GRAP-4 Imposed as Delhi AQI Worsens
Curbs tightened hours after GRAP-3 as air quality slips into ‘Severe Plus’ category
- CAQM invokes GRAP-4 across NCR with immediate effect
- AQI rises from 431 at 4 pm to 441 by 6 pm
- Stricter curbs added to existing GRAP I, II and III measures
- CAQM cites adverse weather, not local emissions, for spike
GG News Bureau
New Delhi, 13th Dec: Hours after GRAP-3 restrictions were imposed, the Commission for Air Quality Management (CAQM) on Saturday evening tightened curbs further by invoking Stage-IV of the Graded Response Action Plan (GRAP) across Delhi and the National Capital Region.
GRAP-3 measures were introduced earlier in the afternoon after the Air Quality Index (AQI) crossed the 400 mark, entering the ‘Severe’ category. However, worsening conditions prompted authorities to escalate restrictions within hours.
According to CAQM, the AQI stood at 431 at 4 pm and showed an increasing trend, reaching 441 by 6 pm. Under the GRAP framework, air quality is classified into four stages — Poor (AQI 201–300), Very Poor (301–400), Severe (401–450) and Severe Plus (above 450).
“Keeping in view the prevailing trend of air quality and in an effort to prevent further deterioration, the CAQM Sub-Committee on GRAP has decided to invoke all actions envisaged under Stage-IV of the extant GRAP — ‘Severe+’ air quality — with immediate effect across the entire NCR,” the commission said in a statement. It added that these measures would be in addition to restrictions already in force under Stages I, II and III.
Explaining the sudden spike in pollution levels, CAQM said adverse meteorological conditions, rather than local emissions, were primarily responsible for the deterioration in air quality.
The commission pointed to a feeble Western Disturbance approaching north-west India, which led to reduced wind speed, at times turning calm, a shift in wind direction from westerly to easterly, and increased moisture in the lower atmosphere. Such conditions during winter, it said, are conducive to smog and fog formation, resulting in poor dispersion and trapping of pollutants near the surface.
“Owing to these unfavourable meteorological conditions, a sudden deterioration in air quality has been observed,” CAQM said, adding that the situation would be closely monitored in the coming days.
