Meta-model of an irrigation district distributed-parameter model

The release policy for a reservoir’s network can be designed by solving a multiobjective control problem. However, the use of resolution algorithms based on stochastic dynamic programming, with their high computational requests, imposes strong simplification in modelling the water system. In particular, downstream irrigation districts are often described as static subsystems, i.e. assuming an a priori trajectory of the water demand, while the use of the available simulation models is precluded due to their complexity. To overcome this problem, this study proposes the identification of a meta-model, i.e. a model of a simulation model, for describing an irrigation district. The meta-model computes the overall water deficit in the district, based on meteorological inputs and the water supply from an irrigation canal. Even if the meta-model is very simple, it can be given a physical interpretation in relation to the simulation model behavior. Results obtained with the original model and the meta-model over a real world case study, an irrigation district in the Padana plain, Italy, are presented.