River flow forecasting. Part 2. Algebraic development of linear modelling techniques

The role of linear input-output models in hydrological forecasting is discussed. The algebraic analysis of linear systems with single or multiple input and single output is presented in outline. The least squares method of system identification is discussed in the context of recursive and off-line estimation, with and without volumetric and shape constraints. An alternative means of imposing shape constraints, via parametric modelling, is also discussed. A procedure for ‘updating’ is presented for models used in real-time forecasting.