Since October, the Delhi-NCR region has seen air quality dropping to dangerous levels.
Residents in Delhi and its adjoining areas saw a thick layer of smog covering the region, significantly dropping the air quality to the 'Severe' category after the Air Quality Index crossed the 400 mark and disrupted flight operations due to low visibility.
The Commission for Air Quality Management (CAQM) has called the early-morning dense smog an "episodic event".
Thick smog caused zero-metre visibility at the Indira Gandhi International Airport at 8.30 am with the Runway Visual Range varying between 125 and 500 metres at different locations, the India Meteorological Department (IMD) said.
Since October, the Delhi-NCR region has seen air quality dropping to dangerous levels, with many contributing factors like vehicular pollution in the capital and stubble burning in Punjab and Haryana.
Pollution board CAQM said, "Today, Delhi's daily average AQI clocked 418 as per the 4 PM AQI Bulletin by CPCB. The CAQM Sub-Committee on GRAP accordingly took stock of the air quality scenario and the AQI forecast, including for the meteorological conditions as made by IMD/ IITM."
"The Sub-Committee noted this steep rise in AQI of Delhi owing to this episodic event, since this morning."
The board said they expect the situation to improve by tomorrow morning, "owing to stronger winds" and the "AQI, is expected to start showing a declining trend tomorrow onwards." They said the air quality is likely to move back to the 'Very Poor' category tomorrow.
On enforcing stage III of pollution measures, the panel said, "Comprehensively reviewing this scenario accordingly, it was decided by the Sub-Committee to keep a close watch on the situation, before invoking the stringent/ restrictive measures under Stage-III of GRAP and to review the status tomorrow."
In October, the panel implemented stage II of the anti-pollution plan in the city after the AQI crossed the 300 mark and has hovered mostly between 200-300 since then.
Under stage two of the GRAP or the Graded Response Action Plan, there will be restrictions on the use of coal and firewood as well as diesel generator sets in the Delhi-National Capital Region (NCR).
Mechanical sweeping and water sprinkling on identified roads will also be carried out daily, and dust control measures will be enforced at construction and demolition sites.
Further, traffic personnel will be deployed at congestion points, vehicle parking fees will be increased to discourage private transport and additional bus and metro services will be started.
Under stage III measures, there's a ban on non-essential construction work and the plying of BS-III petrol and BS-IV diesel four-wheelers in Delhi-NCR.