The methodology developed especially for that purpose makes a throughout usage of CORINE L.C. layer to standardize the transfer of information between the administrative and the catchment layers. These layers represent the source of data on the one hand and the target for results on the other hand. This computation system is a part of NOPOLU system 2Â® ('NOPOLU2' in further citations), which is a comprehensive system designed for integrated emissions and impact assessment at any catchment / administrative scale. It benefits the following features.:NOPOLU2 is a software platform, developed by the BETURE-CEREC consulting firm. It comprises an original data base architecture, is linked to a GIS and manages different modeling software. A very important feature of NOPOLU2 is that it works on the 'exception' principle. This principle permits to deal simply with the numerous, and little weight items, whilst the less numerous or very important items can be dealt with at the utmost detail level. The burden for the user is reduced to the minimum.