中文摘要：

本文根据流速与含沙量分布，研究了悬移质积点法对粗颗粒含沙量测验误差。首先指出无论从输沙率还是从悬浮高度看，粗颗粒悬移质集中于河底，致使水文测验中的一些测验方法（如一点法、二点法、三点法等）带有较大的误差。进而分析了各种测法对粗颗粒的相对误差，并且随着颗粒变粗，误差愈来愈大，以致不能接受。这种情况在水库下游河道冲刷过程中，会在一定程度上出现，必须重视研究和调整测验方法。最后通过与长江委水文局在沙市及监利两水文站试验结果对比，证明本文理论上的分析是可信的。

英文摘要：

This paper analyzed the error of coarse sediment concentration measuring in suspended load integrating method, according to velocity and distribution of sediment concentration. It was considered that the coarse suspended loads would be concentrated on the river bottom in view of sediment discharge or suspending height, which would lead to error of some measuring methods. The relative errors of various coarse grain measuring methods were also analyzed. The results show that the error will be bigger and bigger to inacceptable along with the particles getting coarser, which will appear during scouring in the lower reaches of reservoirs. For this reason, the concerned study should be made and the measuring methods should be regulated. It is proved that the con- clusion is credible in theory by contrasting the experiment results from the hydrometric stations of Shashi and Linli.