Selecting an Air Quality Model

A robust modelling strategy starts with the assessment question and the level of detail required.

We determine whether a study requires screening, refined dispersion modelling or specialist assessment of odour, chemistry or accidental releases.

Technical selection

A proportionate modelling approach

We select models to answer the assessment question efficiently and defensibly, considering available data, receptors, terrain, emissions and applicable requirements.

1

Meteorological basis

Meteorology underpins pollutant transport and dispersion. Depending on the study, we use observations, representative stations or WRF-derived modelled fields.

2

Screening assessment

Screening tools such as SCREEN help establish whether a refined dispersion assessment is required.

3

Refined dispersion modelling

Where required, dispersion models estimate concentrations and potential areas of influence using emissions, meteorology, terrain and source characteristics.

4

Specialist applications

Where warranted, we assess photochemical pollutants, odour impacts or accidental release scenarios using appropriate specialist tools.

Common applications

Tools selected for the assessment question

WRF meteorology

WRF generates spatial fields of wind, temperature, stability and mixing where site-specific modelled meteorology is required.

Screening assessment

SCREEN provides an initial indication of potential effects and whether a refined dispersion modelling study should be undertaken.

CALPUFF and AERMOD dispersion modelling

CALPUFF and AERMOD are widely used to assess impacts from primary pollutants in environmental studies and permitting work.

Odour assessment

Odour studies apply specific assessment criteria and metrics to evaluate potential effects on communities and sensitive receptors.

Accidental release and risk assessment

For accidental releases of hazardous substances, the model is selected for the substance, release conditions, duration and risk question.

Photochemical modelling

CAMx or WRF-Chem may be considered for secondary formation, ozone, secondary PM2.5 or regional transport in specific cases.

Not sure which modelling approach is appropriate?

We can define a proportionate, technically robust approach based on the assessment question, available data and applicable requirements.

Contact us