Crop burning responsible for 19% of Delhi’s air pollution, finds SAFAR
The raging farm fires in states bordering Delhi-NCR and those across the international border in Pakistan caused a 7% increase in the city’s air pollution due to stubble burning on Tuesday.
On Tuesday, the contribution of stubble burning in Delhi’s air pollution was around 19%, up from Sunday’s 12% , said scientists.
Meteorologists, however, said that the overall air quality didn’t see a major dip, because of strong surface winds that are presently sweeping across the national capital.
On Tuesday, the average Air Quality Index (AQI) value of Delhi at 4pm was 207, slightly better than Monday’s 249. On a scale of 0 – 500, an AQI value between 201 and 300 is tagged as poor quality of air. During the peak pollution period, this value shoots beyond 400, denoting severe category of pollution.
Scientists from government agencies, however, said that the air quality was likely to deteriorate temporarily over the next two days, primarily because of unfavourable meteorological conditions.
According to System of Air Quality and Weather Forecasting And Research (SAFAR), the pollution forecasting wing of the Union government, the contribution of stubble burning to city’s air pollution was around 19%. It was 12% on Sunday and 14% on Monday.
“A gradual increase in the stubble burning activity has been noticed and fire count has reached one-fourth of its peak value observed last year,” said SAFAR in a statement issued on Tuesday.
But even though pollutants from stubble burning regions of Punjab, Haryana and neighbouring Pakistan are being transported by northwesterly winds towards Delhi-NCR, they are not being able to accumulate in the city because of strong winds.
While Delhi needs a minimum windpseed of 10km per hour to keep its air clear, the windpseed in city has been hovering above 20kmph over the past two days at least.
This situation is however likely to change over the next 48 hours and air quality is likely to dip temporarily before it improves again. According to SAFAR’s forecast, the AQI value could hit the upper limits of the poor zone or may even touch the very poor category because of low wind speed. It would however improve again on Friday because of an approaching western disturbance.
“The AQI is likely to plunge because of an anti-cyclonic condition which is expected to develop in the first week of November. The associated sinking motion will make the atmosphere very stable with calm surface winds. Both will lead to stagnant weather conditions which would favour rapid fine particulate matter formation and accumulation of pollutants,” said a scientist from SAFAR.