Model predictive control (MPC) is used to manage water systems, and its performance depends on the (internal or control-oriented) model it is based on. Several models for the hydraulics of open water systems are presented in literature and used in applications, but their performance has not yet been investigated systematically, and no guideline exists on which model to select for a certain channel. The aim of this research is to present a guideline for model choice based on the geometry of the channel and the flow conditions. The guideline is developed by first categorizing the channels into four types, followed by performing time-domain, frequency domain, and closed-loop tests for all models and channel types. The evaluation of the tests shows that for short and wave-dominated channels, the Muskingum, Integrator Delay, and Integrator Delay Zero models perform the best, while for longer channels the linear inertial model is the most suitable. Finally, a decision-tree is presented how to choose the model. Lastly, a decision-tree is introduced to aid in the selection of the most appropriate model. Irrigation channels, drainage channels, reservoirs are crucial for us and they have to be managed. Water in them should be distributed safely, on time and satisfying all necessities, for example, irrigation, fishing, flood protection. This is achieved by controlling these water systems with hydraulic structures such as gates, weirs and pumps. One way of controlling these structures is so called model predictive control (MPC), a technique which is based on a simple model of the water channel and with the help of mathematical optimization calculates what the hydraulic structures should do, for example, open a sluice gate. There are several different simple models are available for this technique. This article describes a technique how to choose the best simple model for a given open water channel for MPC, based on the geometry and the discharge in the channel-which is easy to be estimated. Therefore it is a straightforward guide of choosing a model for MPC of open channels. Simple models for open water channels for control purposes are compared through open and closed-loop simulation tests and frequency response Open channels are categorized based on their geometry and flow conditions and for each category a model is recommended A guideline is given for internal/surrogate model choice for control purposes
