TY - JOUR ID - 75550 TI - Development of a Numerical Model for Furrow Irrigation by Coupling 1D Saint-Venant and 3D Richards’ Equations JO - Iranian Journal of Soil and Water Research JA - IJSWR LA - en SN - 2008-479X AU - Naghedifar, Seyed Mohammadreza AU - Ziaei, Ali Naghi AU - Ansari, Hossein AD - Department of Water Science and Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad (FUM), Mashhad, Iran Y1 - 2020 PY - 2020 VL - 51 IS - 6 SP - 1529 EP - 1541 KW - Overland Flow KW - Subsurface flow KW - Advance phase KW - redistribution DO - 10.22059/ijswr.2020.296550.668487 N2 - Development of numerical models for management and assessment of irrigation systems is an important step for establishing farm decision support systems. In this study, a coupled model has been developed for simulation of furrow irrigation using 1D fully hydrodynamic form of Saint-Venant equations and 3D fully-form of Richards’ equation. The Saint-Venant equations have been discretized by an explicit scheme while the Richards’ equation has been solved by an implicit scheme. Furthermore, coordinate transformation technique was employed to handle non-orthogonal grids of 3D Richards’ equation. The model was subsequently validated using experimental and numerical data and in all cases acceptable accuracy was observed. Root mean square error and mean absolute error for the advance phase were 0.63 and 2.63 sec, respectively. Furthermore, the maximum root mean square error and the mean absolute error for pressure head distribution were obtained 0.24 and 0.45 m, respectively.  Finally, the proposed model was employed to simulate furrow irrigation for five irrigation events and the results were analyzed. The results showed that the proposed model is able to simulate advance phase of furrow irrigation. UR - https://ijswr.ut.ac.ir/article_75550.html L1 - https://ijswr.ut.ac.ir/article_75550_53dbc172ccaa2061912635f07d330a2f.pdf ER -