The air quality of Delhi and Gurugram remained in the ‘poor’ category on Saturday, while that of Noida deteriorated to the ‘very poor’ level, according to the Central Pollution Control Board data.
The air quality of Delhi is expected to improve on Monday and Tuesday, as per System of Air Quality and Weather Forecasting and Research (SAFAR).
The Air Quality Index (AQI) of Delhi on Saturday was 287, and the values for Gurugram and Noida were 280 and 309, respectively, as per CPCB’s 4 p.m. bulletin, which is an average of the past 24 hours. Delhi’s AQI on Friday was 239 (poor).
An AQI between 0 and 50 is considered ‘’good’’, 51 and 100 ‘’satisfactory’’, 101 and 200 ‘’moderate’’, 201 and 300 ‘’poor’’, 301 and 400 ‘’very poor’’, and 401 and 500 ‘’severe’’.
“The overall Delhi AQI is in the upper end of ‘poor’ category as of Saturday morning and likely to marginally deteriorate to lower end of ‘very poor’ later during the day mainly due to low surface wind. However, Wind speed is likely to slowly improve from Sunday, leading to relatively better dispersion in Delhi. But, AQI is predicted to stay in the higher-end of ‘poor’ to the lower end of ‘very poor’ category for Sunday, and likely to improve to ‘poor’ category by October 19 and further improvement is expected by October 20, but well within poor range,” SAFAR said in a statement.
The fire count due to stubble burning in Haryana, Punjab, and neighbouring border regions of Delhi was 882 on Friday, as per SAFAR. The contribution of stubble burning in neighbouring States to the PM2.5, a chief pollutant, levels in Delhi is estimated to be around 19% on Saturday.
The impact is likely to “increase significantly” by October 19, the Ministry of Earth Sciences’ Air Quality Early Warning System for Delhi said.
The wind direction is favourable for transport of pollutants due to stubble burning. Also, local wind speed is less and this leads to pollutants not getting dispersed easily and in turn negatively affects the air quality.
“The local wind speed is calm, almost nil during the night and during the day time it is 8-10 km/hr, which is also less. Dispersion of pollutants happens at this speed, but it is less. The local wind speed has to be above 15 km/hr and continue for a good amount of time to disperse pollutants properly,” said Kuldeep Srivastava, head of the regional forecasting centre of the IMD.
Meanwhile, no rain is expected in Delhi for the next seven days, which may result in higher dust pollution.
Officials said fire tenders sprinkled water in Wazirpur, Dwarka and Ohkla as part of measures to curb dust pollution. The Delhi Fire Services conducted the operation.
