Int. J. Environment and Pollution, Vol. 8, Nos. 3-6, 1997 39 1 Review of the requirements for models and model applications Frank de Leeuw RIVM, P.O. Box 1,3720 BA Bilthoven, the Netherlands Erik Berge DNMI, P.O. Box 43, Blindern, N-03 13 Oslo, Norway Knut Grrzrnskei NILU, P.O. Box 100, N-2007 Kjeller, Norway Maria Tombrou University of Athens, 33 Ippokratous Street, 10680 Athens, Greece Abstract: Requirements for models and model applications are reviewed on basis of the Dobns Assessment report and the practice in EU legislation and international organizations, and from the responses of a questionnaire sent to 38 European countries. Model applications are frequently used for regulatory and general assessment purposes by various users (scientists, air quality managers, policy-makers). Forecast models may play an important role in informing the public about smog episodes. While requirements in terms of compounds and spatial and temporal scales can be provided, the requirements on accuracy and documentation of models are less well defined. Keywords: air quality assessments, legislation, model applications, model requirements. Reference to this papershould be made as follows: de Leeuw, F., Berge, E., Granskei, K. and Tombrou, M. (1997) 'Review of the requirements for models and model applications', Int. J. Environment and Pollution, Vol. 8, Nos. 3-6, pp. 391-400. 1 Introduction As part of the work programme of the European Environment Agency (EEA), the European Topic Centre for Air Quality (ETC-AQ) has carried out three major projects to review requirements for air quality information and to develop tools for air quality assessment. The first two projects focus on the general approach to assessment and on the establishment of a European monitoring network and database. In the third project, called MA3, emphasis is on harmonization in the use of air quality models. As a first step (sub- project MA3-I), the requirements of models and model applications have been reviewed.' Copyright O 1997 Inderscience Enterprises Ltd.