Special Geosciences Dept. Seminar: Air pollution in Urban street canyons - the influence of urban design
Prof. Liora Malki, UCL
Abstract:
Despite past improvements in air quality, very large parts of the population in European urban environments still breathe air that does not meet European standards let alone the health-based World Health Organisation Air Quality Guidelines. In the past decade there has been a substantial increase in findings that Air pollution, and in particular PM (particulate matter) is associated with poor health. Road traffic emissions are seen as the main source of air pollution in London and in most large cities. Therefore the urban environment has a large number of local sources of street level pollution, which varies throughout the city, in combination with a highly dense population exposed to the pollution. A particular problem arises in urban street canyons - long streets blocked on both sides by continuous tall buildings - which prevent ventilation of the street from the atmosphere above. This results in low airflow, stagnant recirculating air and buildup of pollution and heat in the street. This seminar will present results of CFD modelling and physical modelling in the laboratory, as well as field monitoring campaigns. The impact of street geometry and local features on pollution concentrations will be discussed, accounting for issues such as variations of roof height, local traffic lane position, variable wind, and trees.
Seminar Organizer: Prof. Eyal Haifetz