A STATISTICAL METHODOLOGY FOR THE EVALUATION OF LONG-RANGE DISPERSIONMODELS - AN APPLICATION TO THE ETEX EXERCISE

This paper describes the statistical methodology applied to evaluate t he performance of the long-range dispersion models that were used in t he modelling activities of ETEX (European Tracer EXperiment). The avai lability of a large number of models makes this exercise rather unique . These models are used for the practical purpose to quantify the cont amination effects over a vast area, following a hypothetical accidenta l release of harmful material. This makes the quality judgement that c ould be attributed to the results of each model particularly important . The statistical indicators considered to be the most effective for t he evaluation of long-range dispersion models are introduced and comme nted, with specific examples in the frame of ETEX simulations. The imp ortance of using several indices and critically interpreting the resul ts is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.