Analyses and Comparisons of the Relationships of Alluvial Resistance

The new relationship of the height of dunes on alluvial bed is presented. The law of alluvial resistance in the transition regime is found. The comparisons among six important relationships of alluvial resistance are made. Einstein's and Ning qian's relationships are suitable for sandy rivers only in transition regime. Changhua Li's relationship can be applied to sandy rivers in the lower and transition regimes. Engelund's equations are a mean situation for sandy channels except for very fine sand and gravel bed and the transition regimes, it is not suitable for θ_*'>1.96. Hayashi's equation is not suitable for sandy rivers with smaller slope. The author's resistance equaltions can be used in all of the three regimes, various sediment diameter and flow depth, its verification shows that the average error of calculated flow depths is very small.