A NASA scientist told NDTV farm fires may increase in the next two weeks (File)
Winter is approaching, so is bad air quality in Delhi and the National Capital Region (NCR). Crop-residue or stubble burning in neighbouring Punjab and Haryana is likely to add to the city's worsening air quality index, or AQI.
We look at the farm fire situation in Punjab, based on data and imagery from the National Aeronautics and Space Administration (NASA) that has been tracking the situation for the past few years.
On October 25, 2019, the dots you see on this map of Punjab are of farm fires. It changes every year.
On October 25, 2020, the dots representing farm fires remain similar.
The same dots are seen every year - 2021, 2022, 2023 - in the sample imagery taken on the same date.
Now, just a couple of hours ago today, the NASA imagery shows a large area with the red dots, showing significant farm fires in Punjab.
To understand the data, we need to look at the trends between October 1 and 25, i.e. today. The data gives some interesting insights into the problem.
Between 2012 and now, except 2016, when farm fires really raged across Punjab, there has been a broad downward trend in crop residue burning. For example, 2020. But if you see 2023, the number indicates stubble burning in Punjab has been at its lowest since 2012.
"I was surprised to see that the fires in Punjab and Haryana have been lowest. We have never seen such low farm fires trend. There could be two reasons - the burning season has been delayed for some reason. It seems rainfall was in excess in Haryana and Punjab this July and August, which destroyed some crops," Hiren Jethva, Senior Research Scientist at Morgan State University NASA Goddard Space Flight Centre, told NDTV today.
"I am a bit afraid the (burning) season has been delayed, and we haven't seen the big fires, likely to happen in the coming two weeks," the scientist said.
Delhi's air quality was recorded in the "poor" category for a third day running on Wednesday and a major improvement is unlikely over the next few days, according to monitoring agencies. The city's average air quality index (AQI) stood at 238 at 10 am, worsening from 220 at 4 pm on Tuesday.
The average AQI was 196 in neighbouring Ghaziabad, 258 in Faridabad, 176 in Gurugram, 200 in Noida and 248 in Greater Noida.
According to the Centre's Air Quality Early Warning System for Delhi, the city's air quality is likely to oscillate between the "poor" and "very poor" categories over the next four to five days.
An AQI between zero 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.
Delhi's air quality had turned "very poor" on Sunday for the first time since May, mainly due to a drop in temperature and wind speed, which allowed pollutants to accumulate.