This paper presents a model, called IrrigaLS, to analyze the water allocation for irrigation. The water volumes stored in the soil and in the superficial reservoirs constitute decision variables of the network flow model in the allocation analysis. IrrigaLS is one of the programs that form the base of models of the decision support system called AcquaNet. Evaluations have shown that IrrigaLS is efficient at simulating complex water resource systems under multiple usage condition. IrrigaLS allows the real water needs of the crops to be determined, it guarantees a minimum water supply to the crops during drought periods, as well as water saving by the inclusion of rainfall. It also makes possible the choice of soil moisture target, to differentiate the crops in relation to the water deficit sensitivity and to calculate the soil daily water budget. The fact that it takes into account the interactions between water, soil, weather and plant allows for a better approach to a more efficient water use as well as to estimate the agricultural production.
simulation model; optimization model; water resources planning
