From November 4 onwards, the stubble burning-induced impact in Delhi’s air quality will lead to an increase in the level of PM 2.5 pollutants to up to 38 per cent due to change in the wind direction, System of Air Quality and Weather Forecasting and Research (SAFAR) said on Tuesday.
During November 4 to 6 (Diwali and the next two days), the expected share of stubble burning in PM2.5, as predicted by SAFAR, is likely to be in the range of 20 per cent to 38 per cent.
The peak levels of PM10 and PM2.5 are expected between 1 a.m. to 6 a.m. on Diwali night and November 5 morning.
“From November 4 onwards, the wind direction will change from the present easterly to north-westerly which are highly favourable to the intrusion of stubble burning,” SAFAR founder and project Director Gufran Beig told IANS.
“Even if 50 per cent of the firecrackers burst in 2020 happen to be lit this Diwali, then the air quality will deteriorate to ‘severe’, and without crackers, the air quality will settle at upper end of ‘very poor’ on November 5 and 6,” he added.
The AQI is predicted to improve slightly on November 6 but will fluctuate between the high-end of “very poor” to the “severe” range.
“This is mainly due to the coincidence of all three critical factors with a peak PM2.5 surpassing 300 microgrammes/m3 on November 5. The stubble fire share in Delhi’s PM2.5 is forecast to be between 20-40 per cent during November 4 to 6 if fire counts are assumed to be similar to last year. The peak in share 40 per cent will touch on November 5, if fire counts are assumed to be 4,000 as expected,” it added.
On November 3, the overall air quality of Delhi will continue to remain in the upper end of “very poor” category.