Controller configurations for irrigation channels derived from sequential minimum variance control

In this paper, we examine the feedback and feedforward paths of sequential minimum variance controllers for irrigation channels. From a water conservation point of view, it makes sense to order the variables in importance form the downstream end of the channel to the upstream end with the flow over the last gate as the most important variable. The resulting controller configuration is essentially the distant downstream configuration commonly used in decentralised control of demand driven if irrigation systems, In this configuration, a gate controls the water level immediately upstream of the next downstream gate, and the last gate controls the flow over the last gate. This finding means that a downstream controller configuration for decentralised control is suitable both form a demand and a water conservation point of view. Controller configurations resulting form different orderings of the output variables are also examined.