Nodal Point Relation for the Distribution of Sediments at Channel Bifurcation

Abstract

This technical note explores the applicability of the general nodal point relation to describe the distribution of sediments at channel bifurcation. Experiments were conducted in a physical model of channel bifurcation to estimate the coefficient and exponent of the nodal point relation for different nose angles and upstream discharges. It was found that the nose angle is the major variable for the distribution of sediments to the downstream branches. The value of the exponent k found from experimental results was compared with that of a theoretical analysis. For a stable equilibrium, the value of k is greater than 5∕3 from theoretical consideration when the Engelund–Hansen sediment transport formula is used. This was confirmed from the experimental results. This suggests that the distribution of sediments at channel bifurcation can be expressed by the general nodal point relation.