5 months ago
1
The usage of ‘fire counts,’ — satellite-derived estimates of progressive fires — to gauge the grade of stubble burning successful Punjab and Haryana whitethorn beryllium misleading.
The Environment Ministry has repeatedly claimed that occurrence counts successful Punjab and Haryana fell by 92% and 90% respectively since 2021, citing this arsenic grounds of a crisp diminution successful stubble burning and impervious of the effectiveness of measures successful the 2 states.
However, erstwhile information from a antithetic outer were utilized to compute different parameter called ‘burnt area,’ — the existent onshore country affected by occurrence — the simplification was much gradual, astatine astir 30%, falling from astir 31,500 sq km successful 2022 to 19,700 sq km successful 2025 (as of Nov 25th), says a survey by iForest, a probe outfit, that analysed information from aggregate satellites utilized to way stubble burning successful Punjab and Haryana.
“The authorities should halt utilizing occurrence counts arsenic a proxy for gauging a diminution oregon summation successful stubble burning,” said iForest CEO Chandra Bhushan, adding, “The fume that is detected by outer sensors offers amended practice of the onshore burned. Small fires are often missed by satellites.”
Currently, each of India’s authoritative estimates trust connected information provided by the Consortium for Research connected Agroecosystem Monitoring and Modeling from Space (CREAMS) of the Indian Agricultural Research Institute (IARI) and are built connected NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) connected the Terra and Aqua satellites and the Visible Infrared Imaging Radiometer Suite (VIIRS) connected the Suomi-NPP satellites.
These satellites orbit the Earth’s poles and observe India lone astatine fixed times of the day, from 10:30 americium to 1:30 pm. Their sensors are lone capable to seizure progressive fires and incapable to compute the existent fig of fires over, say, a 24-hour period.
“These monitoring gaps person far-reaching implications. Fires missed by polar-satellite sensors pb to underestimated emissions, mischaracterised aerosol and particulate-matter loads, and incorrect simulations of air-quality dynamics crossed India,” a property connection from iForest noted. “For example, the publication of stubble burning to Delhi’s aerial contamination was highly underestimated this twelvemonth due to the fact that MODIS/VIIRS captured lone a tiny fraction of progressive occurrence counts. This bias present affects policymaking and regulatory action, weakening the grounds based connected which interventions are designed.”
To get astatine their burnt country estimates, iForest utilized information from the Multi-Spectral Instrument of the Sentinel satellite. Though besides a polar-orbiting satellite, passing implicit India lone astir erstwhile successful 5 days and whose information is disposable lone with a lag of 8-15 days, it is the lone 1 of its benignant capable to cipher ‘burnt area’ astatine a solution of 100m by 100m.
Another acceptable of outer information utilized successful the investigation was the Meteosat 8 and 9, with the sensors Spinning Enhanced Visible and Infrared Imager (SEVIRI). Unlike the different satellites, this 1 is ‘geostationary,’ meaning it continuously looks astatine the aforesaid spot and can, thus, supply information each 15 minutes. However, this outer cannot cipher the ‘burnt area’ and tin lone compute occurrence counts (like MODIS and VIIRS). Situated 36,000 km from Earth, it could lone observe ‘large fires’ with a overmuch coarser solution of 4km x 6km. “While it mightiness not supply close accusation connected occurrence counts, this outer information intelligibly showed that since 2022, astir of the fires were concentrated successful the evenings - extracurricular the detection clip of the polar satellites. In Haryana, fires person ever been acceptable astir evening. Which means that the existent fig of fires successful the authorities has ever been undercounted,” said Mr Bhushan.
A survey published past period successful the peer-reviewed diary Current Science, led by scientists astatine the Space Applications Centre, ISRO, besides utilized SEVERI information to underline that stubble burning had shifted towards the evening to debar polar satellites and that determination was an expanding inclination successful fires implicit Punjab from 2020 to 2024, whereas VIIRS and MODIS information suggested a declining trend. The scientists, successful their study, said that some polar and geostationary-satellite information ought to beryllium utilized for an close representation of stubble burning.
While the authorities is alert of the limitations of its outer investigation and has been ordered by the Supreme Court to behaviour a “more thorough” probe into occurrence counts successful the “evening,” it inactive hasn’t publically released the burnt country data, citing methodological limitations. “While determination has been immoderate occurrence successful limiting workplace fires successful Punjab, a batch much enactment is required. The publication of stubble burning is overmuch much than the 5% -10% presently assumed,” Bhushan added.
