UPSC CSE Prelims
Water Resources Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 3 — Statement-I is correct but Statement-II is incorrect

This question tests understanding of India's groundwater usage patterns and the primary purposes of extraction. Statement-I correctly cites the UN World Water Development Report 2022 data, while Statement-II incorrectly attributes the high extraction primarily to drinking water and sanitation needs.

✅ Statement-I – Correct: According to the UN World Water Development Report 2022, India extracts approximately 251 km³ of groundwater annually from an estimated 20 million wells and tube wells, which indeed represents more than a quarter (about 25-26%) of the world's total groundwater withdrawal.

❌ Statement-II – Incorrect: While India does need to cater to approximately 18% of the world's population, the major reason for high groundwater extraction is not drinking water and sanitation. Approximately 89% of India's groundwater extraction is used for irrigation purposes, not for drinking water and sanitation. Agriculture is the primary driver of groundwater depletion in India.

📝 Short Notes: India's Groundwater Usage

• Total Annual Extraction: Approximately 251 km³, the highest in the world (>25% of global extraction)
• Sectoral Distribution: ~89% for irrigation, ~9% for domestic use, ~2% for industrial use
• Infrastructure: Over 20 million wells and tube wells across the country
• Critical Concern: Unsustainable extraction rates leading to groundwater depletion, particularly in northwestern and southern India
• Key States Affected: Punjab, Haryana, Rajasthan, Gujarat, Tamil Nadu, and Karnataka face severe groundwater stress
• Recharge Gap: Extraction rates significantly exceed natural recharge rates in many regions, especially in agricultural belts

Detailed Explanation:

Answer: Option 4 — 1 only

The Aral Sea has shrunk immensely due to extensive water diversion for irrigation from its feeder rivers (Amu Darya and Syr Darya) since the 1960s, losing over 75% of its area. The Black Sea, while facing pollution and ecological challenges, has not dried up or shrunk significantly. Lake Baikal experiences natural water level fluctuations but has not undergone severe drying like the Aral Sea.

✅ Statement 1 – Correct: The Aral Sea has shrunk by over 75% since the 1960s due to Soviet-era irrigation projects diverting its feeder rivers.
❌ Statement 2 – Incorrect: The Black Sea faces pollution and oxygen depletion issues but has not experienced significant shrinkage or drying.
❌ Statement 3 – Incorrect: Lake Baikal, the world's deepest freshwater lake, has not dried up or shrunk immensely despite some natural water level variations.

📝 Short Notes: Major Water Bodies Under Environmental Stress

• Aral Sea (Central Asia): Once the world's fourth-largest lake, it has lost ~90% of its volume since 1960 due to Soviet irrigation schemes. This has caused desertification, increased salinity, loss of fisheries, and creation of the Aralkum Desert with toxic dust storms.
• Dead Sea (Middle East): Shrinking at about 1 meter per year due to water diversion from the Jordan River and mineral extraction industries.
• Lake Chad (Africa): Has shrunk by ~90% since the 1960s due to climate change, drought, and irrigation demands from surrounding countries.
• Lake Urmia (Iran): Has lost ~80% of its surface area due to dam construction, agricultural water use, and prolonged drought.
• Lake Baikal (Russia): The world's deepest and oldest freshwater lake, containing ~20% of Earth's unfrozen freshwater. Faces pollution threats but remains stable in size.
• Black Sea: Faces eutrophication, anoxic zones, and pollution but maintains its overall size and water volume.

Detailed Explanation:

Thermal power plants are the maximum consumers of industrial water in India, accounting for approximately 88% of annual industrial water consumption.

Engineering (~5%), Paper & Pulp (~2.3%), and Textiles (~2%) industries consume significantly smaller shares of industrial water, making thermal power the clear frontrunner in industrial water usage.