SIRR-MOD--A Decision Support System for Identifying Optimal Irrigation Water Needs at Field and District Scale

SIRR-MOD is a DSS integrating two numerical modules: (1) A agro-hydrological model (named FLOWS-HAGES) for simulating flow of water and solutes in heterogeneous agri-environmental systems; (2) A model for simulating the hydraulics of the irrigation network (named COPAM). FLOW-HAGES provides a daily list of hydrants opening based on water or crop criteria. Then, an optimal sequence of hydrants may be established by passing the volumes to be delivered to a model (COPAM) for simulating the hydraulics of the irrigation network, in order to guarantee that the discharges flowing inside the distribution pipes network are delivered under optimal pressure head distribution. In this paper, we only illustrated the potential of FLOWS-HAGES model in simulating the daily evolution of: soil water contents and pressure heads in the soil profile; water uptake; stress periods for each crop; return fluxes to the groundwater under pressurized irrigation systems and climatic conditions at district level. This methodology has been applied to establish irrigation scheduling over the irrigation season for sector 6 of the Irrigation District 10 in the "Sinistra Ofanto" irrigation system. Irrigation water volumes calculated by FLOWS-HAGES model were compared to the volumes delivered by farmers, showing irrigation simulated by the model more frequent than those supplied by the farmers and with lower irrigation volumes.