Modelling of hydrological rainfall-runoff processes is facilitated by the application of the systemtheoretical approach to linear, nonlinear and stochastic models. To this purpose, the variables involved in methods for determinating areal precipitation and baseflow separation are discussed. The convolution theorem in the theory of linear systems and the mathematical transform technique (Laplace-, Z-transformation) are used to identify characteristics of the watershed, and simulate hydrological processes. To support the calculation of model output functions, computer programs are included in...