Delhi Air Pollution: How Geography And Weather Conditions Worsen Delhi’s Air Quality?

Delhi air pollutionThe Delhi air pollution has reached “severe” levels, leading to the activation of Stage IV measures under the Graded Response Action Plan (GRAP) in Delhi-NCR. By 6 a.m. on Monday, Delhi’s Air Quality Index (AQI) had escalated to 481, placing it in the “severe plus” category.

Supreme Court questions Delhi government

On Monday, the Supreme Court questioned the Delhi government about the delay in enforcing Stage IV of GRAP, given the worsening air quality. The court proposed an order to ensure that these measures remain in place, even if the AQI improves and falls below 300, unless permission is granted to relax them. During the hearing, Justice A. S. Oka emphasized the court’s position, stating that the government would not be allowed to revoke Stage IV measures without explicit approval, regardless of temporary improvements in AQI.

Delhi air pollution: Stage IV restrictions

The Delhi government, represented by its counsel, informed the court that Stage IV had been implemented starting Monday. Under these restrictions, the entry of trucks into Delhi is prohibited, except for those transporting essential goods or services. The court, however, sought an explanation for the delay in implementation. The counsel noted that the AQI had been monitored over the past few days, and an improvement was anticipated. Justice Oka remarked that GRAP IV should have been enforced immediately upon the AQI reaching severe levels, as delays could not be justified under such critical circumstances. The court also requested details of the government’s actions to address the issue.

Delhi air pollution and stubble burning in Punjab

Stage III measures, implemented on November 14, already included moving junior classes to online learning and restricting certain vehicles, including private BS-III petrol and BS-IV diesel vehicles, as well as inter-state buses and non-compliant vehicles. The Odd-Even rule could also be considered if the situation persists.

Delhi Chief Minister Arvind Kejriwal, who has previously attributed the city’s poor air quality to stubble burning in Punjab, highlighted the challenges farmers face, stating that farming is essential for their livelihoods. Punjab, which is now governed by the Aam Aadmi Party (AAP), has seen debates over the role of stubble burning in the region’s air pollution.

Weather pattern and Delhi geography

The phenomenon of air pollution in Delhi and the Indo-Gangetic plains is multifaceted. While stubble burning contributes to pollution, it is not the sole cause. Air quality is influenced by multiple factors, including emissions, weather patterns, and local geography. During the winter, wind patterns shift to a north-westerly direction, carrying pollutants from Punjab’s crop burning to Delhi and the broader region. Cooler temperatures lower the inversion height, trapping pollutants closer to the ground and worsening air quality.

Geography also plays a significant role in exacerbating pollution in the Indo-Gangetic plains. This region is flanked by the Himalayas to the north and elevated plateaus to the south, creating a basin-like structure that traps pollutants. Delhi’s location and topography, including the presence of the Aravalli hills, make it particularly prone to critical pollution episodes during the October to December period when meteorological and environmental conditions converge.

Read More: Delhi Air Emergency: Supreme Court Upholds GRAP-IV MeasuresTiil Further Orders