Van Rijn

The van Rijn sediment transport formula are given by (1984a,b; 2007a,b)

1)	$\begin{array}{l}\displaystyle q_{bk}^{*}=0.015Uh\left(\frac{U-U_{crk}}{\sqrt{R_{k}gd_{k}}}\right)^{1.5}\left(\frac{d_{k}}{h}\right)^{1.2}\end{array}$

2)	$\begin{array}{l}\displaystyle q_{sk}^{}=0.012Uh\left(\frac{U-U_{crk}}{\sqrt{R_{k}gd_{k}}}\right)^{2.4}\left(\frac{d_{k}}{h}\right)d_{k}^{-0.6}\end{array}$

where

$\begin{array}{l}{q_{bk}}^*\end{array}$ = fractional bed-load sediment transport potential [L²/T]

$\begin{array}{l}{q_{sk}}^*\end{array}$ = fractional suspended-load sediment transport potential [L²/T]

$\begin{array}{l}R_{k}\end{array}$ = $\begin{array}{l}ρ_{sk}/ρ_w−1\end{array}$ = submerged specific gravity of a particle [-]

$\begin{array}{l}ρ_{sk}\end{array}$ = sediment density [M/L³]

$\begin{array}{l}ρ_{w}\end{array}$ = water density [M/L³]

$\begin{array}{l}U\end{array}$ = effective depth-averaged current velocity [m/s]

$\begin{array}{l}U_{crk}\end{array}$ = critical depth-averaged velocity for incipient motion [m/s]

The van Rijn formulas were originally proposed for well-sorted sediments. The formulas have been modified here for nonuniform sediments by replacing the median grain size with the grain class diameter and multiplying the critical depth-averaged current velocity with a hiding and exposure correction factor.