一维畦灌地表水流-土壤水动力学耦合模型Ⅱ:验证  

Coupled surface-subsurface hydrodynamic model for border irrigation Ⅱ:Validation

作　　者：董勤各[1,2] 许迪[1,2] 章少辉[1,2] 白美健[1,2] 

机构地区：[1]中国水利水电科学研究院水利研究所,北京100048 [2]国家节水灌溉北京工程技术研究中心,北京100048

出　　处：《水利学报》2013年第6期726-733,共8页Journal of Hydraulic Engineering

基　　金：国家863计划重点项目课题(2011AA100505);国家自然科学基金资助项目(51279225;51209277)

摘　　要：根据室内外试验观测数据和模拟结果,对比分析了基于混合数值解法求解的一维畦灌地表水流运动模型以及基于二阶时间离散精度有限差分法-四阶空间离散精度有限体积法解算的一维土壤水动力学模型的模拟效果,检验了现有迭代耦合模式改善后的模拟性能。结果表明,利用混合数值解法求解一维畦灌地表水流运动模型具有比Roe有限体积法更好的数值计算稳定性和收敛性;与一阶时间离散精度有限差分法-二阶空间离散精度有限差分法及一阶时间离散精度有限差分法-二阶空间离散精度有限体积法相比,采用二阶时间离散精度有限差分法-四阶空间离散精度有限体积法解算一维土壤水动力学模型具备较好的模拟精度、质量平衡性和收敛速率。与此同时,改善后的迭代耦合模式呈现出较好的模拟精度和质量守恒性,且计算效率平均提高0.7倍以上。基于数值解法和迭代耦合模式同步改进后构建的一维畦灌地表水流-土壤水动力学耦合模型,具有提高模拟精度和计算效率的良好能力。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 meth- od for temporal discretization, and the one-dimensional surface flow hydrodynamic model, solved by the hy- brid numerical method, were compared based on soil columns and field irrigation experiments, and the sim- ulated performance of the improved iterative coupling method was tested. The results show that the one-di- mensional surface flow hydrodynamic model solved by the hybrid numerical method exhibits better computa- tional stability and convergence performance than that of Roe finite volume method. The proposed one-di- mensional 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 it- erative 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 im- proving simulated accuracy and computational efficiency.

关 键 词：畦灌 迭代耦合模型 数值解法 模型验证 模拟效果 

分 类 号：S275.3[农业科学—农业水土工程] S147.3[农业科学—农业工程]