Development and test of an evaluation protocol for heavy gas dispersion models

In order to improve the quality (i.e. fitness-for-purpose) of models used to describe the atmospheric dispersion of heavy gas, an evaluation methodology has been developed and tested through a small evaluation exercise. This activity was carried out by the Heavy Gas Dispersion Expert Group, which was set up by European Commission's Model Evaluation Group. Its objective was to develop a protocol for evaluation of the models and to make an overview of the experimental data available for such an evaluation. The main results of the Expert Group's activities are: (i) a tested heavy gas dispersion model evaluation protocol, (ii) a list and classification of available models and (iii) a list and classification of relevant data-sets. Furthermore, it is concluded that there is a need for a more extensive evaluation exercise and that the scientific evaluation requires more attention.