Two-dimensional model development and validation of surface water flow for border irrigation under anisotropic roughness

It has an important theoretical and practical significance that an appropriate roughness model of border fields is adopted for evaluating and optimizing border irrigation system. Based on the two-dimensional complete hydraulic model of basin irrigation with vector type and constructing a basin surface anisotropic roughness model in source roughness vector by using tensor inverse operation, the two-dimensional surface water flow model of border irrigation under anisotropic roughness was developed. Base on the typical border irrigation experiments, the simulation effects of the proposed model and the model under isotropic roughness were analyzed and compared. The results showed that compared with the surface water flow model under isotropic roughness, the average relative error between simulation value and observation value of the proposed model decreased by 3.08-6.83percentage point in the advance phase of surface water flow, and 2.5-6.81percentage point in the recession phase. The results indicated that the two-dimensional surface water flow model of border irrigation based on anisotropic roughness can improve simulation effects of surface water flow and provide a good numerical simulation tools for border irrigation system design and performance evaluation.