 The objective of the Modelling Special Interest Group is to bring together CASANZ members who have an interest in the development and/or application of atmospheric dispersion modeling in order to exchange ideas, identify common problems, inform members of new developments, and establish, as appropriate, a 'ModSIG view' on issues of relevance.Dispersion modelling is becoming more and more a part of licensing emissions to the atmosphere throughout Australia, and there is growing awareness of the role that air quality modelling can play in areas such as air resource management, risk assessment and land-use planning.The Odour Special Interest Group is an important forum for the exchange of information, and in encouraging improved practices in odour measurement, modelling, assessment, control, management and monitoring.