💥UPSC 2027,2028 Mentorship (April Batch) + Access XFactor Notes & Microthemes PDF

Type: Prelims Only

  • Wetland Conservation

    Sustainable Aquaculture in Mangrove Ecosystems (SAIME) Initiative

    Why in the News?

    The SAIME Initiative, developed by the Nature Environment and Wildlife Society (NEWS) in the Sundarbans of West Bengal, has been conferred Global Technical Recognition by the Food and Agriculture Organization (FAO) of the United Nations.

    What is SAIME Initiative?

    • Concept: A multi-stakeholder partnership model integrating shrimp aquaculture with mangrove restoration in the Sundarbans.
    • Implementing Agencies: Developed by the Nature Environment and Wildlife Society (NEWS) with support from the Global Nature Fund (Germany), Naturland, and Bangladesh Environment & Development Society (BEDS).
    • Purpose: Promotes climate-adaptive, conservation-linked livelihoods balancing ecological health with local economic growth.
    • Implementation: Covers 29.84 hectares with 42 fish farmers, achieving 100% rise in net profits through low-input, eco-friendly methods.
    • Target Group: Focuses on climate-vulnerable coastal communities, encouraging chemical-free shrimp farming to build coastal resilience.

    Core Features and Approach:

    • Ecosystem Integration: Maintains 5–30% mangrove cover within aquaculture ponds, directly linking productivity with ecosystem restoration.
    • Community Participation: Adopts a bottom-up co-management model, involving local farmers in planning, monitoring, and benefit-sharing.
    • Sustainable Practices: Utilises mangrove litter as shrimp feed, cutting chemical dependence and improving natural nutrient cycles.
    • Climate Resilience: Mitigates cyclones, salinity intrusion, and erosion, functioning as a nature-based adaptation system.
    • Economic Efficiency: Promotes low-input, high-yield aquaculture, enhancing smallholder profitability and resource efficiency.
    • Environmental Benefits: Supports carbon sequestration, biodiversity conservation, and blue carbon economy objectives.
    • Global Alignment: Advances SDG-13 (Climate Action), SDG-14 (Life Below Water), and SDG-15 (Life on Land) through integrated coastal sustainability.

    About the Sundarbans:

    Sustainable Aquaculture in Mangrove Ecosystems (SAIME) Initiative

    • Location: Situated in the South and North 24-Parganas districts of West Bengal, at the southern tip of the Gangetic Delta, where the Ganga, Brahmaputra, and Meghna rivers meet the Bay of Bengal.
    • Area: Currently spans 2,585.89 sq km, with an expansion proposal to 3,629.57 sq km, making it the largest mangrove forest in the world.
    • Status: Designated as a Tiger Reserve, National Park, Biosphere Reserve, and a UNESCO World Heritage Site (since 1987).
    • Topography: Characterised by a dense network of tidal creeks, estuaries, and 105 mangrove-covered islands, influenced by daily tidal inundation.
    • Flora and Fauna:
      • Flora: Dominated by Avicennia, Rhizophora, Sonneratia, and Heritiera species.
      • Fauna: Includes Royal Bengal Tiger, Fishing Cat, Estuarine Crocodile, Irrawaddy Dolphin, King Cobra, and several endangered bird species.
    • Boundaries:
      • East: Bangladesh border (Raimangal & Harinbhanga rivers)
      • South: Bay of Bengal
      • North/West: Matla, Bidya, and Gomdi rivers
    • Ecological Importance: Acts as a natural shield against cyclones and tsunamis, a carbon-rich ecosystem, and a vital nursery ground for fisheries — forming the ecological heart of India’s blue economy and coastal resilience framework.

     

    [UPSC 2023] Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?

    Options: (a) Bhitarkanika Mangroves

    (b) Marakkanam Salt Pans

    (c) Naupada Swamp

    (d) Rann of Kutch*

     

  • Indian Missile Program Updates

    Akash Missile System 

    Why in the News?

    India has pitched for the supply of the Akash missile system to Brazil.

    akash

    About Akash Missile System:

    • Overview: Developed by the Defence Research and Development Organisation (DRDO) and manufactured by Bharat Dynamics Ltd (BDL).
    • Type: A short-range Surface-to-Air Missile (SAM) designed to defend against aircraft, UAVs, and helicopters.
    • Operational Users: Inducted by both the Indian Army and the Indian Air Force, forming part of India’s layered air defence grid.
    • Purpose: Protects vital assets from aerial threats within the short to medium range segment.
    • Deployment Mode: Mounted on mobile launchers for rapid positioning, flexibility, and operational agility.
    • Comparison: Functionally comparable to Israel’s Iron Dome, though Akash focuses on intercepting larger aerial targets rather than small projectiles.

    Key Features:

    • Range & Altitude: Effective range 4.5–25 km; altitude coverage 100 m–20 km.
    • Engagement Capacity: A single firing unit can engage four targets simultaneously in both autonomous and group modes.
    • Speed & Accuracy: Capable of high-speed interceptions with radar-guided precision.
    • Propulsion & Dimensions: Length 5.87 m, diameter 350 mm, weight 710 kg; powered by solid-fuel propulsion.
    • Automation: Fully automated system ensuring rapid reaction time from detection to neutralization.
    • ECCM Capability: Built-in Electronic Counter-Counter Measures (ECCM) to resist enemy jamming
    [UPSC 2023] Consider the following statements:

    1. Ballistic missiles are jet-propelled at subsonic speeds throughout their fights, while cruise missiles are rocket-powered only in the initial phase of flight.

    2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

    Which of the statements given above is/are correct?

    Options: (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2*

     

  • ISRO Missions and Discoveries

    Mission Drishti: World’s First Multi-sensor EO Satellite

    Why in the News?

    Indian space-tech start-up GalaxEye, based in Bengaluru, has announced the upcoming launch of Mission Drishti, the world’s first multi-sensor Earth Observation (EO) satellite, in the first quarter of 2026.

    About Mission Drishti:

    • Objective: To provide high-resolution, real-time geospatial intelligence for governments, defence, and industries across critical domains such as disaster management, infrastructure, agriculture, and national security.
    • Developer: Conceived by Bengaluru-based GalaxEye Space, an Indian space-tech start-up founded by IIT Madras alumni.
    • Nature: World’s first multi-sensor Earth Observation (EO) satellite, capable of integrating multiple imaging technologies on a single platform.
    • Launch Timeline: Scheduled for first quarter of 2026, serving as the first step in GalaxEye’s plan to deploy a constellation of 8–12 satellites by 2029.
    • Innovation: Combines Synthetic Aperture Radar (SAR) and optical sensors for multi-dimensional imaging across all weather and lighting conditions.
    • Significance: Marks India’s largest privately built satellite and establishes India’s position in the global EO market with indigenous, high-precision imaging technology.

    Key Features:

    • Multi-Sensor Payload: Integrates SAR and optical imaging systems on one platform, a first in global satellite technology.
    • Resolution and Capacity: Offers 1.5-metre resolution, providing ultra-clear imagery for tactical and analytical applications.
    • All-Weather Operation: SAR enables imaging day and night, through cloud cover and adverse weather, ensuring continuous monitoring capability.
    • Satellite Specifications: Weighs 160 kg, making it India’s heaviest privately developed EO satellite, designed for spatial, spectral, and temporal precision.
    • Constellation Vision: Part of GalaxEye’s long-term plan to deploy 8–12 satellites by 2029 for near-real-time global coverage.
    • Applications: Defence surveillance, disaster management, infrastructure auditing, agriculture analytics, and environmental monitoring.
    [UPSC 2019] For the measurement/estimation of which of the following are satellite images/remote sensing data used?

    1. Chlorophyll content in the vegetation of a specific location 2. Greenhouse gas emissions from rice paddies of a specific location 3. Land surface temperatures of a specific location

    Select the correct answer using the code given below.

    Options: (a) 1 only (b) 2 and 3 only (c) 3 only (d) 1, 2 and 3*

     

  • Indian Missile Program Updates

    DRDO to extend Astra Mark 2’s range to 200 km

    Why in the News?

    The Defence Research and Development Organisation (DRDO) is developing an extended-range variant of the Astra Mark 2 beyond-visual-range (BVR) air-to-air missile.

    Astra Mark 2 Missile:

    • Overview: An indigenously developed Beyond Visual Range (BVR) air-to-air missile by the DRDO, enhancing the Indian Air Force’s long-range interception capability.
    • Lineage: Successor to Astra Mark 1 (range ~100 km); marks a leap in India’s self-reliance in advanced air combat systems.
    • Integration: Compatible with Su-30 MKI and LCA Tejas, with future integration planned for Rafale, AMCA, and TEDBF.
    • Industry Collaboration: Co-developed with over 50 industries, including Hindustan Aeronautics Limited (HAL) and Bharat Dynamics Limited (BDL).

    Key Features:

    • Dual-Pulse Propulsion: Incorporates dual-pulse solid rocket motor (vs. single-pulse in Mk-1) for sustained thrust and high terminal energy.
    • Range & Speed: Operational range of 150–200+ km, speed up to Mach 4.5, enabling engagement of fast aerial targets.
    • Guidance & Seeker: Equipped with indigenous RF seeker and Electronic Counter-Countermeasures (ECCM) for precision and survivability.
    • All-Weather & Agile: Works in day/night, adverse conditions; supports off-boresight targeting and mid-course data-link updates.
    • Stealth & Safety: Uses smokeless propulsion for reduced detectability during launch.

    Recent Upgrade:

    • Extended Range Variant: DRDO developing version exceeding 200 km, beyond initial 160 km design.
    • Strategic Parity: Comparable to Chinese PL-15 and US AIM-120D AMRAAM, reinforcing India’s deterrence capability.
    • Future Roadmap: Forms baseline for Astra Mark 3, featuring solid-fuel ducted ramjet propulsion, under Atmanirbhar Bharat in advanced missile systems.
    [UPSC 2023] Consider the following statements

    1. Ballistic missiles are jet-propelled at subsonic speeds throughout their fights, while cruise missiles are rocket-powered only in the initial phase of fight.

    2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

    Which of the statements given above is/are correct?

    (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2 *

     

  • Dams and Hydroprojects

    Naying Hydroelectric Project

    Why in the News?

    The Naying Hydroelectric Project (1000 MW), proposed on the Siyom (Yomgo) River in Shi-Yomi district, Arunachal Pradesh, represents a major addition to India’s clean energy expansion under the Decade of Hydro Power (2025–35).

    About Siyom (Yomgo) River:

    • Geography: A right-bank tributary of the Brahmaputra, flowing entirely within Arunachal Pradesh.
    • Origin & Course: Arises in West Siang, travels ~170 km, and joins the Brahmaputra near Assam.
    • Ecology: Basin supports rich biodiversity, agro-pastoral livelihoods, and lies within the Eastern Himalaya Biodiversity Hotspot.
    • Protected Areas: Mouling National Park lies on its eastern bank, part of the Dibang–Siang biosphere landscape.
    • Hydrological Role: Ensures irrigation, microclimate regulation, and provides run-of-the-river potential for clean energy, though demanding careful ecosystem balance.

    About Naying Hydroelectric Project:

    • Overview: A proposed 1,000 MW (4×250 MW) run-of-the-river project located in Shi-Yomi district, Arunachal Pradesh.
    • Developers: Jointly undertaken by North Eastern Electric Power Corporation (NEEPCO) and Arunachal Pradesh Hydropower Corporation Ltd (APHCL).
    • Design & Output: Features a concrete dam, underground powerhouse, and diversion tunnels, expected to generate 4,966.77 GWh annually.
    • Regulatory Approval: Received Central Electricity Authority (CEA) concurrence in 2013; progress slowed by environmental and social concerns.
    • Public Consultation: Environmental hearing scheduled for 12 November 2025 at Yapik Community Hall to assess ecological and community impacts.
    • Timeline: Construction targeted to start by 2028, with commissioning by 2032.
    • Policy Context: Forms part of the state’s Decade of Hydro Power (2025–2035), aiming for 19 GW capacity addition to support India’s net-zero goals.
    • Regional Linkages: Among five key hydel projects in the region – Heo (240 MW), Hirong (500 MW), Tato-I (186 MW), and Tato-II (700 MW).
    [UPSC 2022] Consider the following pairs:

    Reservoirs – States

    1. Ghataprabha — Telangana

    2. Gandhi Sagar — Madhya Pradesh

    3. Indira Sagar — Andhra Pradesh

    4. Maithon —Chhattisgarh

    Options:

    (a) Only one pair (b) Only two pairs (c) Only three pairs (d) All four pairs”

     

  • Air Pollution

    Graded Response Action Plan (GRAP)

    Why in the News?

    The Commission for Air Quality Management (CAQM) has invoked Stage I of the Graded Response Action Plan (GRAP) across the Delhi–NCR as air quality slipped into the ‘poor’ category (AQI 211) after more than three months.

    What is Air Quality Index (AQI)?

    • Purpose: Quantifies pollution levels and health impact using major pollutants — PM₂․₅, PM₁₀, SO₂, NO₂, CO, O₃, NH₃, Pb.
    • Scale:
      1. 0–50 = Good
      2. 51–100 = Satisfactory
      3. 101–200 = Moderate
      4. 201–300 = Poor
      5. 301–400 = Very Poor
      6. 401–450 = Severe
    • >450 = Severe Plus
    • Interpretation: Higher AQI ⇒ greater exposure risk, particularly for children, elderly, and respiratory patients.

    About Graded Response Action Plan (GRAP):

    • Objective: To ensure anticipatory, graded, and region-wide responses that reduce PM₂․₅ and PM₁₀ concentrations, controlling emissions from vehicles, dust, and industries.
    • Coverage: Applies across Delhi, Haryana, Uttar Pradesh, Rajasthan, and other NCR districts, ensuring uniform regional implementation.
    • Legal Mandate: Issued under Section 5 of the Environment (Protection) Act, 1986, binding on all NCR states and agencies.
    • Genesis: Approved by the Supreme Court in 2016 (M.C. Mehta vs. Union of India) and notified in Jan 2017 by MoEFCC under the Environment (Protection) Act, 1986.
    • Implementation: Initially enforced by EPCA (till 2020); now implemented by the Commission for Air Quality Management (CAQM) established via ordinance in Oct 2020.
    • Functioning: CAQM works with CPCB, IMD, and IITM Pune, which provide forecast-based modelling for pre-emptive action.
    • Key Stages of Action:
      1. Stage I (Poor: 201–300): Road sweeping, water sprinkling, dust control at sites, solid-waste removal, old-vehicle enforcement.
      2. Stage II (Very Poor: 301–400): Hotspot regulation, DG set restrictions, enhanced public transport.
      3. Stage III (Severe: 401–450): Ban on BS-III petrol & BS-IV diesel cars, construction halt, school closures.
      4. Stage IV (Severe+ >450): Complete construction ban, truck entry restriction (essentials exempted), curbs on non-essential vehicles.
    [UPSC 2024] According to the Environmental Protection Agency (EPA), which one of the following is the largest source of sulphur dioxide emissions?

    Options: (a) Locomotives using fossil fuels

    (b) Ships using fossil fuels

    (c) Extraction of metals from ores

    (d) Power plants using fossil fuels*

     

  • Judicial Reforms

    Legal Information Management and Briefing System (LIMBS)

    Why in the News?

    The Department of Legal Affairs, Ministry of Law and Justice, inaugurated the “Live Cases” Dashboard under the Legal Information Management and Briefing System (LIMBS) at Shastri Bhawan, New Delhi.

    About LIMBS Portal:

    • Overview: A centralised, web-based litigation management platform developed by the Department of Legal Affairs, Ministry of Law & Justice, under the Digital India initiative.
    • Purpose: Enables real-time monitoring, coordination, and analysis of court cases involving the Union of India, covering all ministries, PSUs, and autonomous bodies.
    • Design & Function: Serves as a single digital interface connecting nodal officers, legal cells, and advocates for streamlined case management and reduced duplication.
    • Policy Alignment: Implements the Prime Minister’s directive to minimise government litigation, improve inter-ministerial coordination, and enhance transparency and efficiency.
    • Scale (2025): Tracks 7.23 lakh live cases from 53 ministries/departments; over 13,000 ministry users and 18,000 advocates actively update records.
    • Integration: Linked with national judicial databases for automated case updates and status tracking.

    Key Features:

    • Dashboard Monitoring: Real-time visual dashboard showing ministry-wise pending, disposed, and contempt cases for trend analysis.
    • Court Connectivity: Integration with the Supreme Court, 25 High Courts, District Courts, and 9 Tribunals for live order retrieval.
    • Advanced Search: Multi-parameter filtering by court, advocate, ministry, judgment date, or financial value.
    • User Hierarchy: Tiered access for Nodal Officers, Admins, and Advocates ensuring accountability and data integrity.
    • Document & Fee Management: Digital upload of pleadings, notices, and advocate bills for secure, paperless workflow.
    • Accessibility & Security: 24×7 open-source platform with cybersecurity compliance and uninterrupted access.
  • ISRO Missions and Discoveries

    Crew Escape System (CES) in the Gaganyaan Mission

    Why in the News?

    The Crew Escape System is ISRO’s most critical safety innovation for Gaganyaan. This newscard is an excerpt from the original article published in The Hindu.

    Back2Basics: Gaganyaan Mission:

    • Overview: India’s first human spaceflight mission, initiated in 2007, to send 3 astronauts into Low Earth Orbit (400 km) for 3 days, followed by Arabian Sea splashdown.
    • Rocket: Human-Rated LVM3 (HLVM3), adapted from GSLV Mk3, certified in 2025 for safe human use.
    • Significance: India to become the 4th nation (after US, Russia, China) with crewed spaceflight capability.
    • Latest Timeline (as of Sept 2025):
      • Dec 2025: First uncrewed mission (G1) with humanoid Vyommitra.
      • 2026: Two more uncrewed flights for life-support, avionics, and escape tests.
      • Early 2027: First crewed mission – 3 astronauts in orbit for 3 days.
    • Progress so far:
      • 80–85% development complete: avionics, parachutes, crew safety systems validated.
      • Integrated Air Drop Test (Aug 2025): Confirmed crew module deceleration.
      • Crew Escape System: Multiple ground and flight tests successful.
      • Recovery: Indian Navy and Australian Space Agency conducting splashdown drills.
      • Four IAF test pilots shortlisted: Shubhanshu Shukla, Prasanth Balakrishnan Nair, Angad Pratap, Ajit Krishnan.
      • All trained in Russia, now in advanced Indian training. Final crew of three will be chosen for maiden flight.

    What is Crew Escape System (CES)?

    • Purpose: A critical safety mechanism in ISRO’s Gaganyaan Mission, enabling astronaut rescue in case of launch vehicle failure during the atmospheric ascent phase.
    • Placement & Function: Mounted atop the Human-Rated LVM3 (HLVM3) rocket; rapidly separates the crew module and propels it to safety using high-thrust solid motors.
    • Performance: Escape motors generate acceleration up to 10 g, using high burn-rate propellants for faster thrust than the launcher. Astronauts withstand this briefly in a “child-in-cradle” posture.
    • Safety Systems: Incorporates redundant subsystems, heritage-based design, and real-time health monitoring through the Integrated Vehicle Health Management (IVHM) network for millisecond-level response.
    • Types of CES:
      1. Puller-Type: Used in Gaganyaan; solid-fuel motors pull the crew module away. Also adopted by Russia’s Soyuz, China’s Long March, and US Saturn V missions.
      2. Pusher-Type: Used in SpaceX Crew Dragon (Falcon 9); liquid-fuel thrusters push the capsule away.
    • Comparison: Puller systems suit high-thrust, short-duration extractions; pusher systems integrate better with reusable modules.

    Operational Sequence & Recovery:

    1. Automatic Activation: On anomaly detection, IVHM triggers CES instantly; escape motors fire, propelling the crew module clear of the rocket.
    2. Separation & Descent: After reaching safe distance, CES detaches and the module descends under multistage parachutes, drogue, main, and reserve, ensuring controlled speed and stability.
    3. Splashdown & Safety: The module lands in the sea, impact forces within safe physiological limits, allowing quick recovery.
    4. Significance: Serves as the core life-saving system of India’s human spaceflight programme, ensuring crew survival during catastrophic launch failures.
    [UPSC 2025] Consider the following space missions:

    I. Axiom-4 II. SpaDeX III. Gaganyaan

    How many of the space missions given above encourage and support microgravity research?

    (a) Only one (b) Only two (c) All three* (d) None

     

  • Climate Change Impact on India and World – International Reports, Key Observations, etc.

    What are Climate Tipping Points?

    Why in the News?

    The Global Tipping Points Report (2025), authored by 160 scientists from 23 countries, warns that warm-water coral reefs have already crossed their thermal tipping point, triggering irreversible dieback.

    About Tipping Points:

    • Overview: Tipping Points are critical thresholds in Earth’s natural and climate systems beyond which self-reinforcing and often irreversible changes occur.
    • Mechanism: Once crossed, feedback loops accelerate transformation — e.g., melting permafrost releases methane, which increases warming and causes more melting.
    • Irreversibility: Even if greenhouse gas emissions are later reduced, many systems cannot revert to their original stable state.
    • Significance: Tipping Points determine long-term planetary stability, climate predictability, and biosphere resilience.

    Important Definitions:

    • Climate Tipping Point (IPCC): A critical threshold at which small changes in temperature or forcing cause a large, often irreversible shift in a climate subsystem.
    • Feedback Loop: A process where an initial change triggers further effects that amplify the original disturbance (positive feedback).
    • Hysteresis: The property of a system where reversing to its prior state requires conditions much different from those that caused the initial change.
    • Cascade Effect: A phenomenon where crossing one tipping point triggers others in connected Earth systems, leading to compounded impacts.
    • Thermal Tipping Point (for Coral Reefs): The temperature threshold (~1.2°C above pre-industrial) beyond which coral survival and recovery become impossible.

    Key Global Tipping Points Identified:

    • Ice Sheets: Collapse of Greenland and West Antarctic ice sheets, committing the planet to multi-metre sea-level rise.
    • Coral Reefs: Permanent dieback of warm-water reefs due to ocean warming and acidification, destroying marine biodiversity.
    • Amazon Rainforest: Shift toward a savannah ecosystem, reducing carbon storage and regional rainfall.
    • Atlantic Meridional Overturning Circulation (AMOC): Potential shutdown below 2°C, disrupting global heat distribution and monsoon patterns.
    • Permafrost Thaw: Release of methane and CO, reinforcing global warming.
    • Boreal Forests & Mountain Glaciers: Increased risk of widespread dieback and loss of freshwater reserves.
    • Sub-Polar Gyre (SPG): Destabilization in North Atlantic circulation, altering marine ecosystems and heat flow.

    Highlights from the Latest Reports (Global Tipping Points 2025):

    • Study Scale: Conducted by 160 scientists from 23 countries, assessing multiple Earth-system thresholds.
    • Coral Crisis: Since January 2023, 84.4% of coral reefs across 82 nations have suffered bleaching — marking the fourth global mass event, the worst on record.
    • Temperature Thresholds: Exceeding 1.5°C global warming risks triggering multiple tipping points; 1.2°C already breached for warm-water reefs.
    • AMOC Collapse Risk: Could occur below 2°C, potentially plunging northwest Europe into severe winters and disrupting global food and water systems.
    • Amazon Dieback: Widespread collapse possible below 2°C, directly affecting 100+ million people dependent on its ecosystem.
    • Interconnected Risk: Earth’s systems form a tipping network — crossing one threshold may accelerate others, creating a domino-like cascade.
    • Policy Warning: Current Paris Agreement pledges and net-zero targets are inadequate to limit warming below 2°C.
    [UPSC 2024] One of the following regions has the world’s largest tropical peatland, which holds about three years’ worth of global carbon emissions from fossil fuels, and the possible destruction of which can exert a detrimental effect on the global climate.

    Which one of the following denotes that region?

    Options: (a) Amazon Basin (b) Congo Basin* (c) Kikori basin (d) Rio De La Plata Basin

     

  • Global Geological And Climatic Events

    Delhi Morphological Ridge

    Why in the News?

    The Delhi government has decided to declare 41 sq. km of the Southern Ridge as a reserved forest under the Indian Forest Act, 1927, following long-pending directions from the National Green Tribunal (NGT).

    Delhi Morphological Ridge

    About Delhi Morphological Ridge:

    • The Delhi Ridge is the northern extension of the ancient Aravalli Range, stretching approximately 35 km from Tughlaqabad to Wazirabad, along the Yamuna River.
    • It is composed mainly of quartzite rock, is over 1.5 billion years old, and significantly older than the Himalayas.
    • It functions as Delhi’s green lungs, aiding in carbon sequestration, temperature regulation, and air pollution reduction.
    • It acts as a natural barrier against desert winds from Rajasthan and supports rich biodiversity, making Delhi one of the world’s most bird-rich capitals.
    • It is divided into four zones: Northern Ridge, Central Ridge, South-Central Ridge, and Southern Ridge.
    • Key conservation areas include the Northern Ridge Biodiversity Park and the Asola Bhatti Wildlife Sanctuary.

    Land Use Regulation in the Ridge:

    • Although the area shares ecological features with the Delhi Ridge, it is NOT officially notified as forest land, but it enjoys judicial protection.
    • A 1966 directive prohibits any NON-forest use or encroachment without court approval.
    • Any change in land use must be cleared by the Ridge Management Board (RMB) and the Supreme Court-appointed Central Empowered Committee (CEC).
    • The area is mapped using data from the Delhi Forest Department and the 2006 Seismic Zonation Map.
    • Formal notification as a Reserved Forest under the Indian Forest Act, 1927, is pending due to the absence of ground-truthing.
    • In revenue records, it is often marked as “gair mumkin pahad”, meaning uncultivable rocky hill.
    • The terrain is ecologically fragile, with shallow soil and rocky outcrops, making it unsuitable for construction.
    [UPSC 2001] The approximate age of the Aravalli range is-

    Options: (a) 370 million years (b) 470 million years (c) 570 million years (d) 670 million years