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: Border coupled surface-subsurface flow model can well simulate, in physical mechanism, the non-linear interactions between surface flow and soil water, as well as soil water redistribution after border irrigation, playing an important role in large-scale border irrigation system evaluation. In this study, the one-dimensional complete hydrodynamic model was solved by the hybrid numerical method. The soil water hydrodynamic model was solved by the finite volume scheme with fourth-order accuracy for spatial discretization and the finite difference scheme with second-order accuracy for temporal discretization. The convergence value of surface water depth was obtained from the alternately iterative processes between mass conservation equations of complete hydrodynamic model and soil water hydrodynamic model at the same time step. The momentum conservation equation of complete hydrodynamic model was modified using the convergence value of surface water depth to obtain the updated velocity field. Finally, the coupled surface-subsurface hydrodynamic model was proposed based on the improvement of numerical solution methods and iterative coupling method.

Key words: border irrigation, iterative coupling method, numerical solution, surface water depth, mass conservation, momentum conservation

Published in: Journal of Hydraulic Engineering, Vol. 44, No. 5, 2013