Delhi’s air quality became severe on Diwali with stubble burning accounting for 32 per cent of the city’s PM2.5 pollution and calm winds worsening the situation as they allowed accumulation of pollutants, the weather officials said.
Delhi recorded a 24-hour average AQI of 337 on Diwali last year (October 27), and 368 and 400 in the next two days. Thereafter, pollution levels remained in the “severe” category for three days on the trot.
A fresh western disturbance is likely to increase the wind speed and improve the air quality in Delhi-NCR post the Diwali according to IMD.
Also, light rain is likely to fall on Sunday under the influence of a western disturbance. It is still to be seen if it is enough to wash away pollutants, Kuldeep Srivastava, the head of the IMD’s regional forecasting centre, said.
VK Soni, the head of the IMD’s environment research centre, said calm winds, smoke from farm fires and firecrackers emissions may push the air quality to the severe zone on Diwali night. The wind speed is expected to pick up thereafter and the wind direction will be east-southeasterly, he said.
There will be a significant improvement in air quality by November 16, he added.
The Air Quality Early Warning System for Delhi also said the situation is likely to improve significantly on Sunday. “Under the influence of a Western Disturbance, isolated rainfall over plains of northwest India and adjoining central India is likely on Sunday. The predominant surface wind is likely to be coming from East-Southeast direction of Delhi with wind speed up to 20 kmph,” it said.
The National Green Tribunal (NGT) had on Monday imposed a total ban on sale or use of all kinds of firecrackers in the National Capital Region (NCR) from November 9 midnight to November 30 midnight, saying “celebration by crackers is for happiness and not to celebrate deaths and diseases”.
A bench headed by NGT chairperson Justice Adarsh Kumar Goel clarified that the direction will apply to all cities and towns in the country where the average of ambient air quality during November 2019 was in “poor” and above categories. “At other places, restrictions are optional for the authorities but if there are more stringent measures under orders of the authorities, the same will prevail,” the NGT had said.