New Delhi: The Centre plans to clamp down on polluting farm fires by measuring the areas burnt instead of live blazes, after reports that farmers were burning paddy waste or stubble at times when satellites were not passing overhead.
India currently uses data from NASA satellites that pass twice a day over the northern states of Punjab and Haryana to monitor farm fires, which are a major contributor to the smog that envelopes the national capital region (NCR) each winter.
The Commission for Air Quality Management, a government body responsible for air quality in the NCR, said on Friday that India's space agency had been asked in January to develop a system to study burnt areas to count farm fires.
"That protocol has actually been developed and is currently being tested," Additional Solicitor General Aishwarya Bhati told the Supreme Court after an adviser to the court said on Monday that the current system counted fires over a limited time.
Some experts suspect that farmers have, over time, become aware of the surveillance period and shifted the time of burning their crop waste to evade the NASA satellites, because of which while counts were lower this year, pollution levels were not.
The government said on Friday that data from stationary satellites was "sub optimal" and not "actionable", dismissing an earlier direction from the court to use them instead.
Delhi has been battling hazardous air this month, with the air quality index (AQI) touching a peak of 494 on a scale of 500 on Monday, when farm fires also recorded a high of 2,893, prompting the government to restrict vehicle movement and construction and shift schools to online teaching.
India considers an AQI of 0-50 'good', and above 400 'severe', which poses a risk to healthy people and "seriously impacts" those with existing diseases.
Delhi recorded a 'very poor' AQI of 374 on Friday, authorities said, and the Ministry of Earth Sciences forecast it would remain in the same category (300-400) through this week.
Other countries in South Asia also battle toxic air every year as cold air traps dust, smoke, and emissions, and some studies say rising air pollution can cut a person's life expectancy in the region by more than five years.