💥Mains Ready By December. Smash Mains & Smash PYQ Admissions Open

GS Paper: GS1-15.Geographical features and their location- Changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.

  • The groundwater potential of the gangetic valley is on a serious decline. How may it affect the food security of India?

    The Indo-Gangetic Valley is home to one of the world’s most prolific alluvial aquifer systems. Yet, according to the United Nations (2025-26) reports, several regions in this basin have crossed the “groundwater depletion tipping point.”

    Declining groundwater potential

    Nationwide, India extracts approximately 247 BCM of groundwater annually, more than China and the US combined.

    Groundwater storage in the Ganga basin is declining at an average rate of 2.6 cm per year. (CGWB)

    In Punjab and Haryana, nearly 78% of assessment units are categorized as “over-exploited.”

    Reasons Behind the Decline

    Green Revolution Legacy-The shift to High-Yielding Varieties (HYV) required 3-4 times more water than traditional seeds.

    Faulty Cropping Patterns-Cultivation of water-guzzling crops like Paddy in semi-arid regions (Punjab/Haryana) where they are not ecologically suited.

    Energy Subsidies-Free or heavily subsidized electricity leads to “blind pumping” in states like Punjab and Haryana.

    Inadequate Regulation-Under the Indian Easements Act 1882, groundwater is tied to land ownership, allowing landowners to extract unlimited water without legal penalty.

    Rapid urban expansion in cities like Delhi, Kanpur, and Patna has reduced the “pervious” area available for natural recharge.

    Climate Change & Monsoonal Shifts-Erratic rainfall patterns mean shorter, more intense bursts of rain that run off rather than seeping into the ground.

    Inefficient Irrigation-Traditional Flood Irrigation methods result in nearly 40% water wastage through evaporation and runoff.

    Deforestation in Catchment Areas-Loss of forest cover in the Himalayan foothills (Shivaliks) has disrupted the natural hydrological cycle that feeds the Gangetic aquifers.

    Industrial Contamination-Discharge of untreated effluents reduces the “potable” potential of the remaining groundwater.

    Population Pressure-With the IGP being one of the most densely populated regions globally, domestic demand has surged, competing directly with agriculture.

    Impact on Food Security

    Yield Reductions-Studies show a 1-meter decline in the water table can lead to an 8% reduction in food grain production.

    Threat to Staples-Punjab and Haryana provide 50% of India’s rice and 85% of its wheat, depletion here directly threatens the National Buffer Stock.

    Increased Cost of Cultivation-Farmers must drill deeper (up to 300-500 ft) and install expensive submersible pumps, leading to rural indebtedness.

    Punjab and Haryana supply a major portion of wheat and rice for the PDS. Reduced grain output affects government stocks.

    Food Inflation-Reduced supply and higher production costs lead to a spike in market prices, making food unaffordable for the poor.

    Quality Degradation (Nutritional Security)-As water levels drop, concentrations of Arsenic and Uranium increase. These enter the food chain, compromising food safety.

    Land Degradation-Excessive groundwater use leads to soil salinization, turning once-fertile alluvial tracts into barren “Usar” land.

    Reduced Cropping Intensity-Farmers who previously grew three crops a year (Zaid, Kharif, Rabi) are being forced to skip seasons due to dry wells.

    Vulnerability of Small Farmers-While wealthy farmers can afford deeper wells, marginal farmers lose access entirely, leading to “de-peasantization” and migration.

    Climate Instability-Without groundwater, Indian agriculture becomes more dependent on the vagaries of the monsoon.

    Way Forward

    Crop Diversification-Aggressively shifting from Paddy to Millets (Shree Anna), pulses, and oilseeds in over-exploited blocks.

    Micro-Irrigation-Scaling up the “Per Drop More Crop” initiative to make drip and sprinkler irrigation mandatory for water-intensive crops.

    Managed Aquifer Recharge (MAR)-Utilizing the Mission Amrit Sarovar to rejuvenate 75,000+ local ponds to act as recharge pits.

    Power Reforms-Transitioning from free electricity to Direct Benefit Transfer (DBT) for electricity.

    Unified Water Governance-Implementing the Mihir Shah Committee recommendations to merge the CGWB and CWC into a single National Water Commission.

    Community-Led Management-Scaling the Atal Bhujal Yojana model where villagers prepare “Water Security Plans” based on their local water budget.

    Legal Reform-Updating the 19th-century Easement Act to treat groundwater as a “Common Pool Resource” rather than private property.

    Aligning agricultural policies with ecological limits and climate resilience can ensure long term food security.

    Indian Geography

  • How are climate change and the sea level rise affecting the very existence of many island nations? Discuss with examples.

    As per the IPCC, global mean sea level rose by 0.20 m between 1901 and 2018. It has projected a global mean SLR of 1.3 to 1.6 m by 2100 under the high-emission scenario.

    Permanent submergence of land – Eg- Kiribati has already seen two small uninhabited islets (Tebua Tarawa and Abanuea) disappear underwater.

    Coastal erosion – Wave action and storm surges remove shoreline. Eg- Shoreline retreat in the Maldives.

    Salinisation of freshwater lenses – Sea water enters groundwater and contaminates wells leading to drinking water shortage.

    Frequent flooding during high tides and storms can lead to large scale displacement. Eg- “King tide” flooding in Tuvalu.

    Damage to housing and public infrastructure – Eg- Majuro Airport in the Marshall Islands frequently faces flooding

    Loss of agriculture – Salinity affects soil fertility and traditional crops. Eg- Taro cultivation affected in Kiribati and Tuvalu.

    Coral reef degradation – Ocean warming and acidification damage reefs that act as wave barriers. Eg- Coral bleaching in Fiji and Maldives.

    Impact on fisheries – Changes in ocean temperature and reef systems reduce fish catch, impacting livelihood

    Climate-induced migration – Eg- Kiribati purchased land in Fiji for future resettlement.

    Way Forward

    Hard Engineering Measures

    Seawalls to block wave attack.

    Groynes – Trap sand and widen beaches. Eg- Puducherry groyne field.

    Breakwaters – Offshore barriers that reduce wave energy. Eg- Chennai port.

    Revetments – Sloped rock armour to absorb wave impact.

    Soft Engineering Measures

    Mangrove Restoration – Eg- MISHTI-based efforts in Sundarbans.

    Coral and Seagrass Restoration – Eg- Andaman reef rehabilitation.

    Integrated Coastal Zone Management (ICZM)

    Ecosystem-Based Coastal Planning – Combines geomorphology, ecology and socio-economic factors.

    Regulatory Tools (CRZ Norms) – no-development zones and hazard mapping reduce vulnerability.

    Early Warning Systems – INCOIS alerts for timely action.

    Strengthening coastal resilience and climate mitigation is essential to safeguard communities and advance SDG 13 (Climate Action) and SDG 14 (Life Below Water).

    Water

  • ‘Super El Niño’ forms in Pacific: Why 2027 is likely to be the hottest year on record

    Why in the News?

    The emergence of Super El Niño conditions in the equatorial Pacific Ocean has become a major concern because it coincides with India’s crucial southwest monsoon season. The India Meteorological Department (IMD) has officially confirmed the development of El Niño and warned that it is expected to strengthen further during the monsoon months. This

    How Has El Niño Developed During the Current Monsoon Season?

    1. IMD Confirmation: El Niño conditions have officially emerged in the equatorial Pacific Ocean.
    2. Strengthening Trend: IMD expects the phenomenon to intensify further during the ongoing southwest monsoon season.
    3. NOAA Assessment: The US National Oceanic and Atmospheric Administration (NOAA) earlier confirmed El Niño emergence.
    4. Peak Projection: NOAA projects the event to peak during November-January.
    5. Intensity Forecast: The event may approach the “very strong” category.

    ENSO Threshold

    1. Niño 3.4 Region: El Niño is declared when sea surface temperature anomalies exceed +0.5°C in the Niño 3.4 region.
      1. The Niño 3.4 region (5°N-5°S, 170°W-120°W) is the primary equatorial Pacific area used by scientists to monitor, define, and predict the El Niño-Southern Oscillation (ENSO). 
    2. Current Reading: Weekly Niño 3.4 Index reached +0.7°C.
    3. Eastern Pacific Warming: Temperature anomalies reached +2.1°C in the easternmost Pacific region.

    What Makes the Current El Niño Different from Previous Events?

    Emerging “Super El Niño” Concerns

    1. NOAA Forecast: El Niño has officially formed in the tropical Pacific Ocean and is likely to strengthen significantly in the coming months.
    2. Historical Significance: Scientists have projected that the current event could rank among the strongest El Niño episodes recorded since 1950.
    3. Probability Estimate: NOAA estimates a 63% probability that the event will intensify into one of the largest El Niño events in the historical record.
    4. Transition Phase: The current event follows the end of La Niña conditions earlier in 2026.
    5. Global Warning: The UN Secretary-General António Guterres has described the phenomenon as an “urgent climate warning.”

    Why is it Being Called a “Super El Niño”?

    1. Exceptional Ocean Warming: Unusually warm Pacific Ocean temperatures are accelerating ENSO development.
    2. Early Intensification: Forecast models indicate stronger warming developing earlier than normally expected.
    3. Historical Comparison: Scientists have compared the event to major El Niño episodes such as 1982-83, 1997-98 and 2015-16.
    4. Global Temperature Impact: Multiple climate models suggest that 2027 could become the hottest year ever recorded globally.

    What is ENSO and How Does It Operate?

    El Niño-Southern Oscillation (ENSO)

    1. Climate Oscillation: Naturally occurring ocean-atmosphere phenomenon over the central and eastern equatorial Pacific Ocean.
    2. Recurrence: Appears every 2-7 years.
    3. Phases: El Niño, Neutral, and La Niña.

    El Niño

    1. Oceanic Condition: The abnormal warming of surface waters in the central and eastern tropical Pacific Ocean.
    2. Mechanism: Trade winds weaken, allowing warm water to push east toward South America.
    3. Indian Impact: Usually suppresses monsoon rainfall.

    La Niña

    1. Oceanic Condition: The abnormal cooling of surface waters in the central and eastern tropical Pacific Ocean.
    2. Mechanism: Trade winds strengthen, pushing warm water toward Asia and pulling cold water up to the surface off South America.
    3. Indian Impact: Generally supports stronger monsoon rainfall.

    Why Could 2027 Become the Hottest Year on Record?

    Interaction Between El Niño and Global Warming

    1. Natural Climate Driver: El Niño releases large amounts of heat from the Pacific Ocean into the atmosphere.
    2. Anthropogenic Warming: Human-induced greenhouse gas emissions have already raised baseline global temperatures.
    3. Compounding Effect: El Niño adds temporary warming on top of long-term climate change trends.
    4. WMO Forecast: Above-average global temperatures are expected between June and August, with effects continuing through November.

    Climate Consequences

    1. Temperature Extremes: Higher likelihood of record-breaking temperatures globally.
    2. Heatwaves: Increased frequency and intensity across multiple continents.
    3. Hydrological Extremes: Simultaneous occurrence of droughts and floods in different regions.
    4. Wildfire Risk: Elevated probability of large-scale forest fires in drought-prone regions.

    Why Does the Impact of El Niño Differ Across Regions?

    Not Every El Niño Produces the Same Outcomes

    1. Climate Variability: Every El Niño develops differently in terms of intensity, timing and ocean-atmosphere interaction.
    2. NOAA Observation: Each El Niño leaves a unique climatic imprint on global weather systems.
    3. Regional Factors: Local ocean temperatures, atmospheric circulation and other climate oscillations influence outcomes.

    Importance of Forecasting

    1. Advanced Monitoring: Improved ocean observation systems enhance prediction capabilities.
    2. Early Warning Systems: Better forecasting enables governments to prepare for disasters and agricultural losses.
    3. Climate Preparedness: Supports adaptation planning and resource allocation.

    How Could Super El Niño Reshape Global Weather Patterns?

    North America

    1. Atlantic Hurricane Suppression: Reduced hurricane activity in the Atlantic Ocean.
    2. Pacific Hurricane Intensification: Increased cyclone activity over the Pacific.
    3. US Winter Impact: Southern United States may experience wetter conditions and flooding.
    4. Pacific Northwest: Warmer and drier weather expected.

    South America

    1. Flood Risk: Northern Peru and southern Ecuador face heightened flooding threats.
    2. Heavy Rainfall: Western South America may experience excessive precipitation.
    3. Temperature Rise: Greater likelihood of unusually warm summers.

    East and Northeast Africa

    1. Weather Whiplash: Rapid shifts between drought and extreme rainfall.
    2. Flood Hazards: Increased flood risk in vulnerable regions.
    3. Agricultural Stress: High uncertainty for rain-fed agriculture.

    India

    1. Monsoon Deficit: Higher probability of below-normal rainfall.
    2. Heatwaves: Greater frequency and intensity.
    3. Agricultural Losses: Increased stress on kharif crops and water resources.

    Indonesia and Vietnam

    1. Drought Risk: Rainfall shortages may affect major rice-producing regions.
    2. Food Security Concerns: Potential reduction in agricultural output.

    Australia

    1. Heatwaves: Higher temperature anomalies.
    2. Wildfires: Elevated bushfire risk.
    3. Drought Conditions: Reduced precipitation in several regions.

    Why Does El Niño Affect India’s Southwest Monsoon?

    1. Walker Circulation Shift: Alters atmospheric circulation responsible for moisture transport.
    2. Reduced Moisture Transport: Weakens monsoon winds reaching the Indian subcontinent.
    3. Rainfall Deficiency: Leads to below-normal precipitation across large parts of India.
    4. Temperature Rise: Reduced cloud cover increases surface temperatures.

    IMD Forecast

    1. Seasonal Deficit: Rainfall expected to be 10% below normal.
    2. Spatial Distribution: Most regions likely to receive below-normal rainfall.
    3. Exception: Northeastern India expected to receive relatively normal rainfall.

    How Do Rainfall Patterns Change During El Niño Years?

    Regional Variability

    1. Northeastern India: Often receives normal rainfall.
    2. Extreme Southern India: May receive near-normal rainfall.
    3. Rest of India: Usually experiences rainfall deficits.

    Temperature Effects

    1. Heat Intensification: Reduced rainfall contributes to rising temperatures.
    2. Extended Heat Conditions: Higher risk of heatwaves and moisture stress.

    What Role Does the Indian Ocean Dipole (IOD) Play?

    Indian Ocean Dipole (IOD)

    1. Definition: Difference in sea surface temperatures between western and eastern Indian Ocean.
    2. Phases: Positive, Neutral, Negative.

    Current Status

    1. Neutral Phase: Expected to remain neutral during the southwest monsoon.
    2. 2026 Outlook: Neutral conditions expected to continue for most of the year.

    Significance

    1. Monsoon Modulator: Positive IOD can sometimes offset El Niño-induced monsoon weakness.
    2. Current Concern: Neutral IOD may not provide compensatory support.

    What Oceanic Changes Are Being Observed Around India?

    Bay of Bengal Warming

    1. Temperature Increase: Significant positive sea surface temperature anomalies observed.
    2. Impact: Supports atmospheric instability and temperature rise.

    Arabian Sea Warming

    1. Above-Normal Temperatures: Positive SST anomalies recorded.
    2. Climate Consequence: Enhances extreme weather variability.

    Eastern Indian Ocean

    1. Widespread Warming: Above-normal SST conditions observed during May

    How Could Super El Niño Trigger a Global Food Security Crisis?

    Agricultural Disruptions

    1. Crop Vulnerability: Maize, rice and several staple crops are highly sensitive to drought conditions.
    2. Production Risks: Major agricultural regions may experience reduced productivity.
    3. Market Volatility: Supply shocks can increase global food prices.

    Countries at Risk

    1. India: Rainfed agriculture vulnerable to monsoon deficits.
    2. South Africa: Drought threatens maize production.
    3. Indonesia: Rice production risks increase.
    4. Vietnam: Potential impacts on rice exports.
    5. Brazil: Rainfall variability may affect agricultural output.

    Global Consequences

    1. Food Inflation: Rising prices of cereals and food commodities.
    2. Supply Chain Disruptions: Agricultural trade flows may be affected.
    3. Livelihood Risks: Farmers and vulnerable populations face income losses.

    Why Is El Niño a Concern for India’s Economy and Agriculture?

    1. Agriculture
      1. Crop Stress: Reduces soil moisture availability.
      2. Rainfed Farming: Increases vulnerability of kharif crops.
      3. Yield Losses: Impacts rice, pulses, oilseeds, and coarse cereals.
    2. Water Security
      1. Reservoir Recharge: Limits replenishment of water bodies.
      2. Groundwater Stress: Increases extraction pressures.
    3. Inflation
      1. Food Prices: Reduced agricultural output may trigger food inflation.
      2. Supply Constraints: Affect agricultural supply chains.
    4. Energy
      1. Power Demand: Rising temperatures increase cooling requirements.
      2. Hydropower: Lower reservoir levels affect generation capacity.

    What Lessons Can Be Drawn from the 2015-16 Super El Niño?

    India’s Experience

    1. Rainfall Deficit: India received only 86% of Long Period Average (LPA) rainfall.
    2. Agricultural Stress: Several states experienced drought-like conditions.
    3. Water Scarcity: Reservoir levels and groundwater recharge declined.

    Key Lesson

    1. ENSO Alone is Not Deterministic: Strong El Niño events do not always produce identical outcomes.
    2. Role of Other Drivers: Indian Ocean Dipole (IOD), Madden-Julian Oscillation (MJO), Eurasian snow cover and regional ocean temperatures also influence monsoon performance.

    Conclusion

    The emerging El Niño highlights the growing interaction between natural climate variability and global warming. With risks of weaker monsoons, heatwaves, food insecurity and extreme weather events, India must strengthen climate-resilient agriculture, early warning systems, water management and disaster preparedness to reduce vulnerability and build long-term resilience.

    Value Addition

    YearCharacteristicsGlobal Impact
    1982-83One of strongest recordedDroughts, floods, crop losses
    1997-98Extreme warmingMajor global weather disruptions
    2015-16Strongest of recent decadesGlobal temperature records broken
    2026-27*Potential Super El NiñoRisk of hottest year in recorded history

    Positive vs Negative IOD

    Positive IODNegative IOD
    Warmer western Indian OceanWarmer eastern Indian Ocean
    Supports Indian monsoonWeakens monsoon
    Can offset El Niño impactCan worsen El Niño impact

    PYQ Relevance

    [UPSC 2015] How far do you agree that the behavior of the Indian monsoon has been changing due to humanizing landscapes? Discuss.

    Linkage: The PYQ examines changing monsoon patterns and the factors affecting rainfall variability in India. The article discusses how the emerging Super El Niño could weaken the southwest monsoon, alter rainfall distribution, intensify heatwaves and interact with climate change to reshape India’s monsoon behaviour.

  • Aravalli range’s role in shielding Gangetic plains from Thar dust

    Why in the News?

    A massive dust storm recently affected Churu, Hanumangarh, Sri Ganganagar, Bikaner, Nagaur, Didwana-Kuchaman, Alwar and Sikar in Rajasthan, drawing attention to the critical role of the Aravalli Range in shielding the Indo-Gangetic Plains from Thar Desert dust. Scientists warn that degradation of the Aravallis due to mining, deforestation and land-use change is allowing more dust to reach Delhi, Punjab, Haryana and Uttar Pradesh, even during less intense storms.

    What are the features of the Aravallis Range?

    1. The Aravalli Range is one of the oldest surviving fold mountain systems on Earth. It serves as a vital ecological and climate-regulating spine across northwestern India.
    2. Location and Extent
      1. Length: The range stretches approximately 670 to 700 kilometres.
      2. Alignment: It runs in a distinct south-west to north-east direction.
      3. States Covered: The range begins near Delhi, passes through southern Haryana and Rajasthan, and terminates near Ahmedabad in Gujarat.
    3. Geological Significance
      1. Age: Formed during the Precambrian era (roughly 1.7 to 2.5 billion years ago), it predates the Himalayas by more than a billion years.
      2. Evolution: It was originally an immense mountain chain, potentially as tall as the modern Himalayas. Over eons, wind and water weathered it down into discontinuous, residual hills and ridges.
      3. Composition: The range consists of highly resistant metamorphic and igneous rocks, including quartzite, granite, schist, and gneiss
    4. Key Peaks and Drainage
      1. Highest Point: Guru Shikhar on the Mount Abu massif in Rajasthan, standing at 1,722 metres (5,650 feet).
      2. Major Rivers: The western slopes give rise to the Luni River (which drains into the Rann of Kutch) and the Sabarmati River. The eastern slopes feed the Banas River, a major tributary of the Chambal-Yamuna system.

    How do the Aravallis act as a natural shield against the Thar Desert dust?

    Dust Interception Mechanism

    1. Obstacle Dunes: Large sand deposits located on western slopes intercept dust-laden winds originating from the Thar Desert.
    2. Wind Velocity Reduction: Mountain slopes reduce wind speed, causing suspended dust particles to settle.
    3. Vegetation Barrier: Native vegetation acts as a natural scrubber, trapping dust and sand particles.
    4. Sediment Retention: Dunes and vegetation prevent long-distance transportation of desert sediments.
    5. Ecological Buffer: Protects densely populated Indo-Gangetic regions from excessive dust exposure.

    Scientific Evidence

    1. Field Observations: Obstacle dunes visibly demonstrate dust interception by the Aravallis.
    2. Vegetation Similarity: Dune vegetation resembles desert ecosystems, indicating long-term dust deposition processes.

    Why are dust storms becoming a growing concern in northern India?

    1. Increasing Dust Transport
      1. Pre-Monsoon Phenomenon: Dust storms commonly occur between April and June.
      2. Heat Conditions: Intense heating and dry atmospheric conditions facilitate dust mobilization.
      3. Wind Systems: South-westerly and westerly winds transport dust across northern India.
    2. Expanding Exposure
      1. IMD Climate Hazards Atlas: Identifies parts of northwest India within a high dust-storm frequency zone.
      2. Dust-Storm Frequency: Climatic normal ranges between 0.89 and 1.55 dust-storm days annually.
      3. Delhi Vulnerability: Long-term records place Delhi and adjacent districts within high exposure zones.
    3. Emerging Trend
      1. Lower Threshold Transport: Dust now reaches northern plains even during less intense storms.
      2. Wind Speed Impact: Dust transport increasingly observed at wind speeds of 35-40 kmph.
      3. Changing Pattern: Earlier, dust transport generally required stronger and more intense storm systems.

    How is degradation weakening the protective role of the Aravalli Range?

    1. Mining Activities
      1. Mineral Extraction: Mining of red silica, granite and other minerals has damaged hill ecosystems.
      2. Landscape Fragmentation: Mining operations create physical gaps that facilitate dust movement.
    2. Deforestation
      1. Vegetation Loss: Reduction in natural vegetation decreases dust-trapping capacity.
      2. Ecosystem Instability: Weakens soil retention and ecological resilience.
    3. Urbanisation and Construction
      1. Land Conversion: Expands built-up areas at the cost of ecological landscapes.
      2. Habitat Disruption: Alters natural terrain and ecological continuity.
    4. Land-Use Change
      1. Pastoral Activities: Intensive grazing pressures affect vegetation regeneration.
      2. Agricultural Expansion: Contributes to habitat modification and soil degradation.

    What is the current state of degradation in the Aravalli ecosystem?

    Forest Survey Findings

    1. Hill Loss: Assessment found that 31 out of 128 Aravalli hills in Rajasthan had disappeared due to anthropogenic pressures.
    2. Topographic Alteration: Significant reduction observed in hill systems between 200 and 600 metres above sea level.

    Affected Regions

    1. Naraina
    2. Kalwar
    3. Kotputli
    4. Jhalana
    5. Sariska

    These areas have witnessed substantial ecological disturbance.

    Government Assessment

    1. Aravalli Restoration Framework: Identified mining, deforestation, urbanisation, construction activities, land-use change, pastoral pressures and encroachments as major causes of degradation.

    What are the environmental and climatic consequences of Aravalli degradation?

    1. Air Quality Impacts
      1. Dust Intrusion: Increased transport of desert dust towards Delhi, Punjab, Haryana and Uttar Pradesh.
      2. Particulate Pollution: Worsens PM10 and PM2.5 concentrations.
      3. Public Health Risks: Raises respiratory and cardiovascular disease burden.
    2. Climate Impacts
      1. Rainfall Modification: Dust aerosols influence cloud formation and precipitation dynamics.
      2. Regional Climate Effects: Alter atmospheric circulation and radiation balance.
    3. Agricultural Impacts
      1. Soil Quality Changes: Dust deposition affects soil properties.
      2. Crop Stress: Reduced productivity under frequent dust exposure.
    4. Ecosystem Impacts
      1. Habitat Fragmentation: Reduces biodiversity connectivity.
      2. Desertification Risk: Facilitates eastward spread of arid conditions.

    Why are ecological gaps in the Aravallis a strategic environmental concern?

    1. Wildlife Institute Findings
      1. Gap Expansion: Twelve major gaps have been identified within the Aravalli system.
      2. Degradation Linkage: Expansion attributed to forest loss and inadequate ecological restoration.
    2. Dust Corridor Formation
      1. Wind Channels: Openings facilitate unhindered movement of dust particles.
      2. Reduced Interception: Weakens the range’s barrier function.
    3. Multi-State Implications
      1. Delhi: Air quality deterioration.
      2. Punjab and Haryana: Increased dust exposure.
      3. Uttar Pradesh: Greater environmental vulnerability.

    What policy interventions are required to restore the Aravalli ecosystem?

    1. Landscape Restoration
      1. Afforestation: Strengthens vegetative barriers across degraded stretches.
      2. Native Species Plantation: Enhances ecological adaptation and dust interception.
    2. Mining Regulation
      1. Compliance Mechanisms: Ensures strict implementation of environmental clearances.
      2. Illegal Mining Control: Prevents further hill degradation.
    3. Ecosystem-Based Management
      1. Watershed Restoration: Improves ecological stability.
      2. Soil Conservation: Reduces erosion and dust generation.
    4. Institutional Coordination
      1. Inter-State Cooperation: Facilitates coordinated conservation across Rajasthan, Haryana, Delhi and Gujarat.
      2. Integrated Monitoring: Strengthens environmental surveillance using remote sensing and GIS.
    5. Climate Adaptation
      1. Nature-Based Solutions: Enhances resilience against desertification and dust storms.
      2. Green Buffer Development: Supports long-term air quality management.

    Conclusion

    The Aravalli Range is not merely a geological feature but a critical ecological barrier that protects northern India from desert dust, air pollution and land degradation. Its continuing degradation due to mining, deforestation and unplanned development threatens the environmental security of Rajasthan, Delhi and the wider Indo-Gangetic Plains, making landscape restoration and sustainable management an urgent policy priority.

    PYQ Relevance

    [UPSC 2020] The process of desertification does not have climatic boundaries. Justify with examples

    Linkage: The PYQ tests understanding of desertification, land degradation and the wider ecological impacts of environmental change beyond arid regions. The article shows how degradation of the Aravalli Range is enabling Thar Desert dust to spread into Delhi and the Indo-Gangetic Plains, illustrating that the effects of desertification can extend far beyond desert areas.

  • Big Island (Hawaii)

    Why in the news?

    A magnitude 6.0 earthquake struck near Honaunau-Napoopoo on the Big Island.

    About the Big Island

    • The largest island in the Hawaiian archipelago
    • Part of Hawaii in the Pacific Ocean
    • Area: ~10,432 km²
    • Formed through volcanic activity

    Five Major Volcanoes

    • Kohala
    • Hualālai
    • Mauna Kea
    • Mauna Loa
    • Kīlauea

    Important Volcanoes

    Mauna Loa

    • One of the world’s largest volcanoes
    • Shield volcano
    • Greatest mass of any mountain on Earth

    Kīlauea

    • Among the world’s most active volcanoes
    • Frequently erupting since 1983

    Shield Volcano

    • A volcano with broad, gentle slopes formed by fluid lava flows. Examples: Mauna Loa and Kīlauea

    Mauna Kea

    • The highest point in Hawaii above sea level
    • Hosts major astronomical observatories

    Hawaiʻi Volcanoes National Park

    • UNESCO World Heritage Site
    • Protects Kīlauea and Mauna Loa volcanoes

    Why are Earthquakes Common in Hawaii?

    Due to:

    • Volcanic activity
    • Movement of tectonic plates
    • Hotspot volcanism

    Hotspot Volcanism

    • A hotspot is a place where hot magma rises from Earth’s mantle. As the Pacific Plate moves over it, volcanic islands form.

    [2024] Consider the following:
    1. Pyroclastic debris
    2. Ash and dust
    3. Nitrogen compounds
    4. Sulphur compounds
    How many of the above are products of volcanic eruptions?

    [A] Only one

    [B] Only two

    [C] Only three

    [D] All four

  • AMOC Collapse and Its Impact on India 

    Why in the News

    Scientists have warned that the Atlantic Meridional Overturning Circulation (AMOC), a major Atlantic Ocean current system, could weaken drastically by 2100 due to climate change, potentially affecting global climate and the Indian monsoon.

    What is AMOC (Atlantic Meridional Overturning Circulation)?

    • A large system of ocean currents in the Atlantic Ocean often described as a global ocean conveyor belt

    How AMOC Works

    • Warm, salty surface water flows northward from the tropics
    • Near the Arctic, water cools and becomes denser
    • Dense water sinks deep into the ocean
    • Cold deep water then flows southward

    Importance of AMOC

    • Maintains relatively mild climate in Europe
    • Influences:
      • Rainfall patterns
      • Monsoons
      • Global temperature distribution
      • Marine ecosystems

    Connection with El Niño

    • El Niño
      • Periodic warming of Pacific Ocean waters
      • Influences global weather patterns
    • A weaker AMOC may: Make El Niño events more extreme and unpredictable
    [2020] With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct? 
    1.OMT is measured up to a depth of 26ºC isotherm which is 129 meters in the south-western Indian Ocean during January-March. 
    2.OMT collected during January-March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean. 
    Select the correct answer using the code given below: 
    a) 1 only b) 2 only c) Both 1 and 2 d) Neither 1 nor 2
  • Mayon Volcano 

    Why in the News

    The Mayon Volcano recently erupted, leading to the evacuation of thousands of people in affected areas of the Philippines.

    About Mayon Volcano

    • Type: Active stratovolcano (composite volcano)
    • Location: Albay province, Luzon Island
    • Height: 2,462 metres
    • Known as: “World’s most perfect volcanic cone” due to its symmetry

    Geographical Setting

    • Part of the Pacific Ring of Fire
    • Located near the Philippine Trench
    • Formed at a convergent plate boundary
      • Philippine Sea Plate subducting beneath the Philippine Mobile Belt

    What is a Stratovolcano

    • Tall, steep cone shaped volcano
    • Built from alternating layers of:
      • Lava
      • Pyroclastic material
    • Found mainly in subduction zones
    • Magma type:
      • Andesite and dacite (viscous lava)
    • Leads to explosive eruptions
    [2024] Consider the following: 
    1. Pyroclastic debris 
    2. Ash and dust 
    3. Nitrogen compounds 
    4. Sulphur compounds 
    How many of the above are products of volcanic eruptions? 
    [A] Only one [B] Only two [C] Only three [D] All four
  • Andaman Sea  

    Why in the News?

    • A boat carrying Rohingya refugees capsized in the Andaman Sea, highlighting its strategic and humanitarian importance.

    About the Andaman Sea

    What it is

    • A marginal sea of the northeastern Indian Ocean
    • Acts as a maritime link between:
      • South Asia
      • Southeast Asia

    Location

    • Lies between:
      • 4°N to 20°N latitude
      • 92°E to 100°E longitude

    Connected Water Bodies

    • West: Bay of Bengal
    • East: South China Sea (via Strait of Malacca)

    Boundaries

    • North: Irrawaddy delta (Myanmar)
    • East: Myanmar, Thailand, Malaysia
    • South: Indonesia (Sumatra)
    • West: Andaman & Nicobar Islands (India)

    Origin of Name

    • Derived from “Handuman” (Malay form of Hanuman)
    • Linked to ancient maritime trade and cultural exchanges
    [2020] Consider the following pairs: River – Flows into 
    1. Mekong — Andaman Sea 
    2. Thames — Irish Sea 
    3. Volga — Caspian Sea 
    4. Zambezi — Indian Ocean 
    Which of the pairs given above is/are correctly matched? 
    a) 1 and 2 only b) 3 only c) 3 and 4 only d) 1, 2 and 4 only
  • Satellite data show India’s major deltas sinking

    Why in the News

    A global study published in Nature on 14 January reports widespread land subsidence across India’s major river deltas, driven largely by human activities and observed using Sentinel 1 satellite data.

    Study at a Glance

    • Data source Interferometric Synthetic Aperture Radar from ESA Sentinel 1
    • Period 2014 to 2023
    • Coverage 40 major global deltas including 6 Indian deltas
    • Spatial resolution 75 metres
    • Population relevance Deltas support over 340 million people globally

    Indian Deltas Confirmed to be Sinking

    • Ganges Brahmaputra Delta, Brahmani Delta, Mahanadi Delta, Godavari Delta, Cauvery Delta and Kabani Delta.
    • More than 90 percent area affected in Ganges Brahmaputra, Brahmani and Mahanadi deltas.

    Key Quantitative Findings

    • Brahmani delta: 77 percent area sinking at more than 5 mm per year
    • Mahanadi delta: 69 percent area sinking at more than 5 mm per year
    • In Ganges, Brahmani, Mahanadi, Godavari and Kabani,
      Subsidence rate exceeds regional sea level rise
    • Godavari delta: Even 95th percentile subsidence exceeds projected global sea level rise under worst climate scenario
    • Kolkata: Subsidence equals or exceeds delta average due to urban load and resource extraction

    Major Human Drivers Identified

    • Unsustainable groundwater extraction: Ganges Brahmaputra and Cauvery deltas
    • Rapid urbanisation: Brahmani delta
    • Reduced sediment flux: Mahanadi and Kabani deltas
    • Population pressure: Intensifies compaction and land lowering
    [2018] Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? 

    1. Decreased salinity in the river 

    2. Pollution of groundwater 

    3. Lowering of the water-table 

    Select the correct answer using the code given below: 

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

  • Show Cause Notice on Bargi Dam 

    Why in the News?

    The National Dam Safety Authority issued a show cause notice to the Narmada Valley Development Authority over serious safety lapses at Bargi Dam.

    About Bargi Dam

    • A major multipurpose dam
    • Used for irrigation, drinking water supply, and hydroelectric power generation
    • Jabalpur district, Madhya Pradesh
    • Constructed on the Narmada River

    Historical Background

    • Built under the Narmada Valley Development Project
    • First completed major dam among the planned series on the Narmada in Madhya Pradesh
    • Became the foundation project for the state’s Narmada basin development strategy

    Key Features

    • 21 spillway gates: Regulate flood discharge and reservoir levels during heavy rainfall
    • Bargi Diversion Project: Canal network supplying irrigation to drought prone regions
    • Rani Avantibai Lodhi Sagar Project: Large scale storage and distribution system for irrigation and water supply
    • Large reservoir supporting: Drinking water, Hydropower, Fisheries and Tourism and recreation

    Significance

    • Provides drinking water to Jabalpur and nearby districts
    • Supports agriculture through assured irrigation
    • Contributes to electricity generation
    • Boosts regional development and eco tourism

    Institutional Context

    National Dam Safety Authority

    • Apex body under the Dam Safety Act 2021
    • Responsible for surveillance, inspection, and safety compliance of specified dams

    Narmada Valley Development Authority

    • Implements and manages projects under the Narmada basin
    • Responsible for operation and maintenance of dams like Bargi

    Prelims Pointers

    • Bargi Dam is on the Narmada River
    • Located in Madhya Pradesh
    • Part of the Narmada Valley Development Project
    • NDSA acts under the Dam Safety Act 2021
    • Spillway gates are crucial for flood control
    [2016] The Narmada river flows to the west, while most other large peninsular rivers flow to the east. Why? 

    1. It occupies a linear rift valley

    2. It flows between the Vindhyas and the Satpuras

    3. The land slopes to the west from Central India

    Select the correct answer using the codes given below

    (a) 1 only (b) 2 and 3 (c) 1 and 3 (d) None