Stochastic Transfer Function Simulator of a 1-D Flow Routing

The paper presents an application of a Stochastic Transfer Function (STF) approach and a State Dependent Parameter (SDP) transformation of model variables to the combined reservoir management and flow routing problem on the Upper Narew River, NE Poland. The management objective is to reach required flow conditions in the reaches of an ecologically valuable river. A 1-D distributed flow routing model was designed for the study. However, both optimisation methods and reservoir management analysis require numerous model realizations which are computationally very expensive. A much more efficient solution consists of the application of a simplified STF simulator of river flow, which is calibrated on historical data and distributed model realizations for the parts of the river where the observations are not available. The model is stochastic, enabling derivation of prediction uncertainty in a straightforward manner. The obtained optimal control policy is tested on a fully distributed model.