Urban air quality-pollution levels and risk assessment

"What would happen (to pollution levels) if we did nothing?"

"What difference would it make if we restricted the times that cars could be used, or the volume of traffic?"

Pollution is one of the issues that pre-occupies society today, and these are the types of question being asked by the decision makers at both local and national government level. Engineers can help to answer them by using the powerful computational techniques that are available to model the spread of pollution both within a city and in the atmosphere.

Rex Britter is familiar with such decision making processes, having spent ten years advising and monitoring research programmes for the European Commission DG12 on Major Technological Hazards and Industrial Safety. "The models for predicting dispersion of pollutants on a city scale or on the scale of a street are already pretty good, but on a neighbourhood scale, that is in the prediction of how people or buildings within say 500m of the source of pollution are affected, there is still work to be done," he explains. "One aspect of this problem that we are working on is how do you describe cities in terms of the urban morphology? We are looking at descriptors of the city that have to be modelled to adequately describe a city in mathematical terms. We can combine information from GIS systems and satellite imagery to build up topographic maps of cities which can then be used to determine how pollution spreads."