基于有效剪力的河口潮流挟沙力计算与检验

Calculation and verification of estuarine tidal current sediment carrying capacity based on effective shear

河口潮汐流是典型的非均匀、非恒定和周期性的水体运动。在研究潮流挟沙力问题中,利用水流对泥沙输移的有效剪力方法,即从总剪力中提取水流对泥沙颗粒的有效部分,可以排除非均匀、非恒定和形体阻力等影响。首先说明了有效剪力法计算潮流挟沙力的步骤,然后选用1994-2018年10个典型河口的实测潮流泥沙资料,对潮流挟沙力计算的有效剪力法、能量法、极值法和经验法进行了对比检验。结果表明,有效剪力法具有较高的计算精度和较强的实用性。此外,利用有效剪力法的潮流挟沙力公式进行计算,无需实测资料率定且普适性好,便于在无资料或缺乏实测资料地区使用。

Estuarine tidal flows are typical non-uniform,unsteady and periodic movements of water bodies. In studying the carrying capacity of tidal sediment,the effective shear method,which is to extract the flow that is effective on sediment particles from the total shear force,can eliminate the effects of inhomogeneity,instability and form drag. This study first introduces the steps of effective shear method in calculating the tidal current sediment carrying capacity. Then,the tidal current and sediment datasets of 10 typical estuaries from 1994 to 2018 are selected to carry out a comparative test on the effective shear method,energy method,extreme value method and empirical method. The results show that the effective shear method is more practical and has higher accuracy. In addition,the formula of sediment carrying capacity based on effective shear stress reflects the mechanical nature of tidal current sediment carrying movement,and the calculation can be done without calibrating the measured data and has good universality,which is convenient for use in estuary areas without or lacking measured data.