The ratio of measured to total sediment discharge

作     者：Chun-Yao Yangn Pierre Y.Julien 

作者机构：Department of Civil and Environmental Engineering Colorado State University 

出 版 物：《International Journal of Sediment Research》 (国际泥沙研究(英文版))

年 卷 期：2019年第34卷第3期

页      面：262-269页

核心收录：

学科分类：08[工学] 081502[工学-水力学及河流动力学] 0815[工学-水利工程] 

基　　金：the Korea Water Resource Corporation (K-water) for providing the field measurements and financial support 

主　　题：Modied Einstein Procedure Total sediment load South Korea 

摘      要：It is important to examine the ratio of measured to total sediment discharge to determine the error in measured sediment transport rates from depth-integrated samplers. The ratio of measured to total sediment discharge as well as the ratio of suspended to total sediment discharge are examined based on the Modified Einstein Procedure. Both ratios reduce to a function of the ratio of shear velocity, u?, to the fall velocity, ω, of suspended material, u?=ω, and the ratio, h=ds, of flow depth, h, to the median grain size of bed material, d50. In rivers transporting fine material(such as silt or clay), the ratio of suspended to total load is a function of the ratio, h=d50. In this study, it is found that the ratio of measured to total load becomes a simple function of flow depth. For fine sediment transport, with a Rouse number(Ro) o 0:3,at least 80% of sediment load is in suspension when h=d50415, and at least 90% of sediment load is measured from depth integrating samples when h 4 1 m. Detailed measurements from 35 river stations in South Korea demonstrate that sand sizes and finer fractions predominantly are transported in suspension. Also, at least 90% of sand and finer fractions are transported in suspension in gravel and sand bed rivers when the discharge is larger than the mean annual discharge.