The Centre for Science and Environment (CSE) said stubble burning-related smokefall over Delhi depended on two major factors -- the number and intensity of farm fires and meteorological conditions conducive for the transportation of the smoke to the national capital.
Not only have the number of farm fires in Punjab and Haryana this season been the lowest since 2016, the national capital also witnessed the least smoke intrusion from stubble burning during October-November in four years, according to a Centre for Science and Environment analysis.
Analysis of data from SAFAR, the Union Ministry of Earth Sciences' air quality forecasting agency, shows that smoke from farm fires contributed to PM2.5 pollution in Delhi on 53 days this year, starting October 12. The figure is lower than the previous three years when smoke intrusion was reported on 56-57 days but higher than the 2018 reading of 48 days.
The highest contribution this year was 34 per cent on November 3. Last year, the share of farm fires in Delhi's PM 2.5 pollution peaked to 48 per cent on November 7. The Centre for Science and Environment (CSE) said stubble burning-related smokefall over Delhi depended on two major factors -- the number and intensity of farm fires and meteorological conditions conducive for the transportation of the smoke to the national capital.
This October-November, not only have the quantity and intensity of farm fires been comparatively lower but also the meteorological conditions less conducive for transport of the smoke, the green think tank said. The CSE estimated that smoke from farm fires accounted for 4.1 tonnes of PM2.5 during October-November in Delhi. This is 37 per cent lower than 6.4 tonnes of PM2.5 from stubble burning last year and almost half the 2020 figure (8 tonnes).
The volume this year is also significantly lower than the 2019 figure (6.4 tonnes) -- an indicator of the meteorological help Delhi got as there were fewer farm fires in 2019. According to the Indian Agriculture Research Institute, Punjab, which accounts for the maximum cases of stubble burning every year, reported just 49,922 farm fires this season (September 15 to November 30) against 71,304 last year and 83,002 in 2020.
The agrarian state logged 50,738 incidents of stubble burning in 2019; 59,684 in 2018; 67,079 in 2017 and 1,02,379 in 2016. Haryana logged 3,661 farm fires this season against 6,987 in 2021 and 4,202 in 2020. The neighbouring state saw 6,364 incidents of stubble burning in 2019; 9,225 in 2018; 13,085 in 2017 and 15,686 in 2016.