ISRO Study Reveals Underestimated Farm Fires Due to Shift in Stubble Burning Times
An ISRO study suggests official farm fire data in Punjab and Haryana might be an undercount, as stubble burning activity has shifted to later hours, affecting satellite detection.
Photo by Aurora K
त्वरित संशोधन
ISRO's Space Applications Centre (SAC) study flags a shift in peak farm-fire activity in Punjab and Haryana.
Peak burning has shifted from early afternoon to early evening since 2020.
Official data, based on polar orbiting satellites, may be 'undercounting' actual farm fires.
ISRO study used geostationary Meteosat Second Generation (MSG) satellites with SEVIRI sensor.
Official data relies on NOAA's Suomi NPP and NASA's Terra MODIS and Aqua MODIS satellites.
महत्वपूर्ण तिथियां
दृश्य सामग्री
Stubble Burning Hotspots & Monitoring Hub
This map illustrates the primary regions affected by stubble burning (Punjab & Haryana), the national capital (Delhi) which bears the brunt of air pollution, and the location of ISRO's Space Applications Centre (SAC) in Ahmedabad, which conducted the study.
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Satellite Monitoring: Polar Orbiting vs. Geostationary
This table compares the two main types of Earth observation satellites, highlighting why the shift in stubble burning times makes polar-orbiting satellites less effective for current monitoring, as revealed by the ISRO study.
| Feature | Polar Orbiting (Sun-synchronous) Satellites | Geostationary Satellites |
|---|---|---|
| Orbit Type | Low Earth Orbit (LEO), passes over poles | Geostationary Earth Orbit (GEO), above equator |
| Altitude | Typically 700-800 km | Approximately 35,786 km |
| Coverage | Global coverage, but specific areas are observed infrequently (e.g., once or twice a day) | Continuous, real-time monitoring of a specific large region (e.g., a continent) |
| Revisit Time | Fixed local solar time passes (e.g., 10:30 AM, 1:30 PM) | Constant view of the same area |
| Stubble Burning Detection (Traditional) | Effective when fires peak during fixed pass times (e.g., early afternoon) | Less commonly used for localized fire detection due to lower spatial resolution, but offers continuous monitoring |
| Stubble Burning Detection (New Shift) | Prone to 'undercount' as peak activity shifts to early evening, missing fixed pass times | Better suited for detecting fires that occur outside fixed time windows due to continuous monitoring capability |
परीक्षा के दृष्टिकोण
Environmental pollution (air quality, climate change)
Agricultural practices and their sustainability
Role of space technology in environmental monitoring
Government policies and their effectiveness (e.g., Crop Residue Management, CAQM)
Inter-state environmental issues and federal challenges
विस्तृत सारांश देखें
सारांश
A new study by ISRO's Ahmedabad-based Space Applications Centre (SAC) has thrown a new light on the persistent issue of farm fires in Punjab and Haryana. While official data indicates a decline in stubble burning incidents, the ISRO study suggests this might be an 'undercount.' What's happening? The study, using data from European geostationary satellites, found a gradual shift in peak farm-fire activity from early afternoon to early evening since 2020.
This shift means that the sun-synchronous polar orbiting satellites, which are typically used for official monitoring and pass over at fixed times, might be missing many of these later-day fires. Essentially, the problem of stubble burning and its contribution to air pollution could be more severe than official figures suggest, posing a challenge for effective policy intervention and monitoring.
पृष्ठभूमि
नवीनतम घटनाक्रम
The recent ISRO study highlights a critical gap in the official monitoring of farm fires. By identifying a shift in peak burning activity from early afternoon to early evening, it suggests that the traditional sun-synchronous polar orbiting satellites, which pass over at fixed times, are likely undercounting the actual incidents.
This underestimation implies that the problem of stubble burning and its contribution to air pollution is potentially more severe than official figures suggest, posing a significant challenge for effective policy formulation and intervention. The study leverages European geostationary satellites, which offer continuous monitoring, to reveal this temporal shift.
बहुविकल्पीय प्रश्न (MCQ)
1. Consider the following statements regarding the recent ISRO study on farm fires: 1. The study was conducted by the Space Applications Centre (SAC) located in Bengaluru. 2. It found a shift in peak farm-fire activity from early afternoon to early evening in Punjab and Haryana since 2020. 3. The study suggests that sun-synchronous polar orbiting satellites might be undercounting farm fires due to this temporal shift. Which of the statements given above is/are correct?
- A.1 and 2 only
- B.2 and 3 only
- C.3 only
- D.1, 2 and 3
उत्तर देखें
सही उत्तर: B
Statement 1 is incorrect. The news states SAC is based in Ahmedabad, not Bengaluru. Statement 2 is correct, as the study explicitly identified this temporal shift in peak farm-fire activity. Statement 3 is also correct, as the core finding is that polar orbiting satellites, due to their fixed pass-over times, miss these later-day fires, leading to an undercount.
2. With reference to satellite orbits and their applications in Earth observation, consider the following statements: 1. Geostationary satellites maintain a fixed position relative to a point on Earth's surface, making them suitable for continuous monitoring of specific regions. 2. Sun-synchronous polar orbiting satellites pass over the same spot on Earth at the same local mean solar time each day, providing consistent lighting conditions for imaging. 3. The European geostationary satellites mentioned in the ISRO study primarily provide high-resolution imagery for detailed land-use mapping. Which of the statements given above is/are correct?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
उत्तर देखें
सही उत्तर: A
Statement 1 is correct. Geostationary satellites orbit at a high altitude above the equator and match Earth's rotation, appearing stationary from the ground. This makes them ideal for continuous monitoring. Statement 2 is correct. Sun-synchronous orbits ensure consistent lighting conditions, which is crucial for remote sensing applications that require comparing images taken at different times. Statement 3 is incorrect. While geostationary satellites provide continuous monitoring, their high altitude generally means lower spatial resolution compared to low-Earth orbit satellites. The ISRO study used them for their continuous temporal coverage to detect the *shift in burning times*, not primarily for high-resolution land-use mapping.
3. In the context of addressing stubble burning in North India, which of the following statements correctly describes the 'in-situ' and 'ex-situ' crop residue management strategies? A) 'In-situ' management primarily involves converting crop residue into bio-ethanol, while 'ex-situ' focuses on using Happy Seeder for direct sowing. B) 'In-situ' strategies include the use of PUSA decomposer and Super Seeder, whereas 'ex-situ' strategies involve collecting stubble for biomass power generation. C) 'In-situ' refers to the collection and transportation of stubble to industrial units, while 'ex-situ' involves burning residue in controlled environments within the field. D) Both 'in-situ' and 'ex-situ' strategies are primarily focused on providing financial incentives to farmers for not burning stubble.
- A.'In-situ' management primarily involves converting crop residue into bio-ethanol, while 'ex-situ' focuses on using Happy Seeder for direct sowing.
- B.'In-situ' strategies include the use of PUSA decomposer and Super Seeder, whereas 'ex-situ' strategies involve collecting stubble for biomass power generation.
- C.'In-situ' refers to the collection and transportation of stubble to industrial units, while 'ex-situ' involves burning residue in controlled environments within the field.
- D.Both 'in-situ' and 'ex-situ' strategies are primarily focused on providing financial incentives to farmers for not burning stubble.
उत्तर देखें
सही उत्तर: B
'In-situ' (on-site) management involves dealing with crop residue within the field itself, such as using machinery like Happy Seeder, Super Seeder for direct sowing, or biological decomposition using PUSA decomposer. 'Ex-situ' (off-site) management involves removing the crop residue from the field and utilizing it elsewhere, like for biomass power plants or bio-ethanol production. Option B correctly identifies these distinctions.
4. Assertion (A): The Commission for Air Quality Management (CAQM) in National Capital Region and Adjoining Areas Act, 2021, was established to address air pollution, including stubble burning, with statutory powers. Reason (R): The Supreme Court of India had previously highlighted the need for a permanent, comprehensive, and expert body to tackle the complex issue of air pollution in the Delhi-NCR region. In the context of the above two statements, which one of the following is correct?
- A.Both A and R are true, and R is the correct explanation of A.
- B.Both A and R are true, but R is not the correct explanation of A.
- C.A is true, but R is false.
- D.A is false, but R is true.
उत्तर देखें
सही उत्तर: A
Assertion (A) is true. The CAQM was indeed established by an Act of Parliament in 2021 to provide a statutory framework for air quality management in the NCR and adjoining areas, specifically addressing stubble burning. Reason (R) is also true. The Supreme Court, through various judgments, had repeatedly emphasized the need for a dedicated, permanent, and expert body to address the persistent air pollution crisis in the Delhi-NCR, which directly led to the formation of CAQM. Therefore, R is the correct explanation of A.