Delhi's air quality slips to 'very poor' category; stubble burning contributes 14 per cent to polluted air

Air quality in Delhi slipped to very poor category on Saturday with a steep rise in stubble burning in the last two days contributing to 14 per cent in the city's deteriorating air, authorities said.

According to the Ministry of Earth Sciences' forecast body SAFAR, Delhi's AQI slipped to a very poor category with PM 2.5 as the lead pollutant.

Favourable meteorological conditions lead to intrusion of stubble burning related air mass. With 1,572 effective fire counts as per SAFAR harmonised methodology which includes data of two ISRO satellites, the stubble burning contribution in Delhi's air has suddenly increased to 14 per cent.

Fire counts are gradually increasing and wind direction is favourable and coming from north-west direction at transport level (900 mb) for intrusion, SAFAR said.

It, however, said that rainfall is likely to happen on Sunday and improve the air quality but will remain in the 'poor' category.

According to the data from the Indian Agricultural Research Institute (IARI), as many as 1,948 farm fires were recorded in the last two days - October 15 and 16- compared to 1,795 incidents which occurred in an entire month till October 14.

In the last two days, 1,089 farm fires were recorded in Punjab, Haryana had 539 fires, Uttar Pradesh had 270 incidents, Rajasthan had 10 fires and Madhya Pradesh recorded 40 such incidents.

The data showed that the fire incidents recorded within two days are much higher than the incidents which occurred in the last 10 days till October 14.

A total of 1,008 fires were recorded in Punjab between October 6-14 and 463 fires occurred in Haryana during the same time.

According to the Decision Support System (DSS) developed by the Indian Institute of Tropical Meteorology-Pune (IITM), the ventilation index and the wind speed in the national capital will be lower than average in the next two days which is unfavourable for dispersion of pollutants.

However, the air quality is likely to improve owing to the rainfall activities on October 17 and 18 which is favourable for removal of pollutants, IITM said, adding that the air quality is likely to remain largely in moderate category.

Stubble burning in the neighbouring states significantly contributes to the air pollution in Delhi.

The active fire events due to rice residue burning were monitored using satellite remote sensing, following the new Standard Protocol for Estimation of Crop Residue Burning Fire Events using Satellite Data.

Punjab had recorded 1.02 lakh incidents of stubble burning in 2016. The number decreased to 67,079 in 2017; 59,684 in 2018 and 50,738 in 2019 from October 1 to November 30. The state logged 79,093 such incidents last year, according to the IARI.

Haryana saw 15,686 farm fires in 2016; 13,085 in 2017; 9,225 in 2018; 6,364 in 2019 and 5,678 in 2020.

Punjab and Haryana attract attention during the paddy harvesting season in October and November.

Farmers set their fields on fire to quickly clear off the crop residue before cultivating wheat and potato. It is one of the main reasons for the alarming spike in pollution in Delhi-NCR.