Field measurements based model for surface irrigation efficiency assessment

• Published in: Agricultural water management Vol. 156; pp. 30 - 42
• Main Authors: Canone, D., Previati, M., Bevilacqua, I., Salvai, L., Ferraris, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2015
• Subjects: Agricultural hydrology; Computational fluid dynamics; Computer simulation; Farming; Fluid flow; Hydraulics; Infiltration; Irrigation; Irrigation efficiency; Irrigation modelling; Soil moisture; Surface irrigation; Irrigation modelling; Agricultural hydrology; Irrigation efficiency; Surface irrigation
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2015.03.015

•Soil hydraulic properties and infiltration were measured in farms.•Water infiltration was modelled together with overland flow.•It was possible to evaluate irrigation efficiency.•The model allows to simulate the effects of actual irrigation practices. Within scenarios of water scarcity, the irrigation efficiency plays an increasingly strategic role. In this paper, a method that uses an advance-infiltration model based on four field measurements and the soil particle size distribution is proposed to estimate border-irrigation efficiencies. This method was applied to fifteen irrigation events and the application, storage and distribution efficiencies were estimated. The advance-infiltration model was validated against soil moisture measurements. The field-scale saturated hydraulic conductivity was estimated by model fitting to the measured depth of water infiltration. The sensitivity of the modelled irrigation efficiency to the operational surface irrigation parameters was evaluated by simulating seven irrigation scenarios based on field-collected data. The infiltration profiles obtained by the proposed method were in agreement with the soil moisture measurements. The maximum difference between simulated and measured infiltration depth was 0.018m. The field-scale saturated hydraulic conductivity values were in agreement with the infiltrometer tests results. The analysis of both simulated scenarios and monitored irrigation events highlighted the need for farmers to reduce the flow rates and increase the duration of irrigation events, in order to improve the irrigation efficiencies.