Alternative ways of developing relationships between the parameters of conceptual hydrological flood routing models and the physics (understood as the hydrodynamic model or as the real system) have been examined. Three deterministic and two stochastic methods of synthesis of conceptual parameters were studied. The results offer aid in identification of conceptual parameters when modelling systems for which no historical time series of inflow-outflow data are available (e.g. ungauged rivers or river engineering design).