Statistical Evaluation of the Distribution of PM10 and NO2 in the Ambient Air Due to Urban Forms: A Case Study in the Agglomeration of Cergy-Pontoise
Résumé
This work investigates the spatio-temporal trends of air quality and its relationship with urban form in the Cergy-Pontoise conurbation from April 8 to June 6, 2022. Air quality data were obtained from a network of 16 PM10 and NO2 sensors, installed specifically to fill the information gap regarding pollution levels achieved in its different areas. The evaluation of the relationship between urban form and pollution identified different sources of pollution between PM10 and NO2. Morphological parameters such as building density, degree of openness to the sky, nature of the substrate, distances to roads, and traffic flow/speed were shown to influence the concentrations of each pollutant. Concerning the temporal variability, the daily amplitudes are well-marked. NO2 concentrations are higher during peak hours and lower in the middle of the day. In the evening, the concentrations slowly decrease until the early hours of the morning. The diurnal cycle of PM10 shows a high morning peak and a lighter one in the late afternoon. Unlike NO2, PM10 concentrations are higher during the day due to turbulence and pollen activity.