Farm fires impact Delhi air, but only measly

The share of stubble burning to Delhi’s PM 2.5 concentration was 3% on Wednesday, the System of Air Quality and Weather Forecasting And Research (SAFAR) said

Stubble burning has begun to impact Delhi’s air quality, which deteriorated to the ‘poor’ category on Thursday after four consecutive ‘moderate’ air days. The share of stubble burning to Delhi’s PM 2.5 concentration was 3% on Wednesday, with it being 0% in the four days prior to that, the System of Air Quality and Weather Forecasting And Research (SAFAR) said on Thursday. The body estimated the contribution of farm fires on Thursday to be similar – between 1-3%, stating an approaching western disturbance from October 14-17 is likely to change the wind direction once again and bring this number down.

Delhi’s 24-hour average air quality index (AQI) was recorded at 220 (poor) -- the highest so far this winter season. (Sunil Ghosh/HT Photo)

Delhi’s 24-hour average air quality index (AQI) was recorded at 220 (poor) -- the highest so far this winter season. In comparison, the AQI had been 193 (moderate) on Wednesday and 180 (moderate) on Tuesday.

“Until Tuesday, the wind direction was easterly-southeasterly, but it changed to northwesterly on Wednesday, which began to bring pollutants towards Delhi again. On Thursday, meteorological conditions did not change much and we expect a similar contribution between 1 and 3%,” said Gufran Beig, founder project Director at SAFAR and chair professor, NIAS.

So far, till October 11, Punjab has recorded 1,063 farm fires, with Haryana recording 340 fires. At the same time last year, the count in Punjab was 763 and it was 83 in Haryana, satellite data collated by the Indian Agricultural Research Institute (IARI) showed.

Dipankar Saha, former head of Central Pollution Control Board’s air laboratory said farm fires have begun early this year as northwest India has seen far lesser rain this September, in comparison to last year, when rain was also being recorded in early October. He, however, said a higher count at this stage was more beneficial for Delhi’s air.

“Early fires are better as the more the delay in burning, the worse the meteorological conditions are at that time of the year. This makes it more favourable for pollutants to get trapped. Last year, this burning was delayed and it led to higher pollution in end October and early November, when meteorological conditions are not ideal.” he said.

Beig says that the contribution trend so far has been similar to last year, with this figure rising not only when the daily fire count rises, but also when the wind direction is northwesterly for a sustained period. “At present, local wind speed, particularly during the day is still good. For this stubble contribution to go in double digits, a high fire count is required, coupled with consistent northwesterly winds and calm winds over Delhi,” he said.

SAFAR’s data showed at the same time last year, the contribution of stubble burning to Delhi’s air was 0% on October 7 and 8; it was 3% on October 9, 2% each on October 10 and 11 and it rose to 4% on October 12, before dipping back down to 2% the next day. In fact, the daily contribution remained in single digits till October 28, rising abruptly from 7% that day to 21% the next day. A sharp rise in farm fire numbers is generally seen in the last week of October and the first week of November, when harvesting is at its peak. Generally, at this time, meteorological conditions are also unfavourable, like low temperature and calm winds.

Bio-decomposer to be sprayed in Delhi

Delhi development minister Gopal Rai on Thursday said the government will begin spraying the bio-decomposer solution developed by the Indian Agricultural Research Institute (IARI) over Delhi’s farm fields from Friday onwards, with fields identified in north Delhi’s Tigipur and Narela.

The minister said the solution – sprayed on paddy fields post harvesting, helps decompose the stubble left behind in less than a month and prevents the need to burn stubble. This year, he said the government will spray it across 5,000 acres of farm fields in Delhi. Similar to last year, the activity will be done free of cost.

“The process of spraying commence from Tigipur and Narela. For this, 13 teams have been formed. This bio-decomposer will be sprayed for free by the government in all Basmati and non-Basmati paddy farms inside Delhi,” he said, adding that tackling stubble burning is part of the 15-point winter action plan of the Delhi government