A Simulation Study of Fishway

The paper argues that modelling provides a convenient and cost eeective means of characterizing and predicting the behaviour of environmental systems disturbed by man. A series of modelling criteria are suggested that aim at compelling modelling to work with current data, explicitly represent the current understanding of a system, include considerations of variability and address predictive uncertainty. Models which do so provide a rigorous framework for the comparison of alternative courses of action. As an example of the methodology, the problems associated with shway design, highlighting the required statistical analysis and insights, are discussed. Comparison of the modelling results to those gained from operational experience with real shways were used to validate model results and ensure model credibility. The models were then used to examine the eeect of design on interactions between pools in shways as a means of selecting the designs which minimized migration stress.