New Delhi – The Commission for Air Quality Management (CAQM) lifted restrictions under Delhi Grap Stage 4 on Tuesday following a marginal improvement in the capital’s air quality. The 24-hour average air quality index (AQI) stood at 378, categorized as “very poor” at 4 pm, marking a significant drop from the reading of 410 categorized as “severe” recorded at 4 pm on Monday. The removal of Delhi Grap Stage 4 comes after a three-day streak where the AQI had consistently remained at 400 or higher.
The air quality had been particularly hazardous over the weekend, with readings of 440 in the severe category on Sunday and 400 in the very poor category on Saturday. The lifting of Delhi Grap Stage 4 brings relief to various sectors that had been operating under strict restrictions.
Air Quality Forecast and Weather Predictions
According to the Air Quality Early Warning System (EWS) for Delhi, a forecasting model under the Centre, the capital’s air quality is likely to remain in the very poor category from January 21 through January 23. Despite Delhi Grap Stage 4 being lifted, forecasts indicate that the AQI will continue to fluctuate between very poor and poor ranges for the subsequent six days, from January 24 onwards.
The forecast also shows that a western disturbance is approaching, potentially bringing light rain and gusty winds on January 23. This weather change could further improve air quality conditions beyond the current Delhi Grap Stage 4 removal.
Key Restrictions Lifted With Delhi Grap Stage 4 Removal
The removal of Delhi Grap Stage 4 has resulted in several significant changes to operational restrictions in the capital. Trucks and diesel-operated BS-4 Heavy Goods Vehicles (HGVs) are now permitted to enter Delhi again, easing logistical challenges that businesses had been facing under Delhi Grap Stage 4 restrictions.
Construction and demolition activities for linear projects have been allowed to resume following the Delhi Grap Stage 4 lifting, though private construction and demolition activities remain prohibited. This partial resumption allows essential infrastructure projects to continue while maintaining some level of pollution control.
The mandatory restriction on schools to conduct hybrid classes for students in grades six through eleven (excluding grades 10 and 12) has also been lifted with the Delhi Grap Stage 4 removal. Schools can now return to normal operations, providing relief to students and parents who had been managing hybrid learning schedules.
Vehicle Movement and Government Restrictions
Additionally, a restriction imposed by the Delhi government on non-Delhi registered vehicles below BS-6 standards has been lifted following the Delhi Grap Stage 4 removal. This allows greater mobility for vehicles entering the capital from neighboring states and regions.
The Delhi Grap Stage 4 measures were initially invoked on Saturday, January 17, when the day’s AQI began rising rapidly and crossed 400 in the evening. Typically, Delhi Grap Stage 4 is implemented when the AQI is expected to cross 450, though authorities can invoke it preemptively based on deteriorating conditions.
CAQM’s Decision Rationale
The CAQM issued a statement on Tuesday explaining the decision to lift Delhi Grap Stage 4, citing the forecast for “very poor” air quality. The commission also considered “the disruptive nature of restrictions” and “the trend of improvement in the average AQI of Delhi” when making this decision regarding Delhi Grap Stage 4.
Air Quality Station Data and Regional Variations
Central Pollution Control Board data at 8 am on Tuesday showed that of the 39 active ambient air quality stations in the city, 23 were still recording readings in the severe category despite the Delhi Grap Stage 4 removal. However, by 7 pm, only five stations remained in the severe category as winds picked up during the day, allowing better dispersion of pollutants.
On Monday, as many as 25 stations were in the severe range, while on Sunday, 33 stations recorded severe air quality levels. Wazirpur emerged as the worst impacted location on Tuesday morning, recording a reading of 445, followed by Anand Vihar at 444. On Monday, Wazirpur had peaked at 473, followed by Vivek Vihar at 472. On Sunday, Anand Vihar peaked at 497, only three points short of the maximum reading of 500.
Weather Conditions and Temperature Updates
The India Meteorological Department (IMD) has issued a yellow alert for Friday, forecasting chances of very light to light rain. There are also possibilities of gusty winds reaching speeds up to 40 kilometers per hour during the day, which could further aid in pollutant dispersion beyond the Delhi Grap Stage 4 period.
Delhi witnessed shallow to moderate fog on Tuesday morning, with visibility dropping to 200 meters at Safdarjung and 700 meters at Palam. The minimum temperature stood at 7.2°C, approximately normal for this time of year, compared to 7.7°C on Monday.
The maximum temperature reached 25.7°C, six degrees above normal, following the unusually warm 26.7°C recorded the previous day. The maximum temperature is forecast to hover between 22-24°C on Wednesday and between 24-26°C on Thursday as weather patterns continue to evolve after the Delhi Grap Stage 4 removal.
