give rise to distinct groundwater provinces, each characterized by unique hydrogeological conditions. These provinces are broadly classified based on geological formations like consolidated and unconsolidated formations, and structural features. A comprehensive assessment of these provinces is essential for effective groundwater management and utilization.
Groundwater Provinces of India
India’s groundwater provinces can be broadly categorized into the following major regions:
1. The North-Western Alluvial Province
This province covers the Indo-Gangetic Plain, encompassing the states of Punjab, Haryana, Uttar Pradesh, and Bihar. It is characterized by thick, unconsolidated alluvial deposits of sand, silt, and clay laid down by the Indus and Ganga river systems.
- Aquifer Characteristics: Highly permeable and productive aquifers due to the presence of sand and gravel layers.
- Hydrogeological Potential: Extremely high groundwater potential, making it the most productive groundwater province in India. However, it faces issues of over-extraction and declining water levels.
- Depth to Water Table: Varies from a few meters to 30 meters in many areas.
2. The Eastern and South-Eastern Coastal Province
This province extends along the eastern and south-eastern coastline, covering states like West Bengal, Odisha, Andhra Pradesh, Tamil Nadu, and parts of Kerala. It is characterized by sedimentary formations, including alluvium, sand dunes, and lateritic deposits.
- Aquifer Characteristics: Aquifers are generally confined and less permeable compared to the North-Western province, with varying degrees of salinity in coastal areas.
- Hydrogeological Potential: Moderate groundwater potential, with localized areas of high productivity. Susceptible to saltwater intrusion in coastal regions.
- Depth to Water Table: Ranges from 2 to 20 meters.
3. The Peninsular Hard Rock Province
This province covers a large portion of the Indian peninsula, including states like Maharashtra, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu, and Kerala. It is characterized by crystalline and metamorphic rocks like granite, gneiss, and schist.
- Aquifer Characteristics: Groundwater occurs in fractures, fissures, and weathered zones within the hard rock formations. Aquifers are generally less permeable and have limited storage capacity.
- Hydrogeological Potential: Low to moderate groundwater potential, highly dependent on rainfall and recharge. Groundwater availability is often localized and unevenly distributed.
- Depth to Water Table: Highly variable, ranging from 5 to 50 meters or more.
4. The Lava Plateau Province (Deccan Traps)
This province covers a significant portion of western and central India, including states like Maharashtra, Gujarat, Madhya Pradesh, and Karnataka. It is characterized by basaltic lava flows of the Deccan Traps.
- Aquifer Characteristics: Groundwater occurs in vesicular cavities, fractures, and weathered zones within the basaltic rocks. Aquifers are moderately permeable and have good storage capacity.
- Hydrogeological Potential: Moderate to high groundwater potential, particularly in areas with extensive fracturing and weathering.
- Depth to Water Table: Ranges from 3 to 25 meters.
5. The Semi-Arid Hard Rock Province
This province covers parts of Rajasthan, Gujarat, and Madhya Pradesh. It is characterized by hard rock formations with limited rainfall and high evaporation rates.
- Aquifer Characteristics: Similar to the Peninsular Hard Rock Province, groundwater occurs in fractures and weathered zones.
- Hydrogeological Potential: Low groundwater potential, with limited recharge and high rates of evaporation.
- Depth to Water Table: Generally deep, ranging from 10 to 60 meters or more.
6. The Himalayan Province
This province encompasses the Himalayan region, characterized by complex geological formations, including sedimentary rocks, metamorphic rocks, and glacial deposits.
- Aquifer Characteristics: Groundwater occurs in porous sediments, fractured rocks, and glacial aquifers.
- Hydrogeological Potential: Moderate to high groundwater potential, particularly in the foothills and valleys. Glacial melt contributes to groundwater recharge.
- Depth to Water Table: Variable, depending on the topography and geological formations.
Hydrogeological Potential – Overall Comment: The North-Western Alluvial Province holds the highest hydrogeological potential, followed by the Lava Plateau Province. The Peninsular Hard Rock and Semi-Arid Hard Rock Provinces have limited potential, while the Coastal and Himalayan Provinces exhibit moderate potential with specific challenges like salinity intrusion and glacial melt dependency respectively. Sustainable groundwater management is crucial across all provinces, considering the increasing demand and climate change impacts.
Conclusion
India’s groundwater provinces exhibit significant diversity in their geological formations and hydrogeological characteristics. While the North-Western Alluvial Province remains the primary source of groundwater, a holistic understanding of all provinces is vital for ensuring water security. Addressing challenges like over-extraction, declining water levels, and water quality degradation through integrated water resource management, artificial recharge, and community participation is crucial for the sustainable utilization of this precious resource. Further research and monitoring are needed to accurately assess groundwater potential and develop effective management strategies.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.