Optimization of furrow irrigation systems with continuous flow using the software applied to surface irrigation simulations - SASI

Surface irrigation systems still remain the most used irrigation system worldwide mainly due to its energy savings capacity and ease of operation. However, they show low performance level as a consequence to the general design and inadequate management. Therefore, the aim of this study was to develop a tool capable of optimizing the performance level of furrow irrigation systems with the continuous flow from successive simulations of the advance phase and predictions of performance parameters in irrigation systems. The proposed model, written in DELPHI 5.0 programming language and called Software Applied to Surface Irrigation Simulations (SASIS) had its validation tested for different field conditions. The results showed that the applied flow rate plays a decisive role on the performance parameters of irrigation systems with the best performances flow rates close to the minimum allowable levels. The field parameter that most impairs the optimization of the irrigation performance is infiltration, while the length and slope did not decisively interfere in optimization, which can be achieved for a wide range of values ​​for these parameters, and also in soils with high infiltration rates. The great difficulty in optimization is to minimize percolation losses, but in soils with low infiltration rates, both percolation and runoff losses can be easily minimized. The SASIS model has been an effective mechanism in performing numerous simulations within a flow range between minimum and maximum, aiming to determine the relationship between flow rate and water application efficiency, percolation and runoff rates and hence optimize the performance of furrow irrigation systems with continuous flow.   Key words: Furrow irrigation, flow rate, performance.