A proper understanding of the interaction of irrigation and drainage canals with an aquifer system is necessary to improve the performance of irrigation. This mechanism must be studied with a detail sufficient to identify operational guidelines for specific portions of an irrigation and drainage system. Numerical simulation models provide a useful support since specific operational procedures of irrigation and drainage canals can be evaluated in this way. Regional hydrological models of surface water and groundwater have been applied to an irrigated area of 36,000 ha in the province of Mendoza, Argentina. The use of such models can support decision-making on water management aspects. The benefit of a physically-based model is its use in situations with changing conditions affecting the hydrological system. An important aspect is the need to simulate the hydrological processes as accurately as possible and to include operational irrigation practice. The drawback of a modelling approach is the great demand for reliable input data.
- soil water balance