AQI in Delhi-NCR soars again to ‘very poor’ zone over fall in temperature, farm fires
The minimum temperature in Delhi is expected to drop another 2-3 degrees Celsius over the next two days, which could lead to a rise in smog, weather officials said.Updated: Nov 12, 2019 05:35 IST
The air quality in the National Capital Region deteriorated on Monday, straying deeper into the “very poor” category, which experts attributed to a fall in temperature and winds bringing pollutants from farm fires in neighbouring states while warning that the region may be back in the “severe” zone by Wednesday.
The minimum temperature in Delhi is expected to drop another 2-3 degrees Celsius over the next two days, which could lead to a rise in smog, weather officials said.
According to the Central Pollution Control Board (CPCB)’s 4pm bulletin, the average air quality index (AQI) for the preceding 24 hours rose from 321 on Sunday to 360 on Monday. By 11pm, it was up to 381. An AQI of 401-500 is classified as “severe”.
Experts largely attributed this rise in pollution to the wind speed, which is low at the ground even as the north-westerlies brought in smoke from farm fires in neighbouring states, particularly Punjab.
The effective stubble fire count in Punjab and Haryana on Sunday was 1,846, according to estimates by System of Air Quality and Weather Forecasting and Research (SAFAR), Union ministry of earth science’s weather and air quality forecasting centre. “Stubble plume intrusion is expected to increase,” it said. According to data from the government of Punjab, a total of 43,181 farm fire incidents have been reported in the state since September 23.
“The main reason behind the deteriorating air quality is the slowing down of wind. On Monday, the wind speed was 10kmph, while on Sunday it was nearly 20kmph. The situation might deteriorate further till November 14. On November 15, 16 and 17, the wind speed will rise again,” said Kuldeep Srivastava, head of the India Meteorological Department’s (IMD) regional weather forecasting centre.
Scientists also blamed the change in wind direction from south-easterly to north-westerly, which, they said, is not only bringing in pollutants from the stubble-burning regions of Punjab and Haryana but also cold winds from the snow-clad Himalayan mountains. When the air is colder, it becomes heavier and thus unfavourable for the dispersion of pollutants. On Monday, the maximum temperature was 28.5 degrees Celsius, normal for this time of the year, while the minimum settled at 13.5 degrees Celsius, a notch below the season’s average.
After a marginal dip at 8am, the PM2.5 (fine particulate matter) — one of the most harmful aerosols — levels in the city’s air also saw an upward movement as the day progressed. CPCB data showed that at 8am, the average PM2.5 level was 180ug/m3; this increased to 212 at 12pm and 226 at 5pm, nearly four times the safe limit of 60. “It [the rise in pollution] worries me too. I worry about your family as much as mine. Through collective efforts, there’s 25% reduction in pollution for rest of year. Till October 10, Delhi air was good, after which it started going bad due to stubble burning. It happens every year at this time. We are working to find a solution,” tweeted Delhi chief minister Arvind Kejriwal.
Looking at the dip in the air quality, CPCB extended the ban on polluting industries in Delhi-NCR till November 13. After that, the air quality is expected to improve and the ban may be lifted [from November 14]. “From November 14 winds are likely to be stronger resulting in faster dispersal of pollutants. We will review the ban again on Wednesday,” read the minutes of the CPCB-led Graded Response Action Plan (Grap) task force meeting.
The Supreme Court-mandated Environment Pollution (Prevention and Control) Authority (Epca) approved the recommendations. SAFAR also said that the share of stubble burning in the PM2.5 levels in Delhi will shoot up on Tuesday.
“On November 12, the air quality is likely to deteriorate further and may remain in the upper end of ‘very poor’ category and may also reach ‘severe’ levels,” SAFAR’s forecast read.
The agency explained in its prediction that the upper atmosphere winds are bringing in farm fire smoke, while the calm winds on the surface is aggravating local pollution.
The Delhi government, meanwhile, continued its criticism of the governments of Punjab and Haryana for showing “lack of seriousness and political will” in addressing the problem of stubble burning. Delhi environment minister Kailash Gahlot said that he has written to the chief ministers of the two states, urging them to take “immediate action” to stop stubble burning incidents.
“Stubble burning is going on unabated in neighbouring states despite the Supreme Court holding every official accountable. Despite this environment ministers of Punjab, Haryana, Uttar Pradesh and Rajasthan did not attend the meeting. The seriousness required to deal with the issue has been missing on their part,” Gahlot said.
He accepted that unpaved roads and burning of waste in vacant plots are key local sources of pollution in Delhi. The responsibility of controlling polluting activities such as these lies with the civic bodies, he said. “The commissioners of the municipal corporations and Delhi Development Authority (DDA) vice-chairman gave a miss to the meeting called by the Centre. This shows their lack of commitment to the problem,” he said.
A senior DEMS (Department of Environment Management Services) officer of the South Delhi Municipal Corporation (SDMC), on condition of anonymity, said the three municipal corporations have been putting in consistent efforts towards pollution mitigation since October 15, when the Graded Response Action Plan (GRAP) came into force. “Under the guidance of EPCA and with daily review meetings being taken by the Prime Minister’s Office (PMO) itself, the corporations have so far issued about 8000 challans for environmental violations like garbage burning and operating open ovens, and imposed penalties of ?4 crore almost. About 30,000 tonnes of Construction & Demolition (C&D) debris has been removed and around 6,000 km distance has been covered by our water sprinkling machines,” the official added.