Modelling air quality

Air quality models are important tools to manage air quality.

These tools are used to explore which sources have the largest impacts on air quality and to evaluate the future effectiveness of proposed regulatory programs.

The outcomes of the models also support plans and policies to manage emissions from pollution sources.

Modelling vs. monitoring

Although monitoring a pollutant provides characteristics of concentrations, it cannot provide all the answers.

While monitoring is restricted to a limited number of locations, air quality modelling provides a cost-effective approach to air quality assessment in large urban or industrial regions for a large number of pollutants.

Predicting impacts

Modelling is also needed to assess air quality in future situations.

When meteorological and emissions data are available, air pollutant levels can be predicted to assess the impacts of population growth on air quality.

Another use is to predict the impact of planning decisions, such as the placement of roads and the location or expansion of residential and industrial areas.

How air quality models work

Air quality models use complex mathematical techniques to simulate the physical and chemical processes that affect air pollutants as they disperse and react in the atmosphere.

Models need a range of input data, such as pollutant emissions from different sources in the region, meteorological data and land surface topography.

Even the most complex models will always be an approximate representation of the actual situation.

Where possible, comparing the pollutant level predictions from the models against observed data from monitoring stations ensures that the results from the air quality models are accurate.