Assessing the Relationship Between Traffic Activity and Urban Air Pollution in Dhaka Using QGIS and Emission Factor Methods
Bad air quality is one of the most serious issues cities are struggling with today, especially in rapidly growing megacities such as Dhaka. Increasing traffic volume and congestion make vehicular emissions one of the major sources of urban air pollution. This study examines the spatial correlation between traffic activity and air pollution concentration levels on selected road segments in megacity Dhaka. Traffic volume data were collected from six road segments along Mirpur Road and Kazi Nazrul Islam Avenue using videography-based surveys. Carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM2. were simulated by using emission factor methods. We extracted air pollutant concentration data from the Open-Meteo Air Quality API for each of these respective times and locations. Spatial emission distribution was visualized using a grid framework of 250 m × 250 m by utilizing Quantum Geographic Information System (QGIS) tools. The relationship between emissions and pollutant concentration were analyzed using regression. The results show that there is a strong correlation between the daily traffic emissions and the concentrations of air pollutants, with R² = 0.97 for CO (carbon monoxide) and R² = 0.93 for PM2.5 (particulate matter). The study highlights pollution hotspots on some major road segments where traffic density is high. The study emphasizes the significance of both traffic control methods and sustainable transportation planning especially for Dhaka in facilitating urban air quality challenges.