Punjab farm fires up by nearly 90% over daily average of past 5 years: Study

The number of crop stubble fires in neighbouring Punjab registered an increase of 89.7% this year when compared to the average daily fire counts over the past five years, according to an analysis of satellite data done by a team of scientists at the Indian Institute of Technology (IIT)-Delhi.

Scientists at IIT-Delhi’s Centre of Excellence for Research on Clean Air (CERCA), who did the analysis, said the number of fire counts almost doubled this year in most districts of Punjab, which contributed majorly to the high PM 2.5 levels --- the most harmful aerosols in Delhi’s air in October-November..

In the case of Haryana, however, the fire counts reduced by 18% when compared to the average daily fire counts over the past five years.

“This year, crop stubble burning started earlier than usual because of early harvest of some paddy varieties. Farm fires started from late September itself, which usually starts from the first week of October. The satellite data analysed from September 22 to November 18 of farm fires in Punjab shows there was an 89.7% increase in the number of fire counts, as compared to the average daily fire counts over the past five years,” said Sagnik Dey, associate professor, Centre for Atmospheric Sciences and coordinator, CERCA at IIT-Delhi.

On any given day, Dey said, the number of daily fires was almost double the average daily count over the past five years. Between November 5 and 10, Delhi saw six consecutive days of ‘severe’ air. On November 5, the number of total fire counts in Punjab was 5,107, much higher than 3,191, the average fire count recorded on the same day during 2015-19. Similarly, on November 6 and 7 this year, the fire counts were 4,130 (against the average count of 3,043 in the past five years) and 5,076 (against the average count of 2,747).

Also Read: AAP writes to air quality panel, points role of farm fires in Delhi’s pollution

“The fire counts started showing a downward trend only after November 14. However, a slight increase was again noticed on November 17-18, the impact of which could also be seen in the current air quality,” said Dey.

Krunesh Garg, member secretary, Punjab Pollution Control Board (PPCB), said the number of fire counts this year was higher, but data was still being collated to ascertain the reasons behind the rise.

“In the analysis so far, the burnt area has not increased. Even though the area under paddy cultivation was less this year than last year, what could possibly be one of the factors behind the rise (of fires) is an increase in productivity. Data is being collated to substantiate it and it will take another 8-10 days for a complete analysis,” said Garg.

According to the System of Air Quality and Weather Forecasting and Research (SAFAR), the union ministry’s air quality forecasting wing, the contribution of farm fires to PM 2.5 levels in Delhi’s air had peaked to around 40% in October. It came down only after Diwali (November 14). The low fire counts combined with rain and good winds post-Diwali helped clean up Delhi’s air from ‘severe’ to ‘poor’ and even ‘moderate’ for a day.

Delhi’s AQI has fluctuated between poor to severe and moderate in a matter of five days between November 13 and 17. From an AQI of 435 on November 15, which is in the severe zone, the air improved to poor (221) on November 16 and moderate (171) on Tuesday. However, it fell to poor again on Wednesday (211), as the contribution of stubble fires increased.

On Thursday, the air quality deteriorated further to the higher end of the ‘poor’ zone. The average air quality index (AQI) was 283 in the ‘poor’ zone. SAFAR said the deterioration in the air quality was mainly on account of a rise in the contribution of stubble fires to the city’s PM 2.5 levels to 20% on Thursday from 8% the previous day.

“The overall air quality of Delhi is likely to deteriorate to very poor by Thursday evening itself. Stubble burning’s share in PM2.5 in Delhi’s air is estimated at 20%. The air quality may improve marginally on November 22 with good wind speed likely around this time,” the SAFAR bulletin stated.

Also Read: Haryana logs 46% rise in farm fires this year

According to scientists at the India Meteorological Department (IMD), the average wind speed has been around 12-15 kmph, which is favourable for the dispersion of pollutants.

The deterioration in air quality can be attributed to a slight increase in fire counts, as the wind direction is north-westerly and is bringing fumes from Haryana and Punjab. Also, a fall in temperature may add to slow dispersion.

On Thursday, Delhi recorded its lowest minimum temperature of the season at 9.4 degrees Celsius, three notches below normal. The maximum settled at 25.6 degrees C, two notches below normal.

“The wind speed has remained good and is likely to be the same over the next two days. A dip in mercury and continuing stubble fires may result in slight deterioration,” said Kuldeep Srivastava, head of IMD’s regional weather forecasting centre.