Data-Based Mechanistic and Top-Down Modelling

The paper discusses the problems associated with environmental modelling and the need to develop simple, ‘top-down’, stochastic models that match the information content of the data. It introduces the concept of Data-Based Mechanistic (DBM) modelling and contrasts its inductive approach with the hypotheticodeductive approaches that dominate most environmental modelling research at the present time. The major methodological procedures utilized in DBM modelling are outlined and two practical examples illustrate how it has been applied in a hydrological and water quality context. The use of this same methodology as a basis for the evaluation and simplification of large deterministic simulation models is also discussed briefly.