DONG Qin-ge 1, 2, XU Di 1, 2, ZHANG Shao-hui 1, 2, BAI Mei-jian 1, 2 (1. China Institute of Water Resources and Hydropower Research, Beijing 100048, China, 2. National Center for Efficient Irrigation Engineering and Technology Research, Beijing 100048, China)

Abstract: Simulated effects of the one-dimensional soil water dynamics model, solved by the fourth-order accuracy finite volume method for spatial discretization and the second-order accurate finite difference method for temporal discretization, and the one-dimensional surface flow hydrodynamic model, solved by the hybrid numerical method, were compared based on soil columns and field irrigation experiments, and the simulated performance of the improved iterative coupling method was tested. The results show that the one-dimensional surface flow hydrodynamic model solved by the hybrid numerical method exhibits better computational stability and convergence performance than that of Roe finite volume method. The proposed one-dimensional soil water dynamics model presents better computational accuracy and convergence rate than that solved by the second-order accurate finite volume method or second-order accurate finite difference method for spatial discretization with first-order finite difference method for temporal discretization. The improved iterative coupling method presents satisfactory simulated precision and mass conservation, and shows higher computational efficiency of more than 0.7 times than that of the traditional iterative coupling methods. The one-dimensional border irrigation coupled surface-subsurface flow hydrodynamic model, developed based on the improved numerical solution methods and iterative coupling method, has satisfactory performance of improving simulated accuracy and computational efficiency.

Key words: border irrigation, iterative coupled model, numerical solution, model validation, simulated effect

Published in: Journal of Hydraulic Engineering, Vol. 44, No. 6, 2013