Categorization of trapezoidal open channels based on flow conditions for the choice of simple models

Many applications in water management rely on keeping the water levels of an open water channel within given bounds, e.g. irrigation canals, drainage systems, and hydropower systems. These are all open water channels where the water level is influenced by several known and unknown factors like precipitation, operation of structures, etc. Water levels can be efficiently controlled by model predictive control (MPC). In MPC the optimization algorithms give advice at every time step based on the current state of the system as well as on the expected future state. These algorithms need a model to predict the response of the system to the control inputs. In most cases, the need to guarantee convexity of the optimization problem leads to the requirement that these models should be linear. To date, several such linear models are available in literature, which are suited for control purposes. However, the choice between these models is not straightforward. In this work, we extend a categorization of open channels, based on which the choice of a simple model can be advised.