Research on discrimination of bed forms in the lower reach of Yellow River

Based on the bed form control factor theory and the existing flume experimental data, the correspondence between values taken by the control factor and different bed form configurations is analyzed. A bed form parameters including the particle Froude number and the relative depth (ratio of depth to median diameter of sediment particle) are proposed. In addition, a computational method on the basis of simplified control factor m, and its scope of application are introduced. The adaptability of the relationship between bed form control factor and the bed form parameter is discussed. With the relationship and the characteristics of bed form movement observed in the lower reach of Yellow River, a method to discriminate bed forms is established. The study suggests that the flow resistance characteristics in upper and lower flow regimes can be described by the control factor m, and the relationship between the control factor m and the bed form parameter exists not only in the laboratory flume experiments but also in the natural river systems. The preliminarily test of the established method to discriminate various bed form phases is done using the field observations. The result shows that the method is able to discriminate bed forms in different flow regimes in the lower reach of Yellow River.SCOPUS: ar.j