Optimisation model for water allocation in deficit irrigation systems I. Description of the model

In this paper, an economic optimisation model for hydrologic planning in de ficit irrigation systems is proposed. Irrigation water allocation between a gricultural demands is carried out following an economic efficiency criteri on with the aim of maximising the overall economic benefits obtained, alloc ating available water to each user as a function of the water's profit marg in. Water resources constraints in the system are considered. Aggregated ec onomic functions for each irrigation district are generated optimising the water used for the cropping pattern. Stochastic nature of water availabilit y and irrigation requirements have been taken into account. Due to the complexity of the system, the problem has been broken down into three independent optimisation sub-problems that perform hierarchically. Ea ch of these sub models takes into account a different resolution level of t he system: crop, irrigation district and the whole basin. The proposed model has been used in a subsequent paper to optimise water al location planning in a small basin in southern Spain; the Bembezar system. (C) 2001 Elsevier Science B.V. All rights reserved.