Investigating the effects of meteorology, built environment and traffic on near road air pollution
Notice bibliographique
Résumé
Metropolitan areas across the world have witnessed serious threats of increased dependence on vehicles as a result of rapid urbanization and changing land use patterns, leading to more people living and working in close proximity to busy highways and roads. As traffic-induced air pollution has been associated with health effects in epidemiological studies, investigations of traffic emissions and their dispersion in urban environments remain of utmost significance. This thesis aims at capturing the determinants of near-road concentrations of ultrafine particles (UFP) in the context of an urban canyon using linear mixed-effects models, and investigates the effects of meteorological conditions, built environment, land use and traffic flow. In addition, the absolute differences in the levels of UFP between both sides of the road were investigated. To reach these objectives, a data collection campaign was conducted on 16 weekdays in the months of March and April of 2015, along Papineau Avenue, a high-volume street in Montreal, Canada which runs north-south and serves as an important arterial road connecting the neighbouring cities of Laval and Longueuil with the Island of Montreal. Four data collection sites varying in land use, building height and road characteristics were identified, and air quality measurements were randomly scheduled to be conducted four days per week on the principle of each segment measured once in a one time period each day. On-site meteorological variables such as street level wind speed, wind direction, temperature and relative humidity were also collected by using a portable weather station, and a set of built environment characteristics were generated with geographical information systems (GIS). In addition, the traffic information regarding vehicle volumes and vehicle composition were counted manually. Two quantitative investigations were conducted. Linear mixed-effects models with random intercept were developed to explain both dependent variables: the natural logarithm of the mean UFP concentration and the absolute difference of UFP concentrations between two sides of the road. Notable findings include the association of lower temperatures and wind speeds with increased UFP concentrations. Furthermore, winds orthogonal to the road and lower relative humidity were shown to increase UFP concentrations as well as the differences between both sides of the road. Finally, built environment variables such as the presence of open areas and buildings on both sides of the road had a positive influence on the difference between UFP on the two sides. Together, these investigations of UFP concentrations help explain its interactions with meteorology, site characteristics, and traffic flow. Keywords: ultrafine particles; near-road air pollution; urban canyon; linear mixed-effects regression
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».