Sensitivity Analysis and Evaluation of Hydraulic Models in Designing Furrow Irrigation

Various methods have been developed for designing surface irrigation. It seems that using Hydraulic models is the most accurate method to design surface irrigation. In this study, Full Hydrodynamic (HD), Zero Inertia (ZI) and Kinematic Wave (KW) models were evaluated and sensitively analyzed, in order to simulate different phases off low under corrugation condition. Three field data sets with different soil texture were used to evaluate these models. The results showed that all models performed satisfactory in advance phase prediction. In contrast, in recession time, compared to the advance phase, all three models simulation were less accurate. On the basis of these results in each three furrow, the Full Hydrodynamic model with mean coefficients of R2, RMSE and EF (0.9983, 2.4541 and 0.9817 for advance phase) and (0.9852, 4.2722 and -1.4435 for recession phase) simulates different phases of flow more accurately than the other models. Furthermore, the infiltration evaluation results showed that performance of the models with regard to predicting infiltration at various soil textures is different. So in light textured furrow, the mean absolute error (1.49%) has the lowest value, as it simulates infiltration parameters more precisely than the others. Sensitivity analysis of hydraulic models in corrugation irrigation showed that change in input data, including input discharge, flow cut-off and infiltration equation coefficients parameters, has a significant impact on water application efficiency, water requirement efficiency, distribution uniformity coefficient and runoff ratio. Therefore, it is necessary to be more accurate when measuring these parameters.

کلیدواژه ها:

Furrow ، Hydraulic Models ، Sensitivity Analysis ، Surface Irrigation