Quality of Public Expenditure Index

For Prelims: Reserve Bank of India, Quality of Public Expenditure Index, Global Financial Crisis, Fiscal Responsibility and Budget Management (FRBM) Act, 2003, Goods and Services Tax (GST), Zero-Based Budgeting. 

For Mains: Public Expenditure, Quality of Public Expenditure, Fiscal Discipline. 

Source: IE 

Why in News?  

The Reserve Bank of India (RBI) has developed the Quality of Public Expenditure (QPE) Index to assess how efficiently the Centre and state governments allocate public funds.  

What is the Quality of Public Expenditure Index?

• About: QPE Index is a framework that  assesses the efficiency of government spending.  
  • Rather than focusing solely on the total expenditure, the index analyzes the composition of spending and its impact on long-term economic growth and development. 
• Key Components: The index is based on five major indicators:

Indicator	What It Measures	Significance
Capital Outlay to GDP Ratio	Share of Gross Domestic Product (GDP) allocated to infrastructure (roads, railways, power, etc.).	A higher ratio indicates better expenditure quality.
Revenue Expenditure to Capital Outlay Ratio	Comparison of spending on salaries, pensions, and subsidies vs. infrastructure and asset creation.	A lower ratio indicates more funds allocated to productive investments.
Development Expenditure to GDP Ratio	Spending on education, healthcare, R&D, and public infrastructure.	A higher ratio indicates improved economic productivity.
Development Expenditure as Share of Total Government Expenditure	Proportion of the total budget dedicated to development sectors.	Higher share indicates higher spending quality.
Interest Payments to Total Expenditure Ratio	The financial burden of past borrowings.	A lower ratio indicates better fiscal health and more funds for development.

• Key Findings: The RBI’s QPE Index has categorised India’s public expenditure trajectory since 1991 into six distinct phases. 
  • 1991–1997: Early liberalization saw slight improvement in Centre’s expenditure quality, but states struggled amid fiscal pressures and declining public investment. 
  • 1997–2003: Expenditure quality declined due to salary hikes (Fifth Pay Commission), rising interest payments, and revenue-heavy spending. 
  • 2003–2008: Fiscal Responsibility and Budget Management (FRBM) Act, 2003 enforced in 2004, improved fiscal discipline.  
    • States benefited from higher tax devolution, but the 2008 Global Financial Crisis (GFC) halted progress. 
  • 2008–2013: The Centre’s stimulus spending initially improved quality but later caused fiscal imbalances. 
  • 2013–2019: States improved with higher development spending and 14th Finance Commission funds, while the Centre faced challenges as Goods and Services Tax (GST) revenue sharing initially benefited states more. 
  • 2019–2025: Fiscal stimulus measures during Covid-19 led to a temporary decline in expenditure quality. 
    • Post-pandemic recovery, driven by higher capital expenditure, helped improve spending efficiency. 
    • In 2024-25, India's QPE is at its highest level since the 1991 economic liberalization, reflecting improved fiscal management and spending efficiency. 

What is Public Expenditure? 

• About: Public expenditure (PE) refers to the spending by the government to fulfill collective needs such as education, healthcare, infrastructure, and welfare. 
• Objective: PE ensures efficient resource allocation, promotes income redistribution, and maintains economic stability by managing inflation and employment.  
  • It also drives development through investments in infrastructure, technology, and welfare, fostering inclusive growth. 
• Classification:  
  • Revenue Expenditure: Routine expenses like salaries, pensions, and interest payments. 
  • Capital Expenditure: Investments in long-term assets. A higher share of capital expenditure (Capex) improves the quality of public spending, leading to long-term economic growth. 
• Recent PE Trends: According to the Economic Survey 2024-25, government Capex increased 8.2% YoY, while state revenue expenditure grew 12% Year-over-year (YoY).  
  • The Union Budget 2025-26 has allocated Rs 11.21 lakh crore for capital expenditure (3.1% of GDP) in FY 2025-26. 
• Challenges: Excessive spending on salaries, pensions, and subsidies (revenue expenditure) and welfare (like free electricity) can reduce financial sustainability. 
  • Excessive PE leads to fiscal deficits and debt burdens, reducing funds for development.  
  • Higher budget deficits strain public finances, limiting the government's ability to invest in development.  
  • High Revenue Expenditure can weaken investor confidence, affecting overall economic stability. 

Way Forward 

• Prioritizing Zero-Based Budgeting (ZBB) and Performance-Based Budgeting ensures efficient and accountable fund allocation.  
  • Focus on high-impact sectors like health, education, and infrastructure that can drive economic growth and improve social well-being.   
  • Increase devolution of funds to states and local governments for need-based allocation, while ensuring fiscal prudence. 
• To reduce deficit financing, promoting self-sustaining projects and attracting domestic and foreign investment is essential for long-term fiscal stability. 
• Expand Direct Benefit Transfers (DBTs) through financial inclusion via the Jan Dhan-Aadhar-Mobile (JAM) Trinity to reduce leakages and corruption in revenue expenditure. 

Drishti Mains Question: 

Discuss the significance of the Quality of Public Expenditure Index in assessing fiscal efficiency. How can it help improve government spending in India?

UPSC Civil Services Examination, Previous Year Question (PYQ) 

Prelims

Q. Which of the following is/are included in the capital budget of the Government of India? (2016)

1. Expenditure on acquisition of assets like roads, buildings, machinery, etc. 
2. Loans received from foreign governments 
3. Loans and advances granted to the States and Union Territories 

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 

Ans: (d)

Q. There has been a persistent deficit budget year after year. Which action/actions of the following can be taken by the Government to reduce the deficit? (2016)

1. Reducing revenue expenditure 
2. Introducing new welfare schemes 
3. Rationalizing subsidies 
4. Reducing import duty 

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, 3 and 4 

Ans: (c)

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Mains:

Q1. Distinguish between Capital Budget and Revenue Budget. Explain the components of both these Budgets. (2021) 

Q2. The public expenditure management is a challenge to the Government of India in the context of budget-making during the post-liberalization period. (2019)

Waste Segregation and Waste-to-Energy Plant

For Prelims: Solid Waste Management Rules, 2016, Central Pollution Control Board (CPCB), Waste-to-Energy Plant, Domestic Hazardous Waste, Biogas, BioCNG, Syngas, Refuse-Derived Fuel (RDF), Methane, Circular Economy, Greenhouse Gas (GHG) 

For Mains: Significance of waste segregation at source and waste-to-energy plants in environmental conservation.  

Source: TH 

Why in News? 

The Supreme Court (SC) emphasised the importance of waste segregation at source and questioned National Capital Region (NCR) states on the implementation of segregation of waste at source as per the Solid Waste Management Rules (SWM Rules, 2016). 

• The SC directed the Central Pollution Control Board (CPCB) to report on the public health and environmental impact of waste-to-energy plants. 

Note: NCR comprises Delhi and certain districts of Haryana, Uttar Pradesh and Rajasthan. 

Click Here to Read: What are the Solid Waste Management Rules 2016? 

What is Waste Segregation at Source? 

• About Solid Waste: It refers to any type of garbage, trash, refuse or discarded material generated from households, industries, businesses, and other human activities. 
  • They require proper management to prevent environmental and health hazards. 
• Waste Segregation at Source: It refers to the process of identifying, classifying, dividing, and sorting waste at the point of generation to facilitate proper disposal, recycling, and management.  
  • It categorizes waste based on its biological, physical, and chemical properties. 
• Provisions in SWM Rules, 2016: SWM Rules, 2016 categories waste into 3 categories i.e., biodegradables, non-biodegradables, and domestic hazardous waste. 
  • Biodegradables: Organic waste that can be degraded by micro-organisms into simpler stable compounds like food scraps, soiled wrappers, paper etc. Non-biodegradables: Recyclable/non-recyclable items like plastic, glass, metal, etc. 
  • Domestic Hazardous waste: Diapers, napkins, mosquito repellants, cleaning agents etc. 

• Significance: 
  • Prevents Contamination: Keeps hazardous and non-hazardous waste separate, reducing pollution. 
  • Reduces Landfill Waste: Sends only non-recyclable waste to landfills. 
  • Enhances Recycling: Improves resource recovery and reduces raw material use. Enables composting, recycling, and waste treatment. 
  • Minimizes Health Risks: Prevents disease from medical and hazardous waste. 
  • Promotes Responsibility: Encourages community participation in waste management. 

Solid Waste Generation  

• As per Annual Report of CPCB for the year 2021-22, the average quantity of solid waste generated in India is 1,70,338 tonnes per day (TPD), of which 91,512 TPD is treated. 
• Delhi generates over 11,000 metric tonnes of solid waste daily, while waste treatment plants can process only 8,073 metric tonnes. 
• In FY 2014-15, India processed only 18% of its total waste, which rose significantly to over 78% in FY 2024. 

What is a Waste-to-Energy Plant? 

• About: Waste-to-energy (WtE) plants convert municipal solid waste (MSW) into energy in the form of electricity, heat, or fuel through various technologies like pyrolysis, anaerobic digestion etc. 
  • It also generates Biogas/ BioCNG/Syngas from urban, industrial and agricultural wastes/residues. 
• Related Provisions in SWM Rules, 2016:  
  • Utilization of Non-Recyclable Waste: Waste with a calorific value of 1500 Kcal/kg or more must be used for energy generation and cannot be disposed of in landfills. 
    • High-calorific waste should be co-processed in cement or thermal power plants. 
  • Mandatory Use of RDF: Industrial units using fuel and located within 100 km of a solid waste-based Refuse-Derived Fuel (RDF) plant must replace at least 5% of their fuel with RDF. 
    • RDF is made from municipal and industrial waste by removing non-combustibles, leaving plastics, paper, textiles, and biomass. 
• Methods of WtE Conversion: 
  • Incineration: Waste is burned at ultra-high temperatures, producing heat that generates steam to spin turbines and create electricity.  
  • Gasification: Biomass is processed at high temperatures without combustion to produce syngas, which serves as fuel for electricity generation or industrial use. 
  • Anaerobic Digestion: Microorganisms break down organic waste in an oxygen-free environment, producing biogas rich in methane. 
  • Fermentation and Distillation: Organic biomass is fermented and distilled to produce ethanol, an alternative fuel for engines. 
  • Pyrolysis: A thermo-chemical process that converts waste into clean liquid fuels (bio-oil, syngas, and char) under high temperatures in the absence of oxygen. 
  • Landfill Gas Recovery: Methane and other gases released from landfills are captured through wells using blowers and vacuums, then treated for energy production. 
• Significance: 
  • Utilization of Waste: Converts waste into heat and electricity, reducing the need for fossil fuels. 
  • Reduction in Landfilling: Reduces landfill waste and related environmental risks like emissions, land use, and groundwater contamination. 
  • Resource Recovery: Enables metal recovery after incineration and retains valuable materials in the circular economy. 
  • Reduction in GHG Emissions: Landfills produce methane emissions, a potent Greenhouse Gas (GHG) while waste-to-energy reduces them by diverting waste. 

Draft SWM Rules, 2024 

• The Draft SWM Rules, 2024 were issued by the Central Government in exercise of the powers conferred by the Environment (Protection) Act, 1986. 
• Key Provisions: 
  • Provision for Fines: 'Safai Karamcharis' (Sanitation Workers) will be authorized to levy fines and penalties on unsegregated waste and refuse collection if segregation rules are ignored. 
  • Segregation of Solid Waste: Segregate and store the waste generated by them in four separate streams at source namely wet waste, dry waste, sanitary waste and special care waste. 
  • Agricultural Waste Management: Gram Panchayats must prevent open burning of agricultural waste, impose penalties for stubble burning, and facilitate agri-residue collection and storage for use. 

Conclusion 

Effective solid waste management through source segregation and waste-to-energy solutions is crucial for sustainable urban development. While SWM Rules, 2016 provide a framework, challenges in enforcement, integration of the informal sector, and environmental concerns over waste-to-energy plants highlight the need for stricter monitoring and decentralized waste processing. 

Drishti Mains Question:

Analyze the role of waste-to-energy plants in India’s waste management strategy.

UPSC Civil Services Examination, Previous Year Question (PYQ) 

Prelims

Q. As per the Solid Waste Management Rules, 2016 in India, which one of the following statements is correct? (2019)

(a) Waste generator has to segregate waste into five categories. 

(b) The Rules are applicable to notified urban local bodies, notified towns and all industrial townships only. 

(c) The Rules provide for exact and elaborate criteria for the identification of sites for landfills and waste processing facilities. 

(d) It is mandatory on the part of waste generator that the waste generated in one district cannot be moved to another district. 

Ans: (c)

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Mains

Q. What are the impediments in disposing of the huge quantities of discarded solid waste which are continuously being generated? How do we safely remove the toxic wastes that have been accumulating in our habitable environment? (2018)

Q. “To ensure effective implementation of policies addressing the water, sanitation and hygiene needs the identification of the beneficiary segments is to be synchronised with anticipated outcomes.” Examine the statement in the context of the WASH scheme. (2017)

Self-Testing of HIV

Source: IE 

Why in News?  

A study by the Indian Council of Medical Research-National Institute of Translational Virology and AIDS Research (ICMR-NITVAR) and Mizoram University has highlighted the success of Human Immunodeficiency Virus (HIV) self-testing in Mizoram. 

What are the Key Findings of the Study? 

• HIV Self-Testing: The study examined HIV self-testing implementation in Mizoram, which has India's highest HIV prevalence (2.73%), 13 times the national average. 
  • The epidemic in the state is largely driven by injecting drug use and commercial sex work. 
    • Lack of early testing and stigma prevents many from accessing timely treatment. 
  • HIV self-testing allows individuals to collect their own blood or saliva samples and interpret the results using a test kit. 
• Stigma-Free & Private: The study found self-testing to be a convenient, confidential, and more effective way for high-risk groups to know their HIV status than traditional campaigns, with potential for replication in other states. 

Note: The World Health Organization (WHO) endorsed self-testing in 2016, and 41 countries have since adopted it. India has not yet introduced formal guidelines for HIV self-testing. 

What are the Key Facts About Human Immunodeficiency Virus? 

• About: HIV is a virus that attacks the immune system by targeting CD4 cells (white blood cells). If untreated, it can lead to AIDS (Acquired Immunodeficiency Syndrome) and making the body prone to infections and cancers. 
• Transmission: HIV spreads through direct contact of infected bodily fluids like blood, semen, breast milk, vaginal fluids, and via unprotected sex, tattooing, and shared needles but not through casual contact. 
• Symptoms: Early stage (fever, rash), Later stage (swollen lymph nodes, weight loss, diarrhea), and Severe stage (tuberculosis, meningitis, cancers (e.g. lymphoma)). 
• Risk Factors: Multiple sexual partners or having sexually transmitted infections (STIs), Unsafe blood transfusions. 
• Diagnosis: Rapid diagnostic tests for same-day results, Self-testing kits, and Confirmatory virological tests. 
• Prevention: Regular HIV testing, STI screening, safe blood transfusions, and using sterilized needles for tattoos are essential for prevention. 
• Treatment: No cure for HIV, Antiretroviral Therapy (ART) helps control the virus. ART must be taken daily for life to maintain health. 
• Advanced HIV Disease (AHD): WHO defines AHD as CD4 <200 cells/mm³. People with AHD are at high risk of death, even after starting ART. 
• Global Response: End HIV epidemic by 2030 (UN Sustainable Development Goal 3.3). 
• India’s Progress: India HIV Estimations 2023 reports 2.5 million people living with HIV, with 0.2% adult prevalence. New infections dropped 44% since 2010, surpassing the global 39% decline. 
  • The National AIDS Control Programme (NACP), launched in 1992, remains key in India's fight against HIV/AIDS.

UPSC Civil Services Examination Previous Year Question (PYQ) 

Q. Which of the following diseases can be transmitted from one person to another through tattooing? (2013)

1. Chikungunya 
2. Hepatitis B 
3. HIV-AIDS 

Select the correct answer using the codes given below: 

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

Ans: (b)

Q. Which one of the following statements is not correct? (2019) 

(a) Hepatitis B virus is transmitted much like HIV.  

(b) Hepatitis B unlike Hepatitis C, does not have a vaccine.  

(c) Globally, the number of people infected with Hepatitis B and C viruses arc several times more than those infected with HIV.  

(d) Some of those infected with Hepatitis B and C viruses do not show the symptoms for many years.  

Ans: (b)

Q. With regard to the transmission of the Human Immunodeficiency Virus, which one of the following statements is not correct? (2010) 

(a) The chances of transmission from female to male are twice as likely as from male to female

(b) The chances of transmission are more if a person suffers from other sexually transmitted infections  

(c) An infected mother can transmit the infection to her baby during pregnancy, at childbirth and by breast feeding  

(d) The risk of contracting infection from transfusion of infected blood is much higher than an exposure to contaminated needle  

Ans: (a)

Q. Consider the following statements: (2010)

1. Hepatitis B is several times more infectious than HIV/AIDS 
2. Hepatitis B can cause liver cancer 

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  

Ans: (c)

Cleaner Methods of Energy Generation

Source: TH 

Why in News? 

India must adopt cleaner methods of energy generation, as coal-based electricity generation causes significant air pollution, harming crops, humans and animals. 

• Cleaner methods of energy generation use renewable, and low-carbon technologies to produce electricity with minimal pollution and environmental impact.

Note: Nitrogen dioxide and ozone from coal plants reduce wheat and rice yields by over 10% in some parts of India.  

• It negated six years of agricultural growth despite better crops, irrigation, and mechanization. 

What are Available Cleaner Methods of Energy Generation? 

• Osmotic Power: It generates electricity using osmotic pressure differences between freshwater and seawater. 
  • India has a vast coastline of 7,500 km, where rivers drain into the sea, and this technology can effectively generate electricity.  
  • Osmotic power (salinity gradient energy) generates electricity using the salt concentration difference between freshwater and seawater through osmotic pressure. 
• Nuclear Power: Nuclear power plants use nuclear fission to heat water, create steam, and spin turbines to generate electricity.  
  • India’s Nuclear power generation capacity stands at 8,180 MW in 2024 and is projected to triple to 22,480 MW by 2031-32. 
  • The government has set an ambitious target of 100 GW nuclear power capacity by 2047. 
• Biomass Energy: Organic materials (wood, crop waste, algae) are burned or converted into biofuels to produce electricity. 
  • India produces 450-500 million tonnes of biomass annually, supplying 32% of the country's primary energy. 
• Hydrogen Fuel Cells: They convert hydrogen into electricity through electrochemical reactions.  
  • They are used in vehicles and backup power systems, emitting only water vapor as a byproduct. 
• Waste-to-Energy (WTE): It converts municipal solid waste (MSW) and other waste materials into electricity, heat, or fuel through various technologies like 
  • Incineration: Waste is burned at high temperatures to produce steam, which drives a turbine to generate electricity. 
  • Gasification: Converts waste into syngas (a mixture of CO, H₂, and CH₄), a raw material for fuel. 
  • Pyrolysis: Organic waste is decomposed at high temperatures without oxygen, producing bio-oil, syngas, and biochar as usable fuels. 
• Wind Energy: It involves the use of wind power by placing windmills to generate electricity. 
  • India, the world's 4th largest wind power producer, generates 50 Gigawatts (GW) of electricity across nine windy states. 
• Solar Energy: It involves setting up solar panels on houses, buildings or large-scale solar farms that absorb sunlight and convert light into electricity. 
  • India is the world's 3rd largest solar power generator after China (1st) and USA (2nd). 
• Hydropower: It involves blocking part of a river by a dam and then water is released to generate electric power.  
  • The top five dams across India together generate as much as 50 GW of hydroelectric energy.  

UPSC Civil Services Examination Previous Year Question (PYQ)  

Prelims

Q. Which of the following are the reasons/factors for exposure to benzene pollution? (2020) 

1. Automobile exhaust
2. Tobacco smoke
3. Wood burning
4. Using varnished wooden furniture
5. Using products made of polyurethane

Select the correct answer using the code given below: 

(a) 1, 2 and 3 only  

(b) 2 and 4 only 

(c) 1, 3 and 4 only  

(d) 1, 2, 3, 4 and 5 

Ans: (a)

Mains

Q. In the context of solving pollution problems, what is/are the advantage/advantages of bioremediation technique? (2017) 

1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature.
2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms. 
3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation.

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 

Ans: (c)

Article 101(4)

Source: IE 

An independent Member of Parliament (MP), has approached the High Court over concerns regarding the potential loss of his Lok Sabha seat due to prolonged absence. 

Article 101(4): 

• Article 101 of the Constitution of India deals with the vacation of seats, disqualifications, and dual membership in Parliament. 
• As per Article 101(4) of the Constitution, if an MP remains absent from all meetings of the House for 60 days without permission, the House may declare their seat vacant.  
  • However, this period excludes days when the House is prorogued or adjourned for more than 4 consecutive days. 
  • This provision is intended to ensure that MPs actively participate in legislative proceedings.  
• A seat is vacated only when the House formally declares it vacant through a vote, not automatically. 
  • Barjinder Singh Hamdard, a Rajya Sabha MP, was disqualified in 2000 under Article 101(4) for sustained absence. 
• Procedure for Seeking Leave: 
  • MPs must request leave from the Committee on Members’ Absence, which reviews and reports to the House. The House then votes on approval or rejection. 
  • Leave is granted for up to 59 days at a time; MPs must submit a fresh request for extended absences. 

Read More: Major Constitutional Amendment: Part 1 

White Rhinos

Source: PhysOrg 

The northern white rhino is functionally extinct, with only 2 females remaining. However, In-vitro fertilization (IVF) advancements have raised hope, with 36 embryos ready for implantation to help save the subspecies. 

• IVF: IVF is a fertility treatment where an egg is fertilized outside the body and the embryo is implanted into the female’s uterus. 

White Rhino: 

• About: 
  • White rhinos are the 2nd largest land mammal after the elephant.  
  • They are also called square-lipped rhinoceroses due to their broad upper lip, and are not actually white. 
• Subspecies & IUCN Status: 
  • Northern White Rhino (Ceratotherium simum cottoni): Critically Endangered 
  • Southern White Rhino (Ceratotherium simum simum): Near Threatened 

• Habitat: 
  • Southern White Rhinos: South Africa, Namibia, Zimbabwe, and Kenya.  
  • Northern white Rhinos:  Now survive only in captivity in Kenya. 
• Social Behavior: They are semi-social and territorial, with males defending their territories (mark their territory with dung) and females roaming larger areas. 
  • Southern White Rhinos are more social, forming larger herds, while Northern White Rhinos have smaller groups. 
• Diet: Purely herbivorous, feeding on short grasses. 
• Threats: Poaching, Habitat loss, Low genetic diversity (especially in northern white rhinos), and climate change, which alters their habitat and water sources. 

Read More: State of the Rhino 2023 

Perovskite LEDs (PeLEDs)

Source: PIB 

India’s researchers developed a method to reduce anion migration in perovskite nanocrystals that can enable next-gen lighting and improve energy efficiency as lighting consumes nearly 20% of global electricity. 

• Anion migration in perovskite nanocrystals causes color instability and limits their use in lighting. 
• Perovskite LEDs (PeLEDs), made from perovskite nanocrystals, combine the advantages of Organic LEDs (OLEDs) & Quantum Dot LEDs (QLEDs), making them promising for next-generation lighting. 
  • PeLEDs combine the best features of OLEDs (flexibility, lightweight) and QLEDs (high color purity) while offering superior efficiency and cost-effectiveness. 

Evolution of Lighting Technologies: 

• Early Technology: From incandescent and fluorescent lamps to LEDs (invented in the 1960s). 
• Breakthrough in 1993: Shuji Nakamura's team developed high-brightness blue LEDs, leading to energy-efficient white LEDs and winning the 2014 Nobel Prize in Physics. 
• Current Technologies:  
  • OLEDs: Thin, flexible, but costly with shorter lifespans. 
  • QLEDs: Precise color control, durable, but toxic with resource scarcity concerns. 
  • Micro/Mini-LEDs: High brightness and stability but expensive to produce.

Read More: Light Emitting Diodes (LED)

Unusual Rivers Around The World

Source: PR 

• Caño Cristales River, Colombia: It is also known as the "River of Five Colors," as it changes its color from yellow, green, black, red, and blue between July and November.  
  • This is due to Rhyncholacis clavigera, an aquatic plant that changes its color with sunlight and water conditions. 
• Shanay-Timpishka River, Peru: Also known as La Bomba, it is the world's largest thermal and only boiling river (with temperature 45oC to 100oC).  
  • It is heated by deep geothermal circulation where rainwater seeps underground, warms, and resurfaces through faults. 
• Hamza Aquifer (Hamza River): A vast underground aquifer beneath the Amazon River, ~4 km deep and 6,000 km long, flowing extremely slowly through porous rock formations. 
• Qiantang River, China: Known for the Silver Dragon, one of the world's largest tidal bores, where ocean tides push upstream at 40 km/hr, creating large waves ideal for surfing. 
• Daldykan River, Russia: Turned blood red due to nickel and heavy metals contamination. 
• Onyx River, Antarctica: The continent’s longest river (32 km), flowing inland toward Lake Vanda only in summer as meltwater from Wright Valley glaciers.

Read More: Transboundary Rivers of India