Evanet-terra - evaluation and network of EC decision support systems in the field of terrestrial radioecological research

The EC 3. and 4. framework program have produced several models and Decision Support System (DSS) in order to assess the radioactive contamination of terrestrial ecosystems. However a critical evaluation of such systems had not been undertaken. The EVANET-TERRA network has been established in order to perform such a task. Results from three scenarios used to test the models will be presented. South Finland (VAMP scenario) and Friuli Venezia Giulia (Italy) concerning the rural environment and Bad Waldsee State Forestry (South Germany) for the semi-natural ecosystem. The accuracy with which the models fitted the known historical data has not been the only factor used to assess the models performance. Model detail, complexity, outputs uncertainty and models sensitivity have also been taken into account. For example rural models have been tested on two spatial scales: national (South Finland) and regional (Friuli Venezia Giulia, Italy), giving the opportunity to establish a relationship between the spatial scale used and model complexity. Complex and detailed models may give a more accurate prediction than 'simpler' models, if applied at a local scale, where the uncertainty on the input parameters is relatively low. At greater spatial scales larger uncertainty on the input parameters is likely and the complex model may give a prediction which is less accurate that of a simpler models. These considerations are an important factor in the discussion on model complexity, in relation to operational scale. The EVANET-TERRA project has produced a synthesis of the current state of terrestrial radioecological models, and recommendations have been made for further research needs. A DSS demonstrator has been produced, which applies and summarises the issues raised in the project. (author)