INTEGRATED AND STOCHASTIC FEATURES OF URBAN DRAINAGE SYSTEMS

An analysis has been made of the uncertainty of input parameters to deterministic models, with emphasis on the models for the sewer system. For each parameter a sensitivity analysis and for all the parameters a Monte Carlo analysis has been made. The analysis reveals a very significant uncertainty that can be decreased; but cannot be eliminated as significant to engineering application. Stochastic models have a potential for dealing with these uncertainties. That applies also to the treatment plant and to the receiving water models. The three components in the system have been analysed as a whole. Examples show that an integrated analysis is required in order to find economically optimised solutions that comply with environmental standards.