为了明确南水北调中线工程渠道糙率的合理取值, 分别选取杨开林公式、美国垦务局公式、美国陆军工程兵团公式, 以及优化方法来计算糙率, 并构建南水北调中线总干渠水力学模型进行检验。将模型方法应用到刁河节制闸-湍 河节制闸渠段的 10 组稳定工况时, 4 种方法计算出的糙率值分别为 0.01538、0.0156、0.01389 和 0.0169, 代入水力学模型计算的刁河节制闸各工况闸后水位与实测值的相对误差总和分别为 0.1744% 、0.1586% 、0.3028% 和 0.0947%。 4 种方法得到的糙率值代入水力学模型的模拟精度中, 优化方法最好, 建议作为中线渠道糙率计算的方法。

In order to determine the reasonable channel roughness values for the Middle Route of South-to-North Water Diversion Project, we selected three methods ( Kai-lin Yang fo rmula, U.S. Bureau of Reclamation formula, and U.S. Army Corps of Engineers formula) and established one optimized method to caculate the roughness; then we tested the validity of the roughness values using the hydraulic model for main canal of South-to-North Water Diversion Project. The model and the method were applied to ten stable working conditions of the channel from Diaohe Gate to Tuanhe Gate. The roughness values caculated by the four methods were 0.01538, 0.0156, 0.01389, and 0.0169, respectively. Then the roughness values were put into the hydraulic model to caculate the water level behind Diao he Gate. The sum of relative error between caculated and measured values of the ten working conditions were 0.1744% , 0.1586% , 0.3028% , and 0.0947% , respectively . Results showed that the optimized method was the best at caculating channel roughness. We suggest that it be applied to South-to-North Water Diversion Project.

水体污染控制与治理科技重大专项( 2017ZX07108-001) ; 国家科技支撑计划( 2015BAB07B03) ; 流域水循环模拟与调控国家重点 实验室代表性成果培育课题( 2016CG05)