选取合理的畦面糙率模型,对于利用畦灌水流数值模型准确地评价和优化畦灌系统性能具有重要的理论与现实意义.该文利用二维全水动力学畦灌模型,采用张量逆运算等数学处理方法,在源项糙率矢量中构建畦面糙率各向异性模型,构建起基于畦面糙率各向异性的二维畦灌地表水流运动模型.基于典型畦灌试验结果对比分析糙率各向异性与各向同性畦灌模型的模拟效果.结果表明,与各向同性相比,所有实例各向异性糙率值下的水流推进过程实测与模拟值之间的平均相对误差值减小3.08～6.83百分点,水流消退过程实测与模拟值之间的平均相对误差值减小2.5～6.81百分点.采用各向异性糙率描述畦灌地表水流运动过程,可明显改善畦灌模拟效果,为开展畦灌系统设计与性能评价提供了实用可靠的数值模拟工具.%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 2.5-6.81 percentage 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.
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