Delhi’s air quality was recorded as ‘bad’ this morning but is likely to improve slightly due to wind speed.
New Delhi:
Air quality in the national capital was recorded in the ‘poor’ category this morning but is likely to improve slightly due to favorable wind speeds, according to government agencies.
The level of air pollution in Delhi had reached an eight-month high on Thursday, but dropped slightly on Friday with favorable wind speeds helping to disperse pollutants, even as the contribution of stubble burning to the concentration of Delhi’s PM2.5 increased to 18%.
The city posted an Air Quality Index (AQI) of 263 at 10 a.m. The 24-hour average AQI was 239 on Friday and 315 on Thursday, the worst since February 12 (AQI 320).
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’.
A senior scientist with the Indian Meteorological Department (IMD) said the maximum wind speed was 10 kilometers per hour on Friday. Today it is likely 12 km / h.
Calm winds and cold temperatures are unfavorable for the dispersal of pollutants.
The wind direction is expected to be north-northwest today, which is likely to increase the impact of stubble burning on Delhi’s air quality.
However, the Ministry of Earth Sciences Air Quality Early Warning System for Delhi said the ventilation rate, a product of mixing depth and average wind speed, is probably 9,500 square meters per second today. favorable for the dispersion of pollutants.
Mixing depth is the vertical height at which contaminants are suspended in the air. Reduce on cold days with calm wind speeds.
A ventilation rate of less than 6,000 m2 / second, with an average wind speed of less than 10 km / h, is unfavorable for the dispersion of pollutants.
According to the System of Research and Forecasting Weather and Air Quality (SAFAR), the contribution of agricultural fires to Delhi’s PM2.5 concentration increased from around 6 percent on Thursday to 18 percent on Friday.
It was only about one percent on Wednesday and about 3 percent on Tuesdays, Mondays, and Sundays. Air quality is expected to improve further to the lower end of the poor category by Sunday, SAFAR said.
The Central Pollution Control Board (CPCB) had said on Friday that weather conditions in Delhi have been “extremely unfavorable” for the spread of pollutants since September compared to last year.
The concentration of PM10 between September 1 and October 14 this year has been higher compared to the corresponding period last year, said CPCB member secretary Prashant Gargava.
The average ventilation rate has been 1,334 square meters per second in September and October this year, compared to 1,850 square meters per second during the corresponding period last year, the official said.
With a smaller acreage under non-basmati rice cultivation this time around, the CPCB member secretary expected the number of stubble burning incidents to be lower this year compared to 2019.
Non-basmati rice straw is considered useless as fodder due to its high silica content, which is why farmers burn it.
Mr. Gargava also said that the peak of stubble burning may not coincide with the peak of adverse weather conditions this year due to the early rice harvest.
With Delhi-NCR bracing for months of poor air quality, experts have warned that high levels of air pollution may exacerbate the COVID-19 situation.
Severe air pollution in Delhi is a year-round problem, which can be attributed to unfavorable weather conditions, agricultural fires in neighboring regions, and local sources of pollution.
According to an analysis by the Council on Energy, Environment and Water, a Delhi-based think tank, transportation is the largest contributor (between 18% and 39%) to Delhi’s air pollution.
Road dust is the second most important source of air pollution in the city (from 18% to 38%), followed by industries (from 2% to 29%), thermal power plants (from 3% to 11% ) and construction (8%).
(Except for the headline, this story has not been edited by NDTV staff and is posted from a syndicated feed.)
.
