Potential areas of crop residue burning contributing to hazardous air pollution in Delhi during the post‐monsoon season
Md. Hafizur Rahman, Nimish Singh, Seema Kundu, Arindam Datta
Abstract
Abstract Severe daily ambient particulate matter concentrations <2.5 μm (PM 2.5 ) (>400 μg m –3 ) have been recorded in Delhi, India, for about 50 d in the post‐monsoon season (October–November) from 2016 to 2019. Monthly average ambient PM 2.5 concentrations during the period followed the order: September (63.0 ± 3.6 μg m –3 ) <listp October (145.8 ± 7.3 μg m –3 ) < November (233.0 ± 11.5 μg m –3 ). Crop residue burning has been reported as one of the major sources of ambient PM 2.5 in Delhi during the period. This study analyzed the effect of meteorological parameters and crop residue burning on the ambient PM 2.5 concentration in Delhi during the period using the dataset from one of the official monitoring stations, the Hybrid Single‐Particle Lagrangian Integrated Trajectory air parcel back trajectory model, and a satellite‐based active fire dataset for the years 2016–2019. The study suggests that crop residue burning events at Sangrur, Mansa, Bhatinda, Patiala, Ludhiana, Barnala, and Patiala (0.5° by 0.5° grid size) districts contribute to the severe PM 2.5 concentration in Delhi during November. A significant negative relationship of daily PM 2.5 concentrations with meteorological parameters (wind speed: r 2 = –.36, p < .05; planetary boundary layer height: r 2 = –.45, p < .05) and a positive relationship with the crop residue burning event ( r 2 = .46, p < .05) that occurred 3 d earlier were recorded. This study can help policymakers undertake location‐specific actions based on meteorological forecasts to reduce the cost and improve the effectiveness of policy actions to reduce the effect of crop residue burning on the ambient PM 2.5 concentration in Delhi during the post‐monsoon season.