INTEGRATED MAINS AND PRELIMS MENTORSHIP (IMPM) 2025 Daily KEY
| Exclusive for Subscribers Daily:
Northeast Monsoon and Stubble burning its significance for the UPSC Exam? Why are topics like Cloud seeding, Special Intensive Revision important for both preliminary and main exams? Discover more insights in the UPSC Exam Notes for October 24, 2025 |
How do monsoons affect Tamil Nadu?
For Preliminary Examination: Current events of national and international Significance like Indian Monsoons
For Mains Examination: GS I - World Geography
Context:
The northeast monsoon has kicked in early this year, at least four days sooner for the second year running, over Tamil Nadu. Last year, this phase of the monsoon ended with the State recording 33% more rain than the long-period average, and forecasters expect this year to go the same way.
Read about:
Southwest Monsoon
Northeast Monsoon
Key takeaways:
- The northeast monsoon has arrived ahead of schedule this year, marking its onset over Tamil Nadu nearly four days earlier than usual — the second consecutive year this has happened. In 2024, the same monsoon phase ended with 33% more rainfall than the long-term average, and meteorologists predict a similar trend this year as well.
- Traditionally, policymakers and state administrations have treated surplus rainfall as beneficial, particularly for agriculture and water storage. However, climate change has begun to challenge this assumption.
- Although the total volume of rain has increased, precipitation is now occurring in short, intense, and localized bursts. These concentrated downpours overwhelm the natural and built environment, often causing more harm than good. It is therefore becoming necessary to rethink the belief that “more rain is always better.”
- In urban areas, impervious surfaces such as roads and pavements prevent rainwater from being absorbed into the ground. This results in rapid surface runoff, which can overwhelm stormwater drains and lead to flash floods, waterlogging in low-lying areas, damage to property, and traffic disruptions.
- During such events, as seen in Cyclone Michaung and Tamil Nadu’s floods in 2023, authorities often cut electricity to prevent accidents from loose cables. The large volume of water also triggers sewage overflow, sending untreated wastewater into streets and waterbodies — a major health and environmental hazard.
- The agricultural sector too faces significant challenges from excessive rain. Waterlogged soil suffocates plant roots, washes away seeds, young crops, and nutrient-rich topsoil, thereby reducing soil fertility over time. Moreover, the high moisture encourages fungal infections and pest infestations, leading to lower crop yields and financial losses for farmers.
- Heavy rains can also wash fertilizers and pesticides into rivers and reservoirs, degrading water quality. Standing water after floods provides ideal breeding conditions for mosquitoes, contributing to the spread of vector-borne diseases such as malaria, dengue, and zoonotic infections like leptospirosis and Japanese encephalitis.
- Beyond these immediate effects, prolonged heavy rainfall raises the groundwater table, which can weaken the foundations of buildings, roads, and other infrastructure.
- A persistently high water table exerts pressure on basements, causes cracks, leaks, and mold growth, and reduces the soil’s ability to bear loads. Over time, this can result in structural instability and costly damage.
- The economic and social repercussions are far-reaching. Rebuilding damaged infrastructure, rehabilitating farmland, and repairing homes require substantial public expenditure. Meanwhile, disruptions to transport, businesses, and daily life slow down economic activity.
- In some cases, flooding and landslides displace communities or lead to casualties, especially among vulnerable groups. The psychological impact — including trauma, stress, and anxiety — adds another layer of long-term consequence often overlooked in disaster management.
- Tamil Nadu faces unique vulnerabilities due to its geographical and climatic conditions. Unlike Kerala, which primarily receives rainfall from the southwest monsoon (June–September), Tamil Nadu’s main rainy season comes during the northeast monsoon (October–December). Problems arise when these two systems overlap or both bring heavy rains simultaneously — as is happening with this year’s early northeast monsoon.
- This overlap complicates water management, especially concerning the Mullaperiyar Dam, situated in Kerala’s Idukki district but operated by the Tamil Nadu government.
- The dam’s catchment area lies in Kerala, and rainfall there directly influences water inflow into Tamil Nadu’s river systems. When heavy rains hit Kerala’s catchments, the Mullaperiyar reservoir fills rapidly, forcing Tamil Nadu authorities to release water to ensure dam safety.
- The released water flows in two directions — one toward Kerala’s Periyar River, risking floods in Idukki, and the other toward Tamil Nadu’s Vaigai Dam. If Tamil Nadu is already receiving heavy monsoon rains, this creates a double burden, with both internal and transboundary flooding risks
Follow Up Question
Mains
Q. “In the context of climate variability and rapid urbanisation, excess rainfall is no longer a sign of abundance but a growing environmental and infrastructural challenge.”
Discuss this statement with reference to the recent pattern of northeast monsoon rainfall in Tamil Nadu.
|
Note: This is a reference Structure answer and Model answer only
|
|
Answer (C)
|
Is Punjab’s stubble burning problem really declining?
For Preliminary Examination: Current events of national and international Significance
For Mains Examination: GS III - Environment and Ecology
Context:
Paddy harvesting has picked up momentum in Punjab, the country’s key grain-producing State, and so have stubble burning incidents. This year, stubble burning has been relatively fewer because the State faced one of its worst floods in decades, leaving vast stretches of farmland inundated
Read about:
What is Stubble burning?
Are stubble burning incidents declining?
Key takeaways:
- The harvesting of paddy has gained pace in Punjab, one of India’s major grain-producing States, and with it, the annual problem of stubble burning has reappeared. However, the number of farm fires this year has been comparatively lower.
- This decline is largely attributed to the severe floods that struck Punjab earlier in the year, submerging large tracts of farmland and delaying agricultural operations.
- Every year, as autumn approaches, the burning of paddy residue becomes a major environmental concern, contributing significantly to the deterioration of air quality across northern India, including the National Capital Region (NCR).
- Paddy harvested with combine harvesters leaves short stalks on the field, and farmers often find it most convenient to burn these remains to quickly prepare the soil for wheat sowing, which must begin within a narrow window of about three weeks.
- This short turnaround period, combined with the cost and labour involved in alternative disposal methods, drives many farmers toward this practice.
- Both the Central and State governments have claimed success in reducing the frequency of stubble burning through stricter monitoring, awareness campaigns, and by providing subsidised residue management equipment.
- Official satellite-based data from the Punjab government indicates a 70% fall in reported fire incidents in 2024 — from 36,663 cases in 2023 to 10,909 cases this year.
- Yet, despite this apparent progress, the total area affected by burning has shown little change. Data from the Punjab Remote Sensing Centre (PRSC) and the Punjab Pollution Control Board (PPCB) reveal that around 19.17 lakh hectares of farmland were affected by residue burning in 2024, almost the same as the 19.14 lakh hectares recorded the previous year.
- Earlier figures show that around 15.4–15.6 lakh hectares were affected in 2021–2022, indicating a gradual expansion over time.
- Experts caution that while the number of fire events detected has declined, the actual burnt area may have increased due to several factors. Satellite sensors often miss small, low-intensity, or short-duration fires, particularly those occurring in fragmented farmlands.
- Since satellites such as MODIS and VIIRS pass over Punjab only a few times a day, and most fires are lit in the late afternoon or evening, many are not captured. Additionally, haze, smoke, and cloud cover can obscure active fires, leading to underreporting.
- A recent study by the Indian Institute of Science Education and Research (IISER), Mohali, published in Science of the Total Environment, underscores these limitations. It also notes that some farmers, aware of satellite monitoring, may attempt to conceal burnt fields before the next satellite pass.
What is Stubble Burning?
- Stubble burning is the practice of setting fire to crop residue — the dry stalks, roots, and leaves left behind in the field after harvesting — primarily to clear the land quickly for the next planting season.
- In India, this practice is most common in Punjab, Haryana, and parts of western Uttar Pradesh, where paddy (rice) is grown during the kharif season and followed immediately by wheat cultivation in the rabi season.
- Because the time gap between harvesting paddy (usually in October) and sowing wheat (by mid-November) is short — roughly two to three weeks — farmers often find burning the leftover straw to be the fastest and cheapest way to prepare their fields.
- Modern combine harvesters, while efficient at harvesting paddy, leave behind stubble that is too short for mechanical collection and too tough for cattle feed.
- Removing or managing it mechanically requires expensive equipment and additional labour, which many small and marginal farmers cannot afford. As a result, burning becomes the most convenient option.
- However, this method has serious environmental and health consequences. It releases large amounts of particulate matter (PM2.5 and PM10), carbon monoxide (CO), nitrous oxide (Nâ‚‚O), and volatile organic compounds, which contribute to air pollution and smog, especially in northern India. The practice also depletes soil nutrients, reduces microbial activity, and damages soil health over time.
- Thus, while stubble burning offers short-term convenience, it leads to long-term environmental degradation, public health hazards, and climate challenges, making it a major policy concern in India’s agricultural and environmental governance
Follow Up Question
Q. “Stubble burning reflects the intersection of environmental neglect, agrarian distress, and policy gaps.”
Examine the causes and consequences of stubble burning in India and suggest sustainable alternatives to address this issue.
|
Note: This is a reference Structure answer and Model answer only
|
Prelims
1.Acid rain is caused by the pollution of the environment (UPSC 2013, 2022)
(a) Carbon Dioxide and Nitrogen
(b) Carbon Monoxide and Carbon Dioxide
(c) Ozone and Carbon Dioxide
(d) Nitrous Oxide and Sulphur Dioxide
|
Answer (d)
Acid rain occurs when pollutants such as Sulphur Dioxide (SOâ‚‚) and Nitrogen Oxides (NOâ‚“) are released into the atmosphere—mainly from the burning of fossil fuels in industries, vehicles, and power plants. These gases react with water vapour, oxygen, and other chemicals in the atmosphere to form sulphuric acid (Hâ‚‚SOâ‚„) and nitric acid (HNO₃). These acids then mix with rainwater, lowering its pH, and fall as acid rain Impact:
Remember — Acid rain = SOâ‚‚ + NOâ‚“ → Hâ‚‚SOâ‚„ + HNO₃ (acidic compounds)
|
Why cloud seeding is not a solution to Delhi’s air pollution crisis?
For Preliminary Examination: Current events of national and international Significance
For Mains Examination: GS III - Science and technology, Environment and ecology
Context:
Delhi’s plan for cloud seeding is being sold as a bold solution to air pollution. In reality, it is a textbook case of science misapplied and ethics ignored.
Read about:
What is Cloud seeding?
What is Acid rain?
Key takeaways:
- Cloud Seeding is a scientific method used to modify weather conditions, primarily aimed at inducing or increasing rainfall. The process involves introducing specific substances into clouds that already contain some amount of moisture.
- These substances, such as silver iodide, potassium iodide, or common salt (sodium chloride), act as nuclei around which water vapour can condense and form droplets. When enough droplets combine, they grow heavy enough to fall as rain.
- This method can be carried out in two main ways. One approach involves using aircraft that fly through clouds to disperse the seeding agents directly.
- Another method uses ground-based generators, which release the particles upward into the atmosphere where they are carried by wind currents into suitable cloud formations.
- Once the particles reach the clouds, they trigger the condensation process that leads to rainfall.
- Cloud seeding is often used in regions facing drought conditions to enhance rainfall and replenish water sources. It has also been applied to disperse fog around airports for improving visibility and to reduce the size of hailstones in hail-prone areas, thereby minimizing crop damage.
- However, the effectiveness of cloud seeding is not always guaranteed. It depends heavily on factors like the presence of suitable clouds, temperature, and humidity levels. There are also environmental concerns regarding the chemicals used, as well as debates over its ethical and geopolitical implications when weather modification affects neighbouring regions.
- In India, states such as Karnataka, Maharashtra, and Telangana have undertaken cloud seeding experiments under projects like Varshadhare and Project Varsha to combat drought and increase rainfall.
- Thus, cloud seeding represents a blend of meteorology and technology that attempts to influence nature’s processes for human benefit, though its outcomes remain variable and context-dependent
Additional Information
- During the winter months, Delhi’s air quality worsens dramatically, turning far more toxic than in other seasons. While much of North India faces pollution year-round, it is during the post-monsoon and winter period that the situation becomes particularly severe.
- Once the monsoon withdraws, the region is dominated by dry continental air masses blowing in from the northwest. These winds weaken, creating stagnant atmospheric conditions that prevent pollutants from dispersing.
- As temperatures drop, cooler air holds less moisture, and the stable high-pressure systems typical of winter restrict the upward movement of air. This lack of vertical mixing traps pollutants near the surface.
- The resulting haze often seen in Delhi’s skyline is therefore not from clouds but from accumulated pollution. Moreover, the atmosphere during these months is too dry and stable to support significant rainfall, which could otherwise help wash away pollutants.
- The little rain that does occur is usually due to western disturbances — weather systems originating in the Mediterranean that occasionally bring moisture into North India — but these are sporadic and unreliable.
- Cloud seeding is often suggested as a possible solution, but its effectiveness is highly questionable. The process requires natural clouds to exist — it cannot create them — and even when conditions seem favourable, studies show that it only sometimes leads to increased rainfall.
- Moreover, any relief from pollution following such rainfall tends to be very short-lived, with air quality deteriorating again within a day or two. Many experts argue that cloud seeding, like smog towers, represents a distraction from the deeper structural reforms needed to tackle air pollution at its root.
- There are also potential environmental and ethical concerns linked to cloud seeding. The process involves dispersing substances such as silver iodide or sodium chloride into the atmosphere to stimulate condensation.
- While silver iodide’s structure mimics that of ice and helps initiate rainfall, repeated use could lead to its accumulation in soil and water systems, posing unknown risks to ecosystems, crops, and human health.
- Another major issue is accountability. If cloud seeding coincides with heavy rainfall or flooding, it becomes difficult to determine responsibility for any resulting damage. Even when unrelated, such incidents could erode public trust in scientific methods and government institutions.
- Therefore, while cloud seeding might seem like an innovative quick fix, its uncertain results, environmental implications, and ethical dilemmas make it an unreliable and risky strategy for addressing Delhi’s worsening winter smog
|
Note: This is a reference Structure answer and Model answer only
|
1.In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere? (UPSC CSE 2019)
(a) Creating the artificial rains in some regions
(b) Reducing the frequency and intensity of tropical cyclones
(c) Reducing the adverse effects of solar wind on the Earth
(d) Reducing the global warming
|
Answer (d)
Both cirrus cloud thinning and sulphate aerosol injection are geoengineering techniques proposed to mitigate global warming by managing the amount of solar radiation that reaches or remains trapped in the Earth’s atmosphere.
Both methods fall under Solar Radiation Management (SRM) — a form of climate engineering — designed to counteract the warming effects of greenhouse gases, though they remain controversial due to uncertain side effects and ethical concerns. |
- Article 324(1) of the Indian Constitution empowers the Election Commission of India (ECI) with the authority to supervise, direct, and control the preparation of electoral rolls and the conduct of elections to Parliament and State legislatures.
- Complementing this, Section 21(3) of the Representation of the People Act, 1950, authorises the ECI to order a special revision of electoral rolls for any constituency whenever it deems necessary and in any manner it considers appropriate.
- As per the Registration of Electors’ Rules, 1960, electoral roll revisions can be conducted in three ways — intensively, summarily, or in a combination of both. An intensive revision involves preparing a fresh roll from scratch, while a summary revision entails updating or correcting the existing list.
- Typically, special summary revisions are carried out annually and before each Lok Sabha and State Assembly election. Historically, intensive revisions were undertaken in specific years, such as 1952–56, 1957, 1961, 1965, 1966, 1983–84, 1987–89, 1992, 1993, 1995, 2002, 2003, and 2004.
- Recently, the Election Commission convened a two-day conference to evaluate the preparedness of Chief Electoral Officers (CEOs) from various States and Union Territories for a Special Intensive Revision (SIR). The nationwide revision is expected to be implemented in phases, starting with States like Assam, Kerala, Puducherry, Tamil Nadu, and West Bengal, which are due for elections next year.
- For this upcoming SIR, the ECI may allow voters to use extracts from electoral rolls of any State’s previous intensive revision — a relaxation compared to Bihar’s earlier process, where only extracts from Bihar’s last revision were accepted.
- The ECI has also directed CEOs to match as many electors as possible with previous intensive rolls to reduce the need for additional documentation.
- The SIR process began in Bihar following an order dated June 24, requiring all registered voters to fill enumeration forms and submit documents proving their date or place of birth, particularly those enrolled after 2003, to verify eligibility and citizenship.
- At a press briefing on October 6, the Chief Election Commissioner reaffirmed that a nationwide Special Intensive Revision was underway as per the June order, with dates for various States and UTs to be announced soon.
- However, this decision has been challenged in the Supreme Court, as it marks a shift from the two-decade-old practice of conducting annual summary revisions instead of preparing fresh rolls — a practice common before the computerisation of electoral data
Discuss the constitutional and legal basis of the Election Commission’s powers to revise electoral rolls. Critically analyse the implications of conducting a Special Intensive Revision for electoral transparency, inclusion, and administrative efficiency in India.
|
Note: This is a reference Structure answer and Model answer only
|
Prelims
|
Answer (D)
|