‘Fire count gives a skewed picture of stubble burning’
Context
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Govt claims: 92% reduction in fire counts in Punjab and 90% reduction in Haryana (since 2021).
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New study by iForest questions this, arguing fire counts undercount actual stubble burning.
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Alternative metric — Burnt Area — shows only ~30% reduction.
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Highlights risk of policy misinterpretation due to dependence on single-source satellite data.
Key Issue
Fire Counts ≠ Actual Stubble Burning
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Fire counts = number of active fires detected by satellites.
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Burnt area = actual land surface that shows evidence of burning.
iForest Findings
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Burnt area in Punjab + Haryana:
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31,500 sq km (2022) → 19,700 sq km (2025)
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≈30% decline, not 90%+.
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This mismatch suggests structural under-detection and flawed monitoring.
Why Fire Counts Are Misleading
a) Limited detection by Polar-Orbiting Satellites
India uses data from:
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MODIS (NASA’s Terra & Aqua)
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VIIRS (Suomi-NPP)
Limitations
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Observe India only during fixed time window: 10:30 a.m. – 1:30 p.m.
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Can detect only active flames at that moment → not 24-hour coverage.
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Miss small fires and short-duration fires.
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Seasonal haze or clouds further reduce detection
b) Time-of-Day Bias
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iForest analysis (using Meteosat SEVIRI):
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Most stubble fires since 2022 occur in the evenings.
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This is outside MODIS/VIIRS overpass times.
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Result → systematic undercounting of fires.
c) Resolution Issues
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MODIS: 1 km resolution → misses small field fires.
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VIIRS: 375 m resolution → better but still inadequate for scattered small fires.
What is ‘Burnt Area’? Why is it Better?
Burnt Area = Land surface that shows spectral signature of past burning
—not just active flames.
iForest used:
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Sentinel-2 (MSI instrument)
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100m × 100m resolution
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Detects burnt residue, char, ash
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Provides a more comprehensive picture
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Passes over every 5 days; data available with 8–15 day lag
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Despite limitations, it captures:
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Total area burned
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Fires missed by active detection sensors
Hence a more robust metric, especially for policy evaluation.
Role of Geostationary Satellites (Meteosat 8 & 9)
Advantages:
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Continuous monitoring (every 15 minutes)
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Detects fire timing patterns (e.g., evening peaks)
Limitations:
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Not suitable for precise fire count
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Lower spatial resolution → not ideal for small fires
Key Insight from SEVIRI:
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Majority of post-2022 fires occur after sunset
→ not captured by MODIS/VIIRS.
Implications for Air Quality & Policy
a) Undercount = Underestimated Emissions
Missed fires:
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Lead to underreported PM2.5, NOx, SOx emissions
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Distort air pollution models for Delhi NCR
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Affect emergency response & long-term mitigation planning
b) Policy Success May Be Overstated
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Govt measures (e.g., DSR promotion, ex-situ residue management, Happy Seeder) may appear more successful than they are.
c) Budget & incentive misallocation
Wrong data →
Wrong hotspots →
Ineffective targeting of:
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Machinery subsidies
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Enforcement drives
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Crop residue management funds
Broader Governance Problem
Over-reliance on a single metric
Using fire counts alone → Unidimensional indicator → Risk of data-driven misgovernance
Need for integrated monitoring
Combine:
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Fire counts (MODIS/VIIRS)
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Burnt area (Sentinel-2)
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Temporal monitoring (SEVIRI)
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Ground surveys
A multi-sensor approach ensures reliability.
Conclusion
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Fire counts provide a partial and skewed picture.
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Burnt area estimation, despite lags, gives a truer reflection of ground realities.
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For effective policy and accurate pollution assessment, India needs:
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Multi-sensor satellite integration
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Transparent data sharing
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Ground-level validation
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Policy recalibration based on actual burnt area
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