UPSC CSE Prelims
Natural Resources & Conservation 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 1 — 1, 3 and 4 only

Nitrogen-fixing plants have a symbiotic relationship with rhizobia bacteria in their root nodules, which convert atmospheric nitrogen into forms usable by the plant. Among the listed options, only Alfalfa (1), Chickpea (3), and Clover (4) are leguminous nitrogen-fixing plants. Amaranth, Purslane (Kulfa), and Spinach are non-leguminous plants that depend on soil nitrogen and cannot fix atmospheric nitrogen.

✅ Statement 1 (Alfalfa) – Correct: Alfalfa is a legume with nitrogen-fixing capability through symbiotic rhizobia bacteria.
❌ Statement 2 (Amaranth) – Incorrect: Amaranth is a leafy vegetable that requires soil nitrogen and lacks nitrogen-fixing ability.
✅ Statement 3 (Chickpea) – Correct: Chickpea (a legume) has root nodules with nitrogen-fixing bacteria.
✅ Statement 4 (Clover) – Correct: Clover is a well-known leguminous nitrogen-fixer used in crop rotation and soil improvement.
❌ Statement 5 (Purslane/Kulfa) – Incorrect: Purslane is a succulent weed that does not fix nitrogen.
❌ Statement 6 (Spinach) – Incorrect: Spinach is a leafy vegetable requiring nitrogen from soil or fertilizers.

📝 Short Notes: Nitrogen-Fixing Plants

• Nitrogen Fixation: The process of converting atmospheric nitrogen (N₂) into ammonia or nitrates usable by plants, primarily performed by nitrogen-fixing bacteria.
• Symbiotic Nitrogen Fixation: Leguminous plants (family Fabaceae/Leguminosae) form symbiotic relationships with rhizobia bacteria in root nodules to fix nitrogen.
• Common Nitrogen-Fixing Plants: Include legumes like alfalfa, chickpea, clover, peas, beans, lentils, soybeans, and peanuts.
• Agricultural Importance: Nitrogen-fixing crops reduce the need for synthetic nitrogen fertilizers, improve soil fertility, and are commonly used in crop rotation systems.
• Non-Nitrogen-Fixing Plants: Most cereals, vegetables, and non-leguminous plants (like amaranth, spinach, purslane) cannot fix nitrogen and depend on soil nitrogen content.
• Elimination Strategy: Knowing that purslane is a common weed helps eliminate options containing it, as weeds typically do not have specialized nitrogen-fixing mechanisms.

Detailed Explanation:

Answer: Option 2 — 3, 4 and 5

This question tests knowledge about Moringa (drumstick) and Tamarind trees, their characteristics, economic uses, and potential applications. Out of the five statements, only statements 3, 4, and 5 are correct regarding tamarind collection as minor forest produce, India's exports, and biofuel potential of both plants' seeds.

❌ Statement 1 – Incorrect: Moringa oleifera is a deciduous tree (not evergreen) and belongs to family Moringaceae (not a legume; it lacks nitrogen-fixing root nodules).

❌ Statement 2 – Incorrect: Tamarind (Tamarindus indica) is native to tropical Africa, not endemic to South Asia, though it is widely naturalized in India.

✅ Statement 3 – Correct: Tamarind is collected as Minor Forest Produce (MFP) in India and provides livelihood to tribal and forest-dwelling communities.

✅ Statement 4 – Correct: India is a major exporter of both tamarind and moringa seeds (valued for oil content and medicinal properties).

✅ Statement 5 – Correct: Moringa seeds contain 30-40% oil suitable for biodiesel production, and tamarind seed oil is also being researched for biofuel applications.

📝 Short Notes: Moringa and Tamarind

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:

Answer: Option 2 — 2 and 3 only

Heavy sand mining in riverbeds disrupts the natural filtration system and hydrological balance, leading to groundwater pollution and lowering of water tables. It does not decrease salinity; rather, in coastal areas, it can increase salinity through saltwater intrusion.

❌ Statement 1 – Incorrect: Sand mining does not decrease salinity; in coastal/estuarine regions, it actually increases salinity by allowing saltwater intrusion from the sea into the river system.

✅ Statement 2 – Correct: River sand acts as a natural filter; its removal reduces filtration capacity, allowing pollutants, heavy metals, and contaminants to seep into groundwater aquifers.

✅ Statement 3 – Correct: Heavy sand mining causes riverbed incision (deepening), which lowers the base level, causing surrounding groundwater to drain into the deepened channel and significantly lowering the water table in adjacent areas.

📝 Short Notes: Environmental Impacts of Sand Mining

• Riverbed Incision: Excessive sand extraction deepens river channels, destabilizing riverbeds and banks, leading to erosion and infrastructure damage (bridges, pipelines).
• Groundwater Depletion: Lowered riverbeds act as drains, pulling down the surrounding water table and affecting wells and agriculture in riparian zones.
• Loss of Natural Filtration: Sand and gravel layers naturally filter water; their removal compromises water quality and increases groundwater contamination risk.
• Saltwater Intrusion: In coastal areas, sand mining creates depression zones that facilitate inland movement of saline water, contaminating freshwater resources.
• Biodiversity Loss: Sand mining destroys aquatic habitats, spawning grounds for fish, and nesting sites for river fauna like turtles and crocodiles.
• Regulatory Framework: Environment (Protection) Act, 1986, and Ministry of Environment guidelines regulate sand mining; many states have banned riverbed sand mining.

Detailed Explanation:

Answer: Option 1 — 1 and 2 only

This question tests knowledge of the Forest Rights Act, 2006, particularly regarding Critical Wildlife Habitats and Habitat Rights for Particularly Vulnerable Tribal Groups (PVTGs). Statement 3 is incorrect because State governments, not the Union Ministry, have the authority to declare Habitat Rights.

✅ Statement 1 – Correct: The Forest Rights Act, 2006 explicitly defines "Critical Wildlife Habitat" as areas within National Parks and Wildlife Sanctuaries that require inviolate conservation for wildlife protection, and can only be declared based on scientific evidence after due process of resettlement.

✅ Statement 2 – Correct: In 2015, the Baiga tribal community in Madhya Pradesh became the first in India to be granted Habitat Rights under the FRA, 2006, allowing them to continue living in the Kanha Tiger Reserve buffer zone with access to forest resources.

❌ Statement 3 – Incorrect: Under the Forest Rights Act, 2006, it is the State governments (not the Union Ministry) that have the authority to declare and vest Habitat Rights for Primitive Tribal Groups after obtaining consent from the concerned communities and establishing resettlement measures.

📝 Short Notes: Forest Rights Act, 2006 — Key Provisions

• Official Title: The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006
• Critical Wildlife Habitat (CWH): Defined under Section 2(b) as areas within National Parks and Wildlife Sanctuaries that require inviolate conservation for wildlife protection; can be notified only after scientific evidence and completion of resettlement process
• Habitat Rights: Under Section 3(1)(e), Primitive Tribal Groups (now called Particularly Vulnerable Tribal Groups - PVTGs) and pre-agricultural communities are entitled to habitat rights for habitation and livelihood
• Authority: State governments have the power to declare Habitat Rights after obtaining consent from Gram Sabhas and affected communities
• First Grant: Baiga tribe in Madhya Pradesh (2015) was the first PVTG to receive Habitat Rights in Kanha Tiger Reserve buffer zone
• PVTGs in India: 75 tribal groups across 18 states are classified as Particularly Vulnerable Tribal Groups based on criteria like pre-agricultural level of technology, low literacy, and declining population

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.